Complex network and redundancy analysis of spatial–temporal dynamic changes and driving forces behind changes in oases within the Tarim Basin in northwestern China

Abstract

Oases serve as the material basis for human survival and development in arid areas, and thus monitoring their spatial–temporal dynamic changes is of theoretical and practical significance. In this study, a four-stage oasis dynamic change network model was constructed, based on the complex network method, to analyze oases dynamic changes within the Tarim Basin located in northwestern China from 1990 to 2018. Network indicators, such as the degree value, betweenness centrality, and average path length were calculated to identify key land types and transformation processes, and to discuss the stability of oasis systems. This method provided a process analysis with statistical metrics and more information than the traditional methods to reveal the spatial–temporal dynamic change process of oases. In addition, seven social and economic indicators were selected to analyze the driving force behind oasis dynamic change through detrended correspondence analysis and redundant analysis. Our results showed that the total and artificial oases areas increased, but the natural oases area decreased, during 1990 to 2018. Cultivated land and natural grassland played a key role in oasis dynamic change. The conversion between various nodes in the network became simpler and the oases systems became increasingly unstable with time. The urbanization and industrialization factors prompted the conversion of cultivated land and unutilized land to construction land, and economic indicators were the driving forces for the expansion of cultivated land. In summary, in order to establish a harmonious symbiotic relationship between humans and the natural environment, it is necessary to effectively control the scale of artificial oases conversion and protect the benign development of natural oases. Prohibiting excessive reclamation of cultivated land, returning unstable cultivated land to grassland for saving water, and governing degraded grassland were suggested to realize the sustainable oasis development.