Assessing climate change induced modification of Penman potential evaporation and runoff sensitivity in a large water-limited basin

作者：Liu, Qiang^*; McVicar, Tim R.

来源：Journal of Hydrology, 2012, 464: 352-362.

DOI：10.1016/j.jhydrol.2012.07.032

• Attribution analysis
• Potential evaporation
• Net radiation
• Ecohydrological processes
• Yellow River Basin

Potential evaporation (E-p) reflects the combined effects of four key meteorological variables: (i) net radiation (R-n); (ii) wind speed (u); (iii) relative humidity (rh); and (iv) air temperature (T-a). Here, attribution analysis was conducted to investigate the contribution of the four key meteorological variables to changes of a physically-based E-p in a large water-limited basin, the Yellow River Basin (YRB), China. Then the influences of these changes, and precipitation (P) changes, on streamflow (Q) were explored analytically. Results show that: (i) E-p presented different temporal trends for the water yielding region (WYR) and water consuming region (WCR) with a overall changes of +0.16 mm a(-2) and 0.66 mm a(-2) during 1961-2010, respectively; (ii) trend analysis of E-p and the four key meteorological variables at the basin scale showed that increasing trend in T-a increased E-p during 1961-2010, while changes in R-n and u increased the 1961-1979 E-p rate and reduced it during 1980-1994 and 1995-2010; (iii) revealed by attribution analysis, E-p increased by changes in T-a and rh and reduced by changes of R-n and u in both WYR and WCR, in all, Er rate presented positive and negative trends in the WYR and WCR, respectively; (iv) the changes of Q and actual evaporation (E) are much more sensitive to changes in P than the changes in E-p; and (v) of critical importance for water resource management of the YRB changes in Q are mainly attributed to changes in catchment-specific parameter (n) and P. while E-p reduced Q in WYR and increased Q in WCR. These results indicated that the causes of trend of E-p rates, influenced by combined effects of radiative and aerodynamic variables should be explicitly explained using fully physically based E-p formulations. Additionally, in the water-limited YRB, changes of Q are primarily controlled by the changes in catchment conditions, and secondarily by hydroclimatic factors where the available water (P) rather than energy condition (E-p) is more important. Better understanding all of these relationships and how they have varied will help water resource management in a changing climate.

• 出版日期2012-9-25
• 单位CSIRO; 北京师范大学