[Comparison on driving mechanism of county ecological efficiency: With three counties in the mountainous area of southern Ningxia, China as an example]. / 县域生态效率驱动机制对比­­ä»¥å®å—山区3县为例.

ABSTRACT

With Tongxin, Xiji, and Longde counties in the mountainous area of southern Ningxia as the research area, we used extended-exergy analysis (EEA) to compare their ecological efficiency driving mechanism in 2008-2017 to explore the causes of their variation in ecological degradation. The results showed that the overall difference of ecological efficiency in the three counties was significant during the study period. The ecological efficiency of Tongxin was low, with large inter-annual variation. The ecological efficiency of Xiji was stable, and the overall efficiency of Longde was the highest. The difference of exergy scale was small among the three counties. The exergy proportion in the economic sectors was not coordinated, which were dominated by agricultural and residential sectors. The economic sectors presented significant capital-pull-type and labor-intensive characteristics, indicating the driving force for ecological degradation mainly came from agricultural production and residents' lives in underdeveloped regions. The system's internal exergy conversion rate and the external energy exchange rate of the three counties were extremely low, constituting a simple network circulation path with high input, low storage, low opening and low conversion, which weakened the endogenous development of social economic subsystem and threatened the fragile ecosystem.