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61.
Faisal K. Zaidi 《Journal of the Geological Society of India》2011,77(2):160-166
Drainage basin morphometry is a quantitative way of describing the characteristics of the surface form of a drainage basin
and provides important information about the region’s topography and underlying geological structures. It plays an important
role in hydrogeological investigations for delineating zones of adequate groundwater potential and selecting sites for construction
of artificial recharge structures. 相似文献
62.
Saravanan Mariappan Masashi Kamon Faisal Haji Ali Takeshi Katsumi Tomoyuki Akai Toru Inui Masaki Nishimura 《Geotechnical and Geological Engineering》2011,29(5):881-898
This paper addresses the study conducted on the performance of landfill liner interface parameters. Interface shear strength
parameters for various combinations of 9 different lining materials were studied and presented in this paper. This comprehensive
testing program covers the interfaces between: (1) soil and compacted clay liner (CCL), (2) geomembrane (HDPEs or PVC) and
soil, (3) geosynthetic clay liner (GCL)/CCL and soil, (4) geomembrane and geotextile, (5) geotextile and soil, (6) geotextile
and GCL/CCL, and (7) geomembrane and GCL/CCL. The experiments were conducted for both at dry or optimum moisture condition
and at saturated or wet condition. The interface performance under both conditions were compared to access the material performances.
Tabulated summaries of interface test data under dry or optimum moisture condition (OMO) and saturated or wet condition are
presented in the paper. 相似文献
63.
Major accidents are low-frequency, high-consequence accidents which are not well supported by conventional statistical methods due to the scarcity of directly relevant data. Modeling and decomposition techniques such as event tree have been proved as robust alternatives as they facilitate incorporation of partially relevant near accident data–accident precursor data—in probability estimation and risk analysis of major accidents. In this study, we developed a methodology based on event tree and hierarchical Bayesian analysis to establish informative distributions for offshore blowouts using data of near accidents, such as kicks, leaks, and failure of blowout preventers collected from a variety of offshore drilling rigs. These informative distributions can be used as predictive tools to estimate relevant failure probabilities in the future. Further, having a set of near accident data of a drilling rig of interest, the informative distributions can be updated to render case-specific posterior distributions which are of great importance in quantitative risk analysis. To cope with uncertainties, we implemented the methodology in a Markov Chain Monte Carlo framework and applied it to risk assessment of offshore blowouts in the Gulf of Mexico. 相似文献
64.
Radar estimates of rainfall are being increasingly applied to flood forecasting applications. Errors are inherent both in the process of estimating rainfall from radar and in the modelling of the rainfall–runoff transformation. The study aims at building a framework for the assessment of uncertainty that is consistent with the limitations of the model and data available and that allows a direct quantitative comparison between model predictions obtained by using radar and raingauge rainfall inputs. The study uses radar data from a mountainous region in northern Italy where complex topography amplifies radar errors due to radar beam occlusion and variability of precipitation with height. These errors, together with other error sources, are adjusted by applying a radar rainfall estimation algorithm. Radar rainfall estimates, adjusted and not, are used as an input to TOPMODEL for flood simulation over the Posina catchment (116 km2). Hydrological model parameter uncertainty is explicitly accounted for by use of the GLUE (Generalized Likelihood Uncertainty Estimation). Statistics are proposed to evaluate both the wideness of the uncertainty limits and the percentage of observations which fall within the uncertainty bounds. Results show the critical importance of proper adjustment of radar estimates and the use of radar estimates as close to ground as possible. Uncertainties affecting runoff predictions from adjusted radar data are close to those obtained by using a dense raingauge network, at least for the lowest radar observations available. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
65.
Ali Zulfiqar Hussain Ijaz Faisal Muhammad Grzegorczyk Marco Andreas Almanjahie Ibrahim M. Nazeer Amna Ahmad Ishfaq 《Theoretical and Applied Climatology》2020,140(1):25-36
Theoretical and Applied Climatology - Drought is a complex natural hazard that has been recurrently occurred in many regions across the globe. Therefore, precise drought characterization and its... 相似文献
66.
