公元600-2000年宝鸡地区洪涝灾害发生规律

通过对历史文献资料的搜集和整理，对公元600-2000年宝鸡地区洪涝灾害变化阶段、趋势、等级分布和成因进行了研究。结果表明：宝鸡地区洪涝灾害可划分为轻度涝灾、中度涝灾、大涝灾、特大涝灾4级，以中度和大涝灾为主，占灾害记录总数的71.55%，特大洪涝灾害发生较少，占灾害记录总数的8.94%。公元600-2000年的1 400 a可以分为14个洪涝灾害发生阶段: 10、11、12、13、14、15世纪为无洪涝灾害或极少洪涝灾害发生阶段，7、8、9、16、17、18、19、20世纪为洪涝灾害多发阶段。洪涝灾害发生频次具有空间差异，9个县区由多到少依次为：宝鸡、扶风、千阳、凤翔、凤县、陇县、麟游、岐山、眉县。最多与最少之间相差26次，空间差异较大。洪灾集中于夏、秋两季。宝鸡地区洪涝灾害的发生主要是由地理位置、降水和气候异常波动以及人类活动综合因素影响的结果。

Flood Disasters in the Baoji Region during the Period of A.D.600-2000

Through collecting and analyzing the historical data, the variation stages, trends, grades and causes of flood disasters in the Baoji region during the period of A.D. 600-2000 were researched. The results showed that flood disasters in the Baoji region may be divided into 4 grades, WTBX]i.eWTBZ]. the slight, moderate, serious and extremely serious grades, in which the moderate and serious flood disasters were dominant, and their proportion was 71.55% of the total. Extremely serious flood disasters occurred seldom, and their proportion was 8.94% only. In the past 1 400 years, flood disasters occurred seldom in the 10th, 11th, 12th, 13th, 14th and 15th centuries but frequently in 7th, 8th 9th, 16th, 17th, 18th, 19th 20th centuries. There was a spatial difference in occurring frequency of flood disasters, and the frequency was in an order of Baoji > Fufeng > Qianyang > Fengxiang > Feng County > Long County > Linyou > Qishan > Mei County. The difference of occurring frequency of flood disasters between the highest and lowest values was 26 times. Seasonally, flood disasters occurred mainly in summer and autumn. Flood disasters were jointly affected by the geographical location, precipitation, climatic anomaly undulation and human activities.