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Narsimha Adimalla - One of the best experts on this subject based on the ideXlab platform.
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controlling factors and mechanism of groundwater quality variation in semiarid Region of south india an approach of water quality index wqi and health risk assessment hra
Environmental Geochemistry and Health, 2020Co-Authors: Narsimha AdimallaAbstract:The Study Region comprises fractured granitic, basaltic and lateritic aquifer system constituted by Precambrian rocks. Groundwater is the primary source for drinking and household needs. Its quality is a big issue in the three aquifers, which are mostly of human health concern. Many developing Regions suffer from lack of safe drinking water, thereby health problems arise in many parts of the Regions, and Telangana state is one of them. For this reason, 194 groundwater samples were collected and analyzed for fluoride, nitrate, chloride and other physicochemical parameters. The concentrations of fluoride (F−), nitrate (NO3−), magnesium (Mg2+), total dissolved solids and total hardness are above the acceptable limits for drinking purposes, prescribed by the World Health Organization. The higher concentrations of fluoride and nitrate in drinking water cause health hazards, and above 50% of the groundwater samples are not suitable for drinking purposes with respect to fluoride and nitrate. Weathering of rocks and dissolution of fluoride-bearing minerals can be a cause for higher fluoride concentrations, while anthropogenic sources are one of the major reasons for higher nitrate concentrations in the Study area. Groundwater suitability for irrigation suggests that more than 90% of the groundwater sampling locations are suitable for irrigation. In addition, health risk assessments were evaluated by using the United States Environmental Protection Agency model, to determine the non-carcinogenic risk of fluoride and nitrate in drinking water for adults (females and males) and children. The ranges of hazard index in all sampling locations are varied from 0.133 to 8.870 for males, 0.146 to 10.293 for females and 0.419 to 29.487 for children, respectively. The health risk assessment results indicated that children were more exposed to health risk, due to the intake of high contaminated drinking water with respective of nitrate and fluoride in the Study Region.
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groundwater quality evaluation using water quality index wqi for drinking purposes and human health risk hhr assessment in an agricultural Region of nanganur south india
Ecotoxicology and Environmental Safety, 2019Co-Authors: Narsimha Adimalla, Hui QianAbstract:Abstract An effort has been made to understand the groundwater quality of Nanganur Region for drinking purpose utilizing water quality index (WQI). Nitrate contamination in groundwater was assessed and the associated health risks to rural populations were estimated for different age groups, infants, children and adults in the agricultural Region of Nanganur, South India, where residents rely on only groundwater for drinking use. Groundwater was slightly alkaline and moderately hard. The concentration of nitrate in the groundwater ranged from 25 to 198 mg/L, with a mean of 66.14 mg/L, and 61% of groundwater samples exceeded the World Health Organization (WHO) safe limit of 50 mg/L. The WQI values ranged from 92 to 295, with an average of 153, and about 86% of groundwater samples were poor quality for drinking uses. Results showed that the non-carcinogenic health risk for adults ranged from 6.0E-01 to 4.8E+00, for children 8.1E-01 to 6.4E+00, and for infants 9.4E-01 to 7.4E+00, respectively. Health risk caused by excessive intake of nitrate contaminated groundwater for children and infants were 1.15 and 1.75 times larger than that for adults, which suggested that health risk degree of infants have greater health risk than children and adults in the Study Region. The order of nitrate contribution to non-carcinogenic health risk among the studied age groups was infants > children > adults. Therefore, health risk reduction measures should be implemented to reduce exposure to nitrate contaminated drinking water in the Study Region.
