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1.
The Barind tract of West Bengal is an area of tropical sub-humid region composed of old alluvial soil. The area has high water demand due to growing population pressure and intensification in agricultural activity. These create huge stress on surface and ground water availability. Continuous withdrawal of ground water has become an alternative source of irrigation water which has also again made the condition critical. Ground water level has been lowered down drastically in many parts in this region. Under this circumstance, it is necessary to delineate potential ground water-bearing layers. Therefore, the present study attempts to identify potential ground water-bearing zones to manage ground water effectively. Instead of usually used parameters for ground water potentiality delineation here only some particular litholog parameters like breadth of water-bearing layer, depth of water-bearing layer, presence of clay layer above or below major water-bearing layer have been considered for delimiting the same. The result shows that out of total area, 60% area (405,382.2 ha) falls under very low to low potential ground water-bearing zone and only 8.19% area (55,634.97 ha) is potential. Considering this spatial pattern of ground water availability, harvesting structure and magnitude of water withdrawing should be designed. 相似文献
2.
Detention Outlet Retrofit Improves the Functionality of Existing Detention Basins by Reducing Erosive Flows in Receiving Channels 下载免费PDF全文
Robert J. Hawley James A. Goodrich Nora L. Korth Christopher J. Rust Elizabeth V. Fet Craig Frye Katherine R. MacMannis Matthew S. Wooten Mark Jacobs Rajib Sinha 《Journal of the American Water Resources Association》2017,53(5):1032-1047
By discharging excess stormwater at rates that more frequently exceed the critical flow for stream erosion, conventional detention basins often contribute to increased channel instability in urban and suburban systems that can be detrimental to aquatic habitat and water quality, as well as adjacent property and infrastructure. However, these ubiquitous assets, valued at approximately $600,000 per km2 in a representative suburban watershed, are ideal candidates to aid in reversing such cycles of channel degradation because improving their functionality would not necessarily require property acquisition or heavy construction. The objective of this research was to develop a simple, cost‐effective device that could be installed in detention basin outlets to reduce the erosive power of the relatively frequent storm events (~ < two‐year recurrence) and provide a passive bypass to maintain flood control performance during infrequent storms (such as the 100‐year recurrence). Results from a pilot installation show that the Detain H2O device reduced the cumulative sediment transport capacity of the preretrofit condition by greater than 40%, and contributed to reduced flashiness and prolonged baseflows in receiving streams. When scaling the strategy across a watershed, these results suggest that potential gains in water quality and stream channel stability could be achieved at costs that are orders of magnitude less than comparable benefits from newly constructed stormwater control measures. 相似文献
3.
Recent catastrophic floods in Viet Nam have been increasingly linked to land use and forest cover change in the uplands. Despite the doubts that many scientists have expressed on such nexus, this common view prompted both positive forest protection/reforestation programs and often-unwarranted blame on upland communities for their forest management practices. This study discusses the disparity between public perceptions and scientific evidences relating the causes of catastrophic floods. The former was drawn on the results of a questionnaire and focus groups discussions with key informants of different mountainous communities, whereas the latter was based on GIS and remote sensing analysis of land cover change, including a statistical analysis of hydro-meteorological data of the Huong river basin in Viet Nam. Results indicate that there is a gap between the common beliefs and the actual relationship between the forest cover change and catastrophic floods. Undeniably, the studied areas showed significant changes in land cover over the period 1989–2008, yet, 71% of the variance of catastrophic flood level in the downstream areas appeared related to variance in rainfall. Evidences from this study showed that the overall increasing trends of catastrophic flooding in the Huong river basin was mainly due to climate variability and to the development of main roads and dyke infrastructures in the lowlands. Forest management policies and programs, shaped on the common assumption that forest degradation in the upland is the main cause of catastrophic flood in the downstream areas, should be reassessed to avoid unnecessary strain on upland people. 相似文献
4.
Results derived from the Climate Disaster Resilience Index (CDRI)—consisting of five dimensions (economic, institutional, natural, physical, and social), 25 parameters, and 125 variables—reflect the abilities of people and institutions to respond to potential climate‐related disasters in Chennai, India. The findings of this assessment, applied in the 10 administrative zones of the city, reveal that communities living in the northern and older parts of Chennai have lower overall resilience as compared to the flourishing areas (vis‐à‐vis economic growth and population) along the urban fringes. The higher resilience of communities along the urban fringes suggests that urbanisation may not necessarily lead to a deterioration of basic urban services, such as electricity, housing, and water. This indication is confirmed by a strong statistical correlation between physical resilience and population growth in Chennai. The identification of the resilience of different urban areas of Chennai has the potential to support future planning decisions on the city's scheduled expansion. 相似文献
5.
Bhattacharyya Sudip Poi Rajlakshmi Mandal Swagata Baskey Sen Moni Hazra Dipak Kumar Saha Supradip Karmakar Rajib 《Environmental science and pollution research international》2022,29(12):17174-17187
Environmental Science and Pollution Research - A liquid–liquid extraction (LLE) method was validated as per SANTE/12682/2019 guidelines for gas chromatography–mass spectrometric... 相似文献
6.
