An evaluation of progress in implementing ecosystem-based management of fisheries in 33 countries   总被引：1，自引：0，他引：1  

Tony J. Pitcher  Daniela Kalikoski  Katherine Short  Divya Varkey  Ganapathiraju Pramod 《Marine Policy》2009

The performance of 33 countries was evaluated for ecosystem-based management (EBM) of fisheries in three fields (principles, criteria and implementation) using quantitative ordination including uncertainty. No country rated overall as ‘good’, only four countries were ‘adequate’, while over half received ‘fail’ grades. A few developing countries performed better than many developed nations. Two case studies test the method. In Indonesia, Raja Ampat and Papua, rated similar to the national evaluation, but better performance might follow successful implementation of a planned EBM initiative. A workshop in Australia rated regional fisheries managed by New South Wales 20% lower for EBM than federally managed fisheries.  相似文献   

Matter(s) in social and cultural geography     

Ben Anderson  Divya Tolia-Kelly   《Geoforum》2004,35(6):669-674

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Chronology of major terrace forming events in the Andaman islands during the last 40 kyr     

Neeraj Awasthi  Jyotiranjan S. Ray  Amzad H. Laskar  Madhusudan G. Yadava 《Journal of the Geological Society of India》2013,82(1):59-66

Major earthquakes that trigger tsunamis are great natural hazards. The devastations caused by the December 26, 2004 Sumatran earthquake, and the March 11, 2011 Japan earthquake, and associated tsunamis will remain in our memories for a long time. Such events reaffirm the need for studying the cause and effects of large earthquakes of the past and to prepare the world better for the future. In such an effort, to understand the pattern of earthquakes and their effects on the geomorphic evolution, we have studied deformation history in the Andaman and Nicobar Islands, located in one of the most active convergent margins of the world. Focusing on tectonically formed coastal terraces and determining the timing of their formation from the exposed dead corals, we have been able to reconstruct the history of major earthquakes in these islands for the last 40 kyr. Our results in conjunction with the existing radiocarbon age data from coastal terraces of these islands appear to suggest that the frequency of major earthquakes (M > 7) in the region has increased during the last 9 kyr. In confirmation with some earlier work, we find evidences for a major earthquake and a tsunami between 500-600 cal yr BP and possibly 4 others during 6–9 cal kyr BP. Our results also indicate that there has been a continuous subsidence of the south Andaman Islands.  相似文献   

Major ash eruptions of Barren Island volcano (Andaman Sea) during the past 72 kyr: clues from a sediment core record     

Neeraj Awasthi  Jyotiranjan S. Ray  Amzad H. Laskar  Alok Kumar  M. Sudhakar  Rajneesh Bhutani  Hetu C. Sheth  Madhusudan G. Yadava 《Bulletin of Volcanology》2010,72(9):1131-1136

Barren Island (Andaman Sea) is the northernmost active volcano of the Indonesian Arc. To construct the eruptive history of this little studied volcano, we measured ¹⁴C dates of inorganic carbon in sediment beds, and Sr and Nd isotopic ratios of seven discrete ash layers, in a marine sediment core collected from 32 km southeast of the volcano. The study reveals that the volcano had seven major ash eruptions at ~70, 69, 61, 24, 19, 15, and 10 ka. The ash layers erupted from 70 ka through 19 ka have highly uniform Nd isotopic composition, and since the ~15 ka eruption to the present the isotopic composition has been highly variable. Between ~24 ka and ~10 ka, the volcano had large ash eruptions spaced at 4,500 year intervals. Isotopically correlating the precaldera lavas and ash exposed on the volcano to the uppermost ash layer in the core, we infer that the caldera of Barren Island volcano is younger than 10 ka.  相似文献   

Groundwater resources assessment of the Koyna River basin,India   总被引：2，自引：1，他引：1  

Pradeep?K.?NaikEmail author  Arun?K.?Awasthi 《Hydrogeology Journal》2003,11(5):582-594

