WISE USE OF WETLAND FOR SUSTAINABLE LIVELIHOOD THROUGH PARTICIPATORY APPROACH： A CASE OF ADAPTING TO CLIMATE CHANGE     

Haq A H M Rezaul　Tapan Kumar Ghosal　Pritam Ghosh　M Aminul Islam 《湿地科学》2005,3(3):161-166

1INTRODUCTION Hydroponics(aGreekword,hydromeanswater andponos,labour),asoil-lessagriculture,isa termtobedescribedinseveralwaysinwhichplants cangrowwithoutsoil,byuseofaninertmedium whereplantcantakeupessentialnutrients,either fromwaterinwhichanutrientsolutionisaddedor fromorganicmaterialsthatexistsinthemedium.Thesemediacanbegravel,sand,peat,vermiculate,prelite,sawdustorotherplantmatters(organiccom ponents).Therefore,theprocessinwhichaquatic weedsaredumpedonwatertoconstructfloatingbed orart…  相似文献   

Overrunning of shelf water in the southern Mid-Atlantic Bight     

Ajoy Kumar  A. Valle-Levinson  L.P. Atkinson 《Progress in Oceanography》2006,70(2-4):213

Analyses of two years (1992 and 1993) of high-resolution sea surface temperature satellite images of the southern Mid Atlantic Bight (MAB), showed that unusually extensive overhang of shelf water occurs episodically, and coherently over along shelf distances of several 100 km. These episodes are dubbed overrunning of the Slope Sea by shelf water. The overrunning volume has a “face” and a “back” (southern and northern limit). It transports substantial quantities of shelf water southward, and does not retreat onto the shelf, but eventually joins the western edge of the Gulf Stream in the vicinity of Chesapeake Bay. The combined analyses of satellite imagery and various in situ data further demonstrated that the shelf waters overrunning the Slope Sea were not mere surface features but reached depths between 40 and 60 m. Results confirm previous concepts on shelf circulation, shelf–slope exchange and fate of shelf water. They also shed new light on shelf water budget: overrunning of the Slope Sea and southwest transport by upper slope current constitutes an important conduit for shelf water transport. Winter storms move the shelf–slope front, and with it shelf water, offshore to distances 10–40 km. The offshore displacement of shelf water can be related to the onshore veering of the Gulf Stream near Cape Hatteras, producing a blocking effect on the shelf circulation. Such a blocking effect of the southwestward flow of shelf water in the MAB appeared to be the reason for the overrunning of shelf water off New Jersey. In addition, the excess fresh water discharge from the St. Lawerence was also observed to be related to the overflow of shelf water off New Jersey.  相似文献   

Fluid Institutions: Commons in Transition in the Periurban Interface     

Aditya Kumar Singh  Vishal Narain 《社会与自然资源》2019,32(5):606-615

Amidst growing concern about the decline of the commons, this case underscores the importance of understanding how the commons are refashioned and remade to address emerging challenges in periurban spaces. This article describes how institutions surrounding the use of common property resources get transformed and evolve in periurban contexts. What were once johads – common property village ponds – undergo a change in their usage from storing rainwater to storing waste water of the city for irrigation. This emerges as a collective response to the uncertainty attached to the availability of waste water. New institutions evolve with regard to contributions to waste water infrastructure, as well as the appropriation of waste water. Further research should document the changing use of village commons and the emergence of new institutions governing them.  相似文献   

An assessment of the impact of urbanization and land use changes in the fast-growing cities of Saudi Arabia     

Abdullah F. Alqurashi  Lalit Kumar 《国际地球制图》2019,34(1):78-97

Understanding rates, patterns and types of land use and land cover (LULC) changes are essential for various decision-making processes. This study quantified LULC changes and the effect of urban expansion in three Saudi Arabian cities: Riyadh, Jeddah and Makkah using Landsat images of 1985, 2000 and 2014. Seasonal change of vegetation cover was conducted using normalised difference vegetation index, and object-based image analysis was used to classify the LULC changes. The overall accuracies of the classified maps ranged from 84 to 95%, which indicated sufficiently robust results. Urban area was the most changed land cover, and most of the converted land to urban was from bare soil. The seasonal analysis showed that the change of vegetation cover was not constant due to climatic conditions in these areas. The agricultural lands were significantly decreased between 1985 and 2014, and most of these lands were changed to bare soil due to dwindling groundwater resources.  相似文献   

Discrimination and classification of mangrove forests using EO-1 Hyperion data: a case study of Indian Sundarbans     

