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21.
22.
Li Li Yang Hong Jiahu Wang Robert F. Adler Frederick S. Policelli Shahid Habib Daniel Irwn Tesfaye Korme Lawrence Okello 《Natural Hazards》2009,50(1):109-123
Many researchers seek to take advantage of the recently available and virtually uninterrupted supply of satellite-based rainfall
information as an alternative and supplement to the ground-based observations in order to implement a cost-effective flood
prediction in many under-gauged regions around the world. Recently, NASA Applied Science Program has partnered with USAID
and African-RCMRD to implement an operational water-hazard warning system, SERVIR-Africa. The ultimate goal of the project
is to build up disaster management capacity in East Africa by providing local governmental officials and international aid
organizations a practical decision-support tool in order to better assess emerging flood impacts and to quantify spatial extent
of flood risk, as well as to respond to such flood emergencies more expediently. The objective of this article is to evaluate
the applicability of integrating NASA’s standard satellite precipitation product with a flood prediction model for disaster
management in Nzoia, sub-basin of Lake Victoria, Africa. This research first evaluated the TMPA real-time rainfall data against
gauged rainfall data from the year 2002 through 2006. Then, the gridded Xinanjiang Model was calibrated to Nzoia basin for
period of 1985–2006. Benchmark streamflow simulations were produced with the calibrated hydrological model using the rain
gauge and observed streamflow data. Afterward, continuous discharge predictions forced by TMPA 3B42RT real-time data from
2002 through 2006 were simulated, and acceptable results were obtained in comparison with the benchmark performance according
to the designated statistic indices such as bias ratio (20%) and NSCE (0.67). Moreover, it is identified that the flood prediction
results were improved with systematically bias-corrected TMPA rainfall data with less bias (3.6%) and higher NSCE (0.71).
Although the results justify to suggest to us that TMPA real-time data can be acceptably used to drive hydrological models
for flood prediction purpose in Nzoia basin, continuous progress in space-borne rainfall estimation technology toward higher
accuracy and higher spatial resolution is highly appreciated. Finally, it is also highly recommended that to increase flood
forecasting lead time, more reliable and more accurate short- or medium-range quantitative precipitation forecasts is a must. 相似文献
23.
Habib Belayouni Angelida Di Staso Francesco Guerrera Manuel Martín Martín Crina Miclǎuş Francisco Serrano Mario Tramontana 《International Journal of Earth Sciences》2009,98(1):157-176
An integrated stratigraphic analysis has been made of the Tarcău Nappe (Moldavidian Domain, Eastern Romanian Carpathians),
coupled with a geochemical study of organic-rich beds. Two Main Sequence Boundaries (Early Oligocene and near to the Oligocene–Aquitanian
boundary, respectively) divide the sedimentary record into three depositional sequences. The sedimentation occurred in the
central area of a basin supplied by different and opposite sources. The high amount of siliciclastics at the beginning of
the Miocene marks the activation of the “foredeep stage”. The successions studied are younger than previously thought and
they more accurately date the deformation of the different Miocene phases affecting the Moldavidian Basin. The intervals with
black shales identified are related to two main separate anoxic episodes with an age not older than Late Rupelian and not
before Late Chattian. The most important organic-rich beds correspond to the Lower Menilites, Bituminous Marls and Lower Dysodilic
Shales Members (Interval 2). These constitute a good potential source rock for petroleum, with homogeneous Type II oil-prone organic matter, highly lipidic and thermally immature. The deposition of black shales has been interpreted as occurring
within a deep, periodically isolated and tectonically controlled basin. 相似文献
24.
