scholarly journals Predicting Stormwater Retention Capacity of Green Roofs: An Experimental Study of the Roles of Climate, Substrate Soil Moisture, and Drainage Layer Properties

2019 ◽  
Vol 11 (24) ◽  
pp. 6956 ◽  
Author(s):  
Antonia Longobardi ◽  
Roberta D’Ambrosio ◽  
Mirka Mobilia
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Green Roofs ◽  
Primary Role ◽  
Rainfall Runoff ◽  
Drainage Layer ◽  
Retention Coefficient ◽  
Wide Range ◽  
Runoff Events

Due to the ever-increasing degree of urbanization, blue and green infrastructures are becoming important tools for achieving stormwater management sustainability in urban areas. Concerning green roofs, although scientists have investigated their behaviors under different climates and building practices, their hydrological performance is still a thought-provoking field of research. An event scale analysis based on thirty-five rainfall–runoff events recorded at a new set of experimental green roofs located in Southern Italy has been performed with the aim of identifying the relative roles of climate, substrate moisture conditions, and building practices on retention properties. The retention coefficient showed a wide range of variability, which could not be captured by neither simple nor multiple linear regression analysis, relating the latter to rainfall characteristics and substrate soil water content. Significant improvements in the prediction of the retention coefficient were obtained by a preliminary identification of groups of rainfall–runoff events, based on substrate soil water content thresholds. Within each group, a primary role is played by rainfall. At the experimental site, building practices, particularly those concerning the drainage layer properties, appeared to affect the retention properties only for specific event types.

scholarly journals A New Method for Sensing Soil Water Content in Green Roofs Using Plant Microbial Fuel Cells

Sensors ◽  
2017 ◽  
Vol 18 (2) ◽  
pp. 71 ◽  
Author(s):  
Natalia Tapia ◽  
Claudia Rojas ◽  
Carlos Bonilla ◽  
Ignacio Vargas
Keyword(s):  
Fuel Cells ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Microbial Fuel Cells ◽  
Green Roofs ◽  
New Method

scholarly journals Watertable fluctuation-induced variability in the water retention curve: Sand column experiments

2020 ◽  
Author(s):  
Zhaoyang Luo ◽  
Jun Kong ◽  
Zhiling Ji ◽  
Chengji Shen ◽  
Chunhui Lu ◽  
...  
Keyword(s):  
Water Content ◽  
Capillary Pressure ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Retention ◽  
Water Retention Curve ◽  
Water Flow Velocity ◽  
Retention Curve ◽  
Wide Range ◽  
Static Conditions

<p>The soil water retention curve (WRC), describing the relation between the soil water content and its corresponding capillary pressure, relies not only on whether drying or wetting occurs but also on the pore scale water flow velocity. Here, we investigated the effects of the watertable fluctuations on the WRC through 28 laboratory experiments covering a wide range of fluctuation amplitudes and periods. Results show that both the response of the capillary pressure and soil water content lag behind the watertable fluctuation, and the vertical capillary pressure distribution in the unsaturated zone is non-hydrostatic, especially for the fluctuations with shorter period. As a consequence of watertable fluctuation, the measured WRC deviates from that under static conditions, depending on both the fluctuation amplitude and period. Moreover, the air-entry pressure under dynamic conditions is considerably larger than that under static conditions, and it first increases and then decreases as the fluctuation period decreases. The effects of the watertable fluctuations on the dynamic capillary coefficient was further examined. It is found that the relation between the dynamic capillary coefficient and saturation is nonunique even for the drying and wetting of a given sand and watertable fluctuation, suggesting a hysteretic dynamic capillary coefficient, and the dynamic capillary coefficient is rate-dependent, decreasing with an increase of fluctuation rate.</p>

scholarly journals Carbonyl sulfide (OCS) exchange between soils and the atmosphere affected by soil moisture and compensation points

2018 ◽  
Author(s):  
Rüdiger Bunk ◽  
Zhigang Yi ◽  
Thomas Behrendt ◽  
Dianming Wu ◽  
Meinrat Otto Andreae ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Forest Soils ◽  
Agricultural Soil ◽  
Carbonyl Sulfide ◽  
Soil Samples ◽  
Potential Contribution ◽  
Wide Range

