Advancing Land Change Modeling Opportunities and Research Requirements (2014) / Chapter Skim
Currently Skimming:
3 Improving Land Change Modeling
3 Improving Land Change Modeling
Pages 75-106
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 75... ...
However, a number of new applications of models involving developing and evaluating innovative land-based policies, exemplified, for example, by payments for ecosystem services (PES) and REDD+ strategies for curbing deforestation and land degradation while providing income for forestdependent communities, demand a stronger process (i.e.
|
From page 76... ...
Modeling approaches are required that can be used to evaluate how these policies will influence human behavior and in turn affect land cover and human well-being (Nelson et al., 2009)
|
From page 77... ...
We address the issue of data availability in the section on opportunities in observation. Cross-Scale Integration of Land Change Models A major goal of the environmental science community is to develop a predictive and process understanding of the interactions of land change dynamics with climate; ecosystem biodiversity; and the cycling of water, carbon, and nutrients.
|
From page 78... ...
Cross-Scale Integration of LCMs with Other Earth System Models For years, models of a variety of environmental processes have taken land cover and land use as inputs to condition model parameters or set internal fluxes
|
From page 79... ...
. By coupling these models with LCMs, the ability to predict and understand the direct and indirect effects of land management decisions and policies on the trade-offs at short to long time scales on ecosystem services (e.g., food and fiber production, water regulation, maintenance of biodiversity, and carbon storage (Lapola et al., 2010; Nelson et al., 2009; Wiley et al., 2010)
|
From page 80... ...
At the scale of individual land patches, a set of land cover classes will be developed within an ecological successional trajectory following disturbance or other forms of land conversion (e.g., agricultural abandonment, timber harvest or fire)
|
From page 81... ...
Land cover class has a first-order impact on ecosystems by setting model parameters. Because land valuation can be subject to simulated ecosystem components, such as the productivity of agricultural land, a local feedback on decision making is developed at the parcel level, such that less productive agricultural land will have a greater probability of being developed.
|
From page 82... ...
Hierarchical frameworks linking processes over multiple scales can be used to resolve fine- to larger-scale interactions. Bridging LCMs with Optimization and Design-Based Approaches The land change models reviewed in Chapter 2 are described as positive models that seek to explain and predict changes in land use and land cover using either a process-based or a pattern-based modeling approach.
|
From page 83... ...
is a spatially explicit software-based tool developed by the Natural Capital Project (http://www.naturalcapitalproject.org) that provides a means of comparing tradeoffs among ecosystem services by quantifying the value of natural capital in biophysical and economic terms.
|
From page 84... ...
Advances in combining positive and normative approaches will likely require adaptations of both, extending optimization approaches, like Marxan, to include dynamic land systems and adapting LCMs to couple more directly with the environmental and other models that are used to evaluate and quantify outcomes, using tools like InVEST. OPPORTUNITIES IN LAND OBSERVATION STRATEGIES The second set of opportunities is not necessarily associated with the availability of data, but rather in how the enormous quantity of new data can be incorporated into LCMs, how land change modelers can learn about and adapt modeling approaches to use these new data sets, and how land change modelers can help inform the development of image-processing algorithms and data collection schemes that can generate products for the next generation of land change models.
|
From page 85... ...
These high-frequency temporal observations provide new types of information on land cover and land use, such as disturbance (Baumann et al., 2012; Stueve et al., 2011; Zhu et al., 2012) and land-use intensity (Maxwell and Sylvester 2012)
|
From page 86... ...
Remotely sensed data are being used in new ways to generate socioeconomic information, such as the use of the nighttime lights product to estimate variables related to energy consumption (Zhao et al., 2012; Kiran Chand et al., 2009; Townsend and Bruce, 2010; De Zouza Filho et al., 2004) , and economic activity (Chen and Nordhaus, 2011; Henderson et al., 2012)
|
From page 87... ...
Integration of Heterogeneous Data Sources An important challenge to making the most of remotely sensed data for use within LCMs is to integrate them with a variety of heterogeneous data sets. Land change information at a variety of spatial and temporal resolutions can be integrated with socioeconomic and biogeophysical data for coupling of LCMs and other types of models such as models of climate change, ecosystem services and biodiversity, energy use, and urbanization.
|
From page 88... ...
These data should be spatially explicit and available for multiple points in time so that they can be used to specify dynamic spatial models of land change processes. Despite the increasing availability of spatial data on land change, data on the individuals whose choices and interactions generate observed land changes are often missing.
|
From page 89... ...
Making Systematic Land Use Observations In addition to consistency and continuity provided by remotely sensed observations, the reliance of LCMs on heterogeneous data, many of which are not
|
From page 90... ...
