METHODOLOGY TO IDENTIFY THE LEADING FACTORS OF RIVERSí ELECTRICAL CONDUCTIVITY.
CASE STUDY: JIU CATCHMENT (ROMANIA)
Gabriela-Adina MOROȘANU, Liliana ZAHARIA, PH. BELLEUDY, Gabriela-Ioana TOROIMAC
ABSTRACT. - Methodology to Identify the Leading Factors of Riversí Electrical Conductivity. Case Study: Jiu Catchment, Romania. The riverís conductivity is the capacity of the water to transport electricity and depends on the physical and anthropogenic characteristics of the catchment. This paper aims to investigate the spatial variation of the riversí electrical conductivity in order to identify the role of its main predictors, by using multivariate analysis and GIS methods. The study area, Jiu River basin, is located in the SW of Romania. It covers 10,000 km2 and has a high diversity of geographical features, which could explain the variations in conductivity. The paper is based mainly on field measurements on electrical conductivity and turbidity, in 19 sites on Jiu River and some tributaries. The recorded conductivity values ranged from 61 μS/cm to 1201 μS/cm. This wide variation may be caused by several factors, such as turbidity, lithology, soils, as well as land use. The Principal Components Analysis (PCA) highlighted that the chief variables which determine the increase of river conductivity are the geological substrate and the soil textures across the catchments (particularly marls). The results also show a close relationship between the dominantly clayey textures and the high values of conductivity. Additionally, anthropogenic disturbances (reflected by the extent of the agricultural and urbanized areas) are also likely to play a role in the local increase of electrical conductivity.
Keywords: electrical conductivity, turbidity, Jiu Watershed, multivariate analysis, geographical factors.