Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 49
3
Human Geography
and Water Resources
W
ater use and scarcity are functions of water model of gridded population counts, though, it is possible
supply and demand. This chapter focuses to at least estimate the current population of each country
on the demand for water, with an emphasis living in the watersheds of interest in this study. This can
on the social factors affecting water use and availability: be further segmented into coarse elevation zones (low,
population growth, distribution, and migration; types below 1,000 m; high, above 4,000 m; and moderate,
and distribution of water use including irrigation; clean between 1,000 and 4,000 m). In this report, the Com-
water and sanitation access; infrastructure; and institu- mittee uses both Global Rural Urban Mapping Project
tions. Finally it includes a discussion of methods for (GRUMP) (CIESIN, 2004) and Landscan (2010)
measuring and managing water scarcity. population data to estimate populations at risk, relying
on the former when estimating urban populations1 and
POPULATION DISTRIBUTION the latter when estimating population distribution per se.
AND MIGRATION Nepal and Bhutan are wholly contained within
the Ganges and Brahmaputra river basins, and most of
The study region includes some of the most densely Pakistan is found within the Indus Basin. Bangladesh
populated areas on Earth as well as some of the least lies within the Ganges, Brahmaputra, and Meghna
densely populated regions, with a stark increase in basins; and India has territory within all of these basins,
population density as one moves from the mountains to though much of India's land area also falls outside the
the ocean. As of 2010, India alone was home to about main study watersheds (Figure 3.1). Note, as discussed
1.2 billion people, while Bangladesh and Pakistan each in Chapter 1, that the population density of the Hima-
contained about 149 million and 174 million people, layan Endorheic basins is very small, and therefore the
respectively. Nepal had a smaller population of about Committee focused the discussions in this chapter on
30 million, while Bhutan was home to about 726,000 the Indus and Ganges/Brahmaputra basins. Estimates
people (United Nations, 2011a). of the shares of national populations living in these
The water dependencies and vulnerabilities of popu- basins are presented in Table 3.1.
lations living in lower-lying areas will be quite different In 2010, approximately 195 million people lived
from the dependencies and vulnerabilities of populations in the Indus Basin, with 16 percent of them (31.9 mil-
in higher-lying ones. However, demographic composi- lion) living at elevations above 1,000 m (Table 3.2).
tional data are collected through national censuses and In contrast, nearly all (97 percent) of the more than
surveys and are reported by administrative units, such
as provinces and states, which typically do not conform 1 GRUMP data rely primarily on nighttime lights to delineate
neatly to geographic features of interest, such as river urban areas and therefore provide a cross-nationally consistent basis
basins or zones of elevation. By using a spatial population by which to measure urban areas (Balk, 2009).
49
OCR for page 50
50 HIMALAYAN GLACIERS: CLIMATE CHANGE, WATER RESOURCES, AND WATER SECURITY
FIGURE 3.1 Population distributions in the HKH region. Population data were taken from the Global Rural/Urban Population Map-
ping Project. Dashed lines indicate disputed political boundaries, following the guidance issued by the U.S. State Department, and
this Committee takes no position on these boundary disputes.
TABLE 3.1 Shares of National Populations Living in 600 million people in the Ganges/Brahmaputra Basin
Hindu-Kush Himalayan Region Water Basins live at elevations below 1,000 m.2 Most of those living
National below 1,000-m elevation are in India (79 percent) and
Population Bangladesh (18 percent; Table 3.3). Even in Nepal,
Population National Living in
Country Basin in Basina Populationb Basins (%)
where 29 million people live in this basin, almost two-
Afghanistan Indus 10,636,154 31,412,000 33.9
thirds live below 1,000-m elevation. Even in mountain-
ous Bhutan, more than one-quarter of its population
Bangladesh Gang/Brahm 103,326,928 148,692,000 69.5
in the Ganges/Brahmaputra basin lives at an elevation
Bhutan Gang/Brahm 699,847 726,000 96.4
below 1000 m.
China Gang/Brahm 1,712,145
On a global scale, the countries of this region
Indus 35,585 1,348,932,000 0.13
encompass some of the world's poorest and least devel-
India Gang/Brahm 466,738,395 oped areas, alongside areas that are also experiencing
Indus 36,074,708 1,224,614,000 38.1 rapid economic growth. The region is characterized by
Nepal Gang/Brahm 28,951,851 29,959,000 96.6 relatively low shares of the population living in cities.
Pakistan Indus 148,104,460 173,593,000 85.3
a Landscan (2010). 2 In Bangladesh, furthermore, nearly 60 percent of the population
b United Nations (2011a). lives within 10 m of sea level and contiguous to the seacoast.
OCR for page 51
HUMAN GEOGRAPHY AND WATER RESOURCES 51
TABLE 3.2 Population in the Ganges/Brahmaputra and Indus Basins, by Elevation
and Country
Country/Basin 4,000 m
Afghanistan Population in Indus Basin 1,701,185 8,901,679 33,290
Share of basin population living in elevation zone 16.0% 83.7% 0.3%
Bhutan Population in Ganges/Brahmaputra Basin 193,974 496,887 8,986
Share of basin population living in elevation zone 27.7% 71.0% 1.3%
Bangladesh Population in Ganges/Brahmaputra Basin 103,326,928 -- --
Share of basin population living in elevation zone 100.0% -- --
China Population in Ganges/Brahmaputra Basin 1,433 866,630 844,082
Population in Indus Basin -- 1,084 34,501
Share of basin population living in elevation zone 0.08% 49.6% 50.3%
India Population in Ganges/Brahmaputra Basin 459,157,952 7,502,996 77,447
Population in Indus Basin 26,539,558 9,431,329 103,821
Share of basin population living in elevation zone 96.6% 3.4% 0.04%
Nepal Population in Ganges/Brahmaputra Basin 19,239,788 9,604,421 107,634
Share of basin population living in elevation zone 66.5% 33.2% 0.4%
Pakistan Population in Indus Basin 134,747,024 13,159,600 197,836
Share of basin population living in elevation zone 91.0% 8.9% 0.1%
Total population in Ganges/Brahmaputra Basin 581,920,075 18,470,934 1,038,149
Total population in Indus Basin 162,987,767 31,493,692 369,448
TOTAL 744,907,842 49,964,626 1,407,597
SOURCE: Data from Landscan (2010).
In 2000, Pakistan had the greatest percentage--one- rapidly, with rates of urban growth that exceed those
third--of its population living in cities. Despite rela- historically found in the West. In all countries in this
tively low levels of urbanization, this region is home to region, the average annual rate of change of the urban
some of the world's largest cities: Dhaka (Bangladesh), population exceeds 2 percent, in Nepal and Bhutan,
Delhi (India), Kolkata (India), Mumbai (India), Kara- the rates exceed 4 percent per year (United Nations,
chi (Pakistan), Lahore (Pakistan).3 Cities are growing 2011b). Nevertheless, the pace of urbanization in
this region is not historically unusual (NRC, 2003a).
3 One thing that makes Asia stand out, particularly the subre-
Urbanization may also affect water demand. Wealthier
gions dependent on the water resources of the Indus and Ganges/
Brahmaputra deltas, is the number of extremely large cities, or the and more urban populations, for example, have differ-
phenomenon of urban "giganticism" (Preston, 1979). ent dietary possibilities and preferences than their rural
TABLE 3.3 Urban Population Projections as Percent of Total Population, by
Country 2010-2050.
2010 2015 2020 2025 2030 2035 2040 2045 2050
Bangladesh 28.07 30.80 33.89 37.35 41.045 44.84 48.69 52.57 56.415
Bhutan 34.71 38.54 42.40 46.23 49.97 53.62% 57.22 60.75 64.17
India 30.01 31.72 33.89 36.56 39.75 43.30 46.93 50.58 54.23
Nepal 18.62 21.58 24.78 28.18 31.74 35.47 39.38 43.42 47.56
Pakistan 35.90 37.67 39.88 42.53 45.62 49.07 52.54 55.98 59.37
SOURCE: Based on data from United Nations (2011b).
OCR for page 52
52 HIMALAYAN GLACIERS: CLIMATE CHANGE, WATER RESOURCES, AND WATER SECURITY
counterparts, and changes in diet (e.g., toward consum- less able to move away from it" (GO-Science, 2011).
ing more meat) can have implications for agricultural That said, those who migrate are by no means better off
water demand. than the native population in their places of destination.
