Citation:

LOPEZ, R. D., M. S. NASH, D. T. HEGGEM, AND D. W. EBERT. USING BROAD-SCALE METRICS TO DEVELOP INDICATORS OF WATERSHED VULNERABILITY IN THE OZARK MOUNTAINS (USA). Presented at 30th Congress of the International Association of Theoretical and Applied Limnology, Montreal, QC, CANADA, August 12 - 18, 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:

Multiple broad-scale landscape metrics were tested as potential indicators of total phosphorus (TP) concentration, total ammonia (TA) concentration, and Escherichia coli (E. coli) bacteria count, among 244 sub-watersheds in the Ozark Mountains (USA). Indicator models were developed by correlating field-based water quality measurements and contemporaneous remote-sensing-based ecological metrics, using Partial Least Squares analyses. Twenty of the tested broad-scale landscape metrics were predictive of four different sub-watershed vulnerability states, as follows: (1) "most vulnerable", i.e., sub-watersheds that have both high TP and TA concentrations, and high E. coli cell counts; (2) "highly vulnerable", i.e., sub-watersheds that have low TP concentrations, high TA concentrations, and high E. coli cell counts; (3) "moderately vulnerable", i.e., sub-watersheds that have both moderate TP and TA concentrations, and moderate E. coli cell counts; and (4) "least vulnerable", i.e., sub-watersheds that have low TP and TA concentrations, but have moderate E. coli cell counts. The results provide watershed managers with a broad-scale vulnerability prediction tool, specifically focusing on nutrient and bacteriological inputs at multiple scales. Geospatial results are in use by State and Federal managers to target monitoring and restoration efforts for this 21848 square-kilometer watershed that flows directly into the lower Mississippi River.

Record Details: