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Chapter 4: Projecting Future Land Use and Land Cover Patterns and Characteristics

Introduction

The research needed to make projections of possible future patterns and characteristics of land use and land cover change will be based on an understanding of both the historical and contemporary causes and rates and drivers of land use and land cover change.   Research is needed that develops new systematic methods and study designs for land use change modeling, incorporating the forces of change that operate at different spatial and temporal scales.   Predictions of land use and land cover change provide important scientific and practical outcomes   providing insights into possible consequences of change for human and natural systems and the interaction of these systems, and facilitating improved decision making for management of land and of systems in which land dynamics play an active role, such as ecosystems, and water and carbon cycles.   A number of types of models of land use and land cover are being used for explanatory and/or predictive purposes.  

Prediction from models is based on a set of assumptions about the nature and functional form of the drivers of land use and land cover change into the future.   The simplest approach is to assume that the drivers and their functional relationships are similar to those of the recent past.   Evolutionary models applied in the social sciences to represent human adaptability in the face of a changing environment need to be explored as a means to relax the stationarity assumption in land use and land cover models.   Predictions will need to be made in the context of well-defined and reasonable scenarios.

Challenges for the land cover and land use modeling community include a) determining the spatial and temporal information and scales needed to project land use change at the national and regional levels, b) identifying the major feedbacks and interactions between climate, socioeconomic, and ecological influences on changes in land use and land management, c) determining the key sources of uncertainty and major sensitivities in projecting characteristics of land use and land cover change 5 to 50 years into the future.

Specific Research Goals

4.1. To inventory current land use and land cover modeling methods and approaches, examining strengths and weaknesses of various modeling approaches for meeting LULCC research and assessment goals, to compare the data sets used to run these models   and develop methods for determining current model uncertainty and skill.(2 years, Priority1)

This is seen as a first step towards harnessing existing models and knowledge gained from these models, to produce state-of-the-science assessments that match the needs of the CCSP, to refine model data requirements and to advance model capabilities and evaluation methods.   It will be productive to identify a common framework for evaluating modeling approaches for projecting land cover and land use changes at different spatial and temporal scales. This will require an initial review of existing models followed by a series of model intercomparison workshops examining model performance. This task is proposed as an Initial Integrative Pilot Project (see Section 7)

4.2 To develop and apply single-sector (e.g. for urban, agriculture, forest etc.) and combined multi-sector change predictive models, incorporating advances in our understanding of drivers to meet specific CCSP and CCRI objectives. (Ongoing, Priority 2).  

Existing models of land use and land cover change within various sectors will serve some of the purposes for which land use and land cover change projections are required. There is a need for these models to be dynamic, incorporating the processes of land use and land cover change and to be available at a range of time and space scales. Where these models are intended to inform management or decision making, they should be developed and tested in conjunction with the intended stakeholder communities. In some cases linkages and feedback may be needed with models from other elements of the CCSP.   Research is also needed to develop models that fill gaps in the set of existing of models available.  

4.3 Development of a Community Land Use and Land Cover Change Model (CLUCM) (3 years – Priority 1)

An important element of this science strategy is the development of a Community Land Use and Land Cover Change Model (CLUCM) to couple to the Community Climate Model.   This model would most likely require integration of components from existing models and would be very coarse spatially by the standards of existing land use and land cover models, roughly 10-20 km.   The outputs of the model would be land surface characteristics that affect processes in the climate models (e.g., albedo, surface roughness, etc.), but these need to be modeled as outcomes of land use (e.g., urbanization) and land cover (e.g., disturbance) change processes.   The Community Land use and Land Cover Change Model might be a simple distillation of dynamics identified in more spatially and temporally detailed local, regional and national models.   Because a CLUCM would likely rely on climate inputs and produce outputs that affect climate, joint research efforts with climate-change modelers are need to identify appropriate points of interaction and spatial and temporal scales.

Timeline and Costs

Total cost to realize this research strategy focused on projecting land use and land cover change is $40 million over the first 5 years, or an average of about $7 million per year in the first five years.   Funding requirements in years 6-10 will be reduced to $1 million per year to cover model refinement, as projections are increasingly integrated with other elements of the land use and land cover change science program.