| Taking Zhangye City,a typical city in northwest desert oasis area,as an example,this paper uses emergy theory to evaluate the sustainable and intensive use of cultivated land in the study area from meso city(county)scale and micro farmer scale,and expounds its spatial and temporal distribution characteristics,so as to put forward corresponding suggestions for the future development of sustainable and intensive use of cultivated land and related policy-making in the study area.This paper studies from the following three aspects:(1)Using emergy analysis method to measure the material input,output and intensive use of cultivated land system in Zhangye City from 2001 to 2019.(2)The evaluation index system of cultivated land sustainable intensive use was established,and the index of cultivated land sustainable intensive use was calculated.The dynamic analysis of cultivated land sustainable intensive use from 2001 to 2019 was carried out in time and space.(3)In the study area,300 households were selected to carry out a detailed household survey,and the emergy input,output and sustainable intensive use indicators were calculated in the process of cultivated land use with households as the unit.The sustainable intensive use level of cultivated land in the study area was evaluated from the perspective of household survey.(4)Combined with the temporal and spatial changes of cultivated land sustainable intensive use in 19 years and the current situation in 2019,the paper analyzes and puts forward policy suggestions.The results of the research are as follows:(1)In the past 19 years,the emergy input of cultivated land system in Zhangye City is on the rise,in which the proportion of non renewable industrial auxiliary energy is relatively large,indicating that high degree of agricultural mechanization has become the basic trend of agricultural development in the region;due to the uneven distribution of resources in the study area,the emergy input of each county is quite different in the development process;the internal structure of the system is uneven in the past 19 years It still has great development potential.(2)From the middle level of the city,this paper uses the method of emergy analysis to establish indicators to measure the level of cultivated land sustainable intensive use in Zhangye City.It is found that the cultivated land system in Zhangye city bears great environmental pressure.Based on the intensive degree,this paper divides the sustainable intensive utilization degree into three types in the study area: Category 1:non sustainable intensive utilization;category 2: sustainable intensive utilization;category 3: Sustainable non intensive utilization.Comprehensive analysis shows that the level of sustainable and intensive use of cultivated land in the study area is relatively low in the counties and districts in the past 19 years,and the cultivated land system as a whole is developing towards the type of non sustainable and intensive use.(3)From the micro scale of farmers,through the investigation of 300 farmers,using the method of emergy analysis to calculate the sustainable intensive use index of cultivated land based on household production activities,it is found that 83% of the farmers’ cultivated land use status is non sustainable intensive use in 2019,so the overall level of sustainable intensive use of cultivated land in the study area is not high. |
