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1.
Environ Monit Assess ; 195(10): 1188, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37698767

RESUMO

In the Awash River basin (Ethiopia), massive urbanization and industrialization, driven by rapid development and human settlement, are detrimental to the environment and human health as pollutants such as heavy metals (HMs) find their way into water bodies without proper treatment. The purpose of this study was to assess the HMs content and pollution sources within the basin. In this context, a total of 205 samples were collected from 21 surface water sampling stations. Heavy metal concentrations were measured using the Perkin Elmer NexION 350 ICP-MS with inductively coupled plasma. Findings demonstrate that high levels of HMs, such as Al, Mn, Mo, As, V, Fe, and Ba were exhibited with the value of 1257 µg/L, 626.8 µg/L, 116.7 µg/L, 61.2 µg/L, 100.5 µg/L, 1082.7 µg/L, and 211.7 µg/L, respectively. Among 20 HMs analyzed, 20% of the parameters within the study area were above the WHO limit for drinking water; Al (157 µg/L), V (100.5 µg/L), Fe (1082.7 µg/L), Mn (626.8 µg/L), and Mo (103.8 µg/L) were exhibited at sites along the river system. Likewise, 57% of water samples showed high values of As at many stations down the river systems. In particular, high HM concentrations seen in the upper Awash are primarily controlled by anthropogenic activities such as untreated industrial, agricultural, and domestic discharges, while the high HM concentrations in the middle Awash samples were likely due to the influence from the Lake Beseka that has high HM concentrations due to geological process. In conclusion, securing potable water for the rapidly increasing population in Addis Ababa and in the watersheds of Awash is unsafe to sustain the environment and the human health.


Assuntos
Arsênio , Metais Pesados , Humanos , Molibdênio , Efeitos Antropogênicos , Lagos , Rios , Etiópia , Monitoramento Ambiental , Água
2.
Heliyon ; 9(5): e15832, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37215855

RESUMO

Increasing urbanization and industrialization are impacting on water quality globally. In the Awash River basin, Ethiopia, these drivers are impacting on water quality with further impacts created due to changes in water management releasing geogenic contaminants. The resulting water quality has potential to cause significant ecological and human health impacts. The physicochemical and heavy metals saptio-temporal variability and their associated risks to human health and ecology were assessed across twenty sampling stations in the Awash River basin. Over twenty-two physicochemical and ten heavy metals parameters were analyzed using different instruments including inductively coupled plasma mass spectrometer (ICP-MS). Elevated levels of heavy metals (As, V, Mo, Mn, and Fe) were detected in the surface water, surpassing the drinking water quality standards set by the World Health Organization (WHO). Seasonal variation was evident with peak concentration of As, Ni, Hg, and Cr were recorded in the dry season. A water quality index, hazard quotient, hazard index, heavy metal pollution index and heavy metal evaluation index were formulated to assess the potential risks to both human health and the environment. The highest values of heavy metal pollution index (HPI) above the threshold (>100) were observed in stations at Lake Beseka with HPI values ranged from 105 to 177. Similarly, the highest values of the heavy metals evaluation index (HEI) were observed in stations situated at cluster 3. The evaluation of health risk that is not related to cancer through hazard quotient demonstrated that in the case of both dermal and ingestion contact, cluster C3 > C1 > C4 > C2 and C3 > C4 > C2 > C1 were observed in children and adults, respectively. Overall, measures to reduce potential pollution risks must be taken in accordance with the standards in the river basin. Nevertheless, further research on the toxicity of heavy metals that pose risks to human health is also necessary.

