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71.
The head Bay region bordering the Bay of Bengal is highly vulnerable to tropical cyclones. Catastrophic risks from storm surge and associated inundation are quite high due to high population density in coastal areas, socio-economic conditions, and shallow bathymetry. It features the world’s largest deltaic system comprising of ‘Sunderbans’ bordered by West Bengal and Bangladesh. In a geomorphologic sense, the head Bay region is a low-lying belt comprising several barrier islands and river drainage systems, numerous tidal creeks, and mud flats having a high risk for widespread inundation. In addition, the high tidal range together with low-lying topography leads to high risk and vulnerability from storm surge inundation. During May 2009, a severe cyclonic storm Aila struck West Bengal causing enormous destruction to life and property along coastal belts of West Bengal and Bangladesh. It was the strongest pre-monsoon cyclone in the past two decades that had landfall in West Bengal. This work reports on a numerical study for hypothetical storm surge and associated inundation from Aila using the ADCIRC model. The study covers a comprehensive qualitative analysis on water level elevation and onshore inundation for West Bengal and Bangladesh regions. The estimated peak storm surge was about 4 m in the Sunderban region that propagated into all major riverine systems, inundating the river banks as well the inland areas. Numerical simulations indicate an average inland penetration distance of 350 m with a maximum of 600 m at various coastal locations in West Bengal and Bangladesh. The study emphasizes the need and importance of inundation modeling system required for emergency preparedness and disaster management.  相似文献   
72.
While the concept of sustainable land management is now widely accepted, there remains considerable scope for developing location-specific land-use indicators for sustainability evaluation. A study was conducted to investigate the indicators of land-use sustainability in the context of tropical agro-ecosystems using the case of Sakaekrang watershed, Thailand. The biophysical data were generated from Geographic Information Systems (GIs) and the socioeconomic data were collected through a field survey. In the light of sustainable land management objectives, a total of 32 criteria were considered in the analysis to determine land-use sustainability and identify indicators that best explain the sustainability level. About one quarter of the agricultural area in the watershed meets the sustainability threshold, indicating a substantial unstable area in the watershed. Among 11 indicators that showed a significant relationship with the computed land-use sustainability, land quality, source of farm income, and evapo transpiration were the most important.  相似文献   
73.
Simulating future land use and ecosystem services in Northern Thailand   总被引:1,自引:0,他引:1  
Enhancing ecosystem services is important as it provides foundation for the wellbeing of people. This paper presents the future land use simulation for enhancing ecosystem services using CLUMondo dynamic spatial model. The land use change was assessed from 1989 to 2013 in Wang Thong watershed of Northern Thailand using GIS and a set of ecosystem services was assessed using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model. Future land uses until 2030 were projected for three policy scenarios, namely business-as-usual, integrated land use development, and enhancing environmental services with different levels of emphasis on ecosystem services. In business-as-usual scenario, it was observed that ecosystem services will decline by 2030 from the base year of 2013, whereas in integrated land use development scenario, the ecosystem services will increase by 5% compared to base year due to anticipated effective protection of remaining forests in all existing and proposed protected areas of the study area. In enhancing environmental services scenario, the ecosystem services will increase by 15%. Such results can serve as useful information in policy formulation in developing land use options, which help enhance ecosystem services in future.  相似文献   
74.
The extent of accumulation of some heavy metals in root and aerial plant parts, total chlorophyll, protein and yield of C. cajan exposed to mine spoil were investigated. Chlorophyll and protein level on the control site increased from the basal level to 1.49 fold and 1.92 fold respectively on 150 d and attained a plateau within 210 d. The maximum decline in leaf protein and yield in selected mine spoil has been observed 37% (18.46 mg g(-1) fresh wt) and 76% at 150 d and maintained a slight decline when duration was extended up to 210 d as compared to control. Whereas in case of photo pigment content (Chlorophyll a and b) the maximum reduction was almost 42% (0.786 mg g(-1) fresh wt) during 210 d from its basal level. Plant tissues have accumulated maximum level of selected cations in control and mine spoil in the order (Fe > Mn > Zn > Cu > Pb > Ni > Cr > Cd). Metal accumulation in different plant parts was observed in the decreasing order roots > shoots > leaves > seeds. Invariably high accumulation of such cations in roots overshoots indicated accumulation, retention or restricted translocation from root to shoot. The metal share of seed varied from 1.3-39.5 fold as compared to their respective controls but their amount was quite below the toxic range. Thus the present work explores the metal accumulation in the plant tissues.  相似文献   
75.
Environmental Science and Pollution Research - Highly bioavailable plant phospholipid complex that can reverse aluminum maltolate (AlM)–induced toxicity is not yet reported. Hence, the...  相似文献   
76.
