河道型水库区降水由于受到库区地形和下垫面改变的影响,研究降水与地形和下垫面改变之间的关系对于库区的生产生活非常重要。依据水汽循环理论,考虑了地形起伏引起的气流运动路径改变,以及下垫面变化引起的水库区渗透量、蒸发量和地面植被截留量的变化,推导出局地降水量与地形起伏和下垫面改变之间的关系,以三峡库区重庆段为例,对结果进行验证。计算结果表明:在下垫面改变和地形升高的作用下,年均降水量有所增加,计算结果与库区气象站检测结果较为接近。
Local precipitation in the channel reservoir area is affected by topography and underlaying surface difference, so it is of importance to know the relationship between local precipitation and topography and underlaying surface difference. Based on hydrological recycling and considering changes of flowing path due to topography and infiltration, evaporation, the interception of water by foliage, the authors get the relationship among local precipitation, topography and underlaying surface difference. Taking the Three Gorges Area in Chongqing as an example, the relationship is testified. Results show annual local mean precipitation increases because of underlaying surface difference and topography and the results are approximate to those got from the weather station.