水土保持研究

了解南方农牧交错带降水及干旱特征,可为该区旱涝灾害评估、预测及灾害的积极应对等提供较好的科学依据。基于南方农牧交错带1960—2017年20个气象站点逐月降水量资料,采用标准化降水指数(SPI)、克里金空间插值、小波分析等方法对南方农牧交错带近58年来的降水特征及旱涝灾害时空分布特征进行了研究。结果表明:(1)近58年以来南方农牧交错带年平均降水量以3.98 mm/10 a的速率在增加,年降水量存在31 a左右的丰—枯—丰变化周期;(2)受季风、地形、海拔高差等因素的影响,降水量在空间分布上以维西—理塘—若尔盖为界,高值中心出现在东南部,低值中心出现在西北部,呈现出由东南向西北递减的趋势;(3)研究区20世纪80,90年代涝灾发生的频率较高,在20世纪60,70年代旱灾发生的频率较高,2000年以来旱涝灾害发生的频率有所减少。该区域的年降水量在逐年增加并且存在着明显周期变化、降水空间分布由东南向西北呈递减的倾向; 2000年以来旱涝灾害减少。

In order to understand the precipitation and drought characteristics in the farming-grazing transitional zone of south China, and provide a good scientific evidence for the assessment, prediction and active response of drought and flood disasters in this area, based on monthly precipitation data of 20 meteorological stations in the farming-grazing transitional zone of south China from 1960 to 2017, the precipitation characteristics, spatial and temporal patterns of drought and flood disasters in the farming-grazing transitional zone of south China in recent 58 years were studied by using standardized precipitation index(SPI), Kriging spatial interpolation and wavelet analysis. The results showed that:(1)in the past 58 years, the average annual precipitation of the farming-grazing transitional zone of south China had been increasing at the rate of 3.98 mm/decade, and the annual precipitation had a period of abundance-blight and abundance change of about 31 years;(2)due to the influence of monsoon, topography, altitude and other factors, precipitation in spatial distribution with Vici-Litang-Ruoergai as the boundary presented the high value center in the southeast, low value center in the northwest, showing the trend of decreasing from southeast to northwest;(3)the frequency of waterlogging occurred in the study area in 80s and 90s of the 20th century; then the frequency of drought occurred in the 60s and 70s of 20th century; in the end the frequency of drought and flood disasters had decreased since 2000. The annual precipitation in this area is increasing year by year, and there are obvious periodic changes, and the spatial distribution of precipitation is decreasing from southeast to northwest. Drought and flood disaster have reduced since 2000 in this area.