Water Quantity And Quality Allocation Study Based On Hydrological Cycle And Its Associated Processes

Water shortage is juxtaposed with water pollution. Non-point source pollution has become a major factor of water pollution as the control of point source pollution. While, traditional allocation of water resources is not applicable which do not contain point source and non-point source pollution comprehensive control. Based on the former studies of traditional water resources allocation, this paper proposed a concept of combination allocation of water quantity and quality. We constructed a model which combined with water quantity and quality. We also established a decision-making system for combination allocation of water quantity and quality. Plans of validity of combination allocation of water quantity and quality were discussed which covered the point and non-point source pollution comprehensive control.(1) This paper chose Weihe River basin as the study area. Based on the theory of water binary circulation, we discussed the Dualistic Water Cycle which associated with a concomitant phenomenon of water quality change at Weihe River Basin. Under the certain conditions, water pollution level is positively associated with water using. The water pollution level is affected by changing the pollutants into rivers and runoff which controlled by water consumption.This paper proposed a concept of combination allocation of water quantity and quality. We discussed the social and economic decision-making mechanism for water use and sewerage. This paper also proposed a decision-making model of water use and sewage for socio-economic system. We analyzed the uniqueness and stability of equilibrium solutions which proved the existence of solutions for the model. The essential conditions of combination allocation of water quantity and quality are water shortage and water environmental capacity. Contradiction between fairness and efficiency of combination allocation of water quantity and quality originate from transaction and administration costs. The uncertainty of water resources and water environmental capacity increase the cost of water use and the discharge of wastewater. We also studied the relationship between water use and water pollution. This paper proposed water pollution level curve and available water supply curve for water quality compliance. We found that two curves varied with the socio-economic development. The water pollution level gets better which provide much available standard water to use.(2) We constructed a combination model which coupled the traditional water resources allocation model and hydrological model and studied its subsystems structure and characteristics. We analyzed the various sub-modules data in temporal and spatial scales, provided a method of parameters determination system for combination allocation of water quantity and quality model. The results show that the model was feasible.The nitrogen and phosphorus simulation module has been added to WEP_L model. The nitrogen and phosphorus simulation module contains nutrient transform process in soil, nutrient erosion and transform process in water. According to the traditional allocation of water resources model, we analyzed the constraints of the water quality in optimization allocation model and provided a method to identify pollution-induced water shortage in each section. A composite water quantity and quality allocation decision-making system is established for attuning to the conditions of composite water quantity and quality allocation.(3) In terms of the water resources and water environment assessment in Weihe River basin, we got the information of water supply, water consumption and wastewater and water quality and point sources pollution at the certain rivers. The analysis of ecological water requirement of the Weihe River and its scheduling mechanism have been used as the water quantity and quality demand in this paper. This paper constructed the nitrogen and phosphorus distributed water quality model. According to the hydro logical simulation and water resources assessment results, we established a water resources allocation model which is based on the theory of.water supply for different water quality.Based on water resources development and utilization evaluation, we analyzed the balances of water supply and demand in Weihe River basin, and identified the pollution-induced water shortage. We also used sewage flow data from sewage draining exit as a standard to simulated water use, water consumption and wastewater for urban living and industry. Following the hydrological simulation and sediment simulation results, we testified the suitability of the distributed hydrology and water quality model. Then we discussed point sources and non-point sources pollution load in temporal and spatial spaces in the Weihe River basin. According to the analysis of water supply and demand balances and the simulation results, this paper identified the water utilization issues of the Weihe River basin and built a composite water quantity and quality allocation model to improve the existing configuration schemes. The results were as follow:(ⅰ) we predicted the total pollutant discharge in the simulation of non-quality water supply and identified different quality-induced water shortage issues. (ⅱ) the scenario was simulated with unaltered non-point source pollution and controlled total point pollution Water quality during the dry season has greatly improved with the constantly controlling of point sources pollution. The quality-induced water shortage has greatly reduced. However, the water quality has deteriorated during the flood season which due to unimplemented non-point source pollution control. The crisis of quality-induced water shortage has greatly increased during the flood season. In addition to the point source pollution control, the non-point source pollution control is the essential condition to solve quality-induced water shortage. (ⅲ) based on the point source pollution and non-point source pollution control, the water quality has improved significantly during the flood season. Quality-induced water shortage has disappeared. (ⅳ) water quality in Weihe River basin reaches its standard of water quality which is due to the total point sources pollution control and effective non-point source pollution management implementation. Water supply is not affected by quality-induced water shortage in Weihe River basin.