Soil Permeability Research Articles

Correlational of soil permeability and infiltration rate at the ITERA infiltration drainage development plan

Physical development has an impact on the availability of groundwater. The limited water surface requires humans to manage available wisely. Institut Teknologi Sumatera (ITERA) is a state campus on the Island of Sumatera and has an area of 275ha. The eco-drain concept attempted to recover groundwater at all masterplan development. This study aims to reveal how much influence infiltration rate has on soil permeability in the ITERA Infiltration Drainage Development Plan. This research used quantitative research using a correlational approach by processing primary data and further analyzing it in the soil mechanics laboratory at the 8 points of the equal research location. Infiltration rate data was obtained using a double-ring infiltrometer and analyzed with the Horton Method, then the sampling at a depth of ±50 cm analysis with the Falling Head Method. Based on the result, there is no correlation between both tests and resulted in different soil types. The infiltration rate test result of the soil type is loamy sand – sandy loam with moderately – moderately slow infiltration classification. The soil permeability type is fine sand or silty clay with medium and low permeability, and the infiltration rate only affected 37.6% of the permeability soil result.

Geological, geophysical, and geotechnical approaches on the slip surface investigation on Cisumdawu Highway, West Java, Indonesia

This study used geological, geophysical, and geotechnical methods to investigate the causes of landslides in a newly established Cileunyi Sumedang Dawuan (Cisumdawu) Highway, Sumedang Regency, West Java Province. A combination of geological field observation, subsurface geoelectric resistivity-based survey, and borehole drilling were applied to obtain the subsurface data of a research area. A total of 10 boreholes were drilled to collect geoengineering data, including the soil material and N-SPT value for validation purposes. The soil hardness and resistivity were measured and compared to establish the relationship between resistivity and engineering properties. The result revealed that percolating water zone in the permeable loose soil was located above the impermeable layer, estimated as a slip surface. The analysed subsurface measurement and borehole data showed that the depth of the slip surface is between 26-27m. The study is important to determine the mitigation steps for the highway slope stability construction.

Effect of seasonal freeze–thaw process on spatial and temporal distribution of soil water and its infiltration to recharge groundwater

AbstractClarifying the distribution and dynamics of soil moisture during the freeze–thaw process is crucial for surface ecology and is an objective requirement to investigate the mechanism of changes during the groundwater recharge process in a freeze–thaw zone. Based on the monitoring data of soil moisture and temperature in the Changbai Mountain area, the freeze–thaw process is classified into four periods. This study investigates the hydrothermal migration processes during different periods. The simultaneous heat and water model is used to simulate and analyse the infiltration of soil moisture into groundwater under five precipitation insurance rates. The results are as follows: (1) The smaller the soil depth, the stronger is the correlation between soil temperature and air temperature during the freeze–thaw process. (2) The redistribution of soil moisture before and after freeze–thaw is significantly affected by the soil texture, and soil permeability affects the recharge of soil moisture from the upper region to the lower region during the thawing period. (3) Groundwater receives vertical infiltration recharge mainly during non‐freezing and is supplied by freezing and snowmelt recharge during the stable thawing period. The percentage of soil water infiltration during the stable thawing period in the total annual infiltration increases gradually with the precipitation insurance rate.

Influence of matrix materials on the stability of weakly layered rock slopes

In this study, a novel matrix material was developed by blending powdery clay (PC) with varying proportions of diatomaceous earth (DE) and straw, aiming to enhance the mechanical stability and ability of the water cycle of the materials. The unconsolidated-undrained triaxial, compaction, and infiltration tests were conducted to assess the mechanical characteristics of PC containing different ratios of DE and straw. The findings revealed that the addition of straw and DE enhanced soil permeability, as their quantities increased. However, when both DE and straw were mixed with the matrix soil at similar content levels, a decrease in the permeability coefficient was observed. Additionally, the results indicated a decrease in maximum compacted density with an increase in the proportions of straw and DE. When the straw content was below 50% and the DE content was below 40%, a rapid decrease in density was observed. In contrast, when the straw content exceeded 50% and the DE content exceeded 40%, the rate of density reduction decreased. Considering water cycle and mechanical stability comprehensively, the optimal soil matrix ratios are recommended as 50% PC, 40% DE content, and 10% straw. At this ratio, the cohesion specimen reaches its maximum value at approximately 42.83 kPa. Therefore, the appropriate selection of matrix materials in slope projects can enhance drainage performance, shearing strength, and slope stability, effectively reducing the likelihood of slope disasters.

