Alireza Nasrabadi - The senior expert of watershed management, deputy director of general office of natural resources of southern Khorasan province, Birjand, Iran.
Gholamreza Hadarbadi - The chief of the research centre of agriculture and natural resources of southern khorasan province. Birjand, Iran
Morteza Dehghani - The senior expert of watershed management, general office of natural resources of southern Khorasan province, Birjand, Iran

Natural conditions dominant in catchments, socio- economic issues and technical and financial limitations compel us to do certain practicable activities in one or small part of the catchment. The most important concern of related engineers and executive experts is selection of suitable sub- area for implementing and starting of watershed management operations. Commonly prioritizing is based on the selected criteria or only on the basis of objective which is under consideration in watershed management for example flooding, soil erosion and so on. Fuzzy logic can cover a wide range of advantages, Disadvantages and different situations of decision making in prioritizing of watershed management operations. In this research, in order to investigation of taking advantage possibility of tested theory and skills in fuzzy logic for prioritizing watershed management operations aiming at flood control and sedimentation in Furg catchment of Darmian township ( Area: 11137 has ) was carried out. For this purpose, at first, different parameters and stages as fallows were calculated and carried out: 1. Physiographical factors including area, perimeter, River length, shape coefficients, branching rate, catchment slope, river density, average altitude and concentration time 2. Climatic factors including annual rainfall in 2, 5,10,25,,50 and 100 return periods and IDF in concentration time 3. Edaphic factors including soil texture, specific gravity, organic materials 4. Geomorphologic and geological factors including erosion form, geology formation in every work unit 5. Vegetation cover including determination of plant type, crown cover and bare soil percentage for every plant type 6. Hydrological factors including flooding discharge in 2, 5,10,25,,50 and 100 return periods which are calculated using fooler, kriger, push curve and rational methods and selection of proper model 7. Scoring MPSIAC factors 8. Factor analysis in order to decrease calculated factor without any mitigation of accuracy 9. Determination of fuzzy score of every mentioned factor 10. Prioritizing of watershed management operations based on flood and erosion parameters Results indicate in case of catchment flooding, sub-catchment of Dr`10 and in case of erosion, sub-catchments of Dr13, Dr14 and DR`5 have the first priority for implementation.

Analysis, Flooding, Fuzzy logic, Prioritizing of watershed management operations, GIS, MPISIAC