Estimation of LAI and above-ground biomass in deciduous forests: Western Ghats of Karnataka, India

This study demonstrates the potentials of IRS P6 LISS-IV high-resolution multispectral sensor (IGFOV  6 m)-based estimation of biomass in the deciduous forests in the Western Ghats of Karnataka, India. Regression equations describing the relationship between IRS P6 LISS-IV data-based vegetation index (NDVI) and field measured leaf area index (ELAI) and estimated above-ground biomass (EAGB) were derived. Remote sensing (RS) data-based leaf area index (PLAI) image is generated using regression equation based on NDVI and ELAI (r² = 0.68, p ≤ 0.05). RS-based above-ground biomass (PAGB) image was generated based on regression equation developed between PLAI and EAGB (r² = 0.63, p ≤ 0.05). The mean value of estimated above-ground biomass and RS-based above-ground biomass in the study area are 280(±72.5) and 297.6(±55.2) Mg ha⁻¹, respectively. The regression models generated in the study between NDVI and LAI; LAI and biomass can also help in generating spatial biomass map using RS data alone. LISS-IV-based estimation of biophysical parameters can also be used for the validation of various coarse resolution satellite products derived from the ground-based measurements alone.     

An approximate projection of availability of the fresh groundwater resources in the South West district of NCT Delhi, India: a case study

The future availability and sustainability of fresh groundwater resources in the South West district of the national capital territory (NCT) Delhi, India, have been projected. Due to a rapid decline in groundwater level and quality, the district has been required by the Government of India to regulate development of groundwater resources. Shallow groundwater is mostly saline and water resources in the area are limited. The methodology applied here involves microzonation of the district in terms of thickness of fresh groundwater and then quantification of present and future availability of freshwater in different freshwater zones, including tentative timescales. The calculation method has been aided by data on historic trends in water level at representative groundwater monitoring stations, located either in fresh groundwater zones or near to them. It is estimated that the presently available 481 million m³ of resources will be reduced to 374 million m³ by year 2007 and to 303 million m³ by the year 2012, and by the year 2022 the district will have only 176 million m³ of available fresh groundwater resources.     

Avalanche hazard mitigation in east Karakoram mountains

Natural Hazards - Karakoram mountains range in north-western part of Himalayas is about 500 km in length and hosts some of the world’s highest peaks and longest glaciers. It is...     

Dynamical downscaling approach for wintertime seasonal-scale simulation over the Western Himalayas

The performance of RegCM4 for seasonal-scale simulation of winter circulation and associated precipitation over the Western Himalayas (WH) is examined. The model simulates the circulation features and precipitation in three distinct precipitation years reasonably well. It is found that the RMSE decreases and correlation coefficient increases in the precipitation simulations with the increase of model horizontal resolutions. The ETS and POD for the simulated precipitation also indicate that the performance of model is better at 30 km resolution than at 60 and 90 km resolutions. This improvement comes due to better representation of orography in the high-resolution model in which sharp orography gradient in the domain plays an important role in wintertime precipitation processes. A comparison of model-simulated precipitation with observed precipitation at 17 station locations has been carried out. Overall, the results suggest that 30 km model produced better skill in simulating the precipitation over the WH and this model is a useful tool for further regional downscaling studies.     

Biodegradation Studies on Acid Violet 19, a Triphenylmethane Dye,by Pseudomonas aeruginosa BCH

Acid violet 19 (AV) belongs to the triphenylmethane (TPM) class of dyes which are potentially mutagenic or carcinogenic. However, very little studies on biodegradation of AV were reported as compared to other TPM dyes such as malachite green and crystal violet. In this study, AV was decolorized up to 98% within 30 min by Pseudomonas aeruginosa BCH. The decolorization depends on the initial dye concentration, pH, and temperature. However, the dye was decolorized under wide pH and temperature ranges with an optimum of pH 7 and 30°C. Up to 250 mg L^?1 of dye was found to be tolerated and decolorized by this strain. It showed decolorization ability for seven repeated dye addition cycles. The effect of additional carbon sources on dye decolorization was studied in which mannitol containing medium showed decolorization in 15 min. Induction in the enzyme activities of laccase, NADH‐DCIP reductase, and veratryl alcohol oxidase (VAO) indicates their involvement in AV degradation. Various analytical studies viz. UV–VIS, HPTLC, HPLC, and FTIR confirmed the biodegradation of AV by the bacterium. Based on GC‐MS analysis, a possible degradation pathway for AV was proposed. The phytotoxicity studies using Phaseolus mungo and Sorghum vulgare revealed the less toxic nature of metabolites formed after AV degradation.     

