Start Date: 2001
End Date: 2004
Full Citation:
U.S. Environmental Protection Agency, $715,141, 2001–2004. An integrated modeling approach to predict the effects of watershed management on the eutrophication of reservoirs in the Central Plains. PI: S. Wang. Co-PI: D. Huggins.
Category:
- Aquatic
Associated with the KU Field Station: No
Research Summary:
The four water quality problems that appear to be the most common in Central Plains lentic waterbodies are:
- Elevated plant nutrient levels and concurrent plant biomass increases;
- Elevated suspended solids levels and siltation that alter aquatic habitats and reduce light penetration, aesthetics, and waterbody depth and volume;
- Occurrence of elevated toxic chemicals, particularly pesticides;
- Objectionable taste and odor conditions
Due to the intensive agricultural activities of this region, excess nutrients and siltation most commonly contribute to eutrophication.
To address this concern, CPCB conducted an investigation into the regional application of watershed and reservoir models in estimating the potential effects of historic, current, and projected nutrient loads on reservoir eutrophication. Internal nutrient recycling in four TMDL reservoirs and their associated inflow streams were studied using several complimentary approaches. First, sediment P-release studies were conducted to determine nutrient release rates. In conjunction, the nutrient content of the sediment was measured and entire sediment nutrient pools were estimated for each reservoir. We also initiated a research program to quantify sediment re-suspension rates within reservoirs, and the ecological impacts of these sediments on lake processes. A self-cleaning turbidity meter that collects measurement at 15-minute intervals was placed near the bottom surface of each reservoir to document seasonal patterns and rates of sediment re-suspension. Based on these results, we conducted bioassay sediment addition experiments to determine the direct effects of sediment re-suspension on water column nutrient concentrations and algal production. Finally, the comprehensive data collected from this proposed research was combined with data from a current study of external nutrient loading in the same TMDL reservoirs.
These data were then used to calibrate and validate the selected watershed model (AnnAGNPS) and reservoir model (BATHTUB). These project efforts addressed many of the regional TMDL (Total Maximum Daily Load) and nutrient criteria development needs related to identification of natural and anthropogenic nutrient levels and nutrient load reductions on lentic and lotic waterbodies in the Central Plains region. The project developed an integrated AnnAGNPS-GIS interface to assist decision makers to assess watershed and reservoir management plans.
Reports:
Wang, S.H., D. Huggins, N. Lim, W.W. Spotts, A.R. Dzialowski. 2005. Predicting the effects of watershed management on the eutrophication of reservoirs in the Central Plains: An integrated modeling approach. Kansas Biological Survey, Lawrence, KS Report No. 123:104 pp.
CPCB, KBS, KU Geography. 2005. Extension for BATHTUB: ArcInterface User's Manual. Kansas Biological Survey, Lawrence, KS Report No. 122:35 pp.
Wang, S.H., D. Huggins, N. Lim, D. Baker, W.W. Spotts, C.A. Goodrich, J. deNoyelles, S. Campbell, L. Frees, C. Volkman. 2003. Cheney Reservoir water quality and its watershed assessment. Kansas Biological Survey, Lawrence, KS Report No. 112:37 pp.