Using Satellite Remote Sensing to Study the Effect of Sand Excavation on the Suspended Sediment in the Hong Kong-Zhuhai-Macau Bridge Region

Fenfen Liu,Tonghui Zhang,Shilin Tang,Haibin Ye

doi:10.3390/w13040435

Abstract

The Hong Kong-Zhuhai-Macau Bridge crosses the Pearl River Estuary and is the largest bridge and tunnel project in the world. During the construction period of this project, the excessive suspended sediment was found in the construction region. The suspended sediment generated by sand excavation in the upstream was assumed to have a significant impact on the suspended sediment in the tunnel region. In this study, we assessed the impact of upstream sand excavation on the suspended sediment in the Hong Kong-Zhuhai-Macau Bridge construction area using Landsat OLI, ETM+, and TM data. Regional suspended sediment algorithms were developed for Landsat using a symbolic regression method based on data from in situ measurements in the study area from 2003 to 2014. A band shift was conducted on the remote sensing reflectance data from Landsat ETM+ and OLI to produce a time series of the suspended sediment concentrations that was internally consistent with that of the Landsat TM data. The suspended sediment distribution was extracted and used to compare under two different conditions, with and without sand excavation. The correlations of the time series of the suspended sediment concentrations in different regions in the surrounding waters, including the correlations between the construction regions and the sand excavation regions, were calculated. Our results indicated that the sand excavation north of the Pearl River Estuary had a limited impact on the surface suspended sediment concentrations in the Hong Kong-Zhuhai-Macau Bridge tunnel area.

Highlights

The sediment in Lingding Yang is affected by a number of factors, including the topography, tides, runoff, and human activities [2]
We developed an explicit suspended sediment concentrations algorithm using symbolic regression
Based on years of field observations in the Pearl River Estuary, this study developed models to assess the suspended sediment concentrations in the Pearl River Estuary using Landsat satellites

Summary

Introduction

Sand Excavation in the Pearl River Estuary. The Pearl River is more than 2000 kilometers long, and it passes through several large cities before entering the South China Sea (Figure 1). Lingding Yang is one of the main estuaries of the Pearl River and is approximately 60 km wide, with Hong Kong to the east and Macau to the west. The sediment in Lingding Yang is affected by a number of factors, including the topography, tides, runoff, and human activities [2]. The average tidal range is from 0.86~1.63 m, of factors, including the topography, tides, runoff, and human activities [2]. The average tidal range is from 0.86~1.63 m, whichisiscategorized categorized asasa weak tide tide estuary, and theand

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Results

Discussion

Conclusion