基于区域水量-水质的水资源承载力研究

目前国内外对水资源承载力的研究都存在较多关注水资源数量而忽略水质的问题,然而在水资源的实际利用中,最小生态需水量、水环境容量也是水资源承载能力的重要约束条件。基于此,对水资源承载力的概念提出新的理解,从水量和水质角度出发,建立了以最小生态需水量、水环境最大可容纳量为约束条件的水资源承载力模型,提出以人口和经济承载规模来表征水资源承载力。以北京市房山区为例,选取COD和NH3-N为主要污染因子,通过一维稳态水质模型计算研究区域内河道纳污能力,进而推算出在水量-水质约束条件下的水资源可利用量对研究区域经济系统的支撑能力。结果表明:房山区不同水功能区由于其河段长度、现状水质不同,导致纳污能力差别较大;河流对COD和NH3-N的纳污能力分别为4411.92 t/a和121.61 t/a,预测2030年房山区水资源承载力即GDP规模为3348.43亿元、人口数量为243万人。

Water Resources Carrying Capacity Based on Regional Water Quantity and Quality

At present,researches on the water resources carrying capacity both at home and abroad pay more attention to the quantity of water resources but ignore the water quality. However,the minimum ecological water demand and water environmental capacity are also important constraints for the carrying capacity of water resources in the actual utilization of water resources. Based on this,a new understanding of the concept of water resources carrying capacity was put forward. From the perspective of water quantity and water quality,a water resources carrying capacity model with the constraints of minimum ecological water demand and maximum capacity of water environment was established,and the population carrying capacity and economic carrying capacity were proposed to represent the water resources carrying capacity. COD and NH3-N were selected as the main pollution factors,the onedimensional steady-state water quality model was used to calculate the carrying capacity of the rivers in Fangshan District of Beijing,and then the supporting capacity of available water resources under the constraint of water quantity-water quality was calculated. Different water functional areas in Fangshan District had different pollution-carrying capacity because of different river length and current water quality. The pollution-carrying capacities of COD and NH3-N of the rivers were 4 411. 92 t/a and121. 61 t/a,respectively. It was predicted that the water resources carrying capacity of Fangshan District in 2030 was as follows: GDP was 334. 843 billion yuan,and the population was 2. 43 million.