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1.
Water Res ; 171: 115372, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31865130

RESUMO

It is well known that rainwater harvesting (RWH) can augment water supply and reduce stormwater pollutant discharges. Due to the lack of continuous 2D modelling of urban flood coverage and its associated damage, the ability of RWH to reduce urban flood risks has not been fully evaluated. Literature suggests that small distributed storage spaces using RWH tanks will reduce flood damage only during small to medium flooding events and therefore cumulative assessment of their benefits is needed. In this study we developed a new integrated modelling framework that implements a semi-continuous simulation approach to investigate flood prevention and water supply benefits of RWH tanks. The framework includes a continuous mass balance simulation model that considers antecedent rainfall conditions and water demand/usage of tanks and predicts the available storage prior to each storm event. To do so, this model couples a rainfall-runoff tank storage model with a detailed stochastic end-use water demand model. The available storage capacity of tanks is then used as a boundary condition for the novel rapid flood simulation model. This flood model was developed by coupling the U.S. EPA Storm Water Management Model (SWMM) to the Cellular-Automata Fast Flood Evaluation (CA-ffé) model to predict the inundation depth caused by surcharges over the capacity of the drainage network. The stage-depth damage curves method was used to calculate time series of flood damage, which are then directly used for flood risk and cost-benefit analysis. The model was tested through a case study in Melbourne, using a recorded rainfall time series of 85 years (after validating the flood model against 1D-2D MIKE-FLOOD). Results showed that extensive implementation of RWH tanks in the study area is economically feasible and can reduce expected annual damage in the catchment by up to approximately 30 percent. Availability of storage space and temporal distribution of rainfall within an event were important factors affecting tank performance for flood reduction.


Assuntos
Inundações , Chuva , Cidades , Água , Movimentos da Água , Abastecimento de Água
2.
J Environ Manage ; 253: 109753, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31677425

RESUMO

'Managed retreat' is gaining considerable attention as part of megacities' climate change adaptation and resilience enhancement toolkits, and as a policy option for disaster risk reduction in coastal regions. The overarching objective of managed retreat is to reduce the exposure of people and assets to flooding, storm surges and sea level rise by retreating from these threats in a planned fashion. Managed retreat is one of four main options covered in the 'PARA' (protect/accommodate/retreat/avoid) framework explained in this paper, which can be used to enhance resilience in coastal megacities. In this paper, qualitative research methods were used to collect primary data on the feasibility of using managed retreat for two case study coastal megacities: Manila, Philippines, and Vancouver, Canada. Both case studies review the risk context of each city, local climate change adaptation/disaster risk reduction (CCA/DRR) policies linked to managed retreat, examples of managed retreat practice, and barriers to managed retreat identified through primary or secondary data analysis. Comparisons between the two cases are then carried out, and similarities and differences are highlighted. The paper concludes by suggesting possible means by which barriers to managed retreat might be overcome.


Assuntos
Mudança Climática , Inundações , Canadá , Cidades , Filipinas
3.
Environ Monit Assess ; 192(1): 30, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31823074

RESUMO

The Gabcíkovo Water Project, a major construction of damming and canalizing on the upper part of the middle Danube, significantly changed hydrological regime of the Danube inland delta, destroyed or affected most of the 230 km2 of wetlands and directly disrupted the original and unique ecosystem along a 37 km long river stretch. The aim of this study was to describe the effect of the Gabcíkovo Waterworks on the taxonomical and functional structure of the molluscan assemblages in the Danube riparian floodplain forests. The results demonstrate that the Gabcíkovo Waterworks had a direct and long-lasting effect on the direction of the succession of terrestrial molluscan assemblages, especially in the area of the by-pass section. The changes in the soil moisture caused by the waterworks' operation led to significant changes in the species and functional composition of these assemblages. More specifically, however, the proportion of the generalists which prefer dry biotopes increased, while the number of moisture-demanding species decreased. Our results indicate that the current artificial flooding system cannot fully replace previous natural floods in the Danube inland delta, and it is also insufficient for restoration and preservation of the humidity conditions in the softwood floodplain forests which would be similar to the pre-operation period of the Gabcíkovo Waterworks.