Sajjad Hussain Saima Gul Sabir Khan Habib ur Rehman 《Arabian Journal of Geosciences》2013,6(11):4547-4556
In the present study, the retention capacity of carbonaceous material obtained from the diesel engine exhaust mufflers for Cr(VI) removal has been investigated. The physicochemical properties such as density, pH of aqueous slurry, pH at point of zero charge, ash content, moisture content, volatile matter, surface area, scanning electron microscopy and electron dispersive spectroscopy of the carbonaceous material were determined. The capacity of adsorbent for removal of Cr(VI) from aqueous solution was observed under different experimental condition like contact time, initial concentration of metal ions, pH and temperatures on the adsorption capacity of the adsorbent. Maximum adsorption of Cr(VI) ions was found at low pH. The adsorption process was found to follow second-order kinetics. The rate constant was evaluated at different temperatures along with other thermodynamic parameters like activation energy, Gibbs free energy change, enthalpy change and entropy change. Both Langmuir and Freundlich isotherms were used to describe the adsorption equilibrium of carbonaceous material at different temperatures. Langmuir isotherm shows better fit than Freundlich isotherm at given conditions. The result shows that low-cost carbonaceous material from diesel engine exhaust mufflers can be efficiently used for wastewater treatment containing Cr(VI) ions. 相似文献
25.
26.
Hajer Khemakhem Jannet Elloumi Mahmoud Moussa Lotfi Aleya Habib Ayadi 《Estuarine, Coastal and Shelf Science》2010
The distribution of phytoplankton abundance, biomass and species composition coupled with environmental factors and metazooplankton was studied relatively intensively and over a period of four consecutive years in five ponds featuring a gradient of increasing salinity from near to that of sea water to a nine-fold concentration from 2000 to 2003. The results indicate that the physical characteristics of the water (temperature and salinity) were quite similar over the years. Nutrients, which were concentrated in pond A1, decreased with increases in salt concentration. The composition of the phytoplankton community showed strong seasonality. Diatoms dominated in the first ponds A1, A16 and C2-1, followed by dinoflagellates. Chlorophyceae dominated the phytoplankton community in the hypersaline ponds M2 and TS. Cyanobacteriae were relatively abundant in ponds M2 and TS. The highest phytoplankton density and biomass were found in the ponds with the highest salinity due to the proliferation of Dunaliella salina (Chlorophyta: Volvocales). The inter-annual study of phytoplankton succession in the Sfax solar salterns showed slight differences among the years of study due to the stability of the environmental conditions. Phytoplankton communities were permanently primitive, stage 1 – structured as they failed to build complexity because of salt stress which operates for longer and above any other variables. This reduced frequency of disturbance to the existing course of regulation, allowed the community to “mature” from its “primitive” state, rather than experience frequent structural setbacks. 相似文献
27.
Active tectonic morphology and submarine deformation of the northern Gulf of Eilat/Aqaba from analyses of multibeam data 总被引:1,自引:0,他引:1
Gideon Tibor Tina M. Niemi Zvi Ben-Avraham Abdallah Al-Zoubi Ronnie A. Sade John K. Hall Gal Hartman Emad Akawi Abdelrahmem Abueladas Rami Al-Ruzouq 《Geo-Marine Letters》2010,30(6):561-573
A high-resolution marine geophysical study was conducted during October-November 2006 in the northern Gulf of Aqaba/Eilat,
providing the first multibeam imaging of the seafloor across the entire gulf head spanning both Israeli and Jordanian territorial
waters. Analyses of the seafloor morphology show that the gulf head can be subdivided into the Eilat and Aqaba subbasins separated
by the north-south-trending Ayla high. The Aqaba submarine basin appears starved of sediment supply, apparently causing erosion
and a landward retreat of the shelf edge. Along the eastern border of this subbasin, the shelf is largely absent and its margin
is influenced by the Aqaba Fault zone that forms a steep slope partially covered by sedimentary fan deltas from the adjacent
ephemeral drainages. The Eilat subbasin, west of the Ayla high, receives a large amount of sediment derived from the extensive
drainage basins of the Arava Valley (Wadi ’Arabah) and Yutim River to the north–northeast. These sediments and those entering
from canyons on the south-western border of this subbasin are transported to the deep basin by turbidity currents and gravity
slides, forming the Arava submarine fan. Large detached blocks and collapsed walls of submarine canyons and the western gulf
margin indicate that mass wasting may be triggered by seismic activity. Seafloor lineaments defined by slope gradient analyses
suggest that the Eilat Canyon and the boundaries of the Ayla high align along north- to northwest-striking fault systems—the
Evrona Fault zone to the west and the Ayla Fault zone to the east. The shelf–slope break that lies along the 100 m isobath
in the Eilat subbasin, and shallower (70–80 m isobaths) in the Aqaba subbasin, is offset by approx. 150 m along the eastern
edge of the Ayla high. This offset might be the result of horizontal and vertical movements along what we call the Ayla Fault
on the east side of the structure. Remnants of two marine terraces at 100 m and approx. 150 m water depths line the southwest
margin of the gulf. These terraces are truncated by faulting along their northern end. Fossil coral reefs, which have a similar
morphological appearance to the present-day, basin margin reefs, crop out along these deeper submarine terraces and along
the shelf–slope break. One fossil reef is exposed on the shelf across the Ayla high at about 60–63 m water depth but is either
covered or eroded in the adjacent subbasins. The offshore extension of the Evrona Fault offsets a fossil reef along the shelf
and extends south of the canyon to linear fractures on the deep basin floor. 相似文献
28.
