IDENTIFY THE POTENTIAL SITES FOR RAINWATER HARVESTING. POTOHAR PLATEAU AS A CASE STUDY

Abstract

As all know that water is the essential component of life. The management of water resources in Potohar plateau is a complicated subject because to scant data, fast population expansion, verified geographic and climatic environment. As Pakistan considering to be among the water stress country by 2050. Groundwater is main sources of water for household, agriculture, and industrial uses, Pakistan mostly depends on the agriculture sector. As a result, the water level on the ground declining rapidly. The influence of changing climate on water supply can be mitigated via water collection. Rainwater harvesting systems (RWH) are the sole answer to a region's water constraint. Rainwater harvesting is a sustainable water treatment approach used all over the world to preserve available water. The selection of optimal rainwater collection locations is a key step in maximizing water supplies, soil quality, and aquifer protection in an area. The potential aim of this study is to identify the optimum suitable sites for RWH using modern techniques such as Multicriteria Analysis (MCA) integrated with Geographic Information System (GIS) and Remote Sensing (RS). Criteria is based on biophysical factor; the factor were identified on the bases of literature study. Seven factor is used in the overlay analysis to generate suitability map of RWH. In the analysis of thematic layer criteria weight were assign through Fuzzy AHP(FAHP). For assign weight local experts asked to evaluate the relative significance of specified criteria. Their consistency ratio of expert’s opinion was analyzed by using pairwise assessment method, the ultimate weight was assigned to each criterion using FAHP. Result indicates that some of the area is favorable for overall rainwater harvesting structure, and most of the land is suited for rainwater gathering ponds due to geographic pattern of study area. The optimally suitable and moderately suitable area cover about 67% of total area for pond RWH. As a result, the study location is ideal for the RWH system. For validation of result, application used is google earth pro to validate the suitability area. This is conformed from some already build up RWH structures exist on the proposed suitability area.