Assuntos
Monitoramento Ambiental/métodos , Hidrologia/estatística & dados numéricos , Rios , Caramujos/fisiologia , Áreas Alagadas , Animais , Inundações/estatística & dados numéricos , Dinâmica Populacional , Solo/química
4.
Environ Monit Assess ; 192(1): 48, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31844992

RESUMO

The devastations and damages caused by climate change are apparent across the globe, specifically in the South Asian region where vulnerabilities to climate change among residents are high and climate change adaptation and mitigation awareness are extremely low. Pakistan's low adaptive capacity due to high poverty rate, limited financial resources and shortage of physical resources, and continual extreme climatic events including varying temperature, continual flooding, melting glaciers, saturation of lakes, earthquakes, hurricanes, storms, avalanches, droughts, scarcity of water, pest diseases, human healthcare issues, and seasonal and lifestyle changes have persistently threatened the ecosystem, biodiversity, human communities, animal habitations, forests, lands, and oceans with a potential to cause further damages in the future. The likely effect of climate change on common residents of Pakistan with comparison to the world and their per capita impact of climate change are terribly high with local animal species such as lions, vultures, dolphins, and tortoise facing extinction regardless of generating and contributing diminutively to global GHG emissions. The findings of the review suggested that GHG emissions cause climate change which has impacted agriculture livestock and forestry, weather trends and patterns, food water and energy security, and society of Pakistan. This review is a sectorial evaluation of climate change mitigation and adaption approaches in Pakistan in the aforementioned sectors and its economic costs which were identified to be between 7 to 14 billion USD per annum. The research suggested that governmental interference is essential for sustainable development of the country through strict accountability of resources and regulation implemented in the past for generating state-of-the-art climate policy.


Assuntos
Mudança Climática , Monitoramento Ambiental , Agricultura/tendências , Animais , Ecossistema , Inundações , Agricultura Florestal , Florestas , Humanos , Gado , Paquistão
5.
Huan Jing Ke Xue ; 40(11): 4944-4952, 2019 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854560

RESUMO

The construction of the Three Gorges Reservoir has had certain effects on the ecological environment of the water and serious phytoplankton blooms have occurred in its tributary embayment. To explore the spatial distribution of nitrogen and phosphorus nutrients and chlorophyll-a in different tributaries of the Three Gorges Reservoir, a water quality study (June 2018) was conducted in the Xiangxi River, Shengnongxi River, and Daning River of the Three Gorges Reservoir. The results showed that the average TN in the three tributaries was 1.86 mg·L-1, 1.90 mg·L-1, and 1.43 mg·L-1, respectively, and average TP was 0.09 mg·L-1, 0.07 mg·L-1, and 0.05 mg·L-1, respectively. Single-factor ANOVA analysis showed that the spatial difference in TN was significant and occurred in the following order:Shennongxi River > Xiangxi River > Daning River. There were significant differences in the spatial distribution of TP, which were in the order off Xiangxi River > Shennongxi River > Daning River. The mean concentrations of chlorophyll-a in the three tributaries was 6.41 µg·L-1, 21.39 µg·L-1, and 9.85µg·L-1, respectively. The results from the Pearson correlation analysis, showed that chlorophyll-a concentrations were closely related to TP distribution in all tributaries, but Zeu/Zmix was also correlated with the distribution of chlorophyll-a in the Shennongxi River and Daning River. The ratio of TN and TP concentrations was 22.36, 26.76, and 28.6, respectively, which revealed that TP is a critical and limiting factor affecting phytoplankton growth in its tributary embayment.


