湖南四水流域洪涝灾害特性与减灾战略

Integrate Characteristics and Flood Disasters Reduction Strategy in Xiang, Zi, Yuan and Li River Valley

湖南湘资沅澧四水均属山区暴雨型河流 ,汛期洪涝灾害频发。通过对四水流域近数 10 a洪涝灾害资料分析表明 :洪涝灾害发生频率高 ,且具有多发性、共生性与地域差异性的整体特征。在时间分布上呈现明显的季节性、连年性和循环周期性 ;在空间分布上 ,中上游山丘区山洪灾害频发 ,中下游河谷平原洪涝灾害交织 ,下游尾闾洪溃涝渍灾害并发。随着时间的演进 ,洪涝灾损和发生频率均呈明显的增大趋势 ,据此提出了减灾战略以减轻洪涝灾害损失。

Xiangjiang, Zishui, Yuanjiang and Lishui, flowing in mountainous region, are heavy rain rivers with frequently occurring flood water logging disasters. Based on analyzing the data of flood disasters in about ten years, some conclusions about integrate features of the flood water logging disasters are got as follows: high frequency, simultaneously occurrence and regional difference. In temporal distribution, the flood represents seasonal, annual and periodical aspects. In spatial distribution, mountain torrents repeat in upper and middle reaches in mountainous and hilly area. Flooding and water logging interweave repeat in middle and lower reaches over valley plain, coexist in the lower reaches. Furthermore, the severity and frequency of the disasters being enlarged day by day. So redution strategies are put forward in order to reduce the loss.