Taking Economic Zone on the Western Coast of the Taiwan Straits as the study area,we use GIS,remote sensing,mathematical statistics and other methods,to analyze the forest pattern and its variation characteristics in ...Taking Economic Zone on the Western Coast of the Taiwan Straits as the study area,we use GIS,remote sensing,mathematical statistics and other methods,to analyze the forest pattern and its variation characteristics in Economic Zone on the Western Coast of the Taiwan Straits during the period 1992-2008;use canonical correspondence analysis(CCA)to examine the effects of environmental factors on changes in forest pattern.The results show that the forest resources are rich in Economic Zone on the Western Coast of the Taiwan Straits,accounting for 61.40% of the total area,but the geographical distribution is very uneven,with obvious regional and elevation gradient difference;since1992,the forest has been dwindling in Economic Zone on the Western Coast of the Taiwan Straits,from 89 300 km2 in 1992 to 88 300 km2 in 2008;in terms of changes in region and elevation gradient,there is obvious difference in the forest,and the central and western forest of Wuyi Mountain tends to decline obviously;the main environmental factors influencing changes in forest pattern in Economic Zone on the Western Coast of the Taiwan Straits include temperature,sunshine hours,GDP per capita and precipitation;evaporation,evaporation and population density have weak effects on changes in forest pattern.展开更多
Based on the new data of the Quaternary along the coast of Hainan Island, China, this paper puts forward that the Holocene in Hainan Island can be divided into four formations: Wanning formation (Q41), Sanya formation...Based on the new data of the Quaternary along the coast of Hainan Island, China, this paper puts forward that the Holocene in Hainan Island can be divided into four formations: Wanning formation (Q41), Sanya formation (Q42-1), Qiongshan formation (Q42-2) and Ledong formation (Q43). Spore-pollen analysis shows that there are 6 spore-pollen zones existed, reflecting two cycles of climatic fluctuation from warm-dry to hot-humid. The climax of hot-humid period occurred 6,000-5,000 years B.P.. Based on the 14C dating data of the 38 samples representing the positions of ancient sea level, a breakthrough curve representing the sea level change during the Holocone is obtained, in which , a sea level change caused by tectonic movement is subtracted. Two cycles of rise-drop of sea level with three periods of high sea level were found. The period with the highest sea level is some 6,000-5,000 years B.P.. According to the rise-drop rate of sea level, four periods of the sea level change can be distinguished in展开更多
The in-situ hydraulic fracturing stress measurements have been carried out around the coastal marginal land in Fu- jian Province. And the characteristics of magnitude, direction and distribution of tectonic stress hav...The in-situ hydraulic fracturing stress measurements have been carried out around the coastal marginal land in Fu- jian Province. And the characteristics of magnitude, direction and distribution of tectonic stress have been obtained. Based on the observed stress data, the characteristics and activities of fault zones are analyzed and studied in the paper according to the Coulomb friction criteria. 1 The maximum horizontal principal compressive stress is in the NW-WNW direction from the north to the south along the coastline verge, which is parallel to the strike of the NW-trending fault zone, consistent with the direction of principal compressive stress obtained from geological structure and across-fault deformation data, and different from that reflected by focal mechanism solution by about 20°. 2 The horizontal principal stress increases with depth, the relation among three stresses is SH>Sv>Sh or SH≈Sv>Sh, and the stress state is liable to normal fault and strike-slip fault activities. 3 According to Coulomb friction criteria and taking the friction strength μ as 0.6~1.0 for analysis, the stress state reaching or exceeding the threshold for normal-fault frictional sliding near the fault implies that the current tectonic activity in the measuring area is mainly normal faulting. 4 The force source of current tectonic stress field comes mainly from the westward and northwestward horizontal extrusions from the Pacific and Philippine Plates respectively to the Eurasian Plate.展开更多
The coupling numerical model between astronomical tide and tsunamis was built based on the data of the COMCOT model, which was verified by the Japan "3·11" tsunami. The tsunami source of the Manila seis...The coupling numerical model between astronomical tide and tsunamis was built based on the data of the COMCOT model, which was verified by the Japan "3·11" tsunami. The tsunami source of the Manila seismic tsunami was designed and computed to analyze the risk of tsunami which will happen in the Guangdong coast. According to the results, the maximum quantity of water increasing and the time of the tsunami arriving at the Guangdong seacoast were calculated. The coupling simulation between astronomical tide and tsunamis has significant meaning for evaluating the risk and early-warning of tsunamis in the Guangdong coastal area.展开更多
基金Supported by Special Financial Project of the Ministry of Environmental Protection(2110203)
文摘Taking Economic Zone on the Western Coast of the Taiwan Straits as the study area,we use GIS,remote sensing,mathematical statistics and other methods,to analyze the forest pattern and its variation characteristics in Economic Zone on the Western Coast of the Taiwan Straits during the period 1992-2008;use canonical correspondence analysis(CCA)to examine the effects of environmental factors on changes in forest pattern.The results show that the forest resources are rich in Economic Zone on the Western Coast of the Taiwan Straits,accounting for 61.40% of the total area,but the geographical distribution is very uneven,with obvious regional and elevation gradient difference;since1992,the forest has been dwindling in Economic Zone on the Western Coast of the Taiwan Straits,from 89 300 km2 in 1992 to 88 300 km2 in 2008;in terms of changes in region and elevation gradient,there is obvious difference in the forest,and the central and western forest of Wuyi Mountain tends to decline obviously;the main environmental factors influencing changes in forest pattern in Economic Zone on the Western Coast of the Taiwan Straits include temperature,sunshine hours,GDP per capita and precipitation;evaporation,evaporation and population density have weak effects on changes in forest pattern.