Rural dwellers tend to be poorer than their urban New migrants often do not have access to land, hous-
counterparts, but there is also substantial urban poverty ing, safe water and sanitation, or public services (e.g.,
and slum-dwelling in this region. Water supply and schooling or health care).
wastewater services in cities and towns are often under-
developed, and many cities in the region are located in Projected Demographic Trends
areas of high flood potential, exacerbated by poor urban
drainage during monsoons (Moser and Satterthwaite, Key population-related questions of interest for this
2008). Urban poverty itself often exacerbates the devel- study include whether certain watersheds and elevation
opment of systems for delivery of water and sanitation, zones will experience higher rates of population growth
as well as access to those resources when such systems than others, and how the demographic composition of
are in place ( Johnstone, 1997). those specific areas will change. Existing demographic
Nevertheless, cities serve as major magnets for methods, however, do not allow one to make such fine-
migrants. Most migration takes place within country, grained projections. That being said, one thing that we
between cities themselves, and between rural areas do know about the distribution of future population is
and cities. International migration is a small share of that countries in this region will become increasingly
total migration, although some borders are effectively urbanized (Table 3.3) and that cities (which are pre-
more fluid than others (e.g., between Bangladesh and dominantly at lower altitudes) will continue to absorb
India).4 migrants in search of economic and other opportuni-
Although temporary migration has long been a ties. Migration has the potential to serve as an adaptive
strategy used by families and households to accom- strategy to environmental change--even as the cities
modate climate variability (especially flooding), there that receive the migrants cope with their own set of
is little evidence that climate change or other envi- economic challenges and environmental stresses and
ronmental factors (with the possible exception of vulnerabilities (Hardoy et al., 2001). However, many
long-term drought) result in major migration flows complex factors beyond environmental change con-
(McLeman and Smit, 2006; Tacoli, 2009). To the tribute to migration.
contrary, many countries in the region are known Country-level population projections are limited
for their high adaptive capacity. Yet, theoretically it by the fact that they do not have any population-
is possible that long-term changes to cropland and environment interactions or feedback loops built in.
losses of livelihood could make it more difficult to This will matter more as projections are made fur-
earn a living from farming. Such "livelihood fragility" ther into the future. Nevertheless, it can be said with
could affect migration over a much longer time span, substantial confidence that the populations of the
albeit through a pathway that is less direct than a single countries in this region will grow considerably over
climate-related event or change in the environment the next few decades. India alone is projected to add
(Raleigh, 2011). nearly half a billion people to its population between
Migrants tend to be younger and better educated 2010 and 2050 (Table 3.4). Larger populations will
than those who do not move, and it is these nonmovers result in increased demand for water and may exac-
who may be regarded as most vulnerable. A recent study erbate problems of resource scarcity and vulnerability.
found that migration has implications not just for the Over the longer term, though, rates of population
mover but for those left behind: "Poorer households are growth are projected to become smaller over time (see
likely to be `trapped' in circumstances where they are Table 3.5). The slowing of population growth will be
at once more vulnerable to environmental change and driven by declines in fertility rates, which are in turn
caused by, among other things, rising standards of liv-
4 The bulk of international migrants from Bangladesh, Bhutan, ing, decreases in childhood mortality rates, and better
India, Nepal, and Pakistan stay within the region (DRC, 2007). access to family planning.
OCR for page 53
HUMAN GEOGRAPHY AND WATER RESOURCES 53
TABLE 3.4 Population Projections by Country (thousands) 2010-2050
2010 2015 2020 2025 2030 2035 2040 2045 2050
Bangladesh 148,692 158,317 167,256 175,195 181,863 187,103 190,934 193,344 194,353
Bhutan 726 784 829 867 899 924 943 956 962
India 1,224,614 1,308,221 1,386,909 1,458,958 1,523,482 1,579,802 1,627,029 1,664,519 1,692,008
Nepal 29,959 32,581 35,164 37,653 39,943 41,977 43,749 45,257 46,495
Pakistan 173,593 189,648 205,364 220,609 234,432 246,789 257,778 267,240 274,875
SOURCE: Based on data from United Nations (2011b).
PATTERNS OF WATER USE tion, it follows that a conversion from natural land cover
to crops will decrease the amount of runoff that makes
Types of Water Use
its way into surface water or groundwater.
There are many ways to measure water use, and care For water to be useful, it must be available when
must be taken when comparing different metrics. The and where it is needed. Issues of water timing are often
most common type of water use measurement, and the critical for both blue and green water use. For instance,
subject of this report, is the quantity of water withdrawn many climates have a rainy period when available
or consumed for human purposes from surface water or water exceeds human demand and a dry period when
groundwater. This type is sometimes called "blue water" human demand exceeds available water. Because of the
use (Falkenmark and Rockstrom, 2006; Hoekstra et al., mismatch between the natural hydrological cycle and
2011). Water withdrawal is defined as the amount of human needs for water, infrastructure is often built to
water withdrawn from surface water or groundwater for help societies manage water; for example, many times
some human use. Some of this water may be returned reservoirs are constructed to store water during wet
to surface water or groundwater after use. Water con- periods for use during dry periods. Similarly, ground-
sumption is typically defined as the amount of water water is often used in the HKH region when surface
withdrawn from surface water or groundwater that is supplies are insufficient because of seasonality of water
not returned to the system, usually because it is lost to flows or short-term droughts.
evapotranspiration, incorporated into a final product, Water must also be of sufficient quality to be of
or contaminated too badly to be reused. use, and different water uses require different quali-
"Green water" use is defined as the amount of ties. Some industrial and urban water uses require
rainwater used by natural vegetation, land cover, and high-quality waters; agriculture often uses lower qual-
agricultural production primarily through rain-fed ity waters. When water is highly polluted because of
crops (Hoekstra et al., 2011). Both green water and high salinity or concentrations of human or industrial
blue water (irrigation water) are used for agricultural wastes, water quality can become the limiting factor for
production in the HKH region. If agricultural devel- water availability--in some parts of the HKH region,
opment replaces natural land cover with crops with a pollution may reduce overall water availability. Some-
higher level of evapotranspiration than natural vegeta- times "gray water" use is also measured. In the water
TABLE 3.5 Population Growth Rates, by Country, 2010-2050
2010-2015 2015-2020 2020-2025 2025-2030 2030-2035 2035-2040 2040-2045 2045-2050
Bangladesh 6.47% 5.65% 4.75% 3.81% 2.88% 2.05% 1.26% 0.52%
Bhutan 7.99% 5.74% 4.58% 3.69% 2.78% 2.06% 1.38% 0.63%
India 6.83% 6.01% 5.19% 4.42% 3.70% 2.99% 2.30% 1.65%
Nepal 8.75% 7.93% 7.08% 6.08% 5.09% 4.22% 3.45% 2.74%
Pakistan 9.25% 8.29% 7.42% 6.27% 5.27% 4.45% 3.67% 2.86%
SOURCE: Based on data from United Nations (2011b).
OCR for page 54
54 HIMALAYAN GLACIERS: CLIMATE CHANGE, WATER RESOURCES, AND WATER SECURITY
footprint system of water use accounting, gray water is use data are also available for China, but they are not
defined as the amount of water needed to safely dilute considered here except in the context of the portions
a contaminant or problematic compound to a con- of the HKH watersheds shared by China.
centration at which the water will be usable for some One rough measure of water supply is the per-
purpose, which is increasingly important at a river basin capita availability of water (the total average renewable
scale (Hoekstra et al., 2011; note that this is a different water supply of a region divided by the population of
concept from municipal gray water, or sullage). that region). Another is the ratio of water withdraw-
Any alterations to the water quantity or quality also als (as an indicator of demand for water) to renewable
have the potential to negatively affect freshwater biodi- water availability (as an indicator of water supply).
versity or the natural ecosystem services they provide. Of the five countries, Bhutan has the largest supply
Often, a certain minimum environmental flow is calcu- of water, both relative to water withdrawals and on a
lated for a watershed and its watercourses, which if left per-capita basis. Total internal renewable water supply
in surface water and groundwater will be sufficient to is 78 billion m3 yr-1, and because Bhutan is located
maintain freshwater biodiversity and crucial ecosystem high in the Himalayas, there is no significant flow into
processes (Poff et al., 2010). Necessary environmental the country from elsewhere. Total per-capita available
flows vary significantly between basins depending on water remains high but has fallen slightly over time
the hydrology and ecology. with population, from 174,000 m3 person-1 yr-1 in 1992
to 109,000 m3 person-1 yr-1 in 2009 as its population
Key Trends in Water Use has grown. Total water withdrawals were 0.34 billion
m3 yr-1 in 2009, or around 470 m3 person-1 yr-1.
