黄山风景区水生态承载力分析

文章以BOD₅为纳污水体的水质影响因子,计算出黄山风景区4条主要纳污水体逍遥溪、丞相源、莲花沟和丹霞溪的丰、平、枯水期的日平均纳污量和年纳污量,得出其水生态承载力总体上较弱,且存在时间与空间分布不均的特征。据此,从浓度控制与总量控制相结合的角度,建立了"水量—水质—水生态系统"阈值模型,提出通过降低用水标准、提高出水指标、进行中水回用、采用节水设备,以缓解黄山风景区水生态承载压力。

Analysis of water ecology capacity in Huangshan Resort

In the 21st century, controls on contamination emission have transformed from the simple concentration control to the combination with concentration and total amount control. But tourism research on water ecological carrying capacity remains concentrated on the concentration control. Water is one of the most important environmental factors in Huangshan resort. Adding water supply can meet the need of an increasing number of visitors. However, concomitant wastewater put tremendous pressure on water ecological carrying capacity. Taking BOD₅ as an influencing factor of water quality, the paper calculates daily average and annual capacities in Xiaoyaoxi, Chengxiangyuan, Lianhuagou and Danxiaxi water bodies during high-flow period, normal water period and low-flow period. The conclusions are: (1) In general, under the premise of sewage discharge up to standard in the Huangshan resort, four major pollutant-holding water bodies can carry sewage discharge from now to 2010. However, after 2010, these four water bodies cannot satisfy sewage discharge the need of and the carrying capacity is saturated. (2) The spatial distribution is uneven in the water ecological carrying capacity. Xiaoyaoxi and Chengxiangyuan have relatively high waste load allocations than Lianhuagou and Danxiaxi. But the sites around Xiaoyaoxi and Danxiaxi have greater water demand, which lead to supersaturation of water ecological carrying capacity in the middle-long term. (3)The uneven temporal distribution is presented. Except individual stream, most of the water bodies can carry anticipative sewage discharge during high-flow and normal water periods in the long term. But during low-flow period, the water bodies except Lianhuagou are seriously overloading. Hereby, the paper builds the threshold model of "water quantity-water quality-water ecology system", and puts forward concrete measures to relieve the pressure on water ecological carrying capacity such as reducing water demand standard, advancing produced-water index, reusing wastewater, adopting efficient water-saving techniques and so on.