气象条件对淀山湖水质的影响

根据2007-2014年淀山湖湖体每月高锰酸盐指数(CODMn)、氨氮(NH3-N)、总氮(TN)和总磷(TP)等水质资料和青浦区气象局月平均气温、降水量和日照时数等气象资料,运用数理统计方法和特征值比较法分析淀山湖湖体CODMn、NH3-N、TN和TP等水质资料变化规律及温度、降水和日照时数等对水质的影响.结果表明:(1)气象条件影响淀山湖湖体水质.平均气温、日照时数影响NH3-N、TN和TP浓度,表现在平均气温高、日照时数多,NH3-N、TN浓度降低,相反平均气温低、日照时数少,NH3-N、TN浓度升高;平均气温高,也会使TP浓度上升,平均气温低,TP浓度降低.降水对水体中CODMn、NH3-N和TN等浓度有稀释作用,降水量多的月份其浓度偏低,相反降水量少的月份其浓度偏高.(2)受气象条件影响,CODMn、NH3-N、TN和TP有季节变化.CODMn浓度4-9月较高,10月翌年3月较低;NH3-N、TN浓度最高值出现在2-4月前后,最低值出现在7-10月;TP浓度最高值出现在7-8月,最低值出现在10月翌年5月.(3)淀山湖CODMn、NH3-N、TN和TP浓度呈下降趋势.

Effects of meteorological factors on the water quality of Lake Dianshan

According to the monthly monitoring data on water quality (permanganate index(COD_Mn), ammonia nitrogen(NH₃-N), total nitrogen(TN), total phosphorus(TP)) and meteorologicalogy (mean temperature, precipitation, sunshine duration) from 2007 to 2014, the change pattern of water quality in Lake Dianshan and the impacts from meteorological factors were analyzed. Results showed that:1) Mean temperature and sunshine duration had significantly negative impacts on NH₃-N and TN. Mean temperature had significantly positive impacts on TP. Precipitation diluted and had negative impacts on COD_Mn, NH₃-N and TN. 2) Water quality exhibited seasonal variations under the meteorological impact. Higher values of COD_Mn appeared between April and September, while lower values between October and March. NH₃-N, TN peaked between February and April, reaching lowest value between July and October. TP peaked during July and August, while lower values appeared between October and May. 3) COD_Mn, NH₃-N, TN, TP showed downward trends.