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41.
Vikram M. Vyas Saichiu N. Tong Christopher Uchrin Panos G. Georgopoulos Gail P. Carter 《Journal of the American Water Resources Association》2004,40(1):187-195
ABSTRACT: The Kirkwood‐Cohansey aquifer has been identified as a critical source for meeting existing and expected water supply needs for southern New Jersey. Several contaminated sites exist in the region; their impact on the aquifer has to be evaluated using ground water flow and transport models. Ground water modeling depends on availability of measured hydrogeologic data (e.g., hydraulic conductivity, for parameterization of the modeling runs). However, field measurements of such critical data have inadequate spatial density, and their locations are often clustered. The goal of this study was to research, compile, and geocode existing data, then use geostatistics and advanced mapping methods to develop a map of horizontal hydraulic conductivity for the Kirkwood‐Cohansey aquifer. Spatial interpolation of horizontal hydraulic conductivity measurements was performed using the Bayesian Maximum Entropy (BME) Method implemented in the BMELib code library. This involved the integration of actual measurements with soft information on likely ranges of hydraulic conductivity at a given location to obtain estimate maps. The estimation error variance maps provide an insight into the uncertainty associated with the estimates, and indicate areas where more information on hydraulic conductivity is required. 相似文献
42.
Vikram Ravi Joseph K. Vaughan Michael P. Wolcott Brian K. Lamb 《Journal of the Air & Waste Management Association (1995)》2019,69(3):289-304
Using a WRF-SMOKE-CMAQ modeling framework, we investigate the impacts of smoke from prescribed fires on model performance, regional and loc al air quality, health impacts, and visibility in protected natural environments using three different prescribed fire emission scenarios: 100% fire, no fire, and 30% fire. The 30% fire case reflects a 70% reduction in fire activities due to harvesting of logging residues for use as a feedstock for a potential aviation biofuel supply chain. Overall model performance improves for several performance metrics when fire emissions are included, especially for organic carbon, irrespective of the model goals and criteria used. This effect on model performance is more pronounced for the rural and remote IMPROVE sites for organic carbon and total PM2.5. A reduction in prescribed fire emissions (30% fire case) results in significant improvement in air quality in areas in western Oregon, northern Idaho, and western Montana, where most prescribed fires occur. Prescribed burning contributes to visibility impairment, and a relatively large portion of protected class I areas will benefit from a reduced emission scenario. For the haziest 20% days, prescribed burning is an important source of visibility impairment, and approximately 50% of IMPROVE sites in the model domain show a significant improvement in visibility for the reduced fire case. Using BenMAP, a health impact assessment tool, we show that several hundred additional deaths, several thousand upper and lower respiratory symptom cases, several hundred bronchitis cases, and more than 35,000 workday losses can be attributed to prescribed fires, and these health impacts decrease by 25–30% when a 30% fire emission scenario is considered.
Implications: This study assesses the potential regional and local air quality, public health, and visibility impacts from prescribed burning activities, as well as benefits that can be achieved by a potential reduction in emissions for a scenario where biomass is harvested for conversion to biofuel. As prescribed burning activities become more frequent, they can be more detrimental for air quality and health. Forest residue-based biofuel industry can be source of cleaner fuel with co-benefits of improved air quality, reduction in health impacts, and improved visibility. 相似文献
43.
Fereidoun Mobasheri Vikram S. Budhraja Frank E. Mack 《Journal of the American Water Resources Association》1971,7(4):823-830
ABSTRACT Mathematical models are formulated for selection of water resources projects to meet the future additional water requirements of a given region at the minimum present worth cost. The projects available are surface water reservoirs and desalination plants. The modles are used for selecting both the development sequence of projects and their optimum sizes. Decisions with regard to planning time horizon and discount rates are made outside of the mathematical model. The algorithm used for solving these models is an integer programming routine using the implicit enumeration technique. Some computational results are presented for a hypothetical case. 相似文献
44.
