基于综合效益发挥的南方平原区城市湖泊景观水位

Suitable water level for landscape function of lakes in southern plains of China based on optimization of comprehensive benefits

在总结景观水位与景观环境需水量研究现状的基础上,探讨了湖泊景观水位的概念、特征,认为湖泊景观水位受防洪排涝、市政排水、灌溉、河湖水资源量、航运、生态需水量及调水量等多方面因素的影响。针对景观湖泊的特征,在分析汛期、枯水期城市湖泊景观水位主要影响因素的基础上,采用综合协调景观湖泊各种功能的方法,分别建立汛期、枯水期城市湖泊景观水位的定量计算模式。以王母湖为例,采用该模式计算湖泊景观水位。结果表明:汛期将王母湖景观水位维持在22.5 m,高于水资源综合利用要求水位21.2 m,既有利于防洪排涝安全,又可发挥湖泊灌溉、航运效益,保证鱼类生存;将枯水期景观水位维持在21.9 m,休闲活动平台距水面的距离小于0.5 m,需补水936.2万m3,这时水景观效果与外流域引调水量及投资最优,可以满足游船航行、最低生态需水的要求。

Based on review of research on suitable water levels for landscape functions and water demand for landscape environment, the concept and characteristics of the suitable water level for landscape functions of lakes are discussed. The suitable water level for landscape functions of lakes is affected by various factors, including flood control and drainage, municipal drainage, irrigation water supply, water resources of rivers and lakes, shipping, ecological water demand, and quantity of water diverted. In view of the landscape function of lakes and based on analysis of the main factors influencing the suitable water level for the landscape function of lakes during the flood season and dry season, quantitative calculation models of the suitable water level for the landscape function of lakes in the flood and dry seasons were established, through overall coordination of different functions of lakes. Then the suitable water levels for the landscape function of Wangmu Lake were calculated using the models. The results show that the modeled water level for the landscape function of Wangmu Lake in the flood season is 22. 5 m, which is higher than the water level needed for comprehensive utilization of water resources （21. 2 m）. This modeled water level in the flood season not only improves the security of flood control and drainage, but also ensures the irrigation and shipping functions of the lake and existence of fish. The modeled water level for the landscape function in the dry season is 21. 9 m, with the distance between the leisure activity platform and the water surface being less than 0. 5 m, and the water quantity necessary for diversion into the lake being 9. 362 ×106 m3 . This water level not only helps optimize the water landscape, investment, and the water quantity diverted from other basins, but also ensures the feasibility of shipping and meets the requirement of minimum ecological water demand.