Industrial Wastewater Discharge Retrieval Based on Stable Nighttime Light Imagery in China from 1992 to 2010

Zhaofu Li,Hongyu Liu,Zhengqin Xiong,Chuan Luo,Hengpeng Li,Panpan Li

doi:10.3390/rs6087566

Abstract

Industrial wastewater (IW) discharge, which is a known point source of pollution, is a major water pollution source. Increasing IW discharge has imposed considerable pressure on regional or global water environments. It is important to estimate the IW distribution in grid units to improve basin-scale hydrological processes and water quality modeling. For the first time, we use the nighttime light imagery produced by the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP/OLS) to estimate the spatial and temporal variations in the IW distribution from 1992 to 2010 in China. The digital number values per unit area (DNP) of each stable light image were calculated using nighttime light imagery and were regressed against the IW per unit area (IWP) to estimate the total industrial wastewater (TIW) for each province. The results indicated strong positive correlations between the DNP and the IWP for each province during different years. The fitted linear regression models were used to estimate IW discharge in China with reliable accuracy. The IW estimation using the satellite data was consistent with the statistical results. The results also revealed that the IW discharge coverage expanded, whereas the IW discharge intensity decreased from 1992 to 2010 in China.

Highlights

Economic development and population growth have caused depletion of global water resources and serious problems for water environments [1,2,3]
The primary objective of this study was to evaluate whether Defense Meteorological Satellite Program (DMSP)/OLS nighttime light (NTL) data can be used as a potential remote sensing data source for estimating Industrial wastewater (IW), chemical oxygen demand (COD) and NH3N discharge spatial distributions in China
We found strong positive correlations between the digital number values per unit area (DNP) and the IW per unit area (IWP) for each province in different years

Summary

Introduction

Economic development and population growth have caused depletion of global water resources and serious problems for water environments [1,2,3]. A key challenge to sustaining future water environments is estimating both current and future water pollution. Population growth and increasing food requirements have caused increasingly serious domestic sewage and agricultural diffuse source pollution [4]. Rapid economic development, especially in industrial enterprises, creates more industrial wastewater [5]. With increasing point and non-point source pollution, the threat to the global water environment has become more severe [6]. Water environmental problems are challenging in China, because China has the largest population, a fast-growing economy, a rising water demand, relatively scarce water resources, a dated infrastructure and inadequate governance [7]

Objectives

Results

Conclusion