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1.
J Environ Manage ; 270: 110809, 2020 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-32721293

RESUMEN

Understanding how households make use of adaptive and resilient coping strategies are steps in the right direction of dealing with disaster risks and extreme weather and climate events. In the recent past, safety nets programs have been quickly scaled up to respond to some of these climate-related and other types of shocks in a bid to improve resilience and restore the productive capacity of households. In Ghana for instance, there has been the flagship Livelihood Empowerment Against Poverty (LEAP) program from which stemmed an ad-hoc cash grant program, Emergency LEAP which is rolled out to victims of natural disasters like floods, storms, and droughts. Based on the above, this paper analyzes the role of the Emergency LEAP in building the adaptive and resilient nature of households against floods. With insights from an extended version of the Protection Motivation Theory (PMT), the paper hypothesizes that relief assistance has a negative impact on the adoption of risk mitigation measures against floods. The study employs both binary and count data models like the Probit, the Poisson, and the Negative Binomial models respectively to establish the impact of such relief assistance on the adaptive behavior of households.The findings reject the null hypothesis; thus, strengthening the argument that relief assistance has a negative influence on the use of resilient coping strategies. Furthermore, the study establishes that experience in floods increases the resilient nature of households. The study concludes that social safety net programs like the emergency LEAP could perform better if given a renewed focus that transcends beyond just cash benefit to including much better long-term interventions like the integration of community-driven development (CDD) programs as well as inducing behavioral change through information access and education.


Asunto(s)
Inundaciones , Pobreza , Adaptación Psicológica , Empoderamiento , Ghana
3.
Water Sci Technol ; 81(6): 1264-1272, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32597412

RESUMEN

Construction of an airport runway makes the impervious area of the airport high, which leads to the deterioration of the water environment and frequent waterlogging disasters. The selection of sponge airport facilities (e.g., pump, multi-functional storage tanks, green roof) to mitigate airport flooding has been a crucial issue in China. This study aims to develop a conceptual rainwater-runoff simulation model, which can take into account the effects of such facilities of a sponge airport. Taking catchment N1 of Beijing Daxing Airport as a case study, SWMM 5.1 was implemented to develop three sponge airport models (one pump, two pumps, combination of pump and multi-functional storage tanks). A sensitivity analysis was carried out to guarantee the robustness of the developed models. A 1-hour rainfall scenario with a 5-year return period was employed on the three sponge airport models. The results showed that the effect rankings of the control strategies on the water depth, volume and peak inflow of catchment N1 were comparable - combined strategies (combination of pump and multi-functional storage tanks) > one pump and two pumps. The conceptual and hydrological models developed in this study can serve as a simulation tool for implementing a real-time rainwater drainage control system in Beijing Daxing Airport.


Asunto(s)
Inundaciones , Movimientos del Agua , Aeropuertos , Beijing , China , Lluvia
4.
Ying Yong Sheng Tai Xue Bao ; 31(3): 1043-1054, 2020 Mar.
Artículo en Chino | MEDLINE | ID: mdl-32538002

RESUMEN

Riparian zones, the critical ecological interfaces between terrestrial and aquatic ecosystems, are species rich habitats. However, riparian zones are seriously threatened by human activities in the world. Riparian invertebrates represent a large proportion of riparian biodiversity, perform various ecological functions, and provide an essential link between aquatic and terrestrial ecosystems. Although many studies have investigated the riparian invertebrate communities, there is lacking a comprehensive summary of maintaining mechanisms underlying riparian invertebrate diversity. This review discussed seven characteristics of riparian zones that might support high riparian invertebrate diversity: flood and drought, nutrient, microhabitat diversity, riparian vegetation, microclimate gradients, food resources and river spatial gradients. Further, we summarized the maintaining mechanisms of riparian invertebrate diversity. Disturbances of periodic flood and drought trigger the reproduction and migration of invertebrates, increase the turnover of invertebrate communities, and create suitable conditions for riparian invertebrates. Adequate nutrients support a high invertebrate diversity by increasing primary productivity of riparian habitats. Elevated microhabitat diversity provides a variety of niche space for specialist riparian invertebrates. Strong microclimate gradients provide complex and diverse habitats and thus facilitate the coexistence of aquatic and terrestrial invertebrates in riparian zones. Cross-ecosystem resource subsidies increase food availability and contribute unique food sources to riparian invertebrates. The differentiation of these factors along river longitudinal and lateral gradients provides conditions for the diversification of riparian invertebrates at a larger scale. Understanding the maintaining mechanisms of riparian invertebrate diversity is important for conservation of riparian biodiversity and integrated management of river ecosystems.


