Soil erosion susceptibility assessment and validation using a geostatistical multivariate approach: a test in Southern Sicily   总被引：2，自引：0，他引：2  

Christian Conoscenti  Cipriano Di Maggio  Edoardo Rotigliano 《Natural Hazards》2008,46(3):287-305

A certain number of studies have been carried out in recent years that aim at developing and applying a model capable of assessing water erosion of soil. Some of these have tried to quantitatively evaluate the volumes of soil loss, while others have focused their efforts on the recognition of the areas most prone to water erosion processes. This article presents the results of a research whose objective was that of evaluating water erosion susceptibility in a Sicilian watershed: the Naro river basin. A geomorphological study was carried out to recognize the water erosion landforms and define a set of parameters expressing both the intensity of hydraulic forces and the resistance of rocks/soils. The landforms were mapped and classified according to the dominant process in landsurfaces affected by diffuse or linear water erosion. A GIS layer was obtained by combining six determining factors (bedrock lithology, land use, soil texture, plan curvature, stream power index and slope-length factor) in unique conditions units. A geostatistical multivariate approach was applied by analysing the relationships between the spatial distributions of the erosion landforms and the unique condition units. Particularly, the density of eroded area for each combination of determining factors has been calculated: such function corresponds, in fact, to the conditional probability of erosion landforms to develop, under the same geoenvironmental conditions. In light of the obtained results, a general geomorphologic model for water erosion in the Naro river basin can be depicted: cultivated areas in clayey slopes, having fine-medium soil texture, are the most prone to be eroded; linear or diffuse water erosion processes dominate where the topography is favourable to a convergent or divergent runoff, respectively. For each of the two erosion process types, a susceptibility map was produced and submitted to a validation procedure based on a spatial random partition strategy. Both the success of the validation procedure of the susceptibility models and the geomorphological coherence of the relationships between factors and process that such models suggest, confirm the reliability of the method and the goodness of the predictions.  相似文献   

Etude du regime alimentaire de l'Aigle de mer, Myliobatis aquila (L., 1758) des cotes tunisiennes     

Christian  Capape 《ICES Journal of Marine Science》1976,37(1):29-35

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对应分析在法国Douarnenez海湾拟庸鲽食性研究中的应用(Ⅱ)     

林学群  ChristianDENIEL  AlainLAUREC  FranoiseLEMENN 《海洋科学》1994,18(1):29-32

２．４拟庸蝶食性的对应分析２．４．１观察量和变量的分组观察量（捕食鱼类）依不同季节（冬、夏季）、不同性别（雌雄性）和不同性成熟状态（幼鱼和成鱼）来分组，因此得到８（２３）个观察量。对应分析的变量（饵料）首先根据个体生态的不同分为６个类型：游走多毛类，隐居多毛类，双壳类，不大游动的甲壳类（端足目和等足目），爬行甲壳类（十足国短尾部）和棘皮动物。其他６个类型的饵料生物（类、纽虫类、小型游泳甲壳类、腔肠动物、鱼类及苔藓虫类顺在分组时剔除，其原因为它们的出现可能少了些。考虑到捕食鱼类和饵料双壳类贝壳厚度…  相似文献   

Ecology of the Symbiotic Coral Cladocora caespitosa (L.) (Faviidae, Scleractinia) in the Bay of Piran (Adriatic Sea): II. Energy Budget     

Christian  Schiller 《Marine Ecology》1993,14(3):221-238

Abstract. The temperate, symbiotic coral Cladocora caespitosa occurs naturally with variable numbers of zooxanthellae. This allows us to study differences in the physiology of symbiotic and "non-symbiotic" polyps and to correlate them with zooxanthellae activities.
Zooxanthellae density in "dark" (normal-colored) polyps was 50 times higher than in "white" (bleached) polyps.
The chlorophyll a content per zooxanthella was 3 times, and Chi c was 13 times higher in white polyps than in dark ones. O₂-flux experiments were conducted with colonies in situ and with single polyps - dark and white - under laboratory conditions. Two approaches were used to evaluate the contribution of zooxanthellae translocation products to animal respiration. Both revealed that the animal tissues derive a higher benefit from the zooxanthellae during periods of low water temperature than during warm periods.  相似文献   

Particle Analysis in Oceanography.     

Christian  Schiller 《Marine Ecology》1994,15(2):175-176

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Viability theory for an ecosystem approach to fisheries   总被引：1，自引：1，他引：1  

Cury  Philippe M.; Mullon  Christian; Garcia  Serge M.; Shannon  Lynne J. 《ICES Journal of Marine Science》2005,62(3):577-584

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“Coastal dynamics and human impact: south-eastern North Sea”, an overview     

Christian Winter  Alexander Bartholomä 《Geo-Marine Letters》2006,26(5):303-303

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Spring diet of ringed seals (Phoca hispida) from northwestern Spitsbergen, Norway     

Labansen  Aili L.; Lydersen  Christian; Haug  Tore; Kovacs  Kit M. 《ICES Journal of Marine Science》2007,64(6):1246-1256

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SeagrassNet monitoring across the Americas: case studies of seagrass decline   总被引：2，自引：0，他引：2  

Frederick T. Short  Evamaria W. Koch  Joel C. Creed  Karine M. Magalhães  Eric Fernandez  & Jeffrey L. Gaeckle 《Marine Ecology》2006,27(4):277-289

Seagrasses are an important coastal habitat worldwide and are indicative of environmental health at the critical land–sea interface. In many parts of the world, seagrasses are not well known, although they provide crucial functions and values to the world's oceans and to human populations dwelling along the coast. Established in 2001, SeagrassNet, a monitoring program for seagrasses worldwide, uses a standardized protocol for detecting change in seagrass habitat to capture both seagrass parameters and environmental variables. SeagrassNet is designed to statistically detect change over a relatively short time frame (1–2 years) through quarterly monitoring of permanent plots. Currently, SeagrassNet operates in 18 countries at 48 sites; at each site, a permanent transect is established and a team of people from the area collects data which is sent to the SeagrassNet database for analysis. We present five case studies based on SeagrassNet data from across the Americas (two sites in the USA, one in Belize, and two in Brazil) which have a common theme of seagrass decline; the study represents a first latitudinal comparison across a hemisphere using a common methodology. In two cases, rapid loss of seagrass was related to eutrophication, in two cases losses related to climate change, and in one case, the loss is attributed to a complex trophic interaction resulting from the presence of a marine protected area. SeagrassNet results provide documentation of seagrass change over time and allow us to make scientifically supported statements about the status of seagrass habitat and the extent of need for management action.  相似文献   

Baltic cod recruitment - the impact of climate variability on key processes   总被引：3，自引：0，他引：3  

Koster  Friedrich W.; Mollmann  Christian; Hinrichsen  Hans-Harald; Wieland  Kai; Tomkiewicz  Jonna; Kraus  Gerd; Voss  Rudiger; Makarchouk  Andrei; MacKenzie  Brian R.; St. John  Michael A.; Schnack  Dietrich; Rohlf  Norbert; Linkowski  Tomasz; Beyer  Jan E. 《ICES Journal of Marine Science》2005,62(7):1408-1425

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