In general, the Committee found water use is As a downstream nation, Bangladesh has greater
greater relative to natural runoff in the Indus Basin than reliance on external water supplies relative to water
in the Ganges/Brahmaputra Basin, consistent with withdrawals (Figure 3.2). Total internal renewable
the findings of other studies (e.g., UNEP, 2008). At a water supply is about 100 billion m3 yr-1, supplemented
national level, water use relative to availability is lowest by another 1.1 trillion m3 yr-1 of water that flows in
in Bhutan and Nepal, intermediate in Bangladesh and from outside the country. Total per-capita available
India, and greatest in Pakistan. water has fallen from approximately 10,000 m3 person-1
yr-1 in 1992 to 7,700 m3 person-1 yr-1 in 2008. Total
National-Level Water Use Statistics water withdrawals were 36 billion m3 yr-1 in 2008, or
around 220 m3 person-1 yr-1.
Comprehensive and consistent data on water avail- India's water withdrawals are closer to water avail-
ability and water use are not available for the HKH ability than most other countries in the region (Figure
region, or most other regions of the world (Gleick, 3.2). Total internal renewable water supply is 1,400
2011). One of the primary sources of data for gross billion m3 yr-1, supplemented by another 640 billion
water availability and withdrawals is the Aquastat data- m3 yr-1 of water that flows in from outside the country.
base maintained by the Food and Agriculture Organi- Total per-capita available water has fallen from 2,100
zation of the United Nations (FAO, 2011). Aquastat m3person-1 yr-1 in 1992 to 1,600 m3person-1 yr-1 in
data come from a variety of sources, estimates, and 2008. Total water withdrawals are increasing from 500
surveys, including national-level estimates submitted billion m3 yr-1 in 1990 to 760 billion m3 yr-1 in 2010,
by national governments. Because of the lack of water or from around 560 m3 person-1yr-1 in 1990 to 640
availability and water use data, the Aquastat database m3 person-1 yr-1 in 2010. India contains several large
contains the most widely used estimates of these quanti- watersheds and these national average figures hide sig-
ties and is used here to assess broad patterns and trends, nificant regional variations. In some basins, total water
but should not be considered scientifically rigorous. As demands are approaching, or may have reached, the
discussed earlier in this chapter, Bangladesh, Bhutan, limits of renewable water availability. In other basins,
India, Nepal, and Pakistan have substantial portions of water use already depends on nonrenewable extraction
their area contained within the watersheds that make of groundwater resources, which is unsustainable in
up the study area. National-level water availability and the long run.
OCR for page 55
HUMAN GEOGRAPHY AND WATER RESOURCES 55
FIGURE 3.2 Available per-capita water and per-capita water withdrawal for countries in the study region. Countries are arranged
from greater relative water stress (left) to less relative water stress (right). Note the logarithmic scale on the y-axis. Available per-capita
water is shown as a stacked bar-chart for two points in time, showing the portion of available water that originates within a country
(internal, black) or that originates in headwaters located in another country (external, gray). The per-capita withdrawal information is
shown as a white triangle for the most current time point. PAK= Pakistan, IND= India, BAN= Bangladesh, NEP= Nepal, and BHU= Bhu-
tan. For Nepal, per-capita withdrawal information was available only for the year 2002. For India, per-capita withdrawal information
was linear interpolated between the years 2002 and 2010, to estimate the value in 2008. SOURCE: Based on data from FAO (2011).
Nepal has a substantial supply of water in both capita basis have fallen from around 1,300 m3 person-1
absolute terms and relative to water withdrawals, on a yr-1 in 1990 to 1,000 m3 person-1 yr-1 in 2008. Pakistan
per-capita basis (Figure 3.2). Total internal renewable would not be able to meet its water withdrawal demand
water supply is about 200 billion m3 yr-1, supplemented without external water resources, primarily from rivers
by another 12 billion m3 yr-1 of water that flows in from that flow from India into the Indus, as allocated by the
outside the country. Total per-capita available water has Indus Waters Treaty.
fallen from approximately 10,500 m3person-1 yr-1 in National water availability and use data for China
1992 to 7,300 m3 person-1 yr-1 in 2008 because of popu- are uninformative for this study, because they are
lation growth. Total water withdrawals were 10 billion dominated by regions of the country outside the
m3 yr-1 in 2000, or around 390 m3 person-1 yr-1 in 2002. HKH study area. Nevertheless, China is the upstream
Pakistan's internal water supplies are very limited nation on major watersheds of the HKH region; the
relative to water withdrawals, on a per-capita basis Tibetan Plateau encompasses the origins of the Ganges
(Figure 3.2). Total internal renewable water supply is (whose headwaters are mostly in India), the Brahma-
only 55 billion m3 yr-1, supplemented by another 180 putra (which joins the Ganges in Bangladesh), and the
billion m3 yr-1 of water that flows in from outside the Indus Rivers. Thus, China can influence the long-term
country. Population growth has reduced total per-capita regional management of these rivers. In addition, the
available water, which has fallen from 1,900 m3 person-1 Chinese government has announced plans for "leap-
yr-1 in 1992 to 1,300 m3 person-1 yr-1 in 2008. Total frog development" in the Tibetan Plateau, including
water withdrawals have increased from 160 billion m3 improving the economic status of farmers and herders
yr-1 in 1990 to 180 billion m3 yr-1 in 2008, but on a per- and providing services such as education, health, and
OCR for page 56
56 HIMALAYAN GLACIERS: CLIMATE CHANGE, WATER RESOURCES, AND WATER SECURITY
social security--with the express purposes of achieving area is for increased irrigation water withdrawals to put
stability and national unity (Xinhua News, 2010). Min- increasing strain on hydrological supplies of available
ing, which requires water (see Xiang [2010] for a study water. See Box 3.1 for a historical overview of early and
of mining effects on river water quality in Tibet), and modern irrigation systems.
hydroelectric dams are part of planned development in Irrigated area in the study region is shown in Figure
the Tibetan region (Watts, 2010). In addition, Chinese 3.3. According to the Global Map of Irrigated Area
plans to divert some regional water resources from the (Siebert et al., 2007), which is nominally for around the
south to its northern regions will also play a role in year 2000, irrigation is widespread in the Indus Basin,
future regional water politics (Turner, 2011). Further with a total of 15 million ha equipped for irrigation,
analysis of how climate factors, including glacial retreat, the vast majority of which is in Pakistan. However,
may influence Chinese needs for water and Chinese the national- and basin-level data are rough estimates.
water policies is needed. According to FAO Aquastat data, Pakistan had about
16 million ha equipped for irrigation in 1990, which
Water for Irrigation had risen to 20 million ha by 2008. Total Pakistan
agricultural water withdrawal went from 150 billion
In most countries, the largest sector of water use is m3 yr-1 in 1991 to 170 billion m3 yr-1 in 2008, or from
the agricultural sector, which withdraws, and consumes 9,600 m3 ha-1 yr-1 in 1991 to 8,600 m3 ha-1 yr-1 in 2008.
through evapotranspiration, large quantities of water Another useful large-scale dataset (Hoekstra and
for irrigation. The general trend throughout the study Mekonnen, 2011) provides estimates of water con-
BOX 3.1 Early and Modern Irrigation Systems
The history of irrigated agriculture in the region goes back to development of modern submersible pumps allowed the pumping of
Harappan civilization during the Bronze Age in the greater Indus Basin groundwater from great depths. Simultaneously, small inexpensive
and adjacent areas. Early irrigators relied on shallow wells, flood inun- pumps were developed that allowed growers to lift water to irrigate small
dation canals, and simple diversions from adjacent streams to water farm acreage (Shah, 2009).
farmlands in arid and semiarid regions. With time and the advent of Again, historically water was applied through simple flood ir-
canals, surface waters could be delivered to arable lands that were less rigation technologies where fields were flooded at times of high water.
