珠江三角洲腹地洪水位异常变化及成因分析

Abnormal change of flood water level in hinterland of Pearl River Delta and its cause analysis

珠江三角洲是我国东南沿海的经济发达地区。三角洲地区的防洪安全保障对区域的社会、经济发展具有举足轻重的作用。由于三角洲地区复杂的网河及口门构成,以及径流和潮汐共同影响的水动力条件,使三角洲的洪水水势表现出随时间和空间复杂变化的动态特征。20世纪80年代以来,三角洲地区受水土资源无序开发的人类活动的影响,90年代的洪水表现出了网河腹地河段洪水位异常壅高的现象,使区域的防洪安全受到严重威胁。结合"94.6","98.6"洪水期间三角洲腹地洪水水位异常壅高现象,综合分析了区域洪水位异常壅高的外部及内在成因,为科学制订三角洲地区防洪对策提供技术依据。

Pearl River Delta is one of the most developed areas in the southeast coast of China. The flood control security of the delta plays an important role in the regional social and economic development. Because of the complex constitution of rivers and river mouths and the correlative hydrodynamic influences of run-off and tide, the flood flow in the delta shows an extremely dynamic characteristics temporally and spatially. The flood water elevation in the hinterland of the delta exceptionally rises since 1990's because of the out-of-order exploitation of water-and-soil resources since 1980's, and therefore the flood control safety of the area has been seriously threatened. Based on the exceptional rise phenomena during '94.6' and '98.6', this paper analyzes the interior and exterior causes for the exceptional flood elevation rise in the hinterland so as to provide a scientific basis for drawing up of flood countermeasures in the area.