OPPORTUNITIES IN CYBERINFRASTRUCTURE A number of the challenges noted above have the potential to find solutions through contemporary advances in cyberinfrastructure. In the following sections, two areas are described in which cyberinfrastructure advances represent potential opportunities for land change modeling.
|
From page 91... ...
Additionally, the LCM community could benefit from distributed data collection facilitated by Global Positioning System– and Internet-enabled mobile devices. A number of recent projects have successfully combined data from traditional sources with geospatial and other data that are crowd sourced from a relevant population and illustrate how data-collection efforts might be structured to facilitate model parameterization.
|
From page 92... ...
These developments will surely require that taking advantage of these opportunities will require new approaches to engineering and implementing LCMs. In another example, the integration of optimization approaches into land change modeling to represent agent decision making and to develop optimal land patterns and functions, particularly at finer resolutions and over heterogeneous areas, requires use of both advanced computational tools and new heuristic approaches to improve their computational feasibility (Batty, 2008; Wright and Wang, 2011)
|
From page 93... ...
Specifically, we identify three kinds of infrastructure investments that would facilitate integration, comparison, and synergy across the community of land change modelers: model infrastructure, data infrastructure, and community governance. The community infrastructure envisioned for land change modeling might be modeled on existing structures developed within other fields.
|
From page 94... ...
To facilitate more expeditious construction of models and greater ease of model modification and integration, a number of open-source modeling environments have been developed that are either intended specifically for land change modeling or more general modeling environments that are suitable for land change modeling applications. In the former category, Dinamica EGO provides an environment for graphical construction of scripts that implement cellular models based on a number of primitive operations, referred to as functors (www.
|
From page 95... ...
Infrastructure to support future developments in land change modeling will surely need to build on these existing resources, but efforts at coordination toward the needs of land change modeling will be beneficial. Such coordinated efforts should aim toward identifying the various constituent processes of land change and developing software components that represent those constituent processes.
|
From page 96... ...
Although a variety of data sets exist to support these needs, further developments in improving spatial and temporal resolutions and better representing changes over time would be facilitated by a formal data infrastructure to support land change modeling. Existing resources include a variety of national and regional agencies supporting data on land cover change, often provided by space agencies as products from satellite image programs.
|
From page 97... ...
. Similar to both of these projects, a data infrastructure to support land change modeling would need to recognize the different thematic data that are necessary; recognize their heterogeneous semantic, spatial, and temporal referencing; and develop a structured system for access and integration in the form of a global integrated land information system.
|
From page 98... ...
A much looser confederation of modelers, this structure provides a rule-based framework within which modelers can contribute a wide range of models and around which specific outcomes or goals do not need to be agreed upon. MODEL EVALUATION There are a variety of practices that can enhance land change modeling to make it more scientifically rigorous and useful in application.
|
From page 99... ...
Sensitivity Analysis Sensitivity analysis is an established procedure whereby the investigator examines the variation in model output due to specific amounts of variation in model input, parameter values, or structure. Sensitivity analysis can be useful to evaluate the importance of uncertainty arising from multiple sources and to understand better the situations in which the modeled system may show important changes in behavior.
|
From page 100... ...
Additionally, sensitivity analysis can be applied to model structure, both for cases where separate models will be evaluated and where there are options for different process representations in the same model. Because differences in structural or dynamic characteristics of a model are important elements of sensitivity, comparison of single-map outputs may be inadequate for evaluating model sensitivity, and evaluations may need to be made over the entire course of a model run (Ligmann-Zielinska and Sun, 2010)
|
From page 101... ...
A standard approach to evaluating the simulation of a land change model is to develop the model through calibration with historical data, for example using two or more maps of land cover during the calibration time interval. The calibrated model then simulates a validation to another time point for which reference data are available.
|
From page 102... ...
This illustrates how the number of patches can be sensitive to an interaction between the configuration of the initial landscape and the quantity of change. Time 1 Time 2 Case A Case B Case C Black means Forest White means Non-Forest
|
From page 103... ...
If there is no baseline for comparison, then the investigator is frequently tempted to use universal standards for model performance, such as defining good as greater than eighty-five percent agreement between the simulated map and the reference map. Universal standards for model performance are problematic, because they are by definition not specific to any particular research question or study site.
|
From page 104... ...
However, in their pattern-oriented modeling approach, the emphasis is on identifying multiple dimensions of pattern that may be very different from one another in character. For example, depending on the goals of the model, the different patterns produced by an agent-based model that could be compared with data, could include maps of land cover, distributions of income, rates of deforestation over time, and numbers of actors engaged in off-farm income.
|
From page 105... ...
Kuminoff (2009) provides an example of how the maintained assumptions of functional form, preference distributions, and neighborhood delineation (all used in structural econometric models of household locational choice)
|
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.