Key Laboratory of Groundwater Resources and Environment Ministry of Education, Jilin University, Changchun, 130021, PR China; College of New Energy and Environment, Jilin University, Changchun, 130021, PR China; Jilin Provincial Key Laboratory of Groundwater Resources and Environment, Jilin University, Changchun, 130021, PR China.
Key Laboratory of Groundwater Resources and Environment Ministry of Education, Jilin University, Changchun, 130021, PR China; College of New Energy and Environment, Jilin University, Changchun, 130021, PR China; Jilin Provincial Key Laboratory of Groundwater Resources and Environment, Jilin University, Changchun, 130021, PR China.
Environ Res. 2021 Sep;200:111449. doi: 10.1016/j.envres.2021.111449. Epub 2021 Jun 8.
Yinchuan Plain is a typically intensive cultivated region in the northwest of China. The irrigation return infiltration from Yellow River is the main source of groundwater recharge. Deep soil layers, sandy vadose zones, and dense irrigation canals make the groundwater susceptible to the return flow which contains pollutants originating mainly from agriculture applications, particularly from the extensive use of nitrogen fertilizer and manure. The pollution levels of phreatic water and confined water in NWS areas (non-water source areas) and WS areas (water source areas) of Yinchuan Plain in 2004 and 2014 were evaluated by the single-factor evaluation method, fuzzy comprehensive evaluation method, and average benchmark coefficient method, respectively. Piper trilinear diagram and scatter plots of major ions were used to classify water types and chemical facies, and further analyze the causes of groundwater pollution and the variation tendency of agricultural pollution. The results show that in 2014, about 50% of the groundwater samples were heavily polluted in Yinchuan Plain, the pollution level of phreatic water and confined water in NWS areas was up to level 5. And the groundwater within the standard in 2004 was heavily polluted in 2014 in WS areas, three-nitrogen pollution was the most serious pollutant, and the organic pollution level was grade IV. From the scatter plots of ions, it can be seen that the increase in concentrations of major ions was affected by evaporation-condensation and cation exchange reaction, but the complex ion contents indicated that groundwater was affected by human activities. The intensive agricultural activities, such as over fertilization, artificial irrigation, have led to concentrations increase of some chemical composition in groundwater.
银川平原是中国西北地区典型的集约化耕作区。黄河灌溉回渗是地下水补给的主要来源。深厚的土壤层、砂质包气带和密集的灌溉渠道使地下水容易受到含有污染物的回流影响，这些污染物主要来自农业应用，特别是大量使用氮肥和粪肥。采用单因子评价法、模糊综合评价法和平均基准系数法，分别对 2004 年和 2014 年银川平原 NWS 区（非水源区）和 WS 区（水源区）潜水和承压水的污染程度进行了评价。Piper 三线图和主要离子散点图用于对水类型和化学相进行分类，并进一步分析地下水污染的原因和农业污染的变化趋势。结果表明，2014 年银川平原约有 50%的地下水样品受到重度污染，NWS 区潜水和承压水的污染程度达到 5 级。而 2004 年在 WS 区符合标准的地下水在 2014 年受到重度污染，三氮污染是最严重的污染物，有机污染程度为 IV 级。从离子散点图可以看出，主要离子浓度的增加受到蒸发-冷凝和阳离子交换反应的影响，但复杂离子含量表明地下水受到人类活动的影响。集约化农业活动，如过度施肥、人工灌溉，导致地下水中某些化学成分浓度增加。
