Mapping the Extent of Agroforestry Area in Different Altitudes of Tehri District,North Western Himalaya,India Through GIS and Remote Sensing Data

Assessment of area under agroforestry in Tehri district of North Western Himalaya, Uttarakhand, India has been done using GIS and remote sensing technology. The study district characterized by hilly terrain with varying elevations from 288 m to more than 2800 m and generally gentle slopes, valleys, flat land covers and agricultural terraces. High-resolution satellite imageries (spatial resolution 5.8 m) were used in this study for land uses and land covers classification. According to unsupervised classification, highest area was found under forest class (65.22%) followed by cropland (20.41%). Considerable area was also found under snow cover (9.45%) in the district. Area under agroforestry was estimated to be 5572.26 ha (1.53%) by this method, whereas it was estimated to be 7029.06 ha (1.93%) by supervised classification. Estimated cropland area comes out to be about 20.0%. An accuracy of 86.5% was found in this classification for agroforestry class. Highest area under agroforestry of 3707.36 ha was obtained in 1200–2000 m elevations followed by 2231.26 ha in 288–1200 m elevations. Negligible area was found on high elevation zones of more than 2800 m. The major agroforestry systems of dominated by Grewia oppositifolia (Bhimal), Celtis australis (Kharik) and Quercus leucotrichophora (Banj) were identified and mapped and remaining systems were grouped as others class. Estimated area under G. oppositifolia, C. australis and Q. leucotrichophora based systems come out to be 2330.82, 1456.80 and 1129.10 ha, respectively. These systems are multiple usufructs are food, fuelwood, fodder, fiber and small timber. It has been observed from the accuracy assessment that the estimates of area under agroforestry obtained under this study are reliable.     

Variability of Altimetric Range Correction Parameters over Indian Tropical Region using JASON-1 & JASON-2 Radar Altimeters

Region-specific atmospheric range correction maps are generated over the Indian tropical region from Jason-1 & Jason-2 radar altimeters data. Seasonal and spatial variability of wet tropospheric correction (WTC), ionospheric correction (IC), dry tropospheric correction (DTC), and sea state bias (SSB) correction are analyzed over the Bay of Bengal and the Arabian Sea. Two year atmospheric range correction data from JASON-1 (2008) & JASON-2 altimeters (2009) has been analyzed where each Jason cycle is exactly 9.9156?days repeat. The monthly and yearly mean variation of the range correction parameters has been studied over the Indian continent. For precise study, four different regions were selected as the Region of Interest in the North & South of the Arabian Sea and Bay of Bengal. WTC, Significant Wave Height (SWH), Wind Speed (WS) and SSB show the higher values during monsoon months. The yearly mean WTC over Indian Tropical region was 26.22?cm in 2008 and 26.20?cm in 2009. SSB Correction values mainly depend on the SWH and wind speed. The yearly mean SSB correction over Indian Tropical region was 6.87?cm in 2008 and 7.02?cm in 2009. DTC values are less during monsoon season and it shows a high value in the month of January. The yearly mean DTC over Indian Tropical region was 230.42?cm in 2008 and 230.43?cm in 2009.The IC values mainly depend on frequency and total electron content (TEC) in the ionosphere which further depends on the solar activity. The yearly mean IC over Indian Tropical region was higher in 2008 (2.98?cm) in comparison to mean IC in 2009 (2.29?cm). This study is useful to understand the variability of atmospheric correction parameters especially over Indian continent.     

Estimation of source parameters of Chamoli Earthquake, India

The devastating earthquake (mb = 6.6) at Chamoli, Garhwal Himalaya, which occurred in the morning hours on 29th March 1999, was recorded on Delhi Strong Motion Accelerograph (DSMA) Network operated by the Central Building Research Institute, Roorkee. In this paper the source parameters of this event calculated from the Strong Motion Data are presented. The seismic moment for this event has been found to be of the order of 10²⁵ dyne.cm and the moment magnitude has been calculated in the range of 6.53–6.69 at different stations. The stress drop and source radius for the earthquake are also calculated.     

A comprehensive and quantitative assessment of Raunthi Gad flash flood,Rishi Ganga catchment,central Himalaya,Uttarakhand, India

Natural Hazards - Drought severity is increasing in Southern Africa which is affecting rain-fed agriculture, the main source of livelihood in most countries in this region. The study assessed the...     

Utilities of Virtual 3D City Models Based on CityGML: Various Use Cases

Virtual 3D city models are increasingly being used to model the realms of the real world for utilization in a number of applications related to environmental simulations including, urban planning, mapping the energy characteristics of buildings, noise mapping, flood modelling, etc. Apart from geometric and appearance/textural information, these applications have a requirement for complex urban semantics. Currently, a number of 3D standards are available in CAD, BIM and GIS related domains for the storage, visualization and transfer of 3D geospatial datasets. Initially, the 3D data models (such as COLLADA, VRML, X3D, etc.) were purely graphical/geometrical in nature and mainly used for visualization purposes. With the inclusion of thematic modules in OGC CityGML, the integration of geometry and semantics in a single data model paved the way for better sharing of virtual 3D city models. In spite of the availability of a wide range of 3D data standards, there are certain differences with respect to geometry, topology, semantics, LODs, etc., which complicates the integration of 3D geodata from heterogeneous sources. This paper serves to highlights the need for the innovative solutions with respect to the urban environmental related simulations primarily based on the use of virtual 3D city models. Four use cases are studied in this context namely, (1) urban solar potential estimation using CityGML models, (2) simulation of traffic noise level mapped on building walls from the urban road segments, (3) CityGML based 3D data models interoperability, and (4) 3D indoor logistics and subsurface utilities. However, for modelling majority of use cases, CityGML does not provide explicit thematic representations but provides support for extending the CityGML schema using Application Domain Extensions. In a nutshell, the study explores the semantic modelling capabilities of the CityGML for the transformation of native 3D virtual city models to one satisfying capabilities like semantic information and support towards interoperability.     

