Browsing by Autor "Oswaldo Eduardo Ramos Ramos"

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ANÁLISIS MULTIVARIANTE EN LA CLASIFICACIÓN DE SUELOS PARA LA AGRICULTURA EN EL VALLE Y ALTIPLANO BOLIVIANO
(2021) Rolando Mamani Quispe; Oswaldo Eduardo Ramos Ramos; Jorge Chungara Castro; Leonardo Guzmán Alegría; Leonardo Guzmán Alegría
El suelo constituye uno de los recursos más importantes para la vida en el planeta. En ese sentido, este trabajo plantea un análisis discriminante y factorial de los parámetros químicos en diferentes suelos. Se realizó el análisis de 11 parámetros fisicoquímicos en muestras de suelos provenientes de dos comunidades: Yamora y Viacha, ambas localidades ubicadas en el Departamento de La Paz (Bolivia) y con características diferentes de suelos en base a su clasificación de suelos para uso en la agricultura. Se ha encontrado que la función discriminante está representada por cinco parámetros: Contenido de Nitrógeno, Fósforo, Na+, K+ y Mg2+. El análisis factorial muestra que los componentes principales son funciones de dos grupos de parámetros, uno con correlación positiva y otro con correlación negativa. Estas funciones permiten caracterizar los suelos y su fertilidad química.
ARSENIC AND OTHER GEOGENIC CONTAMINANTS IN THE HYDROLOGIC AND HYDROGEOLOGICAL SYSTEM OF THE BOLIVIAN ALTIPLANO
(Geological Society of America, 2023) Prosun Bhattacharya; Lizángela Huallpara; Mauricio Ormachea; Oswaldo Eduardo Ramos Ramos
Arsenic mobility in hydrogeologic system of Bolivian Altiplano: Status and comparison of the Lower Katari and Southern Poopó Basins
(2024) Israel Quino Lima; Mauricio Ormachea; Oswaldo Eduardo Ramos Ramos; Javier Quintanilla; Jyoti Prakash Maity; Ahmad Arslan; Prosun Bhattacharya
Water resource in LKB (Lower Katari Basin) and SPB (Southern Poopó Basin) [TDPS (Lake Titicaca – Desaguadero River – Lake Poopó – Salt Flat of Coipasa) system] the southeastern part of Lake Titicaca and Lake Poopó in Bolivian Altiplano are contaminated with high concentrations of arsenic (As) (>10 μg/L) compared to the WHO and NB-512 guideline. Studied regions are characterized by a semiarid climate, slow hydrological flow, with geological formations of volcanic origin including brines and mineral deposits. The investigation focused on evaluating the present status and comparison of the geochemical processes of As in relation to the sources and mobilization in groundwater (GW) in LKB and SPB. Groundwater (GW), surface water (SW) and sediment samples were collected from both basins. The elevated concentration of As (LKB: 0.8–288 μg/L and SPB: 2.6–207 μg/L), boron (B) (LKB: 96–2473 μg/L and SPB: 507–4359 μg/L), manganese (Mn) (LKB: 0.6–7259 μg/L) and salinity (LKB: 125–11740 μS/cm) were observed in water compared to the WHO limit and is a serious concern about the GW quality for human consumption. The mineralization of GW is governing by the dissolution and exchange process of bases and anthropogenic generated solids and liquids effects the surface water quality in LKB as well as river bank communities. The spatial distribution of As was attributed to the geology of both the basins and the heterogeneously distributed evaporites in the sediments. The concentrations of As are found in alluvial sediments in northern region of LKB and “PACK belt” (an approximately 25 km long belt stretching along the southern shores of the Lake Poopó, between the villages of Pampa Aullagas and Condo K) in SPB, where iron (Fe) and aluminum (Al) oxides as well as hydroxides are the most predominant mineral phases as potential sorbents of As.
