宁波市洪涝灾害的历史与区域分析

本文提出了地区洪涝灾害的历史规律和区域差异分析的一般方法和模式，通过对典型地区（宁波市）洪涝资料的统计分析，探讨了区域洪涝的时段性，周期性，以及与旱灾和人口的关系，文章首次提出了洪涝指数的概念，并以计算洪涝指数的方法表达洪涝灾情区域差异分析的结果。

AN ANALYSS OF THE FLOOD-WATERLOGGING DISASTERS IN NINGBO CITY

ased on the statistical data, the seasonality and periodicity of the flood-waterlogging disasters with relations to droughts and increase of population in Ningbo are discussed. The temporaland spatial evolution laws of the disasters are analysed. It is concluded that the flood-waterloggingdisasters in Ningbo have occurred in tWo low frequency Periods and three high frequency periodsin histor. The fact that regional flood-waterlogging disasters beCOme more and more seriouslymainly resultS from man-made destruction of vegetation and environment due tO the increasingpopulation. The flood-waterlogging index is used to grade the disasters and a map of gradingflood-waterlogging disasers in Ningbo is made.