Identification of the influencing factors on groundwater drought and depletion in north-western Bangladesh     

Syed?Md.?Touhidul?MustafaEmail authorView author&#;s OrcID profile  Khodayar?Abdollahi  Boud?Verbeiren  Marijke?Huysmans 《Hydrogeology Journal》2017,25(5):1357-1375

Groundwater drought is a specific type of hydrological drought that concerns groundwater bodies. It may have a significant adverse effect on the socio-economic, agricultural, and environmental conditions. Investigating the effect of different climatic and anthropogenic factors on groundwater drought provides essential information for sustainable planning and management of (ground) water resources. The aim of this study is to identify the influencing factors on groundwater drought in north-western Bangladesh, to understand the forcing mechanisms. A multi-step methodology is proposed to achieve this objective. The standardised precipitation index (SPI) and reconnaissance drought index (RDI) have been used to quantify the aggregated deficit between precipitation and the evaporative demand of the atmosphere, i.e. meteorological drought. The influence of land-cover patterns on the groundwater drought has been identified by calculating spatially distributed groundwater recharge as a function of land cover. Groundwater drought is defined by a threshold method. The results show that the evapotranspiration and rainfall deficits are determining meteorological drought, which shows a direct relation with groundwater recharge deficits. Land-cover change has a small effect on groundwater recharge but does not seem to be the main cause of groundwater-level decline (depletion) in the study area. The groundwater depth and groundwater-level deficit (drought) is continuously increasing with little correlation to meteorological drought or recharge anomalies. Overexploitation of groundwater for irrigation seems to be the main cause of groundwater-level decline in the study area. Efficient irrigation management is essential to reduce the growing pressure on groundwater resources and ensure sustainable water management.  相似文献   

Abundance and Ecology of Endemic Asterorotalia trispinosa from the Western Bay of Bengal: Implications for its Application as a Paleomonsoon Proxy     

Rajeev?SARASWAT  Manumalenki?MANASA  Thejasino?SUOKHRIE  Mohammad?Syed?SAALIM  Rajiv?NIGAM 《《地质学报》英文版》2017,91(6):2268-2282

A total of 97 surface sediment samples were collected from the continental shelf and slope of the western Bay of Bengal to assess the potential application of Asterorotalia trispinosa as a paleomonsoon proxy. The relative abundance of living as well as total (living and dead) A. trispinosa ranges from being absent to a maximum of ~31%. The highest abundance of A. trispinosa is close to the outfall region of the Ganga-Brahmaputra Rivers and decreases away from the river mouths. Contrary to that, A. trispinosa is rare in front of both the Cauvery and Pennar river outfall regions, in the central part of the western Bay of Bengal. The living A. trispinosa abundance is the lowest in between two major river systems, viz. Ganga-Brahmaputra-Mahanadi and Krishna-Godavari. The relative abundance of both the total and living A. trispinosa is strongly positively correlated with ambient seawater temperature, and negatively correlated with %Corg and salinity. Based on the spatial distribution, we conclude that A. trispinosa is stenohaline in nature, rather than euryhaline, and further that the increased relative abundance of A. trispinosa indicates warmer and only marginally hyposaline environment. Even though the ecological preference of A. trispinosa suggests it as a potential paleomonsoon proxy, the restricted distribution implies limited application.  相似文献   

Evolution of stress in Southern California for the past 200 years from coseismic, postseismic and interseismic stress changes   总被引：6，自引：0，他引：6  

Andrew M. Freed  Syed Tabrez Ali  Roland Bürgmann 《Geophysical Journal International》2007,169(3):1164-1179

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Study on mechanochemical effect of silica for short grinding period     

Samayamutthirian Palaniandy  Khairun Azizi Mohd AzizliHashim Hussin  Syed Fuad Saiyid Hashim 《International Journal of Mineral Processing》2007

Silica was ground in an oscillating mill at various grinding period to study the mechanochemical effect in fine grinding process. The ground particles exhibited massive size reduction where the volume moment diameter of 5.56 μm was reached within 600 s. Aggregation of fine particles was very pronounced when it was ground for 600 s due to high surface energy. Aggregation of fine particles caused the ground particles to exhibit poly-modal particle size distribution. Line broadening and reduction of diffractogram peak intensity were observed. Amorphization rate up to 16.9% was exhibited by the particle ground for 600 s. Preferential breakage of plane was observed where (101) and (111) was easily distorted compared to (110) and (200). Rapid reduction of crystallite size was observed at early stage of grinding until it reached a plateau at 5 nm at 600 s whilst the change in lattice strain was 0.5%.  相似文献   

Weather yield model for the semi tropical region (Pakistan)     