3.
J Strength Cond Res ; 37(2): 265-269, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36026487

RESUMO

ABSTRACT: Christian, JR, Gothart, SE, Graham, HK, Barganier, KD, and Whitehead, PN. Analysis of the activation of upper-extremity muscles during various chest press modalities. J Strength Cond Res 37(2): 265-269, 2023-The most effective way to increase muscular strength is through the implementation of resistance training programs. The purpose of this study was to determine the level of muscle activation of the anterior deltoid (AD), medial deltoid (MD), and pectoralis major (PM) during various bench press scenarios. Twenty subjects (10 male and 10 female subjects; age, 24.0 ± 3.0 years) with a minimum of 1 year of resistance training were recruited to participate. Six surface electromyographical sensors were placed bilaterally on the targeted muscles. Subjects performed a 1 repetition maximum (1RM) of dumbbell (DB) and barbell (BB) flat bench press across 2 sessions followed by 6 repetitions at an incline, flat, and decline position at a submaximal 70% 1RM BB and DB. Mean peak values for muscle activation were analyzed for each variation. A repeated-measures 1-way analysis of variance was used to compare muscle activation patterns across conditions. Significance was set at p ≤ 0.05. Activation of AD was significantly higher during incline BB compared with decline BB and decline DB ( p ≤ 0.019). Activation of MD was significantly lower than that of AD across all modalities ( p ≤ 0.040). Activation of PM was significantly lower during incline DB compared with decline DB ( p = 0.011). Differences among AD and PM may have been the result of the stability stipulation variations between DB or BB and the large biacromial breadth requirement. Lack of differentiation of muscle fibers within the PM during sensor placement could have led to lesser muscle activation recordings during decline. As significance was evident for PM when comparing genders ( p ≤ 0.021), and no significance was found among AD or MD, it can be inferred that the larger amounts of adipose tissue in the female subjects caused irregularities in the PM data.


Assuntos
Músculo Esquelético , Treinamento Resistido , Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Músculo Esquelético/fisiologia , Eletromiografia , Músculos Peitorais/fisiologia , Extremidade Superior , Força Muscular/fisiologia , Levantamento de Peso/fisiologia
4.
Artigo em Inglês | MEDLINE | ID: mdl-36078215

RESUMO

The use of facial coverings has been amplified during the COVID-19 pandemic as a means to minimize the spread of disease. However, facial coverings may impede ventilation during high-intensity activity, leading to a reduction in cardiopulmonary exercise capacity. Thus, the purpose of this study was to determine the acute impact of different facial coverings on exercise performance in college-aged individuals during a 300-yard shuttle. It was hypothesized that the lowest heart rate (HR), completion time (CT), and rate of perceived exertion (RPE) would occur with no mask. Furthermore, it was hypothesized the SHEMA97 mask would have lower HR, CT, and RPE compared to surgical and fabric masks. Results showed the use of the fabric mask resulted in significantly higher HR compared to no mask (p = 0.006). The SHEMA97 mask resulted in faster CT and lower RPE compared to both the fabric and surgical masks (p < 0.001). All mask conditions yielded significantly higher levels of perceived discomfort than wearing no mask (p < 0.05). While the use of facial coverings can help prevent the spread of disease, their use during exercise may pose limitations to performance; however, the ability of the SHEMA97 to provide minimal changes to CT and RPE provides a promising option.


Assuntos
COVID-19 , Pandemias , Adulto , Anaerobiose , Exercício Físico , Humanos , Máscaras , Pandemias/prevenção & controle , Adulto Jovem
5.
J Strength Cond Res ; 36(12): 3468-3472, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32881841

RESUMO

ABSTRACT: Conners, RT, Whitehead, PN, Dodds, FT, Schott, KD, and Quick, MC. Validation of the polar team pro system for sprint speed with ice hockey players. J Strength Cond Res 36(12): 3468-3472, 2022-Commercially available player tracking sensors such as the Polar Team Pro system (PTPS) have been used to monitor athlete performance. Use during ice hockey practices and games has resulted in seemingly plausible and valid values for internal metrics (heart rate); however, external metrics (distance, speed, and acceleration) seem sporadic and counterintuitive. To determine the validity of the PTPS for measuring sprint speed with collegiate hockey players, 15 NCAA Division I male athletes (21.86 ± 1.04 years, 175.86 ± 6.78 cm, 80.58 ± 4.44 kg) participated in the study. Subjects wore a PTPS strap, at the level of the xiphoid process, and performed 2 sprints of 15.24 m (blue line to blue line) and 35.05 m (red line to the far blue line) in 3 conditions: indoor ice skating, indoor running, and outdoor running. Timing gates (TG) were used to determine sprint times, which allowed for manual calculation of speed. Speed values from the PTPS and TG were compared using paired-samples t -tests, and an alpha level of 0.05, 2-sided, was set a priori as a significance level. For indoor ice skating, PTPS significantly underestimated speeds at both distances ( p < 0.001). However, PTPS significantly overestimated speeds for indoor and outdoor sprints at both distances ( p ≤ 0.001). The PTPS is not accurate for measuring short-distance linear sprint speed or linear sprint speed during indoor ice skating. The inconsistency in speed values needs to be taken into consideration when using the system for science-based training because inaccurate speed values may negatively affect other external performance metrics provided by PTPS.


