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1.
Sensors (Basel) ; 21(17)2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34502767

RESUMO

Recent years have witnessed a growing interest in techniques and systems for rainfall surveillance on regional scale, with increasingly stringent requirements in terms of the following: (i) accuracy of rainfall rate measurements, (ii) adequate density of sensors over the territory, (iii) space-time continuity and completeness of data and (iv) capability to elaborate rainfall maps in near real time. The devices deployed to monitor the precipitation fields are traditionally networks of rain gauges distributed throughout the territory, along with weather radars and satellite remote sensors operating in the optical or infrared band, none of which, however, are suitable for full compliance to all of the requirements cited above. More recently, a different approach to rain rate estimation techniques has been proposed and investigated, based on the measurement of the attenuation induced by rain on signals of pre-existing radio networks either in terrestrial links, e.g., the backhaul connections in cellular networks, or in satellite-to-earth links and, among the latter, notably those between geostationary broadcast satellites and domestic subscriber terminals in the Ku and Ka bands. Knowledge of the above rain-induced attenuation permits the retrieval of the corresponding rain intensity provided that a number of meteorological and geometric parameters are known and ultimately permits estimating the rain rate locally at the receiver site. In this survey paper, we specifically focus on such a type of "opportunistic" systems for rain field monitoring, which appear very promising in view of the wide diffusion over the territory of low-cost domestic terminals for the reception of satellite signals, prospectively allowing for a considerable geographical capillarity in the distribution of sensors, at least in more densely populated areas. The purpose of the paper is to present a broad albeit synthetic overview of the numerous issues inherent in the above rain monitoring approach, along with a number of solutions and algorithms proposed in the literature in recent years, and ultimately to provide an exhaustive account of the current state of the art. Initially, the main relevant aspects of the satellite link are reviewed, including those related to satellite dynamics, frequency bands, signal formats, propagation channel and radio link geometry, all of which have a role in rainfall rate estimation algorithms. We discuss the impact of all these factors on rain estimation accuracy while also highlighting the substantial differences inherent in this approach in comparison with traditional rain monitoring techniques. We also review the basic formulas relating rain rate intensity to a variation of the received signal level or of the signal-to-noise ratio. Furthermore, we present a comprehensive literature survey of the main research issues for the aforementioned scenario and provide a brief outline of the algorithms proposed for their solution, highlighting their points of strength and weakness. The paper includes an extensive list of bibliographic references from which the material presented herein was taken.


Assuntos
Algoritmos , Chuva
3.
Water Res ; 202: 117457, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34358909

RESUMO

Microplastic particles in stormwater pose significant threats to the environment. This study investigated how effective a stormwater treatment train was at removing rubber, bitumen and other microplastics (incl. fibers, fragments, and paint particles) in the 100-300 µm and >300 µm size fractions from highway runoff. The two treatment trains comprise a gross pollutant trap (GPT) followed by either a vegetated bioretention cell or non-vegetated sand filter. Flow-proportional composite samples were taken from the highway runoff, GPT outflow and the outflow from the two parallel filters during nine rain events to determine overall treatment performance, as well as the performance of individual system components. The identified rubber, bitumen and other microplastic particles mainly represented the 100-300 µm fraction and included high ratios of rubber (30%) and bitumen (60%). Overall, the treatment train efficiently removed rubber, bitumen and other microplastic particles in the 100-300 µm size fraction from the stormwater. The filter cells accounted for a major share of this removal, as the GPT did not reduce microplastic particle concentrations. This observation is likely explained by the fact that the rubber, bitumen and other microplastic particles have a density close to the density of water and thus removal by sedimentation is decreased. This identified an inherent weakness of the system; more specifically, the high microplastic concentrations in the surface water of the GPT means there can be a risk of microplastic release through overflow pits when inflows surpass the system capacity. Despite some differences, both the vegetated bioretention cell and the non-vegetated sand filter removed rubber, bitumen and other microplastic particles to similar extent.


