Application of Biochar on the runoff purification performance of porous asphalt pavement

Biochar is currently applied in many low-impact development measures, such as biofilters and filter strips. However, its application in permeable pavement is limited. Due to the wide range of raw material sources, biochar may also contain nutrients and heavy metals. Whether its leachate will cause contamination during application remains unknown. Based on the static leachate contamination test, this study first evaluated the leachate contamination risks of three types of biochar and porous asphalt mixture (PA) with three biochar fillers. Through the pavement infiltration test, the purification performance of PA with biochar fillers and filter layers was further analysed. The results show that biochar contains nitrogen and phosphorus, and the leaching contamination of coconut shell is the most obvious; when the biochar is applied as a filler in PA, the leaching contamination decreases, while the pollutant purification performance is not obvious; when 3−5 mm rice straw biochar is used as a filter layer, the removal rate of total suspended solids can be 100%, but it is accompanied by more serious nitrogen and phosphorus leaching, and the greater the thickness, the more serious the degree of leaching. Deionized water cleaning can remove the phosphates contained in biochar, but have little effect on nitrogen. Therefore, before the application of biochar, cleaning measures should be taken to minimize its leaching contamination.

Integrated Study of Flash Floods in Wadi Basins Considering Sedimentation and Climate Change: An International Collaboration Project

Recently, Wadi flash floods (WFFs) have happened frequently in arid environments, resulting in great damage the society and the environment. In Oman, severe WFFs have occurred repeatedly within the last 10 years causing a huge impact on human lives and properties. This paper aims at introducing the framework of an international collaboration project between Japan and Oman for WFF management considering sediment dynamics and climate changes. Four research groups were established: climate change (G1), rainfall-runoff modeling (G2), sediment yield and transport (G3), and sedimentation and infiltration processes (G4). Several field investigations were conducted since 2017 until now. The detailed field survey to assess the deposited sediment in a dry reservoir by using sediment bars, and infiltration test, as well as drone survey were addressed. Some of the preliminary results and findings from the field investigation is discussed. The results show there is an adverse impact of sedimentation clogging on the infiltration process at the reservoirs. Based on the historical rainfall data analysis, there is a systematic increasing trend of the annual average precipitation with remarkable cycles over the MENA region and Oman. The knowledge obtained from this project is expected to be valuable to understanding sediment dynamics at Wadi basins.

Karakteristik Infiltrasi dan Potensi Irigasi di Lahan Kering Kecamatan Bayan Kabupaten Lombok Utara

Agricultural development with horticultural crops on dry land is one of the government's efforts to increase dry land productivity so that new paddy fields are created in the Bayan area. Noting that land infiltration capability and its classification are important factors needed in irrigation planning to support the development of horticultural agriculture, so it is necessary to conduct field research on this matter. This study aims to determine the characteristics and classification of land infiltration and determine the trend of irrigation that can be applied. Field infiltration tests were carried out in Anyar and Sukadana villages with 4 test points each. The infiltration rate test in the field was carried out using a double ring infiltrometer and a soil test at the Geotechnical Laboratory, Faculty of Engineering, Unram. Analysis of the data used Horton's formula as a comparison and the results of the analysis were presented in the form of tables and graphs, conclusions were made descriptively. The results showed that the average infiltration rate in Anyar Village was at point 1 = 26.90 cm/hour, point 2 = 14.94 cm/hour, point 3 = 27.33 cm/hour, and point 4 = 8.21 cm/hour with soil including sandy clay. Infiltration rate classification of points 1 and 3 is very fast, point 2 is fast and location 4 is rather fast. For Sukadana Village the infiltration rate was obtained at point 1 = 43.52 cm/hour, point 2 = 36.67 cm/hour, point 3 = 12.86 cm/hour, and point 4 = 10.97 cm/hour, with the condition sandy clay soil. Sukadana's infiltration rate classification points 1 and 2 are very fast and points 3 and 4 are rather fast. Based on the results of the infiltration test, for very fast and fast infiltration, it is potential to apply jet irrigation such as sprinklers or perforations and for rather fast infiltration, drip irrigation can be applied with limited drip system

Combining new techniques to investigate water dynamics above a shallow restrictive layer.

