Browsing by Author "C.S. Jha"

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A Step Towards Improvements in the Characteristics of Self Excited Induction Generator
(1993) L. Shridhar; Bhim Singh; C.S. Jha; Vice Chancellor
Given due consideration to the increasing use of Self Excited Induction Generators (SEIGs) in isolated power plants, an attempt is made to effect suitable design modifications in standard induction motor to improve its performance as SEIG. This paper explores the theory behind such improvements and sets the concept of voltage regulation in SEIG. Typical results of the sensitivity studies performed are presented and inferences are drawn to suggest guidelines for real design problem of such generators. © 1992 IEEE
Application of landscape ecology and remote sensing for assessment, monitoring and conservation of biodiversity
(2010) J.S. Singh; P.S. Roy; M.S.R. Murthy; C.S. Jha
Landscape ecology, inter alia, addresses the question as to how altered landscape patterns affect the distribution, persistence, and abundance of a species. Landscape ecology plays an important role in integrating the different scales of biodiversity from habitat patch to biome level. Satellite remote sensing technology with multi-sensor capabilities offers multi-scale information on landscape composition and configuration. Advances in geospatial analytical tools and spatial statistics have improved the capability to quantify spatial heterogeneity. Globally, landscape level characterization of biodiversity has become an important discipline of science. Considering the vast extent, heterogeneity, and ecological and economic importance of forest landscapes, significant efforts have been made in India during the past decade to strengthen landscape level biodiversity characterization. The generic frame work of studies comprises preparation of national databases providing information on composition and configuration of different landscapes using multi-scale remote sensing techniques, understanding the landscape patterns using geospatial models to elicit disturbance and diversity patterns and application of this information for bioprospecting and conservation purposes. Studies on hierarchical linkage of multi-scale information to study the processes of change, landscape function, dynamics of habitat fragmentation, invasion, development of network of conservation areas based on the understanding of multi-species responses to landscape mosaics, macro-ecological studies to understand environment and species richness, habitat and species transitions and losses, landscape level solutions to adaptation and mitigation strategies to climate change are a few of the future challenges. The paper presents the current experiences and, analyses in conjunction with international scenario and identifies future challenges of Indian landscape level biodiversity studies. © 2010 Indian Society of Remote Sensing.
Forest fragmentation and its impact on species diversity: An analysis using remote sensing and GIS
(2005) C.S. Jha; Laxmi Goparaju; Anshuman Tripathi; Biswadeep Gharai; A.S. Raghubanshi; J.S. Singh
The process of forest fragmentation, a common phenomenon occurring in tropical forests, not only results into continuously forest getting fragmented but also brings about several physical and biological changes in the environment of forests. Consequently, there is a loss of biodiversity due to change in habitat conditions. These remnant fragments provide the last hope for biodiversity conservation. The present study deals with the impact of decreasing patch size of a fragmented forest on the diversity of the tropical dry deciduous forests in Vindhyan highlands, India. There is considerable change in the vegetation cover of this region owing to rapid industrialization and urbanization, which has also contributed to forest fragmentation. In the present study, remotely sensed data has been used to describe the changes brought about in vegetated areas over a period of 10 years as a result of fragmentation and its impact on biodiversity was assessed. Further, in order to assess the loss of species with respect to the reduction in patch size, species area curves for various change areas were analysed. It was observed that the rate of decrease in the number of species is faster in the case of negative change areas as compared to the positive change areas of the region. Various diversity indices also support this observation. Such an analysis would help in formulating appropriate conservation measures for the region. © Springer 2005.
Forest fragmentation impacts on phytodiversity - An analysis using remote sensing and GIS
(2005) Laxmi Goparaju; Anshuman Tripathi; C.S. Jha
The present study deals with the forest fragmentation of Vindhyan highlands in the Indian dry tropical forests. The fragmentation scenario has been quantified using remote sensing data and GIS techniques. The remotely sensed data-derived vegetation map was an input to the fragmentation analysis. Transects were laid to inventory along different forest patch sizes of various communities to study the biodiversity levels. It was observed that with changing fragment, there is change in biodiversity levels. Hence, patch size might play an important role in the regulation of biodiversity levels. This information may provide an insight into the conservation strategy formulation for the fragmented dry tropical area. The analysis has brought out that biodiversity levels are different in various fragments of different sizes. Small fragments are similar to each other in terms of species composition; similar is the case with large fragments in general. It was also found that the small and large fragments are dissimilar in terms of species composition. The diversity levels among the fragments of similar size class varied across the anthropogenic gradient. Analysis of species richness, diversity indices has helped in studying the patterns/levels of biodiversity in different fragment size classes along different levels of anthropogenic pressure. The merits of conserving the small and large fragments have been discussed.