Assuntos
Poluentes Ambientais , Purificação da Água , Hidrocarbonetos , Microplásticos , Plásticos , Chuva , Borracha , Abastecimento de Água
4.
Artigo em Inglês | MEDLINE | ID: mdl-34444560

RESUMO

Surface runoff determination in urban areas is crucial to facilitate ex ante water planning, especially in the context of climate and land cover changes, which are increasing the frequency of floods, due to a combination of violent storms and increased imperviousness. To this end, the spatial identification of urban areas prone to runoff accumulation is essential, to guarantee effective water management in the future. Under these premises, this work sought to produce a tool for automated determination of urban surface runoff using a geographic information systems (GIS). This tool, which was designed as an ArcGIS add-in called ArcDrain, consists of the discretization of urban areas into subcatchments and the subsequent application of the rational method for runoff depth estimation. The formulation of this method directly depends on land cover type and soil permeability, thereby enabling the identification of areas with a low infiltration capacity. ArcDrain was tested using the city of Santander (northern Spain) as a case study. The results achieved demonstrated the accuracy of the tool for detecting high runoff rates and how the inclusion of mitigation measures in the form of sustainable drainage systems (SuDS) and green infrastructure (GI) can help reduce flood hazards in critical zones.


Assuntos
Sistemas de Informação Geográfica , Movimentos da Água , Cidades , Inundações , Chuva , Solo
5.
Molecules ; 26(16)2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34443694

RESUMO

Thymus vulgaris L. is one of the most commonly used medicinal and aromatic plants (MAPs), owing to a range of therapeutic properties of its essential oil. Plant growth, biomass yield, essential oil content and composition are influenced by chemotype, environmental conditions, cultivation techniques and vegetative development. Since in MAPs cultivation special attention is paid on high quality of raw material, the adoption of sustainable agriculture methods is of pivotal importance. Therefore, we evaluated the agronomic and qualitative performances of two Thymus vulgaris L. chemotypes, organically cultivated under the Mediterranean climate of hilly lands of central Italy for three consecutive years (2017-2019). Along the trial, total above-ground dry biomass significantly increased from the 1st to 3rd year after planting and large variations in the main biological, biometric and productive traits were observed between the two chemotypes. The 'thymol' chemotype EO obviously showed thymol as the major constituent (51.26-49.87%) followed by γ-terpinene and p-cymene. The 'linalool' chemotype EO showed high percentages of oxygenated monoterpenes (about 90%) with linalool (75%), linalyl acetate (8.15%) and b-caryophyllene (3.2%) as main constituents. This study highlighted that T. vulgaris can be successfully organically grown in the hilly lands of Tuscany, with interesting biomass and essential oil yields, even though the plants were in the initial years of crop establishment (start in 2017). The introduction of this species into organic cultivation systems could contribute to obtain high-quality raw material, as well as to enhance crop rotation diversification, which is of pivotal importance in the management of organic farms.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Óleos Voláteis/análise , Thymus (Planta)/química , Destilação , Itália , Análise de Componente Principal , Chuva , Estações do Ano , Solo/química
6.
BMC Res Notes ; 14(1): 319, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34419141

RESUMO

OBJECTIVE: Reported rainfall data from multiple rain gauges and its corresponding estimate from Dual-Polarization (Dual-Pol) radar is presented here. The ordered set of data pairs were collected from multiple peer reviewed publications spanning across the last decade. DATA DESCRIPTION: Taken from multiple sources, the data set represents several radar sites and rain gauge sites combined for 12,734 data points. The data is relevant in various applications of hydrometeorology and engineering as well as weather forecasting. Further, the importance of accuracy in radar precipitation estimates continues to increase, necessitating the incorporation of as much data as possible.