proximate to surface-water courses. Canal irrigation expanded most Flood irrigation was replaced in many parts of the world by furrow and
dramatically in South Asia during the 19th and 20th centuries. Canals basin irrigation that allowed the grower more control over the timing
also allowed irrigators some control over the timing and quantity of water and quantities of water application. Over the last 75 years of the 20th
applied to cropland. Groundwater initially became a source of irrigation century, closed conduit irrigation systems were increasingly developed
supply with the development of simple water lifting devices powered and employed. These systems, which include various types of sprinklers
by humans and animals. The use of groundwater for irrigation allowed and, later, drip and sprinkler irrigation systems, allow water to be ap-
lands to be irrigated in dry seasons during drought periods when surface plied with great precision. These systems are particularly well adapted
supplies were diminished or absent altogether. to irrigate loose agricultural soils where control of infiltration rates is
The Persians were early groundwater innovators who developed very important in determining irrigation efficiency, and have substantial
the Qanat or Karez system of tapping and conveying groundwater. This additional potential. By contrast, surface application systems such as
system required the drilling of multiple wells into alluvial water-bearing furrows and basins are best suited for farming operations on tight soils
formations in foothill environments and then constructing a tunnel that where infiltration rates are low and tend to be more constant, particularly
conveyed water underground to elaborate surface-water distribution where precision land leveling and watercourse improvements were
systems on the plains. This clever system, which is still used in some adopted. Modern irrigation technology has resulted in more extensive
locations in the Middle East and South Asia (Mustafa, 2011), permitted and more efficient irrigation, particularly when linked with institutional
the extraction of groundwater by gravity and avoided the need to lift the and management reforms. Yet, in many instances, such as South Asia,
water from the wells. This system required a high level of community it has increased the pressure on both surface water and groundwater
cohesion to operate effectively. sources and even threatened the long-term sustainability of the basic
Much later electrical and diesel pumps were developed that al- water resource (e.g., because of soil and water salinity; CAST, 1988; cf.
lowed water to be lifted from wells in substantial quantities. Early pumps extensive publications on irrigation in South Asia by the International
were limited in the depth from which they could lift water but the later Water Management Institute).
OCR for page 57
HUMAN GEOGRAPHY AND WATER RESOURCES 57
sumption by basin for irrigation of different crops. unreasonable, therefore, to consider further ground-
Around 120 billion m3 yr-1 of irrigation water were esti- water development and use as a potential response to
mated to be consumed through evapotranspiration in surface-water shortfalls that might ultimately occur
the Indus. Total consumptive water use for irrigation is because of changes in the rates and magnitudes of
approximately 100 billion m3 yr-1 for the Ganges, much glacial melt.
greater than the 1.4 billion m3 yr-1 for the Brahmapu- Today, groundwater use is the focus of what Shah
tra. More than a third of irrigation water consumed is (2009) characterizes as a "colossal anarchy." The need
used for wheat, with rice taking just under a third of to feed a growing population and agricultural markets
the remaining water. Compared with the other basins has resulted in intense pressure to farm arable land
in the study area, a relatively large amount of irrigated as extensively and intensively as possible. In India,
water consumption in the Indus Basin is for cotton pro- this has caused a transition away from the established
duction, along with rice, sugarcane, and wheat. In the large-scale irrigated agriculture that relied on water
Brahmaputra Basin, by comparison, around 75 percent deliveries through canals and irrigation systems that
of irrigated water was used to grow rice. were managed in a more centralized bureaucratic way.
Irrigation is very common in the Ganges and The combination of land scarcity, the availability of
less common in the Brahmaputra Basin. The overall small, inexpensive pumps that can be used to extract
Ganges/Brahmaputra Basin supported 29 million ha groundwater, and subsidized electricity has led to a
of area equipped for irrigation around the year 2000, situation in which approximately 22 million farmers
primarily in India but also in Bangladesh. Nepal has in India, for example, are pumping groundwater in an
much more limited irrigated area because of its climate individualistically competitive fashion to intensively
and topography. According to Aquastat data, India had irrigate relatively small plots of land. The resultant
a total of 62 million ha equipped for irrigation in 2001, levels of groundwater overdraft are significant. Thus,
which had risen to 66 million ha by 2008. Total Indian for example, Rodell et al. (2009) estimated that between
agricultural water withdrawal increased from 560 bil- 2002 and 2008, groundwater extraction in three Indian
lion m3 yr-1 in 2000 to 690 billion m3 yr-1 in 2008, or states (Rajasthan, Punjab, and Haryana) exceeded
from 9,000 m3 ha-1 yr-1 in 2000 to 10,400 m3 ha-1 yr-1 recharge by 18 billion m3 yr-1 (Rodell et al., 2009). This
in 2008. Bangladesh had 5 million ha equipped for estimate is consistent with the empirical data referred
irrigation in 2008. Total Bangladeshi agricultural water to in the previous chapter that documents the magni-
withdrawal was 32 billion m3 yr-1 in 2008, or around tude of groundwater overdraft. It is clear that current
6,300 m3 ha-1 yr-1. Assuming the average Indian appli- levels of groundwater overdraft cannot be sustained and
cation rate of 9,000 m3 ha-1 yr-1 in 2000 is accurate for efforts to "tame the anarchy" have not been especially
the irrigated area in the Ganges/Brahmaputra Basin, successful to date (Shah, 2009).
total withdrawals in 2000 were 260 billion m3 yr-1. Groundwater is managed in accord with the dic-
There is very little irrigation in the upstream tates of irrigated agriculture. As in other parts of the
nations of the Himalayan plateau region (Figure 3.3). world, the price of water includes no scarcity value
The only exception seems to be near Koko Nor (Qing- for the water itself and consists solely of the costs of
hai) Lake in the Tibetan Plateau and the far northern extraction. Even extractive costs are at levels less than
portions of the study area, which includes parts of their true value (or cost) because the cost of the energy
northwest Gansu Province of China. Because this small has been subsidized in various ways by governments.
amount of irrigated area is dwarfed by irrigated areas This results in an array of water prices that significantly
elsewhere in China, the Aquastat statistics on overall understate the real value of the water, sending, in turn,
irrigation in China are not informative. false signals to consumers about its relative scarcity.
Groundwater and surface water are frequently That is, the prevailing prices signal irrigators that water
substitutes for each other. There are many historical is more plentiful than it is in fact. The consequence
examples in which emerging shortages in surface- is that cropping patterns are not always appropriate
water supplies have been offset by increased reli- and the quantities of water applied are more than they
ance on groundwater and vice versa. It would not be would be if the water was appropriately priced.
OCR for page 58
58 HIMALAYAN GLACIERS: CLIMATE CHANGE, WATER RESOURCES, AND WATER SECURITY
FIGURE 3.3 Fraction of the land equipped for irrigation in the HKH region. Irrigation is widespread in both the Indus and Ganges/
Brahmaputra basins. A relatively large amount of irrigated water consumption in the Indus Basin is for cotton production. In the
Brahmaputra Basin, by comparison, irrigation water use is dominated by rice production, while in the Ganges Basin, irrigated water
is used primarily for wheat production.
At least two factors militate against bringing extrac- with groundwater to poverty (Shah, 2009). Thus, India's
tions into some reasonable balance with recharge. First, groundwater economy is very likely to become a source
the sheer numbers of extractors mean that the transac- of additional demands for surface water as elements
tion costs associated with any of the conventional forms of the groundwater resource become economically
of groundwater regulation such as pump taxes (prices) exhausted. Indeed, the consequences of such economic
and supervised pumping quotas would be enormous exhaustion are thought to be so severe that a contested
and would outweigh any likely benefits of such regula- plan has been proposed to link the Himalayan rivers
tion. Second, groundwater extractors could collectively with the peninsular rivers of India, which would allow
represent a significant political force that would resist the import of some 200 km3 annually to southern and
any attempts by government to require or induce western India to offset the effects of overdraft (Shah,
reductions in the quantities of groundwater extracted 2009; Supreme Court of India, 2012; cf. Iyer, 2012).
or energy subsidized. An additional and potentially
problematic feature of this situation is that successful Water Use in Other Sectors
efforts at groundwater regulation, whether by pricing,
pump quotas and other means such as the control of In most countries, the sector that makes the most
complementary inputs, would condemn large numbers withdrawals after agriculture is the municipal and
of people who currently survive by irrigating small plots industrial sector. In some regions, withdrawals for
OCR for page 59
HUMAN GEOGRAPHY AND WATER RESOURCES 59
electric power production and cooling are predominant, which considered only urban agglomerations of more
though urban withdrawals are increasingly significant. than 50,000 people. This dataset estimates 41.5 mil-
Figure 3.4 shows the location of the major cities within lion urban dwellers in Pakistan in 2000. Dividing the
the study area. Most major cities in Pakistan are within Aquastat value for municipal withdrawal in 2000 of 6.4
the Indus Basin or draw their water from the Indus billion m3 yr-1 by just this urban population, that is a use
(e.g., Karachi). Kabul, Afghanistan, is also in the upper rate of 154.2 m3 urbanite-1 yr-1. The GRUMP database
headwaters of the basin. Aquastat data estimate 2.5 bil- shows 34.3 million urban dwellers in the Indus Basin,
lion m3 yr-1 of withdrawals for municipal purposes in which with the above use rate would imply 5.3 billion
Pakistan in 1991, rising to 9.7 billion m3 yr-1 in 2009, m3 yr-1 of municipal withdrawals in the Indus Basin in
or from around 20 m3 person-1 yr-1 in 1992 to 54 m3 2000. This approach, however, ignores cities that are
person-1 yr-1 in 2008. However, the per-capita statis- outside the Indus Basin but draw water from it through
tics from Aquastat divide municipal water use by the canals (cf. McDonald et al., 2011b).