<p>Adopting integrated measurement techniques may enhance our understanding of hydropedological processes within the critical zone. To investigate lateral subsurface flow due to lithological discontinuities, a ponding infiltration test, two GPR surveys, and soil penetration resistance (PR) measurements were conducted on a 1 m<sup>2</sup> plot in a vegetated area located in the university campus of Doua (Lyon, France). A GPR grid with 0.2 m intervals was established. In the center of the grid, around the root system of a hawthorn shrub, an infiltration test was conducted using an automated single-ring infiltrometer proposed by Concialdi et al. (2020), to infiltrate a shear-thinning viscous solution (1 g L<sup>−1</sup> Xanthan gum powder). The viscous solution was expected to fill preferential pathways due to the roots, with limited infiltration into the soil matrix, and thus reveal complex geometries or macropore networks in highly heterogeneous soils. To create three-dimensional (3D) representations of the infiltrated solution, two GPR surveys were carried out just before and 20 min after the infiltration test, using a GSSI (Geophysical Survey System Inc., Salem, NH) SIR 3000 system with a 900 MHz antenna. A total of 24 radargrams were collected in time mode by moving the antenna along the survey lines and recording the markers position along the survey line intersections. After the second GPR survey, PR was measured at each of the 36 intersection points of the grid using an electronic hand-pushed cone penetrometer. The cone had a 30° angle and a base area of 1 cm<sup>2</sup>, inserted into the soil at a constant speed of 2 cm s<sup>−1</sup> to a depth of 0.8 m. These measurements were aimed to highlight contrasting penetration resistance characteristics between different soil horizons. We also determined the soil bulk density from 24 undisturbed soil cores (~ 100 cm<sup>3</sup>) collected at different depths from 0 to 50 cm. Finally, an auger was used to extract a 0.69-m-depth soil core for the direct observation of lithological heterogeneities.</p><p>Differenced radargrams from pre- and post-infiltration surveys allowed to detect the 3D infiltration bulb, which was vertically elongated and irregularly shaped, but with an evident horizontal divergence between the depth of 20 and 30 cm. Below 30 cm depth, a significant increasing of soil PR and BD (respectively higher than 2.5 MPa and 1.50 g cm<sup>-3</sup>, between 30 and 50 cm depth) was detected, indicating the presence of a underlying layer, which was also identifiable by visual observation of the soil core. This dense layer impeded water flow. Consequently, the liquid solution partially diverged laterally and accumulated upside this layer, and partially infiltrated into the dense layer along preferential flow paths in correspondence with the plant root system, as detected by the 3D GPR diagram. Summing up and considering every aspect, this study allowed to identify water perching above a shallow restrictive layer for a better understanding of the water dynamics of the investigated soil. This study shows the benefits to couple different types of soil physics approaches to relate hydrological processes to the soil hydraulic and mechanical properties.</p>

Spatialization of physical variables in soils by geophysical, geotechnical and geostatistic methods: the Bayesian maximum entropy data fusion approach

<p>The soil is considered as a biological reactor or an outlet for treated domestic wastewater, respectively to reduce pollutant concentrations in the flows or because the surface hydraulic medium is too remote. In these cases, the saturated hydraulic conductivity of the soil is a key is a quantitative measure to assess whether the necessary infiltration capacity is available. To our knowledge, there is no satisfactory technique for evaluating the saturated hydraulic conductivity Ks of a heterogeneous soil (and its variability) at the scale of a parcel of soil. The aim of this study is to introduce a methodology that associates geophysical measurements and geotechnical in order to better described the near-surface saturated hydraulic conductivity Ks. Here we demonstrate here the interest of using a geostatistical approach, the BME "Bayesian Maximum Entropy", to obtain a 2D spatialization of Ks in heterogeneous soils. This tool opens up prospects for optimizing the sizing infiltration structures that receive treated wastewater. In our case, we have Electrical Resistivity Tomography (ERT) data (dense but with high uncertainty) and infiltration test data (reliable but sparse). The BME approach provides a flexible methodological framework to process these data. The advantage of BME is that it reduces to kriging as its linear limiting cases when only Gaussian data is used, but can also integrate data of other types as might be considered in future works. Here we use hard and Gaussian soft data to rigorously integrate the different data at hand (ERT, and Ks measurement) and their associated uncertainties. Based on statistical analysis, we compared the estimation performances of 3 methods: kriging interpolation of infiltration test data, the transformation of ERT data, and BME data fusion of geotechnical and geophysical data. We evaluated the 3 methods of estimation on simulated datasets and we then do a validation analysis using real field data. We find that BME data fusion of geotechnical and geophysical data provides better estimates of hydraulic conductivity than using geotechnical or geophysical data alone.</p>

