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  1. Article ; Online: Spatial Dynamics of the Shore Coverage within the Zone of Influence of the Chambo River, Central Ecuador

    Julie Echeverría-Puertas / Magdy Echeverría / Franklin Cargua / Theofilos Toulkeridis

    Land, Vol 12, Iss 180, p

    2023  Volume 180

    Abstract: The predominant aim of the current study was to evaluate the spatial dynamics of the riparian coverage of the area of influence of the Chambo River in the area of the river’s source (middle-high basin), between 2500 and 3000 m.a.s.l. For its execution, ... ...

    Abstract The predominant aim of the current study was to evaluate the spatial dynamics of the riparian coverage of the area of influence of the Chambo River in the area of the river’s source (middle-high basin), between 2500 and 3000 m.a.s.l. For its execution, Landsat 7 images from the year 2000, RapidEye from the year 2009, and Spot 6 from the year 2019 were used in the time range of 2000–2009 and 2009–2019. These were subjected to supervised classification by applying the maximum likelihood algorithm, identifying five classes of soil cover, being pasture, crops, soil-remnants of paramo, forest, and anthropic. The classification results were validated by calculating the precision measures and the kappa index. With the use of cross-tabulation matrices, the gains, losses, and persistence in the two periods studied were identified. There, it was determined that, in the first study period, the soil cover-paramo remnants presented the highest percentage of loss (26.70%), the crop cover the highest percentage of gain (28.91%), and in the second period, the crop class presented the highest percentages of losses (18.94%) and gains (17.29%). The cartographic projection of the area for the year 2030 predicts that the areas anthropic category will increase by 1.27%, that of forest will decrease by 1.19%, that of soil-remnants of paramo will gain 0.79%, and crop and pasture cover will decrease by 0.45% and 0.43%, respectively. The results obtained allow for the transitions between coverages to be attributed to population growth, afforestation, reforestation, deforestation and agricultural activities, volcanic eruptions, land colonization, and expansion of agricultural activity. Complementary studies are recommended that involve livelihoods and water quality, which facilitate the identification of vulnerable areas to propose adaptation, prevention, and/or restoration measures.
    Keywords Chambo River ; Andean riparian area ; spatial dynamics ; land cover ; supervised classification ; cartographic projection ; Agriculture ; S
    Subject code 910
    Language English
    Publishing date 2023-01-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Vulnerabilidad a nivel de ecosistema de Páramo frente al Cambio Climático en la zona de Igualata Parroquia San Isidro, Cantón Guano Provincia de Chimborazo

    Magdy Echeverría / Carlos Rosero / Lelys Bravo

    Revista del Instituto de Investigación de la Facultad de Minas, Metalurgia y Ciencias Geográficas, Vol 20, Iss 39, Pp 137-

    2017  Volume 148

    Abstract: El presente estudio tiene como propósito establecer un índice y un nivel de vulnerabilidad relacionado con el ecosistema de páramo ante los efectos del Cambio Climático a través de la identificación de las diferentes amenazas que podrían ocasionar un ... ...

    Abstract El presente estudio tiene como propósito establecer un índice y un nivel de vulnerabilidad relacionado con el ecosistema de páramo ante los efectos del Cambio Climático a través de la identificación de las diferentes amenazas que podrían ocasionar un impacto en este sistema. Para lograr un análisis fiable y conciso se delimitó la zona de estudio mediante tres enfoques geográficos: ecosistema, datos recolectados de carbono y características limítrofes, los datos tanto de temperatura y precipitación actual son generados en base a modelos climáticos implementados por el Ministerio del Ambiente a través de las estaciones meteorológicas validadas a nivel nacional a cargo del Instituto Nacional de Meteorología e Hidrología, además se logra en el presente estudio analizar la variable precipitación a través de la estación meteorológica M390 Urbina. Otra de las variables que se considera en el presente estudio es el probable clima futuro donde se utilizan datos proporcionados por el Modelo Climático Japonés TL959. La vulnerabilidad en este estudio está enfocada en el análisis de 8 indicadores bajo la conceptualización de los 3 elementos de vulnerabilidad, es decir; Exposición, Sensibilidad y Capacidad de Adaptación. Es necesario tomar en cuenta que se determina de igual manera el impacto potencial como parte de este proceso. Los indicadores están enfocados bajo el análisis de escalas de 1-3 para el análisis de los elementos de vulnerabilidad y de 0-100 para el índice de Vulnerabilidad Total. El estudio determinó una vulnerabilidad en el ecosistema equivalente a 62,5 lo que se considera como un nivel de vulnerabilidad alta.
    Keywords vulnerabilidad ; ecosistema de páramo ; adaptación ; cambio climático ; stock de carbono ; Mining engineering. Metallurgy ; TN1-997 ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Geography (General) ; G1-922
    Language Spanish
    Publishing date 2017-07-01T00:00:00Z
    Publisher Universidad Nacional Mayor de San Marcos
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Potential of Zantedeschia aethiopica L. for rehabilitation of soil contaminated with hexavalent chromium in high Andean areas of Ecuador

    Andrés Agustìn Beltrán Dávalos / Carlos Rosero Erazo / Franklin Cargua Catagña / Magdy Echeverría

    Acta Agronómica, Vol 68, Iss 2, Pp 92-

    2019  Volume 98

    Abstract: Zantedeschia aethiopica is one of the ornamental vascular plants, protective of wetlands and fluvial systems with greater distribution in the Andean zone of Ecuador. The objective of the research was to evaluate the toxic effect of Chromium VI in ... ...

