1950—2010年东北地区旱涝演变特征分析

东北地区为干旱洪涝频发区,也是我国重要的商品粮生产和储备基地,揭示其旱涝演化特征对合理应对干旱洪涝具有重要的现实意义。为此,选择最易受旱涝灾害影响的农业指标,以受旱面积率、受涝面积率为等级划分指标,通过对干旱、洪涝发生频次和发生程度的变化特点分析,揭示了1950—2010年气候变化和人类活动双重作用下的东北地区干旱、洪涝演变特征。结果表明:在气候和人类活动共同影响下,对于干旱灾害,全区的发生频次和程度在时间上呈增加趋势,在空间上呈从北向南逐渐增加的演变格局;对于洪涝灾害,全区的发生频次和程度,在时间上亦呈增加趋势,在空间上恰好与干旱呈相反的演变特征;纵观近1950—2010年旱涝灾害演变,全区呈现干旱、洪涝频发,且以洪涝灾害发生频次更高,但在时间上呈现以干旱增加较快,空间上从北向南呈现由干旱、洪涝并存向仅以干旱为主的演变特点。

Studies on drought and flood transformation in northeast China from 1950 to 2010

Northeast China has been frequently affected by drought and flood disasters. Being the key production base and reserve for commercial grain, it has practical importance of knowing the feature of flood-drought evolution so as to encounter these disasters. Studies are made on drought and flood transformation over the past 61 years （1950-2010） in northeast China under the infuence of climate change and human activities, with selection of agricultural indexes that easily affected by flood and drought and dividing indexes of rate of drought affected area or flood affected area, as well as analysis of characteristic of changes of frequency and intensity. The results show that the frequency and intensity of flood and drought have been magnified along with the time due to the join! impact of climate change and human activities. It also has a tendency of gradually increase from the north to the south. In terms of flood, its frequency and intensity have been increased along with the time and also show an opposite evolution feature with the drought disaster spatially. In the past 61years, the numbers of flood happening are more than that of drought, but the increase of drought is obvious. From the north to the south, the region is transformed from affected by both flood and drought to mainly drought spatially.