Use of the IHACRES rainfall-runoff model in arid and semi-arid regions

Abstract

Streamflow in arid and semi-arid regions tends to be dominated by rapid responses to intense rainfall events. Such events frequently have a high degree of spatial variability, coupled with poorly gauged rainfall data. This sets a fundamental limit on the capacity of any rainfall-runoff model to reproduce the observed flow. The IHACRES model is a parameterically efficient rainfall-runoff model that has been applied to a large number of catchments covering a diverse range of climatologies. While originally designed for more temperate climates, the model has been successfully applied to a number of ephemeral streams in Australia. The recently released Java-based version of IHACRES (Croke et al., 2005, 2006) includes a modified loss module, as well as a cross-correlation analysis tool, new fit indicators and visualization tools. Additional advances that will be included in future releases of the IHACRES model include: an alternative non-linear loss module which has a stronger physical basis, at the cost of a slightly more complicated calibration procedure; a baseflow filtering approach that uses the SRIV algorithm to estimate the parameter values; a modified routing module that includes the influence of groundwater losses (subsurface outflow and extraction of groundwater); and a technique to estimate the response curve directly from observed streamflow data. Successful management of water resources requires qualitative analysis of the effects of changes in climate and land-use practices on streamflow and water quality. Show more