Estimating transmission losses in an arid region

Flow volumes in ephemeral streams in arid regions decrease significantly in magnitude downstream. These transmission losses are important not only in their obvious effect on flow reduction, but also as a source of groundwater recharge to underlying alluvial aquifers. A distributed model for estimation of transmission losses described herein represents an attempt to develop a procedure for practical applications and is shown to produce reasonable estimates. The model is simplified and requires a minimum of observed data for calibration. Based on available information obtained from Landsat Thematic Mapper False Colour Composites of bands 2, 3 and 4, published sources and regression analyses, the model can be used to estimate transmission losses from ungauged channels in arid regions. Transmission loss data are compared with some previously published data, and despite some scatter are generally consistent with them