Best management measures research on the BaHe watershed non-point source pollution
NI Yong-ming1 ,XU Yang-ling2*
(1 Beijing museum of natural history,Beijing ,100050 ; 2 The institute of Beijing municipal science and technology information ,Beijing ,100044)
Abstract: At present, China is in the midst of the water pollution constitutes a gradual transition period, the contribution rate of point source pollution gradually decline, the contribution rate of agricultural non-point source pollution is gradually increased This paper uses the SWAT model for soil and water conservation, reducing fertilizer applying pesticide content, reducing the proportion of surface soil fertilizer, returning farmland to forest and comprehensive measures nonpoint source pollution control measures in different BaHe basin cut effect is simulated. Of the basic information database for the SWAT model mainly includes spatial database, meteorological data and management measures, etc. Spatial database mainly includes digital elevation model (DEM), land use map, soil type map, meteorological data, including daily average rainfall, the highest and lowest temperature, solar radiation, wind speed and relative humidity, etc., management measures mainly include crop planting and fertilizing, farming, etc. This study on the model in simulation process of calibration and verification. Model calibration and verification results is good, can be used for simulation BaHe watershed non-point source pollution.Results show that: (1) the soil conservation measures on the reduction effect of nitrogen, phosphorus and DDT as high as 44.4%, relative to the cutting effect of dissolved phosphorus is not very obvious. (2) reduce the rate of measures of dissolved phosphorus, total phosphorus, nitrate nitrogen reduction rate is relatively high, while for other indicators of cutting effect is not obvious; Reduction measures applying pesticide content of DDT cutting effect is good, reduction rate can reach 50.92%. (3) to reduce the proportion of the total surface soil fertilizer fertilizer measures for the reduction of dissolved phosphorus, total phosphorus effect is more obvious, and for other indicators of cutting effect is not obvious. (4) the measures for the indicators of the returning land from farming to forestry has a clear cut. (5) the comprehensive measures for all the indexes have very good cutting effect, overall comprehensive measures can greatly reduce the nonpoint source pollution load in the basin, for improvement of river basin water environment quality can play a huge role. Research for best BaHe watershed non-point source pollution management measures of implementation provides a clear practical decision support.
Key words: Non-point source pollution; SWAT model; BaHe basin; Control measures