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1.
T. Y. Lee J. C. Huang L. Y. Liao C. S. Tzeng C. H. Yang P. K. Kalita C. P. Tung 《水文研究》2012,26(24):3635-3644
Reducing or stabilizing the stream temperature of ChiChiaWan Creek is a crucial work for Formosan Landlocked Salmon because ChiChiaWan Creek is the only one habitat for this endangered species. Planting trees in the riparian zone would be one of the alternatives. The purpose of this study was to evaluate the effects of several planting strategies on daily maximum stream temperature along the river. The results showed the effective vegetative shading angles should be more than 50° along ChiChiaWan Creek to reduce the direct solar radiation heating effectively. Upstream planting with 70° vegetative shading angle could be the most effective way among all the scenarios. However, this planting strategy could not improve the worst situations in summer because of the large solar elevation angles. The upstream planting in ChiChiaWan Creek was strongly recommended because the canopies could be easier to extend to totally cover the narrow width of river producing the most effective shades. Practicing the upstream planting with 90° vegetative shading angle can increase more than 1 km long suitable habitats for the endangered Salmon in summer. Alternatively, the west‐side planting scenario was the second effective way for temperature reduction. Our result provided a useful suggestion for the authorities in charge of saving the Formosan Landlocked Salmon, particularly under the stress of global warming. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
2.
Ching-Yaw Tzeng 《Oceanic Engineering, IEEE Journal of》1999,24(4):507-513
This technical communication is concerned with the design of inland ship-steering autopilots characterized by turning rate regulation rather than heading regulation found on most ocean-going vessel autopilots. The autopilot design is based on the internal model control approach which allows clear connections between the controller structure and that of the ship model to be established. To fully utilize the limited rudder power without introducing the controller wind-up, which may lead to undesirable long transients, an inverse of the rudder saturation (SAT) and slew rate limitation (SRL) is implemented in the controller. Specifically, an inversion by feedback technique is employed by implementing the noninverted dynamics in a local feedback loop. This resolves the difficulty associated with inversion of the SAT and SRL mathematically. Consequently, high turning rate maneuver can be achieved in case of emergency encounters without causing the controller wind-up. This feature is particularly important for inland ships, since unexpected encounters with other ships are quite common and the capability of quick response is vital to ensure safe maneuvers 相似文献
3.
Summary The global-scale intraseasonal and annual variations of divergent water-vapor transport and water vapor itself were examined by using outgoing longwave radiation (OLR) and data for 1979–1986 produced by the Global Data Assimilation System of the National Meteorological Center. An effort was also made to contrast results of this study with previous analyses of OLR and upper-level divergent circulation.As for intraseasonal oscillation, positive (negative) precipitable-water (W) anomalies and negative (positive) OLR couple with the convergent (divergent) center of the potential function of water vapor transport () anomalies and the divergent (convergent) center of upper-level divergent-circulation anomalies. It is inferred that the eastward-propagating divergent circulation of intraseasonal oscillation converges water vapor to maintain cumulus convection, which releases latent heat, possibly to support this low-frequency oscillation. Fluctuations of W and cumulus convection associated with this oscillation are large over the equatorial Indian Ocean and the equatorial western Pacific, but small over the tropical Americas and equatorial Africa. Moreover, during northern summer, W anomaly bands migrate regularly northward, following the low-level transient 30–50 day monsoon troughs and ridges over the northern Indian Ocean. To the south of the equator, a regular southward propagation of W anomaly bands is identified in both northern summer and winter. In contrast; over the northwestern Pacific, a signature depicting the north-south intraseasonal oscillation of the north Pacific Convergence Zone can be inferred by W anomalies.The annual cycle components of W and cumulus convection inferred from OLR anomalies exhibit three pairs of maximum-minimum centers over tropical continents. These centers correspond to those of and upper-level divergent circulation anomalies. It is shown that landmass cooling in the winter hemisphere and landmass warming in the summer hemisphere establish a pair of upper-level convergent-divergent centers over each tropical continent. Water vapor is converged (diverged) by divergent circulation, in order to maintain maximum (minimum) centers of W and cumulusconvection anomalies over each tropical continent.With 7 Figures 相似文献
4.
Hsien-Tang Tsai Cheng-Jui Tseng Shian-Yang Tzeng Tung-Ju Wu Jen-der Day 《Natural Hazards》2012,62(1):83-91
Typhoon Morakot hit Taiwan in 2009, severely damaging the Alishan National Forest Recreation Area, a famous tourist resort
in Taiwan. The only highway to this area was under repair for 10 months after the typhoon. Consequently, Alishan’s tourism
industry suffered losses estimated at NT$1 billion. This work investigates the impacts of natural hazards on Taiwan’s tourism
industry. First, government, university, and industry experts were invited to a focus-group interview to update criteria for
tourism development in Taiwan. Next, the Analytic Hierarchy Process (AHP) was applied to rank the proposed criteria. Last,
two tourist attractions, one urban and one rural, are discussed in detail. This work proposes three novel dimensions for Taiwan’s
tourism development—destination attraction, destination arrangement, and contingency planning for natural hazards—which comprise
nine criteria. Analytical results will provide Taiwan’s tourism industry with references for future policy-making and sustainable
development. 相似文献
5.
