水资源.ppt

Water Resources in China Water Resources Water Resources Precipitation River Lake Groundwater Which four main elements(元素)including in water resources? China‘s water situation ： Annual mean precipitation is 648 mm in China , with an estimated discharge of 2711.5 billion m3, 828.8 billion m3 in shallow groundwater resource , and an aggregate annual volume of 2812.4 billion m3. ?年平均降水量为648毫米，估计中国排放，2711500000000立方米，8288.00亿立方米的浅层地下水资源，以及总额28124.0亿立方米的年销量。 Precipitation in various regions of China differs greatly and unevenly in distribution as a result of China’s monsoon climate, topography(地形), and geomorphy(地貌). In the east rainfall is generally heavy, whereas the west has very little rainfall; meanwhile, the south has heavy rainfall, whereas the north has very little rainfall. At the same time, China have more then 50 000 rivers whose catchment area is over 100 k㎡, and 1 500 rivers whose catchment area is over 1 000 k㎡. Out of which, the most famous rivers are Yangtze River, Yellow River, Zhujiang River, and Huaihe River. Besides, there are roughly 24 000 lakes in China a total storage capacity of 708.8 billion m3 and a surface area of 72 000 k㎡. Well-known freshwater lakes are Poyang Lake, Dongting Lake, Taihu Lake, and Hongze Lake. Groundwater resources in the national annual average of about 828.8 billion m3, of which 676.2 billion m3 distributed in the mountainous regions, 187.4 billion m3 distributed in the plains, mountains and plains repeat the exchange of about 348 billion m3. Because of this vast quantity of water, China is ranked the sixth in the world in terms of aggregate annual water resources. However, the available water resources annually per-capita in China is only 2 200m3，which makes China one of the water shortest countries of the world. The scarcity(稀缺) of water resources especially in the north China.