大型湿地和大气之间不断地进行着能量和物质交换，即湿地自由水面和茂密植被通过蒸发蒸腾使水汽进入大气，部分水分以降雨的形式返回地表，从而改善当地的湿度和降水量[1-2]。以衡水湖及周边24个雨量站1974～2010年年—2010年的降水资料为基础，分别计算了湖区、10 km半径影响区、10～20 km环形影响区、20～30 km环形影响区的平均降水量，据此对衡水湖湿地的降水影响规律进行了分析，并基于降水形成机理探寻其变化的主要原因。研究结果表明，衡水湖湿地由近及远降水量呈明显递减趋势，反映了衡水湖湿地对周边区域气候具有调节作用。

Wetlands and aAtmosphere constantly engaged in the exchange of energy and material constantly, that is , free water surface of wetland and dense vegetation was are in the process of evapotranspirationthrough evapo-transpiration to enter into the atmosphere and a part of water returns to the groundwater as precipitation, thereby increasing the so that water vapour injected into the atmosphere， then formed the rain and returned to the ground, thereby it improved local humidity and precipitation. In this paper, Based on the precipitation data from 1974～2010 of Hengshui Lake and twenty- four24 nearby rRainfall sStations from 1974 to 2010 were used to calculate of periphery ， this article figured out the average precipitation of the Hengshui Lake District ，10- km radius affected zone, 10～2010- to 20- km circular affected zone， and 20- to～30- km circular affected zone. It analyzed theThe effects of the wetland of Hengshui Lake on precipitation were analyzed, and the main reasons were investigated based on the change regularity of different affected zone of Hengshui Lake wetland, and explore the main reason through precipitation formation mechanism of precipitation. The result showsed: that the precipitation decreases Hengshui Lake wetland from the near to the distant distance of the Hengshui Lake Wetland, indicating was obviously decreasing, it revealed that Hengshui Lake wetland has an adjustment function the adjustment effects of the wetland onto the climate of surrounding regional climatearea.