Complementarity of Sentinel-1 and Sentinel-2 Data for Soil Salinity Monitoring to Support Sustainable Agriculture Practices in the Central Bolivian Altiplano
(Multidisciplinary Digital Publishing Institute, 2024) J. W. Sirpa-Poma; Frédéric Satgé; Ramiro Pillco Zolá; Eléonore Resongles; María Eufemia Pérez-Flores; M. G. Flores Colque; Jorge Molina‐Carpio; Oswaldo Eduardo Ramos Ramos; Marie‐Paule Bonnet
Soil salinization will affect 50% of global cropland areas by 2050 and represents a major threat to agricultural production and food sovereignty. As soil salinity monitoring is costly and time consuming, many regions of the world undertake very limited soil salinity observation (in space and time), preventing the accurate assessment of soil salinity hazards. In this context, this study assesses the relative performance of Sentinel-1 radar and Sentinel-2 optical images, and the combination of the two, for monitoring changes in soil salinity at high spatial and temporal resolution, which is essential to evaluate the mitigation measures required for the sustainable adaptation of agriculture practices. For this purpose, an improved learning database made of 863 soil electrical conductivity (i.e., soil salinity) observations is considered for the training/validation step of a Random Forest (RF) model. The RF model is successively trained with (1) only Sentinel-1, (2) only Sentinel-2 and (3) both Sentinel-1 and -2 features using the Genetic Algorithm (GA) to reduce multi-collinearity in the independent variables. Using k-fold cross validation (3-fold), overall accuracy (OA) values of 0.83, 0.88 and 0.95 are obtained when considering only Sentinel-2, only Sentinel-1 and both Sentinel-1 and -2 features as independent variables. Therefore, these results highlight the clear complementarity of radar (i.e., Sentinel-1) and optical (i.e., Sentinel-2) images to improve soil salinity mapping, with OA increases of approximately 10% and 7% when compared to Sentinel-2 and Sentinel-1 alone. Finally, pre-sowing soil salinity maps over a five-year period (2019–2023) are presented to highlight the benefit of the proposed procedure to support the sustainable management of agricultural lands in the context of soil salinization on a regional scale.
Contrasting controls on hydrogeochemistry of arsenic-enriched groundwater in the homologous tectonic settings of Andean and Himalayan basin aquifers, Latin America and South Asia
(Elsevier BV, 2019) Poulomee Coomar; Abhijit Mukherjee; Prosun Bhattacharya; Jochen Bundschuh; Swati Verma; Alan E. Fryar; Oswaldo Eduardo Ramos Ramos; Mauricio Ormachea; Saibal Gupta; Chandan Mahanta
EVALUACIÓN REGIONAL DE LOS RECURSOS SUBSUPERFICIALES DE LA SUBCUENCA DEL LAGO POOPÓ
(Universidad Autónoma del Estado de México, 2011) Maggy Martha L.A. Niura; Oswaldo Eduardo Ramos Ramos; Jorge Quintanilla; M.E. García; Elena Teresa Graterol Blanco; Liliana Carolina Machado Flores
"La evaluación de los Recursos subsuperficiales de la subcuenca del Lago Poopó, se realizó durante los años 2007 y2008, dentro del proyecto CAMINAR “Gestión de cuencas con influencia minera en zonas áridas y semiáridas deAmérica del Sur”. Dentro de este marco el siguiente trabajo tuvo por objetivo la evaluación de los recursossubsuperficiales (pozos) de la subcuenca del Lago Poopó para establecer alternativas de manejo de recursos hídricosen diferentes regiones de la subcuenca y promover dentro de los municipios criterios de acceso seguro al agua en suscomunidades. El análisis que se detalla corresponde a la identificación de regiones con actividades socioeconómicasdiferentes y con usos diferentes de agua. De esta manera en la Región 1, se recomienda priorizar el establecimientode áreas de influencia de los pozos para limitar posibles fuentes de contaminación orgánica tanto en los pozosfamiliares como comunales. En la región 2, es prioridad el desarrollo de estudios hidrogeológicos para determinarlas zonas en que se tenga acceso seguro al agua. En la región 3 se debe desarrollar un programa integral de manejode suelos paralelo a los programas de dotación segura de agua para consumo, considerando medidas para la gestiónsostenible de prácticas agrícolas. En la región 4 se recomienda tomar las consideraciones respectivas paraimplementar métodos básicos y económicos para eliminar el arsénico. En la región 5 a diferencia de la 4, losprogramas a desarrollar como prioridad son específicos en tratamiento de aguas subsuperficiales de consumo y riego para eliminar el arsénico."
