Spatio-Temporal Changes of Key Climatic Elements in the Upper Yellow River Water Conservation Area in Recent 60 Years

Abstract

The upper Yellow River water conservation area is an important section for ecological protection and high-quality social-economic development in the Yellow River Basin.The impact of climate change on the spatio-temporal distribution of its water resources will exacerbate the occurrence of natural disasters， which in turn will affect China's regional ecology and even the living environment of human beings.Based on the CN05.1 gridded air temperature， precipitation， and wind speed data from 1961 to 2016 and the actual evaporation data of GLEAM V3.5a from 1981 to 2020， this paper analyzed the changes of key climatic elements in the water conservation area of the upper Yellow River Basin in the past 60 years.The results are as follows： （1） The air temperature in the research area increased significantly， the variation trend of the air temperature can reach 0.34 °C·（10a）-1， and the largest temperature rise occurred in winter.Maqu county and surrounding areas in Heihe region have seen the most dramatic warming.（2） The regional precipitation increased as a whole， the variation trend of the precipitation is about 9.3 mm·（10a）-1.The growth rate was relatively rapid in spring and summer， and the slowest occurred in winter.The growth trend gradually decreased from the northwest to the southeast， with a significant increase in the arid regions of the west， and a relative decreasing trend in the humid regions of the southeast.（3） After experienced an anomalous rise in the early 1970s， the near-surface wind speed continued to decline， the variation trend of it is about -0.11 m·s-1·（10a）-1， and the wind speed decreased in most regions of the study area， especially in the northern Datong River area.（4） The actual evaporation showed an increasing trend， the variation trend of it is 11.89 mm·（10a）-1， of which the relatively large increases occurred in spring and winter， and the growth rate showed a trend of gradual increasing from east to west.Among them， the increase of the actual evaporation in Zhaling Lake， Eling Lake area and the western part of Datong River area was the most significant， and only a few places in the middle and southeast decreased.（5） From the perspective of precipitation and evaporation， the growth rate of precipitation is slightly higher than that of the actual evaporation during the same period （from 1981 to 2016）， therefore the water conservation area in the upper reaches of the Yellow River Basin also has the trends of warming and wetting as the climate warms.

Keywords

• the upper yellow river water conservation area
• climate change
• spatial variation
• change trend