Effects on evaporation rates from different water-permeable pavement designs

Department of Applied Geology, University of Münster, Corrensstrasse 24, 48149 Münster, Germany.
Water Science & Technology (Impact Factor: 1.11). 06/2011; 63(11):2619-27. DOI: 10.2166/wst.2011.168
Source: PubMed


The urban water balance can be attenuated to the natural by water-permeable pavements (WPPs). Furthermore, WPPs have a 16% higher evaporation rate than impermeable pavements, which can lead to a better urban climate. Evaporation rates from pavements are influenced by the pavement surface and by the deeper layers. By a compared evaporation measurement between different WPP designs, the grain size distribution of the sub-base shows no influence on the evaporation rates in a significant way. On the contrary, a sub-base made of a twin-layer decreases the evaporation by 16% compared to a homogeneous sub-base. By a change in the colour of the paving stone, 19% higher evaporation rates could be achieved. A further comparison shows that the transpiration-effect of the grass in grass pavers increases the evaporation rates more than threefold to pervious concrete pavements. These high evapotranspiration rates can not be achieved with a pervious concrete paving stone. In spite of this, the broad field of application of the pervious concrete paving stone increases the importance in regard to the urban climate.

1 Follower
6 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: A new laboratory evaporation measurement device (LEMD) was developed to estimate the evaporation rates of urban surface materials. Here, evaporation is induced by means of a constant heat input and airflow. The evaporation can be measured using two different methods concurrently. Method 1 is based on a balance, which measures the mass loss over time. In method 2 the water vapour transport in the air is measured by humidity sensors thus enabling the calculation of the evaporation rate. Test measurements show a sensitivity of method 2 against influences from the environment, therefore, method 1 was used for subsequent measurements. With the assistance of the LEMD, an estimation of the evaporation rates for different materials was determined within a short period of time and with low costs.First measurements were carried out at 29 different urban surface materials. The main focus was placed on pervious concrete materials. In general, a more evenly distributed evaporation from pervious concrete was observed. It was possible to select pervious materials with anticipated higher evaporation rates for a subsequent field test. Especially two-layered pervious materials with a fine grained top layer and a coarse grained bottom layer show the highest laboratory evaporation rates. Furthermore, very low evaporation rates (even lower as from impervious materials) were observed for pervious materials with coarse grained aggregates. If these results can be verified in the field, it will be possible in future to regulate the urban water balance through the targeted deployment of different types of water-permeable pavements.
    Fuel and Energy Abstracts 12/2011; 46(12). DOI:10.1016/j.buildenv.2011.06.010
  • [Show abstract] [Hide abstract]
    ABSTRACT: Soil water movement is a critical consideration for crop yield in straw-integrated fields. This study used an indoor soil column experiment to determine soil infiltration and evaporation characteristics in three forms of direct straw-integrated soils (straw mulching, straw mixing and straw inter-layering). Straw mulching is covering the land surface with straw. Straw mixing is mixing straw with the top 10 cm surface soil. Then straw inter-layering is placing straw at the 20 cm soil depth. There are generally good correlations among the mulch integration methods at p < 0.05, and with average errors/biases <10%. Straw mixing exhibited the best effect in terms of soil infiltration, followed by straw mulching. Due to over-burden weight-compaction effect, straw inter-layering somehow retarded soil infiltration. In terms of soil water evaporation, straw mulching exhibited the best effect. This was followed by straw mixing and then straw inter-layering. Straw inter-layering could have a long-lasting positive effect on soil evaporation as it limited the evaporative consumption of deep soil water. The responses of the direct straw integration modes to soil infiltration and evaporation could lay the basis for developing efficient water-conservation strategies. This is especially useful for water-scarce agricultural regions such as the arid/semi-arid regions of China.
    Water Science & Technology 05/2012; 65(12):2213-8. DOI:10.2166/wst.2012.140 · 1.11 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Permeable pavement (PP) systems provide opportunities to mitigate the impacts of urbanization on receiving water systems by providing at source treatment and management of stormwater. However, they do not receive mainstream use throughout much of Canada and the USA because of a lack of local guidance documents, demonstration projects and performance data. Studies have repeatedly shown that PPs attenuate stormwater flows by reducing volume and frequency of stormwater flows, reducing and delaying peak flow rates, and increasing flow durations. PP systems have been shown to improve stormwater quality by reducing stormwater temperature, pollutant concentrations and pollutant loadings of suspended solids, heavy metals, polyaromatic hydrocarbons, and some nutrients. This review is intended as a comprehensive summary of the current state of knowledge of the environmental performance of PP systems. Published research is synthesized to examine the hydrologic performance, impacts to water quality, longevity and functionality and maintenance needs of PP systems. Where appropriate, the limitations of current knowledge are discussed and emerging and future research needs are presented. The intent of this review is to provide stakeholders in stormwater management with the critical information that is needed to foster acceptance of PPs as a viable alternative to traditional systems.
    Water Quality Research Journal of Canada 08/2013; 48(3):2013. DOI:10.2166/wqrjc2013.055 · 0.91 Impact Factor
Show more