total population of the country, not just that of urban The majority of the 87.9 million urban dwellers
dwellers. in cities > 50,000 in the Ganges Basin in 2000 were in
Another dataset, the Global Rural/Urban Map- India (69.6 million), with some in Nepal (2.6 million)
ping Project (GRUMP) database (CIESIN, 2004), or Bangladesh (15.6 million). Total urban population
maps cities for the region. The version of this dataset in India in 2000 was 234.9 million in cities > 50,000,
developed for McDonald et al. (2011a) was used, and Aquastat lists total municipal withdrawals in 2000
FIGURE 3.4 Major urban areas in the HKH region. Urban water withdrawals are increasingly significant, and the locations of urban
areas provide a rough estimate of the locations of most municipal and industrial water withdrawals.
OCR for page 62
62 HIMALAYAN GLACIERS: CLIMATE CHANGE, WATER RESOURCES, AND WATER SECURITY
tive fashion; the Committee did not develop quantita- ments in improving irrigation efficiency. Scenarios
tive scenarios of how hydrological flows will change in of future agricultural water use developed by Archer
each of the basins in response to climate change. The et al. (2010) are similar, and the authors stressed the
potential changes in water supply discussed earlier in necessity of increased water storage to allow for a
this chapter could also affect water use. continued increase in agricultural withdrawals. More-
over, agricultural withdrawal and consumption could
Water for Irrigation be significantly reduced if Pakistan increased the
productivity of agricultural water use, which would
Trends in irrigation water use vary throughout the permit them to expand production without substantial
region. In some countries, irrigated crop area has been increases in demand for water, through on-farm and
increasing, which increases water use. At the same time, basin efficiency improvements, changes in irrigation
in some countries average irrigation rates (m3 ha-1 yr-1) technology and management, changes in crop types,
have been decreasing because of more efficient appli- or other practices.
cations of irrigation water or changes in the kinds of The overall Ganges/Brahmaputra Basin had 29
crops produced. Future trends in irrigation water use million ha of area equipped for irrigation in 2000
are difficult to predict and depend on (among other (Siebert et al., 2007), primarily in India and to a lesser
things) changes in farming practices, government poli- extent Bangladesh. Nepal and Bhutan have much more
cies toward irrigation, and the magnitude and direction limited irrigated area because of their climate and
of the effect of climate change on evapotranspirative topography, a trend likely to persist into the future.
demand of crops. India's irrigated area increased by 0.9 percent annually
In the Indus Basin, approximately 15 million ha between 2001 and 2008, with some of the increase
of cropland was equipped for irrigation in 2000 (Sie- in the Ganges Basin and some of it elsewhere in the
bert et al., 2007), mostly in Pakistan. Aquastat (FAO, country. Over the same time period, India's irrigation
2011) statistics show that between 1990 and 2008, area rate has increased by around 2 percent annually, from
equipped for irrigation in Pakistan increased by 1.3 1995 to 2008, Bangladesh's irrigated area, which is in
percent annually, up to 20 million ha, the vast majority both the Ganges and Brahmaputra basins, increased by
of which is in the Indus Basin. If this trend continues, 2.3 percent annually. Time-series data for Bangladesh
by 2030, Pakistan would have 25 million ha and by on irrigation rate are unavailable, although in 2008
2050 there would be 30 million ha. At the same time, it appeared to be lower than Indian rates, at around
between 1990 and 2008, the irrigation rate fell by 0.5 6,300 m3 ha-1 yr-1. Other pertinent data reveal that
percent annually, to 8,600 m3 ha-1 yr-1. Assuming this about 75 percent of total land cultivated in Bangladesh
trend continues, by 2030, Pakistan's irrigation rate is irrigated by groundwater (Zahid and Ahmed, 2006)
would fall to 7,500 m3 ha-1 yr-1 and by 2050 would and that groundwater has been decreasing (Shamsud-
reach 6,500 m3 ha-1 yr-1. The net result of such a sce- duha et al., 2009). Thus, irrigation in Bangladesh has
nario for Pakistan would be an increase in agricultural been increasing, with noticeable effects on groundwater
withdrawals from 170 billion m3 yr-1 in 2008 to 190 depletion.
billion m3 yr-1 in 2030 and 195 billion m3 yr-1 in 2050. Because the vast majority of irrigated area in the
Assuming that in the future a similar fraction of water Ganges/Brahmaputra is in India, changes in irrigation
withdrawals is consumed, water consumption under practices in India will drive changes in the Ganges/
such a scenario would increase from around 120 billion Brahmaputra area. If the irrigated area in the overall
m3 yr-1 in 2000 to 128 billion m3 yr-1 in 2030 and 132 Ganges/Brahmaputra continues expanding at the same
billion m3 yr-1 in 2050. rate as irrigated area is currently expanding in India,
Whether such a scenario would be feasible depends by 2030 there would be 39 million ha of area equipped
on whether there is enough water available to meet for irrigation and by 2050 some 48 million ha. It is not
this increased need, whether there is adequate arable clear whether there is enough room in the crowded
land to allow continued expansion of irrigated area, Ganges basin for such a continued expansion, nor is it
and whether Pakistan can make the necessary invest- clear that there is sufficient water. If India's irrigation
OCR for page 63
HUMAN GEOGRAPHY AND WATER RESOURCES 63
rate remains at 2008 levels of around 10,400 m3 ha-1 people) by 2050. Assuming the urban use rate of water
yr-1, such a scenario would increase agricultural water stays the same, expected population growth implies an
withdrawals in the Ganges/Brahmaputra from 260 bil- increase in municipal water use to 13 billion m3 yr-1 of
lion m3 yr-1 in 2000 to 400 billion m3 yr-1 in 2030 and municipal withdrawals in the Indus Basin in 2030 and
nearly 500 billion m3 yr-1 in 2050. It seems unlikely 22 billion m3 yr-1 of municipal withdrawals in the Indus
that there is enough water in the Ganges to support Basin in 2050.
this level of withdrawal, particularly in the dry months In 2000, there were 88 million urban dwellers in
(see discussion below). cities > 50,000 in the Ganges/Brahmaputra Basin,
This scenario for the Ganges/Brahmaputra is primarily in India (70 million) and to a lesser extent
similar to one developed by the 2030 Water Resources Bangladesh (16 million) (CIESIN, 2004). India had
Group (2009), which predicted that, if current trends an urban use rate of 179 m3 urbanite-1 yr-1, and Ban-
continue, by 2030 Indian agricultural withdrawals gladesh had an urban use rate of 155 m3 urbanite-1 yr-1.
would have nearly doubled from current levels. This For India, urban population is projected to increase by
report also notes that changes in the agricultural sector's 2.4 percent per year between 2000 and 2030, or by 1.7
water use also represents the most cost-effective way percent per year between 2000 and 2050. Bangladesh
to reduce India's water withdrawals, especially imple- is forecast to have similarly rapid urban population
mentation of measures that increase yields from India's growth, increasing by 3.1 percent per year between
cropland without increasing water applied as irrigation. 2000 and 2030, or by 2.1 percent per year between 2000
Similarly, Cai et al. (2010) found that if less productive and 2050. Assuming these urban population growth
areas in India were to achieve the same water productiv- rates, and that urban use rate stays the same, India's
ity as more productive areas, agricultural withdrawals municipal withdrawals from the Ganges/Brahmaputra
could be reduced by 31 percent without reducing agri- Basin would grow from 12 billion m3 yr-1 in 2000 to
cultural production. 26 billion m3 yr-1 in 2030 and 29 billion m3 yr-1 in
2050. Similarly, Bangladesh's municipal withdrawals
Municipal Water Use from this basin would grow from just over 2 billion m3
yr-1 in 2000 to 6 billion m3 yr-1 in 2030 and 7 billion
Trends in the municipal sector are consistent across m3 yr-1 in 2050. Municipal withdrawals for Nepal and
countries, with an increasing urban population result- Bhutan will likely increase as well, driven by increases
ing in an increase in municipal withdrawals. Trends in in urban population in these countries, although their
the use rate (m3 urbanite-1 yr-1) are generally not avail- municipal withdrawals will continue to be a very
able as time series, although economic development is small proportion of the municipal withdrawals in the
likely to increase this use rate over time. Ganges/Brahmaputra Basin.
