Development of regional design hyetographs     

Gwo‐Fong Lin  Lu‐Hsien Chen  Shih‐Chieh Kao 《水文研究》2005,19(4):937-946

A method is proposed to establish regional design hyetographs for facilitating the determination of design hyetographs at ungauged sites. The method is applied to the central area of Taiwan. First, the single‐station design hyetographs at all rain gauges are analysed using principal components analysis and cluster analysis. The principal components analysis shows that there are six dominant factors, and the cluster analysis indicates that the time to peak rainfall has the largest influence on the classification of hyetographs. It also shows that the single‐station hyetographs in the study area can be classified into three clusters. Finally, the homogeneous regions for these three clusters are delineated and the corresponding regional design hyetographs are proposed. Once the homogeneous regions and the regional hyetographs are available, the design hyetograph at the point of interest can be easily determined. The proposed method is expected to be useful for providing the design hyetographs at ungauged sites. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

Bioremediation of 2,4,6-trinitrotoluene-contaminated groundwater using unique bacterial strains: microcosm and mechanism studies     

Y. T. Sheu  P. J. Lien  C. C. Chen  Y. M. Chang  C. M. Kao 《International Journal of Environmental Science and Technology》2016,13(5):1357-1366

Groundwater at many military factory, munition storage and maneuver sites is contaminated by explosives chemicals that were released into the subsurface. The 2,4,6-trinitrotoluene (TNT) is among the most common explosive pollutants. In this study, two TNT-degrading strains, isolated from TNT-contaminated soils and wastewater sludge, were applied for TNT biodegradation. Based on the 16S rDNA sequence analyses, these two bacterial strains were identified as Achromobacter sp. and Klebsiella sp. via biochemical and DNA analyses. Microcosm study was conducted to evaluate the feasibility and efficiency of TNT biodegradation under aerobic conditions. Results indicate that TNT degradation by-products were detected in microcosms (inoculated with Achromobacter sp. and Klebsiella sp.) with cane molasses addition. Klebsiella sp. and Achromobacter sp. used TNT as the nitrogen source and caused completely removal of TNT. Two possible TNT biodegradation routes could be derived: (1) part of the TNT was transformed to nitrotoluene then transformed to nitrobenzene followed by the nitro substitute process, and trinitrobenzene, dinitrobenzene, and nitrobenzene were detected; and (2) TNT was transformed via the nitro substitute mechanism, and dinitrotoluene followed by nitrotoluene isomers were detected. The initial TNT degradation involved the reduction or removal of the nitro substitute to an amino derivative or free nitrite. Results show that the second route was the dominant TNT biodegradation pathway. The produced by-products were also degraded without significant accumulation during the degradation process. These findings would be helpful in designing a practical system inoculated with isolated TNT degradation strains for the treatment of TNT-contained groundwater.  相似文献   

Enabling maps/location searches on mobile devices: constructing a POI database via focused crawling and information extraction     

Hsiu-Min Chuang  Ting-Yao Kao  Chung-Ting Cheng  Ya-Yun Huang  Kuo-Pin Cheong 《International journal of geographical information science》2016,30(7):1405-1425

With the popularity of mobile devices and smartphones, we have witnessed rapid growth in mobile applications and services, especially in location-based services (LBS). According to a mobile marketing survey, maps/location searches are among the most utilized services on smartphones. Points of interest (POIs), such as stores, shops, gas stations, parking lots, and bus stops, are particularly important for maps/location searches. Existing map services such as Google Maps and Wikimapia are constructed manually either professionally or with crowd sourcing. However, manual annotation is costly and limited in current POI search services. With the abundance of information on the Web, many store POIs can be extracted from the Web. In this paper, we focus on automatically constructing a POI database to enable store POI map searches. We propose techniques that are required to construct a POI database, including focused crawling, information extraction, and information retrieval techniques. We first crawl Yellow Page web sites to obtain vocabularies of store names. These vocabularies are then investigated with search engines to obtain sentences containing these store names from search snippets in order to train a store name recognition model. To extract POIs scattered across the Web, we propose a query-based crawler to find address-bearing pages that might be used to extract addresses and store names. We crawled 1.25 million distinct POI pairs scattered across the Web and implemented a POI search service via Apache Lucent’s search platform, called Solr. The experimental results demonstrate that the proposed geographical information retrieval model outperforms Wikimapia and a commercial app called ‘What’s the Number?’  相似文献   

A Review on Hydraulic Fracture Height Growth for Layered Formation     

Tan  Peng  Kao  Jiawei  Cheng  Fushan  Sun  Yiliu  Fu  Shihao  Ren  Lejia 《Geotechnical and Geological Engineering》2022,40(8):4057-4067

Geotechnical and Geological Engineering - The fracture vertical stretching distance and fracture morphologies have great impact on the stimulated reservoir volume and well production in layered...  相似文献   

Magnetotelluric studies in the Market Weighton area of eastern England   总被引：1，自引：0，他引：1  

D. Kao  D. Orr 《Geophysical Journal International》1982,70(2):323-337

Summary Magnetotelluric measurements at periods from 30 to 1000s were made at eight locations in the Market Weighton (MW) area, along an east—west profile across gravity and magnetic anomalies. Dimensional parameters were developed for assessing the structural dimensionality of the electrical conductivity of the Earth from the data. One-dimensional inversion modelling techniques were employed to interpret the data at each site, and four-layer models were obtained to explain the main structure of the crust in the area studied. If it is assumed that all strata are unmagnetized then the results show that there is a highly resistive layer in the crust, the thickness of the highly resistive layer ranges from 12 km in the east to 44 km in the west with a large change in the middle near the MW site. A structural boundary lying north—south near MW was also indicated by the principal directions of rotated apparent resistivities and transfer functions. Both electrical conductivity and magnetic permeability contrast in the ground were considered in an attempt to interpret the observed variations in apparent resistivity at different periods.  相似文献   