Abstract. Carbonyl sulfide (OCS) is a chemically quite stable gas in the troposphere (lifetime ~ 2–6 years) and consequently some of it is transported up to the stratosphere where it contributes to the stratospheric sulfate layer. Due to the similarities in uptake mechanism between OCS and CO2, the use of OCS as a proxy for CO2 in ecosystem gross primary production (GPP) has been proposed. For this application a good understanding of uptake (UOCS) and production (POCS) processes of OCS in an ecosystem is required. A new OCS quantum cascade laser coupled with an automated soil chamber system enabled us to measure the soil-atmosphere OCS exchange of four different soil samples with high precision. The adjustment of the chamber air to different OCS mixing ratios (50, 500, and 1000 ppt) allowed us to separate production and consumption processes and to estimate compensation points (CPs) for the OCS exchange. At an atmospheric mixing ratio of 1000 ppt, the maximum UOCS was of the order of 22 to 110 pmol g−1 h−1 for needle forest soil samples and of the order of 3 to 5 pmol g−1 h−1 for an agricultural mineral soil, both measured at moderate soil moisture. Uptake processes (UOCS) were dominant at all soil moistures for the forest soils, while POCS exceeded UOCS at higher soil moistures for the agricultural soil, resulting in net emission. Hence, our results indicate that in (spruce) forests UOCS might be the dominant process, while in agricultural soils POCS at higher soil moisture and UOCS under moderate soil moisture seem to dominate the OCS exchange. The OCS compensation points (CPs) were highly dependent on soil water content and extended over a wide range of 130 ppt to 1600 ppt for the forest soils and 450 ppt to 5500 ppt for the agricultural soil. The strong dependency between soil water content and the compensation point value must be taken into account for all further analyses. The lowest CPs were found at about 20 % water filled pore space (WFPSlab), implying the maximum of UOCS under these soil moisture conditions and excluding OCS emission under such conditions. We discuss our results in view of other studies about compensation points and the potential contribution of microbial groups.

Soil nitrogen availability predictor (SNAP): a simple model for predicting mineralisation of nitrogen in forest soils

Soil Research ◽  
2002 ◽  
Vol 40 (6) ◽  
pp. 1011 ◽  
Author(s):  
K. I. Paul ◽  
P. J. Polglase ◽  
A. M. O'Connell ◽  
J. C. Carlyle ◽  
P. J. Smethurst ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Forest Soils ◽  
N Mineralisation ◽  
Area Index ◽  
Basal Rate ◽  
Laboratory Incubation ◽  
Wide Range

A new empirical model (SNAP) combines a simple laboratory measurement of the basal rate of N mineralisation with the modifying effects of daily temperature and water content to predict seasonal and annual rates of mineralisation of forest soils. Short-term (20-60-day) aerobic incubations of either undisturbed or bulked and mixed soil were found suitable for prediction of the basal rate of N mineralisation. Data from laboratory incubations of a range of soils were used to calibrate empirical relationships describing the effects of temperature (Tm) and water (Wm) on rates of N mineralisation. Submodels for predicting daily average temperature (STUF) and water content (SWUF) for up to 3 surface soil layers were developed and used to provide inputs to the Tm and Wm functions, respectively. Inputs required for SNAP are restricted to variables whose values are easily obtained. In addition to the amount of N mineralised during a short aerobic laboratory incubation, other soil properties required are bulk density, gravel and clay content, and upper and lower limits of soil water content. Climatic data required included daily air temperature, rainfall, and solar radiation. Other inputs are slope, leaf area index of the stand, and approximate mass and height of litter. Predicted rates of N mineralisation have been verified using data from 9 native forests, 12 radiata pine plantations, and 12 eucalypt plantations from across southern Australia. Despite the wide range of forest types, soil types, climatic regions, and management systems, predicted annual rates of N mineralisation were in close agreement with those observed in the field, regardless of whether daily soil temperature and water content were predicted (R2 = 0.76, P < 0.001, n�=�127) or observed (R2 = 0.78, P < 0.001, n = 68). Sensitivity analysis showed that it was most important to minimise analytical error in inputs used to calculate the basal rate of N mineralisation (i.e. soil temperature, water content, and N mineralised during laboratory incubation). The model was more sensitive to daily soil temperature than to daily soil water content.

SOIL WATER CONTENT AFFECTS THE AVAILABILITY OF PHOSPHATE

1985 ◽  
pp. 185-189
Author(s):  
M.C.H.Mouat Pieter Nes
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Solution ◽  
Equivalent Reduction

Reduction in water content of a soil increased the concentration of ammonium and nitrate in solution, but had no effect on the concentration of phosphate. The corresponding reduction in the quantity of phosphate in solution caused an equivalent reduction in the response of ryegrass to applied phosphate. Keywords: soil solution, soil water content, phosphate, ryegrass, nutrition.

Effect of inter-row cultivation on soil carbon dioxide emission in a peach plantation

2010 ◽  
Vol 59 (1) ◽  
pp. 157-164 ◽  
Author(s):  
E. Tóth ◽  
Cs. Farkas
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Carbon Dioxide Emission ◽  
Nutrient Content ◽  
Soil Disturbance ◽  
Biological Properties ◽  
Soil Tillage ◽  
Favourable Effect ◽  
Volumetric Soil Water Content

Soil biological properties and CO2emission were compared in undisturbed grass and regularly disked rows of a peach plantation. Higher nutrient content and biological activity were found in the undisturbed, grass-covered rows. Significantly higher CO2fluxes were measured in this treatment at almost all the measurement times, in all the soil water content ranges, except the one in which the volumetric soil water content was higher than 45%. The obtained results indicated that in addition to the favourable effect of soil tillage on soil aeration, regular soil disturbance reduces soil microbial activity and soil CO2emission.

Evaluation of a Multi-Rod Probe Performance for Accurate Measurements of Soil Water Content

2020 ◽  
Author(s):  
Justyna Szerement ◽  
Aleksandra Woszczyk ◽  
Agnieszka Szyplowska ◽  
Marcin Kafarski ◽  
Arkadiusz Lewandowski ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content
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