Identification of Groundwater Potential Zones using Remote Sensing and GIS of K-J Watershed,India

Groundwater potential zone mapping has become easier with the inputs from Remote Sensing (RS) & Geographical Information System (GIS) techniques. Various thematic maps like geology, geomorphology, drainage density, slope, landuse/landcover etc can be easily generated through RS & GIS. The present study is aimed at generating groundwater potential map of Koshalya-Jhajhara (K-J) watershed by using integrated approach of RS & GIS. Various thematic layers have been generated and assigned weightages and ranks. These layers have been integrated in GIS software for generating Groundwater Potential Zone (GPZ) map of K-J watershed. The area falls into five categories of groundwater potential zones i.e. very good, good, moderate, poor and very Poor depending on the likelihood of availability of ground water. On the basis of this study it is found that only 5.83 km² and 4.91 km² area is under very good and good category of groundwater availability respectively. An area of 24.48 km² is found under moderate category whereas dominant portion of K-J watershed i.e. 61.83 km² and 37.87 km² area falls under poor and very poor category of availability of groundwater respectively.     

Assessing coastal landscape vulnerability using geospatial techniques along Vizianagaram–Srikakulam coast of Andhra Pradesh,India

Vizianagaram–Srikakulam coastal shoreline consisting of beaches, mangrove swamps, tidal channel and mudflats is one of the vulnerable coasts in Andhra Pradesh, India. Five site-specific parameters, namely rate of geomorphology, coastal elevation, coastal slope, shoreline change and mean significant wave height, were chosen for constructing coastal vulnerability index and assessing coastal landscape vulnerability. The findings revealed a shift of 2.5 km in shoreline towards the land surface because of constant erosion and that of 1.82 km towards the sea due to accretion during 1997–2017. The rate of high erosion was found in zones IV and V, and high accretion was found in zones II and III. Coastal vulnerability index analysis revealed constant erosion along shoreline and sea level rise in the study area. Most of the coast in zone V has recorded very high vulnerability due to erosion, high slope, significant wave height and sea level rise. Erosion and accretion, significant wave height, sea level rise and slope are attributed to high vulnerability in zones III and IV. Zone II recorded moderate vulnerability. Relatively lower slope, mean sea wave height and sea level rise have made this zone moderately vulnerable. Very low vulnerability was found in zone I, and low vulnerability was recorded in zone II. Accretion, low slope and low sea level rise were found to be causative factors of lower vulnerability. Thus, zones III, IV and V should be accorded higher priorities for coastal management. The findings can be helpful in coastal land planning and management and preparing emergency plans of the coastal ecosystems.     

Expansion of a glacial lake,Tsho Chubda,Chamkhar Chu Basin,Hindukush Himalaya,Bhutan

Natural Hazards - A wide range of methods for detection of glacial lakes and their expansions using multi-temporal remote sensing images have been employed in the past. This paper presents a...     

Policy making for renewable energy in India: lessons from wind and solar power sectors

It is clear that developing countries will have to be part of the global mitigation effort to avoid ‘dangerous climate change’, and, indeed, many of them are already undertaking significant actions on multiple fronts to help address this problem, even if they have not yet taken on legally binding commitment under the United Nations Framework Convention on Climate Change (UNFCCC). Since the deployment of GHG-mitigating technologies is already a significant part of this effort and likely to be even more so in the future, drawing lessons from existing programmes can help accelerate and enhance the effectiveness of this deployment process. Accordingly, this article aims to examine the deployment of wind and solar power in India, paying specific attention to the role of public policy in incentivizing and facilitating this deployment, how these policies have evolved over time, what has shaped this evolution, and what the learning has been over this period. Through this analysis, the intention is to draw out key lessons from India's experience with deployment policies and programmes in these two sectors and highlight the issues that will need to be given particular consideration in the design of future domestic policies and international cooperation programmes to enhance the move towards climate-compatible development in India. Many of these lessons should also be relevant for other developing countries that are attempting to balance their climate and developmental priorities through the deployment of renewable energy technologies.     

Mitigation of earthquake-induced damage of breakwater by geogrid-reinforced foundation

A strong earthquake often precedes a tsunami, and a breakwater may settle during the earthquake. Such seismic subsidence of the breakwater may reduce its ability to block the tsunami, and the tsunami may easily enter coastal areas by overflowing it. This study deals with the instability of a breakwater due to an earthquake. In addition, to protect a breakwater from damage caused by an earthquake, a new concept of using geogrid for reinforcing the foundation of a breakwater is introduced. To determine the behavior of unreinforced foundation and to evaluate the effectiveness of the proposed reinforced foundation under different earthquake loadings, a series of shaking table tests were performed. It was observed that the earthquake generated excess pore water pressures and deformations of foundation ground were main reasons of failure of the breakwater. The reinforced foundation was found effective to reduce the earthquake-induced damage of the breakwater, and finally it makes the breakwater resilient against earthquake-induced forces. Numerical simulations were also performed to elucidate the mechanism of reinforcement–breakwater–soil–water system under different earthquake loadings.     

