ECOSYSTEM SERVICE ASSESSMENT IN AGRICULTURAL WATERSHED BY USING TOPMODEL

Kosuke MUKAE, Koji MIWA, Hiromu OKAZAWA, Tomonori FUJIKAWA
2018 AGROFOR  
In Millennium Ecosystem Assessment established by the United Nations, theecosystem services (ES) provide benefits for human life as well as theenvironment. There is "regulating services" among all the supporting services. As aregulatory service, forests alleviate the flood risk after heavy rain by storingrainfall temporarily into forestlands and prevent the sudden increase in riverdischarge. The purpose of this research is to develop a hydrological modelling toassess this service in a watershed
more » ... where consists of not only forestland but alsograssland. TOPMODEL is applied for the quantification. This model was inventedto forecast river discharge in watersheds where the land use is uniform. However,the model has not been applied to a watershed where agricultural and forest areaare mixed in Japan. This research aimed to develop TOPMODEL to apply to suchcomplexed land use. Because the targeted watershed is consisted of two land-usetypes, TOPMODEL was applied in each grassland and forestland. It predicted theriver discharge by combining the predicted discharge from the different types ofland calculated by TOPMODEL. The result confirmed that by developing themodel, it was able to assess the water discharge from the both grassland andforestland in a watershed. The developed model also showed the betterreproducibility of river-discharge prediction than the conventional TOPMODEL.In addition, it clarified that the forestland stores more water than grassland into theground. Therefore, the effect of flood control which is the regulatory service of ESwas assessable through the developed model.
doi:10.7251/agreng1703027f fatcat:amslq3u445dm5kylu5ku26lbvi