Field investigation of actual conditions and characteristics of stone walls in farm land

Abstract

In order to grasp the actual condition and the characteristics of stone walls in farm land, firstly ambiguous terms regarding stone walls were clearly redefined and secondly field investigations and interviews were conducted at the twelve selected regions in western Japan where there are terrace fields with stone walls. In the study regions, the farm land stone walls were made with locally produced stones with the intention of ensuring larger farmland in steeply sloping areas. The farmland stone walls were mainly constructed by dry rough masonry with boulder stones or broken stones. Though typical characteristics of masonry in each study region could be grasped, the features of the masonry were quite diverse within a study region because of difference of time from the construction or restoration work. Comparing the typical profile of farm land stone walls with that of road side stone walls, differences in the slope gradient, the materials and the amount of back filling, and the foundation structure were observed.