The Effect of Spatial Scale Changes on the Process of Strategic Environmental Assessment and Hydrologic Analysis Persian Gulf and Omman Sea Watershed

Today SEA is one of the most important tools on which environmental considerations can be institutionalized in the planning system. In this regard, it is important to select the effect of scale jumps on the process of SEA. Therefore, in this study, with using the favor of spatial scale 1:250000 and satellite imagery ASTER and SRTM in the first order Persian Gulf and Omman sea watershed an attempt has been made to test whether SEA outputs are aligned with macro policies and to increase the scale in the spatial dimension. In this regard, first by inputting raw data of digital elevation model in Arc SWAT extension in Arc map software and processing their related calculations HRUs and then, introduce the 11 year climatic data to the SWAT model and implement (RUN) SWAT model at different spatial scales. The results showed that re-sizing the digital elevation model had a significant effect in the first order Persian Gulf and Omman sea watershed.