Spatial assessment of sewage discharge with urbanization in 2004–2014, Beijing, China

Abstract

Beijing, China’s cultural political, and economic center, is facing critical water pollution-related challenges warranting global attention. This study used remote sensing and geographic information systems to analyze the impact of urbanization on wastewater discharge in Beijing. Two influencing factors—urban index and environment index—were created from remote sensing image classifications to better reflect the impacts from urbanization and green-cover changes on wastewater discharge. The impacts of urban land uses on the volume of wastewater discharge were examined in localized areas (i.e., the so-called unit watersheds delineated from topography and stream segments). Geostatistical results showed that urbanization was primarily responsible for spatial variations of wastewater discharge. While vegetation helped ameliorate the pollution, increased urban areas on the outskirts of the city resulted in accelerated wastewater discharge. Analytical findings of this study could provide spatially explicit information for policy-makers to initiate and adjust protocols and strategies for protecting water resources and controlling wastewater emission, thus improving quality of living environments in Beijing.

Keywords

• wastewater discharge; urban index; environment index; spatial analysis; Beijing