Assuntos
Desempenho Atlético , Hóquei , Corrida , Patinação , Masculino , Humanos , Hóquei/fisiologia , Patinação/fisiologia , Desempenho Atlético/fisiologia , Aceleração
6.
Sci Total Environ ; 816: 151638, 2022 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-34774956

RESUMO

In contrast to marine ecosystems, the toxicity impact of microplastics in freshwater environments is poorly understood. This contribution reviews the literature on the range of effects of microplastics across and between trophic levels within the freshwater environment, including biofilms, macrophytes, phytoplankton, invertebrates, fish and amphibians. While there is supporting evidence for toxicity in some species e.g. growth reduction for photoautotrophs, increased mortality for some invertebrates, genetic changes in amphibians, and cell internalization of microplastics and nanoplastics in fish; other studies show that it is uncertain whether microplastics can have detrimental long-term impacts on ecosystems. Some taxa have yet to be studied e.g. benthic diatoms, while only 12% of publications on microplastics in freshwater, demonstrate trophic transfer in foodwebs. The fact that just 2% of publications focus on microplastics colonized by biofilms is hugely concerning given the cascading detrimental effects this could have on freshwater ecosystem function. Multiple additional stressors including environmental change (temperature rises and invasive species) and contaminants of anthropogenic origin (antibiotics, metals, pesticides and endocrine disruptors) will likely exacerbate negative interactions between microplastics and freshwater organisms, with potentially significant damaging consequences to freshwater ecosystems and foodwebs.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Biota , Ecossistema , Monitoramento Ambiental , Água Doce , Plásticos/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
7.
Children (Basel) ; 8(8)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34438581

RESUMO

Preventative measures taken worldwide to decrease the transmission of COVID-19 have had a tremendous impact on youth. Following social restrictions, youth with and without physical disabilities are engaging in less physical activity, more increased sedentary behavior, and poor sleep habits. Specifically, youth wheelchair users (YWU) are likely disproportionately affected by COVID- 19 and have a higher risk of contraction due to underlying comorbidities. While we cannot control all of the negative long-term implications of COVID-19 for YWU, participation in positive 24-h activity behaviors can decrease chronic disease risk and the likelihood of long-term complications resulting from infection. This commentary is to extend the discourse on the importance of 24-h activity behaviors by focusing on YWU. Specifically, we discuss the importance of chronic disease prevention, provide a brief overview of 24-h activity behaviors, and outline some of the lessons that can be learned from the COVID-19 pandemic.

8.
J Biomech ; 124: 110553, 2021 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-34161842

RESUMO

Aquatic therapy for rehabilitation can be performed in a variety of environments, which can vary from a traditional swimming pool to a self-contained underwater treadmill. While kinematic analysis has been performed in large volume swimming pools using specific underwater motion capture systems, researchers may only have access to a land-based motion-capture system, which is not waterproof. Additionally, underwater motion capture systems may not fit within the confines of a smaller underwater treadmill. Thus, the purpose of this study was to design and analyze methodology to quantify lower limb kinematics during an aquatic treadmill session, using a land-based motion capture system. Kinematics of lower limb motion at different speeds was studied while walking on an underwater treadmill in comparison to walking on the same treadmill without water (empty tank). The effects of the presence of water on walking kinematics was analyzed and interpreted using parametric and non-parametric testing procedures. The results suggest significant influences of speed on knee and ankle angles (p < 0.05) in both dryland and aquatic scenarios. Knee and ankle angle measures revealed no significant differences between the dryland and water treadmill scenarios (p > 0.05). The increased time requirement in water for the full gait cycle found in this study indicates influence of resistive effects. This finding can be especially suited for muscle strengthening and stabilizing treatments for lower limbs. Also, a framework was developed to realize a potential methodology to use land-based motion capture cameras to successfully analyze the kinematics of gait in constrained aquatic volumes.


