西藏年楚河满拉水库上游冰川变化及其影响

西藏年楚河流域满拉水库上游的冰川融水对"一江两河"地区的农业和水利发电十分重要,而气温升高导致青藏高原冰川普遍退缩.利用1980年地形图、1990年Landsat TM、2000年LandsatETM+和2005年CBERS遥感影像估算了满拉水库上游冰川面积的变化,并评价了其可能影响.结果表明,1980-2005年无表碛物覆盖的冰川面积减少了7.34%(13.42km2).冰川退缩近期将对农业灌溉、水利发电产生积极影响.然而,由于大量的小冰川(2km2)将会在未来快速退缩和消失,导致水资源短缺.同时,冰川补给湖泊呈快速扩张趋势,冰湖溃决洪水发生的可能性将大大增加.     

利用TM遥感影像和DEM估算山区地表反照率

利用Landsat TM遥感影像可见光-近红外波段的数据和DEM,计算了复杂地形条件下的反射率,再将窄波段的光谱反射率组合得到地表反照率.在计算反射率时解决了两方面的问题:计算太阳入射光谱辐射时考虑了微观地形因素的局地海拔、地形坡度、坡向、地形遮蔽等参数对较高分辨率影像的影响;考虑了大气对遥感图像的影响.在全面地考虑了大气和地形对影像影响的基础上,发展了一个适用于利用DEM和较高分辨率的卫星影像计算复杂地形条件下的地表反射率和反照率的模型.以黑河上游山区为例,利用TM图像和DEM计算了复杂地形条件下的地表反照率,对结果进行验证表明模型合理可行.     

环境与灾害监测预报小卫星CCD数据质量评价

中国环境与灾害监测预报小卫星星座双星4部CCD传感器具备大范围、全天时环境与灾害监测等方面的能力,在空间覆盖与重复观测频率方面有很大的优势。结合美国陆地卫星TM数据,从几何精度、辐射质量2个方面定量分析了该卫星CCD传感器的数据质量。结果表明：①环境减灾卫星CCD数据无波段错位现象,有极小的畸变与扭曲（0.05%）,然...     

西藏羊卓雍错湖面遥感监测模型及近期变化

羊卓雍错作为西藏高原三大圣湖之一和藏南重要的高原特色风景旅游景区, 其水域变化受到当地老百姓和各级政府部门的关注. 应用高分辨率陆地资源卫星等遥感数据可以方便、 准确地获取湖泊面积、 周长等信息, 但是由于Landsat 等高分辨率陆地资源卫星影像受到卫星重复周期和卫星过顶时多云天气的影响, 无法实现湖泊面积变化的常规业务化连续监测. 为此, 以Landsat 等高分辨率陆地资源卫星为主要遥感信息源, 结合羊卓雍错水位观测资料, 建立了羊卓雍错湖泊面积变化与水位波动之间的相关模型. 在此基础上, 利用该湖泊面积遥感监测模型, 结合近期水位观测资料分析了羊卓雍错湖面面积变化特征与趋势.     

闽江口水体变化的遥感动态监测

基于1986年和1994年的Landsat TM、2010年的SPOT5 3个时相的卫星影像,探讨福建省闽江口1986～2010年的水体变化规律.水体变化信息主要通过变化检测和信息提取等一系列遥感技术来获取.研究结果表明闽江口在1986～2010年,水库、湖泊和坑塘面积不断增加,这主要是由于城市用地扩展和养殖业的发展,从侧面反映了福州在1986～2010年,城市化进程和经济发展步伐有较大提高.     