Syed Faizan Haider  K. H. Asif  Amjad Hussain Gilani 《大气科学进展》1992,9(3):367-372

Weather models are essential tools for checking of the effect of the weather elements in terms of their effect on the production of the crop. This research is an attempt to see the effect of only two variables i.e., temperature and rainfall for the division Faisalabad (semitropical region of Pakistan).The model fitted is of the linear form:the values of a,b, c have been found. The expected yield has been calculated by using the aridity indices (X1 and X2 ) and the result in the form of coefficient of determination R2 has been found equal to 0.166. The significance of the regression coefficient has been tested, which shows that the contribution to the yield from aridity index at germination and that at ripening is significant.The wheat yields are the results of a wide variety of variables, most of which show varying degree of relationship with one another, some positive and some negative in terms of output. These variables may be technology, fertilizers, pesticides, epidemics, kinds of seeds used, market price of crop and the area under cultivation etc, which can be the source of variation in the wheat yield. Since rainfall during germination and temperature at the ripening periods are the necessary factors for the yield of wheat, for this purpose these parameters have been studied in order to their contribution.  相似文献   

Engineering properties of sabkha soils in the benghazi plain and construction problems     

Iqbal H. Khan  Syed I. Hasnain 《Engineering Geology》1981,17(3):175-183

This paper describes the geological, geotechnical and chemical properties of some Sabkha (lagoonal) soils in the Benghazi plain. Several buildings constructed on such soils show tilting and cracks. The cause of this trouble has been traced to the special characteristics of Sabkha soils. It is suggested that improved mix design and dense concrete should be used so as to make concrete in the foundation impermeable.  相似文献   

Cluster analysis of marine sediments and waste deposits in New York bight     

Syed A. Ali  M. Grant Gross  John R. L. Kishpaugh 《Environmental Geology》1975,1(3):143-148

Cluster analysis of some chemical characteristics of marine sediments and associated waste deposits in the New York Bight reveals the existence of four cluster facies. Cluster facies I is the sediment containing dredged wastes from New York Harbor. Cluster facies II is the widespread sand and gravel deposit of the continental shelf. Cluster facies III is the finergrained material in the Hudson Channel and the material accumulated in the sewage sludge disposal area. Cluster facies IV is not easily identified; it may correspond to some relict sedimentary feature in the area. Editor's Note: Ali is now with the Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543; Gross is now with Chesapeake Bay Institute. The Johns Hopkins University, Baltimore, Maryland 21218.  相似文献   

Photo-characters of vindhyan sedimentaries in parts of chittorgarh district,Rajashtan     

Iqbaluddin Ali  Syed Ahmad Ali 《Journal of the Indian Society of Remote Sensing》1984,12(2):27-30

Variable tonal densities, erosional resistance, drainage pattern, density and channel profile together with landuse pattern, vegetation pattern and structural expressions have been used as recognition elements for the lithological mapping of the Vindhyan Basin, Rajas than. Local relationship of superposition, spatial continuity and ground truth have been used for establishing lithostratigraphy in the Parsoli-Bichor syncline. The recognition elements established may serve as guide for rapid lithological mapping through extrapolation techniques.  相似文献   

THE THEME OF "RELEVANCE" IN THIRD WORLD HUMAN SCIENCES     

Syed Farid Alatas 《Singapore journal of tropical geography》1996,16(2):123-140

The fact that the humanities and social sciences in developing societies generally originated in the West has raised the issue of the relevance of these arts and sciences to the needs and problems of Third World societies. This questioning of relevance has led, in turn, to the call for the indigenisation of knowledge in developing societies. While there has been a great deal of discussion on indigenisation, there has been little practice of indigenised humanities and social science. As a result, there are few examples of what indigenous knowledge constitutes from theoretical, methodological and empirical points of view. This paper is directed towards arriving at some conception of what indigenised knowledge is, the various forms that it takes, and its rationale.  相似文献   

Groundwater control for construction purposes: a case study from Kuwait   总被引：1，自引：0，他引：1  

Fathi M. Shaqour  Syed E. Hasan 《Environmental Geology》2008,53(8):1603-1612

One of the major rehabilitation projects in Kuwait during the 1990s was improvement of the wastewater treatment plant at Jahra, a town 30 km north of Kuwait City. The project incorporates construction of a pumping station to collect the sewage via a network of sewer lines throughout the city. Groundwater occurs 4 m below the ground surface and construction specifications required lowering the groundwater table by 16 m to the foundation grade, 20 m below the ground surface. Open excavation with four stage well point system of dewatering was selected to ensure dry foundation conditions; but the system failed to lower the groundwater table down to the desired depth. Review of site investigation records and recalculation of field hydraulic conductivity resulted in design changes, augmenting the well point system with a number of deep wells and sumps to lower the water table down to the foundation grade. The paper discusses subsurface conditions and presents an analysis of the cause of failure of the well point system. The actual hydraulic conductivity proved to be several folds higher than the calculated one that was determined using Hazen’s formula. It was found that use of Hazen’s formula led to serious underestimation of field hydraulic conductivity. It is advised not to use such formulas without thorough investigation and proper interpretation of borehole data.  相似文献