Methodological Concern of Scale in Environmental Studies

Recently, the role of scale as one major restriction on nature recognition is hinted by many references. Accordingly, many experts attempt to explain it methodologically. On one hand, existing complex and complicated biological entities along with ambiguous methods and concepts of mechanical sciences measuring have caused the scale to remain as a crucial issue in ecology and environmental studies. On the other hand, emerging new technologies such as GIS and RS which access huge amount of data on the basis of scale, make fundamentally this issue as a significant subject of nature recognition, This methodological research is trying to explain the scale concept. Therefore, slope map as a principal element in environmental models, was chosen to assess the changes of outputs in terms of scale variety within Makhdum and Ahmadi Models, representative of environmental and watershed management models in Iran, respectively. For that reason, slope maps with two scales (25000 and 50000) and three pixel sizes (10, 20 and 50) were applied meanwhile, it is tried to obviate the misunderstanding which the scale was ignored by modeling process. So, four matrices were included and their changes were investigated by computation of covariance diagonal vector in each matrix. According to observational shifts that affected by scale and non scale factors while consideration of GIS and RS development, we concluded that the attitude of environmental models must be explained regarding scale concept. Also, the importance of new concepts related to scale (such as pixel size) and concerning the designing and planning phases have been emphasized.