Stochastic Watershed Water Quality Simulation for Tmdl Development – a Case Study in the Newport Bay Watershed
نویسندگان
چکیده
Systematic consideration of uncertainty in data, model structure, and other factors is generally unaddressed in most Total Maximum Daily Load (TMDL) calculations. Our previous studies developed the Management Objectives Constrained Analysis of Uncertainty (MOCAU) approach as an uncertainty analysis technique specifically for watershed water quality models, based on a synthetic case. In this study, we applied MOCAU to analyze diazinon loading in the Newport Bay watershed (Southern California). The study objectives included (1) demonstrating the value of performing stochastic simulation and uncertainty analysis for TMDL development, using MOCAU as the technique and (2) evaluating the existing diazinon TMDL and generating insights for the development of scientifically sound TMDLs, considering uncertainty. The Watershed Analysis Risk Management Framework model was used as an example of a complex watershed model. The study revealed the importance and feasibility of conducting stochastic watershed water quality simulation for TMDL development. The critical role of management objectives in a systematic uncertainty assessment was well demonstrated. The results of this study are intuitive to TMDL calculation, model structure improvement and sampling strategy design. (KEY TERMS: stochastic simulation; uncertainty analysis; Management Objectives Constrained Analysis of Uncertainty; Total Maximum Daily Load; nonpoint source pollution; watershed management; pesticide; diazinon.) Zheng, Yi and Arturo A. Keller, 2008. Stochastic Watershed Water Quality Simulation for TMDL Development – A Case Study in the Newport Bay Watershed. Journal of the American Water Resources Association (JAWRA) 44(6):1397-1410. DOI: 10.1111/j.1752-1688.2008.00232.x
منابع مشابه
A Benefit-cost Analysis of Total Maximum Daily Load Implementation
Total Maximum Daily Load (TMDL) implementation generates benefits and costs from water quality improvements, which are rarely quantified. This analysis examines a TMDL written to address bacteria and aquatic-life-use impairments on Abrams and Opequon Creeks in Virginia. Benefits were estimated using a contingent valuation survey of local residents. Costs were based on the number and type of bes...
متن کاملInfluence of Reservoir Infill on Coastal Deep Water Hypoxia.
Ecological restoration of the Chesapeake through the Chesapeake Bay total maximum daily load (TMDL) requires the reduction of nitrogen, phosphorus, and sediment loads in the Chesapeake watershed because of the tidal water quality impairments and damage to living resources they cause. Within the Chesapeake watershed, the Conowingo Reservoir has been filling in with sediment for almost a century ...
متن کاملA “watershed Approach” to Tmdl Development
The State of Minnesota, in an effort to streamline the identification of impaired waters and subsequent TMDL development, has developed a watershed approach to condition monitoring and assessment similar to other states such as Ohio and Indiana. The watershed approach uses intensive biological monitoring (fish and macroinvertebrates) to determine biologically impaired stream reaches. Follow up ...
متن کاملA Comparative Evaluation of State Policies and Programs for Nonpoint Source Pollution Control in the Chesapeake Bay Watershed
The U.S. Environmental Protection Agency (EPA) has reported that over 45 percent of the nation's waterbodies are impaired and has identified nonpoint sources as the major contributors to water quality problems. Although federal and state government agencies have largely controlled pollution from point sources through infrastructure grants and permit programs, few statutes and regulations target...
متن کاملEnhanced HSPF Model Structure for Chesapeake Bay Watershed Simulation
For more than two decades, an HSPF-based watershed model has been used to simulate nutrient and sediment load delivery to the Chesapeake Bay. Over time, the watershed model has increased in complexity commensurate with the management challenges in Chesapeake Bay restoration. The increased complexity poses challenges to the standard application of HSPF for efficient operation of the model in a l...
متن کامل