Protecting small cetaceans from coastal development: Impact assessment and mitigation experience in Hong Kong     

Thomas A. Jefferson  Samuel K. Hung  Bernd Würsig 《Marine Policy》2009

Since the early 1990s, there has been an active program in Hong Kong to manage and protect local populations of small cetaceans from the effects of massive development in the area. This paper reviews the progress that has been made. Only two species regularly occur there: the Indo-Pacific humpback dolphin and the finless porpoise. Because most development has occurred in the western waters of Hong Kong, where generally only the humpback dolphin occurs, most of the work has been conducted on that species. Development of large infrastructure projects (such as airports, bridges, expressways, power plants, fuel facilities, and container ports) in Hong Kong often results in land reclamation, dredging and dumping of spoils, pipe and cable laying, percussive and bored piling work, underwater blasting, large increases in vessel traffic, and other impacts. Several mitigation measures have been used with varying levels of success, including bubble curtains/jackets, exclusion zones, ramping up of piling hammers, acoustic decoupling of noisy equipment, vessel speed limits, no-dumping policies, and silt curtains. Baseline, construction-phase, and operational-phase cetacean monitoring is often conducted to evaluate the success of conservation measures put into place. The Environmental Impact Assessment process in Hong Kong has involved cetaceans to a degree perhaps higher than anywhere else in the world, and much can be learned from studying the successes and failures of this situation.  相似文献   

Storylines: an alternative approach to representing uncertainty in physical aspects of climate change     

Theodore G. Shepherd  Emily Boyd  Raphael A. Calel  Sandra C. Chapman  Suraje Dessai  Ioana M. Dima-West  Hayley J. Fowler  Rachel James  Douglas Maraun  Olivia Martius  Catherine A. Senior  Adam H. Sobel  David A. Stainforth  Simon F. B. Tett  Kevin E. Trenberth  Bart J. J. M. van den Hurk  Nicholas W. Watkins  Dimitri A. Zenghelis 《Climatic change》2018,147(3-4):555-569

Investigating the relationships between climate extremes and crop yield can help us understand how unfavourable climatic conditions affect crop production. In this study, two statistical models, multiple linear regression and random forest, were used to identify rainfall extremes indices affecting wheat yield in three different regions of the New South Wales wheat belt. The results show that the random forest model explained 41–67% of the year-to-year yield variation, whereas the multiple linear regression model explained 34–58%. In the two models, 3-month timescale standardized precipitation index of Jun.–Aug. (SPI_JJA), Sep.–Nov. (SPI_SON), and consecutive dry days (CDDs) were identified as the three most important indices which can explain yield variability for most of the wheat belt. Our results indicated that the inter-annual variability of rainfall in winter and spring was largely responsible for wheat yield variation, and pre-growing season rainfall played a secondary role. Frequent shortages of rainfall posed a greater threat to crop growth than excessive rainfall in eastern Australia. We concluded that the comparison between multiple linear regression and machine learning algorithm proposed in the present study would be useful to provide robust prediction of yields and new insights of the effects of various rainfall extremes, when suitable climate and yield datasets are available.  相似文献   

Diamondiferous peridotitic microxenoliths from the Diavik Diamond Mine, NT     

Steven Creighton  Thomas Stachel  Hayley McLean  Karlis Muehlenbachs  Antonio Simonetti  Dave Eichenberg  Robert Luth 《Contributions to Mineralogy and Petrology》2008,155(5):541-554

Twenty-five diamonds recovered from 21 diamondiferous peridotitic micro-xenoliths from the A154 South and North kimberlite pipes at Diavik (Slave Craton) match the general peridotitic diamond production at this mine with respect to colour, carbon isotopic composition, and nitrogen concentrations and aggregation states. Based on garnet compositions, the majority of the diamondiferous microxenoliths is lherzolitic (G9) in paragenesis, in stark contrast to a predominantly harzburgitic (G10) inclusion paragenesis for the general diamond production. For garnet inclusions in diamonds from A154 South, the lherzolitic paragenesis, compared to the harzburgitic paragenesis, is distinctly lower in Cr content. For microxenolith garnets, however, Cr contents for garnets of both the parageneses are similar and match those of the harzburgitic inclusion garnets. Assuming that the microxenolith diamonds reflect a sample of the general diamond population, the abundant Cr-rich lherzolitic garnets formed via metasomatic overprinting of original harzburgitic diamond sources subsequent to diamond formation, conversion of original harzburgitic diamond sources occurred in the course of metasomatic overprint re-fertilization. Metasomatic overprinting after diamond formation is supported by the finding of a highly magnesian olivine inclusion (Fo₉₅) in a microxenolith diamond that clearly formed in a much more depleted environment than indicated by the composition of its microxenolith host. Chondrite normalized REE patterns of microxenolith garnets are predominantly sinusoidal, similar to observations for inclusion garnets. Sinusoidal REE_N patterns are interpreted to indicate a relatively mild metasomatic overprint through a highly fractionated (very high LREE/HREE) fluid. The predominance of such patterns may explain why the proposed metasomatic conversion of harzburgite to lherzolite appears to have had no destructive effect on diamond content. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

