基于线性规划运输模型的农地整理权属调整

Land reallocation in farmland consolidation based on transportation model of linear programming

农地整理中的权属调整是缓解耕地破碎化最有效的工具之一,对农民意愿的忽视以及调整方法的不合理却阻碍着权属调整的推广。该研究以江西省黄玲乡农地整理项目为例,采用线性规划运输模型,以满足农户意愿为目标,进行权属调整,并将其与传统调整方法进行了比较。结果显示,基于线性规划运输模型的权属调整能够使地块数量减少71.71%,使地块与农居点距离减小7.16%,使75.04%的农民调整后的地块保留在调整前集中所在的田块,并在以上3方面以及调整精度上均优于传统方法;但是在减小地块分散程度上劣于传统方法;在调整效率上则与传统方法在不同阶段各有优劣。研究认为,基于线性规划运输模型的权属调整能够在缓解耕地破碎化的同时,最大程度地满足农民的意愿,具有良好的应用价值。目前,丰富权属调整方法体系,根据项目条件和农民偏好选择合适的方法,是促进权属调整大规模推广的有效途径。

Land reallocation in land consolidation is one of the most effective instruments to ameliorate farmland fragmentation. However, the unwillingness of farmers coupled with the inefficiency of reallocation method makes a great obstacle for promotion of it. Therefore, involvement of farmers＇ preferences and introduction of new technology with higher efficiency are necessary to get out of the plight. Taking farmland consolidation project in Huangling, Pengze county of Jiangxi province as a study area, in this paper, we constructed a new land reallocation model using transportation model of linear programming aiming at two main preferences of farmers in project area： to minimize the movement of land parcels and to minimize the distance between settlements and land parcels. Having determined the situated land blocks of land parcels, a land partitioning algorithm based on Python was proposed to realize the high efficiency and accuracy of the specific position, the area and shape determination of parcels. Also, a systematic comparison between this new model and the traditional one based on drawing lots was conducted in this paper from three aspects： 1） the amelioration of farmland fragmentation; 2） the change of parcels＇ location, and 3） the efficiency and accuracy of land reallocation. The results showed that both models can significantly reduce the number of land parcels, thus relieving land fragmentation. New model was slightly better than traditional one in terms of land parcels reducing while for those who still contracted more than one parcels after land reallocation, the spatial distribution resulted from new models was more scattered. In addition, the new model could reduce the average distance between land parcels and settlements in study area from 479.71 to 445.39 m, while it rose from 479.71 to 556.04 m in traditional model. For the change of location of land parcels, after land reallocation, 75.04% of land parcels in new model remained in the same land block prior to land reallocation, while only 31.06% of them remained in the same land block in the traditional model, attesting that linear programming guaranteed a high degree of meeting farmers＇ preferences. New model was more accurate compared to the traditional model. As for the efficiency, two models prevailed in different stages of land reallocation respectively. Traditional model was more efficient in land redistribution due to briefness of the procedure, while new model had significant high efficiency in land partitioning stage. It was concluded that the new model applying linear programming can well meet the needs of farmers, facilitating the promotion of land reallocation, especially in small scale land consolidation project. The introduction of GIS and computer programming also guaranteed the high accuracy and efficiency when compared to the way based on the experience and knowledge of experts. However, traditional model still had its applicable area, especially in places lacking of technical power and highly respected procedural justice. An abundant method system of land reallocation can make sure that the application of a specific model was based on the specific local condition, therefore, the development of new method was one of the key to promote large scale land reallocation in land consolidation.