The Western Ghats (hills) region of the Indian peninsula in western India receives heavy precipitation (4,000–6,000 mm/year), but the headwater basins that coalesce runoff from these hills retain very small quantities of water due to the steep topography. However, the narrow valleys in these hills support agriculture based on surface water irrigation, and several medium to large irrigation projects have already been constructed with well-defined canal networks. These developments have boosted agricultural productivity in the region, but at the same time they are causing an economic disparity between the command areas (irrigated by these canals) and non-command areas. Water-logging problems are also occurring in low-lying areas. While these problems are mainly due to poor groundwater management strategies in the region, the groundwater resources in these headwater basins should be properly assessed and suitable measures taken for uniform groundwater development. As a first step in this direction, groundwater resources have been assessed as a case study for the lower Koyna River basin, a head water basin on the east of the main ridge of the Western Ghats.Regional specific yield (0.012) and groundwater recharge have been estimated on the basis of water table fluctuation method. Groundwater recharge amounting to 57 MCM (million m³) in a year takes place in the region through vertical percolation of rainwater (31 MCM), return flow of water applied for irrigation (23 MCM), and recharge due to surface water tanks (3 MCM). Recharge to deeper aquifers has been estimated at 1 MCM during dry seasons (November–May). Safe yield has been estimated at 58 MCM annually which includes the present groundwater draft by wells for domestic, stock, and irrigational needs estimated at 16.50 MCM per year and the natural losses from the groundwater system which are mostly baseflow and spring discharges amounting to 38 MCM (35 MCM baseflow + 3 MCM spring flow) per year, out of which 7 MCM is already being directly pumped from the tributaries of the Koyna River for irrigational needs. Thus, there remains a balance of only 3.5 MCM of groundwater for further groundwater development. Assuming that at least 25% (7 MCM) of the unutilized baseflow (28 MCM) can be brought to fruitful use, about 10.5 MCM (7+3.5 MCM) of groundwater can be used in the existing hydrogeological environment through about 500 additional wells.

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Resumen La región de las montañas de Western Ghats, al Oeste de la Península India, registra elevados valores de precipitación (de 4.000 a 6.000 mm/a), pero las condiciones topográficas de dichas montañas no permiten la existencia de acuíferos de entidad suficiente para albergar volúmenes grandes de aguas subterráneas. Los valles estrechos de las montañas sí permiten el desarrollo de las aguas superficiales, de manea que se ha realizado varios proyectos medianos y grandes de riego mediante redes de canales bien definidas. Estos desarrollos han propiciado un aumento de la producción agrícola en la región, pero, a la vez, se ha agudizado las diferencias económicas entre las zonas regadas y las no regadas. Además, las depresiones topográficas están padeciendo problemas de inundación. Como estos problemas son principalmente debidos a estrategias deficientes de gestión de las aguas subterráneas, se recomienda que los recursos subterráneas de las cuencas de cabecera sean adecuadamente determinados, y que se adopte medidas apropiadas para desarrollarlos uniformemente. El primer paso ha consistido en determinar los recursos subterráneos de la cabecera del río Koynam, situada al Este de la Sierra principal de los Western Ghats. Se ha estimado todos los parámetros de recarga y descarga, así como los recursos renovables, en la cuenca del río Koyna ubicada aguas debajo de la presa de Koyna.

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Résumé La région des Collines occidentales (Western Ghats) de la péninsule indienne en Inde occidentale reçoit de fortes précipitations (4.000–6.000 mm/an); mais les bassins situés en tête qui convergent dans ces collines retiennent très peu d'eaux souterraines du fait des mauvaises conditions de pente en surface. Les vallées étroites dans ces collines offrent de larges espaces pour la mise en valeur des eaux de surface, en sorte que plusieurs projets d'irrigation moyens ou importants ont déjà été réalisés dans ces régions avec un réseau bien défini de canaux. Cette mise en valeur a réellement poussé la productivité agricole de la région, mais en même temps elle produit aussi une disparité économique entre les régions desservies (zones irriguées par ces canaux) et non desservies. Des problèmes relatifs à l'eau se posent également dans les zones basses. Alors que ces problèmes sont surtout dus à de médiocres stratégies de gestion dans la région, il est recommandé que les ressources en eaux souterraines dans ces bassins en tête soient correctement évaluées et que des mesures adéquates soient prises en vue d'une mise en valeur uniforme des eaux souterraines. À titre de première étape dans cette direction, les ressources en eaux souterraines ont été évaluées lors d'une étude de cas du bassin de la rivière Koyna, un bassin de tête situé à l'est de la chaîne principale des Collines Occidentales. Tous les paramètres d'entrée et de sortie ont été estimés et un bilan a été réalisé entre ces deux composantes. Les ressources statiques et dynamiques en eaux souterraines ont été estimées et un rendement sûr a été déterminé pour le bassin de la rivière Koyna en aval du barrage de Koyna.

