The Impacts on Water Quality Parameters of Different Land Uses On Catak Formation: Case of Galyan Dam, Trabzon

Abstract

Galyan-Atasu dam was built to supply with drinking, using, and industrial water needs of Trabzon and its surroundings. Surface water quality of the streams that feed the dam watershed are under the impact of land uses. This study was conducted to indicate the effect of different land uses to some water quality parameters of the river waters. In the study, a total of 6 sub-watersheds were selected in lower Galyan watershed. Land use (agricultural land, coniferous forests, broad-leaved forests and grassland) of research area was determined using Quick-Bird satellite imagery and forest management map. Over time period 2010 - 2011, water samples were obtained and analyzed for some water quality parameters in order to research their spatio-temporal variability in especial the relationship with land uses. Analysis of variance (ANOVA) showed significant spatial variability in pH, electrical conductivity (EC), total nitrogen (TN), Ca++ and K+ across sub-watersheds. Statistical analyses (correlation, regression) by analyzing the average values of the water quality parameters and different land uses patterns revealed that agricultural land was significantly correlated pH and TN, grassland was correlated pH, EC, TN and Ca++, coniferous forest was correlated pH, EC, Ca++, Mg++ and K+, broad-leaved forest was correlated pH, TN and K+. The research could provide important informations in sustainable land use for water resource conservation for the dam watershed.

Keywords: Galyan dam, Catak formation, sub-watersheds, land use, water quality parameters