Assuntos
Radar , Chuva , Previsões
8.
Environ Monit Assess ; 193(9): 607, 2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34455498

RESUMO

Soil nutrients are the key factors in soil fertility, which have important roles in plant growth. Determining soil nutrient contents, including macro and micronutrients, is of crucial importance in agricultural productions. Conventional laboratory techniques for determining soil nutrients are expensive and time-consuming. This research was aimed to develop linear regression (LR) models for remote sensing of total nitrogen (TN) (mg/kg), available phosphorous (AP) (mg/kg), available potassium (AK) (mg/kg), and micronutrients such as iron (Fe) (mg/kg), manganese (Mn) (mg/kg), zinc (Zn) (mg/kg), and copper (Cu) (mg/kg) extracted by DTPA in rain-fed agricultural lands in the northwest of Iran. First, 101 soil samples were collected from 0-30 cm of these lands and analyzed for selected nutrient contents. Then a linear regression along with principal component analysis was conducted to correlate soil nutrient contents with reflectance data of different Landsat OLI bands. Finally, the spatial distributions of soil nutrients were drawn. The results showed that there were linear relationships between soil nutrient contents and standardized PC1 (ZPC1). The highest significant determination coefficient with an R2 value of 0.46 and the least relative error (%) value of 11.97% were observed between TN and ZPC1. The accuracy of the other LR's developed among other soil nutrient contents and remotely sensed data was relatively lower than that obtained for TN. According to the results obtained from this study, although remote sensing techniques may quickly assess soil nutrients, new techniques, technologies, and models may be needed to have a more accurate prediction of soil nutrients.


Assuntos
Monitoramento Ambiental , Solo , Irã (Geográfico) , Nutrientes , Chuva
9.
J Environ Manage ; 297: 113375, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34325375

RESUMO

This study evaluates the operational status of twenty-six biofilter facilities across nine cities in Sweden, with respect to their functional design criteria, engineered design features (filter media composition, hydraulic conductivity, and drawdown time), and includes a visual inspection of the biofilter components (pre-treatment, in/outlet structures, filter media, and vegetation). These indicators were used to examine the performance level of each biofilter in achieving their design objectives set by the operators. Furthermore, it was investigated whether the biofilter facilities had been properly maintained to meet the objectives. Results indicate that the soil media used was consistent with respect to percentage sand, fines, and organic matter and comparable to design recommendations used by municipalities in other countries. The field-tested hydraulic conductivity for the biofilters ranged from 30 to 962 mm/h. This range of values, along with noticeable sediment accumulation within the biofilter indicate that not all the sites were operating optimally. Pre-treatment stages in poor condition with high volumes of sediment and litter accumulation were the primary causes for, and indicators of, low hydraulic conductivity rates. The ponding volume calculations revealed that at least 40 % of facilities did not have enough capacity to retain every-day and/or design rainfall due to design and/or construction flaws. These analyses raise concerns that, for a considerable number of the biofilters surveyed, water retention and flood protection identified by operators as prioritised objectives are not being met. This raises significant concerns about the functionality of biofilter in practice. Finally, some suggestions are given for tackling the design and maintenance problems discovered.


Assuntos
Filtração , Purificação da Água , Cidades , Chuva , Solo , Suécia
10.
J Environ Manage ; 296: 113187, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34217940

RESUMO

On the cultivated slopes of the highlands of southwest Ethiopia, soil degradation due to water erosion is a challenge for crop production. To limit surface runoff and soil erosion, soil bunds often in combination with trenches, constructed along contour lines, are common. In addition to the interception of surface runoff, soil bunds may affect crop yield. Here, we evaluate effect of soil bunds on surface runoff and maize yield, using FAO's AquaCrop model, calibrated based on field experiments in the Bokole-Karetha watershed, in SW Ethiopia. Experiments were conducted in 2018 and 2019 on three neighboring fields, each comprising plots in triplicate without and with soil bunds. Experimental data from 2018 to 2019, which were average and above average with respect to rainfall, indicate that water availability was sufficient or even in excess for maize production. Soil bunds significantly (p < 0.05) reduced surface runoff, but maize yield did not differ significantly. In plots without soil bunds, the AquaCrop model described surface runoff satisfactorily after slight adjustment of the curve number (related to infiltration capacity) in one of the three fields. Maize yields were reproduced adequately after calibrating soil fertility and adjusting water productivity. After calibration and validation, the AquaCrop model was used to hindcast surface runoff and grain yield from 1999 to 2017, given available climatic data for the region. Hindcasts show that maize yield in the Bokole-Karetha watershed, with its relatively high rainfall, is not significantly affected by rainfall in two of the three fields. In the third field maize yield decreases slightly, but significantly (p < 0.05) with rainfall. In the short run, yield differences between plots with and without soil bunds are not significant. However, eventually high surface runoff from plots without soil bunds are expected to result in unsustainable crop production, due to significant erosion and degradation of the often nutrient-poor soils. Implementation of soil and water management techniques, combined with fertilization, are important to prevent soil degradation and nutrient stress on sloping land.


