Long-term analysis of effective heterogeneity of latent heat flux over diverse land use area

The evapotranspiration ET over a diverse land use area in northern Thailand was successfully estimated by a long-term 11-year eddy covariance measurement, while some measurement gaps due to instrumentation problems and administrative difficulties were unavoidable. The annual mean ET trend with a maximum of 150±10 mm in June and a minimum of 60±10 mm in January was estimated. The total annual mean ET was estimated to be 1300±140 mm. While the interannual variation of ET reflects the response of land surface to both meteorological events and land use/cover changes LUCC, over diverse land use area in northern Thailand, the effect of the rainfall variation to ET was greater than LUCC. Throughout an evaluating of the effective heterogeneity η with Bowen ratio, we suggest that such η information will be useful to understand the effect of land surface heterogeneity on latent and sensible heat fluxes.