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Springs in a headwater basin in the Deccan Trap country of the Western Ghats, India     

Pradeep K. Naik  Arun K. Awasthi  Prakash C. Mohan 《Hydrogeology Journal》2002,10(5):553-565

Available literature reveals that little work has been done on the origin of springs in a basaltic terrain. Close examination of such springs in about 2,000 km² of the upper Koyna River basin in the Deccan Trap country of the Western Ghats (hills), India, reveals that their origins are dependent on the lithologic character of different basaltic flow units and the existing physiography. Although rainfall, its seasonality and areas of recharge, play vital roles in the recharge of these springs, their yields are also controlled by lithological variations and hydraulic characteristics of their source-aquifers. Chemical concentrations of these springs are heavily dependent on the lithological compositions of the source-aquifers and the residence time of groundwater in these aquifers. Currently, basaltic springs are classified with those issuing from other terrains. However, because the emergence of groundwater in the form of springs is largely controlled by the lithology and the resulting water-bearing properties of the formations, a new classification scheme is proposed that classifies the springs on the basis of their source-aquifers. While tapping springs for drinking/irrigation purposes, it must be remembered that they also sustain thousands of other life forms vital to a balanced ecosystem. Changes in the uses of these springs may also affect other human communities downstream. Therefore, before developing spring flow, a trade-off must be made considering local needs and downstream users. Emphasizing only local human needs may lead to severe intercommunity conflict and negative environmental consequences. Electronic Publication  相似文献   

Materializing post-colonial geographies: examining the textural landscapes of migration in the South Asian home   总被引：2，自引：0，他引：2  

Divya P. Tolia-Kelly   《Geoforum》2004,35(6):675-688

This paper considers the role of visual cultures in understanding the value of landscape to post-colonial migrants living in Britain. The paper also considers these visual cultures as prismatic devices which refract lived landscapes of South Asia and East Africa into British domestic scene. The visual cultures are investigated using a materialist lens. They are positioned as materials that allow embodied connections to landscapes experienced pre-migration, including sensory connections with past homes, natures and family life. These then become artefacts symbolising relationships with past landscapes, made meaningful in their presence in Britain homes. Using this materialist lens, visual cultures in the British Asian home, such as photographs, pictures, and paintings, are given meaning and value beyond their textual content. This paper is an exercise in reading visual cultures in the everyday through a materialist lens which allows for an examination of their place in the process of ‘making home' for South Asian women in Britain. In particular, objects presence the migratory experience of the South Asian community, importing ‘other' landscapes (previously shaped by colonial governance) into Britain, and help to shape environmental values, landscape imaginaries and South Asian landscapes of belonging in the post-colonial period.  相似文献   

(Im)mobilization of soil heavy metals using CaO,FA, sulfur,and Na<Subscript>2</Subscript>S: a 1-year incubation study     

A. Mahar  P. Wang  A. Ali  A. H. Lahori  M. K. Awasthi  Z. Wang  Z. Guo  Q. Wang  S. Feng  R. Li  Z. Zhang 《International Journal of Environmental Science and Technology》2018,15(3):607-620

