Developing Strategic Environmental Planning map Based on Land use Changes and Flood Zones Case study: Neka River

Providing the right and appropriate solution in the shortest possible time is a goal that a strategic planning follows among the risk factors. Land use changig is one of the invisible and hazardeous factors which icreases the flood zone and its return period. In this study, by using Landsat satellite images ETM 2000 and IRS-1D 2012, the percentage of land uses changing of Neka catchment area in Mazandaran province and level of flood occurance with return periods of (2, 5, 10, 25, 50, 100 and 200 years) in HEC-RAS and ENVI software environment were determined. Then the results were transferred to GIS environment and it was observed that in . the past decade, in addition to the change of land uses, the flood zone of the specified return period has also increased. The results showed that the use of agricultural lands has increased 2.27%, , unusable lands 7.31% and the urban lands 1.91 respectively. On the contrary, the forest and pasture lands has increase 10.22% and 1.27% respectively. The results of this study indicate that the HEC-RAS and HEC-GeoRAS using ARC GIS model can provide the appropriate numerical values and graphics for investigating the hydraulic characteristics of flow in rivers and for flood hazard mapping with more accuracy.