花溪区思雅河水质分析与评价

Analysis and Evaluation of Siya River Water Quality in Huaxi District

在花溪区思雅河大学城段布设10个采样点,监测pH值、温度(T)、悬浮物(SS)、化学需氧量(COD)、氨氮(NH3-N)、总磷(TP)和细菌总数(TPC)等指标,并采用单因子指数法、综合指数法和模糊综合法3种方法对水质进行评价。结果表明:河流主要污染指标为COD,且增势最明显,TPC和NH3-N测定值的RSD均超过1,比其他指标变异程度更大;COD和TPC春冬季测定值高于夏秋季,NH3-N测定值秋季最低,TP季节变化不明显,而冬季测定值较其他季节更稳定;思雅河大学城段水质较差,上游水质等级为Ⅳ类,中下游为劣Ⅴ类,主要污染源自农业和高校生活用水;3种方法中,模糊综合法更适用于小流域河流水质的定性定量评价,评价结果更加科学合理。

The water quality at the university town section of Siya River in Hua Xi district was evaluated by single factor index, comprehensive index and fuzzy comprehensive methods, through monitoring the indicators of pH, temperature(T), suspended matter(SS), chemical oxygen demand(COD), ammonia nitrogen(NH3-N), total phosphorus(TP) and total bacteria count(TPC) in 10 sampling sites. The results showed that COD was the main pollution indicator and had the greatest growth. The RSD of TPC and NH3-N measured values were more than 1, which were greater than that of other indicators. COD and TPC measured values were higher in spring and winter than that in summer or autumn. NH3-N was the lowest in autumn. TP had no seasonal variation, but was more stable in winter than that in other seasons. The water quality at the university town section of Siya River was poor, the upriver water quality was of class Ⅳ, the middle and lower reaches were inferior to class Ⅴ. The main pollution came from agriculture and college domestic water. Among the 3 evaluation methods, fuzzy comprehensive method was suitable for qualitative and quantitative evaluation in small watershed, and the evaluation results were scientific and reasonable.