Environmental issue has been considered more significant in many aspects of engineering decision-making process particularly in river management. There is an increasing effort to conserve functioning of rivers for hum...Environmental issue has been considered more significant in many aspects of engineering decision-making process particularly in river management. There is an increasing effort to conserve functioning of rivers for human use as well as nature, therefore environmental flow assessment has been widely developed. This paper discusses on environmental flow assessment of the Sekampung River, particularly on its middle reach. A new analytical approach based on water-sediment equations was introduced in order to determine a minimum environmental flow at the certain cross section of a river. The result of the new method was then compared with a minimum environmental flow provided by using two hydrological based methods, namely, Tennant and Flow Duration Curve Analysis (FDCA) method. The result shows that the concerned discharge provided by the water-sediment method (3.5 m3/s) is the smallest compare with a minimum environmental flow that is provided by both Tennant (5.7 m3/s) and FDCA method (4.5 m3/s). It is promising that the water-sediment method can be used as a simple approach on preliminary state of environmental flow assessment. The method involves not only water discharge but also its related sediment flow of the river in order to mitigate further ecological and morphological risks.展开更多
The seabed scouring and silting are very important to the construction of port and waterway engineering. Seabed deposition and erosion change is complicated due to the influence of sediment supply, human activities an...The seabed scouring and silting are very important to the construction of port and waterway engineering. Seabed deposition and erosion change is complicated due to the influence of sediment supply, human activities and other factors. The Yangshan Deepwater Port is the new deep water harbor, which is an important part of the Shanghai International Shipping Service Center. Its construction has received much attention. At present, the water depth from the 1 st to the 3 rd harbor district is currently suitable under regular dredging and tidal current action. The fourth harbor district will be built in the world’s largest fully-automated deep water wharf. In the study, bathymetry change of the entire sea area of the Yangshan Deepwater Port and the 4 th harbor district(i.e.,Phase IV project) waters were analyzed quantitatively using multiyear bathymetric, hydrological and sediment data. The results show that from 1998 to 2010, seabed changes are characterized by large volumes of erosion and sedimentation, which the southern part was deposited and the northern part was eroded in the inner harbor waters, but the seabed of the Kezhushan inlet was eroded. Seabed changes of Phase IV project waters generally show a scour tendency in recent few years with the annual scour rate about 0.7 m. Among the many factors, the existence of Kezhushan inlet and its influence of the western water flow play an important positive role in water depth changes under the ebb tide action.展开更多
Based on the monitoring results of environmental quality in the sea area near the Aojiang estuary in Wenzou during 2010-2012,the present situation of environmental quality in the sea area was analyzed and evaluated. T...Based on the monitoring results of environmental quality in the sea area near the Aojiang estuary in Wenzou during 2010-2012,the present situation of environmental quality in the sea area was analyzed and evaluated. The results show that p H,DO,CODMn,petroleum,and heavy metals( Cu,Pb,Zn,Cd,Hg,As and Cr) in the sea area near the Aojiang estuary did not exceed the second-class standard of Seawater Quality Standard( GB 3097-1997),but both inorganic nitrogen and reactive phosphate in the sea area exceeded the second-class standard seriously,and the water quality of the sea area was in an eutrophic state; domestic sewage and fertilizer loss were the main sources of nitrogen and phosphorus. The standard index of most evaluation factors of sediment quality except for Zn was smaller than 1,meeting the demands of sediment quality for environmental protection.展开更多
文摘Environmental issue has been considered more significant in many aspects of engineering decision-making process particularly in river management. There is an increasing effort to conserve functioning of rivers for human use as well as nature, therefore environmental flow assessment has been widely developed. This paper discusses on environmental flow assessment of the Sekampung River, particularly on its middle reach. A new analytical approach based on water-sediment equations was introduced in order to determine a minimum environmental flow at the certain cross section of a river. The result of the new method was then compared with a minimum environmental flow provided by using two hydrological based methods, namely, Tennant and Flow Duration Curve Analysis (FDCA) method. The result shows that the concerned discharge provided by the water-sediment method (3.5 m3/s) is the smallest compare with a minimum environmental flow that is provided by both Tennant (5.7 m3/s) and FDCA method (4.5 m3/s). It is promising that the water-sediment method can be used as a simple approach on preliminary state of environmental flow assessment. The method involves not only water discharge but also its related sediment flow of the river in order to mitigate further ecological and morphological risks.
基金The Fund of Tianjin Research Institute of Water Transport Engineering of China under contract Nos TKS180101,TKS170202 and TKS150207the National Natural Science Foundation of China under contract Nos 51509120 and 51779112+1 种基金the Shanghai Science and Technology Committee under contract No.15DZ1202300the Tianjin Science and Technology Plan Innovation Platform and Talent Special Fund Project under contract No.16PTSYJC00190
文摘The seabed scouring and silting are very important to the construction of port and waterway engineering. Seabed deposition and erosion change is complicated due to the influence of sediment supply, human activities and other factors. The Yangshan Deepwater Port is the new deep water harbor, which is an important part of the Shanghai International Shipping Service Center. Its construction has received much attention. At present, the water depth from the 1 st to the 3 rd harbor district is currently suitable under regular dredging and tidal current action. The fourth harbor district will be built in the world’s largest fully-automated deep water wharf. In the study, bathymetry change of the entire sea area of the Yangshan Deepwater Port and the 4 th harbor district(i.e.,Phase IV project) waters were analyzed quantitatively using multiyear bathymetric, hydrological and sediment data. The results show that from 1998 to 2010, seabed changes are characterized by large volumes of erosion and sedimentation, which the southern part was deposited and the northern part was eroded in the inner harbor waters, but the seabed of the Kezhushan inlet was eroded. Seabed changes of Phase IV project waters generally show a scour tendency in recent few years with the annual scour rate about 0.7 m. Among the many factors, the existence of Kezhushan inlet and its influence of the western water flow play an important positive role in water depth changes under the ebb tide action.
文摘Based on the monitoring results of environmental quality in the sea area near the Aojiang estuary in Wenzou during 2010-2012,the present situation of environmental quality in the sea area was analyzed and evaluated. The results show that p H,DO,CODMn,petroleum,and heavy metals( Cu,Pb,Zn,Cd,Hg,As and Cr) in the sea area near the Aojiang estuary did not exceed the second-class standard of Seawater Quality Standard( GB 3097-1997),but both inorganic nitrogen and reactive phosphate in the sea area exceeded the second-class standard seriously,and the water quality of the sea area was in an eutrophic state; domestic sewage and fertilizer loss were the main sources of nitrogen and phosphorus. The standard index of most evaluation factors of sediment quality except for Zn was smaller than 1,meeting the demands of sediment quality for environmental protection.
