Acta Geographica Sinica ›› 2006, Vol. 61 ›› Issue (7): 763-770.doi: 10.11821/xb200607010

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Quantificational Analysis on Eco-water Requirement of Plant-Soil Compound Ecosystem Based on GIS:A Case Study of Yan'an Region in Northwest China

WANG Lixia, REN Zhiyuan   

  1. College of Tourism and Environmental Sciences, Shaanxi Normal University, Xi'an 710062, China
  • Received:2006-01-12 Revised:2006-03-02 Online:2006-07-25 Published:2006-07-25
  • Supported by:

    National Natural Science Foundation of China, No.40371003; Innovation Foundation of Shaanxi Normal University


Although water has the central function of the bloodstream in the biosphere, especially in arid or semi-arid regions such as Yan'an region in Northwest China, yet very limited attention is paid to the role of the water-related processes in ecosystem. In this research, based on continuous 30-year weather condition report data and 10-year soil water content data in Yan'an region, using experiment models and field tests combined with GIS spatial analysis, a comparatively accurate method for measuring the minimum, moderate and maximum eco-water requirements of plant-soil compound ecosystem has been put forward. Additionally, the changing characters of eco-water requirement or scarcity have been addressed from spatio-temporal dimensions. The results show that: (1) The minimum eco-water requirement of plant-soil compound ecosystem in the study area is 21.6185 billion m3, and the corresponding scarcity is 2.3556 billion m3. (2) The landscapes presenting severe eco-water scarcity are conifer and broad-leaved mixed forest-loam, conifer-loam as well as deciduous and broad-leaved mixed forest-cohesive loam etc. The landscapes presenting eco-water budget balance are shrubby grass-cohesive loam, shrub-cohesive soil as well as grassland-sandy loam; and the landscapes presenting slight eco-water surplus are crop-cohesive loam, crop-sandy loam as well as crop-sand and gravel loam. (3) The areas with relative serious eco-water scarce problem are mainly located in the southwestern and central parts of Yan'an region on the hilly-gullied Loess Plateau, concentrating in summer or early autumn of the year.

Key words: Yan’an region, plant-soil compound ecosystem, eco-water requirement, spatio-temporal changes