Geochemical processes underlying a sharp contrast in groundwater arsenic concentrations in a village on the Red River delta,Vietnam   总被引：1，自引：0，他引：1  

Elisabeth Eiche  Thomas Neumann  Michael Berg  Beth Weinman  Alexander van Geen  Stefan Norra  Zsolt Berner  Pham Thi Kim Trang  Pham Hung Viet  Doris Stüben 《Applied Geochemistry》2008

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Palaeo-hydrogeological control on groundwater As levels in Red River delta,Vietnam     

Søren Jessen  Flemming Larsen  Dieke Postma  Pham Hung Viet  Nguyen Thi Ha  Pham Quy Nhan  Dang Duc Nhan  Mai Thanh Duc  Nguyen Thi Minh Hue  Trieu Duc Huy  Tran Thi Luu  Dang Hoang Ha  Rasmus Jakobsen 《Applied Geochemistry》2008

To study the geological control on groundwater As concentrations in Red River delta, depth-specific groundwater sampling and geophysical logging in 11 monitoring wells was conducted along a 45 km transect across the southern and central part of the delta, and the literature on the Red River delta’s Quaternary geological development was reviewed. The water samples (n = 30) were analyzed for As, major ions, Fe²⁺, H₂S, NH₄, CH₄, δ¹⁸O and δD, and the geophysical log suite included natural gamma-ray, formation and fluid electrical conductivity. The SW part of the transect intersects deposits of grey estuarine clays and deltaic sands in a 15–20 km wide and 50–60 m deep Holocene incised valley. The NE part of the transect consists of 60–120 m of Pleistocene yellowish alluvial deposits underneath 10–30 m of estuarine clay overlain by a 10–20 m veneer of Holocene sediments. The distribution of δ¹⁸O-values (range −12.2‰ to −6.3‰) and hydraulic head in the sample wells indicate that the estuarine clay units divide the flow system into an upper Holocene aquifer and a lower Pleistocene aquifer. The groundwater samples were all anoxic, and contained Fe²⁺ (0.03–2.0 mM), Mn (0.7–320 μM), SO₄ (<2.1 μM–0.75 mM), H₂S (<0.1–7.0 μM), NH₄ (0.03–4.4 mM), and CH₄ (0.08–14.5 mM). Generally, higher concentrations of NH₄ and CH₄ and low concentrations of SO₄ were found in the SW part of the transect, dominated by Holocene deposits, while the opposite was the case for the NE part of the transect. The distribution of the groundwater As concentration (<0.013–11.7 μM; median 0.12 μM (9 μg/L)) is related to the distribution of NH₄, CH₄ and SO₄. Low concentrations of As (?0.32 μM) were found in the Pleistocene aquifer, while the highest As concentrations were found in the Holocene aquifer. PHREEQC-2 speciation calculations indicated that Fe²⁺ and H₂S concentrations are controlled by equilibrium for disordered mackinawite and precipitation of siderite. An elevated groundwater salinity (Cl range 0.19–65.1 mM) was observed in both aquifers, and dominated in the deep aquifer. A negative correlation between aqueous As and an estimate of reduced SO₄ was observed, indicating that Fe sulphide precipitation poses a secondary control on the groundwater As concentration.  相似文献   

Applicability of CPT-based methods in predicting toe bearing capacities of driven piles in sand     

Le Chi Hung  Tien Dung Nguyen  Ju-Hyung Lee  Sung-Ryul Kim 《Acta Geotechnica》2016,11(2):359-372

This paper presents a study on applicability of predicting toe bearing capacities from cone penetration test (CPT) for PHC (pretensioned spun high-strength concrete) driven piles into deep sandy deposits in the Nakdong River deltaic area west of Busan City in South Korea. Using toe bearing capacities obtained from pile driving analyzer (PDA) tests as reference values, which were reliably calibrated by on-site O-cell tests, the applicability of the CPT-based methods was evaluated using a statistical rank index (RI). A total of 82 piezocone penetration test soundings and 190 PDA test piles were used for reliability analysis in this study. Three correction steps were applied to obtain reliable PDA and CPT data sets before ranking is carried out. The RI index is combined from four criteria: (1) the best-fit line, (2) the arithmetic mean and standard deviation, (3) the cumulative probabilities, and (4) the log-normal and histogram distributions. Based on these criteria the performance of some SPT-based methods in the literature is evaluated.  相似文献   

COMMENTS ON FRONTIERS IN GEOGRAPHICAL TEACHING     

F. Hung 《The Professional geographer》1966,18(6):341-345

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Sublethal toxicity of orchard stormwater runoff in Sacramento splittail (Pogonichthys macrolepidotus) larvae     