Fishery resource management in Chilika lagoon: a study on coastal conservation in the Eastern Coast of India 总被引:1,自引:0,他引:1
A significant proportion of the fishing population comprises small-scale fishermen and many studies illustrate that these
people are exploited by middlemen in the process of fish marketing combined with money lending. The negative dependency gives
rise to poverty and triggers indiscriminate fish catch that threatens fishery resources depletion. This article explores the
root causes of failures in resource-led development from the viewpoint of coastal resource conservation. The study presents
a case study of Chilika lagoon, India and focuses on the interaction between small-scale fishermen and middlemen. The findings
reveal that most of the small-scale fishermen have been exploited by specific middlemen and the underlying causes of the present
fish marketing structure stem from (i) indebtedness and (ii) the unstable situation because of perpetual conflicts over fishery
resources among the fishers across Chilika lagoon. Based on these observations, this article presents some recommendations
on fishery resource conservation from the perspective of a fish marketing structure.
相似文献
Rajib ShawEmail: |
7.
Human security is linked to people’s access to natural resources and vulnerabilities to environmental change. In the case
study of Chilika lagoon, the findings reveal that insecurity linked to natural resources is largely embedded in the historical
process of resource allocation among stakeholders, rather than on the presence of resource stocks. The insecurities are strongly
tied not only to allocation changes, but also to multiple factors (environmental, technological, and demographic factors).
Based on the Chilika lagoon experience, this article develops a pathway toward a clear understanding of the linkage between
human security and natural resources in a local context. 相似文献
8.
The need for environmental and urban planning reached a critical point in the year 2007, when one-half of the world's population
could be defined as living in cities. Urbanisation in India is also increasing at a fast rate. Urban chaos in India, emanating
from the continuous ignorance of fragile ecosystems, calls for the reshaping of existing cities as ‘eco-cities’. The ‘eco-city’—a
well-known concept in the western world—is new to the Indian context. While western connotations of eco-cities should not
be discarded outright in the context of India, core concerns vary significantly for obvious reasons. Recognising two facts—firstly,
eco-city development is altogether a fresh approach to human settlement development in India, and, secondly, the manifold
increase in the vulnerability of cities—this paper discusses documented good practice, reinforcing evolution towards the eco-city
vision. Lessons drawn from the examples cited are further deconstructed in the light of their contribution to urban risk reduction,
which provides direction to appreciating the ‘disaster-resilient eco-community’ concept in Puri, a coastal city in India.
Further, this paper attempts to unravel existing community-based practices in Puri, which are boon to the local environment
and invariably reduce disaster risk. These seemingly modest neighbourhood initiatives symbolise immense societal wealth, which
can be calibrated appropriately for reducing urban environmental risk as well. This paper also illustrates how a ‘disaster
resilient eco-community’ approach is inevitable in the present and future contexts not only to preserve sustainable development
gains but also to secure human well-being. 相似文献
9.
Rajib Karmakar Shashi B. Singh Gita Kulshrestha 《Journal of environmental science and health. Part. B》2013,48(5):435-441
The degradation of thiamethoxam [(EZ)-3-(2-chloro-1,3-thiazol-5-yl-methyl)-5-methyl-1,3,5-oxadiazinan-4-ylidene (nitro) amine] insecticide in buffers at different pH and temperature levels was investigated in laboratory studies. Acidic hydrolysis under conventional heating conditions and alkaline hydrolysis under both conventional heating and microwave conditions were carried out. Different hydrolysis products were found to form under alkaline and acidic conditions. Hydrolysis of thiamethoxam in acidic, neutral and alkaline buffers followed first-order reaction rate kinetics at pH 4, 7 and 9.2, respectively. Thiamethoxam readily hydrolyzed in alkaline buffer but was comparatively stable in neutral buffer solution. The main products formed under different conditions were characterized on the basis of infrared (IR), 1H-NMR and Mass spectroscopy. The possible mechanisms for the formation of these hydrolysis products have also been proposed. 相似文献
10.
Coastal hazards and community-coping methods in Bangladesh 总被引:1,自引:0,他引:1
Addressing one of the most vulnerable coastal communities in Bangladesh, this paper explores people’s perception and vulnerabilities
to coastal hazards. At the same time, it investigates the methods that communities apply to cope with different coastal hazards.
Findings revealed that people perceived an increase in both the intensity of hazards and their vulnerabilities. In spite of
having a number of socio-economic and locational factors enhancing their vulnerabilities, the community is creating their
own ways to cope with these hazards. For different aspects of life like shelter, employment, water supply, and health, communities
apply different coping methods that vary with the types of hazard. Efforts have also been made by governments and NGOs to
manage coastal hazards. By highlighting both community-coping methods and efforts of development organizations, this paper
attempts to devise an integrated approach for managing the coastal hazards that occur in Bangladesh. 相似文献