In 2000, the GRUMP database (CIESIN, 2004) This scenario of growth in municipal water demand
shows 34 million urban dwellers in the Indus Basin in the Ganges/Brahmaputra Basin appears consistent
(cities > 50,000 people). The vast majority of these with the scenarios developed for India by the 2030
urbanites are in Pakistan, where the average urban Water Resources Group (2009). That report predicted
use rate was around 150 m3 urbanite-1 yr-1, a relatively municipal demand would double from 2000 to 2030,
high rate, which with the above use rate would imply a slightly slower rate of growth than in the Commit-
over 5 billion m3 yr-1 of municipal withdrawals in the tee's scenario of growth developed specifically for the
Indus Basin in 2000. For Pakistan as a whole, urban Ganges.
population is projected to increase by 3.1 percent per
year between 2000 and 2030, or by 2.8 percent per year Industrial Water Use
between 2000 and 2050 (United Nations, 2011b). If
this rate of urban population growth holds for the Indus Industrial water use appears likely to increase over
Basin as a whole, population might grow to nearly time, driven by increases in population and economic
85 million urban dwellers (cities > 50,000 people) by development. In the Aquastat database, there is little
2030 and 140 million urban dwellers (cities > 50,000 consistent trend in industrial water use per capita, with
OCR for page 64
64 HIMALAYAN GLACIERS: CLIMATE CHANGE, WATER RESOURCES, AND WATER SECURITY
some countries increasing and some countries decreas- water scarcity will change with increases in population
ing. However, even if water use per capita stays constant and water use as well as with climate change. Because
at 2008 levels, it appears likely industrial water use quantitative scenarios of how the hydrological cycle will
will continue to rise because of fast rate of population be affected by climate change were beyond the scope of
growth in many of these countries. this report, most of the discussion of climate change is
The majority of Pakistan's 1.4 billion m3 yr-1 of narrative, describing the likely direction of change.
industrial withdrawals in 2008 was likely from the As noted earlier, the simplest way to define physi-
Indus Basin, and if industrial water use per capita stays cal water scarcity is to take the amount of water in a
the same might rise to 2.3 billion m3 yr-1 in 2030 and region and divide by the population. One common set
3 billion m3 yr-1 in 2050. India's industrial withdrawals of thresholds defines regions with more than 1,700
in the Indus are unknown, but are likely smaller than m 3 person -1 yr -1 as "water sufficient," while those
Pakistan's, because few major Indian cities are located below this threshold have some degree of water stress
in the Indus Basin. (<1,700 m3 person-1 yr-1), chronic scarcity (<1,000 m3
Trends in India's industrial withdrawals from the person-1 yr-1), or absolute scarcity (<500 m3 person-1
Ganges/Brahmaputra are unknown, but are likely yr-1) (Falkenmark, 1989; Falkenmark and Lindh, 1974;
increasing over time. One study by the 2030 Water Falkenmark and Widstrand, 1992; Falkenmark et al.,
Resources Group (2009) suggests that industrial with- 1989). Using this metric, with population growth
drawals for all of India will quadruple, reaching 196 (ignoring potential changes in water availability)
billion m3 yr-1 in 2030. A large portion of Bangladesh's Pakistan will move from water stress in 2000 (1,400
0.8 billion m3 yr-1 of industrial withdrawal in 2008 m3 person-1 yr-1) to chronic scarcity in 2030 (900 m3
was taken from the Ganges/Brahmaputra Basin and, person-1 yr-1) and 2050 (700 m3 person-1 yr-1), even
if industrial water use per capita stays the same, might without factoring in climatic changes to regional
rise to 1.1 billion m3 yr-1 in 2030 and 1.2 billion m3 yr-1 hydrology. Any reductions in flow in the Indus caused
in 2050. Similarly, Nepal's industrial withdrawals of 0.4 by climate change would further intensify this scarcity.
billion m3 yr-1 in 2000 are all taken from the Ganges The next driest country by this metric is India, which
Basin, and if industrial water use per capita stays the stays classified as water stressed but moves from 1,600
same might rise to 0.6 billion m3 yr-1 in 2030 and 0.7 m3 person-1 yr-1 in 2009 to 1,300 m3 person-1 yr-1 in
billion m3 yr-1 in 2050. Bhutan uses a relatively trivial 2030 and 1,200 m3 person-1 yr-1 in 2050. By this simple
amount of water for industrial purposes, a trend that is measure, and ignoring potential changes in water avail-
likely to continue. ability, Bangladesh, Bhutan, and Nepal remain classed
as water sufficient through 2050.
Trends in Water Scarcity Another way to define physical scarcity is the ratio
of water use to water availability. By this metric, and
As discussed in Chapter 3, we primarily pre sent ignoring potential changes to water availability, the
simple metrics of physical water scarcity. This approach Indus Basin seems the most likely of any of the study
is driven by the limited data available for more sophisti- area basins to face problems of water scarcity (Figure
cated measures that take into account, for example, eco- 3.6). Significant increases in irrigation water use in this
nomic water scarcity or water quality issues. However, basin, particularly during the dry months of November
we stress that these other issues may be important and to March, may result in essentially all flow in these
deserve future study. Levels of water stress in the future months being used for irrigation. Increased irrigation
will also be affected by adjustments to human behavior water use in the Ganges, particularly in the dry period
or technological interventions to make existing water of November to May, may likewise result in essentially
use more efficient, both of which are difficult to predict. all flow in these months being used for irrigation
Even without climate change affecting water avail- (Figure 3.7). One potential response by policy mak-
ability in the study area, many countries would have a ers would be to attempt to increase storage during the
significant challenge providing enough water to meet monsoon season so that water would be available for
their needs under traditional projections. In this sec- irrigation during the dry season. Even with increases in
tion, the Committee explores how some metrics of irrigation water use by Bangladesh, the Brahmaputra
OCR for page 65
HUMAN GEOGRAPHY AND WATER RESOURCES 65
FIGURE 3.6 Natural runoff (solid line) and blue water consumed (dashed line) per month for the Brahmaputra. Note that the y-axis
is a log scale. The Brahmaputra has very little water scarcity, except in February and March, although water consumption still does
not exceed natural runoff during those months. The large spike in natural runoff in the period June to September corresponds to the
monsoon period. SOURCE: Based on data from Hoekstra and Mekonnen (2011).
Basin seems less likely to be water stressed according The picture that emerges is nevertheless one in
to this metric, except for a brief dry period in February which water scarcity, be it generalized or seasonal, will
and March (Figure 3.6). intensify in the coming decades. Climate change will
also influence the extent and severity of intensifying
FIGURE 3.7 Natural run-off (solid line) and blue water (dashed line) consumed per month for the Ganges. The Ganges has very
little water scarcity, except in February and March, when water consumption exceeds natural runoff. The large spike in natural runoff
in August corresponds to the monsoon period. SOURCE: Based on data from Hoekstra and Mekonnen (2011).
OCR for page 66
66 HIMALAYAN GLACIERS: CLIMATE CHANGE, WATER RESOURCES, AND WATER SECURITY
scarcity. It follows, then, that one means of addressing TABLE 3.6 Share of Population with Access to Improved
potential changes in hydrological circumstances that Drinking Water and Sanitation, by Country
are uncertain is to ensure that current water manage- Improved Drinking Water Improved Sanitation
ment practices are as effective and equitable as possible. Urban Rural Total Urban Rural Total
This means making all efforts to increase and maintain Afghanistan 78 39 48 60 30 37
the productivity of water that is currently available. Bangladesh 85 78 80 56 52 53
Such productivity increases need to be sought for both
Bhutan 99 88 92 87 54 65
consumptive and in-stream uses. Thus, for example,
China 98 82 89 58 52 55
employment of more rational water pricing practices
India 96 84 88 54 21 31
and the development of flexible schemes of water
Nepal 93 87 88 51 27 31
allocation that will allow droughts and unanticipated
Pakistan 95 87 90 72 29 45
shortfalls to be managed in both a timely and effec-
tive way could strengthen the capacity of the region to SOURCE: Data from WHO/UNICEF (2010).