Infiltration Capacity of Rain Gardens Using Full-Scale Test Method: Effect of Infiltration System on Groundwater Levels in Bergen, Norway

The rain gardens at Bryggen in Bergen, Western Norway, is designed to collect, retain, and infiltrate surface rainfall runoff water, recharge the groundwater, and replenish soil moisture. The hydraulic infiltration capacity of the Sustainable Drainage System (SuDS), here rain gardens, has been tested with small-scale and full-scale infiltration tests. Results show that infiltration capacity meets the requirement and is more than sufficient for infiltration in a cold climate. The results from small-scale test, 245–404 mm/h, shows lower infiltration rates than the full-scale infiltration test, with 510–1600 mm/h. As predicted, an immediate response of the full-scale infiltration test is shown on the groundwater monitoring in the wells located closest to the infiltration point (<30 m), with a ca. 2 days delayed response in the wells further away (75–100 m). Results show that there is sufficient capacity for a larger drainage area to be connected to the infiltration systems. This study contributes to the understanding of the dynamics of infiltration systems such as how a rain garden interacts with local, urban water cycle, both in the hydrological and hydrogeological aspects. The results from this study show that infiltration systems help to protect and preserve the organic rich cultural layers below, as well as help with testing and evaluating of the efficiency, i.e., SuDS may have multiple functions, not only storm water retention. The functionality is tested with water volumes of 40 m3 (600 L/min for 2 h and 10 min), comparable to a flash flood, which give an evaluation of the infiltration capacity of the system.

A painful unknown: sacroiliac joint diagnosis and treatment

The sacroiliac joint (SIJ) is a complex anatomical structure located near the centre of gravity of the body. Micro-traumatic SIJ disorders are very difficult to diagnose and require a complete clinical and radiological examination. To diagnose micro-trauma SIJ pain it is recommended to have at least three positive provocative specific manoeuvres and then a radiologically controlled infiltration test. Conservative treatment combining physiotherapy and steroid injections is the most common therapy but has a low level of efficiency. SIJ thermolysis is the most efficient non-invasive therapy. SIJ fusion using a percutaneous technique is a solution that has yet to be confirmed on a large cohort of patients resistant to other therapies. Cite this article: EFORT Open Rev 2020;5:691-698. DOI: 10.1302/2058-5241.5.190081

Determination of Sorptivity, Infiltration Rate and Hydraulic Conductivity of Loamy Sand using Tension Infiltrometer and Double-Ring Infiltrometer

