Abstract
In this research, to review the role of geomorphological phenomena has been discussed in the change of chemical quality of water in the part of geography the north east of the country. Geomorphological phenomenon discussed in this research is marly hills that is result of volcanic-sedimentary activities of geological tertiary and is discussed the role of chemical effects this hills in mudding water one of the rivers current in its area (Kalateh-Sadat river in west Sabzevar) to irrigate agricultural lands around this river, that slang term to it "water-coloring" they say. In this study, methods of field observation, interview with local farmers, sampling and analysis of water and physicochemical experiments have been used. The results of tests and comparative the chemical quality of clear water and muddy water showed that the rate of deposition percent (turbidity), total hardness (concentration of calcium and magnesium) and water salinity (Electrical Conductivity) is higher in muddy water; but statistical analysis and diagramming Schuler & Wilcox and classification of SSP and SAR determined that this increase is not as critical and dangerous and the quality of potable and agricultural water of Kalateh Sadat river and even its total hardness is in favorable condition and well. In other words, marly hills and water mudding does not cause of significant changes in water chemical quality of river; Therefore, can be used of muddy water for irrigating agricultural land.