Hydrogeological characterization of aquifer in palla flood plain of Delhi using integrated approach

The Yamuna flood plains spread across the northern part of Indian subcontinent is home to millions of people. The ever-growing population in these plains make it difficult to sustain the demand of freshwater resources. However, the productive aquifers of flood plains could provide solution for these issues. In this context, it is necessary to understand the aquifer characteristics. Thus, the paper attempts to characterize the aquifer in Palla area of the flood plain using integrated approach. Besides, grain size analysis and site-litholog study, the nature of aquifer material was also ascertained from bulk mineralogy of the sediments using X-Ray Diffraction. The aquifer parameters were estimated with help of long duration pumping test data. Moreover, the effect of pumping on salinity variation and hydrochemical facies evolution was also examined. The sand dominant, unconfined aquifer was estimated to have horizontal hydraulic conductivity in the range of 25 m/day and vertical hydraulic conductivity of 6–7 m /day. While the specific yield of the aquifer was estimated in the range of 0.07–0.08. It is observed that under conducive active flood plain environment, the given sand mineralogy at the site does not allow salinity increase in groundwater even after more than a decade of groundwater pumping. In fact, over years, hydrochemical facies have evolved towards Bicarbonate type. These things put together make the active flood plain aquifer a sustainable groundwater resource.     

Static Equilibrium of Screw Anchor Pile Under Lateral Load in Sands

The screw anchor piles are installed in ground by screwing which is done with the help of torque motors. In this paper, the lateral load capacity of screw anchor piles is examined through an experimental investigation carried on model piles embedded in dry sand. The tests were carried on screw anchor piles with different number of helices provided in continuation. Lateral loads were applied at different height above the soil surface. The embedment length of screw anchor piles was also varied to study the behaviour of screw anchor piles under lateral loads. Some tests were conducted on plain shaft pile to compare the lateral load capacity of screw anchor piles with that of plain shaft piles. An empirical equation for computation of lateral loads has been developed considering lateral resistance, bearing resistance, uplift resistance and lateral resistance offered by soil in pile on the basis of experimental results. A theoretical model for predicting lateral load capacity of screw anchor piles in dry sand, consistent with the experimental findings has been developed in this study.     

Perception and knowledge about climate change and health problems: a study in Kolkata Metropolitan Region

In the twenty-first century, land use changes, massive expansion of urbanization, population growth, economic crisis, environmental issues are the main challenges of developing countries. Climate change and its effects on human health are the major concerns for the different age groups of the population. The study delved into the causes associated with climate change and climate change-related myriad health impacts on the study population. This study has used a concurrent mixed-method research design. The quantitative and qualitative data were collected from the study area. Perception and knowledge about climate change and its consequences on health was based on a quantitative approach of Bi-variate analysis and Chi-Square test and Fisher’s exact test; this study also used qualitative data analysis. Study results show that most respondents pointed out that temperature increases throughout the year and 90% of the respondents reported that rainfall pattern has also changed. Similarly, 65% of respondents agreed in their statements in favour of increased natural calamities in this region. The study findings show that more than 40% of population faces dengue fever and 10% of people also suffer from malaria. More than 60% of the urban population suffered from asthma. Similarly, more than 70% of the population also got affected by cold and cough due to weather variability. Focus Group Discussion (FGD) and In-depth interviews of the participants also affirmed the fact that climate variability induced diseases and health problems in Kolkata Metropolitan areas. Urban residents perceived that excessive urbanization contributes to the changes in regional climate and human health. The study will encourage the policy-makers and local government to mitigate adverse health effects driven by climate change in the Kolkata Metropolitan Region.

     

Identification of cross-valley faults in the Maynardville Limestone,Oak Ridge Reservation,Tennessee, using seismic refraction tomography

First arrival times from P-wave refraction and reflection seismic surveys along Bear Creek Valley on the Oak Ridge Reservation, Tennessee, were inverted to produce refraction tomographic velocity images showing seismic velocity variations within thinly mantled karstic bedrock to a depth of approximately 20 m. Inverted velocities are consistent with two distinct bedrock groups: the Nolichucky Shale (2,730–5,150 m/s) and Maynardville Limestone (3,940–7,575 m/s). Low-velocity zones (2,700–4,000 m/s) in the tomographic images correspond to previously inferred cross-valley strike-slip faults; in places, these faults create permeability barriers that offset or block groundwater flowing along Bear Creek Valley. These faults may also force groundwater contaminants, such as dense non-aqueous phase liquids, to migrate laterally or downward, spreading contamination throughout the groundwater system. Other, previously unmapped cross-valley faults may also be visible in the tomographic images. Borehole logs suggest the low-velocity values are caused by low rigidity fractured and vuggy rock, water zones, cavities and collapse features. Surface streams, including Bear Creek, tend to lie directly above these low-velocity zones, suggesting fault and fracture control of surface drainage, in addition to the subsurface flow system. In some cases, fault zones are also associated with bedrock depressions and thicker accumulations of unconsolidated sediment.