Assuntos
Clorofila A , Rios , Sais , China , Clorofila , Monitoramento Ambiental , Eutrofização , Inundações , Nitrogênio , Nutrientes , Fósforo , Estações do Ano
6.
Huan Jing Ke Xue ; 40(9): 4287-4294, 2019 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854896

RESUMO

In order to evaluate the effects and mechanisms of flooding measures, soil conditioner, silicon mineral fertilizer and sprayed foliar fertilizer, gypsum powder, and their multiple treatments for reducing Cd accumulation in rice grown in Cd-contaminated soil. A plot experiment was conducted in three different Cd-contaminated soils. The results showed that flooding measures, a single application of conditioning agents, and combined application and flooding treatment can reduce soil-available Cd and the Cd content in various organs of rice with 6.58%-30.01% reduction in soil available-Cd and 12.64%-68.68% reduction in Cd content in brown rice, respectively. The Cd reduction decreased in the following order:comprehensive treatment (T6) > basic application of gypsum powder (T5) > base Xiangrunbang state soil conditioner (T3) > mineral silicon fertilizer and spray foliar fertilizer (T4) > flood treatment (T2). In addition, the average value of the reduction effect of the Cd content in brown rice was calculated. The five treatments in the experiment reduced the enrichment of various parts of the rice, which is a main reason for the decrease in Cd content in the brown rice. According to the field plot test, the combined application of the basic conditioning agent, mineral silicon fertilizer, and sprayed foliar fertilizer, and gypsum powder and flooding measures can be used as an effective method for Cd pollution control in Cd-contaminated cultivated rice.


Assuntos
Cádmio , Oryza , Poluentes do Solo , Fertilizantes , Inundações , Oryza/química , Solo
7.
Sci Total Environ ; 694: 133651, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31756797

RESUMO

Leptospirosis is considered the most globally widespread zoonotic illness; it has been classified as an emerging or reemerging infectious disease by the World Health Organization. Leptospirosis is a disease caused by a pathogenic spirochete of the genus Leptospira. The infection occurs by contacting with the urine of animal reservoirs or contaminated environments. Leptospirosis can be controlled by vaccines used mainly in animals, antibiotics given to exposed humans, and flood-affected people moved to a safe place. Northeastern Argentina accounts for the highest annual number of cases and deaths due to leptospirosis of the country. This interdisciplinary study aims to analyze the spatial and temporal distribution of leptospirosis, and assesses the hydroclimatic factors that give rise to the outbreaks in northeastern Argentina. The main goal is to detect the hydroclimatic indicators that can influence leptospirosis outbreaks occurrence in the northeastern Argentina. We perform a spatio-temporal analysis of the leptospirosis in the provinces of Santa Fe and Entre Ríos to distinguish the regions, years and seasons with the highest incidence of this disease. This study analyzes confirmed cases of leptospirosis between 2009 and 2018 years. Hydroclimatic indicators (monthly total precipitation, monthly river hydrometric level and Oceanic Niño Index) associated with outbreaks of leptospirosis vary in different spatial scales (provincial, departmental and cities). In the last outbreak of leptospirosis in 2015-2016 the number of cases was lower than expected. This could have been a consequence of increased prophylaxis in that flood event. Therefore, this is a variable that should be incorporated in future studies.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Inundações/estatística & dados numéricos , Leptospirose/epidemiologia , Argentina/epidemiologia , Clima , Surtos de Doenças , Humanos , Incidência , Análise Espaço-Temporal
8.
J Environ Manage ; 250: 109363, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31703242

RESUMO

The past two decades have witnessed growing global concern about excessive greenhouse gas (GHG) emissions by reservoirs and the development of hydropower. Literature review showed that life cycle GHG emissions per energy production of collected global dataset ranged from 0.04 to 237.0 gCO2eq/kW⋅h, with a mean of 25.8 ±â€¯3.0 gCO2eq/kW⋅h. Synthesis from the China's five largest hydro-projects and other publications estimated that the large- and mid-scale hydro-projects in China had a carbon footprint between 6.2 gCO2eq/kWh and 34.6 gCO2eq/kWh, with a mean value of 19.2 ±â€¯6.8 gCO2eq/kWh (mean ±â€¯sd.). Over 80% of the carbon footprint of the hydro-projects could be conservatively allocated to hydroelectricity generation, while the rest could then be allocated to flood control services. In the Three Gorges Dam Project, the allocated life cycle GHG emissions per energy production of its hydroelectricity production was estimated to be 17.8 gCO2eq/kW⋅h. GHG emissions from reservoir sediments and in the phase of operation and maintenance were still uncertain. There is still a need of in-depth research on reservoir carbon cycling to quantify net reservoir GHG emissions.


