Hydraulic characterization and hydrological behaviour of a pilot permeable pavement in an urban centre,Brazil

Considering all the alterations on hydrology and water quality that urbanization process brings, permeable pavement (PP) is an alternative to traditional impermeable asphalt and concrete pavement. The goal of the PP and other low impact development devices is to increase infiltration and reduce peak runoff flows. These structures are barely used in Brazil aiming stormwater management, one of the big hydrological issues in cities throughout the country, with increasing urbanization rates. The main objective of this paper is the hydraulic characterization of a PP and the assessment of its hydrological efficiency from the point of view of the infiltration process. The study focuses on a pilot area in a parking lot in an urban area (Recife, Brazil). Soil elements filling the voids between concrete elements were sampled (particle size density, water contents) and tested with water infiltration experiments at several points of the 3 m × 1.5 m surface pilot area. Beerkan Estimation of Soil Transfer parameters algorithm was applied to the infiltration experiment data to obtain the hydraulic characteristics of the soil composing the PP surface layer, the concrete grid pavers (with internal voids filled with natural soil) permeability being neglected. Results show that the soil hydraulic characteristics vary spatially within the pilot area and that the soil samples have different hydraulic behaviours. The hydraulic characteristics derived from Beerkan Estimation of Soil Transfer parameters analysis were implemented into Hydrus code to simulate runoff, infiltration and water balance over a year. The numerical simulation showed the good potential of the PP for rainfall–runoff management, which demonstrates that PP can be used to retrofit existing parking infrastructure and to promote hydrological behaviour close to natural soils. Copyright © 2016 John Wiley & Sons, Ltd.     

Assessing the vulnerability of over-exploited volcanic aquifer systems using multi-parameter analysis,Toluca Basin,Mexico

The potential for contamination of groundwater in an over-exploited system led to this investigation on aspects of aquifer vulnerability in the Toluca Basin, Mexico. This study involved the use of various hydrogeological, geochemical and isotopic tools to better understand the susceptibility to contamination where heavy groundwater extraction along with industrial extensive development is concentrated. Geochemical and isotopic analyses of groundwater from production wells along the mountain boundary show little evidence of contamination at present time. Radiocarbon and tritium data collected in piezometers and wells penetrating the Lower basalt aquifer indicate that the groundwater is of varying age and quality. These data, in addition to stable isotope and chemical data also indicate evidence of contamination in the Lower aquifer; which could be associated with fast recharge in the mountains or injection of waste water by illegal wells. Evidence found in this study of low downward gradients in the valley fill sediments and the presence of low permeability aquitard deposits suggest that the aquifer system is currently not highly threatened by surface sources of contamination. However, where urban and industrial development occurs, in the centre of the valley and along the flanks of the Basin, the vulnerability of the aquifer system increases significantly.     

Buried impact basins,the evolution of planetary surfaces and the Chicxulub multi‐ring crater

Impact craters are distinctive landforms on Moon, Mars, Venus and other bodies of the Solar System. In contrast, the Earth has few craters, due to the dynamic nature of the planet, where craters and other geological structures are destroyed, modified or covered. Planetary missions have also shown that in other worlds where craters are numerous and well preserved, the crater record has been modified, through the identification of buried structures. Studies of the concealed crater record have major implications for the crater‐size frequency distribution and crater‐counting chronologies. On Earth, Chicxulub is an example of a large multi‐ring buried basin. Its study provides clues for the investigation other planetary surfaces. In addition, geophysical surveys have unravelled its deep 3‐D structure, providing data and constraints for new planetary missions.     

New evidence of sea‐level lowstands and paleoenvironment during MIS 6 and 4 in the Cantabrian coastal karst: the Cobiheru cave (North Iberia)

The geomorphological evolution of the Cobiheru Cave shows the influence of the non‐carbonate coastal mountain ranges on coastal karst evolution, as well as the temporal distribution of the cold‐adapted fauna sites in the Cantabrian Coast. Geomorphological observation and uranium/thorium (U/Th) dating lead to the construction of an evolution model. The model comprises two episodes of cave deposition occurring at c. 60–70 and 130–150 ka, linked to cold climate conditions, global sea‐level lowstands and the erosion of alluvial fans that covered the karst. Moreover, the comparison between the Cobiheru record and some raised beaches identified in previous studies sets the beginning of the sea‐level lowering in the Cantabrian Sea during the marine isotope stages (MIS) 5–4 transition. Two palaeoenvironments are inferred based on finding Equus ferus and Elona quimperiana. A wet deciduous forest would have developed on the emerged marine terrace of the Cobiheru Cave since at least the Middle Pleistocene, and an open landscape with scarce vegetation would have been present at c. 65 ka. The erosional event identified in the Cobiheru Cave helps to understand the temporal distribution of cold‐adapted mammals located in the Asturias region. The probable sites of cold‐adapted fauna developed in caves and alluvial fans would have disappeared after 65 ka. Therefore, palaeontological and palaeoclimate research based on cold‐adapted mammals suggests the occurrence of an hiatus in the palaeontological record prior to 50 ka. Copyright © 2017 John Wiley & Sons, Ltd.