Aim: Estimation of the glacial debris size from the Synthetic Aperture Radar (SAR) data is the primary objective of the study. The debris cover is of interest to glaciologists due to its influence on the glacier melt processes. Previous studies show a negative correlation between thicknesses of supra-glacial debris melting of glacial mass.
Study Area: This study involves collection of debris size information from the Chhota Shigri glacier of Himachal Pradesh during the year 2014. The developed model is tested to detect supra-glacial debris size over the Gangotri and Zemu glaciers.
Methodology: Backscattering signals of the SAR data from the ground truth sites are correlated with debris size. A linear regression was identified and used to detect the distribution of debris size from SAR backscattering. Satellite data of RISAT-1 Medium Resolution SAR mode is the primary input. A Surface profiler is used to collect the in-situ data of debris. Predicted debris size has been cross-check by measured debris size from high resolution optical data.
Results: From the model derived outputs, the average debris size of the Gangotri glacier is around 100 – 200 mm and that of the Zemu glacier is around 300 – 400 mm.
Conclusion: Co and cross polarized SAR data are employed to derived debris size; however, cross polarized SAR backscattering has better correlation with debris size. The accuracy of the results derived from the developed method is ± 50 mm. The rugged terrain of the mountain glaciers limits collection of in-situ data. Use of satellite data can overcome this limitation to some extent and help to understand the role of debris in glacier mass balance.
The environment, in its natural sense, often refers to our biophysical surroundings and man is in continuous interaction with it for its very existence. However, man-environment relationship has many dimensions- physical, social, economic, political, and even temporal- in terms of how we are currently affected by past decisions and how our decisions will affect us and our coming generations in future. When risk assessment was in its infancy in the 1960s, the general assumption was that the major cause of a problem could easily be identified and a solution generated. As time has progressed and society and science have faced new problems, this assumption is no longer applicable to the decision-making process. Thus, society is currently at a crossroads in environmental decision making, and there is a need to carefully examine the current paradigm and think about what our scientists and social scientist can do to improve the way decisions are made. This paper highlights different approaches to environmental decision making and opportunities to improve decision making under complex situations and circumstances.
Land suitability analysis for agriculture plays a key role in sustainable agricultural production. The aim of this study is to develop suitability maps for major agricultural crops using multi-criteria spatial analysis for Aiyar basin - a sub-basin of Cauvery basin in Central Tamil Nadu as a case study. The main criteria such as soil, topography, irrigation and socio-economic factors and 18 sub-criteria (soil depth, drainage, texture, pH, salinity, sodicity, CEC, organic carbon, base saturation, slope, erosion, geomorphology, canal, groundwater, irrigation intensity, agricultural labour availability, cultivators and agricultural credit banks) were used for the suitability analysis. All the criteria used for the suitability classification were not equally important; each criterion would contribute towards the crop growth and yield at different levels. Hence, the relative importance of these criteria was formulated on the basis of the guidelines of the National Bureau of Soil Survey and Land Use Planning (NBSS & LUP) as adapted to local conditions. The Geographic Information System (GIS) based Analytical Hierarchy Process (AHP) method was used to determine the weight and rating for each criterion. Then the criterion layers were classified into four suitability classes which were high (S1), moderate (S2), marginal (S3), and not suitable (N). After the spatial overlaying of all criterion layers, crop-land suitability maps for paddy, pulses, maize and cashew were prepared. The results revealed that 18.93 %, 22.34 %, 20.37 % and 19.89 % of the study area were highly suitable for cultivating paddy, pulses, maize and cashew respectively. The results of suitability analysis could provide assistance for local farmers and decision makers to select suitable crops that are most adaptable to the land characteristics.
Abattoir wastewater contains nitrate concentration, which is toxic to the environment when discharged without treatment, adsorption is one of the effective methods for removal of nitrate in abattoir wastewater. The aim of this research work is to study the kinetics of nitrate removal in a packed bed column. The effluent from a waste water treatment plant was treated with crushed bone activated carbon (CBAC) in a packed bed and the adsorption performance of the packed bed for the removal of nitrate was investigated by varying various parameters such as pH, bed heights and particle size. The results indicate that the adsorption efficiency increased from 67.44% to 88.82% with increase in pH from 2 to 12, increased from 95.57% to 97.08% with increase in bed height from 10 to 30 cm and decreased from 95.58% to 90.54% with increase in particle size from 850 to 450 µm. The adsorption kinetics was analyzed using Thomas and Yoon-Nelson kinetic models. For bed heights of 10, 20 and 30 cm analyzed using Yoon-nelson model, adsorption time τ was 381.16, 428 and 464.34 min-1 respectively and Yoon-Nelson constant KYN was 0.0037, 0.0036 and 0.0035 min-1 respectively, indicating that as bed height increased, τ increased and KYN decreased. For Thomas model where bed heights of 10, 20 and 30 cm were used maximum adsorption capacity q0 was 311.66, 174.84 and 126.57 mg/g respectively and Thomas constant KTH was 0.0037, 0.0036 and 0.0035 respectively, indicating that as bed height increased q0 and KTH decreased.
This study, is to estimate the curie point depth, heat flow and geothermal gradient using spectral analysis and empirical formula of aeromagnetic data, over Mubi and Environs, north-eastern part of Nigeria. The Aeromagnetic data was divided into equal interval of 15'' by 15’’. The results of curie point depth obtained varies between 9.48 and 10.33km, geothermal gradient varies between 21 and 24°C km-1, while the heat flow varies between 52 and 60 mWm-2. The relationship between curie depth and heat flow is an inverse linear while the geothermal gradient is proportional to the heat flow in the study area. These results are consistent with the prevailing geotectonic regime in the study area. However, this study illustrates that surface magnetic data can be used to produce Curie point depth estimate even for region with paucity of heat flow and geothermal gradient data.