This article investigated the principal reason for water circulations in the Caspian Sea. Unlike other inland water bodies, and similar to the open seas, the Caspian Sea shows regular water circulations which are not explained by the wind. The Steric contribution of water level fluctuations was studied in this article by two approaches: one from remote sensing and climatology data, and the other, from space altimetry and gravimetry data. The approaches are fundamentally different: the first approach directly observes and measures the steric fluctuations, while, the second approach estimates the steric fluctuations by analysing their causing factors such as water temperature and salinity. Analysis of over 13 years data showed that estimations from these two approaches are consistent. Based on the results, the Steric Sea Level (SSL) included a seasonal cycle of about 8.5 cm and a seasonal topography of 4 and 7 cm in winter and summer respectively. The seasonal water circulations observed in the lake was consistent with the geostrophic response to estimated steric topography. Moreover, the results demonstrated that the seasonal water surface topography is the reason for water circulation in the Caspian Sea.
Electrical resistivity method for groundwater investigation using vertical electrical sounding (VES) technique was carried out in parts of Afugiri in Umuahia-North Local Government Area of Abia State. The major aim is to delineate the aquiferous units within the study area by determining their thickness, resistivities and the potential borehole depths. The geology revealed that the study area is sedimentary environment and predominantly Bende-Ameki Formation. Prior to this study, there had been serious speculation that borehole could not thrive within the study area (mainly Afugiri). Actually, there had been no existing borehole in the area. Twelve vertical electrical soundings using the Schlumberger configuration were carried out within the study area. The data obtained were interpreted using computer software (IPI2WIN) and Surfer 8 for contouring and map production. The subsurface area investigated is made up of 5-7 geoelectric layers which are not of uniform thickness as revealed by the correlated geoelectric section. In Afugiri, the resistivity values and signatures in Vertical Electrical Sounding Stations (VES 1 and VES 3) show that they are likely to hold water at depths of 61.1 and 27.3 meters respectively. The likely aquiferous zone in VES 1 has a thickness of about 32.2 meters while the thickness of the aquiferous unit in VES 3 is about 9.61 meters. The electrical properties of VES 1 and VES 3 shows that they are likely to be sand or fractured shales. The resistivity values of the likely aquiferous zones in VES 1 and VES 3 range from about 2000 to 440,000 Ω-m. `It is recommended that boreholes be drilled much beyond the depth range of 17 m to 229 m which represent the range of water table in the study area to harness potable water within the aquifer region.
The Adi Ganga River is a paleodistributary of the Bhagirathi-Hugli River, and was once an important navigational channel according to Medieval Bengali literature. Many European merchants and travellers also travelled through the Adi Ganga by vessels to the port of Kolkata. Local people also carried various items from the Sundarban via Adi Ganga. Previously, earthen embankments and natural levees existed at different sites along the river. But now, due to unprecedented urban growth, the river is sandwiched on both sides. After the partition of Bengal, many refugees occupied the riverbanks and constructed huts. The river bed is converted into a built-up area in some places. Once it was lifeline of the people of the Bengal delta, but the lower stretch has been reclaimed. Previously the rainwater of Kolkata was discharged through different small outlets into Adi Ganga river. At present, the riverside land use patterns have been entirely modified. As a result, flooding has become a common problem during monsoon period. Several fluvial parameters are analysed to assess the present fluvio-dynamic status and the decay of the Adi Ganga River. The present study aims at the detection of the changing scenario of fluvial geometry of the Adi Ganga. The research work is mainly based on collected and thoroughly analysed primary data. The study on the fluvio-dynamics of the Adi Ganga River revealed that the fluvial geometry has been changing unto the fate of ultimate deterioration.
The cities are growing in all directions resulting in urban sprawl, and it is governed by geographic and socio-economic factors such as population growth, policy and economic development. The uncontrolled momentum of urban sprawl and land use change raises many issues which might have both positive and negative impacts. This sprawl can be adequately monitored using remotely sensed data from different dates by digital analysis of the imagery using change detection techniques. The present study aims to examine the change in demography, land use /land cover (LU/LC) over a time point and assesses the pattern of sprawl through GIS technique of Varanasi city. The geographical area is 1535 sq.km including 1,371.22 km² rural area and 163.78 km² urban area. Varanasi has a population of 36, 76,841 persons in 2011. There are 5, 60,162 houses in the district. It consists of 8 blocks. The spatio-temporal study of LU/LC is carried out for two-time points 1990and 2016. The data source used for analysis is Landsat MSS and Landsat OLI. The analysis mainly focused the urban growth along with land use/ landcover changes using digital image processing techniques like Maximum Likelihood Classifier algorithm for Supervised Classification and NDVI vegetation index. The trend of sprawl is notably high in the urban centers than in the revenue villages.
In this Review, we aim to reveal an unrecognised source of causality leading to increases in combustibility, intensity, and the extent of California, United States of America wildfires, and the concomitant harm to human and environmental health. We review literature, including scientific and medical, and evidence, including photographic, of near-daily, near-global jet-spraying particulates in the atmosphere as related to wildfires. We review the evidence that atmospheric manipulation utilising aerosolised coal fly ash is a primary factor in the extent and severity of forest fires in California and elsewhere; adverse effects include exacerbation of drought, tree and vegetation die-off and desiccation, and unnaturally heating the atmosphere and surface regions of Earth. Forest combustibility is increased by moisture-absorbing aerosolised particles that damage the waxy coatings of leaves and needles, reducing their tolerance to drought. The aerial climate manipulation using coal fly ash greatly increases the potential for forest fire ignition by lightening. Wildfires dramatically worsen baseline air pollution, emitting harmful gases and volatile organic compounds, and they both concentrate and re-emit toxic elements and radioactive nuclides over a wide area. The type of air pollution created by wildfires is associated with increased all-cause mortality, with the greatest impact on respiratory and cardiovascular disease. Studies have shown that aerosolised coal fly ash is an important risk factor for chronic lung disease, lung cancer and neurodegenerative disease. Failure to recognise multifold adverse consequences of jet-spraying particulates into the atmosphere, we submit, will continue the progression of ever-accelerating ecological disasters.