The structure of wind-sand flow under different total sand transport rates was measured with field vertical anemometer and sand trap on the crest of typical coastal transverse ridge in Changli Gold Coast of Hebei Prov...The structure of wind-sand flow under different total sand transport rates was measured with field vertical anemometer and sand trap on the crest of typical coastal transverse ridge in Changli Gold Coast of Hebei Province, which is one of the most typical coastal aeolian distribution regions in China and famous for the tall and typical coastal transverse ridges. The measurement results show that, on the conditions of approximate wind velocities and same surface materials and environments, some changes happen to the structure of wind-sand flow with the increase of total sand transport rate on the crest of coastal transverse ridge. First, the sand transport rates of layers at different heights in the wind-sand flow increase, with the maximum increase at the height layer of 4-8cm. Second, the ratios of sand trans-port rates of layers at different heights to total sand transport rate decrease at the low height layer (0-4cm), but increase at the high height layer (4-60cm). Third, the distribution of the sand transport rate in the wind-sand flow can be expressed by an exponential function at the height layer of 0-40cm, but it changes from power function model to ex-ponential function model in the whole height layer (0-60cm) and changes into polynomial function model at the height layer of 40-60cm with the increase of total sand transport rate. Those changes have a close relationship with the limit of sand grain size of wind flow transporting and composition of sand grain size in the wind-sand flow.展开更多
Movement of sediment load and its pattern of transportation along nearshore coastal water is a very important phenomenon to be assessed for different sector of coastal Engineering. To develop and understand the physic...Movement of sediment load and its pattern of transportation along nearshore coastal water is a very important phenomenon to be assessed for different sector of coastal Engineering. To develop and understand the physical processes responsible for shaping the ongoing evolution of the coast and to develop the management strategies to deal the impact of human activities on the coastal zone and as well as for adapting to the hazards associated with the people living on the coast, knowledge of the mechanism, processes and the pattern of sediment movement in the nearshore zone is of utmost importance. Nearshore zone is a very active area, where a series of dynamic processes occur in response to changing wave climates and sediment budgets. Nowadays mathematical modeling is an attractive alternative and becoming a very viable approach to study the sediment movement pattern with the advanced computational facilities and improved understanding on wave mechanics and sediment transport processes. It is very effective, reliable and also comfortable to study the pattern of sediment transportation including yield, distribution and management of sediment with the help of mathematical model. Validity of forecast in sediment transport depends on both mathematical modeling technique and boundary conditions.展开更多
基金Under the auspices of National Natural Science Foundation of China (No 40571019)
文摘The structure of wind-sand flow under different total sand transport rates was measured with field vertical anemometer and sand trap on the crest of typical coastal transverse ridge in Changli Gold Coast of Hebei Province, which is one of the most typical coastal aeolian distribution regions in China and famous for the tall and typical coastal transverse ridges. The measurement results show that, on the conditions of approximate wind velocities and same surface materials and environments, some changes happen to the structure of wind-sand flow with the increase of total sand transport rate on the crest of coastal transverse ridge. First, the sand transport rates of layers at different heights in the wind-sand flow increase, with the maximum increase at the height layer of 4-8cm. Second, the ratios of sand trans-port rates of layers at different heights to total sand transport rate decrease at the low height layer (0-4cm), but increase at the high height layer (4-60cm). Third, the distribution of the sand transport rate in the wind-sand flow can be expressed by an exponential function at the height layer of 0-40cm, but it changes from power function model to ex-ponential function model in the whole height layer (0-60cm) and changes into polynomial function model at the height layer of 40-60cm with the increase of total sand transport rate. Those changes have a close relationship with the limit of sand grain size of wind flow transporting and composition of sand grain size in the wind-sand flow.
文摘Movement of sediment load and its pattern of transportation along nearshore coastal water is a very important phenomenon to be assessed for different sector of coastal Engineering. To develop and understand the physical processes responsible for shaping the ongoing evolution of the coast and to develop the management strategies to deal the impact of human activities on the coastal zone and as well as for adapting to the hazards associated with the people living on the coast, knowledge of the mechanism, processes and the pattern of sediment movement in the nearshore zone is of utmost importance. Nearshore zone is a very active area, where a series of dynamic processes occur in response to changing wave climates and sediment budgets. Nowadays mathematical modeling is an attractive alternative and becoming a very viable approach to study the sediment movement pattern with the advanced computational facilities and improved understanding on wave mechanics and sediment transport processes. It is very effective, reliable and also comfortable to study the pattern of sediment transportation including yield, distribution and management of sediment with the help of mathematical model. Validity of forecast in sediment transport depends on both mathematical modeling technique and boundary conditions.
