Excess Surface Water Research Articles

Hydrogeophysical mapping of paleochannels for water security in Bhawanigarh Block, District Sangrur, Punjab, India

Paleochannels, ancient buried riverbeds, offer significant potential for groundwater management and contribute to achieving the Sustainable Development Goals (SDGs), particularly those focused on clean water (SDG 6) and sustainable ecosystems (SDG 15). These channels, formed when rivers change course due to natural processes or human activities, become filled with loose, permeable sediments like sand and gravel, making them natural reservoirs capable of storing large volumes of groundwater. This characteristic makes paleochannels invaluable for enhancing water security in arid and semi-arid regions.The present study, conducted in the Bhawanigarh block of Sangrur District, Punjab, focuses on mapping paleochannels for Managed Aquifer Recharge (MAR) using Electrical Resistivity Survey techniques. A total of 37 Vertical Electrical Soundings (VES) were performed with a Computerized Resistivity Meter, and the findings were validated using well-logging, exploration data, historical aerial photographs, and satellite imagery. Identifying and mapping these paleochannels enable targeted groundwater recharge efforts, enhancing the sustainable management of water resources.By strategically utilizing paleochannels for artificial recharge, excess surface water can be directed into these hidden reservoirs, effectively replenishing groundwater supplies. This approach supports agricultural and drinking water needs and strengthens resilience against climate change impacts, aligning with SDG 13 (Climate Action). Moreover, the careful management of these ancient channels promotes the sustainable use of natural resources, contributing to the overall goals of environmental sustainability and water security outlined in the SDGs.

Testing the hydrological performance of live pole drains (LPD) for mitigation of slope instability

Nature-based solutions (NbS) and soil bioengineering techniques have gained considerable attention due to their relevant hydrological functions and ability to mitigate slope instability. Live pole drains (LPD), a lesser-known NbS, have traditionally been deployed on slopes to drain the excess surface water and regulate the soil's water budget, making it a suitable technique for stormwater management and landslide prevention. However, neither the LPD performance as a plant-based drainage system nor its potential to regulate the soil-water budget through hydrological processes have been thoroughly studied. This paper presents a novel pilot, lab-based approach for testing the hydrological performance of LPD under different soil hydrological conditions. We built three different treatments and investigated their hydrological performance under multiple storm events. We explored how LPD regulate the soil-water budget by partitioning the water inputs (i.e., rainfall precipitation) into water outputs (i.e., surface runoff, subsurface flow, and percolation). The study revealed that LPD can effectively manage stormwater by draining excess runoff and buffering water in the soil, outperforming fallow soil. Subsurface flow and percolation were significantly higher under LPD treatments when compared to fallow ground, suggesting that the presence of an enhanced structure in the soil results in high soil hydrological performance. The presence of a secondary species with the LPD showed a more efficient hydrological performance than an LPD alone, which aligns with the current implementation of NbS fostering biodiversity. Antecedent soil moisture impacted the hydrological performance of LPD by altering the relative infiltration capacity of the soil and by potentially modifying the availability of channels for preferential flow. Our findings provide a sound basis for future research to improve our understanding of the hydrological performance of LPD for slope instability mitigation and encourage their reproduction and upscaling.

Development and Application of a New Open-Source Integrated Surface–Subsurface Flow Model in Plain Farmland

Accurately characterizing rainfall runoff processes in plain farmland, especially at the plot scale with significant micro-topographic features, has presented challenges. Integrated surface–subsurface flow models with high-precision surface flow modules are appropriate tools, yet open-source versions are rare. To address this gap, we proposed an open-source integrated surface–subsurface flow model called the FullSWOF-Plain model, in which the one-dimensional subsurface module Hydrus-1D was integrated with a modified two-dimensional surface water flow module (FullSWOF-2D) using the sequential head method. Various experimental scenarios were simulated to validate the model’s performance, including two outflow cases (i.e., 1D and 2D) without infiltration, a classical one-dimensional infiltration case, and two typical rainfall events at the experimental field. The results demonstrate the accuracy of this proposed model, with the Nash–Sutcliffe efficiency (NSE) of the simulated discharge exceeding 0.90 in the experimental field case and the root mean squared error (RMSE) values for soil moisture at five depths consistently below 0.03 cm3/cm3. However, we observed a lag in the simulated response time of soil moisture due to the neglect of preferential flow. The micro-topography significantly influenced ponding time and ponding areas. Lower local terrain normally experienced earlier surface ponding. Scattered surface ponding water first occurred in the ditch and followed in the relatively low areas in the main field. The concentration process of surface runoff exhibited hierarchical characteristics, with the drainage ditch contributing the most discharge initially, followed by the connection of scattered puddles in the main field, draining excess surface water to the ditch through rills. This quantitative study sheds light on the impact of micro-topography on surface runoff in plain farmland areas.

