Hydrological impacts of land use/land cover change in a large river basin in central–northern Thailand

Abstract

AbstractThe purpose of this study is to determine the hydrological impacts of land use/land cover (LULC) change in the Yom watershed in central–northern Thailand over a 15‐year period using an integration of remote sensing, Geographic Information System, statistical methods, and hydrological modelling. The LULC changes showed an expansion of urban areas by 132% (from 210 km2 in 1990 to 488 km2 in 2006). The Yom River's daily discharge long‐term trend significantly increased at most of the measurement stations (p value < 0.05), and the rate of increase in discharge at areas downstream of the rapid urbanisation was significantly greater than that at areas upstream. There were no significant long‐term trends in precipitation characteristics in the basin, except for one station. The rate of change in discharge after changes in LULC showed a systematic increase over a range from 0.0039 to 0.0180 m3 s−1 day−1 over a 15‐year period, with the increase in urbanised area spanning a range from 81 to 149% in two flood‐prone provinces. A rainfall‐runoff model simulated a small increase (∼10%) in peak flows. The coupling of surface observations, remote sensing, and rainfall‐runoff modeling demonstrated the impacts of changes in LULC on peak river discharge, hence flooding behaviour, of a major river in central–northern Thailand. Copyright © 2010 Royal Meteorological Society