Spatio-temporal pattern and its influencing factors of coordinated development of man-land relationship in China using PSR model

Scientific cognition of the interactive relationship between man and land is an important basis to realize the coordinated development of the man-land relationship. In this study, the PSR (Press-State-Response) theoretical system was established to investigate the spatio-temporal pattern and the influencing factors in the coordinated development of the man-land relationship in China. Human activities posed great pressure on the regional environment and thereby aggravated the contradiction between man and land. At the same time, the man-land relationship was formed in the man-land interaction and fed back to human activities. Then, an adaptive system between man and land was formed after positive (or negative) response measures to improve (or worsen) the man-land relationship. The PSR evaluation index system was thus constructed on the basis of the theoretical system. The cross-sectional data were selected from different provinces of China in 2002, 2007, 2012, and 2017. The results showed that: 1) There was a relatively stable level of coordinated development in the man-land relationship in China from 2002 to 2017, generally between moderate and good coordination. However, the value of coordination degree was in a V shape trend, which decreased from 0.648 to 0.494 in 2002-2007, and then rose to 0.639 in 2012, and further increased to 0.705 in 2017. There was also a development process of “tightening first and then easing” in the man-land relationship over the past 15 years. 2) There was also an obvious increase in the regional differences for the coordination of man-land relations from the perspective of space. The coordination of the man-land relationship in western provinces generally decreased, and that in eastern and central regions improved, while those in northeast regions remained relatively stable. At present, it mainly showed the spatial distribution characteristics of higher coordination degree in the eastern, northeast, and central region, whereas the lower coordination degree in the western region. 3) The geographic detector analysis showed that there were different factors influencing the coordination of the man-land relationship among the eastern, central, and western regions. Specifically, the leading influencing factors in eastern China were as follows: Population density, pesticide usage per unit cultivated land area, per capita cultivated land area, the proportion of industrial output value to GDP, per capita industrial wastewater discharge, the popularization rate of harmless sanitary toilets in rural areas, and per capita water resources. The leading influencing factors in central China were: Forest coverage rate, proportion of crops affected area to total cultivated land area, population density, per capita water resources, urban water-saving rate, and proportion of crops affected area to total cultivated land area, and fertilizer application amount per unit cultivated land area. There were five leading influencing factors in western China, including per capita arable land area, effective irrigation rate of arable land, per capita industrial wastewater discharge, the proportion of industrial output value to GDP, and the popularization rate of harmless sanitary toilets in rural areas. Each region should take the coordinated development of man and land as the criterion during this time, thereby implementing different control measures according to the local physical and geographical conditions and promoting economic and social development. Human activities needed to be standardized in utilizing and transforming nature, thereby promoting the coordinated and sustainable development of the man-land system.