Modeling of Soil Water Distribution in a Small Mid-Latitude Watershed on the British Isle for Short Term Landslide and Flood Risk Assessment

The R-TopModel hydrological model coupled with two landslide and flood probability distribution models was applied to simulate the daily hydrological conditions of a small catchment in the Midlands of the British Isles, throughout 2017. Originally, the methodology was applied to a risk area in the tropical region. In this work, the application was extended to mid-latitude watersheds. The hydrographic basin around the Carsington Water dam (located in the Midlands of the Great Britain) is chosen because it presents risks. The model Nash-Sutcliffe Efficiency for the upstream discharge from the Carsington Water dam reached 50% with a correlation coefficient of the order of 70%, an acceptable value considering the seasonal effects of the dam on evapotranspiration and higher soil permeability. Modeling the distribution of soil moisture and excess surface water allowed obtaining the spatial distribution of the maximum conditional probability of landslides and floods in the Carsington Water catchment. These probability maps obtained are consistent with long-term susceptibility maps for Great Britain.

Developing managed aquifer recharge (MAR) to augment irrigation water resources in the sand and gravel (Crag) aquifer of coastal Suffolk, UK

Managed aquifer recharge (MAR) offers a potential innovative solution for addressing groundwater resource issues, enabling excess surface water to be stored underground for later abstraction. Given its favourable hydrogeological properties, the Pliocene sand and gravel (Crag) aquifer in Suffolk, UK, was selected for a demonstration MAR scheme, with the goal of supplying additional summer irrigation water. The recharge source was a 4.6 km drainage channel that discharges to the River Deben estuary. Trialling the scheme in June 2022, 12,262 m3 of source water were recharged to the aquifer over 12 days via a lagoon and an array of 565 m of buried slotted pipes. Groundwater levels were raised by 0.3 m at the centre of the recharge mound with an approximate radius of 250 m, with no detrimental impact on local water features observed. The source water quality remained stable during the trial with a mean chloride concentration (133 mg L−1) below the regulatory requirement (165 mg L−1). The fraction of recharge water mixing with the groundwater ranged from 69% close to the centre and 5% at the boundary of the recharge mound, leading to a reduction in nitrate-N concentration of 23.6 mg L−1 at the centre of the mound. During July–September 2022, 12,301 m3 of recharge water were abstracted from two, 18 m boreholes to supplement surface irrigation reservoirs during drought conditions. However, the hydraulic conductivity of the Crag aquifer (∼10 m day−1) restricted the yield and thereby reduced the economic viability of the scheme. Construction costs for the MAR system were comparatively low but the high costs of data collection and securing regulatory permits brought the overall capital costs to within 18% of an equivalent surface storage reservoir, demonstrating that market-based mechanisms and more streamlined regulatory processes are required to incentivise similar MAR schemes.

Analysis of Farmers’ Respondents on Awareness and Knowledge of Climate Change in Agriculture in Nagaland State India

The impact of climate change can be seen on several crops in various regions and gives considerable insight into the anticipated effects on the food production in the North East India. In India particularly North East is taking on a visible shift due to the impact of climate change. Seasons and rainfall patterns change, rivers run dry and springs water no longer sustains communities whose livelihood depends on the existing water system to provide livestock needs, agriculture and household activities. Unplanned urbanization and economic development, deforestation and unsustainable land use in the mountainous region leads to excess surface water runoff, depletion of topsoil and poor operation and maintenance of water have all contributed to the challenge. An attempt has been made to collect the data from 300 farmers respondents based on Population Proportionate to Size (PPS) technique to assess the awareness and knowledge level about the impact of climate change on agriculture. The results revealed that the majority of the respondents were aware of climate change aspects like ‘terms and meaning of climate change’, ‘increasing temperature year after year’, ‘crop damages’, ‘changes in season pattern’, etc. Regarding the knowledge level of the respondents more than half of the respondents (58.00 percent) had a medium level of knowledge followed by low (24.67 percent) and high (17.33 percent) levels of knowledge about climate change and related issues.

