A study on the relationship between urbanization and surface water quality based on GIS technique—a case study of coastal counties in Yantai

In this paper, the artificial land in the urbanization process was defined as the construction land.The construction land data of Yantai coastal counties was obtained from remote sensing TM imageries in 2004.The ratio of construction land and population density in the county level were extracted by buffer zones analysis with radius ranging from 100 m to 2 000 m.The superposition analysis for construction land ratio, population density, waterways rank and water quality was done through the ArcView spatial analysis function.Meanwhile, the spatial variation situation of water quality parameters of 28 water quality monitoring stations in Yantai coastal counties was also discussed with stepwise regression method.The results showed that the construction land ratio together with population density might explain over 85% water quality parameters model.The construction land ratio representing the urbanization level was better than population density in explaining spatial patterns of water quality parameters and the best models of most water quality parameters were found for buffer zones of 2000m radius,which indicated that the construction land ratio and the population density were the prime factors influencing water quality in the study area.It also suggested that the spatial analysis technology based on GIS, such as buffer and superposition analysis, provided a new way to study the relationship between region urbanization process and water environment quality.