JOURNAL OF NATURAL RESOURCES ›› 2014, Vol. 29 ›› Issue (12): 2023-2035.doi: 10.11849/zrzyxb.2014.12.004

• Resource Ecology • Previous Articles     Next Articles

Eco-risk Analysis of Oasis Region Based on Landscape Structure and Spatial Statistics Method—A Case Study of Wuwei and Minqin Oases

WEI Wei1, SHI Pei-ji1, LEI Li2, ZHOU Jun-ju1, XIE Bin-bin3   

  1. 1. College of Geographical and Environment Science, Northwest Normal University, Lanzhou 730070, China;
    2. Management Bureau of Shiyang River Basin, Gansu Provincial Department of Water Resources, Wuwei 733000, China;
    3. School of Urban Economics and Tourism Culture, Lanzhou City University, Lanzhou 730070, China
  • Received:2013-10-21 Revised:2014-02-25 Online:2014-12-20 Published:2014-12-20
  • About author:Resource Ecology

Abstract:

Eco-risk assessment is a hotspot arising in recent 20 years, due to the spatial heterogeneity and the complexity in assessment, as well as an integrated junction for geography, ecology, and environment risk evaluation. The study of ecological risk is helpful for understanding local ecological environment, reducing ecological risk, and finally improving the interactions between human beings and nature. To reveal the impact of ecological risk of oasis change in the small watershed of the Shiyang River Basin, Wuwei and Minqin oases were chosen as the study area. Landscape information was obtained from satellite remote sensing TM images of 1987, 2000 and 2010. The grid by 4 km×4 km was created as the auxiliary evaluation unit, and the GIS technology was employed as the data integration analysis platform. In order to generate the map of oasis eco-risk in 1987, 2000 and 2010, the spatial overlay method was used to make the index a spatial variable. Besides, the landscape interference index, fragile landscape degree, landscape dominance index and fragmentation index were used to analyze the relationship between landscape pattern and the eco- risk degree through the supporting of ArcGIS 10.0, ArcView 3.2 and FRAGSTATS softwares. Besides, based on the overlay analysis of every netfish of the landscape index, the eco-risk degree was reflected by spatial expression. Meanwhile, the spatial statistic method was also used to analyze the spatio-temporal process of landscape structures and ecological risk. The results showed that: 1) the urban and rural land expanded rapidly from 1987 to 2010. At the same time, the farmland and grassland decreased at a large scale, and the preponderant landscape changed from farmland and grassland to farmland and construction land. 2) The Wuwei oasis ecological risk has experienced the transition from high to moderate change, and the ecological risk as a whole tended to be better while the Minqin oasis eco-risk turned from medium /higher- risk to higher- risk/highest- risk. The ecological risk of the whole study area was deteriorated in the past 20 years. 3) The Wuwei oasis elements mainly tended to cluster and its value was higher than the average. It showed the low eco- risk area was much more clustered, and the trend was increasing. Comparatively, the elements of Minqin oasis that were lower than the average tended to be clustered, the high eco-risk area clustered extremely. It also showed that the cluster characteristics increased in area and expanded in space. Therefore, Wuwei oasis should expand the scale of the facilities of agriculture or high-efficiency water saving. At the same time, the ecological key factors such as forest for conservation of water supply and alpine grassland should be protected. What's more, desertification governance in Minqin oasis is particularly important. Through the grass square, cotton stem, corn straw, drought-tolerant plants can effectively manage desertification, and improve the resistance of eco-environmental change.

Key words: ecological risk, oasis region, landscape structure, Shiyang River Basin, spatial statistics

CLC Number: 

  • X820.4