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Land degradation is decline in productivity of land in terms of bio-diversity and economy, resulting from various causes including climate and human dominance, leading to loss of ecosystem. It is an issue of global concern and threatens productivity of land, water, biodiversity, ecology, economy, and people. India, with 2.4% of global land area, is homeland for around 18% of global human population and 30.4% livestock population, supporting more than 8% of world’s agriculture with more than 69% area falling under drylands. The blend of high population, high agriculture production and diverse agro-climatic conditions results in excessive pressure on resources. This study is an attempt to access land degradation vulnerability considering human-induced factors, biophysical and climate parameters. Hierarchy-based indexing method is used for analysis using geospatial technique. Study reveals that around 67% of the land area falls under high vulnerability, and 27% area falls under moderate vulnerability. The outcome was further compared with MODIS land surface temperature and normalised difference vegetation index data for validation and is observed that more than 85% area under moderate–high vulnerability is related to increase in surface temperature and/or no-change in vegetation index; this area also falls under low NDVI value range (

We used Airborne Visible Infrared Imaging Spectrometer-Next Generation data for mapping possible mineral alterations, which aid in mineral exploration over larger areas. The data were subjected to various advanced processing techniques like Minimum Noise Fraction, Pixel Purity Index, N-Dimensional visualization and Spectral angle mapper classification. End-member spectra were matched with those of the minerals as available in the United States Geological Survey Spectral Library. In the present study, the Ambaji–Deri area of northwestern India was mapped for mineral alterations. The area has thick forest cover along with rugged topography, which warranted the use of hyperspectral remote sensing approach. The minerals such as calcite, muscovite and chlorite have been mapped, which are showing a good correlation with the ground geological records, barring epidote, whose distribution is scattered. We attribute the possible reason to be the spectral similarities between epidote and chlorite, which makes them difficult to differentiate only on the basis of the present hyperspectral study. The hyperspectral technique, as illustrated, provides powerful tool for mapping mineral alteration to mineral deposits. This enables scrutiny of a wider area of interest to being narrowed down for first-hand field investigations.

Coastal areas are dynamic transition zones between land and sea. Their vulnerability is increasing due to human interventions with the natural processes. In the present study, we focused on coastal vulnerability assessment along Karnataka, south-west coast of India to identify the erosion-prone areas by integrating thematic datasets such as shoreline dynamics, land-use/land-cover, geomorphology, geology, elevation and bathymetry using remote sensing and GIS techniques. The 304 km coastline of Karnataka is divided into fourteen littoral cells, and each into a number of transects at uniform intervals. In this coastal stretch, ~ 265 km (87%) is vulnerable to erosion of which ~ 179.5 km (59%) is undergoing erosion at various magnitudes. Littoral cells in the south are subjected to high erosion and vulnerability, and the areas having human interventions are the most erosion-prone. This approach provides valuable information on the degree of potential vulnerability risk which serves as a guide to develop adaptation measures by the coastal zone management authority.

Radargrammetry technique using the stereoscopic synthetic aperture radar (SAR) images is used for the generation of a digital elevation model (DEM) of a region requires only the amplitude images. SAR stereoscopic technique is analogous to the stereo-photogrammetric technique where the optical stereoscopic images are used for DEM generation. While the advantages of the SAR images are their indifference to atmospheric transparency and solar illumination conditions, the side-looking geometry of the SAR increases the complexity in the SAR stereo analysis. The availability of high spatial and temporal resolution SAR data in recent years has facilitated generation of high-resolution DEM with greater vertical accuracy using radargrammetric technique. In the present study, attempt has been made to generate the DEM of Dehra Dun region, India, from the COSMO-Skymed X-band SAR data-pair acquired at 8 days interval through the radargrammetry technique. Here, radargrammetric orientation approach has been adopted to generate the DEM and various issues and processing steps with the radargrammetry technique have been discussed. The DEM was validated with ground measured elevation values using a differential global positioning system and the root-mean-square error of the DEM was found as 7.3 m. The DEM was compared with the reference DEM of the study area generated from the Cartosat-1 stereo data with a model accuracy of 4 m.

Monitoring of seasonal snow cover is important for many applications such as melt runoff estimation, climate change studies and strategic requirements. Contribution of seasonal snow melt runoff of Chenab River is significant and important to meet hydrological requirement at foothills. Seasonal snow cover of Chandra, Bhaga, Miyar, Bhut, Warwan and Ravi, six major tributaries of Chenab River, becomes crucial to assess the water availability. In addition, altitudinal distribution of snow cover significantly influences the melt runoff which is highly sensitive to minor variations in atmospheric temperature. In this investigation, remote sensing based Normalized Difference Snow Index technique has been used to generate 10 daily snow cover product. Snow cover monitoring of all the sub-basins were carried out for 10 years from 2004–2005 to 2013–2014 during hydrological year (October to June) using Advanced Wide Field Sensor (AWiFS) of Indian remote sensing satellite (IRS). Accumulation and ablation patterns of snow cover have also been analyzed for the six sub-basins. Accumulation and ablation pattern of snow cover, from 2004 to 2014 which shows slightly increasing trend for all the sub-basins. Meteorological data of Kelong at Bhaga sub-basin was also analysed. Average monthly snow line altitude was estimated for all the sub-basins using hypsographic curve. Chandra and Bhaga sub-basins are at higher altitude and Ravi sub-basin is at lower altitude. It was also observed that areal extent of snow reaches to lower altitude during last 5 years, particularly in Ravi sub-basin.