Assuntos
Pegada de Carbono , Gases de Efeito Estufa , China , Inundações , Efeito Estufa
9.
Environ Monit Assess ; 191(12): 752, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31732799

RESUMO

Tropical regions are characterized by hydrological extreme events, which are likely to be exacerbated by climate change. Therefore, quantifying the extent to which climate change may damage a hydrological system becomes crucial. This paper aims to evaluate the findings from previous research on projected impacts of climate change on hydrological systems located in regions bounded by the Tropic of Cancer and the Tropic of Capricorn. It intends to provide an in-depth understanding of the climatic conditions, applied approaches, climate change impacts on future streamflow, and measures to reduce prediction uncertainty in the tropics. The review revealed that there is a significant variation in the magnitude of climate change impacts on streamflow in the tropics. The reason for the inconsistent trend prediction is that projections are heavily dependent on the trajectory of greenhouse gas emissions, climate model structural differences, and uncertainty of downscaling methods and hydrological models. Therefore, to minimize the uncertainty and maximize confidence in streamflow projections, it is essential to apply multi-member model ensembles and to clarify the adaptation strategy (coping, adjusting, or transforming).


Assuntos
Mudança Climática/estatística & dados numéricos , Monitoramento Ambiental , Hidrologia , Rios , Secas , Inundações , Modelos Teóricos , Chuva
10.
Environ Monit Assess ; 191(12): 758, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31741070

RESUMO

The unsuitable construction of unpaved roads has been causing problems related to the formation of erosive processes, sediments in watersheds, bogs, flooding, and holes. Presuming that the areas where flow accumulation intersects unpaved roads represent risk points, our objectives are (1) to develop a qualitative method based on the GIS software management tool (FlowAccRoad) for the identification of the intersection points between flow accumulation and roads and (2) to verify the discrepancy between the points of intersection produced by digital elevation models (DEM) accounting for different spatial resolutions. In the GIS environment, we used the Shuttle Radar Topography Mission (SRTM) and Goiania (GOI) digital elevation models for the modeling of flow accumulation and vectorization of the unpaved roads, both of which are based on the Bandeira Stream Watershed in Goiania, Goiás, Brazil. This highlights that 54 points of intersection between the flow accumulation and unpaved roads present problems related to erosive processes and quagmires, among others. The FlowAccRoad method identified the principal critical points observed in the field, using both the DEM of 30.4 m of spatial resolution (SRTM) and also of 4.8 m of spatial resolution (GOI). From the FlowAccRoad method, we observed that 91% of the risk points identified through the GOI DEM were located less than 20 m from valid points in the field by using GPS. Analyzing the SRTM DEM, only 45% of the critical risk points identified by the method were located less than 20 m from valid points in the field.


Assuntos
Monitoramento Ambiental/métodos , Fenômenos Geológicos , Brasil , Inundações , Radar , Rios , Áreas Alagadas
11.
Environ Monit Assess ; 191(12): 760, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31745827

RESUMO

Remote sensing-based flood inundation mapping and monitoring is very crucial input before, during, and after floods. Ganga-Ramganga doab is one of the prolonged flood-affected area in middle Ganga plain due to seasonal monsoon which leads to rise in water levels of Ganga and Ramganga rivers. The focus of the present study is to map severe flood condition captured through synthetic aperture radar (SAR) data during August-September 2018, and to explain the impact on Ramganga river morphology. SAR data is preferred for flood mapping and real-time monitoring in all weather conditions. In this study, dual-polarized (VV and VH) Sentinel-1 SAR images coupled with hydrological data (river water level) were used to produce flood inundation maps. Thresholding technique has been applied to determine the flood mapping through Sentinel-1 data. VH and VV polarisation methods have been applied for a comparison of their respective accuracies in delineating surface water. Results have been validated against a Sentinel-2 optical image, and both polarisations produced a total accuracy of more than 93%. VV polarisation has high accuracies than VH polarisation as similar results are observed in previous studies as well. The finding reveals that severe bank erosion took place in the Ramganga channel which significantly affected the channel morphology, mainly the massive mobilisation of channel sediments. The results show that the average channel width increased from 46 to 336 m. The proposed approach demonstrates that the microwave remote sensing data along with GIS can be used efficiently for flood inundation mapping, monitoring, and analysing its effect on channel morphology. Therefore, the results of this study will help to take the initiative to reduce the flood hazard impact in the doab area and increase the flexibility in the process of flood management.


