论文部分内容阅读
水既属于资源的范畴,也属于生态环境的范畴。水是自然界中最活跃的物质,在各种自然资源中,水资源最重要的特征就是它在水循环中不断地被重复。水循环过程作用于每个地区而且是永久性地进行着。因此,对水资源不仅要合理利用,而且更要对它加以保护。一个国家的河川年径流量的多少,反映着这个国家水资源的丰富程度。而降水量的大小反映着河川径流量的多少。我国平均年降水深为630毫米,小于全球陆面上平均年降水深800毫米,也小于亚洲陆面上年平均降水740毫米的量。我国的年降水总量约为60000亿立方米,约占全球陆地年降水总量119万亿立方米的5％。这些降水除蒸发和下渗外,都汇入地面径流。我国河川
Water is not only a category of resources, but also a category of ecological environment. Water is the most active substance in nature. Among all kinds of natural resources, the most important characteristic of water resources is that it is constantly being repeated in the water cycle. The water cycle works in each region and is done permanently. Therefore, not only should water resources be rationally utilized, but it must also be protected. The annual runoff of a country’s rivers reflects the richness of the country’s water resources. The amount of precipitation reflects the amount of river runoff. The average annual rainfall of China is 630 mm deep, less than the average annual precipitation of 800 mm on the global land surface and less than the annual average precipitation of 740 mm on the Asian land surface. The total annual precipitation in China is about 600 billion cubic meters, accounting for about 5% of the 119 trillion cubic meters of precipitation on land in the world. In addition to these precipitation precipitation and infiltration, inflow into the ground runoff. My country river