Assuntos
Conservação dos Recursos Hídricos , Solo , Conservação dos Recursos Naturais , Etiópia , Chuva , Movimentos da Água , Zea mays
11.
J Environ Manage ; 296: 113191, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34246904

RESUMO

Recently, advanced informatics and sensing techniques show promise of enabling a new generation of smart stormwater systems, where real-time sensors are deployed to detect flooding hotspots. Existing stormwater design criteria assume that historical rainfall frequency and intensity are reliable predictors to place real-time sensing devices. However, nonstationarity in rainfall due to climate change violates this assumption by disturbing hydrologic regimes and relocating flooding spots. This paper proposes a novel methodology of combining unsupervised machine learning (Agglomerative Clustering) and analysis of variance (ANOVA) to optimize the sensor placement under uncertain rainfalls. An urban drainage network located in Salt Lake City, Utah, USA, is chosen as the case study to demonstrate the application of the proposed method. Results show that: i) the proposed Agglomerative Clustering and ANOVA integrated approach can efficiently and accurately pinpoint sensor locations for drainage flooding detection; ii) rainfall uncertainty has limited impacts on the number of sensors, but it induces significant effects on sensor locations from the historical period (2000-2009) to the future period (2040-2049). By exploring the effects of climate nonstationarity on sensor placement, this work aims to help engineers and decision-makers better respond to the changing climates and rainfall extremes in urban drainage catchments.


Assuntos
Chuva , Aprendizado de Máquina não Supervisionado , Cidades , Inundações , Incerteza
12.
Water Res ; 202: 117381, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34233250

RESUMO

Mycorrhizae can improve plant growth and drought tolerance by enhancing plant uptake of nutrients and water, which are important targets for biofilters, a common stormwater treatment system. This study evaluated the role of mycorrhizal inoculation on plant growth, photosynthetic efficiency and pollutant removal in two Australian plant species grown in stormwater biofilters. During the establishment period and column study, Ficinia nodosa showed over 80% mycorrhizal colonization, leading to a doubling of shoot and root biomass compared to the control, while Carex appressa showed less than 26% mycorrhizal colonization and no effect on shoot and root biomass. Columns planted with mycorrhizal-inoculated F. nodosa had 5% higher removal of total phosphorus and 10% higher removal of total nitrogen (Figure 5), phosphate (Figure 6), and cadmium (Table 3). Mycorrhizal colonization did not appear to affect plant stress during drought as indicated by similar photosynthetic efficiencies within species. Our results indicate that mycorrhizal inoculation can be highly successful in biofilters while increasing plant growth and nutrient removal, opening opportunities to further study the role of mycorrhizae in enhancing plant drought tolerance and pollutant removal in existing biofiltration systems.


Assuntos
Cyperaceae , Poluentes Ambientais , Micorrizas , Purificação da Água , Austrália , Biomassa , Fósforo , Raízes de Plantas , Chuva , Abastecimento de Água
13.
J Environ Manage ; 297: 113321, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34303939