利用遥感技术监测海水侵人沿海平原区并探测岩溶地区海岸线淡水溢出带-以希腊为例

该研究目的在于介绍所监测地区内遥感技术的应用。简要地描述以往遥感技术的使用,从地质学的角度为地质科学研究环境问题提供多时相和多光谱的影像帮助。同时侧重于以下两个重点：1．通过研究多时相卫星影像显示的地表植被特征差异（耐盐植被或盐生植被指标）,在沿海沉积平原区监测和划分由于过度开采水导致的海水入侵区域;2．通过使用卫星热红外影像,探测沿海岸线岩溶侵蚀岩地区的水流排泄区域。本文以沿海地区的海水入侵为研究重点。该地区的海水入侵演化为一个水文地质问题,并由此引发了一系列其它问题,其中一个水文地质问题是海水与沿海地区大量未使用的地下淡水之间的交换。在我们的实验室,借助LANDSAT-5／TM卫星影像（30米分辨率）已经努力对这些沿海区域进行监测和划定工作。对上述影像使用数字处理技术,划定Pieria县（马其顿省,希腊）受盐度影响的区域。另外,通过使用TM数据第6波段（热红外波段）找出希腊中部Itea海湾区域内的淡水泉。以上研究结果能够帮助水文地质专家找出受海水入侵和沿海区地下水排泄的区域。     

SPOT卫星数据图像处理方法及应用

使用ENVI图像处理软件进行SPOT卫星数据与TM数据进行复合制作卫星影像图技术研究，经反复试验，成功地研制成了既有明显色彩差异，又具有较高分辨率的假彩色遥感图像，为卫星遥感影像图开发利用提供方法技术。文章主有关的图像处理方法及其应用作简单介绍，仅供同行参考。     

利用卫星影像和航空影像更新基础地理信息方法研究

基础地理信息的更新,是保证地理信息系统现势性的充要条件.卫星遥感影像数据具有周期短、信息丰富、现势性强等特征.利用卫星影像数据来更新基础地理信息数据是一种行之有效的方法.如何利用遥感数据融合技术,将多传感器获取的各种影像数据中所含的信息优势有机地结合起来,更是成为目前研究的热点.利用航空影像和Landsat多光谱波段影像进行数据融合,能够有效地提高影像空间分辨率,以获取更高质量的信息.     

遥感蚀变异常信息提取在找矿方面的应用——以新疆富蕴地区为例

<正>利用Landsat5卫星的TM数据,结合相关地质资料,以富蕴县矿区为研究对象,通过对岩石矿物的波谱特征分析,以矿化蚀变的信息为目标,运用水体指数,城镇指数去除干扰因素,掩膜影像,波段比值、主成分分析(PCA)密度分割等方法,提取铁染异常,羟基异常等蚀变信息,最后结合圈出的异常区与已知矿点做比较,从而论证该技术在找矿方面的可行度。     

基于神经网络的沉陷区水深遥感研究

为获取煤矿积水沉陷区遥感影像数据与沉陷区水深的定量关系,建立了BP神经网络水深反演模型,并对淮南潘一矿积水沉陷区水深进行了反演。首先对Landsat卫星影像数据(TM影像)进行几何校正、大气校正和沉陷区范围提取等,然后输出像元反射率值,并与水深实测控制点坐标匹配,使水深值与反射率值对应。实验结果表明:以水深值2 m为阈值,水深值小于2 m的区域,模型反演水深值与实测水深值的平均绝对误差为0.166 3 m,平均相对误差为13.29%;水深值为2~6 m的区域,模型反演水深值与实测水深值平均绝对误差为0.578 6 m,平均相对误差为15.20%。      

Detection of algal bloom and factors influencing its formation in Taihu Lake from 2000 to 2011 by MODIS

Time-series MODIS data were used to extract and characterize algal blooms from the Taihu Lake study area. Water quality data including total nitrogen, total phosphorus, and dissolved oxygen; local meteorology data; and global climate trends were examined to reveal the factors influencing the formation of the algal blooms. Results for the 2000–2011 study period show that the annual algal bloom typically begins between March and May in Taihu Lake. All large-scale blooms originate from northern Taihu Lake (Meiliang Bay and Zhushan Bay). Some small-scale blooms originate from southwestern Taihu Lake, but the duration of these blooms is very brief because of episodes of turbulent mixing due to high wind speed. Nutrient supply is the main factor influencing algal mass propagation during bloom periods, and temperature changes may trigger algal recovery. The algal bloom area significantly decreased when wind speed is greater than 4 m/s, causing turbulence and changes in algal buoyancy. A strong East Asian summer monsoon transporting warm air to the lake is shown to extend the duration of algal blooms in Taihu Lake, as occurred in 2007.     