The immobilization of heavy metals (HMs)-contaminated soils using amendments is a cost-effective remediation technique. Therefore, the aim of this study was to evaluate the effectiveness and aging factor of CaO, fly ash (FA), sulfur, and Na₂S on the immobilization of Cd, Cu, and Pb in three different contaminated soils under 1-year incubation. The study sites (S) and amendments treatments (T) are termed as S1, S2, and S3 and T1, T2, T3, and T4, respectively. The TCLP-extractable HMs were analyzed in treated soils after 2, 6, and 12 months. The higher concentrations of CaO, FA, and Na₂S (T3 and T4) efficiently immobilized the Cd. However, a moderate Cd decrease was noted in sulfur-treated samples with no significant difference in ratios as compared to control in used soils. Likewise, CaO decreased moderately Cu content in used soils with gradual increase in Cu mobility. Similarly, FA, sulfur, and Na₂S showed effective immobilization of Cu content with no difference in treatment ratios as compared to control. In addition, CaO, sulfur, and Na₂S decreased the significant content of Pb as compared to control. However, FA treatments showed moderate reduction in Pb content with no difference in ratios. The higher concentrations of alkaline amendments should be avoided in the farmland soils as they increase the soil pH and EC of soil ecosystem. The higher ratios of alkaline amendments would be suitable to remediate the abandoned lands/brownfields. The sulfur amendment would be suitable for immobilization of metals in alkaline soils rather than in acidic soils.  相似文献   

Tracing ionic sources and geochemical evolution of groundwater in the Intermountain Una basin in outer NW Himalaya,Himachal Pradesh,India     

Divya Thakur  S. K. Bartarya  H. C. Nainwal 《Environmental Earth Sciences》2018,77(20):720

The present research aims to identify sources of ions and factors controlling the geochemical evolution of groundwater in an intermountain basin, comprising hill and valley fill region, of Outer Himalaya in Himachal Pradesh, India. The groundwater samples collected from 81 tubewells and handpumps are analyzed for major ions, trace metals and stable isotopes (δ¹⁸O and δD). Geochemically the dominant hydrochemical facies in the Una basin are Ca–HCO₃, Ca–Mg–HCO₃ and Na–Cl types at few locations. A relatively lower ionic concentration in the valley fills indicates dilution and low residence time of water to interact with the aquifer mass due to high porosity and permeability. The ionic ratios of 0.9, 0.8 and 3.8 to 5.7, respectively, for (Ca?+?Mg): HCO₃, (Ca?+?Mg): (HCO₃?+?SO₄) and Na: Cl, suggests that ionic composition of groundwater is mainly controlled by rock weathering of, particularly by dissolution/precipitation of calcrete and calcite hosted in rock veins and Ca–Na feldspar hosted in conglomerate deposits derived from the Higher and Lesser Himalaya during the formation of Siwalik rocks. Although Na, K, NO₃ and SO₄ are introduced in the groundwater through agricultural practices, Na has also been introduced through ion exchange processes that have occurred during water–rock interaction, as indicated by negative CAI values. Factor analysis further suggests three major factors affecting the water chemistry of the area. The first two factors are associated with rock weathering while the third is anthropogenic processes associated with high nitrate and iron concentration. High concentrations of Fe and Mn ions that are exceeded that of WHO and BIS standards are also present at few locations. The recharge of groundwater in the Outer Himalaya is entirely through Indian Southwest Monsoon (ISM) and depleted ratios of δ¹⁸O/δD in valley region indicate infiltration from irrigation in recharging the groundwater and fractionation of isotopes of precipitation due to evaporation before infiltration. High d-excess values and inverse relation with δ¹⁸O are indicative of secondary evaporation of precipitation during recharge of groundwater.  相似文献   

Aerosol characteristics at Patiala during ICARB—2006     

Manjit Singh  Darshan Singh  P. Pant 《Journal of Earth System Science》2008,117(1):407-411

The spectral AOD measurements have been made for the first time over Patiala during multi-platform field campaign ICARB—2006 using a Multi-Wavelength Radiometer (MWR) along with the suspended particulate matter measurements with a high volume sampler. Spectral AOD has higher values in May in comparison to March and April. The monthly mean AOD values at 500 nm are 0.26 ± 0.08, 0.36 ± 0.19 and 0.58 ± 0.20 for the months of March, April and May respectively. The mean AOD is more during afternoon in comparison to forenoon at all wavelengths. The atmospheric turbidity is higher in May and is attributed to dust transported by southerly winds prevailing during this month. The Ångström parameter α varies between zero and 0.68 while β ranges from 0.1 to 0.9. The columnar water vapour content ranges from 0.12 to 2.92 cm, having a mean value of 1.06 ± 0.648 cm. The mean total suspended particulate matter is 334.41 ± 97.56 μgm/m³, an indication of high aerosol loading over Patiala during the campaign period.  相似文献