ESTIMATING CROP DAMAGE IN RIVERS IN LOWLAND AREAS DUE TO INCREASED BACKWATER EFFECTS ARISING FROM CLIMATE CHANGE

Abstract

 This study aimed to estimate crop damage during floodwater inundation considering the effects of climate change on rivers in lowland areas. The Chitose River, a tributary of the Ishikari River, flows through low-lying land and is a topographically vulnerable area that is strongly influenced by backwater from the main river. In addition, Hokkaido produces several crops along the river basin, including wheat and soybeans, that account for a large share of the market, which in turn has a large impact on the national supply chain. In this study, we used rainfall information obtained from d4PDF downscaling data and Thiessen polygon data on farmlands to estimate crop damage in the Chitose River basin. Based on the amount of present and future crop damage estimated, the likelihood of damage exceeding 1.2 times that of the greatest damage ever recorded hitherto occurring in the future was shown.