“我国近海有害赤潮发生的生态学、海洋学机制及预测防治”研究进展

介绍国家重点基础研究发展计划项目（“973”项目）“我国近海有害赤潮发生的生态学、海洋学机制及预测防治”的研究背景和主要研究内容,即以我国赤潮高发区东海作为主要研究海域,重点开展重要有害赤潮种的生物学特征及生态适应策略研究;近海赤潮高发区有害赤潮与富营养化的关系研究;近海赤潮高发区有害赤潮生消关键物理过程、数值模拟与预测研究;有害赤潮的危害机理及防治机理研究等。简要报道了项目通过现场综合航次获得的东海大规模赤潮发生前后水文、化学和生物学等诸多要素的变化特征,以及结合实验室模拟研究,在探索重要赤潮生物种群变化的动力学过程及其调控机理等方面取得的进展。另外,对项目的研究前景进行了展望。     

Algal blooms in a shallow lake with a special reference to lake (Loch) Lindores: Scotland

Algal blooms are frequently observed in eutrophic lakes; a typical example of which is Lake Lindores, where two species of algal blooms were observed during the studied period. The first bloom of Asterionella formosa occured in spring, with a second occurence of the bloom observed in late winter and autumn when the water temperature was fairly low. At a higher water temperature, of more than 15°C, an unwanted blue-green algal bloom of Anabaena flosaquae occured. The blue-green algal bloom normally occured in summer and early autumn.     

Blooms of Dinoflagellate Mixotrophs in a Lower Chesapeake Bay Tributary: Carbon and Nitrogen Uptake over Diurnal,Seasonal, and Interannual Timescales

A multi-year study was conducted in the eutrophic Lafayette River, a sub-tributary of the lower Chesapeake Bay during which uptake of inorganic and organic nitrogen (N) and C compounds was measured during multiple seasons and years when different dinoflagellate species were dominant. Seasonal dinoflagellate blooms included a variety of mixotrophic dinoflagellates including Heterocapsa triquetra in the late winter, Prorocentrum minimum in the spring, Akashiwo sanguinea in the early summer, and Scrippsiella trochoidea and Cochlodinium polykrikoides in late summer and fall. Results showed that no single N source fueled algal growth, rather rates of N and C uptake varied on seasonal and diurnal timescales, and within blooms as they initiated and developed. Rates of photosynthetic C uptake were low yielding low assimilation numbers during much of the study period and the ability to assimilate dissolved organic carbon augmented photosynthetic C uptake during bloom and non-bloom periods. The ability to use dissolved organic C during the day and night may allow mixotrophic bloom organisms a competitive advantage over co-occurring phytoplankton that are restricted to photoautotrophic growth, obtaining N and C during the day and in well-lit surface waters.     

Environmental Factors Contributing to the Development and Demise of a Toxic Dinoflagellate (<Emphasis Type="Italic">Karlodinium veneficum</Emphasis>) Bloom in a Shallow,Eutrophic, Lagoonal Estuary

