The rapid development of urbanization significantly influences the urban geologic environment and especially the underground water environment. In this investigation, two long-term soil water monitoring stations were built in urban and suburban areas of Nanjing city. By using PR2, the soil profile water contents in one meter depth were monitored every day from June to September in 2009. It is found that the soil water content was significantly controlled by weather condition. Its sensitivity to weather decreased as the depth increased. A comparison of the data obtained from the two stations shows that the effect of weather to water content in the urban soil is not as significant as that in the suburban soil. The water content in the urban soil is generally lower than that in the suburban soil. An obvious urban dry island( UDI) effect is observed. During the period of June to September, the average UDI intensity is -9. 1% ,the highest day UDI intensity is about -20. 7% ,the highest month UDI intensity observed in July is a-bout -17.0% ,, and the minimal month UDI intensity observed in September is about-8. 5%. . In addition, it is shown that the temporal and spatial variations of soil water contents depend on the underlying surface properties. For example, the average soil profile water content under cement cover is less than those under grass and bare soil covers. It indicates that cement cover in urban area can obviously intensify the UDI effect. During the monitoring period (from June to September) ,it is found that,in urban area,the average profile water contents under bare soil cover, cement cover and grass cover are 26. 9% , 25. 6% ,and 17. 5% ,respectively; whereas in suburban area,the three average profile water contents are 37. 6% , 37. 6% , (36. 0% , respectively; the water content differences between the urban and suburban soils for grass, cement and bare soil covers are the highest, the intermediate and the lowest, respectively.%城市化的快速发展对城市地质环境尤其是地下水环境产生了深远的影响.以南京市为研究对象,在城区和郊区分别设立长期监测站,采用PR2对南京地区2009年6～9月期间典型地表环境下1m内土体含水量的日变化进行了监测,并对监测数据进行了系统的对比分析.结果表明:土体含水量的日变化规律主要受气候因素的制约,其对日气候因素的敏感程度随深度的增加而递减,城区土体的含水量受气候的影响程度在总体上弱于郊区；通过对比,城市土体中的含水量普遍低于郊区,存在明显的城市干岛效应,在6～9月期间,平均干岛强度为-9.1％,日最大干岛强度达-20.7％,月最大平均干岛强度出现在7月,达-17.0％,月最小平均干岛强度出现在9月,只有-8.5％；在不同的地表环境下,土体含水量的时空变化规律及分布特征存在差异,其中水泥环境下土体剖面平均含水量最小,其次是草地环境和裸土环境,说明城区水泥地面对城市干岛效应起到明显的促进作用；在6～9月期间,城区土体剖面平均含水量为裸土环境(26.9％)＞水泥环境(25.6％)＞草地环境(17.5％),而郊区为草地环境(37.6％)＞裸土环境(37.0％)＞水泥环境(36.0％),其中城郊平均含水量差值最大的为草地环境,其次为水泥环境和裸土环境.
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