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groundwater quality for drinking and irrigation purposes and potential health risks assessment a case Study from semi arid Region of south india
Exposure and Health, 2019Co-Authors: Narsimha AdimallaAbstract:To determine the groundwater quality in the rapidly urbanizing Region of Telangana State, South India, 194 groundwater samples were collected and analyzed for evaluating the groundwater quality using a geographic information system (GIS) technique. Cations, viz., calcium, magnesium, sodium, potassium; and anions such as bicarbonate, carbonate, chloride, nitrate, sulfate, and fluoride were analyzed using standard procedures. The nitrate concentrations varied from 4 to 440 mg/L, with a mean of 73 mg/L. It is noticed that 48% of the groundwater samples showed nitrate concentrations higher than the maximum permissible limit recommended by World Health Organization (WHO) and Bureau of Indian Standards. The high fluoride concentrations in about 57% of the samples exceeded the maximum permissible limit of 1.5 mg/L. High fluoride concentrations are attributed to geogenic source i.e., rock–water interactions with fluorine-bearing minerals present in the granites of the Study Region. Interpretation of chemistry using Piper diagram indicated that Ca2+–Mg2+–Cl−, Ca2+–Na+–HCO3− and Ca2+–HCO3− were the most predominant water types in the Study Region. The data plotted in the US Salinity Laboratory diagram which revealed that most of the samples fell in the category of C2S2 and C2S3, indicated that the groundwater suitable for irrigation purposes. In additional, health risk assessments were performed and evaluated using the Unites States Environmental Protection Agency (US EPA), to determine the risk of noncarcinogenic disease due to fluoride and nitrate in drinking water. Ingestion health risks were estimated for adults (females and males) and children. Results indicated that children were more exposed to health risk, due to intake of high contaminated drinking water with respective of nitrate and fluoride in the Study area.
Ling Chen - One of the best experts on this subject based on the ideXlab platform.
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crustal structure in the middle southern segments of the tanlu fault zone and adjacent Regions constrained by multifrequency receiver function and surface wave data
Physics of the Earth and Planetary Interiors, 2020Co-Authors: Zigen Wei, Risheng Chu, Ling ChenAbstract:Abstract We successively adopt H-k stacking of receiver functions (RFs) and joint inversion of RF and surface wave dispersion with Gaussian factors of 1.0, 2.0 and 3.0 to invert the crustal thickness (H), average Vp/Vs ratio (k) and S-wave velocity beneath 146 broadband seismic stations in the middle-southern segments of the Tanlu Fault Zone (TLFZ) and adjacent Regions. These observations, together with previous geologic and geophysical studies, are further used to investigate Phanerozoic tectonic evolution in the Study Region and the seismogenic environment of the Tancheng Ms 8.5 earthquake. Our results show that the Moho depth and k generally range from 25 to 38 km and 1.65–1.95, respectively. The Study Region is roughly divided into three parts with different crustal structures from north to south, based on the Cretaceous Tiefogou fault and Triassic Lu'an fault and their extensional profiles, which may reflect different responses to the westward subduction of the Paleo-Pacific and Pacific Plates in the Mesozoic-Cenozoic. In addition to the observed uplifted Moho, high k and vertically alternating high-/low-velocity layers, lateral variations in S-wave velocity and junctions of multiple faults are imaged beneath the Tancheng earthquake zone, which may also contribute to the occurrence of strong earthquakes.
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crust mantle structure difference across the gravity gradient zone in north china craton seismic image of the thinned continental crust
Physics of the Earth and Planetary Interiors, 2006Co-Authors: Tianyu Zheng, Ling Chen, Liang Zhao, Weiwei XuAbstract:The Archean North China Craton (NCC) has been tectonically modified and lost its thick lithospheric keel during the Mesozoic and Cenozoic. The processes and mechanisms of the lithospheric modification and its appearance in and the relation between different subRegions of the NCC are still poorly understood. Seismic data from 45 stations along a 470-km long profile cross the Bohai Bay Basin (BBB) and the Taihangshan Mountain Range (TMR) in the NCC were employed to construct a coherent structural image of the crust and uppermost mantle. An integrated receiver function imaging technique combining the common conversion point stacking approach with waveform inversion and forward modeling was proposed to extract the structural information beneath the Study Region. Modeling of Bouguer gravity anomalies was also applied to constrain the density distribution. The imaging result reveals distinct structural features between the mountain range and the basin area, and presents a picture of uneven crust thinning within the Study Region. In the east BBB the crust is significantly thinned due mainly to the reduction in the thickness of the lower crust including the crust–mantle transition zone, by up to ∼12 km. The west TMR, in contrast, is characterized by a relatively thick lower crust of ∼20 km. The teleseismic waveform data and the gravity observation suggest a thicker crust and a buoyant mantle lithosphere beneath the TMR compared with the BBB. The contrasting crustal structural features appear coupled with the lithospheric processes and possibly reflect that different tectonic mechanisms and deformation regimes dominated the evolution of the two Regions. The North-South Gravity Lineament, lying between the TMR and BBB, might represent a deep intra-continental boundary separating the NCC into topographically and tectonically different Regions.
