The environmental impact of coastal sand mining activities in Hai Phong city was assessed using ten proposed sustainable criteria for socio-economic development,and ecological and environmental protection.These ten cr...The environmental impact of coastal sand mining activities in Hai Phong city was assessed using ten proposed sustainable criteria for socio-economic development,and ecological and environmental protection.These ten criteria were developed by the analysis of the Dynamics-Pressure-State-Impact-Response(DPSIR)framework,including one driver and pressure criterion(D and P),seven status and impact criteria(S and I),and two response criteria(R).Each criterion is quantified according to five specific evaluation criteria corresponding to the evaluation score from 1 to 5.The results of the ten criterion application for environmental impact assessment of coastal mining Hai Phong by weighting show that the areas with economic activities,benthic biodiversity,and coastal ecosystems are most negatively impacted(score 4/5 and 3.5/5).Other subjects suffer low to moderate impacts(score 1/5 to 3/5).The environmental impact of sand mining(2015-2020)is generally moderate(score ranging from 2/5 to 3/5).The set of adjusted criteria can be applied to similar activities in coastal provinces and cities in Vietnam.展开更多
Coastal erosion has become a worldwide concern, typically in the densely populated Asian mega-river deltas. Severe coastal erosion in the southern Red River Delta(RRD) has been intensively studied. Coastal morphologic...Coastal erosion has become a worldwide concern, typically in the densely populated Asian mega-river deltas. Severe coastal erosion in the southern Red River Delta(RRD) has been intensively studied. Coastal morphological change in the northern RRD was examined in detail through DEM(Digital Elevation Model) analysis based on time series of bathymetrical maps(1965–2004) and Landsat images(1975–2015) in this study. The results show that the northern RRD is featured by rapid coastal accretion in the past few decades, although suspended sediment flux has dropped by roughly 60% after the completeness of Hoa Binh Dam(HBD) in 1988 and relative sea level rose at 1.9 mm yr^(-1). However, accretion at the outer part of subtidal shoals and platforms was observed to slow down quickly or even turned into erosion in the last two decades. The resuspended sediments from the erosion zone can be transported landward to replenish the inner coastal zone, keeping the latter accretion in the near future to compensate for the sediment discharge decrease from the river. However, this lag effect should be terminated soon if other adverse effects go worse, e.g., damming rivers, sea-level rising, strengthening storms, land reclamation and other poor-designed coastal engineering. Coastal planners and managers should pay full attention to these changes.展开更多
Both China and Vietnam confront the challenges of natural geohazards and environmental changes in their deltas and coastal zones due to rapid urbanization, economic development, and the impacts of global climate chang...Both China and Vietnam confront the challenges of natural geohazards and environmental changes in their deltas and coastal zones due to rapid urbanization, economic development, and the impacts of global climate change. China and Vietnam initiated a comparative study of the Holocene sedimentary evolution of the Yangtze River Delta(YRD) and Red River Delta(RRD) for the period 2015–2018 in order to improve the understanding of the two delta evolution histories in the Holocene. Previous investigative data of the two rivers, onshore delta plains, and offshore subaqueous deltas have been explored and reinterpreted. New data gleaned from boreholes, piston cores, shallow seismic and hydrodynamic sources have been collected from the offshore YRD and the East China Sea inner shelf, and surface sediments and short cores have been collected from the RRD near-shore areas. Six focal areas of the joint project have been defined for comparative studies of the two deltas, including morphological development, sequential stratigraphy, coastline shifting, sedimentary characteristics, sedimentary dynamics, and correlation with anthropogenic global climate change. The results of these study areas are presented herein. The joint project also includes cooperative capacity building; exchanges of young scientists have been organized during the project period, and hands-on training in laboratory geochemical analysis, numerical modeling, and seismic data processing and interpretation have been provided by China and its Vietnamese geoscientist partners. Joint field excursions were organized to the upstream of the Yangtze and Red Rivers in Yunan Province, China, all the way downstream along the Vietnamese portion of the Red River. These joint studies have, over the past three years, improved understanding of the evolutionary history of these two major rivers and their mechanisms of source to sink. Joint project results of these two major deltas are not limited to the geosciences; the cooperative mechanical and operational experiences have been helpful for future cooperation in the field of marine geoscience between China and Vietnam, as well for cooperative activities with other ASEAN member countries.展开更多
The fast growth of Hai Phong ports in the two last decades requires not only their upgrading facilities but also expanding port area and dredging their shipping channels(existing and new ones)that generate a huge amou...The fast growth of Hai Phong ports in the two last decades requires not only their upgrading facilities but also expanding port area and dredging their shipping channels(existing and new ones)that generate a huge amount of unused dredged materials.While all existing dumping sites in sea waters and on land get over capacity,looking for new dumping sites in sea waters is an urgent need.This study is to zone coastal waters of Hai Phong for suitable dumping sites meeting sustainable coastal management.Multi-criteria overlay analysis on GIS platform was employed with the criteria of natural conditions,environment and socio-economics for zoning coastal waters of Hai Phong.These criteria were detailed into eight subcriteria and then developed to eight GIS weighted thematic sub-layers of bottom depth,litho-hydrodynamics,ecosystems,distribution of benthos,distance to residential areas and tourist sites,distance to aquaculture area,distance to ecosystems and distance to conservation areas.Analysis results show the highly suitable zone for dredged material dumping in South,South West Hai Phong at depth below 15m to the deeper areas.Disposals of dredged materials in the zone would minimize impacts on the environment,ecology and socio-economics in surrounding waters and coastal areas.展开更多
基金support of the VAST project,code VAST05.06/22-23.
