Search results for "basi"
showing 10 items of 12854 documents
Human Impact Effects on Târnava River Basin Aquatic Biodiversity (Transylvania, Romania)
2020
Today the following categories of human impact are present in the Tarnava Watershed: hydrotechnical works, insufficiently treated/cleaned sewage, river substratum mineral exploitation/over-exploitation, manure leakage, artificial standing water, industry, river embankment, deforestation, pouching, etc., the first three of these inducing the highest impact on the lotic systems habitats and biodiversity.
Deep structural setting of the North American-Caribbean plate boundary in eastern Guatemala
2009
Se presenta un modelo bidimensional de gravedad para determinar la estructura en profundidad del sistema de fallas lateral-izquierda de Motagua-Polochic, que son parte del límite de las placas América del Norte y del Caribe. Estos elementos tectónicos, sismicamente activos, atraviesan oeste-este la región de Guatemala y se sobreponen a una línea de sutura donde afloran cuerpos ophiolíticos. En las principales zonas de desplazamiento de las fallas se han desarrollado cuencas de pull-apart y regiones de restricción (push-up). El análisis estructural de algunas de estas fallas, situadas a lo largo del valle Izabal y del valle Motagua, en combinación con los datos obtenidos del satélite, ha per…
Cohort-Dependent Sex Ratio Biases in the American Crocodiles (Crocodylus acutus)of the Tempisque Basin
2015
A male-biased sex ratio of 3:1 has been reported for a population of American crocodiles (Crocodylus acutus) in the Tempisque River Basin, Guanacaste, Costa Rica. If confirmed, this would constitute one of the largest male-biased sex ratios reported for any population of a member of the genus Crocodylus. Here, we examine the aforementioned population of C. acutus and report on sex ratios of hatchling, juvenile, and adult age classes within a sample of 474 crocodiles captured in the Tempisque Basin between May 2012 and June 2014. Hatchling sex ratio is exceptionally male biased (3.5:1), an imbalance that is maintained in juveniles but is reduced in adults (1.5:1). Mark–recapture data documen…
A Soil Water Assessment Tool (SWAT) Modeling Approach to Prioritize Soil Conservation Management in River Basin Critical Areas Coupled With Future Cl…
2021
About 44% of the Indian landmass experiences the adverse impact of land degradation. This loss of sediments caused by soil erosion reduces the water quality of local water bodies and decreases agricultural land productivity. Therefore, decision-makers must formulate policies and management practices for sustainable management of basins that are cost-effective and environment friendly. Application of the best management practices (BMPs) to properly manage river basins is difficult and time-consuming. Its implication under various climate change scenarios makes it more complicated but necessary to achieve sustainable development. In this study, the soil and water assessment tool (SWAT) model…
U-Pb dating of middle Eocene-middle Pleistocene multiple tectonic pulses in the Alpine foreland
2021
Foreland fold-and-thrust belts record long-lived tectonic-sedimentary activity, from passive margin sedimentation, flexuring, and further involvement into wedge accretion ahead of an advancing orogen. Therefore, dating fault activity is fundamental for plate movement reconstruction, resource exploration, or earthquake hazard assessment. Here, we report U-Pb ages of syntectonic calcite mineralizations from four thrusts and three tear faults sampled, at the regional scale, across the Jura fold-and-thrust belt in the northwestern Alpine foreland (eastern France). Four regional tectonic phases are recognized in the middle Eocene-middle Pleistocene interval: (1) pre-orogenic faulting at 44.7&thi…
Results of the DEKORP 1 (BELCORP-DEKORP) deep seismic reflection studies in the western part of the Rhenish Massif
1991
Summary Within the DEKORP project (DEKORP: Deutsches Kontinentales Reflexionsseismisches Programm) a joint deep seismic reflection venture with the BELCORP (Belgian Continental Reflection Seismic Programme) group of the Belgian Geological Survey was carried out in 1987 across the Rhenish Massif, a part of the mid-European Variscides. This orogenic belt developed in the Upper Devonian/Carboniferous. Mostly Devonian rocks crop out at the surface. The Rhenish Massif is bordered by two sedimentary troughs: the sub-Variscan Foredeep in the north and the Permo-Carboniferous Saar-Nahe Basin in the south. In the east-west direction it is subdivided by the axial depression of the Eifel Nord-Sud Zone…
Geoarchaeological investigations of a prominent quay wall in ancient Corcyra: Implications for harbour development, palaeoenvironmental changes and t…
2018
Abstract In antiquity, the harbour-city of Corcyra (modern: Corfu) was a prevailing naval power in the Mediterranean and had several harbours to host a considerable fleet. Today, these harbours are totally or partly silted and concealed under modern urban infrastructure. Comprehensive geoarchaeological studies were conducted on the northeastern fringe of the Analipsis Peninsula where excavations have revealed the archaeological remains of a massive quay wall (Pierri and Arion sites). These remains are located east of known ancient harbour structures that belong to the Alkinoos Harbour. Our study aimed to reconstruct the palaeoenvironmental setting of the harbour facilities at the Pierri sit…
Modeling of wind gap formation and development of sedimentary basins during fold growth: application to the Zagros Fold Belt, Iran
2016
Mountain building and landscape evolution are controlled by interactions between river dynamics and tectonic forces. Such interactions have been extensively studied, however a quantitative evaluation of tectonic/geomorphic feedbacks, which is imperative for understanding sediments routing within orogens and fold-and-thrust belts, remains to be undertaken. Here, we employ numerical simulations to assess the conditions of uplift and river incision necessary to deflect an antecedent drainage network during the growth of one, or several, folds. We propose that a partitioning of the river network into internal (endorheic) and longitudinal drainage arises as a result of lithological differences w…
Strong intracontinental lithospheric deformation in South China: Implications from seismic observations and geodynamic modeling
2014
Abstract Classical plate tectonics theory predicts concentrated deformation at plate boundaries and weak deformation within plates. Yet, the existence of intracontinental orogens shows that highly deformed regions can occur within continental plates, which is geodynamically incompletely understood. Shear wave splitting measurements in South China show belt-parallel (i.e. NE–SW) fast directions beneath the Wulingshan-Xuefengshan Belts, while no dominant fast direction is found in the cratonic Sichuan Basin. Tomographic studies in the mantle in the same area show that the thickness of lithosphere beneath the intracontinental orogen is larger than that beneath the cratonic Sichuan Basin. In or…
Morphological characterization of calanchi (badland) hillslope connectivity
2017
Calanchi, a type of Italian badlands created by a combination of water erosion processes and local geomorphological and tectonic controls, is a striking example of long-term landscape evolution. In small temporal/spatial scales, the calanchi exhibit many of the geomorphic processes and landforms that may be observed in fluvial landscapes, hence they may be considered as micro-basins where geomorphic dynamics and landscape features can be related. The goal of this research is testing the use of simple morphometric variables for assessing sediment connectivity of calanchi landforms. In order to detect the morphological characteristics controlling the landscape connectivity of calanchi basins,…