Correlation between nitrate contamination and ground water pollution potential   总被引：1，自引：0，他引：1  

Chowdhury SH  Kehew AE  Passero RN 《Ground water》2003,41(6):735-745

AQUIPRO, a PC-based method, was used to assess aquifer vulnerability using digital water well logs. The AQUIPRO model is a parameter/factor weighting system for rating the pollution potential of an aquifer. This method uses the well depth, as well as the clay and partial clay thickness in a well, to generate pollution potential scores. In this model, aquifer protection increases as the AQUIPRO vulnerability scores increase and ground water pollution potential decreases. Computerized water well records of 2435 domestic wells with partial chemistry data were used to determine the ground water pollution potential of Kalamazoo County, Michigan. Theoretically, low AQUIPRO pollution potential scores should have more frequent occurrences of ground water contamination events than areas with high AQUIPRO scores with similar land-use, well construction, and well densities. The relative AQUIPRO scores were compared with the frequency of occurrences of nitrate-N in ground water wells. The average nitrate-N concentrations within each relative AQUIPRO vulnerability scores category were also compared. The results indicate that domestic wells containing 5 mg/L or more nitrate-N showed a positive correlation between the frequency of occurrences of nitrate-N and relative decrease of AQUIPRO (r2 = 0.99) vulnerability scores. In other words, as the ground water pollution potential increases, the occurrence frequency of nitrate-N also increases. Furthermore, the results show that as the relative AQUIPRO (r2 = 0.96) vulnerability scores decrease, the mean nitrate-N concentrations also increase.  相似文献   

TOXICITY OF TWO HERBICIDES 2,4 -D DIMETHYLAMINE AND BENSULFURON METHYL TO RICE FIELD CHIRONOMUS KIIENSIS (TOKUNAGA) ( DIPTERA: CHIRONOMIDAE)     

Al-Shami S A　Che Salmah M R　Siti Azizah M N　Abu Hassan A　Azmi M 《湿地科学》2006,4(4):241-246

1 INTRODUCTIONRice field is a unique man -made wetland envi-ronment where many varieties of aquatic insects oc-curred ( Ali, Ahmad, 1988; Yamazaki,et al,2001a; Che Salmah, Abu Hassan, 2002). Duringrice cultivation in Malaysia, herbicides are used in-tensi…  相似文献   

Monitoring and modelling tropical deforestation: Introduction to the Special Issue     

Douglas O. Fuller  Rinku Roy Chowdhury 《Singapore journal of tropical geography》2006,27(1):1-3

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Estimation of frequency dependent coda wave attenuation structure at the vicinity of Cairo Metropolitan Area   总被引：1，自引：0，他引：1  

Salah El-Hadidy  M. E. Mohamed Adel  Ahmed Deif  Ahmed Sayed Abu El-Ata  S. R. Moustafa Sayed 《Acta Geophysica》2006,54(2):177-186

Estimation of seismic wave attenuation in the shallow crust in terms of coda wave Q structure previously investigated in the vicinity of Cairo Metropolitan Area was improved using seismograms of local earthquakes recorded by the Egyptian National Seismic Network. The seismic wave attenuation was measured from the time decay of coda wave amplitudes on narrow bandpass filtered seismograms based on the single scattering theory. The frequency bands of interest are from 1.5 to 18 Hz. In general, the values obtained for various events recorded at El-Fayoum and Wadi Hagul stations are very similar for all frequency bands. A regional attenuation law Q _c = 85.66 f ^0.79 was obtained.  相似文献   

An index to assess agricultural drought in India     

A. Chowdhury  P. G. Gore 《Theoretical and Applied Climatology》1989,40(3):103-109

Summary Crop drought or moisture stress is a function of the difference between actual evapotranspiration and evapotranspiration requirements of the crop under given atmospheric conditions.In the present work the climatic water balance approach is utilized to develop a crop moisture index for the kharif crop season over India.The difference between actual and climatologically derived evapotranspiration have been accumulated for different consecutive weeks of the crop season and made comparable in time and space through suitable weights. The lowest weighted deficit values have then been used for successive weeks to evolve the Crop Moisture Index. This index enables detection of degree of moisture stress experienced by the crop and can be used in drought monitoring.

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Zusammenfassung Dürre oder Feuchtestreß ist eine Funktion der Differenz zwischen tatsächlicher Verdunstung und dem Verdunstungsbedarf für bestimmte Kulturpflanzen unter gegebenen atmosphärischen Bedingungen. In vorliegender Studie wird die klimatische Wasserbilanz verwendet, um einen Feuchtigkeitsindex für die Kharif-Anbauzeit in Indien zu erstellen.Die Differenz zwischen aktueller und klimatologisch errechneter Verdunstung wurde für einige aufeinanderfolgende Wochen der Erntezeit aufsummiert und durch geeignete Gewichtungen in Zeit und Raum vergleichbar gemacht. Die am wenigsten veränderten Defizitwerte wurden dann für aufeinanderfolgende Wochen zur Errechnung eines Feuchtigkeitsindex herangezogen. Dieser Index ermöglicht die Quantifizierung des für die Pflanzen relevanten Feuchtestresses und kann für die Aufzeichnung von Dürren verwendet werden.

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With 2 Figures  相似文献   

Aspects of the Vajont slide     

Robin N. Chowdhury 《Engineering Geology》1987,24(1-4):533-540

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Change detection study of islands in Hooghly estuary using multidate satellite images     

K. Vinod Kumar  Arup SPaltt  A. K. Chakrabortt  S. K. Bhan  B. Chowdhury  T. Sanyal 《Journal of the Indian Society of Remote Sensing》1994,22(1):1-7

River estuarine environment constitutes a highly dynamic fluvio-morphological setting where processes of accretion and deposition are active. Hooghly estuary, being one of the largest of estuaries in the east coast of India, needs constant monitoring. Multidate satellite images of IRS-1A L1SS-I and Landsat MSS for 1975–1991 period are studied to detect long term morphological changes in this estuary. The study reveals that the estuarine islands like Sagar, Ghorarmara and Suparbhanga are eroding whereas Lohachara islands has completely eroded off Nayachara island near Haldia due to its shape and size bifurcates the river into two channels. The island as revealed from Satellite images is in accretional phase where the total surface area has increased. The study, therefore, indicates that constant monitoring of spatial and temporal changes in this type of environment would help to understand physical processes.  相似文献   

The El Niño-Southern Oscillation (ENSO) and seasonal flooding – Bangladesh     

M. R. Chowdhury 《Theoretical and Applied Climatology》2003,76(1-2):105-124

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Prediction of heavy rainfall events over Rangamati,Bangladesh using high-resolution MM5 model     

M. N. Ahasan  M. A. Mannan Chowdhury  D. A. Quadir 《Meteorology and Atmospheric Physics》2015,127(2):183-190

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Simulation of vortex-induced vibrations of a cylinder using ANSYS CFX   总被引：1，自引：0，他引：1  

Abu Bakar Izhar  Arshad Hussain Qureshi  Shahab Khushnood 《中国海洋工程》2014,28(4):541-556

In this paper, vortex-induced vibrations of a cylinder are simulated by use of ANSYS CFX simulation code. The cylinder is treated as a rigid body and transverse displacements are obtained by use of a one degree of freedom spring damper system. 2-D as well as 3-D analysis is performed using air as the fluid. Reynolds number is varied from 40 to 16000 approx., covering the laminar and turbulent regimes of flow. The experimental results of （Khalak and Williamson, 1997） and other researchers are used for validation purposes. The results obtained are comparable.  相似文献