Asunto(s)
Ecosistema , Invertebrados , Animales , Biodiversidad , Inundaciones , Ríos
5.
Ying Yong Sheng Tai Xue Bao ; 31(4): 1223-1232, 2020 Apr.
Artículo en Chino | MEDLINE | ID: mdl-32530197

RESUMEN

Under the background of climate change, the spatial-temporal distribution of precipita-tion in Heilongjiang Province is uneven, and drought and flood frequently change, which is not conducive to the safety of soybean production for the province. To clarify the influence mechanism of drought and flood in the growing season on soybean yield in Heilongjiang Province, we analyzed the time-series characteristics of drought and flood in soybean growing season and its effect on soybean yield in different growth stages, based on data of daily precipitation from 60 meteorological stations during 1961 to 2018 and soybean yield in the same period, with the standardized precipitation index (SPI) as the drought and flood evaluation index. The results showed that, from 1961 to 2018, the influence range of drought in soybean growing season in Heilongjiang Province showed a weak decreasing trend, while that of flood showed a weak increasing trend. In the same period, the intensity of both drought and flood showed a weak increasing trend, with slightly stronger role of flood intensity. The probability of the co-occurrence of drought and flood accounted for 60.3%. The soybean growing season in Heilongjiang Province may become wetter. From 2012 to 2018, the influence range and occurrence intensity of flood were significantly higher than that of drought, six years of the whole or regional flood occurred, in which five years were moderate degrees. The effects of drought and flood on soybean yield differed across regions in soybean growing season. The effect of flood on soybean yield was significantly stronger than that of drought in the Northwest, North and East, and were similar in the Midland, while in the Southwest, South and Southeast, the effect of drought was much greater than that of flood. The fluctuation of soybean yield was closely related to drought and flood during bloom-seed-filling period. Among them, in the Northwest, Southwest, Midland, South and Southeast of Heilongjiang, soybean yield would reach a high level when there was a little bit more precipitation, but the moderate and above-moderate levels of flood would cause the reduction. In the North, the fluctuation of soybean yield was mainly affected by flood, while in the East, the effects of drought and flood on soybean yield were similar.


Asunto(s)
Sequías , Inundaciones , China , Cambio Climático , Estaciones del Año , Soja
6.
J Environ Manage ; 269: 110822, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32561019

RESUMEN

An integrated methodological framework for assessing different flood mitigation measures in urban catchments is presented. The framework comprises hydrologic, hydraulic and economic indices aiming at quantifying the effect of different alternatives regarding flood hazard mitigation. The alternatives evaluated include both conventional drainage solutions and low impact development measures. The conventional drainage solutions were: (i) off-line detention tanks; and (ii) sewer enlargement. The low impact development measures included: (i) green roofs (GR); and (ii) permeable surfaces (PS). Each solution was modeled using SWMM5 with respect to flood reduction effectiveness, and the results were compared to those of the existing condition (i.e., no flood mitigation measures). All the examined solutions were also compared based on their construction and operation and maintenance costs for a typical lifespan (i.e., 30 years). The results of the simulation revealed that both low impact development measures and conventional drainage solutions were highly effective even for storm events with low probability of occurrence. However, sewer enlargement was found to be the best alternative from an economic perspective. Nevertheless, peak at the sewer exit increased and time to peak remained unchanged; as a result, local flooding problems are resolved but downstream flooding problems may be introduced. If other criteria are considered, i.e., traffic obstruction, noise, construction easiness, co-benefits and downstream impacts, low impact development measures become more attractive compared to conventional drainage solutions.


