Modelling undrained behaviour of sand with fines and fabric anisotropy

Acta Geotechnica - Fabric anisotropy and fines content (fc) in sands modify significantly their mechanical behaviour, particularly as related to static liquefaction under undrained conditions. The...     

Observed Trends in Extreme Temperature over the Klang Valley,Malaysia

This study investigates the recent extreme temperature trends across 19 stations in the Klang Valley, Malaysia, over the period 2006-16. Fourteen extreme index trends were analyzed using the Mann-Kendall non-parametric test, with Sen’s slope as a magnitude estimator. Generally, the annual daily mean temperature, daily mean maximum temperature, and daily mean minimum temperature in the Klang Valley increased significantly, by 0.07°C yr~(-1), 0.07°C yr~(-1)and 0.08°C yr~(-1),respectively. For the warm temperature indices, the results indicated a significant upward trend for the annual maximum of maximum temperature, by 0.09°C yr~(-1), and the annual maximum of minimum temperature, by 0.11°C yr~(-1). The results for the total number of warm days and warm nights showed significant increasing trends of 5.02 d yr~(-1)and 6.92 d yr~(-1),respectively. For the cold temperature indices, there were upward trends for the annual minimum of maximum temperature,by 0.09°C yr~(-1), and the annual minimum of minimum temperature, by 0.03°C yr~(-1), concurrent with the decreases in the total number cold days (TX10P), with-3.80 d yr~(-1), and cold nights (TN10P), with-4.33 d yr~(-1). The 34°C and 37°C summer days results showed significant upward trends of 4.10 d yr~(-1) and 0.25 d yr~(-1), respectively. Overall, these findings showed upward warming trends in the Klang Valley, with the minimum temperature rate increasing more than that of the maximum temperature, especially in urban areas.     

Simultaneous adoption of risk management strategies to manage the catastrophic risk of maize farmers in Bangladesh

GeoJournal - Risk and uncertainty are distinctive features of agricultural cultivation, which significantly affect the production and income. Risk management is an important way for farmers to...     

Farm income,inequality, and poverty among farm families of a flood-prone area in Bangladesh: climate change vulnerability assessment

GeoJournal - This paper examines the farm income differences, income inequality of farm households, parameters of income variability that ascertain vulnerability levels, and cost-income variability...     

Effect of Face Losses and Cover-to-Diameter Ratio on Tunneling Induced Settlements in Soft Clay,Using Transparent Soil Models

Geotechnical and Geological Engineering - Reliable prediction of surface and subsurface settlements induced by shallow tunnels is important to minimize the adverse effects which may take...     

Geochemistry of ochreous precipitates from coal mine drainage in India

The deposition of ochreous is common by a consequence of acid mine drainage (AMD). The ochreous precipitated from the AMD sites around Tertiary coalfield of Assam, India were collected and characterized by X-ray diffractometry (XRD), Fe to S molar ratio, ammonium oxalate acid (pH 3.0) extraction, fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The ochreous mainly consists of goethite, schwertmannite, ferrihydrite and jarosite. Mineralogy of ochreous was controlled by the pH whereas formation of ferrihydrite was favored at high organic carbon content. Role of bacteria for the formation of secondary minerals was observed. Mobility of metals was controlled by the ochreous, and they were also retained during the process of phase transformation of poorly ordered iron-oxyhydroxysulfates into the stable forms.     

Sea level rise and tigers: predicted impacts to Bangladesh’s Sundarbans mangroves

The Sundarbans mangrove ecosystem, shared by India and Bangladesh, is recognized as a global priority for biodiversity conservation. Sea level rise, due to climate change, threatens the long term persistence of the Sundarbans forests and its biodiversity. Among the forests’ biota is the only tiger (Panthera tigris) population in the world adapted for life in mangrove forests. Prior predictions on the impacts of sea level rise on the Sundarbans have been hampered by coarse elevation data in this low-lying region, where every centimeter counts. Using high resolution elevation data, we estimate that with a 28 cm rise above 2000 sea levels, remaining tiger habitat in Bangladesh’s Sundarbans would decline by 96% and the number of breeding individuals would be reduced to less than 20. Assuming current sea level rise predictions and local conditions do not change, a 28 cm sea level rise is likely to occur in the next 50–90 years. If actions to both limit green house gas emissions and increase resilience of the Sundarbans are not initiated soon, the tigers of the Sundarbans may join the Arctic’s polar bears (Ursus maritimus) as early victims of climate change-induced habitat loss.     