Fractionation of heavy metals and assessment of contamination of the sediments of Lake Titicaca
(Springer Science+Business Media, 2013) Luis Fernando Cáceres Choque; Oswaldo Eduardo Ramos Ramos; Sulema N. Valdez Castro; Rigoberto Rogelio Choque Aspiazu; Rocío G. Choque Mamani; Samuel G. Fernández Alcazar; Ondra Šráček; Prosun Bhattacharya
Geochemical mechanisms of natural arsenic mobility in the hydrogeologic system of Lower Katari Basin, Bolivian Altiplano
(Elsevier BV, 2020) Israel Quino Lima; Oswaldo Eduardo Ramos Ramos; Mauricio Ormachea; María Isabel Chambi Tapia; Jorge Quintanilla Aguirre; Ahmad Arslan; Jyoti Prakash Maity; Md. Tahmidul Islam; Prosun Bhattacharya
Geochemical processes controlling mobilization of arsenic and trace elements in shallow aquifers and surface waters in the Antequera and Poopó mining regions, Bolivian Altiplano
(Elsevier BV, 2014) Oswaldo Eduardo Ramos Ramos; Tobías S. Rötting; Megan French; Ondra Šráček; Jochen Bundschuh; Jorge Quintanilla; Prosun Bhattacharya
HEAVY METALS IN AQUATIC PLANTS AND THEIR RELATIONSHIP TO CONCENTRATIONS IN SURFACE WATER, GROUNDWATER AND SEDIMENTS - A CASE STUDY OF POOPÓ BASIN, BOLIVIA
(Lund University, 2005) M.E. García; Jochen Bundschuh; Oswaldo Eduardo Ramos Ramos; J. Quinatanilla; Kenneth M. Persson; Lars Bengtsson; Ronny Berndtsson
"The uptake of the heavy metals Cd, Zn, Pb, As, and Fe by aquatic plants — thereby entering the human food chain — was studied in the Poopó basin, located in the semiarid, central Andean highland of Bolivia. At twenty sites around Poopó and Uru-Uru lakes, samples of aquatic plants, sediments, surface water and groundwater were taken. The spatial distribution of heavy metals indicate that most of the Cd and Pb influx into the semiarid Poopó basin results from mining activities and subordinate from geothermal activities, which are both located in the NE of Poopó basin. Also, arsenic concentrations are of similar magnitudes, released from mining activities and natural weathering of As-bearing rocks and predominantly observed in the W, SE, and S of Poopó basin. In the aquatic plants, concentrations of Cd, Zn, Pb and As were found in the ranges 0.0–45.0, 0–197, 0–858, and 83–943 mg/kg, respectively. The heavy metal concentrations found in aqueous plants are correlated to varying extents to the corresponding heavy metal concentrations in sediments, surface water and groundwater. High Cd and Pb concentration in aquatic plants sampled within Poopó Lake (15–23 and 858–936 mg/kg, respectively) correlate strongly with high Cd and Pb concentrations of its alkaline water (1.37–1.51 and 0.36–0.38 mg/L, respectively) as well as with high Cd and Pb concentrations in the lake sediments (20–25 and 210–260 mg/kg, respectively). However, at other sampling sites of the basin this correlation of Cd does not always exist. For As and Zn, no correlation could be found between the respective concentrations in aquatic plants, sediments, surface water and groundwater. There is no correlation between Cd, Zn, and Pb concentrations in surface water and groundwater. This shows that these heavy metals are predominantly fixed in the sediments and taken up by plants and/or transported as sediment load to Poopó Lake (Cd, Zn, and Pb cations are only stable in larger amounts under acidic conditions, e.g. in the acidic rivers influenced by mining activities, and nearby groundwater bodies, which are found in the NE of Poopó basin). In contrast the anions of arsenic are more soluble in surface water and groundwater with a neutral or slightly alkaline pH."
