Chaohe River Non-point Source Pollution Based On Warmf Models And Management Measures, Scenario Analysis And Research

Watershed Analysis Management Framework is a decision support system, which supports watershed management and planning and Total Maximum Daily Loads calculation. Water environment as the center, TMDL as the application module are involved in water quality management, total load calculation and allocation. Consensus Module analyzes the cost/benefit, simulates still calculates different methods to reduce pollution and distribute pollution load to give a reasonable decision for water quality management.Chaohe River as a case study in this paper, databases including meteorological data of precipitation, cloud cover, wind speed and other hydrological data was set. WARMF Module is used to simulate and analyze flow, sediment and water quality of the whole watershed; Water quality of Chaohe River has been simulated by the used of ARCGIS operating software and WARMF Module. Parameters on flow, sediment and water quality has been simulated and calibrated with the data between the year 1991 and 2002 after parameter sensitivity analysis; Non-point source pollution load between 1999 and 2002 was estimated to analyze the spatial and temporal distribution of pollution loads of Chaohe River. TMDL and Consensus Module were used to analyze Best management Practices by changing the width and slope of the buffer zones, the amount of fertilizer application and acreage of the crops to calculate the effectiveness of the load reduction by different BMPs scenario. Besides, cost/benefit of different buffer zones was calculated to build BMPs, so as to balance environment benefits and economic consideration.The conclusions are as follows:1, Simulating results are available by calibrating and validating model parameters with parameter sensitivity analysis and determine sensitive parameters such as soil data, land use data, Manning coefficient, erosion factor, fertilization parameters.2, Sediment, TN and TP pollution load between 1999 and 2002 were estimated. Result of temporal distribution shows pollutions are almost in the flood season, between June and September, and concentrates in the main channel by carrying and sedimentation; TN and TP load are mainly Close to the sewage outfall.3, Different kinds of buffer zones, reducing fertilizer application and acreage of the crops were analyzed. Result shows buffer zones have best effectiveness of pollutants reduction, and the cost/benefit analysis shows 20m width buffer has the best result in environment benefits and economic consideration.