RESUMO

This research investigated the fate and removal of nitrite (NO2-N), nitrate (NO3-N), orthophosphate (PO4-P), and total suspended solids (TSS) in two bioretention columns, which were designed with three recycled materials. The first column was packed with Recycled Concrete Aggregate (RCA). The second column was a Layered Media (LM), which has layers of RCA with crushed glass and rice husks. The columns were tested under intermittent and frequent operations of synthetic runoff with low and high feed concentrations. The effect of inflow concentration, antecedent dry days (ADD), column age, and the anticipated number of events (EN) was also statistically analyzed on the performance of columns. Depending on column types, nutrient removal was significantly (p < 0.05) increased under frequent flow operations by 26-53% over intermittent. However, TSS removal was notably (p < 0.05) increased by 23-35% under intermittent operations over frequent. Overall, LM showed an increased NO2-N (92 ± 2%) and NO3-N (88% ± 2%) removal under low feed frequent operations and TSS removal (97% ± 2%) under initial intermittent operations. On the contrary, RCA showed a maximum of 99% PO4-P removal under high feed frequent operations. Results showed that the nutrient outflow concentration was found to have a negative correlation with EN and column age and a positive correlation with ADDs throughout the experiments.


Assuntos
Fósforo , Chuva , Nitratos , Nitrogênio , Nutrientes , Reciclagem
14.
Sensors (Basel) ; 21(13)2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201871

RESUMO

During the period 2019-2020, Lake Victoria water levels rose at an alarming rate that has caused various problems in the region. The influence of this phenomena on surface and subsurface water resources has not yet been investigated, largely due to lack of enough in situ measurements compounded by the spatial coverage of the lake's basin, incomplete/inconsistent hydrometeorological data, and unavailable governmental data. Within the framework of joint data assimilation into a land surface model from multi-mission satellite remote sensing, this study employs the state-of-art Gravity Recovery and Climate Experiment follow-on (GRACE-FO) time-variable terrestrial water storage (TWS), newly released ERA-5 reanalysis, and satellite radar altimetry products to understand the cause of the rise of Lake Victoria on the one hand, and the associated impacts of the rise on the total water storage compartments (surface and groundwater) triggered by the extreme climatic event on the other hand. In addition, the study investigates the impacts of large-scale ocean-atmosphere indices on the water storage changes. The results indicate a considerable increase in water storage over the past two years, with multiple subsequent positive trends mainly induced by the Indian Ocean Dipole (IOD). Significant storage increase is also quantified in various water components such as surface water and water discharge, where the results show the lake's water level rose by ∼1.4 m, leading to approximately 1750 gigatonne volume increase. Multiple positive trends are observed in the past two years in the lake's water storage increase with two major events in April-May 2019 and December 2019-January 2020, with the rainfall occurring during the short rainy season of September to November (SON) having had a dominant effect on the lake's rise.


Assuntos
Água Subterrânea , Lagos , Atmosfera , Monitoramento Ambiental , Chuva
15.
Artigo em Inglês | MEDLINE | ID: mdl-34300035

RESUMO

Non-Point Source Pollution (NPS) caused by polluted and untreated stormwater runoff discharging into water bodies has become a serious threat to the ecological environment. Green infrastructure and gray infrastructure are considered to be the main stormwater management measures, and the issue of their cost-effectiveness is a widespread concern for decision makers. Multi-objective optimization is one of the most reliable and commonly used approaches in solving cost-effectiveness issues. However, many studies optimized green and gray infrastructure under an invariant condition, and the additional benefits of green infrastructure were neglected. In this study, a simulation-optimization framework was developed by integrated Stormwater Management Model (SWMM) and Non-dominated Sorting Genetic Algorithm (NSGA-II) to optimize green and gray infrastructure for NPS control under future scenarios, and a realistic area of Sponge City in Nanchang, China, was used as a typical case. Different levels of additional benefits of green infrastructure were estimated in the optimizing process. The results demonstrated that green-gray infrastructure can produce a co-benefit if the green infrastructure have appropriate Value of Additional Benefits (VAB), otherwise, gray infrastructure will be a more cost-effectiveness measure. Moreover, gray infrastructure is more sensitive than green infrastructure and green-gray infrastructure under future scenarios. The findings of the study could help decision makers to develop suitable planning for NPS control based on investment cost and water quality objectives.