Socio-structural forces predicting global water footprint: socio-hydrology and ecologically unequal exchange

ABSTRACT

Growth in water use and threatened shortages of water have become increasingly important in the modern world system. Natural resources are exploited extensively by capitalist interests in industrially advanced nations, while the lower strata of the world system, the underdeveloped societies, are left with limited access to natural resources for their productive processes, particularly water resources. We contribute to socio-hydrological research by examining underlying socio-structural factors that play a part in the process of deteriorating conditions of global water resources. Drawing on a world-systems perspective, this study examines how socio-structural forces – world-system position, per capita beef consumption, per capita energy consumption, and urbanization – affect per capita water footprint, which includes an accounting of “virtual water” consumption. We find that per capita beef consumption and per capita energy consumption have significant positive direct effects, and the world-system position has a significant indirect and total effect on per capita water footprint.     

The catastrophic cyclone of April 1991: Its Impact on the economy of Bangladesh

A very severe cyclonic storm with wind speeds of over 240 km/h struck the coastal areas of Bangladesh in the full moon night of 29 April 1991. The path of the eye, close to the shore, raised a storm surge of unusual height, reportedly more than 9 m above the mean sea level, which devastated the offshore islands and the mainland coast. The damage to the physical infrastructure of the port of Chittagong and adjoining industrial area has been colossal, and recovery will take years. Death tolls from the cyclone, storm surge and its aftermath exceeded 145 000 making it one of the world's major natural disasters of this century.This paper is concerned with examining the magnitude and intensity of the disaster. It analyses how the people of Bangladesh, and the environment in which they live, were affected by the cyclone. A brief account is presented of loss of life and of the damage suffered in various sectors, including agriculture, industry, and physical infrastructure.The paper lays emphasis on the need of building a sufficient number of multipurpose cyclone shelters in the disaster-prone coastal areas of Bangladesh. Adequate measures should be taken for evacuating people from vulnerable areas and putting them into these shelters in the event of a cyclonic storm. Simplification of the current cyclone warning system is recommended.The difficulties of providing relief to the survivors are discussed. And finally, the need for improvement of the communication infrastructure in the coastal areas is highlighted.     

Water and sediment quality, partial mass budget and effluent N loading in coastal brackishwater shrimp farms in Bangladesh

The present study aimed to quantify the water and sediment quality and growth and production parameters and to establish nutrient budgets for an average of five selected semi-intensive shrimp ponds in Bangladesh over a growing cycle. Physico-chemical parameters of water and sediments were measured and analyzed by standard methods. Gross yield (kg ha-1) of shrimp was calculated from the stocking and harvesting data. Finally, a partial nutrient mass budget for N and P was calculated. Most of the parameters of water and sediments correlated significantly with each other suggesting a high degree of interactions between different parameters in the system. Significantly higher concentrations of all species of nitrogenous nutrients were recorded in the effluent waters than that entering into the ponds. Therefore, a high loading and net output of nitrogenous nutrients in effluent waters was documented. The study also indicated a net discharge of solids and minerals through effluent loading. However, significantly lower concentrations of phosphorus in the effluent water indicated a net retention and trapping of phosphatic nutrients in the environment. Total production ranged between 532.0 and 697.0 kg ha-1 cycle-1 and P. monodon production between 484.0 and 562.0 kg ha-1 cycle-1. Ponds gained nitrogen primarily from intake water (55%) and fertilizers (29%), and nitrogen was lost primarily from water exchange (78%) and harvested shrimp (12%). Phosphorus gain occurred mostly from intake water (52%) and fertilizers (25%), and phosphorus was lost primarily from water exchange (52%) and harvested shrimp (3.3%). About 10% of input nitrogen and 44% of phosphorus were not accounted for in measured losses, and presumably were fixed or metabolized in the system. On average, 78 g N was discharged to and 25 g P was removed from the surrounding water by the system for each kilogram of shrimp produced. Mean conversion of feed nitrogen and phosphorus to shrimp flesh averaged 74% and 40%, respectively. It was concluded that semi-intensive systems serve as net supplier of N to and net remover of P from the surrounding water.