Proposing Optimal Locations for Runoff Harvesting and Water Management Structures in the Hami Qeshan Watershed, Iraq

Iraq, including the investigated watershed, has endured destructive floods and drought due to precipitation variability in recent years. Protecting susceptible areas from flooding and ensuring water supply is essential for maintaining basic human needs, agricultural production, and industry development. Therefore, locating and constructing storage structures is a significant initiative to alleviate flooding and conserve excessive surface water for future growth. This study aims to identify suitable locations for Runoff Harvesting (RH) and dam construction in the Hami Qeshan Watershed (HQW), Slemani Governorate, Iraq. We integrated in situ data, remotely sensed images, and Multi-Criteria Decision Analysis (MCDA) approaches for site selection within the Geographical Information Systems (GIS) environment. A total of ten criteria were employed to generate the RH suitability maps, including topographic position index, lithology, slope, precipitation, soil group, stream width, land cover, elevation, distance to faults, and distance to town/city. The weights of the utilized factors were determined via Weighted Linear Combination (WLC) and Analytic Hierarchy Process (AHP). The resulting RH maps were validated through 16 dam sites preselected by the Ministry of Agriculture and Water Resources (MAWR). Findings showed that the WLC method slightly outperformed AHP regarding efficiency and exhibited a higher overall accuracy. WLC achieved a higher average overall accuracy of 69%; consequently, it was chosen to locate new multipurpose dams for runoff harvesting in the study area. The overall accuracy of the 10 suggested locations in HQW ranged between 66% and 87%. Two of these sites align with the 16 locations MAWR has recommended: sites 2 and 5 in the northwest of HQW. It is noteworthy that all MAWR dam sites were situated in medium to excellent RH zones; however, they mostly sat on ineffective geological localities. It is concluded that a careful selection of the predictive factors and their respective weights is far more critical than the applied methods. This research offers decision-makers a practical and cost-effective tool for screening site suitability in data-scarce rugged terrains.

Water Management to Cope with the Effects of Climate Change Best practices in Water Management at Wageningen University & Research

Wageningen University & Research studies the causes of heavy rainfall and droughts and is looking for solutions to these phenomena [1]. For example, green spaces in the urban environment ensure that water can be drained into the ground. Storage of water is also important, because not only the number of heavy rains is increasing, also there are longer periods of drought. On WUR Campus, these principles of coping with flooding and drought are applied. There is a sizeable area of green space which serves as a groundwater discharge area. The large ponds on campus are used to collect and store excess surface water. During droughts the ponds retain water on campus. In two campus buildings, rain is harvested for flushing toilets and watering inner gardens. The rainwater is harvested from rooftops and stored in underground water tanks. A natural garden was laid out in 1998, and four years ago a natural wetland garden was added to the campus.The effects of climate change, such as droughts and rising sea water levels affect freshwater supplies, which makes efficient use of water increasingly important. WUR aims to reduce consumption of tap water every year, by increasing water use efficiency and switching to sources other than tap water.

