[1]LIU Di,CHEN Hai,ZHANG Min,et al.Analysis of Spatial-temporal Distribution of Landscape Ecological Risk in Ecologically Vulnerable Areas and Its Terrain Gradient—A Case Study of Mizhi County of Shaanxi Province.[J].Research of Soil and Water Conservation,2019,26(04):239-244,251.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
26
Number of periods:
2019 04
Page number:
239-244,251
Column:
Public date:
2019-06-11
- Title:
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Analysis of Spatial-temporal Distribution of Landscape Ecological Risk in Ecologically Vulnerable Areas and Its Terrain Gradient—A Case Study of Mizhi County of Shaanxi Province.
- Author(s):
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LIU Di1,2, CHEN Hai1,2, ZHANG Min1,2, SHANG Shuhan1,2, LIANG Xiaoying1,2
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1. College of Urban and Environmental Sciences, Northwest University, Xi’an 710127, China;
2. Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, Xi’an 710127, China
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- Keywords:
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landscape ecological risk; spatial-temporal distribution; terrain gradient; Mizhi County; ecologically fragile areas
- CLC:
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X171
- DOI:
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- Abstract:
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Ecologically fragile area has become one of the hot spots of landscape ecological risk assessment research. Taking Mizhi County of Shaanxi Province in the Loess Plateau as research area, we divided the land-use types into seven types, including farmland, orchard, forests, grassland, water body, construction land and wasteland, with the help of the land-use pattern data in 2009 and 2015. The spatial-temporal distribution of ecological risk was analyzed through the ecological risk model integrated the interference degree and the vulnerability degree. The distribution of ecological risk under the terrain gradient was revealed by the terrain distribution index. Several conclusions were drawn as the follows. (1) The land-use pattern in Mizhi County had experienced considerable changes. The area of farmland decreased by 3 168.45 hm2, while forestland and wasteland increased by 1 102.95 hm2 and 1 609.47 hm2, respectively. (2) The integrated ecological risk index increased from 0.221 7 in 2009 to 0.228 9 in 2015. The spatial distribution pattern of ecological risk was higher in the west than in the east as well as the middle was higher than the north and south. The grade Ⅰ risk was mainly converted to grade Ⅱ risk, and the area ratio was reduced from 28.17% to 13.59%. The grade Ⅲ risk reached 1/3 of the area of the research area, which was mainly transformed from the grade Ⅱ risk. The grade Ⅳ and Ⅴ risk area changes were limited, and the area ratio increased by 3.9%. (3) The spatial-temporal distribution of landscape ecological risk was presented on the trend of terrain distribution index clearly. The trend of gradeⅠrisk shifting to low altitude and low slope was obvious, and both grade Ⅱ and Ⅲ risk were transferred to high altitude. There was no obvious risk transfer phenomenon of grade Ⅳ and Ⅴ risk on the terrain gradients.