Spatiotemporal Characteristics of Evapotranspiration Paradox and Impact Factors in China in the Period of 1960–2013

Huiping Huang,Heng Xiao,Yuping Han,Jinxi Song,Mingming Cao,Weili Cheng

doi:10.1155/2015/519207

Abstract

Downward trend of potential evaporation accompanied with upward of air temperature which is denoted as evaporation paradox has been reported in many regions over the past several decades in the world. In this paper, evaporation paradox and key factors attributed to ET0changes are systematically analyzed based on data from 599 meteorological stations during 1960–2013. Results show that (1) Evaporation paradox exists in all regions in1960–2013 and 1960–1999 except SWRB in 1960–2013 but no evaporation paradox in 2000–2013. (2) Evaporation paradox exists in large areas in spring and summer, the extent and range fall in autumn, and there is no evaporation paradox in winter. (3) The evaporation paradox area accounts for 73.7% of China in 1960–2013 and 91.2% in 1969–1999. (4) Sunshine hours, humidity, wind speed, and maximum temperature appear to be the most important variables which contributed to ET0change in China.

Highlights

Climate change characterized by global warming has been the focus of diversified research fields such as water resource, agriculture, ecosystem, and human health
There have been many discussions on methods of calculating ET0 (Penman [3], Hargreaves and Samani [4], Pereira and Pruitt [5]), the spatial-temporal variations (Irmak et al [6], Dinpashoh et al [7], Liang et al [8], Croitoru et al [9]), and its influencing factors (Feng et al [10], Liu and Yang [11], Harmsen et al [12], Tang et al [13]). Declining trends in both pan evaporation (McVicar et al [14]) and potential evaporation (ET0) have been reported to be occurring simultaneously in many regions with increasing trends of air temperature, which has been denoted as the evaporation paradox (Roderick and Farquhar [15]) and it has been one of the hot issues of hydrological system
In this paper observed meteorological variables are divided into two parts taking year 2000 as the boundary and the objectives of this study are (1) to investigate changes in ET0 and temperature in China since 1960s; (2) to examine the existence of evaporation paradox in different periods and regions; (3) to determine potential key factors attributed to ET0 changes in the whole country as well as different river basins

Summary

Introduction

Climate change characterized by global warming has been the focus of diversified research fields such as water resource, agriculture, ecosystem, and human health. There have been many discussions on methods of calculating ET0 (Penman [3], Hargreaves and Samani [4], Pereira and Pruitt [5]), the spatial-temporal variations (Irmak et al [6], Dinpashoh et al [7], Liang et al [8], Croitoru et al [9]), and its influencing factors (Feng et al [10], Liu and Yang [11], Harmsen et al [12], Tang et al [13]) Declining trends in both pan evaporation (McVicar et al [14]) and potential evaporation (ET0) have been reported to be occurring simultaneously in many regions with increasing trends of air temperature, which has been denoted as the evaporation paradox (Roderick and Farquhar [15]) and it has been one of the hot issues of hydrological system. In China both at national scale (Yin et al [25], Han et al [26]) and at regional scale such regions as the Northwest China (Liang et al [8]), the YeRB (Wang et al [27]), the HaRB (Xing et al [28]), the YaRB (Xu et al [29]), the Northwest

Objectives

Methods

Results