Based on tidal data statistical analysis for 20 years of Tanggu Marine Environmental Monitoring Station from 1991 to 2010, we concluded that an average of nearly 10 days of 100 cm above water increase took place at Ti...Based on tidal data statistical analysis for 20 years of Tanggu Marine Environmental Monitoring Station from 1991 to 2010, we concluded that an average of nearly 10 days of 100 cm above water increase took place at Tianjin coast every year. The maximum high tide and average tide of Tianjin coast occurred in summer and autumn, and the maximum water increase also occurred in summer and autumn. Days with water increase more than 100 cm mostly occurred in spring, autumn and winter. Then we summarized the causes of coastal storm surge disaster in Tianjin based on astronomical tide factors, meteorological factors, sea level rise, land subsidence, and geographic factors, et al. Finally, we proposed storm surge disaster prevention measures.展开更多
The existing models of population distribution often focus on the region with a single city or even multiple centers, and lack the detailed explorations of the common and special type of urbanization areas with two ce...The existing models of population distribution often focus on the region with a single city or even multiple centers, and lack the detailed explorations of the common and special type of urbanization areas with two centers. Taking Beijing-Tianjin region of China, which is a distinct dual-nuclei metropolitan area in the world, as an example and choosing Landsat-5 TM image in 2005, population, etc. as the data, this paper devotes to comprehending and illustrating a model of Cassini growth of population between the two metropolitan cities through the research of spatial population distribution pattern, aided with RS and GIS techniques. Main technical processes include Kriging interpolation of the population data and character simulation of the Cassini ovals. According to the calculation of a/b, a key characteristic index of Cassini growth model, the spatial structures of population distribution were given. When a/b〈 1, it is a curve with two separated loops with a population density more than 3000 persons/km^2. When a/b=1, it is a lemniscate curve with a population density about 3000 persons/km^2. When 1〈a/b〈 √2, it is a dog-bone shaped concave curve with a population density between 500-3000 persons/km^2. When a/b= √2, it is an oblate curve with a population density about 500 persons/km^2. When a/b〉 √2, there is an oval-shaped convex curve with a population density less than 500 persons/km^2. The results show that owing to the combined action and influence of the regional dual-nuclei, the population distribution of Beijing-Tianjin region is in accord with Cassini model significantly. Therefore, there is Cassini growth of population between the two metropolitan cities in Beijing-Tianjin region. In addition, the process of Cassini growth has extraordinarily instructive significance for judging the development stages of the dual-nuclei metropolitan areas.展开更多
Based on the data of releasing and enhancement of Tianjin Bohai Sea Fisheries Research Institute,this study has entirely summarized the experiences and achievements on releasing and enhancement works in Tianjin since ...Based on the data of releasing and enhancement of Tianjin Bohai Sea Fisheries Research Institute,this study has entirely summarized the experiences and achievements on releasing and enhancement works in Tianjin since 2006.Since 2006,Tianjin has launched the first multi-proliferation and release activity with"Fenneropenaeus chinensis"as the leader.So far,more than 22 varieties have been proliferated,among which crustaceans are dominant.There are significant ecological,economic and social benefits.Both national and international development trends of releasing and enhancement are summarized,and demands and objective of industrial development are proposed.展开更多
文摘Based on tidal data statistical analysis for 20 years of Tanggu Marine Environmental Monitoring Station from 1991 to 2010, we concluded that an average of nearly 10 days of 100 cm above water increase took place at Tianjin coast every year. The maximum high tide and average tide of Tianjin coast occurred in summer and autumn, and the maximum water increase also occurred in summer and autumn. Days with water increase more than 100 cm mostly occurred in spring, autumn and winter. Then we summarized the causes of coastal storm surge disaster in Tianjin based on astronomical tide factors, meteorological factors, sea level rise, land subsidence, and geographic factors, et al. Finally, we proposed storm surge disaster prevention measures.
基金Under the auspices of National High-Tech Research and Development Program of China(863 Program)(No. 2007AAl22235)National Natural Science Foundation ofChina(No.40471058)
文摘The existing models of population distribution often focus on the region with a single city or even multiple centers, and lack the detailed explorations of the common and special type of urbanization areas with two centers. Taking Beijing-Tianjin region of China, which is a distinct dual-nuclei metropolitan area in the world, as an example and choosing Landsat-5 TM image in 2005, population, etc. as the data, this paper devotes to comprehending and illustrating a model of Cassini growth of population between the two metropolitan cities through the research of spatial population distribution pattern, aided with RS and GIS techniques. Main technical processes include Kriging interpolation of the population data and character simulation of the Cassini ovals. According to the calculation of a/b, a key characteristic index of Cassini growth model, the spatial structures of population distribution were given. When a/b〈 1, it is a curve with two separated loops with a population density more than 3000 persons/km^2. When a/b=1, it is a lemniscate curve with a population density about 3000 persons/km^2. When 1〈a/b〈 √2, it is a dog-bone shaped concave curve with a population density between 500-3000 persons/km^2. When a/b= √2, it is an oblate curve with a population density about 500 persons/km^2. When a/b〉 √2, there is an oval-shaped convex curve with a population density less than 500 persons/km^2. The results show that owing to the combined action and influence of the regional dual-nuclei, the population distribution of Beijing-Tianjin region is in accord with Cassini model significantly. Therefore, there is Cassini growth of population between the two metropolitan cities in Beijing-Tianjin region. In addition, the process of Cassini growth has extraordinarily instructive significance for judging the development stages of the dual-nuclei metropolitan areas.
文摘Based on the data of releasing and enhancement of Tianjin Bohai Sea Fisheries Research Institute,this study has entirely summarized the experiences and achievements on releasing and enhancement works in Tianjin since 2006.Since 2006,Tianjin has launched the first multi-proliferation and release activity with"Fenneropenaeus chinensis"as the leader.So far,more than 22 varieties have been proliferated,among which crustaceans are dominant.There are significant ecological,economic and social benefits.Both national and international development trends of releasing and enhancement are summarized,and demands and objective of industrial development are proposed.
