Rapid assessment of community needs and fisheries status in tsunami-affected communities in Aceh Province,Indonesia     

Len R. Garces  Michael D. Pido  Robert S. Pomeroy  Sonny Koeshendrajana  Budi Iskandar Prisantoso  Nurul Ahmad Fatan  Dedi Adhuri  T. Raiful  Syamsul Rizal  Alexander Tewfik  Madan Dey 《Ocean & Coastal Management》2010,53(2):69-79

This paper describes the application of the methodology called Rapid Appraisal of Fisheries Management System (RAFMS) to assess quickly the situation in tsunami-affected coastal fisheries in Aceh Province, Indonesia. As a diagnostic tool, the RAFMS is introduced in terms of its conceptual framework and procedures. The RAFMS was used to appraise the status of the fisheries sector in selected 15 villages. Information generated concerning level of fishing effort, marketing patterns and community perspectives on livelihood options are used as three illustrative examples. The paper also provides some insights in applying the RAFMS methodology in the context of disasters and in the broader context of tropical fisheries management.  相似文献   

Arsenic contamination of ground and pond water and water purification system using pond water in Bangladesh   总被引：1，自引：0，他引：1  

H. Yokota  K. Tanabe  M. Sezaki  Y. Akiyoshi  T. Miyata  K. Kawahara  S. Tsushima  H. Hironaka  H. Takafuji  M. Rahman  Sk. A. Ahmad  M. H. S. U. Sayed  M. H. Faruquee 《Engineering Geology》2001,60(1-4):323-331

This paper, firstly, shows the distribution of arsenic-contaminated groundwater in Samta village. This village, which is in Jessore district in Bangladesh, was chosen as a model village for investigating the mechanism of groundwater contamination. 90% of the tube wells in this village had arsenic concentrations above the Bangladesh standard of 0.05 mg/l. Tube wells with arsenic concentrations of over 0.50 mg/l were distributed in the southern part of the village with a belt-like shape from east to west. Secondly, groundwater distribution is discussed with respect to its flow and the high arsenic zone (As≥0.50 mg/l) agrees well with the drifting zone of the groundwater. Furthermore, arsenic-free water supply systems suitable for a small area in the village have been developed. A pond sand filter (PSF) system which purifies pond water is discussed in this paper. Prior to the construction of the PSF, the water quality in ponds was examined for arsenic levels. The inflow of drainage from the tube wells was found to be the major cause of arsenic contamination of pond water. The PSF installed in Samta is working very well and produces a good quality of treated water.  相似文献   

