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EVALUATING LANDSCAPE CHANGE AND HYDROLOGICAL CONSEQUENCES IN A SEMI-ARID ENVIRONMENT
Citation:
Kepner, W G., D J. Semmens, C. J. Watts, D. C. Goodrich, AND D A. Mouat. EVALUATING LANDSCAPE CHANGE AND HYDROLOGICAL CONSEQUENCES IN A SEMI-ARID ENVIRONMENT. Presented at 19th Annual Symposium of the International Association of Landscape Ecology, Las Vegas, NV, March 30-April 4, 2004.
Impact/Purpose:
The primary objectives of this research are to:
Develop methodologies so that landscape indicator values generated from different sensors on different dates (but in the same areas) are comparable; differences in metric values result from landscape changes and not differences in the sensors;
Quantify relationships between landscape metrics generated from wall-to-wall spatial data and (1) specific parameters related to water resource conditions in different environmental settings across the US, including but not limited to nutrients, sediment, and benthic communities, and (2) multi-species habitat suitability;
Develop and validate multivariate models based on quantification studies;
Develop GIS/model assessment protocols and tools to characterize risk of nutrient and sediment TMDL exceedence;
Complete an initial draft (potentially web based) of a national landscape condition assessment.
This research directly supports long-term goals established in ORDs multiyear plans related to GPRA Goal 2 (Water) and GPRA Goal 4 (Healthy Communities and Ecosystems), although funding for this task comes from Goal 4. Relative to the GRPA Goal 2 multiyear plan, this research is intended to "provide tools to assess and diagnose impairment in aquatic systems and the sources of associated stressors." Relative to the Goal 4 Multiyear Plan this research is intended to (1) provide states and tribes with an ability to assess the condition of waterbodies in a scientifically defensible and representative way, while allowing for aggregation and assessment of trends at multiple scales, (2) assist Federal, State and Local managers in diagnosing the probable cause and forecasting future conditions in a scientifically defensible manner to protect and restore ecosystems, and (3) provide Federal, State and Local managers with a scientifically defensible way to assess current and future ecological conditions, and probable causes of impairments, and a way to evaluate alternative future management scenarios.
Description:
During the past two decades, important advances in the integration of remote imagery, computer processing, and spatial analysis technologies have been used to better understand the distribution of natural communities and ecosystems, and the ecological processes that affect these patterns. These technologies provide the basis for developing landscape measurements that can be integrated within hydrologic models to determine long-term change and make predictive inferences about the future. This case study employs a system of land cover maps generated from a multi-date satellite imagery database which incorporates Landsat Multi-Spectral Scanner (MSS) imagery from the early 1970s, mid 1980s, and early 1990s and Landsat Thematic Mapper (TM) imagery from 1997 for the San Pedro River (U.S./Mexico). Past and future landscape changes were examined relative to their impact on surface water conditions, e.g. sediment yield and surface runoff. Hydrological outputs were estimated for the years 1973-1997 and predicted twenty years into the future via the integration of scenario analysis with hydrological process and land use models.