Assuntos
Marcha , Caminhada , Fenômenos Biomecânicos , Teste de Esforço , Movimento (Física)
9.
Int J Exerc Sci ; 14(4): 230-238, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34055165

RESUMO

One method to measure body composition that is gaining popularity is the BodyMetrix™, which uses A-mode ultrasound. A-mode ultrasound, when used with the BodyMetrix™, has been found to be a reliable and a cost-effective tool for measuring overall body fat percentage. Furthermore, the portability and short duration testing features of the BodyMetrix™, allows for testing of a large group of athletes inside or outside of a clinical setting. Despite these advantages, research regarding the BodyMetrix™ is limited and has primarily focused on the seven-site testing technique. However, the three-site technique allows for faster testing and a reduction of time needed to test an entire team or multiple sports teams. Thus, the purpose of this study was to compare the three-site and seven-site methods using the BodyMetrix™ to determine body fat percentage in female collegiate athletes. It was hypothesized that body fat percentage determined via the seven-site method would be different from those obtained by three-site measurement technique. Study participants included 40 National Collegiate Athletic Association (NCAA) Division-II female athletes from volleyball, soccer, and softball teams. The Jackson Pollock three-site (thigh, suprailiac, triceps) and seven-site (thigh, suprailiac, triceps, abdominal, subscapular, chest, and axilla) equations were used to determine body fat percentage values. The time required to perform the three-site and seven-site measurements were also recorded. A paired samples t-test was used to assess if there was a difference between the three-site and the seven-site body fat percentage measurements with the use of the BodyMetrix™ . The three-site method (23.21 ± 3.61) was significantly lower (p < 0.001) compared to the seven- site method (25.75 ± 4.39). On average, the three-site technique took 2 minutes and 13 seconds less than the seven-site technique.

10.
Sci Total Environ ; 755(Pt 1): 142468, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33032131

RESUMO

The livelihoods of millions of people living in the world's deltas are deeply interconnected with the sediment dynamics of these deltas. In particular a sustainable supply of fluvial sediments from upstream is critical for ensuring the fertility of delta soils and for promoting sediment deposition that can offset rising sea levels. Yet, in many large river catchments this supply of sediment is being threatened by the planned construction of large dams. In this study, we apply the INCA hydrological and sediment model to the Mekong River catchment in South East Asia. The aim is to assess the impact of several large dams (both existing and planned) on the suspended sediment fluxes of the river. We force the INCA model with a climate model to assess the interplay of changing climate and sediment trapping caused by dam construction. The results show that historical sediment flux declines are mostly caused by dams built in PR China and that sediment trapping will increase in the future due to the construction of new dams in PDR Lao and Cambodia. If all dams that are currently planned for the next two decades are built, they will induce a decline of suspended sediment flux of 50% (47-53% 90% confidence interval (90%CI)) compared to current levels (99 Mt/year at the delta apex), with potentially damaging consequences for local livelihoods and ecosystems.

11.
Sci Rep ; 10(1): 14408, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32873881

RESUMO

Quantitatively determining in vivo achievable drug concentrations in targeted organs of animal models and subsequent target engagement confirmation is a challenge to drug discovery and translation due to lack of bioassay technologies that can discriminate drug binding with different mechanisms. We have developed a multiplexed and high-throughput method to quantify drug distribution in tissues by integrating high content screening (HCS) with U-Net based deep learning (DL) image analysis models. This technology combination allowed direct visualization and quantification of biologics drug binding in targeted tissues with cellular resolution, thus enabling biologists to objectively determine drug binding kinetics.