Kaczka Ryszard - One of the best experts on this subject based on the ideXlab platform.
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Tree growth influenced by warming winter climate and summer moisture availability in northern temperate forests
2020Co-Authors: Harvey Jill, Smiljanić Marko, Scharnweber Tobias, Buras Allan, Cedro Anna, Cruz Garcia Roberto, Drobyshev Igor, Janecka Karolina, Jansons Aris, Kaczka RyszardAbstract:The role of future forests in global biogeochemical cycles will depend on how different tree species respond to climate. Interpreting the response of forest growth to climate change requires an understanding of the temporal and spatial patterns of seasonal climatic influences on the growth of common tree species. We constructed a new network of 310 tree‐ring width chronologies from three common tree species (Quercus robur , Pinus sylvestris and Fagus sylvatica ) collected for different ecological, management and climate purposes in the south Baltic Sea Region at the border of three bioclimatic zones (temperate continental, oceanic, southern boreal). The major climate factors (temperature, precipitation, drought) affecting tree growth at monthly and seasonal scales were identified. Our analysis documents that 20th century Scots pine and deciduous species growth is generally controlled by different climate parameters, and that summer moisture availability is increasingly important for the growth of deciduous species examined. We report changes in the influence of winter climate variables over the last decades, where a decreasing influence of late winter temperature on deciduous tree growth and an increasing influence of winter temperature on Scots pine growth was found. By comparing climate–growth responses for the 1943–1972 and 1973–2002 periods and characterizing site‐level growth response stability, a descriptive application of spatial segregation analysis distinguished sites with stable responses to dominant climate parameters (northeast of the Study Region), and sites that collectively showed unstable responses to winter climate (southeast of the Study Region). The findings presented here highlight the temporally unstable and nonuniform responses of tree growth to climate variability, and that there are geographical coherent Regions where these changes are similar. Considering continued climate change in the future, our results provide important Regional perspectives on recent broad‐scale climate–growth relationships for trees across the temperate to boreal forest transition around the south Baltic Sea
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Tree growth influenced by warming winter climate and summer moisture availability in northern temperate forests
'Wiley', 2020Co-Authors: Harvey, Jill E, Smiljanić Marko, Scharnweber Tobias, Buras Allan, Cedro Anna, Cruz Garcia Roberto, Drobyshev Igor, Janecka Karolina, Jansons Āris, Kaczka RyszardAbstract:Taisyta puslap. ir issThe role of future forests in global biogeochemical cycles will depend on how different tree species respond to climate. Interpreting the response of forest growth to climate change requires an understanding of the temporal and spatial patterns of seasonal climatic influences on the growth of common tree species. We constructed a new network of 310 tree-ring width chronologies from three common tree species (Quercus robur, Pinus sylvestris and Fagus sylvatica) collected for different ecological, management and climate purposes in the south Baltic Sea Region at the border of three bioclimatic zones (temperate continental, oceanic, southern boreal). The major climate factors (temperature, precipitation, drought) affecting tree growth at monthly and seasonal scales were identified. Our analysis documents that 20th century Scots pine and deciduous species growth is generally controlled by different climate parameters, and that summer moisture availability is increasingly important for the growth of deciduous species examined. We report changes in the influence of winter climate variables over the last decades, where a decreasing influence of late winter temperature on deciduous tree growth and an increasing influence of winter temperature on Scots pine growth was found. By comparing climate–growth responses for the 1943–1972 and 1973–2002 periods and characterizing site-level growth response stability, a descriptive application of spatial segregation analysis distinguished sites with stable responses to dominant climate parameters (northeast of the Study Region), and sites that collectively showed unstable responses to winter climate (southeast of the Study Region). The findings presented here highlight the temporally unstable and nonuniform responses of tree growth to climate variability, and that there are geo-graphical coherent Regions where these changes are similar.[...]Aplinkos tyrimų centrasVytauto Didžiojo universiteta
Hui Qian - One of the best experts on this subject based on the ideXlab platform.
