华北干旱和半干旱地区的水环境现状和水资源应用问题

The Present Condition of Water Environment and Some Application Problems of Water Resource in Arid and Semiarid Area of North China

分析了地处华北北部干旱和半干旱地区的内蒙古的水环境现状，指出该地区２０００多年来存在着干旱化的趋向。在降水特点上，该地区有降水少而集中、多雷阵雨、雨强大、历时短，因而渗透少、径流大、利用困难等特殊性；认为在水资源中，可用的、能蓄存在当地的和来源有保障的部分才是有效的，而不能利用的部分是无效的；进而提出增加有效水资源量的概念。

The paper analyzed the water environment condition of Inner Mongolia Autonomous Region, which located in the arid and semiarid area of North China. It was pointed out that there is a drying tendency since more than two thousand years ago. About the precipitation characteristics, the author showed some particularities, such as less amount and concentrative distribution, more thunder shower, strong precipitation intensity and short period. These result in the less infiltration, more runoff and low utilization efficiency. The author also introduced the concept of effective precipitation, that is among all of the water resources, only the parts that can be used and stored and the source could be guaranteed are effective, the other parts that can not be used are ineffective. Therefore, the most important thing is to increase the effective water resource.