The present investigation determined the effects of epibrassinolide (EBL) on the levels of indole-3-acetic acid (IAA), abscisic acid (ABA), and polyamine (PA) and antioxidant potential of 7-d old Raphanus sativus L. cv. ‘Pusa chetki’ seedlings grown under Cr (VI) metal stress. Reduced titers of free (0.767 μg g−1 FW) and bound (0.545 μg g−1 FW) IAA in Cr (VI) stressed seedlings were observed over untreated control. Supplementations of EBL to Cr (VI) stressed seedlings were able to enhance both free (2.14-5.68 μg g−1 FW) and bound IAA (2.45-7.78 μg g−1 FW) concentrations in comparison to Cr (VI) metal treatment alone. Significant rise in free (13.49 μg g−1 FW) and bound (12.17 μg g−1 FW) ABA contents were noticed for Cr (VI) stressed seedlings when compared to untreated control. No significant increase in ABA contents were recorded for Cr (VI) stressed seedlings upon supplementation with EBL over Cr (VI) treatment alone. A significant increase in Put (18.40 μg g−1 FW) and Cad (9.08 μg g−1 FW) contents were found for 10−9 M EBL plus Cr (VI) metal treatments when compared to Cr (VI) treatment alone. Spermidine (Spd) contents were found to decline significantly for EBL treatment alone or when supplemented with Cr (VI) treatments over untreated controls and Cr (VI) treatment alone. Antioxidant levels were found to enhance, with glutathione (57.98 mg g−1 FW), proline (4.97 mg g−1 FW), glycinebetaine (39.01 μmol mL−1), ascorbic acid (3.17 mg g−1 FW) and phytochelatins (65.69 μmol g−1 FW) contents noted for EBL supplemented to Cr (VI) metal solution over Cr (VI) treatment alone. Reduced activities of guaiacol peroxidase (0.391 U mg−1 protein) and catalase (0.221 U mg−1 protein) and enhanced activities of glutathione reductase (7.14 U mg−1 protein), superoxide dismutase (15.20 U mg−1 protein) and ascorbate peroxidase (4.31 U mg−1 protein) were observed in seedlings treated with EBL plus Cr (VI) over Cr metal treatment alone. Reduced MDA (2.55 μmol g−1 FW) and H2O2 (33.24 μmol g−1 FW) contents were recorded for 10−9 M EBL supplemented to Cr (VI) stress over Cr (VI) treatment alone. Enhancement in free radical scavenging potential as indicated by higher values of 1,1-diphenylpicrylhydrazyl, deoxyribose and reducing power activity assays, and increased levels of phenols and soluble sugars also showed significant influence of EBL in alleviating Cr (VI) stress in radish seedlings. 相似文献
45.
46.
A sharp decline in the water level in Jaipur city and its hinterland region in NW India has been observed during the last
decades. Such a drop can be correlated with a widening gap between groundwater draft and recharge resulting from poor and
erratic rainfall and over-exploitation of groundwater resources. The city has undergone uncontrolled urban expansion complete
with a multifold rise in the population, which now stands at more than 3.3 million. Drying up of the surface water bodies
has further led to a total dependence on groundwater resources to meet the rising domestic and industrial demand for water.
There are about 1,000 bore wells drilled by Governmental agencies and an estimated 11,000 privately owned ones. The water
is generally alkaline carbonate–bicarbonate type. We evaluated water quality for the period between 1993 and 2001 and observed
notable deterioration that we attribute to inadequate recharge and a change in the potential water-bearing zones from alluvium
to granite–gneiss bedrocks, caused by a drop in the water table. In addition, we also attribute the problem of high nitrate
in groundwater in densely populated parts of Jaipur city to improper sewage disposal. 相似文献
47.
