Mutawakil Obeidat Jordan University of Science and Arts Irbid-Jordan & Muheeb Awawdeh

1. GIS-Based Multi-Criteria Analysis For Mapping Potential Sites For Rainwater Harvesting In The Hamad Basin, Northeast Jordan Mutawakil Obeidat Jordan University of Science and Arts Irbid-Jordan & Muheeb Awawdeh Yarmouk University Irbid-Jordan

2. INTRODUCTION • Jordan is classified as one of the four water-poor countries worldwide • Responding to the challenges of water scarcity, the Jordanian government has adopted a multi-faceted approach designed to both reduce demand as well as increase supply by utilizing new water resources • With a considerable portion of the population living in the arid to semi-arid conditions of the country, it is necessary to look for different ways of increasing water resources such as water harvesting.

3. WATER HARVESTING • a method of water collection • applied in arid and semi-arid regions, where rainfall is either not sufficient to sustain a good crop and pasture growth or where, due to the erratic nature of precipitation, the risk of crop failure is very high • Water harvesting can be accomplished through in situ harvesting, soil conservation methods, and increasing infiltration for recharge of groundwater

4. Rainwater harvesting is a technology used for collecting and storing rainwater from rooftops, land surfaces, road surfaces or rock catchments using simple techniques such as pots, tanks and cistern as well as more complex techniques • Rainwater harvesting has recently been promoted to solve water problem for agricultural and domestic uses

5. OBJECTIVES • Evaluating rainwater harvesting potential by dams in the Hamad Basin • Developing a GIS-based model for rainwater harvesting in the study area.

6. STUDY AREA

8. RESEARCH METHOD • A GIS application was used to model the best sites for rainwater harvesting in the Hamad basin • A multi-criteria evaluation (MCE) technique is adopted in this study • MCE techniques are primarily concerned with how to combine the information from several criteria to form a single index of evaluation

9. In this technique, ‘weight’ is assigned to the data layers to reflect their relative importance. The Analytical Hierarchy Principle (AHP) method was used • Ratings are assigned to reflect the importance of a class within a category • National and International guidelines were followed

10. MATERIALS AND METHODS • annual rainfall (mm/year) • flow accumulation (unitless) • slope (%) • distance to wadi (m) • land use • soil texture (clay content %) • distance to settlement (m) • distance to roads (m) • distance to faults (m) • Curvature (unitless)

11. DATA SOURCE AND PREPARATION

16. RESULTS AND DISCUSSION 1-Faults

17. 2- Drainage system and distance to wadi

18. 3- Slope

19. 4-Flow accumulation-an index which estimates the surface runoff for each cell in the terrain-the total area of the grid cells which flow through that cell per unit width of contour

20. 5- Clay content: 19 soil units

21. 6- Distance to settlements

22. 7- Distance to roads

23. 8- Land use

24. 9- Rainfall

25. MODEL BUILDING • Using the overlay functionality in GIS the WHI model was determined by integrating all the previously discussed parameters Water harvesting Index (WHI)=(((Rw*Rr)+(FAW*FAR)+(Sw*Sr)+(LUw *LUr)+(STw *STr)+(DRw *DRr)+(DWw*DWr)+(DUw*DUr)) *(Fw *Fr) )*(CW*CR) Where: R: rainfall, FA: flow accumulation, S: slope, LU: land use, ST: soil texture, DR: distance to roads, DW: distance to wadi, DU: distance to urban, F: faults, C: curvature, w: weight, r: rating.

26. Curvature:the second derivative of the surface or the slope of the slope

29. CONCLUSIONS • GIS offers a powerful tool for mapping potential sites for rainfall harvesting • The areas covered by the very highly and highly suitable classes for rainfall harvesting are approximately 1665 km2 which needs further investigation • The most affecting factors on mapping the potential sites: rainfall, land use, soil, flow accumulation and slope respectively