The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of trea...The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of treatment. How enterprises can make reasonable decisions on their water environment behavior based on the external environment and their own factors is of great significance for scientifically and effectively designing water environment regulation mechanisms. Based on optimal control theory, this study investigates the design of contractual mechanisms for water environmental regulation for small and medium-sized enterprises. The enterprise is regarded as an independent economic entity that can adopt optimal control strategies to maximize its own interests. Based on the participation of multiple subjects including the government, enterprises, and the public, an optimal control strategy model for enterprises under contractual water environmental regulation is constructed using optimal control theory, and a method for calculating the amount of unit pollutant penalties is derived. The water pollutant treatment cost data of a paper company is selected to conduct empirical numerical analysis on the model. The results show that the increase in the probability of government regulation and public participation, as well as the decrease in local government protection for enterprises, can achieve the same regulatory effect while reducing the number of administrative penalties per unit. Finally, the implementation process of contractual water environmental regulation for small and medium-sized enterprises is designed.展开更多
The digital elevation model(DEM)is a type of model that has been widely used in terrain analysis and hydrological modeling.DEM resolution influences the hydrological and geomorphologic features of delineated catchment...The digital elevation model(DEM)is a type of model that has been widely used in terrain analysis and hydrological modeling.DEM resolution influences the hydrological and geomorphologic features of delineated catchments and consequently affects hydrological simulations.This study investigated the impacts of DEM resolution on the performance of the XAJ-GIUH hydrological model,a model coupling the widely used Xinanjiang(XAJ)hydrological model with the geomorphologic instantaneous unit hydrograph(GIUH),in flood simulations in small and medium-sized catchments.To test the model performance,the model parameters were calibrated at a fine DEM resolution(30 m)and then directly transferred to the simulation runs using coarser DEMs.Afterwards,model recalibration was conducted at coarser DEM resolutions.In the simulation runs with the model parameters calibrated at the 30-m resolution,the DEM resolution slightly affected the overall shape of the simulated flood hydrographs but presented a greater impact on the simulated peak discharges in the two study catchments.The XAJ-GIUH model consistently underestimated the peak discharges when the DEM resolution became coarser.The qualified ratio of peak simulations decreased by 35%when the DEM resolution changed from 30 m to 600 m.However,model recalibration produced comparable model per-formances when DEMs with different resolutions were used.This study showed that the impact of DEM resolution on model performance can be mitigated by model recalibration to some extent,if the DEM resolution is not too coarse.展开更多
文摘The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of treatment. How enterprises can make reasonable decisions on their water environment behavior based on the external environment and their own factors is of great significance for scientifically and effectively designing water environment regulation mechanisms. Based on optimal control theory, this study investigates the design of contractual mechanisms for water environmental regulation for small and medium-sized enterprises. The enterprise is regarded as an independent economic entity that can adopt optimal control strategies to maximize its own interests. Based on the participation of multiple subjects including the government, enterprises, and the public, an optimal control strategy model for enterprises under contractual water environmental regulation is constructed using optimal control theory, and a method for calculating the amount of unit pollutant penalties is derived. The water pollutant treatment cost data of a paper company is selected to conduct empirical numerical analysis on the model. The results show that the increase in the probability of government regulation and public participation, as well as the decrease in local government protection for enterprises, can achieve the same regulatory effect while reducing the number of administrative penalties per unit. Finally, the implementation process of contractual water environmental regulation for small and medium-sized enterprises is designed.
基金supported by the National Natural Science Foundation of China(Grants No.51979070 and 52079035)the National Key Research and Development Program of China(Grant No.2018YFC1508103)+1 种基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20180022)the Six Talent Peaks Project in Jiangsu Province(Grant No.NY-004).
文摘The digital elevation model(DEM)is a type of model that has been widely used in terrain analysis and hydrological modeling.DEM resolution influences the hydrological and geomorphologic features of delineated catchments and consequently affects hydrological simulations.This study investigated the impacts of DEM resolution on the performance of the XAJ-GIUH hydrological model,a model coupling the widely used Xinanjiang(XAJ)hydrological model with the geomorphologic instantaneous unit hydrograph(GIUH),in flood simulations in small and medium-sized catchments.To test the model performance,the model parameters were calibrated at a fine DEM resolution(30 m)and then directly transferred to the simulation runs using coarser DEMs.Afterwards,model recalibration was conducted at coarser DEM resolutions.In the simulation runs with the model parameters calibrated at the 30-m resolution,the DEM resolution slightly affected the overall shape of the simulated flood hydrographs but presented a greater impact on the simulated peak discharges in the two study catchments.The XAJ-GIUH model consistently underestimated the peak discharges when the DEM resolution became coarser.The qualified ratio of peak simulations decreased by 35%when the DEM resolution changed from 30 m to 600 m.However,model recalibration produced comparable model per-formances when DEMs with different resolutions were used.This study showed that the impact of DEM resolution on model performance can be mitigated by model recalibration to some extent,if the DEM resolution is not too coarse.
