Surface energy balance using satellite data for the water balance of a traditional irrigation - wetland system in SW Iran

A water balance of a large traditional irrigation area and a downstream adjoining wetland was determined using the surface energy balance approach (SEB), based on satellite data, to calculate the actual evaporation of both the irrigated area and the wetland at four different dates in a dry year and information of two additional images. The contribution of capillary flow by the shallow groundwater table was estimated by evaluating the actual evapotranspiration values of adjoining rangelands and non-inundated wetland areas. Those values were used to separate the total evapotranspiration into a soil moisture change component due to capillary rise, and into a component attributable to supply of river water. The only field data used for the estimated monthly water balance were air temperature, wind speed, and water inflow, since rainfall and outflow could be ignored in the year 2000. The results provided an insight for conditions of a drought year within the irrigated area, the distribution of water to irrigation and the wetland and showed the linkage between inundated wetland area and discharge