Teh SJ  Deng D  Werner I  Teh F  Hung SS 《Marine environmental research》2005,59(3):203-216

The sublethal effects of stormwater runoff from sections of a plum orchard treated with esfenvalerate or diazinon were evaluated in 7-day-old Sacramento splittail (Pogonichthys macrolepidotus) larvae. Fish were exposed to eight runoff samples using the USEPA standard static renewal method for 96 h acute toxicity testing, then transferred to clean water for three-month to assess the survival, growth, histopathological abnormalities, and heat stress proteins (hsp). No significant mortality was observed at 96 h in exposed fish. At one week, histopathological abnormalities included severe glycogen depletion, cytoplasmic protein droplets, vacuolar degeneration, and cell necroses in liver of all exposure groups. Pyknotic nerve cells were seen in brain of one exposure group. Significantly higher cumulative mortality, lower condition factor, and elevated hsp60 and hsp70 levels (p < 0.05) were occurred in several exposure groups. No histopathological abnormalities were observed after three months in any exposure group. This study confirms that standard acute toxicity tests have underestimated the toxicity of stormwater runoff, and although splittail larvae survived the 96 h exposure, they exhibited reduced survival and growth and showed signs of cellular stress even after a three month recovery period.  相似文献   

Binding of thorium(IV) to carboxylate, phosphate and sulfate functional groups from marine exopolymeric substances (EPS)   总被引：2，自引：0，他引：2  

Nicols G. Alvarado Quiroz  Chin-Chang Hung  Peter H. Santschi 《Marine Chemistry》2006,100(3-4):337

Th(IV) isotopes are important proxies in oceanographic investigations, and are used as tracers of particle dynamics and particulate organic matter (POC) fluxes out of the euphotic zone through the use of ²³⁴Th/POC ratios. These approaches rely on empirically determined and variable POC to ²³⁴Th ratios, which might be controlled, in parts, by the abundance of exopolymeric substances (EPS). EPS contain acidic polysaccharides (APS) and are excreted by both phytoplankton and bacteria. To this end, radiotracer experiments with EPS from microbial cultures were conducted to determine the binding environment of ²³⁴Th(IV)-binding ligands in colloids and suspended particles in marine systems. In these experiments, the ²³⁴Th distribution during isoelectric focusing (IEF) and polyacrylamide gel electrophoresis (PAGE) was related to the functional group composition of EPS and of colloidal organic matter (COM) isolated from the Gulf of Mexico (GOM) using cross-flow ultrafiltration. EPS was extracted from phytoplankton (Emiliania huxleyi and Synechococcus elongatus) and bacteria (Sagittula stellata and Roseobacter gallaeciensis) cultures by repeated alcohol precipitation. Phosphate and sulfate concentrations were determined using ion chromatography (IC). IEF profiles indicated that 49% to 65% of the ²³⁴Th-labeled EPS from plankton and bacteria as well as COM samples from the GOM was found concentrated below pH of 4, near an isoelectric point, pH_IEP, of about 2. The carboxylic acid maxima for extracted EPS and COM samples appeared close to the pH_IEF of ²³⁴Th(IV). The phosphate maximum appeared at the same pH_IEF as ²³⁴Th(IV) for EPS from R. gallaeciensis and S. elongatus. The sulfate maximum was found at the same pH_IEF as ²³⁴Th(IV) for EPS from S. elongatus and COM. The molecular weight (MW) of the strongly Th(IV)-binding ligand varied from 1 to 14 kDa, depending on the species, but was about 10 kDa in COM. Thus, depending on the species of plankton or bacteria, the MW and specific functional group composition of the strongly ²³⁴Th(IV)-binding amphiphilic biomolecule can vary. Therefore, different acidic functional groups can, at times, contribute to the binding of Th(IV) to the EPS chelating ligand, which can also have different MWs. This implies that the binding environment for Th(IV), which is present at total concentrations at least a million times lower than the acid functional groups, consists of strong polydentate chelate complexes in clustered structures of carboxylate, sulfates and/or phosphates. The combination of strongly chelating groups and amphiphilicity gives this biomolecule the unique properties of a “sticky” ligand.  相似文献   

Primary production in the Kuroshio current surrounding Taiwan     

Tsu-Chang Hung 《Journal of Oceanography》1975,31(6):255-258

Primary production in the Kuroshio current flowing around Taiwan Island was measured by using the radiocarbon method. High values of the daily primary production were found in both the aquacultural area at the western coast and the polluted area with raw rubbish heaps at the Keelung-Patoutzu coast. In the upwelling region of southeastern coast, low values of the primary production were observed. In the eastern coast, the rate of photosynthesis for an unit amount of chlorophylla under the saturated light was in the range of 1.2±0.2 mg C/mg chlorophylla/hr. Some discussions are made on the observed results.  相似文献