manage its water resources more effectively in the face
of climate change and other hydrological uncertainties. and sanitation, even when stratified by urban and rural
residence, tend to mask considerable spatial variation in
CLEAN WATER AND SANITATION ACCESS access. Data from the nationally representative Demo-
graphic and Health Surveys (DHS),5 for example,
A basic measure of water development and condi- suggest that there is greater variation in access to clean
tions is access to improved drinking water and sanita- water and sanitation in rural districts than urban dis-
tion systems, as measured by the United Nations on tricts. It is possible, in principle, to use these data to
a regular basis. This measure forms the standard by create district-level mappings of access to clean water
which the water-related Millennium Development and sanitation. This could provide finer-grained insight
Goals were set. Political and social stability is affected into the geographic distribution of water-related need
by the societal capacity to cope with and adapt to large- and vulnerability, including by river basin and proxim-
and small-scale changes in water availability that may ity to the Himalayas.
result from glacial retreat and other impacts of climate
change on the hydrological system. This societal capac-
MEASURING WATER SCARCITY
ity, often called vulnerability or resilience, depends on
conditions that promote human well-being generally. With the preceding analysis in mind, it is not sur-
The water-related aspects commonly measured include prising that there are many different ways to measure
water availability or scarcity (discussed in the next sec- water scarcity. Water scarcity can occur when problems
tion) and clean water and sanitation, which are impor- of water quantity, water quality, or timing mean there
tant for human health and general well-being. is not enough water to meet people's wants. Scarcity in
Countries in Africa have the most serious problems the physical sense is often defined in terms of arbitrary
in terms of the fraction of population without access but useful criteria such as those discussed in the next
to these basic water services, but Asia has the largest paragraph. Economic scarcity is customarily defined
absolute number of people without access (hundreds in terms of the cost of making water available and
of millions), with a wide divergence among countries a willingness to pay. One significant manifestation
and within countries. Table 3.6 shows the fraction of of economic scarcity is the economic exhaustion of
the populations in countries of the region with access groundwater, which contrasts with physical exhaustion,
to "improved drinking" water systems and "improved as explained in Box 3.2. In this section, we focus on
sanitation" systems, as of 2008 (WHO/UNICEF, simple measures of physical water scarcity, primarily
2010). As these data show, urban dwellers are typically because they are easy to estimate from available data.
more reliably served than rural dwellers, and access
to water is typically higher than access to sanitation. 5 Data available at http://www.measuredhs.com/data/available-
However, national-level estimates of improved water datasets.cfm.
OCR for page 67
HUMAN GEOGRAPHY AND WATER RESOURCES 67
yr-1), chronic scarci ty (<1,000 m3 person-1 yr-1), or
BOX 3.2 Economic absolute scarcity (<500 m3 person-1 yr-1). By this simple
Exhaustion 0f Groundwater measure, Bangladesh, Bhutan, and Nepal are classed as
Groundwater is an important element of hydrological sys- water sufficient, and Pakistan and India are classed as
tems throughout the world. It is known to be a significant, if not water stressed. As noted above, these national averages
completely understood, part of the hydrology of the Himalayas, hide important regional differences. Additionally, the
the Ganges Plain to the south, and the southern Peninsula of India
thresholds are somewhat arbitrary, and this measure
(Bookhagen, 2012; Shah, 2009). Over time, extractions of water
from an aquifer must be roughly equal to recharge if the aquifer is
of water scarcity does not account for water that flows
to remain economically viable. Overdraft is the situation in which across a border and it ignores different uses of water in
extractions exceed recharge. Overdraft itself is not problematic different climates.
as long as periods of intermittent overdraft are punctuated with Another common, but more descriptive, way to
periods in which recharge exceeds extractions and the aquifer consider physical water scarcity is to look at the ratio
recovers. Over such periods of time the aquifer is in equilibrium.
of water withdrawals or consumption to total water
Circumstances characterized by persistent overdraft are not sus-
tainable in the sense that extraction cannot be economically viable
available, which is defined as natural streamflow by
indefinitely. Where extractions are consistently greater by volume Hoekstra and Mekonnen (2011). Figure 3.6 shows
than recharge, the water table falls and the elevation from which estimates of natural runoff and water consumption for
water must be extracted grows. the Brahmaputra basin, on a monthly time step. This
The costs of groundwater extraction include the costs of river has very little water scarcity, except in February
needed energy and those costs are highly sensitive to the depths
and March, and even then, water consumption does not
from which the groundwater must be pumped. As the water table
is drawn down through overdraft the costs of extraction rise. Ulti-
exceed natural runoff. The large spike in water available
mately, these costs rise to the point where it is no longer economi- in the period June to September corresponds to the
cally feasible to continue pumping and the extractor or extractors monsoon period of the year.
in question cease to pump. In some instances this will allow the The Ganges basin (Figure 3.7) has a similar annual
aquifer to recover as recharge then exceeds extraction. There are pattern, but water consumption exceeds natural runoff
other instances where the storage capacity of the aquifer is altered
for February and March. There is also a sharper peak in
(consolidated) or rates of recharge are very small or nonexistent,
that it is no longer economical for any extractor to withdraw water.
natural runoff in the single month of August.
At this point the aquifer is said to be economically exhausted. Eco- Finally, the Indus Basin (Figure 3.8) has a much
nomic exhaustion is not necessarily identical to physical exhaus- higher percentage of the natural runoff consumed over
tion, however, because pumping depths from which extractions the whole year than the Ganges or the Brahmaputra
are no longer economically feasible can be significantly smaller basin, with the percentage highest in the period Octo-
than the pumping depths that would prevail if all of the water in
ber to March. However, water consumption does not
the aquifer were extracted. These latter circumstances constitute
physical exhaustion (Glennon, 2002; NRC, 1997).
exceed natural runoff in any month for the Indus, in
contrast with the Ganges.
More sophisticated measures of water scarcity
are available in the literature. Sometimes measures of
Such an approach, however, should not be taken to scarcity explicitly set aside a portion of available flow as
imply that other facets of water scarcity are not also an environmental flow (EF). Sometimes issues of water
extremely important to human livelihoods. quality are also considered, which can be a limiting
Perhaps the most common metric of physical factor for many applications (McDonald et al., 2011a).
water scarcity, and certainly the simplest to calculate, Similarly, measures of water scarcity sometimes incor-
is to take the average amount of water in a region and porate information on how well water is actually deliv-
divide by the population (Falkenmark, 1989; Falken- ered to people. In many cities, for instance, a substan-
mark and Lindh, 1974; Falkenmark and Widstrand, tial fraction of people live in neighborhoods without
1992; Falkenmark et al., 1989). These indexes usually consistent access to safe drinking water, simply because
define regions with more than 1,700 m3 person-1 yr-1 infrastructure is absent (UN-HABITAT, 2006).
as water sufficient, while those below this threshold Because data are sparse, it is not clear how increased
had some degree of water stress (<1,700 m3 person-1 glacial melt will affect total runoff. However, it could
OCR for page 68
68 HIMALAYAN GLACIERS: CLIMATE CHANGE, WATER RESOURCES, AND WATER SECURITY
FIGURE 3.8 Natural runoff (solid line) and blue water consumed (dashed line) per month for the Indus. A higher percentage of
the natural runoff is consumed than for the Ganges or the Brahmaputra basin, with the percentage highest in the period October to
March. Water consumption does not exceed natural runoff in any month for the Indus. SOURCE: Based on data from Hoekstra and
Mekonnen (2011).
affect the timing of runoff, which would in turn affect of this report, this section highlights patterns in the
the ratio of water consumption to natural runoff. For relationships between climate change and water man-
example, in the Brahmaputra, if the change in runoff agement in South Asia. Institutions that focus more
due to glacial melt occurs in February and March, on disasters (e.g., devastating floods, droughts, and
there would be a larger change in the ratio. If the run- GLOFs), vis-à-vis water management more broadly,
off were to change during the monsoon peak between are addressed under the rubric of environmental secu-
June and September, there could also be issues with rity in Chapter 4.
flooding.
Increasing International Assessment
WATER MANAGEMENT, INSTITUTIONS,
AND HYDROCLIMATE CHANGE Considerable progress has been made in assess-
ing water resources implications of climate change
The water-use patterns described above are medi- in South Asia at international and national levels of
ated by institutions at multiple levels in the region -- analysis over the past decade. Some advances have come
from international to national, state, and local water about through regional intergovernmental organiza-
management, and from mountain headwaters to plains tions (IGOs) such as the South Asian Association for
and coastal environments. In addition to multiple lev- Regional Cooperation (SAARC6), whereas others stem
els of management, water institutions span a range of from multilateral donor-sponsored initiatives. Regional
subsectors from irrigation to domestic, industrial, and IGOs such as SAARC are devoting increasing atten-
environmental uses that often have separate agencies tion to climate change, extreme events, and disaster risk
housed under different ministries, and whose perspec- reduction (e.g., SAARC; cf. also Regional Integrated
tives vary on hydroclimate change. Although a full Multi-Hazard Early Warning System for Africa and
description, let alone discussion, of these complex
water management systems lies beyond the scope 6 http://saarc-sdmc.nic.in/.
