Rainfall distribution in a catchment in Southwest Ireland:implications for catchment modeling

摘要

In rainfall-runoff models, it is of key importance that the rain-fall data used to drive the model adequately represent the dis-tribution of rainfall in the catchment being modelled (АNDRE-ASSIAN et al. 1999, CHAUBEY et a1. 1999, BEVEN 2002). The de-ployment of multiple rain gauges, even in a small catchments (4-5 ha), is no guarantee that the data will accurately represent the distribution of rainfall within the catchment (HORNBERGER et al. 1985, FAURE et al. 1995). In sparsely populated regions such as the west of Ireland there may be few or no rain gauges in a catchment and the modeller is forced to use rainfall data from outside the catchment of interest. In a previous study we used the General Watershed Loading Functions model (GWLF) to simulate daily discharge in 2 rivers using rainfall data from a single rain gauge located outside the catchments of both rivers. The aims of this study were to (1) ascertain the distribution of rainfall in a catchment in Southwestern Ireland by deploying a network of rain gauges, and (2) to test whether the quality of streamflow simulations could be improved by using data from the rain gauge network rather than those from the single rain gauge.