A dense bloom of the ichthyotoxic dinoflagellate Karlodinium veneficum was discovered in the Neuse River Estuary, North Carolina, on 19 October 2006 and was associated with four subsequent fish kills. Microscopic, photopigment, DNA, and toxicological techniques confirmed bloom identity and toxicity. High-resolution spatio-temporal data from ship-board and fixed automated sampling stations provided a unique opportunity to investigate the environmental conditions that initiated, maintained, and terminated the K. veneficum bloom. Bloom initiation and growth were favored by high nutrient availability and reduced dispersal during the period of declining riverine discharge after Tropical Storm Ernesto. K. veneficum out-competed other co-occurring dinoflagellates, perhaps because of the production of karlotoxins that are known to act as grazing deterrents and to facilitate mixotrophic feeding. Once the bloom was established, small-scale hydrodynamic processes, coupled with vertical migration, concentrated cells along a frontal convergence to high densities (>200,000 cells per milliliter). By 26 October 2006, wind mixing and possible nutrient stress disrupted the bloom. Release of cell-bound toxins during the bloom collapse likely accounted for the associated fish kill events where fish were reported as exhibiting typical symptoms of karlotoxin poisoning. The dynamics of this bloom underscore the tight control of harmful algal blooms by meteorological forcing, hydrology, and sediment nutrient input in this shallow lagoonal estuary.     

Multivariate Analysis of Water Quality and Plankton Assemblages in an Urban Estuary

Raritan Bay, located between the states of New York and New Jersey, has a long history of cultural eutrophication and associated harmful algal blooms (HABs). Despite striking chemical and biological alterations occurring in Raritan Bay, publications in the early 1960s were the last to report consecutive measurements of both water quality parameters and plankton species composition in this system. The objectives of this study were to characterize water quality trends and plankton composition in a eutrophic estuary, compare current environmental conditions to those documented in Raritan Bay 50 years ago (i.e., at the same six sampling sites), and to further clarify the relationship among nutrients, secondary consumers, and algal bloom generation in this system using ordination techniques. This study (monthly data collected from April 2010–October 2012) indicates that Raritan Bay continues to exhibit numerous symptoms of eutrophication, including high algal biomass, high turbidity, violations of the dissolved oxygen standard to protect fish health, and blooms of potentially harmful phytoplankton species. Altered spatial and temporal patterns for nitrate and soluble reactive phosphorus (SRP) over the past 50 years may suggest new, changing, or expanding sources of nutrients. A total of 14 HAB species have been identified, including Heterosigma akashiwo, which formed a bloom in the upper Raritan Bay during summer 2012 in association with hypoxic conditions. Multivariate analyses indicate that abundance of this species is positively associated with high temperature, salinity, nitrate, and SRP and negatively associated with spring river discharge rates and total zooplankton abundance in Raritan Bay.     

藻类勃发—湖相油源岩形成的一种重要机制

浮游藻类是重要的湖相生油母质，本文以渤海湾盆地济阳坳陷早第三纪湖相生油岩为例，研究了其中藻类（主要是颗石藻和沟鞭藻＿化石的分布特征，并通过与现代水体中藻类生产和沉积作用的比较，探讨了生油湖泊中藻类生产和沉积方式及其对油源岩形成所起的控制作用，结果显示，藻类勃发现象在早第三纪生油湖泊中相当普遍，而且贯穿于各类油源岩的形成过程，这类快速事件性沉积是湖相油源岩形成的一种重要机制。     

Impact of the Spring 2000 phytoplankton bloom in Chesapeake Bay on optical properties and light penetration in the Rhode River,Maryland

Accelerating eutrophication manifest as increasing frequency and magnitude of phytoplankton blooms threatens living resources in many estuaries. Effects of large blooms can be difficult to document because blooms are often unexpected and do not always coincide with scheduled sampling programs. Here we use continuously monitored salinity distributions and optical properties to study the spring bloom of the red tide dinoflagellate,Prorocentrumminimum, in the Rhode River, Maryland, a tributary embayment of upper Chesapeake Bay. Salinity distributions, together with weekly cruise measurements of nutrient concentrations, indicate that the bloom commenced with an influx of nitrate at the mouth due to the arrival of a freshet from the Susquehanna River. Arrival of this freshet at the mouth set up an unstable, inverse salinity gradient within the Rhode River. Continuously monitored absorption and scattering spectra indicated that increases in chlorophyll within the Rhode River initially were due to the influx of chlorophyll that had developed in the main stem of the bay. After the influx, much higher concentrations and steep spatial gradients developed within the Rhode River, subsequent to reduced mixing that accompanied re-establishment of a normal estuarine salinity gradient. We used the monitored absorption and scattering coefficients to determine the effect of the bloom on light attenuation coefficients in the Rhode River. The bloom resulted in a nearly three-fold increase in attenuation coefficient. Attenuation was dominated by chlorophyll in the early stages of the bloom and by detritus after the termination of the bloom. Although the bloom lasted only 20 d, the elevated attenuation coefficients due to the bloom exceeded values that would permit growth of submersed vascular plants for a period of about 45 d.     