文摘The environmental impact of coastal sand mining activities in Hai Phong city was assessed using ten proposed sustainable criteria for socio-economic development,and ecological and environmental protection.These ten criteria were developed by the analysis of the Dynamics-Pressure-State-Impact-Response(DPSIR)framework,including one driver and pressure criterion(D and P),seven status and impact criteria(S and I),and two response criteria(R).Each criterion is quantified according to five specific evaluation criteria corresponding to the evaluation score from 1 to 5.The results of the ten criterion application for environmental impact assessment of coastal mining Hai Phong by weighting show that the areas with economic activities,benthic biodiversity,and coastal ecosystems are most negatively impacted(score 4/5 and 3.5/5).Other subjects suffer low to moderate impacts(score 1/5 to 3/5).The environmental impact of sand mining(2015-2020)is generally moderate(score ranging from 2/5 to 3/5).The set of adjusted criteria can be applied to similar activities in coastal provinces and cities in Vietnam.
基金funded by the National Natural Science Foundation of China(Nos.41776052,41476031)the Joint Research Project Between China and Vietnam(NDT.01.CHN/15)the China-ASEAN maritime cooperation fund‘Comparative Study of Holocene Sedimentary Evolution of the Yangtze River Delta and the Red River Delta’
文摘Coastal erosion has become a worldwide concern, typically in the densely populated Asian mega-river deltas. Severe coastal erosion in the southern Red River Delta(RRD) has been intensively studied. Coastal morphological change in the northern RRD was examined in detail through DEM(Digital Elevation Model) analysis based on time series of bathymetrical maps(1965–2004) and Landsat images(1975–2015) in this study. The results show that the northern RRD is featured by rapid coastal accretion in the past few decades, although suspended sediment flux has dropped by roughly 60% after the completeness of Hoa Binh Dam(HBD) in 1988 and relative sea level rose at 1.9 mm yr^(-1). However, accretion at the outer part of subtidal shoals and platforms was observed to slow down quickly or even turned into erosion in the last two decades. The resuspended sediments from the erosion zone can be transported landward to replenish the inner coastal zone, keeping the latter accretion in the near future to compensate for the sediment discharge decrease from the river. However, this lag effect should be terminated soon if other adverse effects go worse, e.g., damming rivers, sea-level rising, strengthening storms, land reclamation and other poor-designed coastal engineering. Coastal planners and managers should pay full attention to these changes.
文摘Both China and Vietnam confront the challenges of natural geohazards and environmental changes in their deltas and coastal zones due to rapid urbanization, economic development, and the impacts of global climate change. China and Vietnam initiated a comparative study of the Holocene sedimentary evolution of the Yangtze River Delta(YRD) and Red River Delta(RRD) for the period 2015–2018 in order to improve the understanding of the two delta evolution histories in the Holocene. Previous investigative data of the two rivers, onshore delta plains, and offshore subaqueous deltas have been explored and reinterpreted. New data gleaned from boreholes, piston cores, shallow seismic and hydrodynamic sources have been collected from the offshore YRD and the East China Sea inner shelf, and surface sediments and short cores have been collected from the RRD near-shore areas. Six focal areas of the joint project have been defined for comparative studies of the two deltas, including morphological development, sequential stratigraphy, coastline shifting, sedimentary characteristics, sedimentary dynamics, and correlation with anthropogenic global climate change. The results of these study areas are presented herein. The joint project also includes cooperative capacity building; exchanges of young scientists have been organized during the project period, and hands-on training in laboratory geochemical analysis, numerical modeling, and seismic data processing and interpretation have been provided by China and its Vietnamese geoscientist partners. Joint field excursions were organized to the upstream of the Yangtze and Red Rivers in Yunan Province, China, all the way downstream along the Vietnamese portion of the Red River. These joint studies have, over the past three years, improved understanding of the evolutionary history of these two major rivers and their mechanisms of source to sink. Joint project results of these two major deltas are not limited to the geosciences; the cooperative mechanical and operational experiences have been helpful for future cooperation in the field of marine geoscience between China and Vietnam, as well for cooperative activities with other ASEAN member countries.
基金The authors gratefully acknowledge the support of the project coded DT-MT.2015.721the VAST project"Study on scientific basics to develop indices for sustainable use assessment of tourist beaches in North Coastal Vietnam",coded KHCBBI-01/18-20the VAST Scientific Research Support coded NVCC 23.03/20-20.
文摘The fast growth of Hai Phong ports in the two last decades requires not only their upgrading facilities but also expanding port area and dredging their shipping channels(existing and new ones)that generate a huge amount of unused dredged materials.While all existing dumping sites in sea waters and on land get over capacity,looking for new dumping sites in sea waters is an urgent need.This study is to zone coastal waters of Hai Phong for suitable dumping sites meeting sustainable coastal management.Multi-criteria overlay analysis on GIS platform was employed with the criteria of natural conditions,environment and socio-economics for zoning coastal waters of Hai Phong.These criteria were detailed into eight subcriteria and then developed to eight GIS weighted thematic sub-layers of bottom depth,litho-hydrodynamics,ecosystems,distribution of benthos,distance to residential areas and tourist sites,distance to aquaculture area,distance to ecosystems and distance to conservation areas.Analysis results show the highly suitable zone for dredged material dumping in South,South West Hai Phong at depth below 15m to the deeper areas.Disposals of dredged materials in the zone would minimize impacts on the environment,ecology and socio-economics in surrounding waters and coastal areas.
