Journal of Geographical Sciences ›› 2008, Vol. 18 ›› Issue (1): 107-114.doi: 10.1007/s11442-008-0107-4

• Climate and Environmental Change • Previous Articles     Next Articles

Spatial-temporal differences in in-stream flow requirement based on GIS: A case study of Yan’an region, northern Shaanxi

WANG Lixia, REN Zhiyuan   

  1. College of Tourism and Environmental Sciences, Shaanxi Normal University, Xi’an 710062, China
  • Received:2007-04-05 Revised:2007-08-08 Online:2008-02-25 Published:2008-02-25
  • Supported by:

    National Natural Science Foundation of China, No.40771019; Innovation Foundation of Shaanxi Normal University

Abstract:

Although water has the central function of the bloodstream in the biosphere espe-cially in arid or semi-arid regions such as Yan’an region in northwestern China, yet the very limited attention is paid to the role of the water-related processes in ecosystem. In this re-search, based on continuous nearly 50-year data including runoff volume, sediment discharge as well as sediment accretion from hydrographic stations, and 10-year information of water quality from pollution monitoring stations, the method for measuring in-stream flow require-ment has been put forward supported by experiential models and GIS spatial analysis. Addi-tionally, the changes of in-stream flow requirement for environment and economic develop-ment have been addressed from spatial-temporal dimensions. The results show that: (1) According to the central streams in Yan’an region, mean annual in-stream flow requirement reaches 1.0619 billion m3, and the surface water for economic exploitation is 0.2445 billion m3. (2) Mean annual in-stream flow requirement for sediment transfers in flood period occupies over 80% of the integrated volume in a year. (3) From the 1950s to 1970s, in-stream flow requirement for sediment transfers is comparatively higher, while from the 1980s to 1990s, this requirement presents a decreasing tendency.

Key words: GIS spatial analysis, Yan’an region, in-stream flow requirement, spatial-temporal differences