南方农村饮水水源地生态防控体系示范工程——以南京市东龙河小流域为例

Demonstration projects of ecological engineering for rural drinking water source area protection in South China: a case study in Donglong stream catchment of Nanjing

农村饮水水源地保护是保障农村饮水安全的重要组成部分.利用在人工措施适当干预下的半自然或自然生态系统所具有的污染物削减消化能力,因地制宜地建立农村水源地生态防控技术体系是农村饮水水源地保护的重要措施.以南京市江宁区东龙河小流域为例,通过构建包括生态沟渠、滞留塘和稳定塘、植被缓冲带、生态护坡和跌水设施在内的生态防控体系示范工程,有效削减了水体污染物负荷.在小流域出口,水体氨氮质量浓度从劣Ⅴ类提高到Ⅲ类水体质量标准,总氮质量浓度从超过Ⅲ类水质标准的9.38倍下降到1.18倍.小流域出口主要水质指标达到或基本达到Ⅲ类水体质量标准,取得了预期的生态防控效果.

Rural drinking water source area protection plays an essential role for villagers＇ drinking water security. The establishment of ecological engineering system for rural drinking water source area protection is an important step, through utilizing the pollutant mitigation capability owned by natural and semi-natural ecosystems properly interfered by anthropologic activities. This paper takes Donglong stream catchment in Nanjing city as an example. The ecological engineering system including ecological ditches, detention pond, stabilization pond, vegetated buffer strip, eco-revetment, and aeration through dropping water has mitigated pollutant load from Donglong stream catchment. In the catchment outlet, the ammonium-N concentration reduces from higher than category V to lower than category III of national surface water standard （GB 3838-2002）. Total nitrogen （TN） concentration in surface water over the TN value of category III drops from 9.38 times to 1. 18 times. The main water quality criterion approaches category m of national surface water standard （ GB 3838-2002 ） , suggesting that the main goal of the demonstration projects has been reached.