恩施州近50年洪涝与降水时空特征分析

Analysis of Temporal and Spatial Characteristics of Floods and Precipitation in Enshi Prefecture in Recent 50 Years

摘要: 本文采用1970~2020年恩施州8个气象站的降水资料，计算恩施州近五十年的年均降水量的Z指数，判断旱涝等级，并利用平均值法及平均中心对恩施州的洪涝与降水情况进行了时空分析，得到以下研究结果：时间分布上，恩施州在近五十年内出现19次偏涝，35次大涝，33次重涝，共出现了87次洪涝，洪涝主要集中分布在1979~1983年、1996~1998年、2007~2008年、2016~2020年，洪涝类型以重涝和大涝为主；空间分布上，从降水平均值观察，整体降水量多，地区分布存在细小差别，时空分布不均匀，总体呈现南多北少，尤其东南居多、东北和西北较少的特征；从平均中心观察，1970~2020年演变路径无大致规律可循，平均中心演变位置比较分散，但集中在宣恩县，近50年整体平均中心位置主要在宣恩县。

Abstract: Based on the precipitation data of 8 meteorological stations in Enshi Prefecture from 1970 to 2020, this paper calculates the Z index of the average annual precipitation in Enshi Prefecture in recent 50 years, judges the level of drought and flood, and makes a temporal and spatial analysis of the flood and precipitation in Enshi Prefecture by using the average method and the average center, the following research results are obtained: in terms of time distribution, there have been 19 partial floods, 35 large floods and 33 heavy floods in Enshi Prefecture in recent 50 years, with a total of 87 floods. The floods are mainly concentrated in 1979~1983, 1996~1998, 2007~2008 and 2016~2020, and the types of floods are mainly large floods and heavy floods; In terms of spatial distribution, from the observation of the average value of precipitation, the overall precipitation is large, there are small differences in regional distribution, and the temporal and spatial distribution is uneven. On the whole, it shows the characteristics of more in the South and less in the north, especially more in the southeast and less in the northeast and northwest; from the observation of the average center, there is no general law to follow in the evolution path from 1970 to 2020. The evolution position of the average center is relatively scattered, but concentrated in Xuanen county. The overall average center position in recent 50 years is mainly in Xuanen county.