渭河中游气候变化及其对水文要素的影响

为了探究渭河中游气候变化及其对水文要素的影响,基于渭河中游1970-2017年气候与水文要素资料,运用线性回归、Mann-Kandall检验、小波分析等方法分析了50年来气候及水文要素的时空变化趋势、周期及突变特征。采用双累积曲线法判定径流量突变点,累积量斜率变化率法探讨了气候变化与人类活动对径流量变化的影响程度。结果表明:渭河中游年均气温、气压、水汽压和潜在蒸发量分别呈0.349℃/10 a,0.96 hPa/10 a,0.11 hPa/10 a,2.66 mm/10 a的上升趋势;风速与大气相对湿度每10 a呈-0.16 m/s,-0.65%的下降趋势,各气候要素冬春季节的变化幅度更大;除水汽压外各气候要素均存在明显的周期变化;气温、水汽压及大气相对湿度分别在1996年、1983年和2003年发生显著突变。水文要素中径流量与降水量呈显著下降趋势。气候要素与水文要素的变化有较强相关性。人类活动对径流量减少的贡献率大于气候变化的贡献率,但气候变化的贡献率近年来有增长趋势。

Climate Change and Its Effect on Hydrological Elements in the Middle Reaches of Weihe River

In order to explore the climate change in the middle reaches of Weihe River and its influence on hydrological elements,based on the climatic and hydrological data of the middle reaches of Weihe River from 1970 to 2017,the temporal and spatial variation trend,period and abrupt change characteristics of climatic and hydrological elements in the past 50 years were analyzed by using linear regression,Mann-Kandall test and wavelet analysis.The double cumulative curve method was used to determine the abrupt transition point of runoff,and the cumulative slope change rate method was used to investigate the influence of climate change and human activities on runoff change.The results show that the average annual air temperature,air pressure,vapor pressure and potential evaporation of the middle reaches of Weihe River were 0.349℃/decade,0.96 hPa/decade,0.11 hPa/decade and 2.66 mm/decade,respectively;wind speed and atmospheric relative humidity showed a decreasing trend of-0.16 m/s and-0.65%per decade,and the variation range of each climate element was larger in winter and spring;except water vapor pressure,all climatic factors had obvious periodic change;the temperature,vapor pressure and atmospheric relative humidity changed significantly in 1996,1983 and 2003,respectively;the runoff and precipitation in hydrological elements showed a significant downward trend;there was a strong correlation between climatic factors and hydrological factors;the contribution of human activities to the reduction of runoff was greater than that of climate change,but the contribution of climate change has shown an increasing trend in recent years.