landscape pattern changes and water quality relationship in zayandehroud river basin

landscape characteristics and land use patterns of watershed demonstrate extension, distribution, density and abundance of human interference. these factors can affect water quality of adjacent aquatic systems within a watershed. land use changes have caused various environmental problems for zayandehroud river,turned it as a sink of pollutant. therefore this is investigated that how would landscape characteristics and land use patterns change water quality and affect ecosystem management. the main goal of this study was to examine how landscape patterns (including number of patches, edge density, percentage of landscape, total edge and largest patch index) influence water quality. indexes (including ec, hco3, no3, cl, k, ca, cod, na, do, p, ph, bod5 and tds) were measured in 10 stations along the zayandehroud river.this is one of the most important rivers of the central plateau of iran.in this study, four classes of land use including cropland, orchard, residential and industrial area were identified in a period of eleven years (1997–2008). the results indicated that water quality was significantly correlated with both proportions and configuration of residential areas. total edge of industrial area had negative effects on water quality, especially on tds and cod. results of this study can be used not only for resource managers in order to restore the aquatic ecosystems but also for policy makers in evaluating alternate land management decisions.