Optimum Spacing Of Extraction Wells     

W. Ahmad 《Hydrogeology Journal》1995,3(3):64-74

An approach to selecting the optimum spacing of extraction wells for both groundwater production and groundwater cleanup is presented. Optimum well spacing is dependent upon 1) whether the system consits of an odd or even number of wells, 2) total number of wells, 3) aquifer thickness (B), 4) regional groundwater velocity (U), and 5) pumping rate of an extraction well (Q). Although an exact optimum well spacing cannot be determined for a system that consists of 30 or more wells (due to a lack of convergence for finding the roots of the stagnation-point equation), the optimum well-spacing factor of 0.4765 x Q/BU ensures minimum loss of groundwater recovery between the wells for a system that consists of 30 to 200 wells. Optimum well spacing and the points on the capture-zone curves are presented. Regression equations were developed for estimating capture-zone curves. Specific capture-zone curves can be constructed for any number of wells with knowledge of the parameters, Q/BU. This approach provides a method to design a new group of extraction wells and modify existing but deficient and under-designed systems, where more extraction wells are required. Using this scheme for such a modification, it is recommended that the number of wells be increased in pairs. The resulting arrangement ensures minimum loss of groundwater recovery between the wells. RÉSUMÉ: Une approche est proposée afin d'optimiser l'espacement de puits de pompage aussi bien pour capter l'eau souterraine que pour dépolluer une nappe. L'espacement optimal de puits dépend des conditions suivantes: 1) dispositif constitué d'un nombre pair ou impair de puits, 2) nombre total de puits, 3) épaisseur de l'aquifère (B), 4) vitesse de l'écoulement souterrain régional (U), et 5) le débit d'exploitation d'un puits (Q). Bien que l'espacement optimal exact ne puisse pas être trouvé pour un dispositif de 30 puits ou plus, du fait de l'impossibilité de faire converger le calcul, le facteur d'espacement optimal de 0.4765 x Q/BU garantit une perte minimale de la remontée de la nappe entre les puits, pour un dispositif constitué de 30 à 200 puits. L'espacement optimal et les points sur les courbes des zones de captage sont fournies. Des équations de régression sont établies dans le but d'estimer les courbes dans les zones de captage. Des courbes spécifiques des zones de captage peuvent être construites pour n'importe quel nombre de puits quand on connait le paramètre Q/BU. Cette approche fournit une méthode pour déterminer un nouveau groupe de puits de pompage et pour modifier un dispositif existant. Dans le cas d'une modification, il est recommandé d'augmenter le nombre de puits par paires. L'arrangement résultant garantit une perte minimale de la remontée de la nappe entre les puits. RESUMEN: Se presenta una metodología para la obtención de la separación óptima entre pozos, válida tanto para el caso de extracción como para el de limpieza de aguas subterráneas. El espaciado óptimo entre pozos depende de 1) si el sistema consiste en un número par o impar de pozos, 2) el número total de pozos, 3) el espesor saturado (B), 4) la velocidad de flujo regional (U), y 5) el caudal de bombeo de un pozo de extracción (Q). Aunque un valor óptimo de espaciado no se puede obtener de modo exacto para un sistema con un número de pozos superior a 30 (por la falta de convergencia al buscar las raíces de la ecuación que calcula los puntos de estagnación), un factor de espaciamiento de 0.4765 x Q/BU garantiza unas pérdidas mínimas de extracción para un sistema formado por 30 a 200 pozos. Se presenta el espaciado óptimo, así como las curvas de las zonas de captura, estas últimas estimadas mediante ecuaciones de regresión. Se pueden construir curvas de zonas de captura específicas para un número de pozos cualquiera, supuesto conocido el valor Q/BU. Esta metodología permite el diseño de nuevos grupos de extracción o la modificación de los ya existentes, en el caso que se consideren deficientes e infradimensionados. Al utilizar este esquema, se recomienda aumentar el número de pozos en un número par. La disposición final garantiza una pérdida mínima en las extacciones entre pozos.  相似文献   

Effects of land use and climate variability on the main stream of the Songhua River Basin,Northeast China     

Muhammad Abrar Faiz  Faisal Baig  Ahmad Niaz  Tianxiao Li 《水文科学杂志》2020,65(10):1752-1765

ABSTRACT

In this study, three representative concentration pathways (RCPs) and 15 general circulation models of the Coupled Model Intercomparison Project Phase 5 were used to assess the behaviour of precipitation (P) and surface air temperature (SAT) over part of the Songhua River Basin. The Water Evaluation and Planning (WEAP) model linked with SAT and P was used for monthly simulation of streamflow to assess the influence of land use/land cover and climate change on the streamflow. The results suggest that, under RCP2.6, RCP4.5 and RCP8.5, the SAT over the study area may increase in the 21st century by 1.12, 2.44 and 5.82°C, respectively. Moreover, by the middle of the 21st century, streamflow in the basin may have decreased by 19%. The decrease in streamflow may be due to changed land use conditions and water withdrawal, having critical implications for management and future planning of water resources in the basin.  相似文献   

Public food distribution systems in Indian cities     

Ahmad Aijazuddin  Singh Anjani K. 《GeoJournal》1980,4(1):27-47

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The fan faults of peninsular India and the origin of the Himalayas     

