宜兴市莲花荡水系整治工程前后生态健康评价

以入太湖莲花荡水系为研究对象,结合2015年4个季度9个采样点的水质学、生物学共7个指标生态调查数据,采用多指标综合评价法,从生物完整性、化学完整性2个方面评价了莲花荡水系整治工程前后的生态健康状况。结果表明,2015年第1、2季度健康状况较差,健康的样点个数分别为3和1,在2015年6月开展清淤工程及集约化畜禽产业整改后,3、4季度健康状况明显改善,健康样点个数分别达到9和7。影响莲花荡水系化学完整性的主要水质指标是TN、TP,3、4季度TN仍超出地表水Ⅴ类标准,处于严重病态,TP为地表IV类标准,处于病态。影响莲花荡水系生物完整性的主要因子是底栖动物,仅监测到20种耐污能力较高的底栖动物物种,而未发现清洁物种。为了进一步改善莲花荡水系生态健康状况,建议开展沿岸农村生活污水的截污治理、农业面源的生态拦阻等污染源控工程,辅以生态岸带建设及湖滨带生态修复等工程。

Ecosystem Health Assessment: A Case Study of Lianhuadang River System before and after the Water Quality Improvement Projects

Ecosystem health before and after water quality environment improvement projects was assessed in terms of chemical and biological integrity, based on the survey of water quality, plankton and benthic animals of 9 samples in Lianhuadang River System in 2015. Results showed that in the first and second quarter, the amount of healthy points were only 3 and 1, respectively, which showed a relatively bad health condition. However, it significantly increased to 9 and 7 in the third and fourth quarter after river dredging and large livestock farm demolished. TN and TP were the key factors influencing the chemical integrity. Even in the third and fourth quarter, TN failed to meet the Class V, while TP barely met Class IV of the Surface Water Quality Standard. Benthic animals have a significant effect on the biological integrity. Only 20 tolerant benthic species were identified, and intolerant species were not found. For a further improvement of ecosystem health of Lianhuadang River Aystem, it is suggested that pollution by the rural domestic sewage and agriculture drainage should be controlled. And eco-remediation of riparian and lakeside zone is also necessary which can be regarded as a supplementary means.