Assuntos
Monitoramento Ambiental/métodos , Inundações , Rios , Bangladesh , Água Doce , Hidrologia , Radar , Tempo (Meteorologia)
12.
Am Surg ; 85(10): 1094-1098, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31657301

RESUMO

On January 9, 2018, a catastrophic debris flow devastated Montecito, California. A 30-foot wall of boulders, mud, and debris ran down the hillsides at 15 miles per hour injuring dozens and causing 21 prehospital deaths. A retrospective review was conducted of the victims from the debris flow presenting to Cottage Health. Injury patterns, procedures performed, complications, length of stay, and outcomes were analyzed. Twenty-four patients were evaluated; 15 were admitted. Of the patients admitted, the most common presenting symptoms were soft tissue injuries (100%), hypothermia (67%), craniofacial injuries (67%), corneal abrasions (53%), and orthopedic injuries (47%), as well as loss of an immediate family member during the incident (73%). Procedures included skin irrigation (93%), operative soft tissue debridement (47%), body orifice irrigation due to mud impaction (40%), and orthopedic repair of fractures and ligaments (40%). All survived to discharge. "Debris flow syndrome" can be defined as a pattern of injuries, including soft tissue injuries, hypothermia, craniofacial trauma, corneal abrasions, orthopedic injuries, and mud impaction. Managing the debris flow syndrome requires co-ordinated and specialized care.


Assuntos
Osso e Ossos/lesões , Lesões da Córnea/epidemiologia , Desastres/estatística & dados numéricos , Traumatismos Faciais/epidemiologia , Inundações/estatística & dados numéricos , Hipotermia/epidemiologia , Deslizamentos de Terra/estatística & dados numéricos , Lesões dos Tecidos Moles/epidemiologia , Adolescente , Adulto , Idoso , California/epidemiologia , Criança , Pré-Escolar , Lesões da Córnea/etiologia , Lesões da Córnea/cirurgia , Traumatismos Faciais/etiologia , Traumatismos Faciais/cirurgia , Feminino , Humanos , Hipotermia/etiologia , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Lesões dos Tecidos Moles/etiologia , Lesões dos Tecidos Moles/cirurgia , Procedimentos Cirúrgicos Operatórios/estatística & dados numéricos , Síndrome , Adulto Jovem
13.
J Environ Manage ; 252: 109672, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31629176

RESUMO

Understanding household's decision making in agricultural production to natural hazards is significant for policymakers and extension organizations in supporting farmers to optimize adaptive strategies, there are, however, still limited empirical researches that emphasize the determinants affecting the choice of measures in the process of adaptation. This paper explores the decision-making process of rural households in adapting to flash floods and landslides (FF&LS) by conducting a household survey on 405 purposively selected households in Yen Bai province, one of the poorest mountainous regions in Vietnam. Based on the multi-portfolio framework, the study assumes that farmers have multiple choice of adaptation strategies simultaneously and these adaptation measures are correlative. Multivariate Probit models were used to figure out the household decision making process in adapting to FF&LS. Survey results showed that changing cropping patterns, crop variegation, diversifying types of crop varieties, as well as managing and implementing crop protection (soil and plant) are the primary adaptation measures applied by local farmers. Furthermore, lack of money, inadequate support from local government, shortage of machinery and technical equipment, as well as insufficient knowledge about FF&LS were listed as major constraints in the study area. The MVP analysis indicated that all farmers' perception, socio-economic, farming features, and institutional conditions strongly influence the farmers' adaptation decisions regarding FF&LS. Future policies may therefore need to consider these major contributing factors with appropriate interventions to facilitate suitable adaptations for local farmers.


