Land Space Change Process and Its Eco-Environmental Effects in the Guanzhong Plain Urban Agglomeration of China

Urban agglomeration is the strategic core area of social-economic high-quality development in the world. However, high-density agglomeration and high-speed expansion have caused dramatic changes in land space, leading to prominent eco-environmental problems and, thus, threatening human well-being. How to solve the contradiction between urban agglomeration land expansion and eco-environment protection has become an urgent scientific problem. In this paper, we constructed a framework of assessing land space change and its eco-environmental effects in the urban agglomeration by using the Geo-informatic Graphic, eco-environmental quality index (EQI), and eco-environmental contribution rate. We then quantitatively analyzed the characteristics of land space transition as well as its eco-environmental effects in the Guanzhong Plain urban Agglomeration (GPUA) based on the land use data in 1990, 2000, 2010 and 2020. The results indicated that from 1990 to 2020, the production space of the GPUA continued to shrink, the living space continued to expand, and the ecological space showed a fluctuating increasing trend. There were significant regional differences in the land space change of the GPUA, with 92.2% of the counties showing a significant contraction in agricultural production space, 93.3% and 91.1% showing a significant expansion in urban and rural living space, and 64.4% showing an increase in woodland ecological space. Agricultural production space is transformed into ecological space and living space, and living space occupies ecological space and agricultural production space, which is the main mode of land space transition in the GPUA. With the continuous expansion of low-quality and high-quality areas of the eco-environment and the continuous contraction of medium-quality areas, the improvement and deterioration of the eco-environmental quality of the GPUA have coexisted, first showing a trend of deterioration and then improvement. The transition of agricultural production space into grassland and woodland ecological space improved the eco-environmental quality, while the transition of grassland ecological space into agricultural production space, and the occupation of agricultural production space by urban and rural living space as well as industrial and mining production space resulted in the deterioration of eco-environmental quality. The findings of this study may provide a theoretical basis for optimizing the allocation of land space resources in ecologically fragile urban agglomeration.