Estimating water quality pollution impacts based on economic loss models in urbanization process in Xi'an, China

The study investigates water quality pollution impacts on urbanization by analyzing temporal and spatial characteristics of different water quality parameters, and simulating economic loss of water quality pollution in Xi'an, China from 1996 to 2003. Results show that organic pollutants were the greatest contributors of surface water quality pollution from 1996 to 2003. High values existed in petroleum concentration, chemical oxygen demand index (KMnO4), biochemical oxygen demand index, and phenol concentration, followed by nitrogen concentration (TN and NH3-N). From spatial analysis in different buffers from central urban area (inner buffers: 1-5km; central buffers: 5-10km; outer buffers: >10km), socioeconomic activities such as business activities, car transportation, industry factories, agriculture practices, and households were likely to lead to different behaviors of water quality parameters in nature. Results also reveal that both surface and ground water quality improved gradually after enforcement of control measures within the 7 years from 1996 to 2003. It shows the total economic loss, including cost of water use and supply, agriculture economic loss, ecosystem conservation costs, and economic loss of human health, reached $1.12 × 10 ⁹ from 1996 to 2003, which increased $1.79 × 10⁷ from $1.26 × 10⁸ in 1996 to $1.46 × 10⁸ in 2003. However, economic loss of water quality pollution increased while water quality pollution alleviated in the past years. This can be explained by more intensive social activities in broader regions, more populations were moved from rural area into urban area, and more costs were input in water quality pollution treatment.