Development of a GIS-based model to estimate landscape waterdemand at the urban/rural interface

In the arid west of the United States, there has been a redistribution of water from agriculture to municipal, industrial, recreational, and environmental uses due to population growth. A growing municipality in search for new water resources usually leads to a rural-to-urban conversion of water uses, affecting irrigated agriculture. Multispectral airborne digital images at one-metre resolution were collected over agricultural and urban landscaped areas in the City of Layton, Utah. Spectral signatures were extracted from the image representing the classes of interest. Water demand in the urban areas was calculated as the volume of water consumed by each house for irrigated landscape areas. Comparison between the estimated volume of water used for irrigation purposes and the actual water use obtained from the water billing data was studied. This study demonstrated the ability to use high-resolution airborne imagery in a GIS environment to estimate landscape water demand for individual houses or subdivisions. This allows the water supplier to identify and target particular end users with water conserving measures.