关键词: 浅层地下水, 滴滴涕（DDTs）, 农业区, 苏南地区

Abstract: DDTs pollution of shallow groundwater in a certain agricultural area in South Jiangsu was investigated and characterized. It was found that the highest DDTs concentration detected was 1.04 μg•L^-1 and the highest detection rate 36.67%. The pollution scattered in patches and high concentrations were found mainly in the northeastern part of the study area. The pollution spread in a wide scope and varied seasonally showing a decreasing trend of high water period, normal water period and low water period. In the area, the unsaturated layer was good in anti-pollution performance and clay minerals and organic carbon in the soil were highly capable of adsorbing DDTs, thus retarding transfer of the pollutant into shallow groundwater, which is the reason why in some parts of the area DDTs was not detected in shallow groundwater. Vertical percolation of DDTs polluted surface water was the direct cause of the pollution of the shallow groundwater. Lateral water movement or supply was probably another important DDTs source to shallow groundwater. Therefore, the scope of DDTs pollution in shallow groundwater is limited in the vicinity of surface waterbodies.

Key words: shallow groundwater, DDTs, agricultural district, South Jiangsu