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| Variation of land utilization and its ecological effectiveness in wind-water erosion cross region of northern Shaanxi |
| Meng Qingxiang1,2,Liu Guobin2,Yang Qinke2 |
| 1.College of Resources & Environment,Henan Agriculture University,450002,Zhengzhou;2.Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,712100,Yangling,Shaanxi: China |
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Abstract Based on GIS,temporal and spatial variation of land utilization in wind-water erosion cross region of northern Shaanxi from 1986 to 1997 was analyzed.Land utilization condition in future was forecasted by Markov Model,and variation of land utilization and its ecological effectiveness were investigated by ecological elastic limit.The results indicated that the main variation of land utilization is the increase of irrigated fields,dry farming field,other forest land,grassland with high coverage,water body and constructive land,and other area of land utilization showed a direction of reducing.Annual average dynamic variation index of land utilization was 2.4%,and dynamic variation range of land utilization is higher sharply than that of absolute value.The conversion within land utilization type was acute strongly.The vertical centroid of land utilization type was descending,except irrigated fields,grassland with high coverage,and other grassland.The ecological elastic limit showed downtrend wholly,but whose decreasing range was lessen.
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Received: 31 October 2005
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