Investigations on a Large Collection of Cosmic Dust From the Central Indian Ocean

We collected 1,245 spherules from the Central Indian Ocean basin by Magnetic cosmic dust collection (MACDUC) experiment raking the deep sea floor. This collection ranks among the large deep sea collections of cosmic dust. For this study, 168 particles are analyzed with SEM-EDS to characterise their cosmic nature and identify the processes that their morphological features, textures and chemical compositions reveal. All the three basic types of cosmic spherules have been identified: I-type, S-type and the G-type. The silicate or the S-type spherules are dominant in this collection. In all, 115 spherules were sectioned, polished and analyzed for major elements. I-type spherules are mainly composed of Fe and Ni oxides, some have metallic cores where appreciable amounts of Co is observed in addition to glassy phases with lithophile elements are also observed in these spherules. These evidences are supportive of the view that the I-type spherules could be metal grains from carbonaceous/unequilibrated chondritic bodies. The S-type spherules show elemental composition of Mg, Al, Si, Ca, Fe, and Ni approximately similar to chondritic compositions. In addition, some other rare particles such as an S-type sphere which contains a large zoned relict chromite crystal, other spheres with a semi-porphyritic/barred olivine texture are also observed. While most the S-type spherules appear to have carbonaceous chondrites as their parent bodies, the relict grain bearing spherule shows distinctly an ordinary chondritic parent body.     

Effects of rainwater-harvesting-induced artificial recharge on the groundwater of wells in Rajasthan, India

In light of the increasing deterioration of groundwater supplies in Rajasthan, India, rainwater harvesting practices in southern Rajasthan were studied to determine the effects of artificially recharged groundwater on the supply and quality of local groundwater. A physical and geochemical investigation utilizing environmental tracers (δ¹⁸O and Cl^–), groundwater level and groundwater quality measurements, and geological surveys was conducted with two objectives: (1) to quantify the proportion of artificially recharged groundwater in wells located near rainwater harvesting structures and (2) to examine potential effects of artificial recharge on the quality of groundwater in these wells. A geochemical mixing model revealed that the proportion of artificial recharge in these wells ranged from 0 to 75%. Groundwater tracer, water table, and geological data provided evidence of complex groundwater flow and were used to explain the spatial distribution of artificial recharge. Furthermore, wells receiving artificial recharge had improved groundwater quality. Statistical analysis revealed a significant difference between the water quality in these wells and wells determined not to receive artificial recharge, for electrical conductivity and SO ₄ ^– . The findings from this study provide quantitative evidence that rainwater harvesting structures in southern Rajasthan influence the groundwater supply and quality of nearby wells by artificially recharging local groundwater.     

Systemic analysis of soil microbiome deciphers anthropogenic influence on soil ecology and ecosystem functioning

Soil is a complex ecosystem with defined microbial community signatures, modulated by the interaction between biotic and abiotic factors. Amidst biotic factors, land usage have significant impact onto the soil microbial structure and ecosystem functioning. In the current study, metagenomic approach was used to decipher effect of hospital settings on soil microbiome structure and physiological functions. Physico-chemical properties analysis revealed that key elements for maintenance of soil microflora, such as organic carbon, nitrogen, phosphorus and sulfur were relatively diminished within hospital soil, compared to garden soil. Comparative microbial diversity analysis with 97,315 SSU rRNA gene sequences generated from both the soil samples highlight relatively low microbial diversity, with an enrichment for Acidobacteria and Bacteroidetes and decreased Proteobacteria/Acidobacteria ratio. Comparative shotgun metagenome sequence analysis further revealed a shift in the physiological role of soil microbiomes with change in soil usage. Genes for carbohydrate, sulfur, potassium and nitrogen metabolism were significantly (q value <0.05) higher in the garden soil; while the genes for phage, plasmid DNA, transposon and aromatic compound metabolism were significantly enriched within hospital soil. Thus, the current study highlights a correlation between soil biochemistry and microbial ecology based on land usage.     

Ultra-low-frequency (ULF) and total electron content (TEC) anomalies observed at Agra and their association with regional earthquakes

Employing a three-component search coil magnetometer (f = 0.01–30 Hz) the ultra-low-frequency (ULF) magnetic field observations have been taken in a noise free rural site at Bichpuri, Agra, India since 20 April 2007. We have analysed 7 months of night time data from 01 May to 30 November 2007. The data show seven occurrences of ULF bursts with periods ranging from a few minutes to an hour in a wide frequency range up to 15 Hz. The occurrence of such ULF bursts has been statistically analysed. The polarization parameter analysis shows that two of these bursts occurred from sources in the ionosphere and magnetosphere (Z/X < 1). It is further seen that four bursts correlated very well with some regional earthquakes (M > 4.5), which occurred at distances less than 628 km from the observation site at Agra. In some cases the bursts occurred 1–3 days prior to the main shocks.Since earthquakes are also known to perturb the ionosphere, we have analysed total electron content (TEC) data obtained from a GPS receiver stationed at Agra since June 2006. Analysis of the data for the same period as the magnetic field observations shows that there existed TEC anomalies on all the days when ULF bursts occurred. The TEC anomalies show enhancement and depletion in the data in all cases. While the mechanisms of the ULF and TEC anomalies are not well known, it is expected that the ULF bursts occurred due to microfracturing of the earth's crust during stress accumulation and that the TEC anomalies occurred as a result of the electric field induced in the ionosphere during such processes.