基于两次平衡计算的南昌市耕作层土壤剥离再利用空间配置研究

研究目的:探讨耕作层土壤剥离再利用空间配置思路与方法,并以南昌市为例进行实证研究,为相关工作提供借鉴。研究方法:提出基于线性规划及OD成本矩阵方法的两次平衡计算的耕作层土壤剥离再利用土方空间配置思路。首先,确定剥离、覆土优先度并结合供求关系划定供需圈,在供需圈内部进行第一次调配平衡;其次,对于内部不能平衡的供需圈,进行第二次跨圈调配平衡,达到缩短运输距离,控制成本目的。研究结果:(1)南昌市耕作层剥离量能够满足覆土数量与质量的需求;(2)空间配置结果共划定18个供需圈,供需圈内土方调配加权平均运输距离为6 682 m,小于期望值10 km,满足项目实施要求;(3)共有15个供需圈存在土方量不平衡问题,跨圈调配的距离平均为72 071 m,满足短距离运输的要求。研究结论:以耕作层土壤剥离、覆土优先度及供求关系为基础划定供需圈,基于线性规划及OD成本矩阵的两次平衡计算的空间配置思路与方法,可以优化运输距离,减少运输成本,提高项目实施效益。本文提出的空间配置思路可以为耕作层剥离再利用工程的顺利实施提供理论与方法借鉴。

Study on Spatial Allocation of Soil Stripping and Reutilization in Arable Layer in Nanchang City Based on Two Balance Processes

The purpose of this paper is to improve the theory and methodology of spatial allocation of surface soil layer stripping and reutilization in arable layer in order to provide some references for the relative work, taking Nanchang City as a case. The methods of this paper are as follows. Based on linear programming and cost of OD (origin-destination) matrix method, two steps of balance calculation were applied to optimize surface soil layer reutilization. Firstly, priority of stripping surface soil layer and earthing were classified and the supply and demand circles were determined, in which the earth volume of the surface soil layer was balanced. Secondly, cross-circle balance was realized among the earth volume unbalanced circles. After the two steps of balance, the transport distance and the transportation expenses are expected to be minimized. The results are as follows. 1)The calculation results indicate that the stripping earth volume can satisfy the needs of earthing in Nanchang City. 2)A total of 18 supply and demand balance circles were determined for spatial allocation. The weighted average transport distance among supply and demand circles is 6 682 m, shorter than 10 km required by project implementation. 3)Totally, 15 within 18 demand-supply circles cannot balance earth volume within themselves. The optimized transport distance is 43 908 m, which can well shorten the transportation distance. In conclusion, the proposed two steps earth volume spatial allocation ideology and methodology based on linear programming and OD cost matrix can optimize the transportation distance, reduce the transportation costs and improve the benefits. This study can provide some references for the work of surface soil layer stripping and reutilization.