Assuntos
Caderinas/imunologia , Carbocianinas , Aprendizado Profundo , Corantes Fluorescentes , Ensaios de Triagem em Larga Escala/métodos , Processamento de Imagem Assistida por Computador/métodos , Imunoconjugados/metabolismo , Animais , Caderinas/metabolismo , Colo/metabolismo , Descoberta de Drogas/métodos , Intestino Delgado/metabolismo , Camundongos , Distribuição Tecidual
12.
J Biomech ; 89: 139-142, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31030892

RESUMO

While the capabilities of land-based motion capture systems in biomechanical applications have been previously reported, the possibility of using motion tracking systems externally to reconstruct markers submerged inside an aquatic environment has been under explored. This study assesses the ability of a motion capture system (Vicon T40s) arranged externally to track a retro-reflective marker inside a glass tank filled with water and without water. The reflective tape used for marker creation in this study was of Safety of Life at Sea (SOLAS) grade as the conventional marker loses its reflective properties when submerged. The overall trueness calculated based on the mean marker distance errors, varied between 0.257 mm and 0.290 mm in different mediums (air, glass and water). The overall precision calculated based on mean standard deviation of mean marker distances at different locations varied between 0.046 mm and 0.360 mm in different mediums. Our results suggest, that there is no significant influence of the presence of water on the overall static accuracy of the marker center distances when markers were made of SOLAS grade reflective tape. Using optical motion tracking systems for evaluating locomotion in aquatic environment can help to better understand the effects of aquatic therapy in clinical rehabilitation, especially in scenarios that involve equipment, such as an underwater treadmill which generally have constrained capture volumes for motion capture.


Assuntos
Movimento (Física) , Dispositivos Ópticos , Água , Algoritmos , Fenômenos Mecânicos
13.
J Strength Cond Res ; 33(4): 1035-1042, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30908458

RESUMO

Whitehead, PN, Conners, RT, and Shimizu, TS. The effect of in-season demands on lower-body power and fatigue in male collegiate hockey players. J Strength Cond Res 33(4): 1035-1042, 2019-The purpose of this study was to determine the effect of in-season demands, such as games, travel, and the subsequent fatigue related to these demands, on lower-body power (LBP) in collegiate hockey players. Two jump protocols (countermovement and squat jumps) were used to calculate LBP. Twenty-seven NCAA (National Collegiate Athletic Association) Division I male hockey players (age, 21.9 ± 1.4 years; height, 176.7 ± 6.5 cm; body mass, 81.4 ± 7.9 kg) participated in the study that spanned 18 weekly sessions. At each session, participants completed an 8-item fatigue questionnaire, which provided a cumulative numerical value for fatigue (total score of fatigue [TSF]), before performing maximal jumps on a contact mat. General linear modeling was conducted to compare dependent variables (jump height, relative LBP, TSF) across weekly sessions. Pearson product-moment correlation coefficients were calculated to examine the relationship between jump height and LBP across the jump protocols, as well as to examine the relationship of TSF with all measured variables. Jump height and LBP declined throughout the season with greater effect of travel observed following the longest travel sequence (p ≤ 0.05; η ≥ 0.60). Differences in TSF were observed from baseline (p ≤ 0.037), and a large effect was seen for away trips that included air travel (d ≥ 1.35). Total score of fatigue had a negative correlation with jump height and power during both jumps (r ≤ -0.742; p < 0.001). In conclusion, the in-season demands of ice hockey resulted in significant reductions in LBP throughout a hockey season, and the 8-item fatigue questionnaire is a sensitive tool reflective of athletic performance measures.


Assuntos
Desempenho Atlético/fisiologia , Fadiga/fisiopatologia , Hóquei/fisiologia , Extremidade Inferior/fisiopatologia , Viagem , Teste de Esforço , Humanos , Estudos Longitudinais , Masculino , Força Muscular , Inquéritos e Questionários , Adulto Jovem
14.
Zootaxa ; 4555(4): 588-594, 2019 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-30790940

RESUMO

The Oriental burrower bug Macroscytus subaeneus (Dallas, 1851) (Hemiptera: Heteroptera: Cydnidae: Cydninae), presently known only from single localities in Flores (Indonesia), the Philippines and Thailand, is recorded from the United Kingdom (hereafter U.K.). A single female specimen was collected on the semi-rural edge of Bath city by a Starling (Sturnus vulgaris L.) and taken to its nest from which it was retrieved during 2015. The specimen is illustrated and its diagnostic characters are provided. We hypothesize that this specimen could have been imported with a shipping container from Thailand.


