Conservation of biodiversity of the coastal resources of Sundarbans,Northeast India: an integrated approach through environmental education     

Sarkar SK  Bhattacharya AK 《Marine pollution bulletin》2003,47(1-6):260-264

The Indian Sundarbans, a diversified coastal wetland on the southern fringe of the State of West Bengal, harbors a luxuriant biodiversity and acts as a potential refuge of living marine resources. Girdled with thick mangrove foliage, this estuarine delta system offers an excellent nursery ground for most of the brackishwater finfish and shellfish. Since supply of hatchery-produced tiger prawn seed (Penaeus monodon) is highly inadequate in West Bengal, the aquaculture farms of this region largely depend on the supply from natural resources. Being motivated by a regular cash income, the majority of coastal people from Sundarbans have adopted prawn seed collection as their profession almost throughout the year as an important source of earning. The users are neither trained nor guided at any stage from collection to marketing and are fully dependent on traditional methods. They first sort out the tiger prawn seeds (mainly the postlarval stage PL 20) accounting only 0.25-0.27% of the total catch and thereafter the major portion of the haul are thrown away on the beach flats or the tidal mudflats. This wasted by-catch contains the juveniles of economic and uneconomic varieties of finfish and shellfish along with a bulk of holoplankters and meroplankters (non-target species). This practice causes several ecological and occupational consequences, namely, (i) the huge destruction of the pelagic biota that can lead to severe stock depletion as well as hamper the energy transference through the marine ecosystem food webs; (ii) constant dragging of nets along the coast and tidal creeks paves the way for soil erosion, uprooting the mangrove seedlings and saltmarsh vegetation; (iii) the water quality is deteriorating in the catchment areas due to mud erosion and (iv) due to constant contact with the seawater, the collectors are affected with waterborne diseases, skin infections, reproductive tract disease in women and many other contagious diseases.This paper, in addition to identifying the challenge to environmental quality and resource abundance, emphasizes the need for grass-root public education so that local people come to understand, support and implement sustainable resource conservation and environmental protection activities now and in the future. As a follow-up course of action, the authors have initiated a general awareness program for developing consciousness among the coastal people regarding proper use of natural resources. Initiatives are taken for educating coastal people by holding workshops and seminars with the use of educational resource materials. Exclusive awareness camps and grass root level training for coastal people are also being proposed as a future course of action by means of exhibitions, audiovisuals etc. It is proposed that local government bodies come forward to mitigate this problem with scientific and rational approaches and to take proper actions towards conservation.  相似文献   

Facies, dissolution seams and stable isotope compositions of the Rohtas Limestone (Vindhyan Supergroup) in the Son valley area, central India     

S. Banerjee  S. K. Bhattacharya  S. Sarkar 《Journal of Earth System Science》2005,114(1):87-96

The early Mesoproterozoic Rohtas Limestone in the Son valley area of central India represents an overall shallowing-upward carbonate succession. Detailed facies analysis of the limestone reveals outer- to inner-shelf deposition in an open marine setting. Wave-ripples, hummocky cross stratifications and edgewise conglomerates argue against a deep marine depositional model for the Rohtas Limestone proposed earlier. Stable isotope analysis of the limestone shows that δ¹³C and δ¹⁸O values are compatible with the early Mesoproterozoic open seawater composition. The ribbon limestone facies in the Rohtas Limestone is characterized by micritic beds, each decoupled in a lower band enriched and an upper band depleted in dissolution seams. Band-wise isotopic analysis reveals systematic short-term variations. Comparative enrichment of the heavier isotopes in the upper bands is attributed to early cementation from sea water and water derived from the lower band undergoing dissolution because of lowering of pH at depth. The short-term positive shifts in isotopic compositions in almost every upward gradational transition from a seamed band to a non-seamed band support the contention that dissolution seams here are of early diagenetic origin, although their formation was accentuated under overburden pressure.  相似文献   

An approach for GIS-based statistical landslide susceptibility zonation—with a case study in the Himalayas   总被引：14，自引：1，他引：14  

Ashis K. Saha  Ravi P. Gupta  Irene Sarkar  Manoj K. Arora  Elmar Csaplovics 《Landslides》2005,2(1):61-69

Landslide susceptibility zonation (LSZ) is necessary for disaster management and planning development activities in mountainous regions. A number of methods, viz. landslide distribution, qualitative, statistical and distribution-free analyses have been used for the LSZ studies and they are again briefly reviewed here. In this work, two methods, the Information Value (InfoVal) and the Landslide Nominal Susceptibility Factor (LNSF) methods that are based on bivariate statistical analysis have been applied for LSZ mapping in a part of the Himalayas. Relevant thematic maps representing various factors (e.g., slope, aspect, relative relief, lithology, buffer zones along thrusts, faults and lineaments, drainage density and landcover) that are related to landslide activity, have been generated using remote sensing and GIS techniques. The LSZ derived from the LNSF method, has been compared with that produced from the InfoVal method and the result shows a more realistic LSZ map from the LNSF method which appears to conform to the heterogeneity of the terrain.  相似文献   