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groundwater quality evaluation using water quality index wqi for drinking purposes and human health risk hhr assessment in an agricultural Region of nanganur south india
Ecotoxicology and Environmental Safety, 2019Co-Authors: Narsimha Adimalla, Hui QianAbstract:Abstract An effort has been made to understand the groundwater quality of Nanganur Region for drinking purpose utilizing water quality index (WQI). Nitrate contamination in groundwater was assessed and the associated health risks to rural populations were estimated for different age groups, infants, children and adults in the agricultural Region of Nanganur, South India, where residents rely on only groundwater for drinking use. Groundwater was slightly alkaline and moderately hard. The concentration of nitrate in the groundwater ranged from 25 to 198 mg/L, with a mean of 66.14 mg/L, and 61% of groundwater samples exceeded the World Health Organization (WHO) safe limit of 50 mg/L. The WQI values ranged from 92 to 295, with an average of 153, and about 86% of groundwater samples were poor quality for drinking uses. Results showed that the non-carcinogenic health risk for adults ranged from 6.0E-01 to 4.8E+00, for children 8.1E-01 to 6.4E+00, and for infants 9.4E-01 to 7.4E+00, respectively. Health risk caused by excessive intake of nitrate contaminated groundwater for children and infants were 1.15 and 1.75 times larger than that for adults, which suggested that health risk degree of infants have greater health risk than children and adults in the Study Region. The order of nitrate contribution to non-carcinogenic health risk among the studied age groups was infants > children > adults. Therefore, health risk reduction measures should be implemented to reduce exposure to nitrate contaminated drinking water in the Study Region.
Robert P Anderson - One of the best experts on this subject based on the ideXlab platform.
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the effect of the extent of the Study Region on gis models of species geographic distributions and estimates of niche evolution preliminary tests with montane rodents genus nephelomys in venezuela
Journal of Biogeography, 2010Co-Authors: Robert P Anderson, Ali RazaAbstract:Aim Various techniques model a species’ niche and potential distribution by comparing the environmental conditions of occurrence localities with those of the overall Study Region (via a background or pseudoabsence sample). Here, we examine how changes in the extent of the Study Region (ignored or under-appreciated in most studies) affect models of two rodents, Nephelomys caracolus and Nephelomys meridensis. Location North-central South America. Methods We used Maxent to model the species' potential distributions via two methods of defining the Study Region. In Method 1 (typical of most studies to date), we calibrated the model in a large Study Region that included the ranges of both species. In Method 2, we calibrated the model using a smaller Study Region surrounding the localities of the focal species, and then applied it to the larger Region. Because the Study Region of Method 1 is likely to include areas of suitable conditions that are unoccupied because of dispersal limitations and/or biotic interactions, this approach is prone to overfitting to conditions found near the occupied localities. In contrast, Method 2 should avoid such problems but may require further assumptions (‘clamping’ in Maxent) to make predictions for areas with environmental conditions beyond those found in the smaller Study Region. For each method, we calculated several measures of geographic interpredictivity between predictions for the species (cross-species AUC, cross-species omission rate, and proportional geographic overlap). Results Compared with Method 1, Method 2 revealed a larger predicted area for each species, less concentrated around known localities (especially for N. caracolus). It also led to higher cross-species AUC values, lower cross-species omission rates and higher proportions of geographic overlap. Clamping was minimal and occurred primarily in Regions unlikely to be suitable. Main conclusions Method 2 led to more realistic predictions and higher estimates of niche conservatism. Conclusions reached by many studies depend on the selection of an appropriate Study Region. Although detailed information regarding dispersal limitations and/or biotic interactions will typically be difficult to obtain, consideration of coarse distributional patterns, topography and vegetational zones often should permit delimitation of a much more reasonable Study Region than the extremely large ones currently in common use.
