Interannual variability of regional evapotranspiration under precipitation extremes: A case study of the Youngsan River basin in Korea

作     者：Song, Youngkeun Ryu, Youngryel Jeon, Soohyun 

作者机构：Seoul Natl Univ Brain Korea Plus Team 21 Seoul 151921 South Korea Seoul Natl Univ Dept Landscape Architecture & Rural Syst Engn Seoul 151921 South Korea Seoul Natl Univ Interdisciplinary Program Agr & Forest Meteorol Seoul 151921 South Korea Seoul Natl Univ Interdisciplinary Program Landscape Architecture Seoul 151921 South Korea 

出 版 物：《JOURNAL OF HYDROLOGY》 (水文学杂志)

年 卷 期：2014年第519卷第PartD期

页      面：3531-3540页

核心收录：

学科分类：08[工学] 0708[理学-地球物理学] 081501[工学-水文学及水资源] 0815[工学-水利工程] 0814[工学-土木工程] 

基　　金：National Research Foundation of Korea (NRF) Korea government (MSIP) [2009-0083527] Korea-Americas Cooperation Program through the National Research Foundation of Korea (NRF) Korea Ministry of Education, Science and Technology [2011-0030485] BK21 Plus Project (Seoul National University Interdisciplinary Program in Landscape Architecture, Global leadership program towards innovative green infrastructure) Korea Meteorological Administration A3 program of National Research Foundation of Korea 

主　　题：Evapotranspiration Budyko curve Water balance MODIS Climate extremes 

摘      要：Understanding basin-scale evapotranspiration (ET) is an important issue for the management of regional water resources, especially with the recent trend of intensified precipitation (P). This study assessed the spatial and temporal variations of regional ET in response to P extremes, for various types of land-cover across the Youngsan River basin in Korea. The spatial distribution of monthly P and ET from 2001 to 2009 were estimated using rainfall records from 40 weather stations located across the basin and a satellite-derived, process-based ET model Breathing Earth System Simulator (BESS) (Ryu et al., 2011), respectively. The study periods were focused on the recent years with abnormally large, small and normal P, which were identified from anomalies in the z-sores of long-term (1973-2011) rainfall records. The variation of regional Er was assessed in terms of: (1) the controlling factors, using the statistics of related meteorological and geographical data, (2) a waterenergy balance, using Budyko s framework, and (3) the water balance of four selected watersheds in the region, using the partitioning of annual P into ET and riverflow discharge (Q). The total annual ET of this region decreased in abnorthally large-P year and increased in small-P year, because the ET in July to August (which accounts for more than 36% of annual ET) was limited by the available energy rather than available water due to the summer monsoon. In terms of land cover types, forests showed larger interannual variability in ET than paddy fields or cropland, with the differences in ET between large and small-P years being 108 and 82 mm yr(-1), respectively. The sensitivity of annual ET to P extremes was significantly related to the leaf area index (LAI), rather than soil properties, topography, or specific land-cover type (p 0.05, generalized linear model). However, the interannual variations of ET were not large (15-18%) compared to those of annual P (51-62%) and Q(108-232%) during 2002-20