[1D15-20] Environmental Radioacitivty and Monitoring 3

[1D17] Investigation on distribution of radioactive substances in Fukushima

(13)Assessing the impacts of land cover and land-use change on soil erosion, hydrological process, and radioactive Cesium discharge in headwater catchments in the Fukushima prefecture-13

*Slim Mtibaa¹, Yuichi Onda¹, Sho Iwagami², Yoshifumi Wakiyama³ (1. Univ. of Tsukuba, 2. FFPRI, 3. Fukushima Univ.)

Keywords:Decontamination, Land-use change, Soil erosion, 137Cs discharge, Hydrological process

This study aimed at investigating the impacts of land cover and land-use change caused by decontamination works on soil erosion, hydrological processes, and radioactive Cesium (¹³⁷Cs) discharge. We monitored the sediment, water, and ¹³⁷Cs discharges, in tow USLE plots (before and after decontamination works) and a headwater catchment located in Yamamikiya district, Fukushima prefecture. We found that the decontamination works resulted in a radical decrease in the ¹³⁷Cs discharge, a change in the critical radio-cesium source areas, and an increase in sediment yield and surface runoff at plot and catchment scales. Our results provide clear evidence of the sensitivity of the hydrological process, soil erosion and ¹³⁷Cs discharge to the land cover and the land-use change.