On the Noto Peninsula, following the “Reiwa 6th year Noto Peninsula Earthquake,” river flooding and sediment disasters occurred due to record-breaking heavy rains on September 21. Before the flood I visited Suzu City and Wajima City for the “House Damage Certification Survey,” and the place I went about 3 months ago was flooded.
Incidentally, at the end of August this year, due to the heavy guerrilla rain that occurred in western Kanagawa prefecture, even in Hiratsuka city where my parents' house is located, the 72-hour rainfall reached 394.0 mm, the highest in the history of observations, and river flooding and inland flooding occurred. Close to my parents' house, around the Ninomiya-cho Legal Affairs Bureau area, which I often visit for appraisal work, river flooding occurred, the road in front of my parents' house was also flooded about 30 cm, and air bubbles were blowing out of the sewage handhole cover.
The heavy guerrilla rain in western Kanagawa was said to be the highest rainfall in the history of observations, when I was in elementary school, even during the typhoon, there was rainfall close to the current heavy rain, but I don't remember that inland flooding occurred where the front road became a “pond.”
So why did it lead to river flooding and inland flooding?
when I was in elementary school, many “fields” of rice paddies, farmlands, etc. were seen next to the school route, but now in Reiwa, those paddy and farmlands have been replaced by residential sites where buildings are built up to the entire site. Also, in Hadano City, which is located upstream of the river that flows close to my parents' house and is famous for "Tobacco Festival", there are no tobacco fields anymore, peanut fields have also been converted to residential land, so the land that used to be a field is being used as a residential site.
In addition to a short period of time and large amounts of rainfall due to heavy guerrilla rainfall, the number of fields with water retention functions has drastically decreased due to residential land development, leading to a drastic decline in water retention function, and the fact that rainwater can not penetrate the ground and flows into rivers in a short time seems to be a major cause of flooding.
The method with the highest economic rationality from the point of view of land owners such as heirs, etc., that is, “most effective use” in real estate appraisals, would be for the land owner to sell the land to a real estate developer, and the business concerned will sell it as lots for sale.
However, in order to suppress flood damage caused by recent typhoons and frequent guerrilla torrential rains, etc., I think maintaining a farm is the most economically rational from the perspective of society as a whole.
In the future, in order to reduce flood damage, from the viewpoint of flood control measures, not only are fields with water retention functions not subject to fixed asset tax, etc., but it is also necessary to maintain or increase them by spending subsidies commensurate with water retention capacity. Early countermeasures by the country etc. are desired before the further decline in the number of fields and farmlands.
Reprinted from Real Estate Management Journal Co., Ltd. “Weekly Real Estate Management” (with permission)
