Analysis of flood spreading systems and introducing research needs

Floodwater spreading over the alluvial cones in the basin outlets aiming the exploitation of floodwaters with sudden inevitable occurannce, establishment of suitable farming lands on alluvial cones, is the fastest, the most economic can the most scientific method for emploitation and storage of water produced by wadi floodwater and seasonal rivers and also entra flows of permanent rivers under management. Floodwater control, artificial recharge of aquifers and endeavour to optimize exploitation from natural resources are the most Important measures taken in floodwater spreading in arid and semiarid zones. Though using any kind of water with good quality is suitable for this floodwater due to amplitude and being free of charge and the need to decrease it';s risks and damages is inevitably used. Although regarding optimum use of water and soil, which is the important principle in flood extension, irrigation of pastures is performed in the largest area and the artificial recharge of aquifers is fulfilled in the smallest area. Nevertheless, the importance of recharging depleted aquifers of our country and the reclamation and improvement of the distorted pastures, running sand stablizition and finally the conservation of soil and decrease of the damages on one hand and the unexpensiveness of network estabilishment and ample economic yield on the other hand make the floodwater extension practical and reasonable in the largest possible area. Regarding the dispersion and expansion of the zones suitable for floodwater spreading systems establishment and the variety main factors affecting their design and implementation, the evaluation of the function of different components of floodwater spreading systems established in various districts of the country seems necessary. Thus, the study of the reasons for occurrence of problem regarding these systems with the definition of research projects implementation takes special place. To realize this important idea, analytic study of existing shortcomings in the function of component of floodwater spreading systems and classification and presentation of advantages and disadvantages of these systems will be a proper base ahead of researches to define and implement research plans in this field. Thus, in this paper while explaining and analysing the used guidelines and criteria in site selecting, designing implementing of the 36 floodwater spreading stations, the titles of related research plans have been presented regarding existing problems. Keywords: Flood, Floodwater Spreading, Designing, Site Selection