A note on the lithosphere thickness and heat flow density of the Indian Craton from MAGSAT data     

Ranjit Kumar Sarkar  Dilip Kumar Saha 《Acta Geophysica》2006,54(2):198-204

The Curie depth map of India compiled from MAGSAT data has been used for preparing the lithosphere thickness and the surface heat flow density maps of the Indian Craton, utilizing the concept of magnetothermometry. The lithosphere thicknesses of the major Indian geological units/provinces, as obtained from the prepared map, are found to be in reasonably good agreement with the previously published values for these regions. Also, the surface heat flow density values obtained from the prepared maps closely follow the previously published results. The maps are useful in providing first order estimates of lithosphere thickness and surface heat flow density of the important geological units/provinces of India.  相似文献   

Auto-correlation analysis of wave heights in the Bay of Bengal   总被引：1，自引：0，他引：1  

Abhijit Sarkar  Jignesh Kshatriya  K. Satheesan 《Journal of Earth System Science》2006,115(2):235-237

Time series observations of significant wave heights in the Bay of Bengal were subjected to auto-correlation analysis to determine temporal variability scale. The analysis indicates an exponential fall of auto-correlation in the first few hours with a decorrelation time scale of about six hours. A similar figure was found earlier for ocean surface winds. The nature of variation of auto-correlation with time lags was also found to be similar for winds and wave heights  相似文献   

Soil resource appraisal towards land use planning using satellite remote sensing and gis a case study in patloinala micro-watershed, district puruliya, west bengal     

Dipak Sarkar  S. K. Gangopadhyay  A. K. Sahoo 《Journal of the Indian Society of Remote Sensing》2006,34(3):245-260

Visual interpretation of IRS ID LISS-III fused with PAN data (1:12,500 scale) ofPatloinala micro-watershed of Puruliya district, West Bengal was carried out for delineating the physiographic units based on the variations in image characteristics. The major physiographic units identified were upland(Tanr), medium land(Baid), and low land(Bahal andKanali). The satellite remote sensing data coupled with ground truth were translated in terms of soils using composite interpretation map as base. The abstraction level attained was phases of soil series based on Soil Taxonomy. On the basis of physiographic variation and soil or soil site characteristics such as texture, depth, slope, erosion etc. the problem areas were identified and land use plan has been suggested for the overall development of the micro-watershed.  相似文献   

Numerical study of the effects of urban heat island on the characteristic features of the sea breeze circulation     

Abhijit Sarkar  R. S. Saraswat  A. Chandrasekar 《Journal of Earth System Science》1998,107(2):127-137

A two-dimensional numerical model is employed to study the effect of the coastal urban heat island on the sea breeze front and the thermal internal boundary layer height. The temperature at the land surface is determined by solving an energy budget equation. The effect of the urban heat island is studied by varying the width of the region and its intensity. During the early afternoon, the presence of the urban heat island enhances the strength of convergence of the sea breeze front and also reduces its inland penetration. The presence of the urban heat island causes increased thermal internal boundary layer height. Larger urban width causes larger vertical velocity and higher thermal internal boundary layer. Stronger convergence and higher thermal internal boundary layer are also obtained in case of larger heat island intensity.  相似文献   

Nature, origin and evolution of the granitoid-hosted early Proterozoic copper-molybdenum mineralization at Malanjkhand, Central India – a reply     

S. C. Sarkar  S. Kabiraj  S. Bhattacharya  A. B. Pal 《Mineralium Deposita》1997,32(6):622-622

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Methane emissions from rice fields amended with biogas slurry and farm yard manure     

Goutam Debnath  M. C. Jain  Sushil Kumar  K. Sarkar  Suresh K. Sinha 《Climatic change》1996,33(1):97-109

In an experiment on methane-emission measurements from rice fields amended with urea, biogas spent slurry (BSS) + urea, and farm yard manure (FYM) + urea, three distinctive peaks in the methane emissions were observed at 15, 46, and 69 days after transplanting (DAT) due to the availability of readily degradable C-sources. In all cases, the highest peak was at 69 DAT. The steepest Eh drop to a minimum of -320 mV was reached within two weeks of submergence. pH ranged between 7.5 and 8.5. The combined fertilization (FYM + urea) plot showed the maximum emission rate of 4.86 mg m^–2 h^–1 with a total load of 49.44 kg ha^–1 and was 2.3 times higher than (BSS + urea)-treated plot (22.08 kg ha^–1). Grain yields in urea, (BSS + urea) and (FYM + urea) plots were 3.34, 2.94, and 2.85 t ha^–1 respectively, suggesting that biogas slurry is a preferred source over FYM causing lesser environmental pollution without any significant reduction in grain yield.  相似文献   

Selection of optimum frequency of a wind scatterometer     

Abhijit Sarkar  Raj Kumar  Mannil Mohan 《Journal of Earth System Science》1988,97(2):192-192

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