Urban Rainfall Harvesting to Alleviate Water Shortages and Combat Desertification in the Arid Land of Jordan

Abstract

Abstract: Water harvesting can alleviate the chronic water supply shortages in Jordan, increase cropping land area, improve the livelihood of population and eventually combat desertification. A systematic study was undertaken to evaluate the use of rooftop rainfall harvesting in urban areas, study the socioeconomic value, determine the optimum rainfall collection tank volume and the potential contribution of rainfall harvesting to the national domestic water supply budget. The potential water supply volume from rooftop rainfall harvesting can reach 14.7 million m 3 /year, comprising of about 6% of the domestic national water supply. Analysis of domestic water supply rate in relation to average rainfall depth and number of cisterns in each governorates indicated that the public water supply rate decreased in governorates with high rainfall depth and large number of cisterns. Cistern number among governorates increased with rainfall depth indicating a good adaptation behavior to water shortages. Optimum cistern volume charts were constructed for some governorates as a function of family consumption rate and house roof area. These charts can be used as tool to determine the optimum rainfall cistern volume as related to consumption rate and rooftop area. An immediate and nationwide awareness and legislative program is needed to spread rooftop rainfall harvesting among the whole population of Jordan and region with similar climates