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EXAMINING PAST LANDSCAPE CHANGE AND FORECASTING HYDROLOGICAL AND BIOLOGICAL RESPONSE TO LAND USE CHANGE
Citation:
KEPNER, W. G. EXAMINING PAST LANDSCAPE CHANGE AND FORECASTING HYDROLOGICAL AND BIOLOGICAL RESPONSE TO LAND USE CHANGE. Presented at UNESCO Workshop on "Methods of Detection and Analysis of change and Feedback in the Earth Sciences", Tucson, AZ, March 26 - 28, 2007.
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:
It is currently possible to measure landscape change over large areas and
determine trends in environmental condition using advanced space-based technologies
accompanied by geospatial data. There are numerous earth-observing satellite platforms
for mapping and monitoring land cover and land-cover change, however the traditional
workhorses have been the Landsat Multi-Spectral Scanner (MSS) and Thematic Mapper
(TM) sensors. Landsat has had a long history of commercial availability (first launch
July 1972), a well developed global archive, and has been widely used for land-cover
change detection and monitoring. During the past two decades, important advances in the
integration of remote imagery, computer processing, and spatial analysis technologies
have been used to develop landscape information that can be integrated within hydrologic
and habitat models to determine long-term change and make predictive inferences about
the future. These technologies provide the basis for developing landscape composition
and pattern indicators as sensitive measures of large-scale environmental change and thus
provide an effective and economical method for evaluating watershed condition related to
disturbance from human and natural stresses. The San Pedro River provides an excellent
case study for using remote sensing as a method of detection and analysis of change. This
project employed a system of land cover maps generated from a multi-date satellite
imagery database which incorporates Landsat MSS imagery from the early 1970s, mid
1980s, and early 1990s and Landsat TM imagery from 1997 to examine change over
approximately a 25-year period. Future environments were examined relative to their
impact on wildlife habitat and surface water conditions, e.g. sediment yield and surface
runoff, using hydrological and habitat process models. A base reference grid for land
cover (year 2000) was modified to reflect stakeholder preferences twenty years into the
future and the consequences of landscape change were evaluated relative to the selected
future scenarios. The San Pedro provides an example of integrating modeling with
advanced earth observing technology to produce information on trend and make plausible
forecasts for the future in which to understand the impact of landscape change on
environmental services.