The application of GIS to irrigation water resource management in England and Wales

This paper reviews the nature of agricultural spray irrigation in England a nd Wales, and the emerging role of Geographic Information Systems (GIS) as a modelling and decision-making tool to irrigation water resource managemen t. Agricultural demand for water accounts for only two per cent of the tota l water use in the UK, but forms a significant component of direct abstract ion in certain catchments in dry Summers and in dry years. The temporal and spatial variations in demand (as well as supply)cause acute problems for m anaging existing water supplies and planning future needs. Water resource m anagers need to base their catchment strategies on predicted irrigation dem ands and growth rates which take into account the local variations in clima te, soil type, land use and irrigation practice, A GIS approach is particul arly well suited to this. The availability of appropriate data sources, tog ether with some recent example applications, are reported.