Identification of the critical areas of Riparian Zones in relation to the pattern of land use and inappropriately sited septic tanks in the Woori Yallock Catchment, Victoria
Agricultural activities, settlements and septic tanks on rural properties are major sources of pollution of aquatic environments. These point and non-point source pollutions have significant impacts on the water quality of rivers and streams. Riparian vegetation can play a significant role in protecting water quality by filtering runoff, trapping and removing nutrients, sediments, pesticides and other chemicals originating on land. Without riparian vegetation, water treatment plants become necessary, but they are expensive to operate. Therefore, the establishment and maintenance of riparian vegetation zones or buffers has been considered as an effective means of preventing pollutants from reaching rivers and streams and maintaining water quality. This paper presents a study on the use of GIS in the identification of the critical areas of riparian zones in the Worri Yallock Catchment, Victoria, which are susceptible to the threat of pollution from adjacent land uses and septic tanks. Updated maps of land use and surface hydrological features were derived from digital remote sensing images. The riparian buffers were created in a GIS, which were then combined with the land use data to analyse quantitatively the riparian vegetation cover in the catchment, target critical riparian areas and identify high-priority sites for riparian vegetation plantation or restoration.