ため池の減少率を規定する土地利用変化 : 愛知県知多半島中部の事例 Variation in the Rate of Disappearance of Irrigation Ponds Based on Land Use : A Case Study in the Central Part of the Chita Peninsula, Aichi Prefecture
There are several irrigation ponds in the city of Handa and the town of Agui, central areas on the Chita peninsula, Aichi Prefecture. Recently, those irrigation ponds have been decreasing in number. The cause and the manner in which these ponds had been disappearing were clarified by focusing on the spatial variation in the decrease rate based on land uses.<br> The study methods adopted were as follows: the study area was divided into 500-m grid cells and classified according to their dominated land use. The author also verified in the field all the irrigation ponds that were recorded in the "Irrigation Pond Ledger" (a survey carried out by Aichi Prefecture in 1998) of the study area. Further, the number of irrigation ponds was counted and the ponds that had disappeared in every grid cell were recorded. The disappearance rate of irrigation ponds for every land use category was calculated and these rates were compared.<br> Most of the irrigation ponds in this area existed on farmland on which land consolidation had not been undertaken or farmland consisting of many scattered artificial constructions. The irrigation ponds in these land use areas had low capacity, small irrigation area and a high disappearance rate. On the other hand, there were few irrigation ponds on residential land and farmland on which land consolidation had been undertaken. The irrigation ponds in these land use areas had relatively high capacity and large irrigation area, and their disappearance rate was low. The following conclusions can be drawn on the basis of these results:<br>1) In areas where land development had not been undertaken, the value of small-sized irrigation ponds decreased; hence, they were abandoned and they disappeared.<br>2) During the land development of residential land and new farmland, small irrigation ponds were destroyed. However, large irrigation ponds were left and maintained. On completion of the land development process, most of these large irrigation ponds were utilized for purposes other than the original ones.
地理学評論 79(6), 335-346, 2006-05-01
The Association of Japanese Geographers