Aiming at the influence of transition between meteorological drought and flood on runoff,based on the daily precipita-tion and flow data in Jialing River Basin,the spatio-temporal distribution and evolution laws of drought-flood abrupt alternation were analyzed by long-term and short-term drought-flood abrupt alternation indexes,and the response degree of runoff chan-ges to different types of abrupt alternation was quantitatively evaluated.The results showed that there have been 8 drought-flood abrupt alternation events in the Jialing River Basin during the flood season from 1977 to 2022,6 of which occurred in the 2000s and after.Spatially,the frequencies of drought-flood abrupt alternation in southern areas,central areas,and the surrounding areas of the northwest were the largest above17%.On the monthly scale,the highest frequency appeared in the period from June to Ju-ly,which was beyond 20%.When flood-to-drought turns occurred in the flood season,the runoff of Beibei,Luoduxi,Wusheng,and Xiaoheba stations in the first half flood season increased by 57.52%,38.74%,85.50%,and 99.73%on average,and re-duced by20.82%,49.83%,22.64%and 14.53%on average in the second half period.Inversely,under the influence of the drought-to-flood events,the first half runoff of those stations decreased by 31.17%,45.77%,28.83%,and 26.16%on aver-age,and increased by 31.45%,47.17%,24.31%,and 3.27%respectively in the latter half period.The monthly scale also showed similar laws,indicating that drought-flood abrupt alternation had a significant impact on the runoff of the Jialing River.The research results can provide scientific reference for the operation of cascade reservoirs and watershed water security.
关键词
旱涝急转/径流变化/时空分布/嘉陵江流域
Key words
drought-flood abrupt alternation/runoff change/spatio-temporal distribution/Jialing River Basin
维普
万方数据