Assuntos
Heterópteros , Animais , Europa (Continente) , Feminino , Indonésia , Filipinas , Tailândia , Reino Unido
15.
Sci Total Environ ; 646: 1459-1467, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30235631

RESUMO

Pharmaceuticals, personal care products (PPCPs), and artificial sweeteners (ASWs) are contaminants of emerging concern commonly found in the aquatic environments. In India, studies reporting environmental occurrence of these contaminants are scarce. In this study, we investigated the occurrence and distribution of 15 PPCPs and five ASWs in the river and groundwater (used untreated as drinking water) at several sites along the Ganges River. Based on the measured groundwater concentrations, we estimated the life-long human health risk from exposure to PPCPs through drinking. In addition, we estimated the risk of exposure to PPCPs and ASWs in the river water for aquatic organisms. The sum of detected PPCPs in the river water ranged between 54.7-826 ng/L, with higher concentrations in the severely anthropogenically influenced middle and lower reaches of the Ganges. The highest concentration among the PPCPs in the river water was of caffeine (743 ng/L). The sum of detected ASWs in river water ranged between 0.2-102 ng/L. Similar to PPCPs, the sum of ASWs in the river water was higher in the middle and lower reaches of the Ganges. In groundwater, the sum of detected PPCPs ranged between 34-293 ng/L, whereas of ASWs ranged between 0.5-25 ng/L. Negligible risk for humans was estimated from PPCPs in the drinking groundwater sources along the Ganges River, whereas moderate risks to PPCPs and ASWs (namely: caffeine, sulfamethoxazole, triclocarban, triclosan, and sucralose) were estimated for aquatic organisms in the Ganges River.


Assuntos
Cosméticos/análise , Monitoramento Ambiental , Preparações Farmacêuticas/análise , Edulcorantes/análise , Poluentes Químicos da Água/análise , Água Potável/química , Água Subterrânea/química , Humanos , Índia , Medição de Risco , Rios/química
17.
Sci Total Environ ; 636: 1362-1372, 2018 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-29913597

RESUMO

The Ganga-Brahmaputra-Meghna (GBM) River System, the associated Hooghly River and the Mahanadi River System represent the largest river basins in the world serving a population of over 780 million. The rivers are of vital concern to India and Bangladesh as they provide fresh water for people, agriculture, industry, conservation and support the Delta System in the Bay of Bengal. Future changes in both climate and socio-economics have been investigated to assess whether these will alter river flows and water quality. Climate datasets downscaled from three different Global Climate Models have been used to drive a daily process based flow and water quality model. The results suggest that due to climate change the flows will increase in the monsoon period and also be enhanced in the dry season. However, once socio-economic changes are also considered, increased population, irrigation, water use and industrial development reduce water availability in drought conditions, threatening water supplies and posing a threat to river and coastal ecosystems. This study, as part of the DECCMA (Deltas, vulnerability and Climate Change: Migration and Adaptation) project, also addresses water quality issues, particularly nutrients (N and P) and their transport along the rivers and discharge into the Delta System. Climate will alter flows, increasing flood flows and changing pollution dilution factors in the rivers, as well as other key processes controlling water quality. Socio-economic change will affect water quality, as water diversion strategies, increased population and industrial development alter the water balance and enhance fluxes of nutrients from agriculture, urban centers and atmospheric deposition.

18.
Sci Total Environ ; 637-638: 1069-1080, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29801202

RESUMO

As the scientific consensus concerning global climate change has increased in recent decades, research on potential impacts of climate change on water resources has been given high importance. However in Sub-Saharan Africa, few studies have fully evaluated the potential implications of climate change to their water resource systems. The Volta River is one of the major rivers in Africa covering six riparian countries (mainly Ghana and Burkina Faso). It is a principal water source for approximately 24 million people in the region. The catchment is primarily agricultural providing food supplies to rural areas, demonstrating the classic water, food, energy nexus. In this study an Integrated Catchment Model (INCA) was applied to the whole Volta River system to simulate flow in the rivers and at the outlet of the artificial Lake Volta. High-resolution climate scenarios downscaled from three different Global Climate Models (CNRM-CM5, HadGEM2-ES and CanESM2), have been used to drive the INCA model and to assess changes in flow by 2050s and 2090s under the high climate forcing scenario RCP8.5. Results show that peak flows during the monsoon months could increase into the future. The duration of high flow could become longer compared to the recent condition. In addition, we considered three different socio-economic scenarios. As an example, under the combined impact from climate change from downscaling CNRM-CM5 and medium+ (high economic growth) socio-economic changes, the extreme high flows (Q5) of the Black Volta River are projected to increase 11% and 36% at 2050s and 2090s, respectively. Lake Volta outflow would increase +1% and +5% at 2050s and 2090s, respectively, under the same scenario. The effects of changing socio-economic conditions on flow are minor compared to the climate change impact. These results will provide valuable information assisting future water resource development and adaptive strategies in the Volta Basin.

