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通过对许昌地区 ２０００ 年来的历史灾害统计分析， 发现该地区的自然灾害以水旱灾为主，存在有多灾期和少灾期的特点，引起灾害的原因除自然因素外，不合理地利用土地是引起灾害频率增加及灾情加重的主要原因
Through the statistical analysis of the historical disasters in Xuchang since 2000, it is found that the natural disasters in this area are mainly floods and droughts, and there are the characteristics of the disastrous periods and the disastrous periods. The causes of the disasters are irrational use of land except natural factors It is the main reason that causes the disaster frequency increase and the disaster aggravates