Dear Osama,

Climate change scenarios can be seen as combinations of greenhouse gas concentration scenarios (RCP scenarios), global climate models (GCMs) and downscaling methods. Generally, four RCP scenarios are considered and can be combined with many different GCMs available. Downscaling techniques can be grouped into dynamical downscaling methods (mainly including regional climate models - RCMs) and statistical downscaling methods. The choice and appropriateness of a particular method depends on the geographical and climatological characteristics of the study area, the aim of the study and the availability of data to apply a specific method. See for instance the attached paper by Marie Ekström and co-authors with gives an overview of downscaling methods.

Best wishes,

Martijn

 Osama, Please have a look at these papers. More on my RG site. Best,

Article Human and climate impacts on Columbia River hydrology and salmoids

Article Distinguishing human and climate influences on hydrological ...

Conference Paper Separation of climate and anthropogenic influences on Columb...

Also, this paper..

Article Distinguishing Human and Climate Influences on the Columbia ...

I would like to recommend you the paper of my colleague J. Ribalaygua:

Ribalaygua, J., Torres, L., Pórtoles, J., Monjo, R., Gaitán, E., & Pino, M. R. (2013). Description and validation of a two-step analogue/regression downscaling method. Theoretical and Applied Climatology, 114(1-2), 253–269. http://doi.org/10.1007/s00704-013-0836-x

This paper was used by ourselves in some works as the enclosed:

the best way to analyzing climate change through  remote sensing.......software used ArcGIS, ENVI, Erdas imagine.