4 research outputs found
Chronometry of the Neolithisation Process in the Lower Valey of Mundo River
En los últimos años nuestro proyecto de investigación multidisciplinar está implementando un programa de dataciones numéricas en diferentes yacimientos que albergan niveles arqueológicos relacionados con la neolitización de los Campos de Hellín y la cuenca baja del río Mundo. En este trabajo se presentan todas las fechas obtenidas, algunas de ellas inéditas, que proceden de la aplicación de los métodos del radiocarbono, termoluminiscencia y racemización de aminoácidos sobre muestras orgánicas e inorgánicas de distinta naturaleza. Las excavaciones efectuadas en los abrigos de Cueva Blanca, Pico Tienda III y Acebuchal nos están permitiendo desvelar una secuencia de poblamiento en este espacio geográfico desde el IX hasta el VI milenio cal BP. Anteriormente, no se contaba con evidencias arqueológicas de estos periodos, planteándose erróneamente un vacío poblacional para esta zona que, por otra parte, presenta una situación geoestratégica privilegiada al ser vía natural de comunicación entre la meseta y la costa mediterránea y emplazarse igualmente dentro de los corredores naturales del Prebético externo que conectan las sierras del norte de Alicante y las del Segura y Cazorla.In recent years our multidisciplinary research project is implementing a program of numerical dating in different sites that host archaeological levels related to the neolithisation of Campos de Hellín and the lower basin of the Mundo River. In this paper we present all the dates obtained, some of them unpublished, that come from the application of radiocarbon, thermoluminescence and amino acid racemization methods on organic and inorganic samples of different nature. Excavations carried out in the shelters of Cueva Blanca, Pico Tienda III and Acebuchal are allowing us to unveil a sequence of settlement in this geographical space from the 9th to the 6th millennium cal BP Previously, there was no archaeological evidence of these periods, mistakenly posing a population gap for this area, which, on the other hand, presents a privileged geostrategic situation as it is a natural route of communication between the plateau and the Mediterranean coast and also lies within the natural corridors of the external Prebético that connect the mountain ranges of the north of Alicante and those of the Segura and Cazorla.info:eu-repo/semantics/publishedVersio
Streamflow Variability in Colombian Pacific Basins and Their Teleconnections with Climate Indices
[EN] Oceanic-atmospheric phenomena of different time scales concurrently might affect the streamflow in several basins around the world. The Atrato River Basin (ARB) and Pa-Ha River Basin (PRB) of the Colombian Pacific region are examples of such basins. Nevertheless, the relations between the streamflows in the ARB and PRB and the oceanic-atmospheric factors have not been examined considering different temporal scales. Hence, this article studies the relations of the climate indices and the variability of the streamflows in the ARB and PRB at interannual and decadal timescales. To this, the streamflow variability modes were obtained from the principal component analysis (PCA); furthermore, their linear dependence with indices of the El Nino/Southern Oscillation (ENSO), precipitation (PRP), the Choco low-level jet (CJ), and other indices were quantified through (a) Pearson and Kendall's tau correlations, and (b) wavelet transform. The PCA presented a single significant mode for each basin, with an explained variance of around 80%. The correlation analyses between the PC1s of the ARB and PRB, and the climate indices showed significant positive (negative) high correlations with PRP, CJ, and Southern Oscillation Index (SOI) (ENSO indices). The wavelet coherence analysis showed significant coherencies between ENSO and ARB: at interannual (2-7 years) and decadal scale (8-14), preferably with the sea surface temperature (SST) in the east and west Tropical Pacific Ocean (TPO). For PRB with the SST in the central and western regions of the TPO in the interannual (4-8 years) and decadal (8-14 years) scales, the decreases (increases) in streamflow precede the El Nino (La Nina) events. These results indicate multiscale relations between the basins' streamflow and climate phenomena not documented in previous works, relevant to forecast the extreme flow events in the Colombian Pacific rivers and for planning and implementing strategies for the sustainable use of water resources in the basins studied.The first author was supported by the Program for Strengthening Regional Capacities in Research, Technological Development and Innovation in the department of Naritio and the CEIBA foundation for doctoral studies. The second author was supported by the Doctoral Scholarship of the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior Brazil (CAPES) Finance Code 001 and Universidad del Valle (Cali-Colombia). The Conselho Nacional de Desenvolvimento Cientifico e TecnolOgico (CNPq) of Brazil partially supported the fifth and sixth authors under grants 305942/2015-8 and 302322/2017-5, respectively. This research was done partially during an internship of the first two authors at the Research Institute of Water and Environmental Engineering of the Universitat Politecnica de Valencia. This work was also supported by the Spanish Ministry of Science and Innovation through Project TETISCHANGE (RTI2018-093717-B-I00). We are thankful to the research groups IREHISA and PSI of the Universidad del Valle. The authors thank the anonymous reviewers for their useful suggestions.Canchala, T.; Cerón, WL.; Francés, F.; Carvajal-Escobar, Y.; Andreoli, RV.; Kayano, MT.; Alfonso-Morales, W.... (2020). Streamflow Variability in Colombian Pacific Basins and Their Teleconnections with Climate Indices. Water. 12(2):1-23. https://doi.org/10.3390/w12020526S12312
Streamflow Intensification Driven by the Atlantic Multidecadal Oscillation (AMO) in the Atrato River Basin, Northwestern Colombia
[EN] The impact of the Atlantic Multidecadal Oscillation (AMO) on the variations in the streamflow in the Atrato River Basin (ARB) during the 1965-2016 period was analyzed here by considering the cold (1965-1994) and warm (1995-2015) phases of this oscillation. The mean streamflow increased after 1994 (AMO phase change). This increase is related to the strengthening of the zonal gradients of the sea surface temperature (SST) and sea level pressure (SLP) between the tropical central Pacific and the tropical Atlantic after 1994 (warm AMO phase). These gradients contributed to strengthen the Walker cell related upward movement over northern and northwestern South America, in particular during November-December (ND). Consistently, the frequency (R20 mm) and intensity (SDII) of extreme daily rainfall events increased during the 1995-2015 period. Our results show a connection between the AMO and the increase in the streamflow in the ARB during the last five decades. These results contribute to the studies of resilience and climate adaptation in the region.The first author was supported by the Doctoral Scholarship of the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior-Brazil (CAPES), Finance Code 001 and Universidad del Valle (Cali-Colombia). The Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) of Brazil partially supported the second and third authors under grants 302322/2017-5 and 305942/2015-8, respectively. The fourth author was supported by the CAPES-Brazil and Universidade Federal de Vicosa for doctoral studies. The fifth author was supported by the Program for Strengthening Regional Capacities in Research, Technological Development and Innovation in the department of Narino and the CEIBA Foundation for doctoral studies. The seventh author was supported by the CAPES-Brazil. This research was done partially during an internship of the first and fifth author at the Research Institute of Water and Environmental Engineering of the Universitat Politecnica de Valencia. This work was also supported by the Spanish Ministry of Science and Innovation through Project TETISCHANGE (RTI2018-093717-B-I00).Cerón, WL.; Kayano, MT.; Andreoli, RV.; Avila, A.; Canchala, T.; Francés, F.; Rivera, IA.... (2020). Streamflow Intensification Driven by the Atlantic Multidecadal Oscillation (AMO) in the Atrato River Basin, Northwestern Colombia. Water. 12(1):1-23. https://doi.org/10.3390/w12010216S12312