新疆河流洪水与洪灾的变化趋势

Preliminary Approach on the Floods and Their Calamity Changing Tendency in Xinjiang Region

在西北气候由暖干转向暖湿的过程中 ,新疆河流的洪水和洪灾反映明显 .对新疆 2 9条河流选取年最大洪水 ,统计出超标准洪水、2 0a一遇、5 0a一遇洪水的出现频次进行分析 ,结果显示 1987年后洪水量级、洪水频次呈增加的变化趋势 .通过 2 0世纪 90年代以来灾害性洪水出现的频次、灾害损失的变化比较分析 ,90年代以来灾害性洪水尤其是灾害性暴雨洪水和突发性洪水呈现增加的态势 ,1987— 2 0 0 0年的灾害损失与 195 0— 1986年相比增加了 30倍 .

Floods and their calamity in Xinjiang Region may apparently reflect the climatic shift from warm dry to warm humid in Northwest China. Therefore, frequencies of exceed standard flood and floods with possibility of 5% and 2% are worked out from statistics of annual maximum floods of 29 rivers in Xinjiang Regions. The changing tendency and regional distribution of the floods was analyzed. It is found that the flood amount and frequency have been increasing since 1987. By analyzing the frequency of calamity flood and comparing their calamity losses, it is believed that calamity floods, especially rainstorm floods and catastrophic floods, have been increasing since the 1990s. The loss due to calamity foods in 1987-2000 increased 30 times as compared with that in 1950-1986, causing serious damage to the national economic construction, as well as to the life and properties in Xinjiang Region.