Assuntos
Fazendeiros , Deslizamentos de Terra , Agricultura , Tomada de Decisões , Inundações , Humanos , Vietnã
14.
Environ Monit Assess ; 191(11): 656, 2019 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-31630270

RESUMO

The negative consequences of urbanisation have been recently recognised despite the social and economic benefits it provides to the community. Effects of urbanisation include increases in surface runoff, frequency and magnitude of floods and urban water harvesting capacity. Accordingly, this study utilised multi-spectral and multi-resolution satellite images combined with field data to conduct a quantitative assessment of the impact of urbanisation on urban flooding for the period of 1975-2015 in Ajman City, United Arab Emirates (UAE). Results showed that urban areas in the city have increased by approximately 12-fold over the period 1975-2015, whilst the population increased by approximately 16-fold. Owing to a substantial increase in urbanisation (as impervious areas expanded), minimum precipitation to generate runoff in built areas dropped from approximately 16.37 mm in 1975 to approximately 13.3 mm in 2015, which caused a substantial increase in the surface runoff. To visualise the flooding potential, urban flooding maps were generated using a well-established decision analysis technique called Analytical Hierarchy Process. The latter adopted three thematic factors, namely excess rain, elevation and slope. Flooding potential was then found to have increased substantially, specifically in the downtown area. Finally, this study is expected to contribute highly to flood protection and sustainable urban storm water management in Ajman City.


Assuntos
Monitoramento Ambiental/métodos , Inundações , Chuva , Urbanização , Movimentos da Água , Cidades , Modelos Teóricos , Imagens de Satélites , Análise Espaço-Temporal , Emirados Árabes Unidos
15.
Water Sci Technol ; 80(3): 478-486, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31596259

RESUMO

This paper presents a method of quantifying the uncertainty associated with inundation damage data for an urban catchment when undertaking stormwater drainage design and management. Usually flood damage is estimated by multiplying the inundated asset value by the damage rate corresponding to the inundation depth. The uncertainty of the asset value and the damage rate is described by probability distributions estimated from an analysis of actual flood damage data from a national government survey. With the inclusion of uncertainty in the damage rate and asset value, the damage potential curve defining the damage-frequency relationship is no longer a deterministic single-value curve. Through Monte Carlo simulations, which incorporate the uncertainty of the inundation damage from the damage rate and asset value, a probabilistic damage potential relation can be established, which can be expressed in terms of a series of curves with different percentile levels. The method is demonstrated through the establishment of probabilistic damage potential curves for a typical urban catchment, the Zenpukuji river basin in Tokyo Metropolis, under two scenarios, namely, with and without a planned flood control reservoir.


Assuntos
Inundações , Gestão de Riscos , Probabilidade , Tóquio , Incerteza
17.
Environ Manage ; 64(5): 608-625, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31570966

RESUMO

If the aim of flood risk management (FRM) is to increase society's resilience to floods, then a holistic treatment of flood risk is required that addresses flood prevention, defence, mitigation, preparation, and response and recovery. Progressing resilience-based management to flood risk requires both diversity and coordination of policy across multiple jurisdictions. Decision makers and the types of FRM policy decisions they make play a key role in implementing FRM policies and strategies that progress flood resilience. This paper explores how policy preferences held by FRM decision makers relate to the characteristics of resilient FRM policy. The research was conducted in three flood-prone provinces in western Canada using a multi-criteria analytical approach. The results show that while decision maker FRM priorities are similar across the Canadian Prairies, their preferred FRM policies differ. Further, preferred FRM policies were largely resistance-based and influenced at least as much by flood experiences and perceptions of flood risk as by more obvious administrative pressures such as cost, public acceptability, and environmental protection. Several observations emerge from these results for advancing a coordinated, diversified approach to FRM which is required for resilience, both for western Canada and for FRM more broadly.