Optimizing Managed Aquifer Recharge Locations in California's Central Valley Using an Evolutionary Multi‐Objective Genetic Algorithm Coupled With a Hydrological Simulation Model

AbstractManaged aquifer recharge (MAR) can provide long‐term storage of excess surface water for later use. While decades of research have focused on the physical processes of MAR and identifying suitable MAR locations, very little research has been done on how to consider competing factors and tradeoffs in siting MAR facilities. This study proposes the use of a simulation‐optimization (SO) framework to map out a cost‐effectiveness frontier for MAR by combining an evolutionary algorithm with two objective functions that seek to maximize groundwater storage gains while minimizing MAR cost. We present the theoretical framework along with a real‐world application to California's Central Valley. The result of the SO framework is a Pareto front that allows identifying suitable MAR locations for different levels of groundwater storage gain and associated MAR project costs, so stakeholders can evaluate different choices based on cost, benefits, and tradeoffs of MAR sites. Application of the SO framework to the Central Valley shows groundwater can be recharged from high‐magnitude (95th percentile) flows at a marginal cost of $57 to $110 million per km3. If the 10 percent largest flows are recharged the total groundwater storage gain would double and the marginal costs would drop to between $30 and $50 million per km3. If recharge water is sourced from outside local basins (e.g., the Sacramento‐San Joaquin Delta), groundwater storage gain is approximately 25%–80% greater than can be achieved by recharging local flows, but the total cost is about 10%–15% higher because of additional lift cost.

Nitrogen fate during agricultural managed aquifer recharge: Linking plant response, hydrologic, and geochemical processes

Agricultural managed aquifer recharge (Ag-MAR, on-farm recharge), where farmland is flooded with excess surface water to intentionally recharge groundwater, has received increasing attention by policy makers and researchers in recent years. However, there remain concerns about the potential for Ag-MAR to exacerbate nitrate (NO3−) contamination of groundwater, and additional risks, such as greenhouse gas emissions and crop tolerance to prolonged flooding. Here, we conducted a large-scale, replicated winter groundwater recharge experiment to quantify the effect of Ag-MAR on soil N biogeochemical transformations, potential NO3− leaching to groundwater, soil physico-chemical conditions, and crop yield. The field experiment was conducted in two grapevine vineyards in the Central Valley of California, which were each flooded for 2 weeks and 4 weeks, respectively, with 1.31 and 1.32 m3 m−2 of water. Hydrologic, geochemical, and microbial results indicate that NO3− leaching from the first 1 m of the vadose zone was the dominant N loss pathway during flooding. Based on pore water sample and N2O emission data, denitrification played a lesser role in decreasing NO3− in the root zone but prolonged anoxic conditions resulted in a significant 29 % yield decrease in the 4-week flooded vineyard. The results from this research, combined with data from previous studies, are summarized in a new conceptual model for integrated water-N dynamics under Ag-MAR. The proposed model can be used to determine best Ag-MAR management practices.

Evaluating the effects of vegetation and land management on runoff control using field plots and machine learning models.

Excess surface water after heavy rainfalls leads to soil erosion and flash floods, resulting in human and financial losses. Reducing runoff is an essential management tool to protect water and soil resources. This study aimed to evaluate the effects of vegetation and land management methods on runoff control and to provide a model to predict runoff values. Filed plot data and three machine learning (ML) methods, including artificial neural network (ANN), coactive neuro-fuzzy inference system (CANFIS), and extreme gradient boosting (EGB), were used in a test site in the north of Iran. In this regard, plots with various vegetation and land management treatments including bare soil treatment, rangeland cover treatment, forest litter treatment, rangeland litter treatment, tillage treatment in the direction of slope, tillage treatment perpendicular to the slope, and repetition of treatments under forest canopy were constructed on a hillslope. After each rainfall event, the amount of rainfall and corresponding runoff generated in each plot was recorded. Three ML models (ANN, CANFIS, and EGB) were used to establish relationships between amounts of recorded runoff and its controlling factors (rainfall, antecedent soil moisture (A.M.C), shrub canopy percentage and height, tree canopy percentage and height, soil texture (clay, silt, and sand percent), slope degree, leaf litter percentage of soil, and tillage interval). These data were normalized, randomized, and divided into training and testing subsets. Results showed that the ANN performed better than the other two models in predicting runoff in training (R2 = 0.98; MSE = 0.004) and the test stages (R2 = 0.90; MSE = 0.95). Statistical analysis and sensitivity analysis of inputs factors showed that rainfall, rangeland cover, and A.M.C are the three most important factors controlling runoff generation. The adopted method can be used to predict the effect of different vegetation and land management scenarios on runoff generation in the study area and the areas with similar settings elsewhere.