New vegetation type map of India prepared using satellite remote sensing: Comparison with global vegetation maps and utilities
(Elsevier B.V., 2015) P.S. Roy; M.D. Behera; M.S.R. Murthy; Arijit Roy; Sarnam Singh; S.P.S. Kushwaha; C.S. Jha; S. Sudhakar; P.K. Joshi; Ch. Sudhakar Reddy; Stutee Gupta; Girish Pujar; C.B.S. Dutt; V.K. Srivastava; M.C. Porwal; Poonam Tripathi; J.S. Singh; Vishwas Chitale; A.K. Skidmore; G. Rajshekhar; Deepak Kushwaha; Harish Karnatak; Sameer Saran; A. Giriraj; Hitendra Padalia; Manish Kale; Subrato Nandy; C. Jeganathan; C.P. Singh; C.M. Biradar; Chiranjibi Pattanaik; D.K. Singh; G.M. Devagiri; Gautam Talukdar; Rabindra K. Panigrahy; Harnam Singh; J.R. Sharma; K. Haridasan; Shivam Trivedi; K.P. Singh; L. Kannan; M. Daniel; M.K. Misra; Madhura Niphadkar; Nidhi Nagabhatla; Nupoor Prasad; O.P. Tripathi; P. Rama Chandra Prasad; Pushpa Dash; Qamer Qureshi; S.K. Tripathi; B.R. Ramesh; Balakrishnan Gowda; Sanjay Tomar; Shakil Romshoo; Shilpa Giriraj; Shirish A. Ravan; Soumit Kumar Behera; Subrato Paul; Ashesh Kumar Das; B.K. Ranganath; T.P. Singh; T.R. Sahu; Uma Shankar; A.R.R. Menon; Gaurav Srivastava; Neeti; Subrat Sharma; U.B. Mohapatra; Ashok Peddi; Humayun Rashid; Irfan Salroo; P. Hari Krishna; P.K. Hajra; A.O. Vergheese; Shafique Matin; Swapnil A. Chaudhary; Sonali Ghosh; Udaya Lakshmi; Deepshikha Rawat; Kalpana Ambastha; Akhtar H. Malik; B.S.S. Devi; K.C. Sharma; Prashant Mukharjee; Ajay Sharma; Priya Davidar; R.R. Venkata Raju; S.S. Katewa; Shashi Kant; Vatsavaya S. Raju; B.P. Uniyal; Bijan Debnath; D.K. Rout; Rajesh Thapa; Shijo Joseph; Pradeep Chhetri; Reshma M. Ramachandran
A seamless vegetation type map of India (scale 1: 50,000) prepared using medium-resolution IRS LISS-III images is presented. The map was created using an on-screen visual interpretation technique and has an accuracy of 90%, as assessed using 15,565 ground control points. India has hitherto been using potential vegetation/forest type map prepared by Champion and Seth in 1968. We characterized and mapped further the vegetation type distribution in the country in terms of occurrence and distribution, area occupancy, percentage of protected area (PA) covered by each vegetation type, range of elevation, mean annual temperature and precipitation over the past 100 years. A remote sensing-amenable hierarchical classification scheme that accommodates natural and semi-natural systems was conceptualized, and the natural vegetation was classified into forests, scrub/shrub lands and grasslands on the basis of extent of vegetation cover. We discuss the distribution and potential utility of the vegetation type map in a broad range of ecological, climatic and conservation applications from global, national and local perspectives. Weused 15,565 ground control points to assess the accuracy of products available globally (i.e., GlobCover, Holdridge's life zone map and potential natural vegetation (PNV) maps). Hence we recommend that the map prepared herein be used widely. This vegetation type map is the most comprehensive one developed for India so far. It was prepared using 23.5m seasonal satellite remote sensing data, field samples and information relating to the biogeography, climate and soil. The digital map is now available through a web portal (http://bis.iirs.gov.in). © 2015 Elsevier B.V.