Shoreline changes along the south Gujarat coast has been analyzed by using USGS Digital Shoreline Analysis System (DSAS) version 4.3. Multi-temporal satellite images pertaining to 1972, 1990, 2001 and 2011 were used to extract the shoreline. The High water line (HTL) is considered as shoreline and visual interpretation of satellite imageries has been carried out to demarcate the HTL based on various geomorphology and land use & land cover features. The present study used the Linear Regression Method (LRR) to calculate shoreline change rate. Based on the rate of shoreline changes, the coastal stretches of study area has been classified in to high erosion, low erosion, stable, low accretion and high accretion coast. The study found that about 69.31 % of the South Gujarat coast is eroding, about 18.40 % of coast is stable and remaining 12.28 % of the coast is accreting in nature. Field investigation was carried out which confirmed the coastal erosion/accretion derived from the analysis. The high erosion area are mostly found along the Umergaon (near Fansa, Maroli, Nargol, Varili river mouth, Umergaon light house) and Pardi (Kolak, Udwara)Taluka in Valsad district. Stable coastal length of the study area is 21.59 km and mostly found in Nani Dandi and near Onjal. High accretion (3.70 %) was only found near Hajira and low accretion (8.58 %) are distributed the study area. The main causes of coastal erosion of the study area were the strong tidal currents accompanied by wave action and reduced the sediment load of the river.

Climate change due to anthropogenic forcing through escalating greenhouse gas emissions and destruction of carbon sinks by deforestation is leading to floods and droughts affecting agriculture production. Global warming induces steric as well as eustatic rise in sea-level, by thermal expansion and addition of ice-melt water, respectively. Although the IPCC (2007) estimated a maximum possible sea-level rise of about 59 cm, more recent estimates show a global average rise of ≥1 m by the 2100 AD. The low-lying coastal zones are more vulnerable to rising sea levels as they face submergence or saltwater intrusion which affects the agriculture activities. Geomatics-based models on the possible impact of the predicted sea-level rise on coastal agriculture are necessary to initiate appropriate mitigation plans. The present study is an attempt in this direction taking the Andhra Pradesh (AP) coast as an example. The land use / land cover of the AP coast was mapped through the interpretation of IRS-P6 LISS III imagery from 2008. SRTM digital elevation models coupled with landform evidences have been used to interpolate contours at 0.5 m interval, although highly approximate, for the entire coastal region. If the sea level rises by 1.0 m, about 4040 km2 area including the present intertidal wetlands as well as the land between the present and future high tide lines would be affected along the entire 1030-km-long AP coast displacing about 1.67 million inhabitants and their economic activities, in about 351 revenue villages. The low-lying Krishna-Godavari delta region in the central part of the AP coast would be the worst affected zone as 2205 km2 of its area including about 1593 km2 under various types of agricultural activities is lying within the future high tide limit of 2.5 m elevation.

Talakadu is a well known historic place situated on bank of the river Cauvery in Mysore district of Karnataka. The place is close to concave side of a prominent meander where large amount of sand has accumulated. It is believed that after construction of a reservoir upstream, sand was exposed to wind action burying the structures of Ganga dynasty and other later kingdoms. A number of buried sites have been identified by archaeological excavations conducted so far. Presently the area forms sand dunes with thick plantation cover. Analysis of RADAR data (fine beam RADARSAT and ENVISAT ASAR) led to identifying a hitherto unknown buried channel through the Old Talakadu town adjoining the excavated archaeological sites. The study suggests that RADAR penetration through the plantation canopy seems to have occurred as observed by comparing with corresponding optical data of LISS-IV. Below the canopy, sand and shrubs on top of the channel (topographically low area) are acting as smooth surface providing dark tone on radar imagery. During field validation GPS was extensively used to navigate through the forest canopy and locate the buried channel, excavated archaeological sites as well as other anomalous patterns. Synergistic application of optical (RESOURCESAT-1 LISS-IV and CARTOSAT-1 & 2) and radar (fine beam RADARSAT and ENVISAT ASAR) data led to identifying remote sensing based guides for archaeological exploration. Integration of known archaeological sites with the identified anomalous patterns was done in GIS environment. This study adds on to the knowledge base of the site and compliments already known information and suggested new areas for further archaeological exploration.

The coastal zones around the world are very densely populated and hence heavily packed with related infrastructures. So, the territorial nations have obvious apprehensions against the IPCC SRES (Intergovernmental Panel on Climate Change, Special Report on Emission Scenario) predicted sea level rise, as it would cause flooding of the low lying coasts and also other related chains of environmental endangers. This has driven these nations to initiate research studies in multiple directions for scientifically evaluating the phenomenon and impacts of sea level rise using all possible technologies including the Geomatics which possesses unique credentials in geosystem mapping. But certain advanced virtues available with Geomatics technology are yet to be capitalized deservingly in this. In addition, almost all the earlier studies have focused only on the impacts of sea level rise (SLR) and not on the predicted shift of high tide line (HTL) and the related inter tidal activities, which would cause a series of environmental disaster. Hence, the present research study was undertaken in a test site of 750 km2 in central Tamil Nadu coast to visualize the areas prone to submergence due to predicted SLR and areas prone to environmental disasters/degradation viz. erosion, deposition, salination of agricultural lands, pollution of aquifers, etc. due to predicted shift of HTL, using digital elevation models derived from SRTM data (Shuttle Radar Topographic Mission), geomorphology and land use/cover maps interpreted using IRS P6 LISS IV satellite data. The paper narrates the certain newer concepts and methodologies adopted in the study and the results.