The Research Of The Evaluation Of Water Environmental Capacity Of Guilin's Liangfeng River And Its Application On Yanshan New Zone's Development

Based on a comprehensive research with first hand data and a scientific water environment quality evaluation model, with water quality parameter CODcr as the centre, the paper built an one-dimension steady model to evaluate the water environmental capacity of Liangfeng River. The balance of utilization and reserve of Liangfeng River's water environment, the quality of functional areas of water environment and the characteristics of Yanshan New Zone are included in this evaluation.According to the result of the research, under the driest month average flow of 90% guarantee rate, the Liangfeng river water environmental capacity is 1838.86t/a. Deducting 30% capacity as remaining for the mobile development use, the non-point source pollution, and local use, the CODcr permission withdrawal is 1287.20t/a.According to the Yanshan sewage treatment plant plan, in the near future the CODcr emission will be 438 t/a, and will be 1,752t/a in the long term. The Liangfeng River's water capacity will be able to meet the need of Yanshan new economic area's development in the short term, with 849.2t/a surplus capacity, but was unable to satisfy the long run development needs.In order to achieve the sustainable and harmonious development goal for Yanshan New Zone, the local government should consider the environmental restricts when it try to draw a development bule print for the new zone, with methods such as reducing the long term population by 18,000; Enhancing the overall the waste water pollutant reduction rate by improving the efficiency of sewage treatment plant from 80% enhancement to 94.71%, along with the construction of reclaimed water reuse system; Stringent control for new the pollution source; fully utilizing its two branches to reinforce the Liangfeng River, flushing out the dirt ;Strengthening the protection of the ancient Guiliu canal and the Liantang wetland, increasing the water volume; Establishing the water conservancy facilities to increase water current capacity for the Liangfeng river, reducing secondary pollution caused by the pollutant deposition at the bottom of the river, and further changing its water environmental capacity,etc.The study is with practicability and pertinence, which provides basic data and scientific foundation to control the Liangfeng River. In the meanwhile, its thought and method can be used in the similar work of other areas for reference.