Asunto(s)
Inundaciones , Hidrología , Modelos Teóricos , Lluvia
7.
Sci Total Environ ; 727: 138740, 2020 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-32498193

RESUMEN

With the demand for restoration and future prediction of climate change effects, subtropical peatlands are expected to be subjected to hydrologic regimes with variable duration and frequency of drained and flooded conditions, but knowledge of their interactive effects on soil biogeochemistry and emission of greenhouse gases including nitrous oxide (N2O) is largely limited. The objective of this study was to investigate how the duration and frequency of drainage and flooding events interactively influence soil biogeochemical properties and denitrification and related net N2O production rates following rewetting. Surface soils are susceptible to different hydrologic regimes. Significantly higher pH, extractable organic carbon (ext. OC), ammonium (NH4+-N), denitrification enzyme activity (DEA), but lower nitrate (NO3--N), microbial biomass C and N were observed when the peat soils were under flooded conditions compared to drained conditions. Two-week and four-week drainage or flooding duration did not result in statistically significant differences in soil biogeochemical properties. A 24-week prolonged drainage led to an accumulation of NO3--N and a significantly lower pH. Soil microbial biomass and fungal:bacterial abundance likely increased with the frequency of drainage-flooding cycles. Significant differences in denitrification and net N2O production rates following reflooding were mainly found in the surface soils. Structural equation modeling indicated that hydroperiod and water-filled pore space (WFPS) prior to reflooding is likely to control denitrification and net N2O production through its regulation of NO3--N and activity of microorganisms involved in denitrification while higher drainage-flooding frequency decreases the availability of organic C and NO3--N for denitrification. Our results also suggest high NO3--N and low pH within peat soils caused by prolonged drainage likely leads to a significant N2O emission pulse following reflooding. For peat soils subjected to frequent drainage-flooding cycles, N2O emission pulses following reflooding would decrease with time, attributing to the loss of substrates for denitrification.


Asunto(s)
Suelo , Desnitrificación , Inundaciones , Nitrógeno , Óxido Nitroso
8.
Sci Total Environ ; 724: 138225, 2020 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-32408452

RESUMEN

The competition-to-stress hypothesis suggests that some competitively disadvantaged species are excluded from higher inundation estuaries due to abiotic stress (high flooding level) and from lower inundation estuaries by competition. How abiotic and biotic stress interactions affect plant growth and whether competition intensity and importance are stable along environmental gradients is a controversial subject. We explored the influence of two factors, and we clarified that inundation stress and invasion competition are the main reasons leading to the traits exhibited by target plant Suaeda salsa and population presence changes. Our results indicated that when the flooding height exceeded 13.4 cm, the S. salsa mortality rate was 90%-100%. At the lower flooding heights (<13.4 cm), the S. salsa mortality rate when neighboring plants were present was 77.7%-100%, whereas, without neighbors it was 30.9%-83.7%. The invader Spartina alterniflora inhibited S. salsa plant height by 48%-77%, whereas the S. alterniflora inhibited S. salsa density by 11%-98% and reduced its biomass by 50.5%-90.1%. The changes in competition intensity and importance showed that the S. alterniflora had a distinct impact from the early germinant period to growing period (from May to July), finally stable no differences along the flooding height in the maturity period. At the same flooding level, the analysis of above and belowground competition by S. alterniflora showed that aboveground and belowground competition are the main causes of individual S. salsa inhibition. Our results confirm the competitive stress hypothesis, which is that competition shapes individual traits and population presence in the context of abiotic stress. This conclusion can guide the management and protection of native plants under biological invasion in a stressful environment.


Asunto(s)
Chenopodiaceae , Estuarios , China , Inundaciones , Poaceae , Humedales
9.
Mar Pollut Bull ; 155: 111191, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32469788

RESUMEN

Consequences of a catastrophic flood on the habitat quality and the concurrent responses of the bentho-pelagic community were studied in Cochin estuary, a eutrophic estuary along the southwest coast of India. The episodic flood in 2018 led to a marked decline in the dissolved nutrients and heavy metal concentrations in water and sediments of the estuary. The pre-flood phytoplankton abundance dominated by a bloom-forming species Cerataulina bicornis experienced a significant drop after the flood. Contrarily, zooplankton and macrobenthos responded favorably towards the flood-imposed habitat alterations. Higher susceptibility to heavy metal pollution and increased grazing pressure from gelatinous carnivores restricted the abundance of Copepoda, the dominant zooplankton taxon during pre-flood. The lower heavy metal concentration in the sediment after the flood favored higher macrobenthic abundance and diversity with a conspicuous change in the community structure from opportunistic polychaetes, indicators of pollution to molluscans and crustaceans, indicators of the healthy benthic zones.