Assuntos
Poluição Difusa , China , Cidades , Chuva , Qualidade da Água
16.
Ying Yong Sheng Tai Xue Bao ; 32(6): 1935-1942, 2021 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-34212597

RESUMO

To clarify the changes of water sources for Caragana intermedia plantations at different ages (4, 9, 17 and 31 years) in response to rainfall in the Gonghe Basin of Qinghai Province, China, we used the stable isotope technique to identify δ2H and δ18O compositions of soil water, xylem water, groundwater, and rain water before and after rainfalls. The proportions of different water sources were calculated by the Iso-Source model. The results showed that the δ2H and δ18O compositions of the shallow soil layer (0-40 cm) of all plantations responded significantly to the precipitation. The isotopic values of plant xylem water, soil water, and groundwater of each plantation were spotted on the lower right of the local meteoric water line (LMWL) either before or after rainfall, with lower intercepts and slopes than LMWL and the global meteoric water line (GMWL). The isotopic compositions of xylem water and soil water of C. intermedia plantations were closer to LMWL after rainfall. The 4- and 9-year-old C. intermedia plantations mainly used shallow soil water, the 17-year-old plantation mainly used middle layer soil water (40-90 cm), and the 31-year-old plantation primarily use deep soil water before rainfall. After rainfall, the shallow soil layer became sources of water absorption for all plantations. The utilization proportions of groundwater for all plantations were only 1.8%-11.9%. In general, water sources of different aged C. intermedia plantations showed similar responses to rainfall, by primarily absorbing the shallow soil water supplied by rainfall and reducing the use of groundwater.


Assuntos
Caragana , China , Chuva , Areia , Solo , Água
17.
Ying Yong Sheng Tai Xue Bao ; 32(6): 1951-1962, 2021 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-34212599

RESUMO

The variations of hydrogen and oxygen isotopes in rainfall are critical for understanding the sources of rainfall and the influence of local evaporation. Satellite precipitation products with high time resolution (for instance 1 h) could be helpful for testifying the accuracy of water sources, as it can clearly illustrate the route of cloud movement. In this study, we analyzed the composition of hydrogen and oxygen isotopes in different rainfall events in three stations from 2015 to 2018 along the transection of 38° N latitude from Taihang Mountains to the coastal region in North China, Taihang Mountain Station (mountainous area), Luancheng Station (pre-mountain plain) and Nanpi Station (coastal low plain). By selecting typical rainfall events, water vapor sources and its influence rainfall on hydrogen and oxygen isotopes were analyzed with hourly available CMORPH satellite precipitation products. Results showed that the hydrogen and oxygen isotopes of precipitation were cha-racterized by enrichment in the rainy season and depletion in the dry season. The hydrogen and oxygen isotopes in the rainy season showed a tendency of depletion with the increases of precipitation. The slope and intercept of the fitted relationship of hydrogen and oxygen isotopes in the piedmont region of the mountains were the lowest, indicating that precipitation in the piedmont plain was significantly affected by secondary evaporation fractionation. The effect of evaporation resulted in the largest variations of isotope ratio in the dry year. In the mountainous station, due to the heavy rainfall, large isotopic variation was found in rich precipitation year. Based on the route analysis of sate-llite precipitation products, dominant water vapor in the region was inland and northwest-oriented water vapor, while water vapor in the rainy season was from southwest and from the Pacific Ocean. There was a significant difference in the hydrogen and oxygen isotopes of precipitation in the mountainous and plain stations in 2016, owing to water vapor sources and effects of rainfall for the mountainous and evaporation for plain. The results from HYSPLIT model showed that during the rainstorm on 19th July in 2016, water vapor at the mountainous station was mainly from the southwest, while that in the coastal plain was a mixture of southwest and southeast sources. Overall, our results showed that spatial and temporal variations of hydrogen and oxygen isotopes were controlled by both water sources and evaporation processes along the transection of 38° north latitude in North China.