文摘Based on the new data of the Quaternary along the coast of Hainan Island, China, this paper puts forward that the Holocene in Hainan Island can be divided into four formations: Wanning formation (Q41), Sanya formation (Q42-1), Qiongshan formation (Q42-2) and Ledong formation (Q43). Spore-pollen analysis shows that there are 6 spore-pollen zones existed, reflecting two cycles of climatic fluctuation from warm-dry to hot-humid. The climax of hot-humid period occurred 6,000-5,000 years B.P.. Based on the 14C dating data of the 38 samples representing the positions of ancient sea level, a breakthrough curve representing the sea level change during the Holocone is obtained, in which , a sea level change caused by tectonic movement is subtracted. Two cycles of rise-drop of sea level with three periods of high sea level were found. The period with the highest sea level is some 6,000-5,000 years B.P.. According to the rise-drop rate of sea level, four periods of the sea level change can be distinguished in
基金National Development and Reform Commission [2004]1138.
文摘The in-situ hydraulic fracturing stress measurements have been carried out around the coastal marginal land in Fu- jian Province. And the characteristics of magnitude, direction and distribution of tectonic stress have been obtained. Based on the observed stress data, the characteristics and activities of fault zones are analyzed and studied in the paper according to the Coulomb friction criteria. 1 The maximum horizontal principal compressive stress is in the NW-WNW direction from the north to the south along the coastline verge, which is parallel to the strike of the NW-trending fault zone, consistent with the direction of principal compressive stress obtained from geological structure and across-fault deformation data, and different from that reflected by focal mechanism solution by about 20°. 2 The horizontal principal stress increases with depth, the relation among three stresses is SH>Sv>Sh or SH≈Sv>Sh, and the stress state is liable to normal fault and strike-slip fault activities. 3 According to Coulomb friction criteria and taking the friction strength μ as 0.6~1.0 for analysis, the stress state reaching or exceeding the threshold for normal-fault frictional sliding near the fault implies that the current tectonic activity in the measuring area is mainly normal faulting. 4 The force source of current tectonic stress field comes mainly from the westward and northwestward horizontal extrusions from the Pacific and Philippine Plates respectively to the Eurasian Plate.
基金sponsored by the Youth Fund Project of the National Natural Science Foundation of China(51509023)the Open-end Fund Project of State Key Laboratory of Hydraulic Engineering Simulation and Safety(HESS-1401)+3 种基金Major Open-end Fund Project of Key Laboratory of South China Sea Rights Protection Technology and Application,State Oceanic Administration(SCS1606)Open-end Fund of Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province(2017SS04)Project supported by South China Sea Branch,State Oceanic Administration for Director of Marine Science and Technology(1417)Key Founding of South China Sea Branch of State Oceanic Administration(180106)
文摘The coupling numerical model between astronomical tide and tsunamis was built based on the data of the COMCOT model, which was verified by the Japan "3·11" tsunami. The tsunami source of the Manila seismic tsunami was designed and computed to analyze the risk of tsunami which will happen in the Guangdong coast. According to the results, the maximum quantity of water increasing and the time of the tsunami arriving at the Guangdong seacoast were calculated. The coupling simulation between astronomical tide and tsunamis has significant meaning for evaluating the risk and early-warning of tsunamis in the Guangdong coastal area.