Asunto(s)
Metales Pesados/análisis , Contaminantes Químicos del Agua/análisis , Animales , Monitoreo del Ambiente , Estuarios , Inundaciones , Sedimentos Geológicos , India
10.
J Emerg Manag ; 18(3): 205-211, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32441037

RESUMEN

In 2010 and 2017, respectively, the manuscripts Location and Analysis of Emergency Management Point of Dis-tributions (PODS) for Hurricane Ike and Use of Geographical Information System Data For Emergency Management Points of Distribution Analysis With POD Locator 2.0 were published in the Journal of Emergency Management. These manuscripts described the use of the University of Houston POD Locator software to determine the location of Points of Distribution under emergency conditions. This software achieved a 46 percent improvement in POD loca-tions in comparison to those actually selected during the event. However, a limitation of those research efforts was the absence of the potential effects of flood waters as experienced in the Houston Harris County area during Hurri-cane Harvey in 2017. This research effort focuses on the effects of flood water in determining the location of different PODs under these conditions in comparison to the PODs identified by Hurricane Harvey. The results indicate a sta-tistically significant difference at an alpha level of 0.05 between using and not using flood data when determining the location of PODs. The use of flood data also yielded a 46.5 percent in travel distance reduction over the actual 26 POD locations chosen in Ike.


Asunto(s)
Tormentas Ciclónicas , Planificación en Desastres , Equipos y Suministros , Sistemas de Información Geográfica , Urgencias Médicas , Servicio de Urgencia en Hospital , Inundaciones , Humanos , Texas
11.
Water Sci Technol ; 81(4): 679-693, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32460272

RESUMEN

Intense urbanization results in greater soil sealing and a consequent increase in surface runoff. When high soil sealing rates and high slopes are encountered in small catchments, high volume and short duration precipitation events increase the probability of flash floods. This study evaluates the hydrological response of an urban catchment with regard to rainfall-runoff events in the following scenarios: current land use, without a detention basin which has been part of the system since the 1970s, with the maximum soil sealing allowed by legislation, and with green infrastructure implantation in 100%, 50% and 10% of the suitable area. Hydrological modelling was performed using the Storm Water Management Model (SWMM). Six level gauges installed along the length of the stream provided the data used in model calibration and validation. The model calibration process provided adequate results: the average Nash-Sutcliffe coefficient was 0.72, the mean error of peak flow was 11% and the mean error of the runoff volume was 12%. Rainfall based on 2-, 10-, 50- and 100-year events were simulated for each scenario, as well as two observed events. In the scenario without the detention basin, an average elevation of 10% in the peak flow was observed in the catchment outlet. In the scenario with maximum soil sealing, the catchment outlet peak flow increased by 30% on average. On the other hand, in the scenario with green infrastructure implementation in 100%, 50% and 10% of the available areas, the outlet peak flow was reduced by 60%, 30% and 5%, respectively. Results indicated the efficiency of the detention basin to reduce flooding, the importance of green area preservation to reduce peak flows, as well as the catchment potential of green infrastructure implementation and the hydrological benefits that they can provide, increasing infiltration and reducing runoff volume and peak flow.


Asunto(s)
Hidrología , Movimientos del Agua , Brasil , Inundaciones , Modelos Teóricos , Lluvia , Urbanización
12.
J Environ Manage ; 265: 110485, 2020 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-32421551

RESUMEN

Across the world, the flood magnitude is expected to increase as well as the damage caused by their occurrence. In this case, the prediction of areas which are highly susceptible to these phenomena becomes very important for the authorities. The present study is focused on the evaluation of flood potential within Trotuș river basin in Romania using six ensemble models created by the combination of Analytical Hierarchy Process (AHP), Certainty Factor (CF) and Weights of Evidence (WOE) on one hand, and Gradient Boosting Trees (GBT) and Multilayer Perceptron (MLP) on the other hand. A number of 12 flood predictors, 172 flood locations and 172 non-flood locations were used. A percentage of 70% of flood and non-flood locations were used as input in models. From the input data, 70% were used as training sample and 30% as validating sample. The highest accuracy was obtained by the MLP-CF model in terms of both training (0.899) and testing (0.889) samples. A percentage between 21.88% and 36.33% of study area is covered with high and very high flood potential. The results validation, performed through the ROC Curve method, highlights that the MLP-CF model provided the most accurate results.


