Using remote sensing and GIS technology for an improved decision support: a case study of residential water use in El Paso, Texas

Abstract

This paper presents a case study of using remote sensing and geographic information system technology for extracting green-surface areas of a residential neighborhood (933.20 acres) of El Paso, Texas. Four IKONOS images (September 2000) and a parcel layer were used to identify the green-surface areas which is an important variable in modelling the outdoor water use of individual households. The modelled outdoor water use together with indoor water use was compared with water meter reading and was used to analyse the behaviour of individual household-based water consumption. The modelling processes improve our understanding of water consumption and resource distributions so that a better decision in water management can be made. The results showed that pervious (green) and impervious surfaces constitute 26% and 74% of the total area of the 2422 parcel lots, and 21% and 79% of the entire study area, respectively. Average indoor water use of 2374 residential parcels is 31 m³ (or 11 ccf) per month, derived by averaging the water use of December, January and February. Estimation of outdoor water demand for the landscape was based on monthly potential evapotranspiration information and the delineated green-surface area of each parcel. Thus, the difference between the water meter reading and estimated (indoor and outdoor) water uses can be calculated. This study provides an alternative and quick approach to help water departments in efficiently monitoring the water use of each household.

Keywords:

• geospatial analysis
• green surface
• impervious surface
• water use
• remote sensing

Acknowledgements

This study was supported by El Paso Water Utilities (EPWU). Special thanks to Jose A. Granillo and G. Randy Keller for the revisions on the first draft of the paper. A portion of this work was also supported by NASA under cooperative agreement NCC5-209 (PACES) and the University of Texas at El Paso. Many thanks also go to the three reviewers for their constructive comments and suggestions for improving the paper.