Abdolhossein Khalilnejad Faisal Hj. Ali Normaniza Osman 《Geotechnical and Geological Engineering》2012,30(2):277-288
Land sliding is a geotechnical event that includes a wide range of ground movements such as rockfalls, deep failure of slopes
and shallow debris flows, and it can cause various problems in varied civil fields such as roads and dams. Since most conventional
methods are neither inexpensive nor applicable everywhere, attention has nowadays been drawn to soil bioengineering using
vegetation as the environment-friendly method for slope stabilization. Soil bioengineering or using vegetation in civil engineering
design is mostly applicable to shallow slope stabilization projects characterized by unstable slopes with surface movement.
Vegetation has both a silent effect on soil improvement to predict the landslide and a mechanical role to increase shear and
pulling-out stress on the soil. During the last decade, many researches have been carried out to clarify the effect of vegetation
on slope stability, but many questions still remain to be answered. 相似文献
67.
1 Introduction Theuseofnaturalresources ,includingthosebeingofseeminglymarginalvalue ,isanimportanthumanactivitydesignedtoincreasefoodproductionandin come .Inagriculture ,soilsmaybetoosalinetosup portprofitablecrophusbandry ,yetsuchsoilmaybeusedalternat… 相似文献
68.
Collembola diversity in changing agricultural landscapes of the Thar Desert: A case study in Sriganganagar district of Rajasthan, India 总被引:1,自引:0,他引:1
Seven species of Collembola were recorded from the Thar Desert in India for the first time. Their existence and establishment has been attributed to the change in land use pattern of Sriganganagar district due to the development of canal irrigation. Sampling was done at two distant localities, in which one has been under irrigated agricultural activities since 60–70 years, while at the second locality, such activities began 20 years back. Two species, Xenylla obscura and Isotomodes dagamae, dominated the collembolan communities at all sites. The samples from first locality were rich both in number of individuals as well as species. The sites were hierarchically clustered into a dendrogram to present an analytical picture of community development of collembolan species against the time-scale of succession. Attention was sought to study the insect fauna and their activities in relation to the ongoing greening the desert program. 相似文献
69.
The disastrous flood of 1998 was a result of excessiverainfall all over the catchment areas of the major rivers of Bangladesh. Dhaka City, which is surroundedby rivers on all sides, was seriously affected despite the completion of Phase I of the Dhaka IntegratedFlood Protection Project (DIFPP). Water entered into the protected part of the city throughhydraulic leakage such as buried sewerage pipes, breached and incomplete floodwalls, ungated culverts andinoperative regulators. The drainage network and retention ponds of the city were found to be in poorconditions and capacities of the pumping stations were found inadequate. There was a serious lack of coordinationbetween the agencies responsible for flood protection and drainage of the city. These issues must beaddressed to achieve long-term flood mitigation. In addition, feedback from both the experts andgeneral public indicated that completion of Phase II of DIFPP was essential to bring the eastern part ofthe city under flood protection. Other structural measures suggested in this paper include installing andmaintaining adequate drainage and pumping capacity and timely operation of regulators. This studyalso suggests a set of non-structural measures for flood mitigation that include protectingthe retention ponds, raising public awareness on maintaining the city drains, introducing landzoning and flood proofing in the eastern part of Dhaka, and stream lining institutional bottlenecks. 相似文献
70.
Optimizing a piezometric network in the estimation of the groundwater budget: a case study from a crystalline-rock watershed in southern India 总被引:1,自引:0,他引:1
Faisal K. Zaidi Shakeel Ahmed Benoit Dewandel Jean-Christophe Maréchal 《Hydrogeology Journal》2007,15(6):1131-1145
An estimate of the groundwater budget at the catchment scale is extremely important for the sustainable management of available water resources. Water resources are generally subjected to over-exploitation for agricultural and domestic purposes in agrarian economies like India. The double water-table fluctuation method is a reliable method for calculating the water budget in semi-arid crystalline rock areas. Extensive measurements of water levels from a dense network before and after the monsoon rainfall were made in a 53 km2 watershed in southern India and various components of the water balance were then calculated. Later, water level data underwent geostatistical analyses to determine the priority and/or redundancy of each measurement point using a cross-validation method. An optimal network evolved from these analyses. The network was then used in re-calculation of the water-balance components. It was established that such an optimized network provides far fewer measurement points without considerably changing the conclusions regarding groundwater budget. This exercise is helpful in reducing the time and expenditure involved in exhaustive piezometric surveys and also in determining the water budget for large watersheds (watersheds greater than 50 km2). 相似文献