Advancing Land Change Modeling Opportunities and Research Requirements (2014) / Chapter Skim
Currently Skimming:
1 The State of Land Change Modeling
1 The State of Land Change Modeling
Pages 11-28
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From page 11... ...
Due in part to an explosion in observational and monitoring data on land cover and spatially explicit environmental and socioeconomic data, as well as advances in analytical and technological infrastructure, LCM is now entering a phase with new possibilities for development that could help address a large range of decisions that affect human-environment systems. These advances permit problems to be addressed in greater detail and with better representation of the underlying processes.
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From page 12... ...
Geological Survey and the National Aeronautics and Space Administration to review the present status of spatially explicit LCM approaches and describe future data and research needs so that model outputs can better assist the science, policy, and decision-support communities. They were also asked to provide guidance on the verification strategies and data and research requirements needed to enhance the next generation of models.
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From page 13... ...
In general, scientists build LCMs to test theories and concepts of land change associated with human and environment dynamics and to explore the implications of these dynamics for future land changes under scenarios that elude real-world observation. The policy and practitioner communities are concerned with guiding land use decision making, for which LCMs provide value by enabling exploration of the possible outcomes of those decisions.
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From page 14... ...
Improvement and Challenges The past two decades have witnessed an expansion and improvement of our understanding of land change dynamics and our ability to project changes into the near-term future through many types of LCMs, especially those drawing on remote sensing data of land cover (as opposed to land use) and directed to changes in the biophysical dynamics of land systems (Agarwal et al., 2002; Lambin, 1997; Parker et al., 2003)
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From page 15... ...
, limitations due to development of model inputs from the raw data (e.g., lack of a single ontology for land use, land cover, or other land variables that can be used for classification across all applications) , and limitations due to poor coordination of or restricted access to a variety of public and proprietary primary data about the land systems.
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From page 16... ...
. Land system – a set of biophysical processes and human actors and organizations, together with the interactions among them, expressed spatially in the form of a mosaic of land units with different kinds and degrees of land uses and land covers.
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From page 17... ...
These distinctions are important because modeling approaches have been developed to support science and decision making in land change for a variety of
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From page 18... ...
depending on variations in boundary conditions or stochasticity in the parameters or processes, further challenging attempts at identification. Modeling approaches range from inductive (or pattern based)
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From page 19... ...
, and a clear understanding of the different requirements of each of these communities as well as their close connection provide context for the later sections of this report. In general, science is concerned with generating and organizing knowledge, and the field of land change science and related disciplines build LCMs to formalize and test land change and associated theory and explore scenarios where real-world experimentation is not possible.
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From page 20... ...
and serves as a touchstone for later discussions about the relative value of different modeling approaches at different stages in the decision process. Problems (e.g., flooding)
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From page 21... ...
. Land cover changes affect runoff and nutrient loadings, and can be adjusted in scenarios to evaluate the effects of alternative land-related patterns on achieving water quality goals.
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From page 22... ...
A key component of the CBP is the use of an LCM, based on SLEUTH, to provide scenarios of land use and land cover that can be input to the Chesapeake Bay Watershed Model. Current and future scenarios of land change are entered as input to the CBP Scenario Builder to develop parameter sets to parameterize the water shed model for simulation of stream flow, nitrogen, phosphorus, and sediment loading to the Bay.
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From page 23... ...
MEASUREMENT AND CHARACTERIZATION OF LAND CHANGE Land change modeling confronts a rapidly changing data infrastructure that affords large opportunities for improved models and their application, but it also entails a number of important issues about data quality and assessment that require consideration during model development and testing. These include issues related to remote sensing of land change as well as other data on the various social and biophysical characteristics that define the land system and its drivers within LCMs.
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From page 24... ...
With archival records from Landsat, long time series are being coupled with high-temporal-frequency and high-spatial-resolution analyses. This increased temporal frequency improves our ability to characterize dynamics in the land system, diagnose temporal nonstationarity, and develop empirical parameter sets for LCMs that are better tuned to historical changes.
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From page 25... ...
Whereas for many years, the primary land imaging sensors were Landsat and the Advanced Very High Resolution Radiometer, the LCM community now has at its disposal a large range of additional sensors and types of information for LCM inputs. As discussed in Chapter 3, however, the community is only beginning to harness the synergies possible from algorithm advances in both the LCM and remote sensing communities.
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From page 26... ...
Additionally, the increasing availability of "volunteered geographic information" (Goodchild, 2007) , for which individual citizens provide geographic information, presents a new trove of information for observing and analyzing change (NRC, 2010c)
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From page 27... ...
. STRUCTURE OF THE REPORT Land change models have been and continue to be critical to a large range of uses and users in science and practice.
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