Surface Water Quality Assessment Using Linear Modeling Approach to Long-Term Environmental Changes (Case Study of Amirkabir-Karaj Dam Basin)

Subject Areas :

Sara Ranjbari ¹ , Jamal Ghodusi ² , Reza Arjmandi ³ , Amirhessam Hassani ⁴

1 - Ph.D. of Environmental Management, Department of Environmental Science, Faculty of Natural resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran.
2 - Associate Professor, Faculty Member of Soil and Watershed Management Institute. Tehran, Iran.
3 - Associate Professor, Department of Environmental Science, Faculty of Natural resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran
4 - Professor, Department of Environmental Science, Faculty of Natural resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran

Received: 2021-11-28 Accepted : 2021-11-28 Published : 2020-12-21

Keywords: Correlation analysis, Main Components, Time Trend, Watershed Activities, Amir Kabir Dam,

Abstract :

The special importance of the Karaj River and Dam in the establishment of sustainable security of water supply in Tehran and maintaining the ecological stability of the aquatic environment and human activities related to water play a prominent and vital role. The aim of this study was to identify sources of pollutants. Quality of surface water resources for 8 water quality parameters (sulfate, chlorine, calcium, magnesium, sodium, potassium, total solute, electrical conductivity and sodium uptake ratio) in 10 Karaj-Amir dam dams It was great. In this study, the effect of changes in hydrological parameters on pollutant sources as well as the spatial origin of these pollutants and the appropriateness of watershed management measures during the 40-year period from 1347 to 1398 were investigated using Convik correlation analysis and principal component analysis. The results showed that the application of factor analysis in evaluating surface water quality parameters is one of the important cases for source and elimination of information noise. Focal variables 1 and 2 with correlation coefficients of 0.98 and 0.81 have potential ability especially for changes in environmental variables such as rainfall (H) and The volume of annual sediments (W) has a direct effect on the three elements of water quality, namely calcium, total salts and total hydrogen ratio, respectively, and they establish a direct relationship. The results showed that the share of incoming pollution load from the tributaries of the Karaj River due to the uses located in them in the pollution of the dam reservoir is more than the main tributary of the river and its uses. In particular, the sub-basins of Velayatrud, Shahrestanak and Sira have a total of more than one third of the share of pollution entering the reservoir.