An Acoustic Doppler Current Profiler （ADCP） observation site was set up in the Western South Yellow Sea from 2012 to 2013 to study the local suspended particle matters （SPM） distribution pattern. The SPM concentra...An Acoustic Doppler Current Profiler （ADCP） observation site was set up in the Western South Yellow Sea from 2012 to 2013 to study the local suspended particle matters （SPM） distribution pattern. The SPM concentration could be semi-quantitatively represented by backscatter intensity （Sv）, converted by the echo intensity （E/） of ADCP. Results show two types of SPM in the water column： the quasi-biological SPM and quasi-mineral SPM. The quasi-biological SPM mainly exists in summer half year and is con- centrated above the thermocline. It has periodically diurnal variations with high concentration at night and low concentration in the daytime. The quasi-mineral SPM is located in lower part of the water column, with similar relation to monthly tidal current variation all year round. However, the daily quasi-mineral SPM distribution patterns vary between summer and winter half year. The sunlight is thought to be the origin factor leading to the diurnally vertical motion of the biological features, which might cause the diurnal Sv variation. Unlike in winter half year when tidal current is relatively single driving force of the monthly SPM pattern, the high speed current near the thermocline is also responsible for the concentration of quasi-mineral SPM in summer half year. The sediment input difference between summer and winter half year contribute to the varied daily variation of quasi-mineral SPM with re-suspended SPM ir~ winter and sediments from Yellow Sea Mud Area （YSMA） in summer. The seasonal variations in hydrodynamics, water structure and heavy-wind incidents are the primary factors influencing the differential seasonal SPM distribution patterns.展开更多
Based on the land use change data obtained from the interpretation of remote sensing images in 1985, 1995, 2005 and 2008, the research applied principal component analysis, Markov chain and ESDA method, and took culti...Based on the land use change data obtained from the interpretation of remote sensing images in 1985, 1995, 2005 and 2008, the research applied principal component analysis, Markov chain and ESDA method, and took cultivated land patch as the basic unit of landscape. A comprehensive measure of the fragmentation of cultivated land was made in Jiangsu counties and its temporal and spatial evolution characteristics and driving process from the perspective of landscape ecology were discussed. The results are as follows:(1)The overall fragmentation of cultivated land in Jiangsu Province presents that the eastern coastal areas are low, the interior of the west is high, the fragmentation of northern and southern Jiangsu is high, while the fragmentation of mid-Jiangsu is low.(2)The degree of fragmentation of cultivated land in most area of southern Jiangsu and midJiangsu showed an upward trend, while the fragmentation of cultivated land in northern Jiangsu showed a downward trend from 1985 to 2008. The degree of agglomeration of cultivated land is weakened continuously, the area of high value agglomeration is decreasing and the trend of "polarization" is weakening.(3) Topographic condition is the decisive factor for the formation of the difference pattern. The change of rural residential land, cultivated land and the scale of urban land use plays a role on the cultivated land fragmentation index, among them, the change of rural residential land scale has the most significant effect on cultivated land fragmentation.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 41030856)National 973 Project of China (Grant No. 2005CB422304)+1 种基金the Project of Taishan Scholarsupport of the R/V Dongfanghong 2 and Shared Voyage of the National Nature Science Foundation of China
文摘An Acoustic Doppler Current Profiler （ADCP） observation site was set up in the Western South Yellow Sea from 2012 to 2013 to study the local suspended particle matters （SPM） distribution pattern. The SPM concentration could be semi-quantitatively represented by backscatter intensity （Sv）, converted by the echo intensity （E/） of ADCP. Results show two types of SPM in the water column： the quasi-biological SPM and quasi-mineral SPM. The quasi-biological SPM mainly exists in summer half year and is con- centrated above the thermocline. It has periodically diurnal variations with high concentration at night and low concentration in the daytime. The quasi-mineral SPM is located in lower part of the water column, with similar relation to monthly tidal current variation all year round. However, the daily quasi-mineral SPM distribution patterns vary between summer and winter half year. The sunlight is thought to be the origin factor leading to the diurnally vertical motion of the biological features, which might cause the diurnal Sv variation. Unlike in winter half year when tidal current is relatively single driving force of the monthly SPM pattern, the high speed current near the thermocline is also responsible for the concentration of quasi-mineral SPM in summer half year. The sediment input difference between summer and winter half year contribute to the varied daily variation of quasi-mineral SPM with re-suspended SPM ir~ winter and sediments from Yellow Sea Mud Area （YSMA） in summer. The seasonal variations in hydrodynamics, water structure and heavy-wind incidents are the primary factors influencing the differential seasonal SPM distribution patterns.
基金Supported by National Natural Science Foundation of China(41301651,41401629)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Based on the land use change data obtained from the interpretation of remote sensing images in 1985, 1995, 2005 and 2008, the research applied principal component analysis, Markov chain and ESDA method, and took cultivated land patch as the basic unit of landscape. A comprehensive measure of the fragmentation of cultivated land was made in Jiangsu counties and its temporal and spatial evolution characteristics and driving process from the perspective of landscape ecology were discussed. The results are as follows:(1)The overall fragmentation of cultivated land in Jiangsu Province presents that the eastern coastal areas are low, the interior of the west is high, the fragmentation of northern and southern Jiangsu is high, while the fragmentation of mid-Jiangsu is low.(2)The degree of fragmentation of cultivated land in most area of southern Jiangsu and midJiangsu showed an upward trend, while the fragmentation of cultivated land in northern Jiangsu showed a downward trend from 1985 to 2008. The degree of agglomeration of cultivated land is weakened continuously, the area of high value agglomeration is decreasing and the trend of "polarization" is weakening.(3) Topographic condition is the decisive factor for the formation of the difference pattern. The change of rural residential land, cultivated land and the scale of urban land use plays a role on the cultivated land fragmentation index, among them, the change of rural residential land scale has the most significant effect on cultivated land fragmentation.
