Geometric Clustering for the Consolidation of Farmland and Woodland
Geometric Clustering for the Consolidation of Farmland and Woodland
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农田林地整合的几何聚类
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
P. Gritzmann
中科院分区：
文献类型：
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作者：
S. Borgwardt;A. Brieden;P. Gritzmann
在许多农业地区，农民种植大量分散在扩展区域的小块土地。在德国巴伐利亚州的一个典型农业区，大约7 - 20名农民种植300至1000块土地;图1提供了典型分布的视觉印象。在这种情况下，农民面临严重的不利条件。由于个别地段分散在一个大的区域，有相当大的开销驾驶，导致人员和运输成本过剩。巴伐利亚州农业研究所的计算表明，这些额外的成本加起来往往超过农民来自农业生产的净收入的30%。（当然，欧盟和其他补贴构成了收入的一个相当大的额外部分，通常与成本效益生产的这些方面无关。此外，由于单个独立的地块相当小，现代重型机械无法有效使用。因此，种植的成本比同样总面积的更少、更大的地块要高得多。在其经典形式中，土地整理包括对农业地区的彻底重组，抛弃现有的土地结构，创造新的土地结构。这一过程涉及到长期的调查和新的法律的财产转让，因此成本高，时间长，而且不灵活。决定作出后，农民被迫参与这一进程。典型的传统土地整理过程持续十多年，每公顷成本约为2500欧元。当然，在农业地区，土地分配没有那么严格，那里的农民而不是土地所有者通过租借协议耕种了大部分土地。(This部分原因是继承规定，部分原因是小农经济状况坚韧。）因此，即使是在最近经历了经典形式的土地整理的地区，也可能看起来像破布地毯。这是北方巴伐利亚的一种常见情况。另一方面，租地耕种的农民通常与土地的联系较少，因此更愿意“交易”土地，以改善其经营的总体成本结构。这就有可能在现有地块结构的基础上达成概念简单的租借协定，即，而不会使财产结构无效。对于最佳再分配，有一些主要方面需要考虑。因为每个农民都希望拥有大片相连的土地，而土地结构，即，将该地区分割成单独的地块的做法没有改变，其目的是将相邻的地块分配给同一农民。当然，需要满足某些平衡约束。例如，在重新分配过程中，每个农民的土地总面积不应发生太大变化，土地质量、欧盟对其土地的补贴或其他可能的相关参数也不应发生太大变化。此外，生态限制也发挥了作用。特别是土壤的质量在该区域的不同地区通常是不同的。这意味着，在实践中，分配给每个农民的土地将形成某些相连的斑块，而这些斑块又应该尽可能靠近彼此。租借协议完全是自愿的。特别是，农民被允许修复他们的一些土地，
I nmany agricultural areas, farmers cultivate a large number of small lots that are scattered across an extended region. In a typical farming area in Bavaria, Germany, about 7 – 20 farmers cultivate between 300 and 1000 lots; Figure 1 provides a visual impression of a typical distribution. In such a situation, the farmers face serious disadvantages. Because the individual lots are scattered across a large region, there is considerable overhead driving, resulting in an excess of personal and transportation cost. Calculations of the Bavarian State Institute for Agriculture show that these additional costs often add up to more than 30% of the part of the farmers’ net income coming from their agricultural production. (EUand other subsidies that constitute a substantial additional part of the income are, of course, typically independent of such aspects of cost-efficient production.) Also, because the single separate lots are rather small, modern heavy machinery cannot be used profitably. Hence, the cost of cultivation is much higher than it would be for fewer, larger lots of the same total size. In its classical form, land consolidation consists of a complete restructuring of the agricultural area, discarding the current and creating a new lot structure. This process involves extended surveying and new legal assignments of property, and is hence costly, lengthy, and inflexible. After the decision is made, farmers are forced to participate in this process. A typical classical land consolidation process lasts more than a decade and costs about 2500 Euro per hectare. Of course, the land distribution is less rigid in agricultural areas where farmers other than the lot owners cultivate the majority of the lots, through lend–lease agreements. (This is partly causedby inheritance regulations and partly due to the tough economic situation of small farmers.) So, even districts that underwent a classical form of land consolidation in the recent pastmay look like rag rugs. This is a common situation in Northern Bavaria. On the other hand, a farmer who rents a lot for cultivation is generally less tied to the lot, and is hence more willing to ‘‘trade’’ it to improve the overall cost structure for his operations. This opens the possibility for conceptually simple lend–lease agreements based on the existing lot structure, i.e., without the nullification of the property structure. For an optimal redistribution there are some main aspects to be considered. Because large connected pieces of land are desirable for each farmer, while the lot structure, i.e., the dissection of the region into individual lots, is not changed, one aims to assign adjacent lots to the same farmer. Naturally, certain balancing constraints need to be satisfied. For instance, the total size of each farmer’s land should not change too much in the course of redistribution, neither should its quality of soil, the EU-subsidies attached to his lots, or other possibly relevant parameters. Also, ecological constraints play a role. The quality of soil, in particular, is typically different in different parts of the region. This means that, in practice, the assigned lots of each farmer will form certain connected patches, which, in turn, should be as close to each other as possible. The lend–lease agreements are completely voluntary. In particular, farmers are allowed to fix some of their lots