POINT AND NON-POINT-SOURCE NUTRIENT CIRCULATION MODELLING FOR THE TAKASAKI RIVER BASIN, CHIBA JAPAN

Study on Vegetable Field Evaluation Index System for Non-Point Source Pollution of Dagu River Basin

This research combined data from soil, terrain and meteorological surveys, with quantitative data from soil and water field studies to determine the leaching processes of nitrogen and phosphorus contaminants from field vegetation into the Dagu River. Using the Gray correlation analysis method, precipitation and irrigation were established as the major driving force behind leaching losses from c...

Modelling of point and non-point source pollution of nitrate with SWAT in the river Dill, Germany

We used the Soil and Water Assessment Tool (SWAT) to simulate point and non-point source pollution of nitrate in a mesoscale mountainous catchment. The results show that the model efficiency for daily discharge is 0.81 for the calibration period (November 1990 to December 1993) and 0.56 for the validation period (April 2000 to January 2003). The model efficiency for monthly nitrate load is 0.66...

Simulation-Optimization Approach for Trading Point and Non-point Source Nutrient Permits

Excess nutrients in surface water systems cause many environmental problems. Some governments restrict nutrient overloading through nutrient permits. Economic theory states that the best allocation of such permits is made via trading. However, nutrient permit trading is complicated by two factors associated especially with non-point sources: (1) time lags between loading and appearance in a wat...

Agricultural Non-point Source Pollution Load Estimation Method in Haihe River Basin

the agricultural non-point source pollution shows some special features such as dispersion, randomness, fuzziness and cumulative compared with industry and other point source pollution. Owing to lacking complete and systematic data on agricultural sources of pollution in the long-term, Agricultural non-point source pollution load of the new method "IS (Investigation-Statistics) estimation metho...

Point-Nonpoint Nutrient Trading in the Susquehanna River Basin: Technical Appendices