Assuntos
Hidrogênio , Vapor , China , Monitoramento Ambiental , Hidrogênio/análise , Isótopos de Oxigênio/análise , Oceano Pacífico , Chuva , Estações do Ano
18.
Nat Commun ; 12(1): 4247, 2021 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-34253727

RESUMO

The gymnosperm Welwitschia mirabilis belongs to the ancient, enigmatic gnetophyte lineage. It is a unique desert plant with extreme longevity and two ever-elongating leaves. We present a chromosome-level assembly of its genome (6.8 Gb/1 C) together with methylome and transcriptome data to explore its astonishing biology. We also present a refined, high-quality assembly of Gnetum montanum to enhance our understanding of gnetophyte genome evolution. The Welwitschia genome has been shaped by a lineage-specific ancient, whole genome duplication (~86 million years ago) and more recently (1-2 million years) by bursts of retrotransposon activity. High levels of cytosine methylation (particularly at CHH motifs) are associated with retrotransposons, whilst long-term deamination has resulted in an exceptionally GC-poor genome. Changes in copy number and/or expression of gene families and transcription factors (e.g. R2R3MYB, SAUR) controlling cell growth, differentiation and metabolism underpin the plant's longevity and tolerance to temperature, nutrient and water stress.


Assuntos
Cycadopsida/genética , Clima Desértico , Genoma de Planta , África , Metilação de DNA/genética , Evolução Molecular , Geografia , Meristema/genética , Anotação de Sequência Molecular , Folhas de Planta/genética , Chuva , Análise de Sequência de DNA , Especificidade da Espécie , Transcriptoma/genética
19.
J Environ Manage ; 294: 113108, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34218074

RESUMO

Management and treatment of multi-polluted stormwater in bioretention system have gained significant attraction recently. Besides nutrients, recent source appointment studies found elevated levels of Potentially toxic metal(loid)s (PTMs) and contaminants of emerging concern (CECs) in stormwater that highlighted many limitations in conventional media adsorption-based pollutant removal bioretention strategies. The substantial new studies include biological treatment approaches to strengthen pollutants degradation and adsorption capacity of bioretention. The knowledge on characteristics of plants and their corresponding mechanisms in various functions, e.g., rainwater interception, retention, infiltration, media clogging prevention, evapotranspiration and phytoremediation, is scattered. The microorganisms' role in facilitating vegetation and media, plant-microorganism interactions and relative performance over different functions in bioretention is still unreviewed. To uncover the underneath, it was summarised plant and microbial studies and their functionality in hydrogeochemical cycles in the bioretention system in this review, contributing to finding their interconnections and developing a more efficient bioretention system. Additionally, source characteristics of stormwater and fate of associated pollutants in the environment, the potential of genetical engineered plants, algae and fungi in bioretention system as well as performance assessment of plants and microorganisms in non-bioretention studies to propose the possible solution of un-addressed problems in bioretention system have been put forward in this review. The present review can be used as an imperative reference to enlighten the advantages of adopting multidisciplinary approaches for the environment sustainability and pollution control.


Assuntos
Chuva , Purificação da Água , Interações Microbianas , Plantas , Abastecimento de Água
20.
J Environ Manage ; 295: 113143, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34214790

RESUMO

If biochar is applied to soil or stormwater treatment media, the saturated hydraulic conductivity (K) may be altered, which is a critical property affecting media performance. While a significant number of studies document biochar's effect on a porous medium's K, predictive models are lacking. Herein models are advanced for predicting K for repacked natural soil and engineered media when amended with biochar of various particle sizes and application rates. Experiments were conducted using three repacked natural soils, two uniform sands, and a bioretention medium amended with a wood biochar sieved to seven different biochar particle size distributions and applied at three rates. Experimental measurements showed a strong positive correlation between the interporosity of each medium and K. Across all media, the classic Kozeny-Carman (K-C) model predicted K and the relative change in K because of biochar amendment for each medium best. For soils alone, a recently developed model based on existing pedotransfer functions was optimal. The K-C model error was improved if the particle specific surface area was increased for large biochar particles, which indicates the importance of biochar particle shape on pore structure and K. X-ray Computed Tomography was coupled with pore network modeling to explain the unexpected decrease in K for sands amended with medium and large biochar. While biochar increased interporosity, mean pore radii decreased by ~25% which reduced K. The X-ray measurements and pore network modeling help to explain anomalous results reported for biochar-amended sands in other studies.


Assuntos
Chuva , Purificação da Água , Carvão Vegetal , Solo , Abastecimento de Água
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