JOURNAL OF NATURAL RESOURCES ›› 2015, Vol. 30 ›› Issue (4): 580-590.doi: 10.11849/zrzyxb.2015.04.005

• Resource Ecology • Previous Articles     Next Articles

Landscape Ecological Risk Assessment of Farming-Pastoral Ecozone Based on Land Use Change —A Case Study of the YangheWatershed, China

XU Lan1,2, LUO Wei2, ZHOU Bao-tong1   

  1. 1. School of Geography sciences, Southwest University, Chongqing 400715, China;
    2. State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, CAS, Beijing 100085, China
  • Received:2014-03-14 Revised:2014-10-11 Online:2015-04-20 Published:2015-04-16

Abstract:

To reveal the impact of land use change on ecological risk, dynamic changes of land uses in the Yanghe Watershed which is a typical farming-pastoral ecozone in north China were analyzed with ArcGIS technologies based on remote sensing and land use data during 1990- 2008. The Yanghe Watershed was divided into 525 ecological risk assessment units based on the theory of landscape ecology. A temporal and spatial model of ecological risk assessment in the study area was established based on land use changes and landscape structures. Results showed that the areas of farmland and grassland accounted for more than 67% of total area of the watershed. Generally, landscape ecological risk indicated by ecological assessment index (ERI) for the whole watershed increased from 0.1973 to 0.2384 during 1990 to 2008. The area for the lowest (ERI≤0.17) and the highest (ERI >0.68) ecological risks reduced by 3.53% and 0.43%, respectively, while the areas of the lower (0.17< ERI≤0.26), the medium (0.26< ERI≤0.42)and the higher (0.42< ERI≤0.68) ecological risks increased. Distributions of five ecological risk grades were relatively concentrated. The sites with the relative high risk grade (ERI >0.26) were located along the main streams and sub- streams of the Yanghe Watershed, while those with the lower risk (ERI≤0.26) were further away from these streams.

Key words: land use change, farming-pastoral ecozone, ecological risk, the Yanghe Watershed

CLC Number: 

  • X171.1