Hydrochemical assessment with respect to arsenic and other trace elements in the Lower Katari Basin, Bolivian Altiplano
(Elsevier BV, 2018) Israel Quino Lima; Mauricio Ormachea; Oswaldo Eduardo Ramos Ramos; Prosun Bhattacharya; R. Choque; Jorge Quintanilla Aguirre; Ondra Šráček
HYDROCHEMISTRY AND SPATIAL VARIATION OF ARSENIC, BORON AND OTHER TRACE ELEMENTS IN WATER BODIES IN VOLCANIC ZONE OF THE SUD LIPEZ PROVINCE, BOLIVIAN ALTIPLANO
(Geological Society of America, 2023) Maria Chambi Tapia; Israel Quino; Mauricio Ormachea; Oswaldo Eduardo Ramos Ramos; Prosun Bhattacharya
Hydrogeochemical and nitrate isotopic evolution of a semiarid mountainous basin aquifer of glacial-fluvial and paleolacustrine origin (Lake Titicaca, Bolivia): the effects of natural processes and anthropogenic activities
(Springer Science+Business Media, 2022) Gabriela Patricia Flores Avilés; Lorenzo Spadini; Elisa Sacchi; Yvan Rossier; Joël Savarino; Oswaldo Eduardo Ramos Ramos; Céline Duwig
Hydrogeochemical and nitrate isotopic indicators of vulnerability in the Katari-Lago Menor basin-aquifer, Lake Titicaca-Bolivia
(2021) Gabriela Patricia Flores Avilés; Céline Duwig; Elisa Sacchi; Lorenzo Spadini; Joël Savarino; Oswaldo Eduardo Ramos Ramos
&lt;p&gt;In the semi-arid Bolivian Altiplano, the Katari and Lago Menor Basin, ranging between 6000 and 3800 m a.s.l. in altitude, hosts a major aquifer in Quaternary sediments of fluvioglacial and paleolacustrine origin. This basin supports a population of over 1.2 million of inhabitants and the largest city in the Altiplano, El Alto, one of the Latin America&amp;#8217;s fastest growing cities in the 1980s. This rapid urban growth was accompanied by minimal land planning, and lack of basic infrastructure and environmental policies. In addition, the region is greatly affected by climate change, causing the glaciers to shrink. A multi-tracer approach was used to understand the main hydrogeochemical processes taking place along the groundwater flow, and to evaluate the impact of anthropogenic activities on groundwater quality and nitrate concentrations. In the upper part of the aquifer (above 4000m), in the Piedmont subsystem, siliciclastic and evaporitic rocks host groundwater of high quality. Here, groundwater chemistry is dominated by silicate weathering leading to a Ca(Mg)-HCO&lt;sub&gt;3&lt;/sub&gt; facies, low nitrate concentrations (&lt;3.2 mgL&lt;sup&gt;-1&lt;/sup&gt;), and low mineralization. At lower altitude, the anthropogenic impact is revealed by the increase in NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; concentrations, reaching up to 35.6 mg L&lt;sup&gt;-1&lt;/sup&gt;.&amp;#160; Nitrate stable isotopes allowed discriminating three main nitrate contributions: &amp;#160;leaching from areas influenced by manure piles, use of synthetic N fertilizers, and leakage from sewage collection pipes. Natural attenuation of nitrate occurs when fresh groundwater mixes with brackish groundwater of evaporitic origin. On the other hand, in the lacustrine plain (~3860 to 3810 m a.s.l), the groundwater geochemistry is dominated by evaporite dissolution and calcite precipitation, while nitrate originates from nitrification of synthetic fertilizers. This first hydrogeochemical study of one of the major groundwater systems in the Northern Altiplano is an important step towards a better management of this crucial water resource for the sustainable development of this region.&lt;/p&gt;&lt;p&gt;Fundings :&lt;/p&gt;&lt;p&gt;The present study was undertaken with the financial support of the Plurinational State of Bolivia provided through the Program &amp;#8220;100 Scholarships for Postgraduate Education within the Framework of Technological and Scientific Sovereignty&amp;#8221;, Supreme Decree 2100 (1 September 2014), and partly funded by LABEX OSUG@2020, ANR grant no.ANR-10-LABX-56 (financed by the Future Investments programme launched by the French government and implemented by the ANR).&lt;/p&gt;