H. Aghababaee J. Amini Y. C. Tzeng J. T. Sri Sumantyo 《Journal of the Indian Society of Remote Sensing》2013,41(4):739-747
The paper presents an effective way of detecting the changes of multi-temporal synthetic aperture radar (SAR) images. An accurate unsupervised change detection method that combines the intensity information and the fractal dimension of SAR images is proposed based on the fractal genetic model (FGM). The model computes firstly the local fractal dimension of the SAR images to obtain the fractal image and next a new proposed measure (D) is calculated from the normalized ratio of SAR images and the normalized difference of fractal images. Finally, the change map is derived by minimizing a cost function using a genetic algorithm (GA) on the derived image from the measure. Experimental results of detecting changes from SAR images acquired by ASAR on board ENVISAT and ALOS-PALSAR reveal that the proposed method is an effective and efficient tool for change detection from SAR images. 相似文献
6.
Chung-Ming Liu Ming-Chin Wu Sahana Paul Ying-Chen Chen Shu-Hua Lin Wei-Shiang Lin Yen-Chih Lee Huang-Hsung Hsu Ren-Yow Tseng Cheng-Ta Chen 《Theoretical and Applied Climatology》2011,103(1-2):265-278
Runs of three regional climate models (RCMs) dynamically downscaling the outputs of atmosphere?Cocean coupling general circulation models (AOGCMs) are studied. These RCMs are NCAR-MM5, NCEP-RSM (Regional Spectral Model), and Purdue-PRM (Purdue Regional Model). A useful approach is developed to compare the variability, error, and spatial distribution of model-simulated results with respect to the Climatic Research Unit (CRU) datasets over East Asia and seven sub-regions during the 1990s. The results show that NCEP-RSM outperforms the other two in meeting criteria selected on evaluating the model performance. Furthermore, three super-ensemble approaches are tested on merging RCMs?? outputs. The inverse of the square error summation (ISES) method is selected as a suitable method with a generally good performance during the verification period. The projected future climate changes by ISES indicate larger temperature increases over high-latitude continent and smaller over low-latitude maritime areas. Rainfall will increase in summer over the central simulation domain, i.e. the eastern China, but decrease in winter, which are clearly linked to the variation in the synoptic airflows. Also, a more frequent occurrence of extreme rainfall events than what happened in the 1990s is projected. The projection over Taiwan suggests strong warming in summer, followed by autumn, winter, and spring. The interaction between the synoptic flow and the local terrain affects significantly the changes in precipitation. In general, larger change of the variability of rainfall will be over areas with lesser rainfall in the future, while lesser change will be over areas with more projected rainfall. 相似文献
7.
A massive fish kill of approximately 50 tons of flathead grey mullet (Mugil cephalus) occurred in August 2006 in the Tanshui River, northern Taiwan. To clarify the origin of these mullets, 42 individuals were randomly collected to determine their ages by reading otolith annuli and to measure the trace elements in the otolith. The total lengths of the fish averaged 32.7 ± 4.4 cm, and most of the individuals were 2 years old, indicating that the mullets in the mass fish kill event were in the immature and growth stages. The Sr/Ca and Ba/Ca ratios of a subsample of 14 otoliths showed that half of the fish killed were estuarine residents, and the rest originated from marine and freshwater habitats. The multiple causes involved in this fish kill implied that additional unknown factors influenced the mullet populations on a large scale and induced them to move quickly and gather at this estuary. 相似文献
8.
Tzu‐Yi Pai Terng‐Jou Wan Yung‐Pin Tsai Chwen‐Jeng Tzeng Hsiao‐Hsing Chu Yao‐Sheng Tsai Ching‐Yuan Lin 《洁净——土壤、空气、水》2010,38(2):167-172
In this study, the effect of sludge retention time on ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) in an anaerobic/oxic (AO) process, was explored. The results indicated that the growth rate constants of AOB were 0.97, 0.88, and 0.79 d–1, respectively, meanwhile, those of NOB were 1.22, 1.03, and 0.93 d–1, respectively, when the sludge retention time (SRT) was 15 days, 10 days and 5 days. The relation between the growth rate constant and the SRT could be best described using a simple exponential curve and a second type hyperbolic curve. The lysis rate constants for AOB and NOB were 0.13 and 0.18 d–1, respectively. The yield coefficients values of AOB and NOB were 0.22 and 0.21, respectively. The percentage of AOB to mixed liquid suspended solids (MLSS) was 0.64%, 0.53%, and 0.35%, respectively. Meanwhile, the percentage of NOB was 2.24%, 1.87%, and 1.11%, respectively, at SRT values of 15 days, 10 days and 5 days. When the SRT value decreased, the AOB and NOB biomass levels decreased by 12.75 and 47.01 mg L–1, respectively. Meanwhile the removal efficiency of NH4+‐N decreased from 90 to 26%, while the removal efficiency of total nitrogen (TN) decreased from 14 to 8%. 相似文献
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10.
Living on the edge: feeding of subtropical open ocean copepods 总被引：2，自引：0，他引：2
The objective of this study was to provide quantitative information on environmental feeding rates of warm water oceanic epipelagic copepods. We determined clearance rates at 23 °C for various particle size ranges in shipboard studies in the western oligotrophic subtropical Atlantic Ocean for females of the calanoid species Clausocalanus furcatus and Mecynocera clausii. These in situ clearance rates were then applied to the various particle size ranges of environmental particle spectra of auto‐ and heterotrophs at different depths from three stations in the western Atlantic. After calculating the metabolic demands of each of these two copepod species and applying an assimilation efficiency of 90%, we determined that C. furcatus meets its metabolic demands in all six cases, and M. clausii in two of six cases. Clausocalanus furcatus would also meet its energy demands at 25 °C, where it is often found, while M. clausii at 20 °C, where it is regularly found, would cover its metabolic needs in four of six cases. It is hypothesized that these species, and most likely most of the other co‐occurring copepod species, are limited in their abundance by food availability, or, better said, are ‘living on the edge’ in relation to food abundance. 相似文献