Assuntos
Inundações , Pradaria , Canadá , Tomada de Decisões , Gestão de Riscos
18.
Environ Entomol ; 48(6): 1340-1348, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31568549

RESUMO

Riparian zones are interesting habitats as they are important transitional zones between terrestrial and aquatic ecosystems, but highly threatened by human disturbances. They support a high arthropod diversity as they experience periodic flooding disturbance and sharp environmental gradients. Their associated arthropod fauna are of high conservation value. Nevertheless, their arthropod diversity remains largely unknown, and its distribution pattern along elevational gradients is poorly understood. Few data are available on the effects of flood regimes and other factors in determining riparian arthropod communities. In this study, we investigated the diversity and distribution of riparian arthropods along an elevational gradient and determined the major factors structuring the arthropod communities in the drawdown zone of the Three Gorges Reservoir, China. Significant compositional and structural changes of riparian arthropod communities were observed along the test elevational gradient. The abundance and richness of riparian arthropods increased with elevation. The relative abundance of predators decreased with elevation, whereas the saprovores and omnivores showed an upward trend along the elevational gradient. Redundancy analysis showed that there were significant interactions between the flood regimes, plant communities, and soil conditions. Among these environmental factors studied, flood duration was the main factor in structuring the riparian arthropod communities. Conservation and restoration strategies should consider flood duration in the operation of large reservoirs because riparian arthropods are particularly sensitive to flood regimes.


Assuntos
Artrópodes , Animais , China , Ecossistema , Inundações , Solo
19.
Environ Pollut ; 255(Pt 1): 113249, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31542664

RESUMO

Efficient removal of labile arsenic (As) from paddy soil is a fundamental pathway mitigating As accumulation in rice from a long-term perspective. In this study, a porous and pencil-shaped column prepacked with quartz-supported nanoscale zero-valent iron (NZVI) was designed to extract elevated porewater As from paddy soil under flooded condition. With fine quartz as supporting medium in the core layer, only 0.07% out-migration of the loaded NZVI occurred in arsenite As(III) solution. At pH 5-9, removal of aqueous As(III) with NZVI-column was 73-78%, while silicic acid and phosphate at their environmentally realistic concentrations exhibited 27-30% and 14-17% inhibition on As(III) extraction, respectively. For two paddy soils with slight (S-As) and moderate (M-As) As contamination, four cycles of intermittent extraction with NZVI-column induced steady and marked decrease in porewater As. By the end of four successive extractions, profiles of DGT-labile As in S-As and M-As soils decreased by 22% and 29% on average with simultaneous decline of the most available fraction of soil As (including soluble and exchangeable fraction) by 26% and 17%, respectively. For the post-extracted two soils, As accumulation of rice seedlings declined by 29-57% than those in control. These results identify the effectiveness of NZVI-column in extracting elevated labile As from paddy soils with the aid of flooding. Targeting fast removal of high porewater As, column-extraction could serve as the first step in "remediation train" of paddy soils with relatively high As to shorten cleanup time by rendering much lowered soil As burden for the following phytoextraction and other measures.


Assuntos
Arsênico/análise , Recuperação e Remediação Ambiental/métodos , Poluentes do Solo/análise , Arsenitos , Inundações , Ferro/análise , Oryza/metabolismo , Quartzo , Solo/química
20.
J Environ Manage ; 251: 109553, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31539701

RESUMO

In recent decades, urban developments along rivers have experienced high flooding risks, elevated by increasing urbanization. Due to the expansion of urban areas, flood mitigation strategies must rely on nonstructural flood management policies. This study evaluated the impacts of pluvial floods considering fluvial flooding effects through field surveys and numerical model simulations. Nonstructural flood protection measures are provided by establishing warning water levels based on variant scenario simulations. The results reveal that the aggravated drainage system overflow induced by elevated river water is significant when considering river flooding effects. As a result, current drainage systems have failed to meet the designed flood protection standards, indicating the need to produce potential inundation maps and to establish warning water levels. To prevent the main evacuation route of each settlement from being blocked due to flooding, the proposed warning water levels support timely and effective evacuations. Public community centers and schools in noninundation areas near settlements were identified as possible shelters based on the proposed warning water levels and inundation maps. We conclude that although the riverside areas without dike protection could sustain natural environments and landscapes, they must incorporate nonstructural flood protection measures. At the same time, it must be considered that river flood levels may reduce urban drainage capacity.


Assuntos
Inundações , Rios , Urbanização
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