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

土地改良工程不仅具有增加农业生产、减少劳动力投入等直接效应，而且具有稳定粮食供应、降低成本、促进区域经济发展等间接效应。探索一种综合评价直接效应和间接效应的方法，是本研究的主题。这些效应是由农业结构和区域经济等多种因素共同作用产生的。因此，我将这些多重交互理解为一个复杂的系统，并根据系统动力学建模，通过仿真对真实系统进行建模。在此研究之前，我已经构建了东川灌溉工程和田原地区农田调整的基本模型。因此，我对安知县和三久县的农田调整和津河西武地区的建设项目农田进行了新的调查。然后，通过这些新的调查，我增加了对基础模型的修改，并能够构建具有高应用性的SD模型。我衡量了农业生产、区域工业、人口、劳动人口、资源利用和地方政府财政六个部门的影响。根据上面的效果分析，如果我们使用我改进的SD模型，我们将能够测量和评估多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.