Tanumi Kumar  Abhishek Mandal  Dibyendu Dutta  R. Nagaraja  Vinay Kumar Dadhwal 《国际地球制图》2019,34(4):415-442

In remote sensing the identification accuracy of mangroves is greatly influenced by terrestrial vegetation. This paper deals with the use of specific vegetation indices for extracting mangrove forests using Earth Observing-1 Hyperion image over a portion of Indian Sundarbans, followed by classification of mangroves into floristic composition classes. Five vegetation indices (three new and two published), namely Mangrove Probability Vegetation Index, Normalized Difference Wetland Vegetation Index, Shortwave Infrared Absorption Index, Normalized Difference Infrared Index and Atmospherically Corrected Vegetation Index were used in decision tree algorithm to develop the mangrove mask. Then, three full-pixel classifiers, namely Minimum Distance, Spectral Angle Mapper and Support Vector Machine (SVM) were evaluated on the data within the mask. SVM performed better than the other two classifiers with an overall precision of 99.08%. The methodology presented here may be applied in different mangrove areas for producing community zonation maps at finer levels.  相似文献   

Assessment of glacier stored water in Karakoram Himalaya using satellite remote sensing and field investigation     

Kamal Kant SINGH  Harendra Singh NEGI  Dhiraj Kumar SINGH 《山地科学学报》2019,(4)

Karakoram Himalaya(KH) has continental climatic conditions and possesses largest concentration of glaciers outside the polar regions. The melt water from these glaciers is a major contributor to the Indus river. In this study, various methods have been used to estimate the ice volume in the Karakoram Range of glaciers such as Coregistration of Optically Sensed Images and Correlation(COSI-Corr) method and Area-Volume relations. Landsat 8 satellite data has been used to generate the ice displacement, velocity and thickness map. Our study for 558 Karakoram glaciers revealed that the average ice thickness in Karakoram is 90 m. Ground Penetrating Radar(GPR) survey has been conducted in one of the KH glacier i.e. Saser La glacier and the collected GPR data is used for the validation of satellite derived thickness map. GPR measured glacier thickness values are found comparable with satellite estimated values with RMSE of 4.3 m. The total ice volume of the Karakoram glaciers is estimated to be 1607±19 km3(1473±17 Gt), which is equivalent to 1473±17 km3 of water equivalent. Present study also covers the analysis of glacier surface displacement, velocity and ice thickness values with reference to glacier mean slope.  相似文献   

Modelling Chorabari Lake outburst flood,Kedarnath, India     

Mohammd RAFIQ  Shakil Ahmad ROMSHOO  Anoop Kumar MISHRA  Faizan JALAL 《山地科学学报》2019,(1):64-76

In this study, the Glacier Lake Outburst Flood(GLOF) that occurred over Kedarnath in June 2013 was modeled using integrated observations from the field and Remote Sensing(RS). The lake breach parameters such as area, depth, breach, and height have been estimated from the field observations and Remote Sensing(RS) data. A number of modelling approaches, including Snow Melt Runoff Model(SRM), Modified Single Flow model(MSF), Watershed Management System(WMS), Simplified Dam Breach Model(SMPDBK) and BREACH were used to model the GLOF. Estimations from SRM produced a runoff of about 22.7 m3 during 16–17, June 2013 over Chorabari Lake. Bathymetry data reported that the lake got filled to its maximum capacity(3822.7 m3) due to excess discharge. Hydrograph obtained from the BREACH model revealed a peak discharge of about 1699 m3/s during an intense water flow episode that lasted for 10–15 minutes on 17 th June 2013. Excess discharge from heavy rainfall and snowmelt into the lake increased its hydrostatic pressure and the lake breached cataclysmically.  相似文献   

Shock‐thermal history of the Agoudal (IIAB) iron meteorite from microstructural studies     

