Evaluation of a simplified method for estimating spatial patterns of residential water use based on thermal remote sensing, Khan-Younis Governorate, Gaza Strip

Background: Water consumption (WC) data is critical for managing water crises in water-scarce countries, especially in those countries that are lagging behind technical advancement for collecting accurate WC data at the household level. There is a lack of methods for estimating WC. 

Method: Here, we introduce a simplified method for estimating WC data based on regression analysis of satellite Land Surface Temperature (LST) data for the Khan-Younis Governorate, Gaza Strip, for the year 2017. We demonstrate the potential for using WC-LST models with and without low-resolution population data to estimate residential WC for two spatial resolutions: Landsat TIR moderate resolution (100 m), and MODIS TIR low resolution (1000 m). Residential WC data is measured based on readings from water meters of 28, 000 individual houses. 

Results: The method performs better without the low-spatial resolution population data. The use of similar spatial resolution data or higher to Landsat 8 TIR (100 m) is a prerequisite for robust WC estimation. Although the method can easily be modified and applied in areas where no estimated water consumption data is available, using the regression equation might result in a poor result due to the use of different water supply sources as demonstrated for the periphery of Khan Younis city.