Kylie Soanes Michael Sievers Yung En Chee Nicholas S. G. Williams Manisha Bhardwaj Adrian J. Marshall Kirsten M. Parris 《Conservation biology》2019,33(2):300-306
Despite repeated calls to action, proposals for urban conservation are often met with surprise or scepticism. There remains a pervasive narrative in policy, practice, and the public psyche that urban environments, although useful for engaging people with nature or providing ecosystem services, are of little conservation value. We argue that the tendency to overlook the conservation value of urban environments stems from misconceptions about the ability of native species to persist within cities and towns and that this, in turn, hinders effective conservation action. However, recent scientific evidence shows that these assumptions do not always hold. Although it is generally true that increasing the size, quality, and connectivity of habitat patches will improve the probability that a species can persist, the inverse is not that small, degraded, or fragmented habitats found in urban environments are worthless. In light of these findings we propose updated messages that guide and inspire researchers, practitioners, and decision makers to undertake conservation action in urban environments: consider small spaces, recognize unconventional habitats, test creative solutions, and use science to minimize the impacts of future urban development. 相似文献
48.
Summary. Males of the moth Utetheisa ornatrix produce a pheromone, hydroxydanaidal, contained in two brush-like organs, the coremata, which they evert during courtship. Hydroxydanaidal is derived chemically by the males from pyrrolizidine alkaloids that they sequester from their larval food plants. It had been shown previously that the amount of hydroxydanaidal in the coremata correlates positively with a number of male parameters that are a measure of the male’s “worth.” Hydroxydanaidal could thus be used by the female as a basis for discrimination in courtship. Experiments carried out with virgin Utetheisa had shown that females do indeed mate selectively with males of high corematal hydroxydanaidal content, thereby accruing the multiple benefits that are the consequence of such selectivity. Unresolved was the question whether corematal hydroxydanaidal could still provide a basis for female appraisal of suitors when these had previously mated. Given the proven promiscuity of the female, male Utetheisa could be expected to be promiscuous as well. Evidence we present here shows that field-collected males, which could be expected to be mostly non-virginal, are of reduced acceptability to females. They are also, on average, in possession of lower quantities of hydroxydanaidal, explaining possibly why they should be held in lesser regard. At low levels, however, hydroxydanaidal does not lend itself for precise assessment of male worth, because as we show herein, at such levels, the compound does not correlate with any of the criteria of male quality (male size, spermatophore mass, male pyrrolizidine alkaloid content, amount of pyrrolizidine alkaloid transmitted to the female). Males that have mated beforehand are therefore likely not to be classed into subcategories by the females, but simply as belonging to one category of “less desirables”. The significance of these findings to our understanding of the mating strategy of Utetheisa is discussed. 相似文献
49.
Vikram S. Negi Ravi Pathak K. Chandra Sekar R.S. Rawal I.D. Bhatt S.K. Nandi 《Journal of Environmental Planning and Management》2018,61(10):1722-1743
Ethnobotanical knowledge plays a significant role in plant diversity conservation and the curing of various ailments in remote rural areas of the Indian Himalayan Region (IHR). A total of 53 plant species from 27 families have been documented from the Byans valley and are used traditionally for the treatment of various diseases. Valley inhabitants have maintained a symbiotic relationship between natural resources and their cultural belief system by developing sacred forests/groves which conserve the region's plant diversity pool. Information on sacred natural sites and traditional beliefs was documented in order to understand the environmental and conservationist implications of these rules and practices. The study provides comprehensive information about eroding traditional knowledge and biodiversity conservation practices. This study could be a pilot to strengthen the conservation practices and sustainable utilization of frequently used bioresources by understanding the traditional knowledge system and conservation ethics of tribal communities in the Himalayan region. 相似文献
50.
In recent years, the problem of fluoride in Nawa tehsil (Nagaur district) has reached at an alarming proportion. In the last
decades, the water table of the Nawa tehsil has fallen. With the lowering of the water table, the amount of fluoride has increased
in the subsoil water which is used by the villagers when drawn through hand pumps, tube wells etc. So the present study illustrates
the groundwater quality of randomly selected villages of Nawa tehsil. The highest fluoride concentration was found in Rulaniyo
ki Dhani i.e. 14.62 ppm. The excessive intake of fluoride resulted in dental and skeletal fluorosis. 相似文献