1957-2019年三江平原降雨洪涝特征分析——以绥滨县为例

Characteristics analysis of rainfall-induced flood and waterlogging in the Sanjiang Plain from 1957 to 2019:A case study of Suibin County

三江平原是我国重要的商品粮基地,近年因洪涝频发直接影响了区域农业生产,带来了较严重的经济损失。利用绥滨县1957-2019年逐日降雨量资料和近40年涝灾发生情况,采用线性倾向估计、P-Ⅲ型频率曲线和M-K突变检验分析了降雨量特征值和各量级雨日的变化趋势与突变情况,将P-Ⅲ型频率曲线分析结果与涝灾发生情况相结合探究绥滨县涝灾发生频率及其原因。结果表明:1957-2019年绥滨县年降雨量和最大1 d降雨量均呈增加趋势,且无突变;最大3 d降雨量呈减少趋势,在1981和1997年发生了突变。小雨和大雨雨日呈减少趋势,中雨和暴雨雨日呈增多趋势,小雨雨日的突变年份为2011和2016年,其余量级雨日均未发生突变。由于县域内地势低平、夏季雨量大、江水顶托及治涝工程不完善等因素,导致涝灾发生率较高,近40年内涝灾发生率为67.5%,其中大型涝灾发生率为30%。将大型涝灾发生率按年代划分,前10年发生率为50%,中间10年为30%,后20年均为20%,1990-2019年水稻种植面积大幅度增加,是该时段涝灾发生率下降的主要原因。研究成果可为区域农田防洪除涝工作提供一定的参考。

The Sanjiang Plain is an important production base for commodity grains in China.In recent years,frequent floods and waterlogging have directly affected regional agricultural production and brought serious economic losses.Based on the daily rainfall data in Suibin County from 1957 to 2019 and the occurrence of waterlogging disasters in the past 40 years,the eigenvalues of rainfall,the changing trends and abrupt changes of rainy days of various magnitudes were analyzed using linear trend estimation,Pearson-Ⅲfrequency curve and Mann-Kendall test method.The results of Pearson-Ⅲfrequency curve were combined with the occurrence of waterlogging to analyze the occurrence frequency and causes of waterlogging in the county.The results showed that from 1957 to 2019,the annual rainfall and the maximum daily rainfall in Suibin County increased and there were no abrupt changes.The maximum 3-day rainfall showed a decreasing trend,with abrupt changes in 1981 and 1997.The rainy days of light rain and heavy rain showed a decreasing trend,whereas those of moderate rain and heavy rain showed an increasing trend.The abrupt changes of light rainy days occurred in 2011 and 2016,whereas those of other rainfall magnitudes did not occur.Due to the low and flat topography,heavy summer precipitation,high water level in rivers outside the area,incompetent water conservancy projects,etc.,the probability of waterlogging in the county was quite high,which approached 67.5%in the last 40 years,and the incidence of large-scale waterlogging was 30%.Dividing the occurrence rate of large-scale waterlogging by time,the occurrence rate was 50%in the first 10 years,30%in the middle 10 years,and 20%in the rest 20 years.The significant increase in rice planting area from 1990 to 2019 was the main reason for the decrease in the incidence during this period.The research results can provide a certain reference for flood and waterlogging control for the regional farmlands.