OCR for page 69
HUMAN GEOGRAPHY AND WATER RESOURCES 69
Asia [RIMES],7 which is an association of country of Water Resources (2009-2011) earlier published a
hydrometeorological agency directors in the greater two-volume work that compiled Comprehensive Mission
Indian Ocean region). Water management remains Documents for a National Water Mission Under National
a sensitive topic that has historically been addressed Action Plan on Climate Change (Government of India,
through bilateral relations, although a 2012 SAARC- 2009). Following a summary of recommendations, it
Chamber of Commerce and Industry conference presented supporting documents on the current policy
dealt with climate, energy, and water, and SAARC is context of water management, surface water, ground-
increasingly active in addressing hydroclimate disaster water, and basin planning for climate change.
preparedness. Bangladesh has joint concerns about the coastal
Comparative international water resources analysis hazards of climate change, inflows from major interna-
is also advancing through the work of the South Asia tional rivers and tributaries, and domestic hydroclimate
Water Initiative which convenes countries in the region risks. To address these issues Bangladesh created an
to analyze water management issues related to climate interagency Institute of Water Modeling chaired by
change (SAWI, 2011). The World Bank has conducted the Ministry of Water Resources as a center of climate
substantial analytical studies of water management and change modeling, and a Climate Change Cell11 for
climate risk in several countries and basins in the region adaptation and mitigation programs including irriga-
(Pahuja et al., 2010; Sadoff and Rao, 2011; Yu, 2010). tion agriculture under the Ministry of Environment.
These studies are helping increase awareness, analysis, The Government of Pakistan established a Global
and cooperation. Change Impact Study Centre (GCISC) that prepared
Among international nongovernmental organiza- 16 research reports, including one on Climate Change
tions contributing to these advances, the Asia-Pacific Implications and Adaptations of Water Resources in Paki-
Network for Climate Change organized an early study stan (Ali et al., 2009), which included a section on policy
of water resources impacts of climate change in South needs. The GCISC studies contributed to a Planning
Asia (APN, 2004). More recently, ICIMOD has sup- Commission Task Force Report on Climate Change. The
ported cooperative international programs on snow and federal cabinet adopted a climate change policy that
ice hydrology in the Himalayan region (e.g., ICIMOD's has substantial water resources provisions and a new
INDUS8 and HKH-HYCOS9 programs). Other inter- Ministry on Climate Change in 2012. These national
national nongovernmental organizations (NGOs) have actions occur at a time of constitutional devolution of
undertaken comparative case study analyses of water authority for environment, agriculture, and other sec-
management in the context of climate change across tors to the provinces and political uncertainty.
the region (e.g., ISET, 2008; Moench and Dixit, 2004; Nepal has been an early leader in scientific assess-
see also the International Water Management Institute ments of climate change on water resources man-
[IWMI] website10). agement (Gyawali, 2011). Nepal created a National
Adaptation Programme of Action followed by a Nepal
Formulation of National Water and Climate Change and Development Portal,12 which
Climate Policies has a national branch of the Climate Action Network,
youth alliances, and NGO associations. These efforts
Several countries have articulated national water occurred within what has become a larger context of
policies related to climate change. In 2012, India issued constitutional and governance uncertainties.
a new Draft Water Policy that includes numerous refer- Bhutan has placed growing emphasis on climate
ences to and a major section on adaptation to climate change and hosted the SAARC meeting on cli-
change (Government of India, 2012). The Ministry mate change at Thimpu in 2010. Its water policy is
situated under its Ministry of Agriculture, though it
7 http://www.rimes.int/about_overview.php.
8 http://www.icimod.org/?q=265.
9 See http://www.icimod.org/?q=264.
10 See http://www.iwmi.cgiar.org/Topics/Climate_Change/ 11 See http://www.climatechangecell.org.bd/.
default.aspx. 12 See http://www.climatenepal.org.np/main/.
OCR for page 70
70 HIMALAYAN GLACIERS: CLIMATE CHANGE, WATER RESOURCES, AND WATER SECURITY
also has a substantial hydropower program under its states and districts is associated with increasing refer-
Department of Energy. ences to climate change in water sector planning docu-
Afghanistan is concentrating on reestablishing ments at those levels, the actual implications for bud-
hydrological monitoring and water resources plan- geting, management, and governance are less evident.
ning after a prolonged interruption. Water policy is The largest cities in South Asia are developing climate
addressed in the Ministry of Agriculture, Irrigation, adaptation plans that include water systems, but the
and Land, which raises an interesting point of compari- rapidly growing proportion of secondary and tertiary
son across countries where water and climate policies cities show limited evidence, capacity, or higher-level
are variously situated in ministries of agriculture, water support for addressing hydroclimate effects on water
resources, and environment. supply, drainage, or wastewater management. At local
scales of irrigation management, however, there is
Uneven Subnational, State, and Local Water substantial practical experience with hydroclimate
Management Capacity adjustment. The robustness of these local forms of
adaptation in relation to longer-term and larger-scale
Recent decades have witnessed trends toward trends in climate variability associated with snow and
devolution of water governance from national or con- ice hydrology is less well known.
current jurisdiction to state and local levels (i.e., the
"subsidiarity principle" in the Dublin Statement on CONCLUSIONS
Water and Sustainable Development, 199213). Irriga-
tion departments in India and Pakistan are situated at Key features of the human geography of the HKH
the state and provincial level of government. In the case region were identified at the workshop by the break-
of Pakistan, although some recent annual plans for the out groups on Hydrology; Water Supply, Use, and
provinces refer to climate change, provincial budgets Management; and Demography and Security. Starting
and department plans for 2012 do not yet include from those concepts, the Committee used its expert
major climate change adaptation analyses, programs, judgment, reviews of the literature, and deliberation to
or policies analogous to those being developed at the develop the following conclusions:
national level.
In comparison with government, however, the past · Rural and urban poor may be most at risk, in
generation of social science research on local irrigation part because the poor are least likely to be able to ret-
management by farmers in South Asia underscores rofit, move, or rebuild as needed when faced with risks.
their keen perception of and adjustments to hydro- However, the environment is not the only driving factor
climate variability (see, e.g., numerous IWMI field for migration and other adjustments.
research studies of irrigation in South Asia;14 IUCN, · Social changes in the region have at least as
2008; Kreutzmann, 2000). much of an effect on water demand as environmental
It seems reasonable to summarize that at this time factors do on water supply, leading to stress. Existing
international and national water organizations are stress could be exacerbated by climate change in the
making significant advances toward water resources future.
assessments of climate change that include snow and · Future population growth in specific watersheds
ice hydrology. National water agencies are devoting or elevation zones is uncertain, but there is certainty
increasing emphasis to climate impact and adaptation that the region will become increasingly urbanized.
assessment. It is less clear how these assessments affect · Water resources management and provision of
management, policy, and interagency water coordina- clean water and sanitation is already a challenge in the
tion. Similarly, while devolution of water governance to countries that share the Himalayan watersheds. The
adequacy and effectiveness of existing water manage-
13 http://www.wmo.int/pages/prog/hwrp/documents/english/
ment institutions is a reasonable, if coarse, indicator of
icwedece.html. how the region is likely to cope with changes in water
14 http://www.iwmi.cgiar.org/Publications/index.aspx. supply.
OCR for page 71
HUMAN GEOGRAPHY AND WATER RESOURCES 71
· Changes in seasonal streamflow could have · Water management assessments have advanced
significant impacts on the local populations by altering over the past 5 to 10 years, although their implemen-
water availability patterns and affecting water manage- tation in water policies and programs is less clear; to
ment decisions and policies for irrigation, municipal, date, there is limited penetration to lower levels of
industrial, and environmental use. governance or support for local water managers who
· Average aggregate water-use data provide face the greatest risk.
crude estimates of water supply, demand, and scarcity. · Water use has been increasing over time in both
Increasing the detail, consistency, and accessibility of the Indus and Ganges/Brahmaputra basins, and this
water-use data (along with streamflow and aquifer data trend will continue for the next several decades, with
as discussed in Chapter 2) are key priorities for sound irrigation by far the largest use.
regional water assessment.
OCR for page 72