HYDROGEOCHEMICAL CHARACTERIZATION AND QUALITY ASSESSMENT OF GROUNDWATER AND SURFACE WATER WITHIN THE SAJAMA NATIONAL PARK AND ITS AREAS OF INFLUENCE, BOLIVIAN ALTIPLANO
(Geological Society of America, 2024) Maria Chambi Tapia; Israel Quino; Israel Quino; Mauricio Ormachea; Mauricio Ormachea; Oswaldo Eduardo Ramos Ramos; Oswaldo Eduardo Ramos Ramos; Prosun Bhattacharya; Prosun Bhattacharya
Hydrogeochemical contrasts in the shallow aquifer systems of the Lower Katari Basin and Southern Poopó Basin, Bolivian Altiplano
(Elsevier BV, 2020) Israel Quino Lima; Mauricio Ormachea; Oswaldo Eduardo Ramos Ramos; Jorge Quintanilla Aguirre; Jyoti Prakash Maity; Ahmad Arslan; Prosun Bhattacharya
Drinking water sources in the southeastern part of Lake Titicaca (Lower Katari Basin: LKB) and the southern part of Lake Poopó (Southern Poopó Basin: SPB) have high concentrations of arsenic (As), >10 μg/L compared to the WHO and NB-512 guideline value. These regions belong to the Bolivian Altiplano and are characterized by a semiarid climate, slow hydrological flow, with geological formations of volcanic origin, in addition to brines and other mineral deposits. The present study is focused on comparing the geochemical processes of As in relation to the sources and mobilization in groundwater (GW) in LKB and SPB. Groundwater (GW), surface water (SW) and sediment samples were collected from both basins. The As (LKB: 0.8–288 μg/L and SPB: 2.6–207 μg/L), boron (B) (LKB: 96–2473 μg/L and SPB: 507–4359 μg/L), manganese (Mn) (LKB: 0.6–7259 μg/L) and salinity (LKB: 125–11740 μS/cm) were found to be higher than the WHO guideline values, which is a serious concern about the GW quality for human consumption. The dissolution and exchange of bases are the processes that govern the mineralization of GW. Load of solids and liquids of anthropogenic origin in surface water (LKB) represents an environmental problem for communities on river banks. The spatial distribution of As was attributed to the geology of both the basins and the heterogeneously distributed evaporites in the sediments. The highest As concentrations are found in alluvial sediments of the northern region of LKB and “PACK belt” (an approximately 25 km long belt stretching along the southern shores of the Lake Poopó, between the villages of Pampa Aullagas and Condo K) in SPB. Sequential extraction of sediment and mineral saturation indices indicate that iron (Fe) and aluminum (Al) oxides as well as hydroxides are the most predominant mineral phases as potential sorbents of As.
Método para la determinación de arsénico en suelos agrícolas mediante espectrometría de absorción atómica con horno de grafito de fuente continua de alta resolución HR-CS-GFAAS
(2024) Romel Emil Aruquipa Buitre; Leonardo Guzmán Alegría; Oswaldo Eduardo Ramos Ramos; Instituto de Investigaciones Químicas IIQ, Universidad Mayor de San Andrés UMSA, Av. Villazón N° 1995, La Paz, Bolivia, 0201-0220, iiq@umsa.bo; Oswaldo Eduardo Ramos Ramos; Instituto de Investigaciones Químicas IIQ, Universidad Mayor de San Andrés UMSA, Av. Villazón N° 1995, La Paz, Bolivia, 0201-0220, iiq@umsa.bo
Se optimizaron las condiciones para la determinación de arsénico pseudo-total en muestras de suelos agrícolas mediante espectrometría de absorción atómica con horno de grafito de fuente continua de alta resolución HR-CS-GFAAS, previa digestión en agua regia en horno de microondas. Se configuró la longitud de onda de 193.696 nm que corresponde a la línea de As y se realizó un diseño experimental para optimizar la sensibilidad instrumental de análisis de As entre las variables: temperatura de pirolisis, temperatura de atomización y el volumen de muestra y modificador. La metodología desarrollada mostró que las condiciones óptimas fueron 1300°C de temperatura de pirólisis y 2250°C de atomización; en una relación de volumen de 5:1 μL de muestra y modificador, respectivamente. Para categorizar el método optimizado como validado, se verificó la linealidad, exactitud y precisión. El Límite de Detección (LD) y el Límite de cuantificación (LC) tienen como valor 4.45 μg/L y 14.06 μg/L, respectivamente.