F. Ahmad  Z.S. Ahmad   《Tectonophysics》1980,64(1-2)

Mesozoic, Tertiary, Quaternary and Holocene faults, from the Indian subcontinent outside the Himalayan belt, that can be dated with confidence, are briefly described and it is pointed out that, with the exception of the Kirthar and perhaps the Sulaiman shear zones, all are normal and some of them are active.Plotted on a map all these faults seem to converge like a fan, to a point in the Arabian Sea. Also there seems to be a distinct and progressive younging of the faults in the anticlockwise sense. These facts appear difficult to explain, but may prove to be of value in any geotectonic study of the region.If the late and post-Mesozoic faults of the Peninsula are normal and some are even active, the Peninsula must be under tension. Earlier it appeared that a oroclinal rotation of the sub-continent was adequate to explain the phenomenon, for the faulting could have been largely preceded the collision with the northern landmass. However, the discovery of Quaternary-Holocene faults throws doubts on this supposition for this subcontinent has been obviously under tension since at least the Mesozoic. Some other explanation may, therefore, have to be sought for these phenomena.  相似文献   

Carbon isotope composition of graphite and carbonate minerals from 3.8-AE metamorphosed sediments,Isukasia, Greenland     

E.C. Perry  S.N. Ahmad 《Earth and Planetary Science Letters》1977,36(2):280-284

Graphite comprises about 2% of some of the 3.8-AE metamorphosed sedimentary rocks of Isukasia, west Greenland. δ¹³C_PDB of carbon in this graphite ranges from ?16.0 to ?9.3‰. For those samples that contain both graphite and siderite, Δ_{carbonate-graphite} is about 6; this fractionation is consistent with an inorganic equilibrium between siderite and graphite at roughly 400–500°C. It is likely that graphite found in these rocks formed by the reaction: 6FeCO₃ = 2Fe₃O₄ + 5CO₂ +C in which case it is of little help in determining whether or not organisms were active 3.8 AE ago. The presence of quartz-magnetite-cummingtonite-iron formation in the Isukasia metasedimentary sequence may, ultimately, be one of the most powerful environmental indicators remaining in these rocks.  相似文献   

The geochemical distribution and source of copper in the metalliferous mining region of Southwest England     

S. N. Ahmad 《Mineralium Deposita》1977,12(1):1-21

In order to test a hypothesis on the origin of copper in the Cornwall district, 270 samples of mafic rocks, 88 samples of sedimentary rocks and 78 samples of granitic rocks have been analysed for their copper contents. Among the mafic rocks, the intrusive microgabbro has a higher mean copper content (59±32 PPM) than the spilitic pillow lavas (43±27 PPM). The abundance of copper in the sedimentary rocks appears to be related to their lithological characters. The average copper content of the grey slates with carbonaceous material (47±16 PPM) is higher than that for the noncarbonaceous grey slates (29±20 PPM) The distribution of copper in the granitic rocks shows a marked relationship with the degree of mineralisation in the region. The average copper content of the granitic rocks from the intensely mineralized region is 73±18 PPM while the granitic rocks from the less mineralized region contain an average of 21±9 PPM copper. Further, it appears that there has been a general enrichment of copper from early granitic stage to the late pegmatites. These geochemical features can be of potential use in selecting intrusive bodies for detailed exploration. The high copper content in the country rock and in the mineralized intrusion plus a likelihood of assimilation of crust in forming granitic magmas suggest that the copper deposited as hydrothermal lodes may have been derived from the country rocks of the region.The work was completed at the Department of Geology, University of Birmingham, Birmingham 15, England.  相似文献   

Landscape evolution in The V1ndhyan Basin of Rajasthan     

Iqbaluddin  S. Ahmad Ali 《Journal of the Indian Society of Remote Sensing》1983,11(1):15-22

The basic geomorphic units in Parsoli surface of the Vindhyan Basin of Rajasthan have been photo-geomorphologically mapped. The paper presents morphology and controls of landscape genesis in structurally deformed cratonic regime.  相似文献   

CONCENTRATIONS OF Cd, Cu AND Zn IN SEDIMENTS COLLECTED FROM URBAN LAKES AT KELANA JAYA, PENINSULAR MALAYSIA     

Ahmad Ismail　Chee Kong YAP　Fong Fei Chan 《湿地科学》2004,2(4):248-258