Study of Evaluation of Kenanga Road Drainage Channels, Karang Anyar Region, Tarakan City

Tarakan City is one of the developing areas in North Kalimantan Province. As an effort to increase development and economic development of Tarakan City. Jalan Kenanga Karang Anyar is a road segment in Tarakan City that is still experiencing inundation due to drainage channels that are unable to accommodate or drain excess surface water. The purpose of this study was to determine the capacity of the Kenanga Karang Anyar road drainage channel, Tarakan City. In this study, the calculation of maximum rainfall data is used, for the calculation of discharge and flow velocity using the Manning formula. Based on the calculation results, it is obtained that the design discharge is 7.436 m3/second with the dimensions of the design channel, the bottom width (B) = 1.68 m, the channel height (H) = 2.30 m with the water height (hair) = 1.45 m. For the existing channel, bottom width (B) = 0.63 m, channel height (H) = 0.45 m with water height (hair) = 0.45 m, when there is a flood, the existing channel is unable to accommodate the existing water discharge.

Multi-objective optimization of aquifer storage and recovery operations under uncertainty via machine learning surrogates

Aquifer storage and recovery (ASR) is an important water management approach to store excess surface water into aquifers for later use. Quantitative evaluation of ASR performance is not a trivial task and yet becomes more exacting when uncertainty analysis is added to the dimensionality of the problem. Inclusion of uncertainty into the framework of scheduling optimal ASR operations also increases the level of complexity. This study integrates a surrogate modeling approach coupled with a mixed integer nonlinear programming (MINLP) algorithm to optimize multi-objective ASR operations. The uncertainties are analyzed based upon a thorough sampling of the parameters space as well as a novel analysis of Pareto fronts and variograms of representative solutions. Knee point of representative Pareto fronts is selected for in-depth analysis. As a solution to the dimensionality of the problem, Artificial Neural Network (ANN) is employed to generate surrogate models for predicting groundwater levels and injectate distribution within the aquifer during ASR operations. The computational complexity in building a large number of ANNs and deriving of numerous Pareto fronts via solving the MINLP problem are overcome by the assistance of parallel computing. The results show that optimal ASR operations are highly influenced by hydraulic conductivity and longitudinal dispersivity. Higher hydraulic conductivity values lead to a higher number of active stress periods during storage and recovery phases, which requires large volume of extraction to recover the dispersed injectate. In contrast, higher ratios of longitudinal dispersivity to hydraulic conductivity adversely impact the injectate recovery efficiency. Through meaningful representation of objective function uncertainty by variograms, it is inferred that injectate recovery efficiency is more sensitive to longitudinal dispersivity than hydraulic conductivity.

Experimental Study of Artificial Recharge of Unconfined Groundwater Aquifer for Elected Sites in Salahaddin, Iraq

The study aims to assess the efficiency and susceptibility of aquifers and geological formations in Salahaddin to store excess surface water in rainy and flood seasons, to be alternatives for surface aquifers and to achieve an increase in groundwater levels. Five sites that represent several hydrological basins have been selected for artificial recharge experiments, in which two types of experiments were conducted. In the first, the water was injected into the recharge well with monitoring the level in the same recharge well. In the second, water was injected into the recharge well and the water level was monitored in a close well to the recharge one. Test infusion experiments have been conducted in some locations, and data of water level drawdown was drawn in against time in the form of hydrographs, by using Excel program with attempting to analyze groundwater behavior and movement within the unsaturated layers of the aquifer. Then, the hydraulic properties have also been calculated in some locations from pumping tests or artificial recharge experiments and drawing the hydrograph curve using (Aquifer win32). The study concluded that all the aquifers, in which the artificial recharge experiments were carried out, were very efficient in their response to injections, with minor variations due to heterogeneity of porous media and the thickness of unsaturated zones, which cause different permeability between layers, and different hydraulic properties of aquifers.

