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Sustainable management of coastal and coral reef environments requires regular collection of accurate information on recognized ecosystem health indicators. Satellite image data and derived maps of water column and substrate biophysical properties provide an opportunity to develop baseline mapping and monitoring programs for coastal and coral reef ecosystem health indicators. A significant challenge for satellite image data in coastal and coral reef water bodies is the mixture of both clear and turbid waters. A new approach is presented in this paper to enable production of water quality and substrate cover type maps, linked to a field based coastal ecosystem health indicator monitoring program, for use in turbid to clear coastal and coral reef waters. An optimized optical domain method was applied to map selected water quality (Secchi depth, Kd PAR, tripton, CDOM) and substrate cover type (seagrass, algae, sand) parameters. The approach is demonstrated using commercially available Landsat 7 Enhanced Thematic Mapper image data over a coastal embayment exhibiting the range of substrate cover types and water quality conditions commonly found in sub-tropical and tropical coastal environments. Spatially extensive and quantitative maps of selected water quality and substrate cover parameters were produced for the study site. These map products were refined by interactions with management agencies to suit the information requirements of their monitoring and management programs. 相似文献
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Schroeder T Devlin MJ Brando VE Dekker AG Brodie JE Clementson LA McKinna L 《Marine pollution bulletin》2012,65(4-9):210-223
Riverine freshwater plumes are the major transport mechanism for nutrients, sediments and pollutants into the Great Barrier Reef (GBR) lagoon and connect the land with the receiving coastal and marine waters. Knowledge of the variability of the freshwater extent into the GBR lagoon is relevant for marine park management to develop strategies for improving ecosystem health and risk assessments. In this study, freshwater extent has been estimated for the entire GBR lagoon area from daily satellite observations of the Moderate Resolution Imaging Spectroradiometer (MODIS) between 2002 and 2010. To enable a reliable mapping of freshwater plumes we applied a physics-based coastal ocean colour algorithm, that simultaneously retrieves chlorophyll-a, non-algal particulate matter and coloured dissolved organic matter (CDOM), from which we used CDOM as a surrogate for salinity (S) for mapping the freshwater extent. 相似文献
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Kennedy K Schroeder T Shaw M Haynes D Lewis S Bentley C Paxman C Carter S Brando VE Bartkow M Hearn L Mueller JF 《Marine pollution bulletin》2012,65(4-9):292-305
Photosystem II (PSII) herbicides are used in large quantities on agricultural lands adjoining the Great Barrier Reef (GBR). Routine monitoring at 14 sites in inshore waters of the GBR using passive sampling techniques detected diuron (32-94% of sampling periods) at maximum concentrations of 1.7-430ng L(-1) in the relatively pristine Cape York Region to the Mackay Whitsunday Region, respectively. A PSII herbicide equivalent (PSII-HEq) index developed as an indicator for reporting was dominated by diuron (average contribution 89%) and typically increased during the wet season. The maximum PSII-HEq indicates the potential for photosynthetic inhibition of diatoms, seagrass and coral-symbionts. PSII herbicides were significantly positively correlated with remotely sensed coloured dissolved organic matter, a proxy for freshwater extent. Combining these methods provides for the first time the potential to cost-effectively monitor improvements in water quality entering the GBR with respect to exposure to PSII herbicides. 相似文献
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This paper deals with experimental tests aimed at assessing the structural performance of pure aluminium shear panels to be employed as passive energy dissipation devices with a bracing type configuration. The AW1050 A H24 is adopted as the basic material. It is an aluminium alloy with a negligible content of impurity, allowing it to be considered as a pure aluminium. In this paper, the results of four full‐scale 5thinspacemm thick multi‐stiffened square‐shaped specimens tested under cyclic diagonal loads and characterized by different slenderness ratios are presented. In order to determine the main resisting mechanisms for different shear strain demands, a careful examination of the experimental evidences is provided. Then, the global performance of tested shear panels is evaluated by the comparison of the obtained hysteretic responses, evidencing the effect of the plate slenderness on the energy dissipation capacity. Finally, a suitable analytical model, which could be useful to implement global dynamic non‐linear analysis, is set up in order to interpret the behaviour of shear panels for which the development of premature buckling phenomena is completely inhibited. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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THE ROLE OF ATMOSPHERIC CIRCULATION PATTERNS IN AGROCLIMATE VARIABILITY IN FINLAND, 1961–2011 
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下载免费PDF全文 MASOUD IRANNEZHAD DELIANG CHEN BJØRN KLØVE 《Geografiska Annaler: Series A, Physical Geography》2016,98(4):287-301
This study evaluates interannual variations and trends in growing season daily temperature sum and daily precipitation sum in Finland during 1961–2011, and their connections to well known atmospheric circulation patterns. Changes in summer (June–August) climate partially explain changes in growing season daily temperature sum and daily precipitation sum over Finland, which naturally decreased from south to north. On a national scale, growing season warmed and became wetter during 1961–2011, as growing season daily temperature sum and daily precipitation sum significantly (p < 0.05) increased by 5.01 ± 3.17°C year–1 and 1.39 ± 0.91 mm year–1, respectively. The East Atlantic pattern was the most influential atmospheric circulation pattern for variations in growing season daily temperature sum (rho = 0.40) across Finland and the East Atlantic/West Russia pattern was most influential for growing season daily precipitation sum variability (rho = –0.54). There were significant (p < 0.05) increasing trends in growing season daily temperature sum and daily precipitation sum throughout Finland during 1961–2011. Increased growing season daily temperature sum was mainly observed in northern, central, western, eastern and coastal areas of south‐western Finland. This warming was positively associated with the East Atlantic pattern in the north, centre and south, but negatively associated with the East Atlantic/West Russia pattern in eastern Finland. Increased GSP mostly occurred in southern, eastern, western, central, northern and north‐western Finland. These wetting trends were positively correlated with the East Atlantic pattern in the north and negatively correlated with the Polar pattern in the south and the East Atlantic/West Russia pattern in the east, west, centre and north‐east of Finland. The overall agroclimatic year‐to‐year variability in Finland between 1961 and 2011 was mostly linked to variations in the East Atlantic and East Atlantic/West Russia patterns. 相似文献
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JEAN CHALINE GENEVIèVE FARJANEL 《Boreas: An International Journal of Quaternary Research》1990,19(1):69-80
Five new palynological sequences in the Bresse valley (France), covering Reuverian, Praetiglian, Tiglian and Eburonian-Waalian times, yielded rodent teeth of the Mimomys occitanus-savini lineage evolving in Eurasia by phyletic gradualism. For the first time the west European palynological zonation is correlated with the Eurasiatic rodent one, leading to the following attributions: Mimomys occitanus: Reuverian; Mimomys polonicus : Praetiglian to early Tiglian; Mimomyspliocaenicus : Tiglian; Mimomys ostramosensis: Eburonian to early Waalian; Mimomys savini occurring from Waalian to Cromerian. As a result, the Neogene biozones MN15 to MN17 can be defined by nine new subdivisions. 相似文献
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