The algorithms of chlorophyll-a concentration for CMODIS

The algorithms of extracting chlorophyll-a(Chl-a) concentration have been established for Chinese moderate resolution imaging spectrometer(CMODIS) mounted on Shenzhou-3 spaceship launched on 25 March 2002.The CMODIS is an ocean color sensor with 30 visible channels and 4 infrared channels,much different from other ocean color satellites and needs new algorithms to process data.Three models of Chl-a concentration were established based on Chl-a data retrieved from sea-viewing wide field-of-view sensor(SeaWiFS),with the average relative errors of 26.6%,24%.0% and 33.5%,respectively.This practical and economic approach can be used for developing the algorithms of Chinese ocean color and temperature sensor(COCTS) on the satellite Haiyang-1 to derive the Chl-a concentration concentration distribution.The applicability of the algorithms was analyzed using some in situ measurements.Suspended sediment is the main factor influencing the accuracy of the spectral ratio algorithms of Chl-a concentration.The algorithms are suitable to using in the regions where suspended sediment concentrations(SSC) are less than 5 g/m3 under the condition of relative error of Chl-a concentration retrieval within 35%.High concentration of suspended sediment leads to the overestimate remote sensing retrieval of concentration of Chl-a,while low-middle SSCs lead to the low Chl-a concentration values using the spectral ratio algorithms.Since the accuracy of Chl-a concentration by the spectral ratio algorithms is limited to waters of Case 2,it is necessary to develop semi-analytical models to improve the performance of satellite ocean color remote sensing in turbid coastal waters.     

Identification of Pb sources in Yellow Sea sediments using stable Pb isotope ratios

Rapid economic developments in East Asian countries have inevitably resulted in environmental degradation in the surrounding seas, and concern for both the environment and protection from pollutants is increasing. Identification of sources of contaminants is essential to environmental pollution management. In this study, the provenance of anthropogenic lead (Pb), a major pollutant of Yellow Sea sediments, was determined for river mouth sediments, including those of the Changjiang, Huanghe, Han, and Geum Rivers, and for age-determined shelf core sediments through the measurement of Pb isotope ratios in the HCl-leached fraction using multi-collector inductively coupled plasma-mass spectrometry (MC ICP/MS). Anthropogenic Pb has accumulated in shelf core sediments since 1910, and its isotope ratios were estimated as 0.863–0.866 and 2.119–2.125 for ²⁰⁷Pb/²⁰⁶Pb and ²⁰⁸Pb/²⁰⁶Pb, respectively, from the mixing relationships of the two endmembers. River mouth sediments exhibited enough distinction in anthropogenic Pb isotope ratios to be discriminated: 0.874 (2.144) in the Huanghe, 0.856 (2.129) in the Han, 0.857 (2.122) in the Geum, and 0.854 (2.101) in the Changjiang for ²⁰⁷Pb/²⁰⁶Pb (²⁰⁸Pb/²⁰⁶Pb), respectively. Although isotope ratios of geogenic Pb in sediments dating before 1910 showed narrow ranges (0.842–0.845 and 2.088–2.100 for ²⁰⁷Pb/²⁰⁶Pb and ²⁰⁸Pb/²⁰⁶Pb, respectively), distinct isotope ratios in each core permitted source identification of sediments in the Yellow Sea based on geographic locations and the geogenic Pb of each river. By comparing the isotope ratios of the estimated anthropogenic Pb to source-related materials, the provenances of anthropogenic Pb in Chinese river sediments were presumed to be Chinese coal or ore, which is also a major source of atmospheric particulate Pb. The anthropogenic Pb in the shelf core sediments in the northern Yellow Sea originated from northern Chinese cities such as Beijing and Tianjin through atmospheric pathways. Pb isotope ratios indicated that Pb in Korean river sediments was characteristic of local Korean ores.     

