عنوان مقاله [English]
Point and nonpoint sources of pollution both affect water quality (Wang and Choi, 2005). Among the factors of non-point source, land use and land cover are the most important resources, which numerous research studied relationships between land use and water quality in different watersheds (Jun, 2011; Seeboonruang, 2012; Jun, 2013). There is a significant correlation between land use and water quality (Su et al. 2012; Wan et al., 2014) and this relationship is influenced by types and their spatial patterns land use.
Landscape metrics have been used since 1980s to determine the degree of heterogeneity of spatial and landscape structure, including composition and configuration. Three features of the landscape are structure, composition and configuration based on landscape ecology (Amiri et al., 2016; Forman and Godron, 1986), which can be measured and analyzed based on the specific landscape metrics (Rutledge, 2003). Landscape structure has a great influence on the flow of nutrients at the catchment area (Amiri and Nakane 2009; Turner and Rabalais 2003). Due to the fact that non-point pollution has contributed to water pollution, the effect of non-point sources due to the change in landscape patterns is very important (Basnyat et al. 1999; Bhaduri, 2000). Moreover, landscape shows spatial heterogeneity of specific basin, and different patterns can be observed at various scales (Herold et al., 2005). A better understanding of the relationship between landscape metrics and water quality indicators can increase efforts in water management and research (Kearns et al., 2005).