Acta Geographica Sinica ›› 2010, Vol. 65 ›› Issue (11): 1355-1362.doi: 10.11821/xb201011005

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Variations of Agricultural Water Requirements in Lancang River Basin in Last 50 Years

GU Shixiang1,2, HE Daming3, CUI Yuanlai1, LI Yuanhua4   

  1. 1. State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China;

    2. Yunnan Institute for Investigation, Design and Research of Water Resources & Hydropower Engineering, Kunming 650021, China;
    3. Asian International Rivers Center, Yunnan University, Kunming 650091, China;

    4. Department of Irrigation, Drainage and Rural Water Supply, MWR, P.R.China, Beijing 100053, China
  • Received:2010-04-26 Revised:2010-08-06 Online:2010-11-20 Published:2011-01-03
  • Supported by:

    Key Project of Chinese National Programs for Fundamental Research and Development (973 Program), No.2003CB415105; Special Research on Comprehensive Planning of Water Resource in Yunnan Province, No.YSZY-2003-01

Abstract:

Weather data of 8 meteorologic stations in the Lancang River Basin from the 1950s to 2007 and current cropping pattern, field water moisture management, etc., were collected and used to investigate changes in humidity and crop irrigation water requirements using Mann-Kendall and the Rescaled Range Analysis methods. The results show that in the whole basin, annual and dry-season average temperatures significantly increased, and dry-season rainfall increased while wet-season rainfall decreased. Evaportranspiration (ET0) increased during both dry and wet seasons at all the stations except Dali, Jianchuan and Gengma, and the aridity-humidity index decreased at most stations. The turning points of weather factors, ET0, the aridity-humidity index, paddy irrigation requirements and total agricultural water requirements occurred from the 1960s to the 1990s. The spatial changing tendency of paddy irrigation quota increased with the increase of altitude and latitude, and the coorelation coefficients are 0.513 and 0.610, respectively. The maximum value inWeixi, while the minimum in Mengla.

Key words: agricultural irrigation quota, Lancang River, the Longitudinal Range-Gorge Region