New Strategies for America's Watersheds (1999) / Chapter Skim
Currently Skimming:
5 Connecting Science and the Decisionmaker
5 Connecting Science and the Decisionmaker
Pages 139-163
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 139... ...
INDICATORS OF WATERSHED CONDITION One area that promises to improve watershed science is the effort to develop simulation models that can help predict watershed conditions. At the international level, the Organization for International Economic Cooperation and Development (OECD)
|
From page 140... ...
Efforts to better quantify watershed health are under way in many areas, and one example is presented in Box 5.1. ECOLOGICAL RISK ANALYSIS AND UNCERTAINTY One ingredient that is built into successful watershed management is the use of "good science" in decisionmaking, but even the best science is inadequate to remove all uncertainty when dealing with environmental, economic, and social systems.
|
From page 141... ...
Ecological risk assessment seeks to produce a scientific evaluation of ecological risk that enables managers to make informed environmental decisions (EPA, 1996~. Ecological risk assessment is important for environmental decisionmakers because of the high cost of eliminating environmental risks associated with human activities and the necessity of making decisions in the face of uncertainty.
|
From page 142... ...
if the resource were altered." The endpoint also needs to be something that will be affected by the known or potential stressor. At a watershed scale there are multiple stressors and multiple endpoints, so the interactions become more complicated.
|
From page 143... ...
CONNECTING SCIENCE AND THE DECISIONMAKER 143 assessor must therefore recognize the possibilities for synergism, antagonism, and interference in the measurement of effects. The definition of endpoints can provide a conceptual model that connects ecological entities, stressors, ecosystem processes, and responses.
|
From page 144... ...
Risk characterization requires making an estimate and a description of the risk and communicating those results to the risk manager. Risk estimation determines the likelihood of adverse effects to the assessment endpoints by integrating
|
From page 145... ...
They are Environmental Impacts Statements (EIS) as required by the National Environmental Policy Act 1969, risk assessments, and hazard assessments.
|
From page 146... ...
Ecological risk assessment is shown as a three-phase process including problem formulation, analysis, and risk characterization. Important activities associated with ecological risk assessment include discussions between risk assessors and risk managers and data acquisition and monitoring.
|
From page 147... ...
Risk assessment grew out of the actuarial work of insurance companies concerned with estimating probability and magnitudes of undesirable events. It evolved partly to evaluate environmental risk assessments that arise or are transmitted through the air, water, soil, or biological food chain to man.
|
From page 148... ...
WATERSHED RESTORATION STRATEGIES In response to policy direction from the Clean Water Act of 1977 and its revisions, government agencies at all levels have an increased interest in environmental restoration as a route to sustainable environmental quality while fostering economic vitality. Restoration is a fertile meeting ground for science and management.
|
From page 149... ...
For example, where agricultural practices occur in riparian areas, eliminating such practices may allow the long-term reestablishment of riparian vegetation and associated ecological functions. Natural disturbances would combine with the establishment, growth, and succession of riparian plants to assist in restoring aquatic habitats.
|
From page 150... ...
Such significant habitat alteration can occur in a variety of circumstances, including where hydrologic and sediment transport regimes are affected by dams, irrigation diversions, changes in fire frequency, or conversion of lands to agricultural practices; where introduced plants have replaced native riparian species; where channel incision has lowered local ground water tables and affected hyporheic interchanges with the stream; where estuaries have been filled; or where road construction, agricultural practices, or urban development have reconfigured channel sinuosity or shifted stream location. For many of these situations, watersheds still have the potential to provide habitat for some native species and provide high quality water and relatively natural conditions for humans to enjoy.
|
From page 151... ...
"Substitution" approaches to watershed management are generally directed toward selectively creating, altering, or modifying habitat features to offset the effects of anthropogenic impacts, sometimes in a different location. While the term "enhancement" carries with it the implied message of improvement and betterment of a system, it is important to realize that if ecosystem needs are misinterpreted, a watershed enhancement project may actually shift an ecosystem from one degraded state to another (NRC, 1992; NRC, 1996~.
|
From page 152... ...
The Act's purpose was to protect fish and wildlife habitat, prevent soil erosion, maintain water quality, and ensure a sustainable supply of forest products by specifying prompt reforestation of logged areas. In part, the Forest Practices Act was a response to the federal Clean Water Act and its requirement that states formulate nonpoint pollution control plans, but it was also the result of increased public recognition that unregulated forestry operations had caused significant environmental degradation.
|
From page 153... ...
This process, termed Watershed Analysis, was meant to produce forestry plans tailored to individual watersheds and based on scientific understanding. The watershed analysis protocols developed by TFW participants were formally adopted into law in 1992.
|
From page 154... ...
(As of early 1998, the water quality module was undergoing development, and a tenth module pertaining to monitoring procedures has also not been completed.) The state's watershed analysis procedures have been available for approximately four years.
|
From page 155... ...
Washington does not have an Agricultural Practices Act similar to its Forest Practices Act. Federal land managers have implemented their own versions of watershed analysis, which usually leads to different, more environmentally restrictive management prescriptions.
|
From page 156... ...
The discussion of water resources models can be divided into the following categories (Wurbs, 1994~: demand forecasting and balancing supply with demand water distribution system models ground water models watershed runoff models stream hydraulics models river and reservoir water quality models reservoir/river system operation models Water resources handbooks edited by Maidment (1993)
|
From page 157... ...
This model is a multipurpose environmental analysis system for use by regional, state, and local agencies in performing watershed and water quality based studies. It was developed by the U.S.
|
From page 158... ...
The HSP-F is a simulation model developed under EPA sponsorship to simulate hydrologic and water quality processes in natural and man-made water systems. It is an analytical tool that has application in planning, design, and operation of water resources systems.
|
From page 159... ...
that have been delineated by the USGS for the 18 major river basins in the U.S. Databases used in the analyses include: national resources inventory, national agricultural statistical survey, state soil survey data base, weather parameters, stream flow and reservoir operation data, agricultural census data, input and output of the simulation models and reports for the 350, 6-digit watersheds.
|
From page 160... ...
km.) , hydrologists lacked detailed and processes-based understanding, and thus also lacked the ability to develop simulation models to adequately describe hydrologic response.
|
From page 161... ...
Risk assessment is one method for improving the usefulness of science because it provides improved understanding of the degree and types of uncertainty in management applications; the issue of uncertainty is of special importance to watershed managers because they must often work with incomplete information and because watershed processes inevitably exhibit some random behavior. One area of special promise is simulation modeling, because these can give decisionmakers interactive tools for both understanding the physical system and judging how management actions might affect that system.
|
From page 162... ...
1997a. Evaluation of forest practices prescriptions from Washington State's watershed analysis program.
|
From page 163... ...
1995. Standard methodology for conducting watershed analysis under Chapter 222-22 WAC, Version 3.0.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.