Study on System Analysis to the Economic Effects of Land Improvement Projects.

土地整治工程不仅具有增加农业产量、减少投入劳动力等直接效应，而且还具有稳定粮食供应、降低成本、促进区域经济发展等间接效应。本研究的目的是探索一种综合评价直接效应和间接效应的方法，是在农业结构和区域经济诸因素相互作用下产生的。因此，笔者将这些相互作用理解为一个复杂系统，并根据系统动力学建模方法，对真实的系统进行了模拟。在本研究之前，笔者已经构建了丰川水利工程和田原地区农田整理的基本模型。因此，我重新调查了安城中部地区和三久茂南部地区的农田调整，以及津马岛西武地区的建设项目农田。在此基础上，通过对基本模型的改进，构建了应用性较强的SD模型，并对农业生产、区域产业、人口、劳动人口、资源利用、地方财政等六个部门的影响进行了测算，根据上述影响分析，如果利用改进后的SD模型，我们将能够测量和评估各种土地改良项目的各种效果。

Project of land improvement usually produces not only the direct effects which are the increasing agricultural production and the decreasing input labour-force, etc, but also the indirect effects which are the stabilization of food supply, cost down, and further the development of regional economy,etc. It is the subject in this study that we explore a method to evaluate synthetically the direct effects and the indirect effects.Those effects are produced under the interaction of various factors which are made up of the agricultural structure and the regional economy. Therefore I understand those multi-interasctions as an complex system, and according to the System Dynamics Modeling, I modeled the complex system on the real system by simulation.Before this study, I had constructed the basic model for the Toyokawa irrigation project and the readjustment of farmland in the Tahara district. So I had new investigation for the readjustment of farmland in the Anjyo-chyubu district and Mikumo-Nanbu district,and the construction project farmland in Tsumagoi-Seibu district. Then I added to modify the basic model by these new investigation, and was able to construct the SD model with high application.I measured the effects in the six sectors, that is,agricultural production, regional industry, population, working population, resource use, and local goverment finance.according to the above effect analysis, if we will make use of the SD model which I had improved, we will be able to measure and evaluate the various effects on many kinds of project of land improvement.