D. Ray  S. Ghosh  H. Chennaoui Aoudjehane  S. Das 《Meteoritics & planetary science》2019,54(12):3082-3088

The Agoudal IIAB iron meteorite exhibits only kamacite grains (~6 mm across) without any taenite. The kamacite is homogeneously enriched with numerous rhabdite inclusions of different size, shape, and composition. In some kamacite domains, this appears frosty due to micron‐scale rhabdite inclusions (~5 to 100 μm) of moderate to high Ni content (~26 to 40 wt%). In addition, all the kamacite grains in matrix are marked with a prominent linear crack formed during an atmospheric break‐up event and subsequently oxidized. This feature, also defined by trails of lowest Ni‐bearing (mean Ni: 23 wt%) mm‐scale rhabdite plates (fractured and oxidized) could be a trace of a pre‐existing γ–α interface. Agoudal experienced a very slow rate of primary cooling ~4 °C Ma^?1 estimated from the binary plots of true rhabdite width against corresponding Ni wt% and the computed cooling rate curves after Randich and Goldstein (1978). Chemically, Agoudal iron (Ga: 54 ppm; Ge: 140 ppm; Ir: 0.03 ppm) resembles the Ainsworth iron, the coarsest octahedrite of the IIAB group. Agoudal contains multiple sets of Neumann bands that are formed in space and time at different scales and densities due to multiple impacts with shock magnitude up to 130 kb. Signatures of recrystallization due to postshock low temperature mild reheating at about 400 °C are also locally present.  相似文献   

Zooplankton Distribution in Coastal Water off Gopalpur,North-Western Bay of Bengal     

S. K. Baliarsingh  Suchismita Srichandan  Aneesh A. Lotliker  T. Srinivasa Kumar  K. C. Sahu 《中国海洋大学学报(英文版)》2018,17(4):879-889

An interannual study on zooplankton abundance, biomass, and species composition was carried out during different seasons in two local coastal water types off Gopalpur, north-western Bay of Bengal. Although, Type-1 was observed with higher zooplankton abundance in comparison to Type-2, pattern of variation followed similar seasonal trends in both water types during individual years. Well pronounced seasonality was observed in zooplankton distribution. Zooplankton community was composed of 217 holoplankton and 22 meroplankton. The holoplankton community was predominated by copepod in terms of species diversity and abundance followed by hydrozoa, tintinnida, malacostraca, gastropoda, chaetognatha and chordata. The meroplankton were represented by larval forms viz. bivalve veliger, brachyuran zoea larvae, caridean larvae, copepod nauplii, fish egg and gastropod veliger. Dominance of copepod species viz. Acrocalanus longicornis, Paracalanus aculeatus and Paracalanus parvus were observed frequently in both water types. The species richness was higher in Type-1 in comparison to Type-2 during both the years. Salinity regimes and availability of phytoplankton prey influenced the distribution and species composition of zooplankton assemblage.  相似文献   

Deposition of atmospheric pollutant and their chemical characterization in snow pit profile at Dokriani Glacier,Central Himalaya     

Shipika Sundriyal  Tanuj Shukla  Lekhendra Tripathee  Dwarika Prashad Dobhal  Sameer Kumar Tiwari  Uday Bhan 《山地科学学报》2018,15(10):2236-2246

The uncertainty in assessing the numerous atmospheric pollutants transported via wind from arid and semi-arid regions is affecting the glacial ecosystem. In our study area due to the complexity of the system, a prominent seasonal difference noticed among major ions(Ca~(2+), Mg~(2+), SO_4~(2-), and NO_3~-). There is a need for understanding the ions cycling as a whole and the directionality of the feedback loops in the system. Therefore, we provide an appraisal of our current hypothesis for seasonal difference in major ion concentration from snow samples for two corresponding years(2013 and 2015) at Dokriani Glacier. A systematic study of chemical compositionsin the shallow snow pit from Dokriani Glacier was undertaken for the pre-monsoon season to understand the cycling of major ions from atmosphere to solute acquisition process. The intimating connections of ions cycling in snow and its temporal behavior was observed and analyzed through various statistical tests. Among major ions, the SO_4~(2-)has the highest concentration among anions on an average considered as 14.21% in 2013 and 29.46% in 2015. On the other side Ca~(2+) is the dominant cation contributing 28.22% in 2013 and 15.3% in 2015 on average. The average ratio of Na+/Cl-was higher in 2013 whereas lower in 2015. The backward trajectory analysis suggests the possible sources of the ions transported from Central Asia through the Western Disturbance(WD) as a prominent source of winter precipitation mainly in the Central Himalaya. Ionicconcentration of Ca~(2+) in cations was highly dominated while in anion SO_4~(2-)played the major role. Factor analysis and correlation matrix suggested that, the precipitation chemistry is mostly influenced by anthropogenic, crustal, and sea salt sources over the studied region. The elemental cycling through ocean, atmosphere and biosphere opens up new ways to understand the geochemical processes operating at the glacierized catchments of the Himalaya. Moreover, increasing the field-based studies in the coming decades would also have the certain advantage in overcoming the conceptual and computational geochemical modelling difficulties.  相似文献