19.
Sci Total Environ ; 637-638: 907-917, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29763871

RESUMO

Delta systems formed by the deposition of sediments at the mouths of large catchments are vulnerable to sea level rise and other climate change impacts. Deltas often have some of the highest population densities in the world and the Mahanadi Delta in India is one of these, with a population of 39 million. The Mahanadi River is a major river in East Central India and flows through Chattisgarh and Orissa states before discharging into the Bay of Bengal. This study uses an Integrated Catchment Model (INCA) to simulate flow dynamics and water quality (nitrogen and phosphorus) and to analyze the impacts of climate change and socio-economic drivers in the Mahanadi River system. Future flows affected by large population growth, effluent discharge increases and changes in irrigation water demand from changing land uses are assessed under shared socio-economic pathways (SSPs). Model results indicate a significant increase in monsoon flows under the future climates at 2050s (2041-2060) and 2090s (2079-2098) which greatly enhances flood potential. The water availability under low flow conditions will be worsened because of increased water demand from population growth and increased irrigation in the future. Decreased concentrations of nitrogen and phosphorus are expected due to increased flow hence dilution. Socio-economic scenarios have a significant impact on water quality but less impact on the river flow. For example, higher population growth, increased sewage treatment discharges, land use change and enhanced atmospheric deposition would result in the deterioration of water quality, while the upgrade of the sewage treatment works lead to improved water quality. In summary, socio-economic scenarios would change future water quality of the Mahanadi River and alter nutrient fluxes transported into the delta region. This study has serious implications for people's livelihoods in the deltaic area and could impact coastal and Bay of Bengal water ecology.


Assuntos
Mudança Climática , Rios/química , Qualidade da Água , Abastecimento de Água/estatística & dados numéricos , Índia , Fatores Socioeconômicos
20.
Sci Total Environ ; 635: 659-672, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29680757

RESUMO

To better anticipate potential impacts of climate change, diverse information about the future is required, including climate, society and economy, and adaptation and mitigation. To address this need, a global RCP (Representative Concentration Pathways), SSP (Shared Socio-economic Pathways), and SPA (Shared climate Policy Assumptions) (RCP-SSP-SPA) scenario framework has been developed by the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC-AR5). Application of this full global framework at sub-national scales introduces two key challenges: added complexity in capturing the multiple dimensions of change, and issues of scale. Perhaps for this reason, there are few such applications of this new framework. Here, we present an integrated multi-scale hybrid scenario approach that combines both expert-based and participatory methods. The framework has been developed and applied within the DECCMA1 project with the purpose of exploring migration and adaptation in three deltas across West Africa and South Asia: (i) the Volta delta (Ghana), (ii) the Mahanadi delta (India), and (iii) the Ganges-Brahmaputra-Meghna (GBM) delta (Bangladesh/India). Using a climate scenario that encompasses a wide range of impacts (RCP8.5) combined with three SSP-based socio-economic scenarios (SSP2, SSP3, SSP5), we generate highly divergent and challenging scenario contexts across multiple scales against which robustness of the human and natural systems within the deltas are tested. In addition, we consider four distinct adaptation policy trajectories: Minimum intervention, Economic capacity expansion, System efficiency enhancement, and System restructuring, which describe alternative future bundles of adaptation actions/measures under different socio-economic trajectories. The paper highlights the importance of multi-scale (combined top-down and bottom-up) and participatory (joint expert-stakeholder) scenario methods for addressing uncertainty in adaptation decision-making. The framework facilitates improved integrated assessments of the potential impacts and plausible adaptation policy choices (including migration) under uncertain future changing conditions. The concept, methods, and processes presented are transferable to other sub-national socio-ecological settings with multi-scale challenges.

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