The marine killers: Dinoflagellates in estaurine and coastal waters

Records of massive fish kills and paralytic shellfish poisoning (PSP) in Europe and North America go back to the 17th century. But, it was not until the 1940s when the relationship between PSP, red tide and toxic dinoflagellateGonyaulax was established. Recent records show that PSP and related poisons caused by toxic dinoflagellates in coastal waters and estuaries, are a world-wide problem. Diarrhetic shellfish poisoning (DSP) and neurotoxic poisoning (NSP), believed earlier as bacterial or viral infections are now shown to be caused by other toxic dinoflagellates such asDinophysis. The shellfish most often involved in the poisoning are mussels and clams. Other dinoflagellates,Gyrodinium, occasionally cause massive fish kills in vast coastal areas, resulting in fishery and economic losses. Factors promoting toxic dinoflagellate bloom development and PSP/DSP outbreaks are not fully understood. In previous studies, temperature was considered as the principal factor influencing dinoflagellate blooming. Recent studies showed that other factors such as salinity, sunlight, freshwater runoff and water stability are also important. Pollution from land drainage and sewage discharge in inshore waters were also implicated. Current knowledge indicates that although chemical and biotic factors are important forin-situ growth of dinoflagellate cells, convergence by thermal and tidal fronts is essential for cell accumulation and bloom development. Advances in physical oceanographic research, modelling and remote sensing enabled the detection of fronts and bordering eddies with high precision. There is a potential for an increased use of these technological advances in predicting and monitoring the bloom development. The present paper overviews the history and distribution of toxic dinoflagellates, and the physical factors influencing bloom development and PSP/DSP outbreaks. Future research needs to improve the predictability and control of this world-wide hazard are also discussed.     

The marine killers: Dinoflagellates in estaurine and coastal waters

Records of massive fish kills and paralytic shellfish poisoning (PSP) in Europe and North America go back to the 17th century. But, it was not until the 1940s when the relationship between PSP, red tide and toxic dinoflagellateGonyaulax was established. Recent records show that PSP and related poisons caused by toxic dinoflagellates in coastal waters and estuaries, are a world-wide problem. Diarrhetic shellfish poisoning (DSP) and neurotoxic poisoning (NSP), believed earlier as bacterial or viral infections are now shown to be caused by other toxic dinoflagellates such asDinophysis. The shellfish most often involved in the poisoning are mussels and clams. Other dinoflagellates,Gyrodinium, occasionally cause massive fish kills in vast coastal areas, resulting in fishery and economic losses.Factors promoting toxic dinoflagellate bloom development and PSP/DSP outbreaks are not fully understood. In previous studies, temperature was considered as the principal factor influencing dinoflagellate blooming. Recent studies showed that other factors such as salinity, sunlight, freshwater runoff and water stability are also important. Pollution from land drainage and sewage discharge in inshore waters were also implicated.Current knowledge indicates that although chemical and biotic factors are important forin-situ growth of dinoflagellate cells, convergence by thermal and tidal fronts is essential for cell accumulation and bloom development. Advances in physical oceanographic research, modelling and remote sensing enabled the detection of fronts and bordering eddies with high precision. There is a potential for an increased use of these technological advances in predicting and monitoring the bloom development.The present paper overviews the history and distribution of toxic dinoflagellates, and the physical factors influencing bloom development and PSP/DSP outbreaks. Future research needs to improve the predictability and control of this world-wide hazard are also discussed.