Multivariate Analysis in the Characterization and Classification of Soils
(IntechOpen, 2023) Oswaldo Eduardo Ramos Ramos; Leonardo Guzmán Alegría
Soil is a fundamental natural resource in the balance for the ecosystems as well as for agriculture, food, and housing. The soil is very susceptible to changes in its structure due to contamination or degradation of anthropogenic origin. Therefore, its evaluation, whether for environmental purposes or as an agricultural or housing resource, must be carried out in depth. This evaluation comprises the analysis of multiple physical, physicochemical and chemical-biological parameters. However, due to these multiple parameters, the use of multivariate statistical methods becomes necessary. In this chapter, the soil data analysis was performed by the method of Principal Components Analysis for a reduction of dimensions and, to carry out a better interpretation of results. This method was applied to carry out a characterization and classification of soil samples. The analysis was performed with data obtained from soil samples from the Bolivian Altiplano. The results show the potential of the principal component of the method in processing data.
OPTIMIZACIÓN DEL MÉTODO DE DIGESTIÓN ÁCIDA EN SISTEMA DE MICROONDAS PARA LA DETERMINACIÓN DE CONCENTRACIONES PSEUDOTOTALES DE Fe, Mn Y Zn EN SEDIMENTOS DE LA CUENCA KATARI BAJO, LA PAZ, BOLIVIA
(2021) Delia M. Cori Condori; María Isabel Chambi Tapia; Leonardo Guzmán Alegría; Jorge Quintanilla Aguirre; Oswaldo Eduardo Ramos Ramos
Los sedimentos son considerados reservorios de elementos traza donde, son transportados por agua de ríos y depositados en la parte de baja de las cuencas. El trabajo presenta la optimización del un método de digestión ácida en un sistema de microondas para determinar elementos traza de Fe, Mn y Zn en sedimentos a profundidades de PK9-1 (0-0,5) m, PK9-2 (0,5-2) m y PK9-3 (2-2,7) m en un piezómetro seleccionado al azar de un total de 17 piezómetros. Además, se han utilizado los materiales de referencia certificado MRC MESS-3 de sedimentos y MRC C17-2 de suelos para un control de calidad del método de digestión acida. Para la cuantificación se ha empleado la técnica de Espectrometría de Absorción Atómica a la flama (FAAS) y para la interpretación estadística de los datos se aplicó un diseño factorial 2x2 (ANOVA). Los procedimientos de extracción involucran variaciones de volumen 3:3 y 3:1 mL de HNO3: HCl, potencia 300/600 W y 100/300/700 W y con o sin la adición de H2O2. Los resultados del MRC MESS-3 muestran que al variar las condiciones de extracción, éstas no afectan considerablemente las concentraciones de Fe, Mn y Zn. Se encontró que el procedimiento óptimo es 3 horas, sin H2O2 y con 3:1 mL HNO3/HCl con una diferencia significativa mínima entre el valor experimental y el valor de referencia. Para un MRC C17-2 se tienen errores que superan el 10% donde existen diferencias significativas entre el valor experimental y el valor de referencia para Zn y Mn. Por otro lado, el PK9-1 (0-0,5) m y PK9-3 (0,5-2) m muestran una P > 0,05 para Fe indicando diferencia significativa en las concentraciones promedio, y una P < 0,05 para Zn/Mn indicando que no existe diferencias significativas en las concentraciones promedio al variar las condiciones de volumen y potencia. Así también PK9-2 (0,5-2) m muestra P > 0,05 para Zn/Fe indicando una diferencia significativa en las concentraciones promedio al variar las condiciones de volumen, potencia y con o sin la adición de H2O2. Para Mn, la P < 0,05 indicando que no existe diferencia significativa en las concentraciones promedio. Por tanto, al variar cantidades de volumen, potencia y H2O2 no alteran considerablemente las concentraciones de los elementos traza y por ende las concentraciones de elementos traza varían con la profundidad de acuerdo a las características litológicas de los sedimentos.
Sources and behavior of arsenic and trace elements in groundwater and surface water in the Poopó Lake Basin, Bolivian Altiplano
(Springer Science+Business Media, 2011) Oswaldo Eduardo Ramos Ramos; Luis Fernando Cáceres; Mauricio Ormachea; Prosun Bhattacharya; Israel Quino; Jorge Quintanilla; Ondra Šráček; Roger Thunvik; Jochen Bundschuh; M.E. García