盐碱地农田排水对查干湖承泄区的水质影响评价

为了评价盐碱地农田排水对承泄区的水质影响，该文选取吉林省前郭灌区的农田排水和查干湖承泄区为研究对象，通过2009－2010年水稻生长季每月定期的野外取样、实验分析水样的K+、Na+、Ca2+、Mg2+、SO42-、Cl-、CO32-、HCO3-、总氮、总磷和化学需氧量，研究了查干湖灌溉灌排系统至承泄区相关排水水质的时空变化，并对查干湖水质进行了评价。结果表明，查干湖承泄区对灌排系统的各水质指标有一定的累积效应。目前查干湖水体pH值平均在7.87；钠吸附比最大值（3.59 (mmolc/L)1/2）出现在5月份泡田洗盐期；总氮含量为1.22 mg/L，低于近12年平均值1.56 mg/L；6月份总磷含量最高，达0.28 mg/L。除化学需氧量超标外，其他水质参数未达到浓度限值，但在丰水期查干湖水体已属IV类水质。该研究可为查干湖承泄区的生态环境预警提供理论基础。

Impact assessment of saline-sodic agricultural drainage on water quality in vented area of Chagan Lake

To evaluate the impact of saline-sodic agricultural drainage on water quality in vented area, the agricultural drainage of Qianguo irrigation area, Jilin province and Chagan lake was chosen as the studied object. In 2009 and 2010, during rice growing season, samples were collected monthly. K+, Na+, Ca2+, Mg2+, SO42-, Cl-, CO32-, HCO3-, total nitrogen, total phosphorus and chemical oxygen demand were recorded. Temporal and spatial variations of water quality from irrigation area to the vented area were analyzed. Water qualtity of Chagan lake was evaluated. The results showed that pH value in Chagan lake was larger than 7.8 at present. The maximum value of sodium adsorption ratio was 3.59 (mmolc/L)1/2, which appeared in May. The total nitrogen concentration was 1.22 mg/L, which was lower than the average value (1.56 mg/L) in the last 12 years. The content of total phosphorus was highest (0.28 mg/L) in June. In addition to chemical oxygen demand, the other indexes of water quality did not exceed the concentration limitations. However, in the flood season, Chagan lake belonged to the IV water quality type. This paper could provide the theoretical basis of ecological and environmental warning for Chagan lake.