In this paper, we present and analyze a novel global database of soil infiltration measurements, the Soil Water Infiltration Global (SWIG) database. In total, 5023 infiltration curves were collected across all continents in the SWIG database. These data were either provided and quality checked by the scientists who performed the experiments or they were digitized from published articles. Data from 54 different countries were included in the database with major contributions from Iran, China, and the USA. In addition to its extensive geographical coverage, the collected infiltration curves cover research from 1976 to late 2017. Basic information on measurement location and method, soil properties, and land use was gathered along with the infiltration data, making the database valuable for the development of pedotransfer functions (PTFs) for estimating soil hydraulic properties, for the evaluation of infiltration measurement methods, and for developing and validating infiltration models. Soil textural information (clay, silt, and sand content) is available for 3842 out of 5023 infiltration measurements (∼ 76%) covering nearly all soil USDA textural classes except for the sandy clay and silt classes. Information on land use is available for 76 % of the experimental sites with agricultural land use as the dominant type (∼ 40%). We are convinced that the SWIG database will allow for a better parameterization of the infiltration process in land surface models and for testing infiltration models. All collected data and related soil characteristics are provided online in *.xlsx and *.csv formats for reference, and we add a disclaimer that the database is for public domain use only and can be copied freely by referencing it. Supplementary data are available at https://doi.org/10.1594/PANGAEA.885492 (Rahmati et al., 2018). Data quality assessment is strongly advised prior to any use of this database. Finally, we would like to encourage scientists to extend and update the SWIG database by uploading new data to it.
Basic oxygen furnace (BOF) slag is considered as a potential alternative construction material and is used here on an experimental plot to accurately quantify the risk of pollutant release. Since pollutant release depends on flow, this initially requires characterizing BOF slag hydraulic properties. These were monitored and estimated at plot scale by carrying out water infiltration experiments and inverse numerical modeling. Monitoring the plot showed that the BOF slag studied crusted at the surface as a result of weathering processes. Numerical inversion proved that the crusted material differed from the unaltered slag in terms of water retention and hydraulic conductivity functions. Although all the data pointed to a decrease in saturated hydraulic conductivity with crusting, the trends depended on the infiltration devices used for the capillary length (tension disc vs. Beerkan). Scanning electron microscope (SEM) microanalysis of laboratory weathering cells and lysimeter measurements were monitored in parallel to study the microstructure more precisely and highlighted a reduction of porosity by clogging. On the basis of SEM observations, two conceptual models of pore reduction, based on two different pore clogging hypotheses, were applied to predict hydraulic properties. This step demonstrated that the effect on water retention and hydraulic conductivity strongly depended on the way precipitated phases form and coat grains and could explain the evolution of the transport properties observed. This study contributes to knowledge on the hydraulic properties of BOF slag and their evolution due to carbonation.
6 May 2015 in European Journal of Environmental and Civil Engineering
Green roofs are promising urban management tools from the standpoint of both rainwater management and microclimatology. They are considered as a storm water mitigation technique and may also favour evapotranspiration fluxes, which can be beneficial for urban comfort during summer periods. In France, however, water retention performance of green roofs remains unknown, and published values are often unsuitable. Six experimental roofs, including two thicknesses of growing media, three types of vegetation cover and bare surfaces, were monitored for two years in Nantes and compared to an experimental gravel flat roof. The thickest media combined with the most densely vegetated cover yields the best results in terms of storm water mitigation and actual evapotranspiration. In winter, the rainwater retention performance is clearly dependent on the type of experimental roof vegetation. This kind of experimental set-up is well suited to assisting urban planners design tools for storm water mitigation in buildings.