Multidisciplinary investigations of a karst reservoir for managed aquifer recharge applications on the island of Vis (Croatia)

Managed aquifer recharge (MAR) refers to a suite of methods by which excess surface water or non-conventional water is stored underground for subsequent recovery or environmental purposes. MAR solutions have been largely used in unconsolidated aquifers, while their application in karst aquifers is rare. This research presents the first results of a MAR viability study on the island of Vis, a small karstic island in the Adriatic Sea. Favorable geological and hydrogeological conditions enable the formation of karst aquifers, making the island autonomous in terms of water supply. The island’s main aquifer, exploited in the Korita well field, is protected from seawater intrusion by several hydrogeological barriers. However, climate change and high seasonal pressures related to tourism pose a threat to the future availability of freshwater. Multidisciplinary field and laboratory investigations were carried out to detail the geological and hydrogeological setting of the island and its groundwater resource. Field analyses consisted of groundwater monitoring and sampling, geophysical investigations (i.e., electrical resistivity tomography), and structural measurements. Laboratory analyses included measurements of principal cations and anions and tritium activity. Despite low precipitation during the observation period (September 2019 - December 2020), the groundwater resource at the Korita site showed stable trends of physico-chemical parameters with a good storage potential and a long-term reserve. Geophysical investigations evidenced a relatively homogeneous sequence of the rock mass at a larger scale, while structural analyses indicated the occurrence of E-W karstified and open fractures that could represent a preferential flow path in the carbonate aquifer. A MAR solution for the Vis island was proposed combining an infiltration pond scheme with the direct injection of the accumulated waters into the aquifer using available wells. The potential water source could be represented by the runoff collected in an old artificial channel and the associated pond system in Korita.

Water Wettability Coupled with Film Growth on Realistic Cyclopentane Hydrate Surfaces.

Although the wettability of hydrate surfaces and hydrate film growth are key to understanding hydrate agglomeration and pipeline plugging, a quantitative understanding of the coupled behavior between both phenomena is lacking. In situ measurements of wettability coupled with film growth were performed for cyclopentane hydrate surfaces in cyclopentane at atmospheric pressure and temperatures between 1.5-6.8 °C. Results were obtained as a function of annealing (conversion) time and subcooling. Hydrate surface wettability decreased as annealing time increased, while hydrate film growth rate was unaffected by annealing time at any subcooling. The results are interpreted as a manifestation of the hydrate surface porosity, which depends on annealing time and controls water spreading on the hydrate surface. The wettability generally decreased as the subcooling increased because higher subcooling yields rougher hydrate surfaces, making it harder for water to spread. However, this effect is balanced by hydrate growth rates, which increase with subcooling. Also affecting the results, surface heating from heat release (from exothermic crystallization) allows excess surface water to promote spreading. The hydrate film growth rate on water droplets increased with subcooling, as expected from a higher driving force. At any subcooling, the instantaneous hydrate growth rate decreased over time, likely from heat transfer limitations. A new phenomenon was observed, where the angle at the three-phase point increases from the initial contact angle upon hydrate film growth, named the crystallization angle. This is attributed to the water droplet trying to spread while the thin film is weak enough to be redirected. Once the hydrate film grows and forms a "wall" around the droplet, it cannot be moved, and further growth yields a crater on the droplet surface, attributed to water penetrating the hydrate surface pore structures. This fundamental behavior has many flow assurance implications since it affects the interactions between the agglomerating hydrate particles and water droplets.

Influence of agricultural managed aquifer recharge on nitrate transport: The role of soil texture and flooding frequency

AbstractAgricultural managed aquifer recharge (Ag‐MAR) is a concept in which farmland is flooded during the winter using excess surface water to recharge the underlying groundwater. In this study, we show how different recharge practices affect NO3− leaching and mineralization–denitrification processes in different soil systems. Two contrasting soil textures (sand and fine sandy loam) from the Central Valley, California, were repeatedly flooded with 15 cm of water at varying time intervals in field and soil column experiments. Nitrogen species (NO3–, NH4+, total N), total C, dissolved O2, and moisture content were measured throughout the experiments. Results show that when flooding occurs at longer intervals (every 1–2 wk), N mineralization increases, leading to an increase of mobile NO3− in the upper root zone and leaching of significant quantities of NO3− from both soil textures (137.3 ± 6.6% [sand] and 145.7 ± 5.8% [fine sandy loam] of initial residual soil NO3−) during subsequent flooding events. Laboratory mineralization incubations show that long flooding intervals promote mineralization and production of excess NO3− at rates of 0.11–3.93 mg N kg–1 wk–1 (sand) and 0.08–3.41 mg N kg–1 wk–1 (fine sandy loam). Decreasing the flooding frequency to 72 h reduces potential mineralization, decreasing the amount of NO3− leached during flooding events (31.7 ± 3.8% [sand] and 64.7 ± 10.4% [fine sandy loam] of initial residual soil NO3–). The results indicate that implementing recharge as repeated events over a long (multiple‐week) time horizon might increase the total amount of NO3− potentially available for leaching to groundwater.