Distribution of ciliates in relation to environmental factors along the coastline of the Gulf of Gabes, Tunisia 总被引:1,自引:0,他引:1
Nouha Kchaou Jannet Elloumi Zaher Drira Asma Hamza Habib Ayadi Abderrahmen Bouain Lotfi Aleya 《Estuarine, Coastal and Shelf Science》2009,83(4):414-424
We studied the seasonal distribution of the ciliate community coupled with environmental factors along the coast at three stations sampled (from March 2006 to February 2007) in the Gulf of Gabes (Tunisia, Eastern Mediterranean Sea). A total of 56 species belonging to 11 orders, were identified. Harbor of Gabes station was more diversified (45 species) than both Tabia (26 species) and Karboub (31 species) stations. The ciliate assemblage was numerically dominated by Spirotrichea in Tabia (82% of the total abundance), in the Harbor of Gabes (86% of the total abundance), whereas, in Karboub, Spirotrichea represented only 40% of the total abundance. The unexpected lower quantitative importance of Spirotrichea in Karboub station was apparently the result of the high salt concentration found in water samples throughout the study, probably originating from the saline area surrounding Karboub station, known as Sabkha. The distribution of species in the nearshore of the Gulf of Gabes seemed most likely influenced by the combined effects of temperature, salinity and hydrographic conditions. 相似文献
29.
Ayman F. Habib Ana Paula Kersting Ki-In Bang Ruifang Zhai Mohannad Al-Durgham 《The Photogrammetric Record》2009,24(126):171-195
Lidar (laser scanning) technology has been proven as a prominent technique for the acquisition of high-density and accurate topographic information. Because of systematic errors in the lidar measurements (drifts in the position and orientation information and biases in the mirror angles and ranges) and/or in the parameters relating the system components (mounting parameters), adjacent lidar strips may exhibit discrepancies. Although position and orientation drifts can have a more significant impact, these errors and their impact do not come as a surprise if the quality of the GPS/INS integration process is carefully examined. Therefore, the mounting errors are singled out in this work. The ideal solution for improving the compatibility of neighbouring strips in the presence of errors in the mounting parameters is the implementation of a rigorous calibration procedure. However, such a calibration requires the original observations, which may not be usually available. In this paper, a strip adjustment procedure to improve the compatibility between parallel lidar strips with moderate flight dynamics (for example, acquired by a fixed-wing aircraft) over an area with moderately varying elevation is proposed. The proposed method is similar to the photogrammetric block adjustment of independent models. Instead of point features, planar patches and linear features, which are represented by sets of non-conjugate points, are used for the strip adjustment. The feasibility and the performance of the proposed procedure together with its impact on subsequent activities are illustrated using experimental results from real data. 相似文献
30.
利用NOAA-AVHRR数据分析1982-2001年间中国植被的动态变化(英文) 总被引:1,自引:0,他引:1
The authors derived the normalized difference vegetation index (NDVI) from the NOAA/AVHRR Land dataset, at a spatial resolution of 8km and 15-day intervals, to investigate the vegetation variations in China during the period from 1982 to 2001. Then, GIS is used to examine the relationship between precipitation and the Normalized Difference Vegetation Index (NDVI) in China, and the value of NDVI is taken as a tool for drought monitoring. The results showed that in the study period, China’s vegetation cover h... 相似文献