Control of BTEX Migration Using a Biologically Enhanced Permeable Barrier   总被引：2，自引：0，他引：2  

Robert C. Borden  Russell Todd Goin  Chih-Ming Kao 《Ground Water Monitoring & Remediation》1997,17(1):70-80

A permeable barrier system. consisting of a line of closely spaced wclls. was installed perpendicular to ground water flow to control the migration of a dissolved hydrocarhon plume. The wells were charged wiih concrete briquets that release oxygen and nitrate at a controlled rate. enhancing aerobic bio-degradation in the downgradient aquifer.
Laboratory batch reactor experiments were conducted to identify concrete mixtures that slowly released oxygcn over an extended time period. Concretes prepared with urea hydrogen peroxide were unsatisfactory, while concretes prepared with calcium peroxide and a proprietary formalation of magnesium peroxide (ORC®) gradually released oxygen at a steadily declining rate. The 21 percent MgO₂ conerete cylinders and briquets released oxygen at measurable rates for up to 300 days, while the 14 percent CaO₂ briquets were exhausted by 100 days.
A full-scale permeable barrier system using ORC was constructed at a gasoline-spill site. During the first 242 days of operation. total BTFX decreased from 17 to 3.4 mg/L. and dissolved oxygen increased from 0.4 to 1.8 mg/L. during transport through the barrier. Over time, BTEX treatment efficiencies declined. indicating the barrier system had becomc less effective in releasing oxygen and nutrients to the highly contaminated portion of the aquifer. Point dilution tests and sediment analyses performed at the conclusion of the project indicated that ihc aquifer in the vicinity of the remediation wells had been clogged by precipitation with iron minerals. This clogging is believed to result from high pH from the concrete and oxygen released by ihc ORC. Oxygen-releasing permeable barriers and other aerobic bioremediation processes should be used with caution in aquifers with high levels of dissolved iron.  相似文献   

Analyses of stomach contents and stable isotopes reveal food sources of estuarine detritivorous fish in tropical/subtropical Taiwan   总被引：1，自引：0，他引：1  

Hsing-Juh Lin  Wen-Yuan Kao  Ya-Ting Wang 《Estuarine, Coastal and Shelf Science》2007,73(3-4):527-537

Detritivorous fish generally refers to fish that primarily ingest unidentified organic detritus. We analyzed stomach contents in combination with stable isotopes to trace and compare the food sources of the large-scale mullet Liza macrolepis and other detritivorous fish species in subtropical mangrove creeks and a tropical lagoon in Taiwan. The volume of organic detritus always contributed >50% of the stomach content of L. macrolepis in the two habitats. However, consumed items were distinct between the two habitats and corresponded to the types in which they reside. The consumed items in the lagoon were more diverse than those observed in the mangroves. In the mangroves, the diet composition of L. macrolepis was primarily determined by season, not by body size. In the lagoon, there were no clear seasonal or size-dependent grouping patterns for the diet composition. There were significant seasonal and spatial variations in δ¹³C and δ¹⁵N values of potential food sources and L. macrolepis. However, neither δ¹³C nor δ¹⁵N values of L. macrolepis were correlated with fish body size. Joint analyses of stomach contents and stable isotopes indicated that benthic microalgae on sediments were the most important assimilated food in both seasons for the dominant detritivorous fish in the mangroves, whereas a greater reliance on microalgal and macroalgal periphyton on oyster-culture pens was observed in the lagoon. Mangrove and marsh plants and phytoplankton, which are mostly locally produced within each habitat, were of minor importance in the assimilated food.  相似文献   

Evidence for underthrusting beneath the Queen Charlotte Margin, British Columbia, from teleseismic receiver function analysis     

A. M. M. Bustin  R. D. Hyndman  H. Kao  J. F. Cassidy 《Geophysical Journal International》2007,171(3):1198-1211

The Queen Charlotte Fault zone is the transpressive boundary between the North America and Pacific Plates along the northwestern margin of British Columbia. Two models have been suggested for the accommodation of the ∼20 mm yr⁻¹ of convergence along the fault boundary: (1) underthrusting; (2) internal crustal deformation. Strong evidence supporting an underthrusting model is provided by a detailed teleseismic receiver function analysis that defines the underthrusting slab. Forward and inverse modelling techniques were applied to receiver function data calculated at two permanent and four temporary seismic stations within the Queen Charlotte Islands. The modelling reveals a ∼10 km thick low-velocity zone dipping eastward at 28° interpreted to be underthrusting oceanic crust. The oceanic crust is located beneath a thin (28 km) eastward thickening (10°) continental crust.  相似文献   

Hypocentre determination offshore of eastern Taiwan using the Maximum Intersection method   总被引：3，自引：0，他引：3  

Yvonne Font  Honn Kao  Serge Lallemand  Char-Shine Liu  Ling-Yun Chiao 《Geophysical Journal International》2004,158(2):655-675

  相似文献   

Turbulent diffusion in linear shear flow     

S. K. Kao  J. C. Doran 《Pure and Applied Geophysics》1976,114(3):357-363

Summary An analysis of the characteristics of the eddy diffusivity is made, and the equation for turbulent diffusion in a linear flow is derived. This diffusion equation is solved analytically.  相似文献