A model for estimating Ag-MAR flooding duration based on crop tolerance, root depth, and soil texture data

Agricultural Managed Aquifer Recharge (Ag-MAR) is an emerging MAR technique that uses agricultural fields as percolation basins to recharge the underlying aquifers. Ag-MAR can be a beneficial solution for storing excess surface water, however, if not managed properly it can potentially harm the soil and crops planted on the field at the time of recharge, ultimately leading to yield loss. Root zone residence time (RZRT), defined as the duration that the root-zone can remain saturated (or nearly saturated) during Ag-MAR without crop damage, is a key factor in Ag-MAR since extended periods of saturation in the root-zone can damage crops. Here we propose a simple RZRT model for estimating a safe Ag-MAR flooding duration based on hydraulic parameters deduced from soil texture, crop tolerance to saturation, effective root depth, and critical soil water content, which is the point where soil re-aeration occurs during drainage. We tested the model with different hydraulic parameter sets and compared the results to observed data and HYDRUS simulations. Using fitted and unfitted hydraulic parameters the average error of the predicted Ag-MAR flooding duration was less than 5 h, and up to a few days, respectively. Consequently, for crops with low flooding-tolerance, the model should be used with caution, but for more tolerant crops, the model provides reasonable predictions. The model also provides a first approximation of the possible amount of water that can be applied during an Ag-MAR event. Based on the RZRT model, we evaluated the Ag-MAR potential of various crops and effective root depths for each of the USDA soil texture classes. A spreadsheet containing the RZRT model including hydraulic parameters, and crop properties is publicly available and can be used as a learning tool or to estimate Ag-MAR flooding duration for different soils. The proposed model can be easily integrated into Ag-MAR assessment tools.

Efficient Design of Road Drainage Systems

Excess surface water on roadways due to storm events can cause hazardous scenarios for traffic. The design of efficient road and transportation facility drainage systems is a major challenge. Different approaches to limit excess surface water can be found in the drainage design standards of different countries. This document presents a method based on hydraulic numerical simulation and the assessment of grate inlet efficiency using the Iber model. The method is suitable for application to design criteria according to the regulations of different countries. The presented method facilitates sensitivity analyses of the performance of different scupper dispositions through the total control of the hydraulic behavior of each of the grate inlets considered in each scenario. The detailed hydraulic information can be the basis of different solution comparisons to make better decisions and obtain solutions that maximize efficiency.

Development of Single Sized Aggregate Porous Concrete for Sustainable Road in Low Traffic Area

Porous concrete design with selected gradation and the developed method is proven to be able to withstand light traffic loads and pass water so that rainwater can be used optimally and keep the ground surface remains a green open area. Porous Concrete is a special concrete material produced with aggregate, cement and water with high porosity, which is between 15 to 30 %, so that water can be easily to pass. The main function of porous concrete is as a concrete pavement covering the soil surface with the aim that water can easily flow under the concrete layer, and thus the excess surface water will be reabsorbed into the ground, rather than just being wasted into the sea, the method of producing porous concrete has been patented. The mixture creates an open cell structure, allowing rainwater to penetrate the underlying land. It can be used for low-traffic areas. Porous concrete that uses one size aggregate or uniform aggregate has low compressive strength but good permeability. Porous concrete at 28 days age has a compressive strength between 3 to 28 MPa with a porosity of 14 to 31 % and a permeability ranging from 0.25 to 6.1 mm / second.