Distribution and number change of the Littorinidae (Gastropoda) on intertidal hard bed in the Jiulong River Estuary

There are 4 species of Littorinidae on the intertidal hard bed in the Jiulong River Estu-ary. They are Littorina scabra, L. brevicula, Nodilittorina pyramidalis pyramidalis and N.millegrana. Of these species, L. scabra is a dominant species. According to the results of in-vestigation, we find distribution patterns of the Littorinidae on intertidal hard bed in theestuary as follows: (1)There is no Littorinid species at Haicheng Station. (2)There is only Lit-     

Dinoflagellate cysts in recent marine sediment from Guangxi, China

Total of 33 species of dinoflagellate cysts were discovered from surface sediment in the searegion of Guangxi, among them 12 cyst types (Diplopsalopsis sp.1, D. sp. 2, D. sp. 3, Cochlodinium sp., Protoperidinium sp. 1, P. sp. 2, P. compressum , Scrippsiella sp. 1, S. sp. 2, Alexandrium sp. 1, A. sp. 2, A. sp. 3) were first reported from the South China Sea. And one cyst type (Cochlodinium sp.) was first reported in the world. Scrippsiella trochoidea is the dominant species in this area, accounting for 45% of all the cysts. There are 2 cysts of toxic dinoflagellate (Alexandrium tamarensis and Gymnodinium catenatum). But there is no relationship between cyst number and grain size distribution.     

热带气旋在东海的活动及其灾害分析

本文根据1949～1989年热带气旋历史资料,对影响东海的热带气旋进行了统计分析,结果表明,热带气旋在东海的活动相当频繁,特别是7、8、9三个月;热带气旋逐年出现个数有明显的年际波动和季节性变化;进入东海的热带气旋大致分为七类路径,不同路径的热带气旋对东海沿岸地区造成不同程度的危害,其灾情以具体实例作了阐述。     

南海东北部台风潮的数值后报及极值增水估计

本研究对近40年来影响南海东北部陆架海区的28次台风引起的风暴潮进行了数值后报,其中8个过程的沿岸后报增水值与实测值进行了比较,表明后报值与实测值符合良好,90%以上的最大增水值偏差在30厘米以下。为了得出本海区多年一遇的台风增水极值,在后报台风路径密集处选择了9个不同水深点,对每点取出各次台风下的最大增水值,然后用Weibull分布进行拟合,得出了各点的极值分布。     

台湾海峡中、北部上升流区浮游有孔虫的生态研究

分析１９８７—１９８８年在台湾海峡中、北部用浮游生物网采集的水层中的浮游有孔虫标本，研究调查海区浮游有孔虫的生态分布特征及其与海水温度和盐度的关系。结果表明：该海区浮游有孔虫计有１６种，以泡抱球虫Ｇｌｏｂｉｇｅｒｉｎａｂｕｌｌｏｉｄｅｓ为主要优势种类，其次是袋拟抱球虫Ｇｌｏｂｉｇｅｒｉｎｏｉｄｅｓｓａｃｃｕｌｉｆｅｒ和红拟抱球虫Ｇ．ｒｕｂｅｒ。在夏季的７月和８月（特别是７月），浮游有孔虫密集在福建中部沿岸的南日岛至闽江口外海海域一带沿岸水域，其中９０％以上的个体由泡抱球虫组成。此现象推测与夏季出现在福建沿岸的上升流活动有关。     

频率域电磁法中视电阻率全区定义

视电阻率定义在电法勘探中得到广泛的应用。目前在频率域电磁法中常常采用远区视电阻率定义。由于在频率域中收发距并非足够大,以致在低频段远区定义视电阻率往往不能反映地下电阻率值。我们定义全区电阻率及引入校正系数K,经二层三层模型及野外实测资料的计算,证明了方法的有效性。     

VR-GIS技术在高压输电线选线中的应用研究——以康定-崇州500kv送电线路为例

VR-GIS技术是一门新兴技术,已经在很多领域得到广泛应用。本文基于ERDAS、ArcGIS、MapGIS等遥感和GIS专业软件,将VR-GIS技术应用到高压输电线选线中,制作康定-崇州500kv送电线路(大杠～沙坪段)走廊带的三维景观飞行模拟系统,再现研究区真实地形、地貌,使工作人员沉浸于虚拟环境中,为其分析和处理问题提供方便,解决因自然环境恶劣造成的外业调查困难等问题。     

利用双向缓冲区算法综合海图岛屿

阐述了岛屿综合的内容和原则。介绍了双向缓冲区算法的概念并给出了双向缓冲区算法的定义,研究并证明了双向缓冲区算法的特性。分析了利用双向缓冲区算法综合海图岛屿的原理,并通过实验验证利用双向缓冲区算法综合海图岛屿具有较好的效果。