多波長センサーによるアラル海流域における灌漑実態の広域モニタリング

Abstract

In the Aral Sea basin, due to severe drought and land salinization, land use annually changes due to lack of water resource and local adaptation against salinization. However, these changes have not been recorded in national statistics. Therefore in this research, actual irrigated area was attempted to detect by satellite remote sensing. Diurnal difference of surface temperature was utilized, because surface heat capacity and cooling effect of evapotranspiration are different on irrigated area comparing to surrounding arid non-irrigated zone. The diurnal difference of surface temperature was from MODIS sensor which has 1km and 12 hours resolution. And additionally, land surface model was utilized to remove climatic and geological changes in temperature. As a result, suggested ΔST_[diff] index could detect distribution of irrigated area in main irrigated region in Uzbekistan and ΔST_[diff] value was lower where irrigated area fraction is large. Moreover, monthly and annual change of ΔST_[diff] was smaller from June to August in dry year.