云南省楚雄州区域洪水洪峰流量变化特征研究

Study on variation characteristics of regional flood peak discharge in Chuxiong Prefecture of Yunnan Province

云南省楚雄州水旱灾害频发且常交替出现,为分析该地区水文特性,以区域内9个基本水文站实测年最大洪峰系列资料为依据,采用水文统计、累积距平、线性倾向分析、Manner-Kendall突变检验、小波分析等方法对其洪水特性进行了研究。结果显示,楚雄州水文特性具有一定的地区性,在气候、地理环境、人类活动等因子共同作用下,基本特征发生变化。各水文站1975年之前洪峰流量多呈上升趋势,1975~2000年变化较为平稳,进入21世纪后呈显著性下降趋势。7个水文站点发生洪峰流量均值变异,元江水系突变年份在1970年代,金沙江水系在2000年后,突变后均值减小。楚雄州区域洪水共同呈现5~7 a尺度的周期性变化特征。另外,从区域极端洪水年际变化规律上来看,楚雄州年极端高洪水超标率呈降低趋势,年极端低洪水超标率呈显著上升趋势。结合均值突变分析表明,2000年后,楚雄州水文年景偏旱,尤其是2009年以来,旱灾成为楚雄州面临的主要自然灾害问题。本研究成果将为楚雄州防汛抗旱提供理论参考。

Frequent natural disasters such as flood and drought occur alternately in Chuxiong Prefecture of Yunnan Province.To analyze its hydrological characteristics,based on the measured annual maximum peak discharge series data of 9 basic hydrological stations,the flood characteristics were studied by hydrological statistics,cumulative anomaly,linear trend analysis,Mann Kendall mutation test and wavelet analysis.The results showed that the hydro⁃logical characteristics in Chuxiong Prefecture have certain regional characteristics and the basic characteristics changed under the joint action of climate,geographical environment,human activities,etc.The peak discharge of each hydrological station showed an upward trend before 1975,relatively stable change from 1975 to 2000 and a sig⁃nificant downward trend after 2000.The mean peak discharges of 7 hydrological stations changed.The peak dis⁃charge mutation year of the Yuanjiang River system was in 1970s,and that of the Jinshajiang River system was after 2000.The mean peak discharge decreased after mutation.The regional flood in Chuxiong Prefecture was character⁃ized by periodic variation of 5~7 years.In addition,from the interannual variation law of regional extreme flood,the exceeding rate of annual extreme high flood decreased,and the exceeding rate of annual extreme low flood increased significantly.Considering the mean value mutation analysis,the hydrological characteristics of Chuxiong Prefecture is drought after 2000,especially since 2009.The drought has become the main natural disaster in Chuxiong Prefec⁃ture.The results can provide a theoretical reference for flood control and drought relief in Chuxiong Prefecture.