DOI: 10.1038/ngeo2514
论文题名: Rainfall consistently enhanced around the Gezira Scheme in East Africa due to irrigation
作者: Alter R.E. ; Im E.-S. ; Eltahir E.A.B.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2015
卷: 8, 期: 10 起始页码: 763
结束页码: 767
语种: 英语
Scopus关键词: air temperature
; climate modeling
; irrigation system
; land cover
; land use change
; numerical model
; precipitation (climatology)
; regional climate
; streamflow
; Gezira
; Sahel [Sub-Saharan Africa]
; Sudan
英文摘要: Land-use and land-cover changes have significantly modified regional climate patterns around the world. In particular, the rapid development of large-scale cropland irrigation over the past century has been investigated in relation to possible modification of regional rainfall. In regional climate simulations of the West African Sahel, hypothetical large-scale irrigation schemes inhibit rainfall over irrigated areas but enhance rainfall remotely. However, the simulated influence of large-scale irrigation schemes on precipitation patterns cannot be substantiated without direct comparison to observations. Here we present two complementary analyses: numerical simulations using a regional climate model over an actual, large-scale irrigation scheme in the East African Sahel-the Gezira Scheme-and observational analyses over the same area. The simulations suggest that irrigation inhibits rainfall over the Gezira Scheme and enhances rainfall to the east. Observational analyses of rainfall, temperature and streamflow in the same region support the simulated results. The findings are consistent with a mechanistic framework in which irrigation decreases surface air temperature, causing atmospheric subsidence over the irrigated area and clockwise wind anomalies (in background southwesterly winds) that increase upward vertical motion to the east. We conclude that irrigation development can consistently modify rainfall patterns in and around irrigated areas, warranting further examination of potential agricultural, hydrologic and economic implications. © 2015 Macmillan Publishers Limited. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106159
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Ralph M. Parsons Laboratory, Massachusetts Institute of Technology, Cambridge, MA, United States; Center for Environmental Sensing and Modeling, Singapore-Massachusetts Institute of Technology Alliance for Research and Technology, Singapore, Singapore
Recommended Citation:
Alter R.E.,Im E.-S.,Eltahir E.A.B.. Rainfall consistently enhanced around the Gezira Scheme in East Africa due to irrigation[J]. Nature Geoscience,2015-01-01,8(10)