GIS-based evaluation and analysis of land ecological quality and limiting factors: A case study of the city of Sanmenxia

摘要

Ecological quality assessment is a scientific basis for land sustainability and rational planning of regional land.In this paper,we developed indexing systems to assess land ecological quality from four aspects using administrative village as assessing unit in the city of Sanmenxia.The four aspects were fundamental ecological condition,structural conditions,pollution,destruction and degradation,and ecological protection effect.The ecological quality was evaluated based on GIS technology and the weight sum model.The factors limiting the ecological quality were identified based on index deviation and obstacle degree.The results show that the land quality of the city was distinctly varied,with excellent quality in the Shan county.Followed by Mianchi county,and Lushi county and Yima city.The quality in the Lake District was at the middle level,most areas of Lingbao city were fair,and was poor in the town of Chuankou of Lingbao.The reasons were caused by land ecological natural fundamental and ecological protection.Our study further shows that the major limiting factors are the effective thickness of soil,acreage of forest and plantation,acreage of high quality and non-polluted arable land,average annual precipitation and regional environmental quality.