Ecological consequences of land use change: Forest structure and regeneration across the forest-grassland ecotone in mountain pastures in Nepal

The ecotone, the spatial transition zone between two vegetation communities, is claimed to have more species than the adjoining communities. However, empirical studies do not always confirm higher richness at the ecotone. The ecotone position and structure are dynamic over time and space and it is driven by the changes in climate, land use or their interaction. In this context, we assessed the forest- grassland ecotone of temperate mountains in central Nepal by i） comparing species composition and richness across the ecotone, ii） analyzing if the forestgrassland ecotone is shifting towards the grassland center by colonizing them with trees, and iii） discussing the consequence of changed disturbance regime in the dynamics of this ecotone and the surrounding grasslands. We analyzed vegetation data sampled from belt transects laid across the forest- grassland ecotone in semi-natural grassland patches. Vegetation data consisting of species richness and composition, and size structure and regeneration of the two most dominant tree species, namely Rhododendron arboreum and Abies spectabilis, from the transects, were used to analyze the trend of the forest-grassland ecotone. Forest and grasslands were different in terms of floristic composition and diversity. Vascular plant speciesrichness linearly increased while moving from forest interior to grassland center. Spatial pattern of tree size structure and regeneration infers that forest boundary is advancing towards the grasslands at the expense of the grassland area, and tree establishment in the grasslands is part of a suceessional process. Temporally, tree establishment in grasslands started following the gradual decline in disturbance. We argue that local processes in terms of changed land use may best explain the phenomenon of ecotone shift and consequent forest expansion in these grasslands. We underpin the need for further research on the mechanism, rate and spatial extent of ecotone shift by using advaneed tools to understand the process indepth.     

Evaluation of the Soil Conservation Service curve number methodology using data from agricultural plots

The Soil Conservation Service curve number (SCS-CN) method, also known as the Natural Resources Conservation Service curve number (NRCS-CN) method, is popular for computing the volume of direct surface runoff for a given rainfall event. The performance of the SCS-CN method, based on large rainfall (P) and runoff (Q) datasets of United States watersheds, is evaluated using a large dataset of natural storm events from 27 agricultural plots in India. On the whole, the CN estimates from the National Engineering Handbook (chapter 4) tables do not match those derived from the observed P and Q datasets. As a result, the runoff prediction using former CNs was poor for the data of 22 (out of 24) plots. However, the match was little better for higher CN values, consistent with the general notion that the existing SCS-CN method performs better for high rainfall–runoff (high CN) events. Infiltration capacity (fc) was the main explanatory variable for runoff (or CN) production in study plots as it exhibited the expected inverse relationship between CN and fc. The plot-data optimization yielded initial abstraction coefficient (λ) values from 0 to 0.659 for the ordered dataset and 0 to 0.208 for the natural dataset (with 0 as the most frequent value). Mean and median λ values were, respectively, 0.030 and 0 for the natural rainfall–runoff dataset and 0.108 and 0 for the ordered rainfall–runoff dataset. Runoff estimation was very sensitive to λ and it improved consistently as λ changed from 0.2 to 0.03.     

Rayleigh waves in liquid layer resting over an initially stressed orthotropic half-space under self-weight

The study of surface waves (Rayleigh wave) finds their virtuous applications in a numerous geological and geophysical fields including water, oil, gas, and other subsurface geological probing and exploration. The present paper efforts to investigate the influence of initial stress, Earth magnetism, and gravity on propagation of Rayleigh waves. Considered model is consist of a liquid layer lying over a magnetoelastic orthotropic half-space under self-weight and initial stress. Method of separation of variable is used to solve the equation of motion. Solutions of governing equations are obtained in terms of displacement. Frequency relation for Rayleigh wave has been obtained and matched with classical Rayleigh wave equation. In addition to classical case, some existing results have been deduced as particular case of the present study. Obtained results have been shown through numerical illustrations. It is found that the considered parameters (initial stress, Earth magnetism, and gravity) have prominent effect on phase velocity of Rayleigh wave. Graphical representations have been made to exhibit the velocity profile of Rayleigh waves for different cases with the help of MATHEMATICA. The present study may be useful for seismologists and engineers who are concern with applications of wave propagation in magnetoelastic orthotropic medium.     

Demarcation of palaeochannels and integrated ground water resources mapping in parts of Hisar district,Haryana

Present study deals with the demarcation of palaeochannels and mapping of integrated water resources in parts of Hisar district, Haryana using Indian Remote Sensing Satellite (IRS-1D) LISS-III Data of December 21, 2001. The landforms identified are Sand Dune, Dune Complex, Aeolian Plain, Fluvioaeolian plain, Palaeochannel and Younger Alluvial Plain formed by aeolian, fluvio-aeolian, and fluvial processes. These palaeochannels are first time demarcated in the area. The ground water prospects of various geomorphic units have been assessed. Depth to water level and ground water quality maps were digitized and put in to GIS format. Ground water prospects and quality maps were integrated and depth to water level information was draped on it to prepare final integrated ground water resources map. This map depicts ground water prospects, quality and depth together in a single map, which will help in and ground water exploration.     

Water Quality Assessment Using Physicochemical and Bacteriological Parameters of Fateh Sagar Lake,Udaipur, India

In the present study assessment of physicochemical and bacteriological parameters of Lake Fateh Sagar of Udaipur (Rajasthan), India was done. Water samples were collected during different seasons for analysis of physicochemical parameters such as pH, temperature, total alkalinity, total hardness, dissolved oxygen, biological oxygen demand and chemical oxygen demand. In addition, the bacteriological analysis like total bacterial and coliform count was detected. Incidences of Escherichia coli and their antibiotic resistance pattern were analyzed, which is the major microbiological indicator of faecal contamination. The values of some physicochemical and many of the bacteriological parameters were found above the permissible limits for drinking water recommended by World Health Organization. E. coli isolates were identified by morphological, biochemical and molecular characteristics using E. coli specific 16S rRNA gene based primers namely 16E1, 16E2 and 16E3 and universal primers namely 27F and 1492R by PCR. It was found that most of E. coli strains were strongly resistant to kanamycin, ampicillin, cefixime, polymyxin B, penicillin, vancomycin, rifampicin and streptomycin. The study of water quality is of significant value because the drinking water supply of the city is dependent on this lake and present study indicated that the lake water is polluted with reference to these analyzed parameters.