天山南坡开都河流域洪水影响要素分析研究

Analysis of factors affecting peak flow of the Kaidu river on the southern slope of the Tianshan Mountains

根据开都河流域1958-2007年气象与水文资料,利用Mann-Kendall非参数检验技术对春季和夏季洪峰流量变化趋势进行分析,并在此基础上采用滑动t检验和Mann-Kendall方法对其突变点进行检验,最后应用灰色关联对天山南坡开都河春夏季洪峰流量的影响因素进行了分析。结果表明:1958-2007年期间,开都河春季洪峰流量呈减小的态势,夏季洪峰流量呈增加的态势;春季和夏季洪峰流量发生突变的年份分别为1972、1996年;积雪日起6天积温绝对变化、洪峰日起前6天积温变化是春季洪峰流量的主要影响因素,即积雪日前期温度变化与春季升温程度决定了春季洪峰的强度;而洪峰日起前5天降水量、洪峰前期降水量是夏季洪峰流量的主要影响因素,说明洪峰发生前的土壤含水量与降水量多少决定了夏季洪峰流量的大小。

Based on the meteorological and hydrological data in the mainstream area of the Kaidu River from 1958-2007,the change trend and jump point of flood peak discharge in this study area were examined.The change trend of peak discharge was inspected by using Mann-Kendall and the jump point of peak discharge was detected by using Mann-Kendall and moving t-test technique.Eventually,factors influencing Kaidu River’s peak discharge in spring and summer were analyzed by use of grey correlation analysis.Results showed that peak discharge held decreasing tendency in spring and increasing tendency in summer.The analysis on jump point suggested that the mutation year of peak discharge was respectively in 1972 and 1996 in spring and summer.Grey correlation analysis showed that the main driving factors of peak discharge in spring were the absolute change of the accumulated temperatures of first 6 days of complete snow cover,and the change of the accumulated temperature of the last 6 days before peak river discharge,implying that temperature change in both snow cover period in previous winter and initial snowmelt period in spring determines the magnitude of peak discharge in spring.For peak discharge in summer,the main factors were shown to be the amount of precipitation within the 5 days right before peak discharge as well as the precipitation during the first 25 days of the 30 days right before peak discharge,which means that precipitation quantity and soil moisture content before peak discharge time play an important role in shaping peak discharge in summer.