Change of farming radius of relocated villages and its influence in coal mining subsidence areas

Abstract: Huainan City is a typical city of the overlapped area of crop and coal production, and coal mining subsidence is typical in the country, this paper took the mining subsidence area of Huainan City as the research object, and discussed the change characteristics of the actual farming radius after village relocation in the subsidence area and its impact on agricultural production. It mainly studied the changes in the agricultural production convenience, the mode of labor and the enthusiasm of production activities caused by the change of farming radius, and the adverse effects brought by it. Firstly, based on regular "Equal" method, we calculated the spatial farm radius before and after the village relocation in the subsidence area from 2010 to 2015, which represented only the spatial distance and needs to be corrected. And then based on the DEM data of Huainan City, the relief amplitude of the study area was analyzed and the best statistical unit for calculating the relief amplitude value of Huainan City was determined, and the topographic correction coefficient of the farming radius of Huainan City was calculated based on the unit. According to the cultivated land area in the land ownership area, the regional reclamation index was calculated. Then, the topographic landform and agricultural land layout of the spatial farming radius was quantitatively corrected by using the topographic correction coefficient of the farming radius and reclamation index to obtain the actual farming radius, and the change characteristics of the actual farming radius after village relocation in subsided areas were analyzed. Finally, based on the calculation results of actual farming radius, combined with the field questionnaire survey, the impact of farming radius on agricultural production was analyzed from the aspects of farming convenience and agricultural labor, and corresponding countermeasures and suggestions were put forward. The results showed that: 1) the best statistical unit for extracting relief amplitude in Huainan City based on 30 m by 30 m GDEM DEM data was 120 m by 120 m, and the topographic correction coefficient of the farm radius of rural settlements was 1.052 based on the unit. 2) Due to the impact of coal mining, the ground collapsed, forming sporadic water accumulation areas, increasing the fragmentation of cultivated land and reducing the effective cultivated land ratio, therefore, the reclamation index of the land in which the village was relocated in 2015 was decreased compared to 2010. 3) Through the mathematical model of farming radius, the actual farming radius before and after the village relocation in the coal mining subsidence area was calculated, compared with the farming radius before relocation, the actual farming radius after the village relocation of the coal mining subsidence area had expanded by 1~20 times. Among the villages, those moved to Phoenix lake new village had the highest increase in the farming radius, increasing by 22 540.45 m. The villages relocated to Liulongxin village had the smallest increase in the farming radius, increasing by 914.05 m. 4) By converting actual farming distance into time, we compared the time before and after relocation for farming. Before relocation, it only took 9-24 minutes on foot for farming. However, after relocation it was 20-296 minutes, indicating that the time spent on the road has increased dramatically. In order to reduce the time spent on road, farmers have to update their transportation or reduce the number of round trips, which would directly lower the convenience of farmers farming and may weaken the enthusiasm of farmers in agricultural production activities. Through questionnaire survey, we found that the agricultural population had decreased after the relocation, and increasing farming radius led to more farmers give up agricultural production. The agricultural labor force gradually shifted to non-agricultural industries and towns, causing the farmland to be barren, which is not conducive to the sustainable development of agriculture. 5) In order to reduce the adverse impact of increased farming radius on agricultural production, the local government and relevant departments should take corresponding measures: implementing effective and reasonable relocation of mining villages; increasing agricultural support; strengthening agricultural scale operation and accelerating agricultural mechanization production.