    Abstract Zantedeschia aethiopica is one of the ornamental vascular plants, protective of wetlands and fluvial systems with greater distribution in the Andean zone of Ecuador. The objective of the research was to evaluate the toxic effect of Chromium VI in Zantedeschia aethiopica L. recognizing its limitations as a bioindicator plant, for which specific and non-specific physiological effects were determined such as relative seed germination (RSG), root elongation relative (ERR) and germination index in experimental units exposed to concentrations of 0, 50, 100, 200 and 300 mg.kg-1 of Cr+6 during 168 hours; then monitoring the growth of the plant grown in contaminated soil under the concentrations of the germination stage under semi-controlled conditions of temperature, humidity and field capacity for 20 weeks; in the postharvest, analysis of the concentrations of the metal in the aerial zone of the plant (stem, leaves, and flowers) and root were carried out for the determination of the translocation index (TI) and soil for the evaluation of the Bioconcentration Factor (BCF). The results indicated the toxicity of Cr+6 in concentrations of 100, 200 and 300 mg.kg-1 with similar statistical behavior (P≤0,05) in the germination stage and with non-specific physiological effects on the growth of the plant at concentrations of 200 and 300 mg.kg-1 showing absent flowering, dwarfing and wilting. With the obtained results and applying a bivariate Probit statistical analysis with a 95% reliability, the LC50 was determined in 118.96 mg.kg-1 of Cr+6 limit in which the plant can be a bioaccumulative and bioindicator species at concentrations higher than 200 mg.kg-1
    Keywords Relative radicular elongation ; hexavalent chromium ; germination index ; Zantedeschia aethiopica L ; Bioconcentration factor ; Agriculture ; S
    Subject code 580
    Language English
    Publishing date 2019-04-01T00:00:00Z
    Publisher Universidad Nacional de Colombia
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article: Single chamber microbial fuel cell (SCMFC) with a cathodic microalgal biofilm: A preliminary assessment of the generation of bioelectricity and biodegradation of real dye textile wastewater

    Logroño, Washington / Abudukeremu Kadier / Celso Recalde / Gábor Rákhely / Gladys Urquizo / Magdy Echeverría / Mario Pérez

    Chemosphere. 2017 June, v. 176

    2017  

    Abstract: An air exposed single-chamber microbial fuel cell (SCMFC) using microalgal biocathodes was designed. The reactors were tested for the simultaneous biodegradation of real dye textile wastewater (RTW) and the generation of bioelectricity. The results of ... ...

    Abstract An air exposed single-chamber microbial fuel cell (SCMFC) using microalgal biocathodes was designed. The reactors were tested for the simultaneous biodegradation of real dye textile wastewater (RTW) and the generation of bioelectricity. The results of digital image processing revealed a maximum coverage area on the biocathodes by microalgal cells of 42%. The atmospheric and diffused CO2 could enable good algal growth and its immobilized operation on the cathode electrode. The biocathode-SCMFCs outperformed an open circuit voltage (OCV), which was 18%–43% higher than the control. Furthermore, the maximum volumetric power density achieved was 123.2 ± 27.5 mW m−3. The system was suitable for the treatment of RTW and the removal/decrease of COD, colour and heavy metals. High removal efficiencies were observed in the SCMFCs for Zn (98%) and COD (92–98%), but the removal efficiencies were considerably lower for Cr (54–80%). We observed that this single chamber MFC simplifies a double chamber system. The bioelectrochemical performance was relatively low, but the treatment capacity of the system seems encouraging in contrast to previous studies. A proof-of-concept experiment demonstrated that the microalgal biocathode could operate in air exposed conditions, seems to be a promising alternative to a Pt cathode and is an efficient and cost-effective approach to improve the performance of single chamber MFCs.
    Keywords air ; biodegradation ; bioelectricity ; biofilm ; carbon dioxide ; chemical oxygen demand ; chromium ; color ; cost effectiveness ; digital images ; electrodes ; fabrics ; heavy metals ; image analysis ; microalgae ; microbial fuel cells ; wastewater ; zinc
    Language English
    Dates of publication 2017-06
    Size p. 378-388.
    Publishing place Elsevier Ltd
    Document type Article
    ZDB-ID 120089-6
    ISSN 1879-1298 ; 0045-6535 ; 0366-7111
    ISSN (online) 1879-1298
    ISSN 0045-6535 ; 0366-7111
    DOI 10.1016/j.chemosphere.2017.02.099
    Database NAL-Catalogue (AGRICOLA)

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