Asunto(s)
Inundaciones , Redes Neurales de la Computación , Algoritmos , Curva ROC , Rumanía
13.
J Environ Manage ; 268: 110521, 2020 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-32383653

RESUMEN

Due to the influence of buildings on the distribution of flood and their economic and social attributes, 3D spatial information such as the size of buildings and the flooded ratio of buildings relative to their height has an increasing impact on urban flood risk. However, existing flood risk assessment methods mainly use data in 2D and analysis methods are mostly 2D. In this study, flood variation processes were analyzed in the form of 3D dynamic visualization by coupling an urban drainage model and a flood simulation model with 3D visualization methods. By further combining with 3D building models, the 3D spatial information of buildings related to flood was obtained. In order to study the influence of 3D information on flood risk and combine with other multi-source heterogeneous data for integrated analysis, a 3D visualization assessment and analysis method for flood risk, coupled with the projection pursuit-particle swarm optimization algorithm (PP-PSO) was established (3DVAAM-PP-PSO). A case study from Chaohu City, China, was used to demonstrate the method. The results showed that the PP-PSO algorithm can process high-dimensional information and obtain the objective weight of each index. The 3D information from the influenced buildings had an impact on the evaluation results, which needed to be considered. Through the 3D visualization analysis, the overall distribution of flood risk and that around the buildings were obtained in multi-perspectives. The flood risk during different rainfall return periods were analyzed intuitively and comparatively. This study furnishes a novel method for flood risk assessment and analysis by making the most of 3D spatial information.


Asunto(s)
Inundaciones , Imagenología Tridimensional , Algoritmos , China , Ciudades , Medición de Riesgo
14.
Environ Monit Assess ; 192(6): 387, 2020 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-32436015

RESUMEN

Global climate change and human activities aggravate the frequency of flood disasters. Flood risk includes natural flood risk and risk of economic and social disasters, which is displayed intuitively by flood risk zonation maps. In this paper, we take the disaster-causing factors, the disaster environment, the disaster-bearing body, and the disaster prevention and mitigation capability into consideration comprehensively. Eleven influencing indexes including annual maximum 3-day rainfall and rainfall in flood season are selected, and the virtual sown area of crops is innovated. Taking the Huaihe River Basin (HRB) as the research area, the flood risk prediction of the basin is explored by using the long short-term memory (LSTM). The results show that LSTM can be successfully applied to flood risk prediction. The short-term prediction results of the model are good, and the area where the risk is seriously underestimated (the high and very high risk are identified as the very low risk) accounts for only 0.98% of the total basin on average. The prediction results can be used as a reference for watershed management organizations, so as to guide future flood disaster prevention.


Asunto(s)
Desastres , Inundaciones , Medición de Riesgo , Monitoreo del Ambiente , Humanos , Ríos
15.
BMC Public Health ; 20(1): 321, 2020 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-32223747

RESUMEN

BACKGROUND: Flooding is expected to increase due to climate change, population growth and urban development. The longer-term mental health impacts of flooding are not well understood. In 2015, the English National Study of Flooding and Health was established to improve understanding of the impact of flooding on health and inform future public health action. METHODS: We used 3 years of data from the English National Study of Flooding and Health. Participants who had consented to follow up were sent a questionnaire. Participants were classified into either "unaffected", "disrupted" or "flooded" according to their exposure. Logistic regression models were used to calculate adjusted odds ratios for probable depression, anxiety and post-traumatic stress disorder (PTSD) in each exposure group. The Wald test was used to assess the difference in probable mental health outcomes for those who did and did not experience "persistent damage" to their home. Conditional logistic regression was conducted to assess change in prevalence over the 3 years and to identify possible determinants of recovery. RESULTS: Eight hundred nineteen individuals were included in the final analysis - 119 were classified as unaffected, 421 disrupted and 279 flooded. Overall, 5.7% had probable depression, 8.1% had probable anxiety and 11.8% had probable PTSD, with higher prevalence in the flooded group compared with the unaffected group. After adjustment for potential confounders, probable mental health outcomes were higher in the flooded group compared to the unaffected group, significantly for probable depression (aOR 8.48, 95% CI 1.04-68.97) and PTSD (aOR 7.74, 95% CI 2.24-26.79). Seventy-seven (9.4%) participants reported experiencing persistent damage to their home, most commonly damp (n = 40) and visible mould (n = 26) in liveable rooms. Of the 569 participants who responded at all 3 years, a significant reduction in prevalence for all probable mental health outcomes was observed in the flooded group. CONCLUSIONS: Flooding can have severe long-lasting consequences on mental health in affected populations. If these problems are not identified and treated early, they may persist for years. Further research is necessary to develop and evaluate interventions to increase resilience in at risk populations and to ensure timely access to support services following flooding.