This study was conducted to assess the effectiveness and accuracy of tension infiltrometer (TI) over double ring infiltrometer (DI) for determining infiltration rate (I) of loamy sand. Sorptivity (S), infiltration rate and hydraulic conductivity (K) are soil properties that govern the rate of entry of water into the soil and its movement within the soil. The ease and accurate measurement of these properties depend on the instruments used. DI operates by ponding water and could be affected by preferential water flow during infiltration test which could not be avoided especially on a fertile soil. DI and TI at water potentials of -0.02, -0.04, -0.05 and -0.06 m were used to determine infiltration rate of the soil. The mean values of sorptivity for DI and TI at water potentials of -0.02, -0.04, -0.05 and -0.06 m were 847.02, 63.50, 33.15, 29.90 and 19.46 mm/h1/2, respectively. Mean values of infiltration rates for DI and TI at -0.02, -0.04, -0.05 and -0.06 m water potentials were 471.26, 176.84, 73.73, 71.32 and 37.73 mm/h, respectively. Mean values of hydraulic conductivity for DI and TI at -0.02, -0.04, -0.05 and -0.06 m were 344.45, 22.42, 18.61and 16.83 mm/h, respectively. DI required 100-150 litres for the infiltration test, difficult where water is very scarce and gave higher values of infiltration rate. TI saved water (2-3 litres), controlled preferential water flow and values of S, I and K were within the range obtained by other researchers. TI is more effective for measuring hydraulic properties soil than DI.Keywords:Double ring infiltrometer, tension infiltrometer, sorptivity, infiltration rate, hydraulic conductivity

Comparing catchment scale subsurface celerities estimated from recession analysis and infiltration experiments.

&lt;p&gt;Catchment scale hydrological models all have some representation of the dynamics of subsurface flow and hence direct or indirect estimates of the celerities (velocities) involved. Parameters representing these celerities (for example recession coefficients of linear reservoirs) are often calibrated against runoff instead of being estimated directly from measured data. Such a procedure, when applied for hydrological models with (too) many parameters to be calibrated, may lead to unrealistic estimates of subsurface celerity due to equifinality issues. Our aim with this study is to obtain an estimate of the distributions of subsurface celerites corresponding to the distribution of saturation levels through recession analysis. Using the recession characteristic &amp;#923;=log(Q(t)/Q(t+&amp;#8710;t) and looking for sequences of recession in a moving average filtered time series of runoff, we find, for many catchments, no clear structure in the relationship between Q(t) and &amp;#923;.&amp;#160; In order to better understand the recession process we let the runoff be represented by four (parallel) unit hydrographs (UH) of different temporal scales. The UHs thus represent different subsurface celerities through their different temporal scales and different levels of saturation. &amp;#160;Only when there was a systematic build up of saturation from below, i.e. the slowest UH had to be filled to (a chosen max) capacity before the next UH received water, a clear structure between Q(t) and &amp;#923; emerged, where for each value of Q(t) the maximum &amp;#923; represented the true recession to be used for estimating the celerity. &amp;#160;At the tiny Muren catchment (7500 m2) in southern Norway we performed an infiltration test and estimated the saturated hydraulic conductivity to be 0.00045 m/s. The mean celerity estimated from recession analysis for the same catchment was found to be 0.00034 m/s, and when the distribution of celerities from the recession analysis was used in the Distance Distribution Dynamics (DDD) rainfall runoff model a Kling Gupta efficiency criterion of KGE = 0.86 was obtained for runoff simulations at 15 minutes temporal resolution.&lt;/p&gt;

Laboratory-scale assessment of a capillary barrier using fibre optic distributed temperature sensing (FO-DTS)

Recent waste rock pile designs have been proposed to incorporate a fine-grained layer to create a capillary barrier to prevent surface water from draining into the pile interior. This study analyses active fibre optic distributed temperature sensing (FO-DTS) as a tool to measure the effectiveness a capillary barrier system following an infiltration test. A laboratory waste rock column was built with anorthosite waste rock overlain by sand. Volumetric water content is calculated during heat cycles lasting 15 min powered at 15 W/m in the column. A new algorithm is employed to circumvent several requirements for soil specific calibration. The inferred moisture contents were verified by soil moisture probes located adjacent to the cable. The FO-DTS data indicate, at vertical resolutions up to 2 cm, that water is retained in the sand and does not drain into the anorthosite following the infiltration test. The coefficient of determination, R2, between the inferred and measured volumetric water content in the fine cover sand layer is 0.90, while the screened anorthosite maintained an R2 of 0.94 with constant moisture content throughout the test. This study will ultimately help guide future waste rock storage design initiatives incorporating fibre optic sensors, leading to improved environmental mine waste management.