The paper briefly describes an electro-optical system for counting of dust particles, which is based on the scattering phenomena.Utilizing the scattering of light by various size particles present in the environment, various particle counting techniques have been developed in order to measure the scattered intensity of light. Light scatters in all directions but much more in the so-called near forward direction 17 off axis, at 163 from the light source in the visible range.On the basis of two techniques, the right angle and forward angle scattering, opto-mechanical systems have been developed which measure scattered intensity and particulate matter. The forward scattering Nephelometer is more sensitive and therefore is more suitable for pollution monitoring than the right angle scattering Nephelometer. Whereas the right angle scattering Nephelometer has the utility in extremely low concentration in ppb level owing to the excellent light trap efficiency in comparison to forward scattering Nephelometer. In this paper measurement techniques and measurement results associated with design and development of a real time particle analyser are also discussed.  相似文献   
77.
The Syabru-Bensi hydrothermal zone, Langtang region (Nepal), is characterized by high radon-222 and CO2 discharge. Seasonal variations of gas fluxes were studied on a reference transect in a newly discovered gas discharge zone. Radon-222 and CO2 fluxes were measured with the accumulation chamber technique, coupled with the scintillation flask method for radon. In the reference transect, fluxes reach exceptional mean values, as high as 8700 ± 1500 g m−2 d−1 for CO2 and 3400 ± 100 × 10−3 Bq m−2 s−1 for radon. Gases fluxes were measured in September 2007 during the monsoon and during the dry winter season, in December 2007 to January 2008 and in December 2008 to January 2009. Contrary to expectations, radon and its carrier gas fluxes were similar during both seasons. The integrated flux along this transect was approximately the same for radon, with a small increase of 11 ± 4% during the wet season, whereas it was reduced by 38 ± 5% during the monsoon for CO2. In order to account for the persistence of the high gas emissions during monsoon, watering experiments have been performed at selected radon measurement points. After watering, radon flux decreased within 5 min by a factor of 2–7 depending on the point. Subsequently, it returned to its original value, firstly, by an initial partial recovery within 3–4 h, followed by a slow relaxation, lasting around 10 h and possibly superimposed by diurnal variations. Monsoon, in this part of the Himalayas, proceeds generally by brutal rainfall events separated by two- or three-day lapses. Thus, the recovery ability shown in the watering experiments accounts for the observed long-term persistence of gas discharge. This persistence is an important asset for long-term monitoring, for example to study possible temporal variations associated with stress accumulation and release.  相似文献   
78.
Environmental Chemistry Letters - The decrease in fossil fuel usage and the projected 28% increase in the global energy demand by 2040 are calling for advanced methods to convert modern biomass...  相似文献   
79.
This study simulated crop and water yields in the Missouri River Basin (MRB; 1,371,000 km2), one of the largest river basins in the United States, using the Soil and Water Assessment Tool (SWAT) at a fine resolution of 12‐digit Hydrological Unit Codes (HUCs) using the regionalization calibration approach. Very few studies have simulated the entire MRB, and those that have developed were at a coarser resolution of 8‐digit HUCs and were minimally calibrated. The MRB was first divided into three subbasins and was further divided into eleven regions. A “head watershed” was selected in each region and was calibrated for crop and water yields. The parameters from the calibrated head watershed were extrapolated to other subwatersheds in the region to complete comprehensive spatial calibration. The simulated crop yields at the head watersheds were in close agreement with observed crop yields. Spatial validation of the aggregated crop yields resulted in reasonable predictions for all crops except dryland corn in a few regions. Simulated and observed water yields in head watersheds and also in the validation locations were in close agreement in naturalized streams and poor agreement in streams with high groundwater‐surface water interactions and/or reservoirs found upstream of the gauges. Overall, the SWAT model was able to reasonably capture the hydrological and crop growth dynamics occurring in the basin despite some limitations.  相似文献   
80.
Jatropha curcas L. (Jatropha) is an important multipurpose tree valued for oil. In India, plans are underway to bring substantial area under this crop for meeting the biofuel requirements of the country. A study was conducted to develop allometric relationships in Jatropha to predict various biomass-related components (above ground and below ground) using easily measurable attributes, viz. collar diameter, tree height, number of branches, crown diameter, and crown depth. Further, it was aimed to establish the reliability of these relationships using an independent dataset obtained from varied management situations. Destructive sampling was carried out during the rainy season of 2011, when Jatropha plants were eight years old. Highly significant allometric relationships (F-values significant at 1% level) were obtained while predicting various biomass components (above, below, and total) using easily measurable attributes with R2 values ranging from 0.89 to 0.98. Of all the predictors, collar diameter exhibited a highly significant relationship with total dry biomass per plant (R2 = 0.97). The allometric relationships developed were validated with an independent dataset. The allometric relationships developed would serve as valuable tools for estimating total dry biomass production and carbon sequestration with reasonable accuracy in Jatropha systems, as they are proposed to be taken up in substantial area in the years to come.  相似文献   
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