Asunto(s)
Ansiedad/epidemiología , Depresión/epidemiología , Desastres , Inundaciones , Trastornos por Estrés Postraumático/epidemiología , Adulto , Ansiedad/etiología , Estudios de Cohortes , Depresión/etiología , Inglaterra/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Modelos Logísticos , Masculino , Salud Mental , Persona de Mediana Edad , Morbilidad , Oportunidad Relativa , Prevalencia , Factores de Riesgo , Trastornos por Estrés Postraumático/etiología , Encuestas y Cuestionarios
16.
Environ Pollut ; 263(Pt B): 114415, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32229376

RESUMEN

In parts of developing countries, the over-exploitation of sands from inland waters has led to serious environmental concerns. However, understanding of the impacts of commercial sand dredging on inland water ecosystem functions remains limited. Herein, we assess the effects of this activity on the functional structure of the macroinvertebrate community and its recovery processes based on a 4-year survey, in the South Dongting Lake in China. Our result showed a simplified macroinvertebrate functional structures within the dredged area, as evidenced by a loss of certain trait categories (e.g., oval and conical body form) and a significant reduction in trait values due to the direct removal of macroinvertebrates and indirect alternations to physical environmental conditions (e.g., water depth and %Medium sand). Moreover, clear increases were observed in certain trait categories (e.g., small body size and swimmer) resulting from the dredging-related disturbance (e.g., increased turbidity) within the adjacent area. Furthermore, one year after the cessation of dredging, a marked recovery in the taxonomic and functional structure of macroinvertebrate assemblages was observed with most lost trait categories returning and an increase in the trait values of eight categories (e.g., body size 1.00-3.00 cm and oval body form) within the dredged and adjacent area. In addition, dispersal processes and sediment composition were the main driver for the structuring of the macroinvertebrate taxonomic and functional assemblages during the dredging stages, whilst water environmental conditions dominated the taxonomic structure and dispersal processes determined the functional structure during the recovery stage. Implications of our results for monitoring and management of this activity in inland waters are discussed.


Asunto(s)
Ecosistema , Lagos , China , Monitoreo del Ambiente , Inundaciones , Sedimentos Geológicos , Invertebrados , Arena
17.
Sci Total Environ ; 724: 138302, 2020 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-32247970

RESUMEN

Large water conservancy project can strongly alter the plant community composition, however, how these changes can potentially affect ecosystem carbon (C) and nitrogen (N) dynamics is not fully understood. Here, we investigated natural 13C and 15N abundance of C3 and C4 plants and soil in different fractions [labile C (LC) and N (LN), recalcitrant C (RC) and N (RN)]from 6 sites with two elevations (flooding zone, 145-175 m, area with revegetation due to flooding, N = 6); and unflooding zone, >175 m with original plant as a control, N = 3) in riparian zones of the Three Gorges Reservoir, China. The dominant species were the C4 plants in the upstream including Changshou (CS), Fuling (FL) and Zhongxian (ZX) and the C3 plants in the downstream in unflooding zone including Wanzhou (WZ) Badong (BD), and Zigui (ZG). C4 plant in flooding zone was significant decreased by mean 25% compared with unflooding zone in the upstream but significantly increased the by mean 59% in the downstream. The 13C isotopic differences between soil and plant (Δδ13C) was lower than zero in both flooding and unflooding in the upstream, but was only lower than zero in flooding zone in the downstream. The proportion of C3-derived C in soil organic carbon pool (average 74.64%) was lower for the flooding zone compared to the unflooding zone (average 87.26%) in most sites, while the proportion of C3-derived C in LC (average 44.38%) was decreased in the flooding zone compared to the unflooding zone (69.52%) in the downstream. Additionally, the δ15N values of soil were higher than plant community in most sites, and were strongly associated with soil C and N pool content, as well as soil pH. Overall, our results revealed that soil C accumulation was primarily determined by C3 plant in situ and new C input by existing dominant C4 plant, whereas soil N dynamics was predictably dependent on soil relative C and N availability in response to flooding at regional scale.


