The impact of spatial and temporal variation in water quality by multivariate statistical analysis in east-southern Caspian Sea

This paper presents the results of soil hydrological and erosional responses to land use changes and cover types in Golestan province. Thus, the aim of this research was to investigate the role land use change on water quality and the erosion of soil in seven stations (Arazkose (s1), Pos pashteh (s2), Tilabad (s3), Saosara (s4), Ghezaghli (s5), Lezore (s6), Ramian (s7). In this paper, principal component analysis and hierarchical cluster analysis were used to investigate the water quality of the Gorganrod River. Water parameters were including: TDS, EC, runoff and sediment. Water samples collected every month over a four-year period from 7 sampling stations, along a 50 km section of Caspian Sea that is under the influence of anthropogenic and natural changes were analyzed. The results show significant hydrogeomorphic responses among land uses/covers, indicating arable land and coniferous afforestation as the most serious in terms of runoff and soil erosion. PCA has allowed identification of a reduced number of mean 2 varifactors, pointing out 98%, in TDS and EC, 73%, in runoff and sediment. CA classified similar water quality stations and indicated Ghezaghli as the lowest quality rather than the rest of stations, Arazkoseh, Pas poshteh, Tilabad, Saosara, Lezoreh and Ramian, were identified as affected by land use changes. A Scree plot of stations in the first and second extracted components on PCA also gave us a classification of stations due to the similarity of changing sources. CA and PCA led to similar results, though Ghezaghli was identified as the lowest quality station in both methods. CA gave us an overview of the problem and helped us to classify and better explain the PCA results.

Keywords:

CA , Land Use Change , PCA , Soil Erosion , Water Quality