No abstract

One of the critical pillars that sustain human civilization is meeting the water demand for different purposes like storage, electricity, flood control and others. In other hand, the mismanagement of water resources and unplanned urbanization denoted as the most obstacles for developing the arid and semi-arid regions. For this, it is important to know the appropriate places to construct such important projects and to evaluate those places if those places are actually suitable for constructing dams or not. In this paper, a hybrid Geographic information system (ArcGIS) decision-making technology powered by fuzzy logic is developed to assess seven small dams' sites in the Zawita district. Some standard criteria were used for evaluation like: Rainfall, Geological formations, Types of soil, Slope, Surface hydrological properties, and drainage density. The result all dams within the Zawita district are located in areas with suitable geological formations. It turns out that there are three finished dams that were built in relatively suitable places, they are: Botiya, Bari bhar, and Bhiri. Finally, As for the unfinished dams, one dam is considered an Unsuitable location according to all the criteria used, which is the Talwa dam and one dam within a relatively suitable location, which is the Eminki dam, while the Bisre dam was one of the appropriate dams that has not been built yet.

In any hydrologic study, the most important parameter is the runoff which is necessary for designing any hydraulic structure, and for determining the risk of flood. As there is a scare in the availability of runoff data in many sites, hydrologists have developed indirect methods to determine the runoff to accelerate the program of watershed management for conserving and developing water resources management. Many methods are used to estimate the runoff; Soil conservation curve number (SCS-CN) method is widely used and gives a reliable result compared with other methods. The present study aims to calculate the surface runoff depth depending on the SCS-CN method using a Geographic information system (GIS). For this Gali-Bandawa watershed in Duhok, north of Iraq has been selected, the geographical area of this watershed is about 92Km2 and the average annual rainfall is around 620mm, the weighted CN is 76. The results show that the depth of annual average runoff for the Gali-Bandawa watershed is 70mm, and the average volume of runoff from the same watershed is 6470360 m3. The amount of runoff represents 11.4% of the total annual rainfall. This approach could be applied in other Iraqi's watersheds for the planning of various conservation measures.