Asunto(s)
Ecosistema , Suelo , Carbono , China , Inundaciones
18.
Sci Total Environ ; 726: 138570, 2020 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-32305766

RESUMEN

The utilization of methanotrophs for reducing the global warming potential in a flooded paddy system is the progressive investigation in the recent. The field investigation was conducted in Tamil Nadu Rice Research Institute, Aduthurai. This study showed the effect of isolated methanotroph strain (MR15) on the reduction of methane emission and improvement in growth parameters and yield of paddy. The treatments included the diverse dosages of methanotroph consortium (0, 25, 50, 75 & 100%). The total seasonal methane emission varied between 1.96 and 5.04 kg ha-1 for the season of Kharif and 2.18 to 5.81 kg ha-1 for the season of Rabi owing to the footprint of methanotroph. Irrespective of treatments, the mean seasonal emission was more prominent during Rabi compared to the Kharif season. The dosage of methanotroph consortium significantly influenced not only seasonal methane emission but also the grain yield percentage, which increased over 100% Recommended Dose of Fertilizers (RDF). Application of 100% methanotroph consortium (i.e.6.25 kg ha-1) minimizes the methane emission by 60% with an increase in grain yield by 35% and lessens the usage of additional nutrients. Overall, this study showed a sign of atmospheric methane uptake with increase growth potential and yield of paddy cultivation using methanotroph consortium.


Asunto(s)
Oryza , Suelo , Agricultura , Fertilizantes , Inundaciones , India , Metano/análisis
19.
Environ Sci Pollut Res Int ; 27(18): 22829-22842, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32323240

RESUMEN

Water level (a vital indicator for flood warnings and water management in floodplains) has been changed notably due to climatic and anthropogenic forces; however, very little is known about the relative effects of these agents. In this study, we take the Taihu Plain as an example to investigate potential factors driving changes in water level components through quantiles from 1954 to 2014. To quantify the extent of water level component changes attributable to climate variability and human activity, several non-stationary models considering rainfall, tide, evaporation, and hydraulic regulation as covariates are established based on generalized additive models for location, scale, and shape. The results indicate that most water level components increased over time and changed abruptly around the mid-1980s. As for climatic factors, the variability of rainfall, tide and evaporation significantly affected water level variation based on most quantiles from 1954 to 2014. Among several kinds of human activities, hydraulic regulation was a key factor influencing water level based on a high correlation coefficient. Positive effects were identified from hydraulic regulation regarding the association between rainfall and water level components; these effects depend on water level quantiles and the amount of rainfall occurrence. Our study has broad implications, providing a better understanding of water level variation and regional flood management.


Asunto(s)
Inundaciones , Agua , Humanos , Modelos Estadísticos
20.
Sci Total Environ ; 727: 138469, 2020 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-32330710

RESUMEN

Managed environmental flows are one mechanism by which managers may restore carbon dynamics, diversity and ecological function of rivers affected by anthropogenic activities. Empirical studies that quantify such interactions in detail are few, so we measured the amounts of dissolved organic carbon, nutrients, algae and invertebrates in the main river channel following a managed environmental flow that inundated an adjacent floodplain forest. Dissolved organic carbon (DOC), seston carbon, total nitrogen (TN), and chlorophyll-a (chl-a) concentrations were greatly increased downstream. The net yield of DOC, seston carbon, TN and chl-a from the floodplain peaked at approximately 100, 50, 5 and 0.1 t d-1, respectively during the major flow event. Total phosphorus mobilisation peaked at approximately 0.4 t d-1. Stable isotope analysis showed that allochthonously-derived carbon was rapidly incorporated into biofilm and grazing macroinvertebrates, persisting in riverine food webs for up to four months following the flood. During a subsequent smaller flow event, the floodplain either generated no further carbon or nutrients, or was a sink for carbon and nutrients. Our results provide empirical support for the River Wave Concept and show that allowing floodplain water to return to the river downstream of forests is important for maintaining ecological function within the river channel.


Asunto(s)
Nitrógeno/análisis , Ríos , Animales , Carbono/análisis , Monitoreo del Ambiente , Inundaciones , Fósforo/análisis
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