Insights Into Estimation of Sand Permeability: From Empirical Relations to Microstructure-based Methods

Abstract This study evaluates various methods for estimating soil permeability using microtomography-derived data and compares them to the conventional laboratory approaches. Different methods, including measurement in custom-designed permeameter at micro-CT-compatible scale, empirical equations, simulated sifting, semi-theoretical equations, pore-network modeling, and lattice-Boltzmann simulations, were applied to samples of sandy soils with distinct microstructural properties. The empirical equations showed varied results, highly dependent on the method chosen. The simulated sifting method was able to adequately estimate the granulometric properties of the soil, allowing the use of empirical permeability formulations for substantially small samples. Semi-theoretical equations based on the microstructural properties presented reasonable agreement for some samples. The pore-network modeling approach demonstrated computational efficiency but lacked accuracy. The lattice-Boltzmann method required significant computational resources but did not provide substantially closer alignment with the measured hydraulic properties of some samples. None of the simulations was able to properly determine the permeability of silty and organically contaminated sand. The study highlights the complexity of permeability estimation, emphasizing the need for choosing volumes of interest, resolution of micro-CT scans, and methods that match specific soil characteristics and available computational resources.

Seasonal and decadal subsurface thaw dynamics of an Aufeis feature investigated through numerical simulations

AbstractAufeis (also known as icings) are large sheet‐like masses of layered ice that form in river channels in arctic environments in the winter as groundwater discharges to the land surface and subsequently freezes. Aufeis are important sources of water for Arctic river ecosystems, bolstering late summer river discharge and providing habitat for caribou escaping insect harassment. The aim of this research is to use numerical simulations to evaluate a conceptual model of subsurface hydrogeothermal conditions that can lead to the formation of aufeis. We used a conceptual model based on geophysical data from the Kuparuk aufeis field on the North Slope of Alaska to develop a two‐dimensional heterogeneous vertical profile model of groundwater flow, heat transport, and freeze/thaw dynamics. Modelling results showed that groundwater can flow to the land surface through subvertical high permeability pathways during winter months when the lower permeability soils near the land surface are frozen. The groundwater discharge can freeze on the surface, contributing to aufeis formation throughout the winter. We performed sensitivity analyses on subsurface properties and surface temperature and found that aufeis formation is most sensitive to the volume of unfrozen water available in the subsurface and the rate at which the subsurface water travels to the land surface. Although a trend of warming air temperatures will lead to a greater volume of unfrozen subsurface water, the aufeis volume can be reduced under warming conditions if the period of time for which air temperatures are below freezing is reduced.

Differential Water Conservation Capacity in Broadleaved and Mixed Forest Restoration in Latosol Soil-Eroded Region, Hainan Province, China.

The water conservation capacity of the litter and soil layers of forest ecosystems improves the function of forest ecosystems in conserving soil and water. Plantation restoration plays a key role in preventing soil erosion. In order to evaluate the water conservation capacity of plantation restoration in Latosol soil-eroded region, we analyzed the litter thickness and mass, water absorption process, water holding recovery process, and soil water holding capacity of five restoration types (Hevea brasiliensis, Acacia mangium, Eucalyptus robusta, Acacia-Eucalyptus, and Acacia-Hevea) in the Mahuangling Watershed, Hainan province. The results showed that the thickness of the litter ranged from approximately 3.42 ± 0.24 to 4.73 ± 0.81 cm, and the litter mass ranged from 5.04 ± 1.52 t·ha-1 to 13.16 ± 1.76 t·ha-1, with higher litter mass in the SL layer than in the UL layer. The litter mass of A. mangium was higher than that of H. brasiliensis, E. robusta, Acacia-Eucalyptus, and Acacia-Hevea, which was 3.16 ± 1.76 t·ha-1. A. mangium forest was significantly higher than other plantation restoration types in terms of the maximum water retention capacity (Qmax) and the effective water retention capacity (Qeff). The soil bulk weight ranged from approximately 1.52 ± 0.09 to 1.59 ± 0.08 g·cm-3, and porosity ranged from 31.77 ± 4.72 to 35.62 ± 3.02%, both of which increased with the depth of the soil layer. The water holding capacity of 0-60 cm soil varied from approximately 12.94 ± 7.91 to 45.02 ± 31.79 t·ha-1, with A. mangium having the best soil permeability and the strongest soil water holding capacity. The entropy weight method was used to conduct a comprehensive evaluation, and the results showed that the water conservation capacity of the soil layer was 1.26 times higher than that of the litter layer, in which the water conservation capacity of A. mangium was the strongest, with a comprehensive evaluation value of 0.2854, which effectively intercepted rainfall and reduced surface runoff. Hence, we suggest that the planting of A. mangium should be considered in future ecological restoration projects of the erosion area of Mahuangling in order to improve the function of conserving soil and water in a restoration forest ecosystem.

HUBUNGAN LAJU INFILTRASI TERHADAP PERMEABILITAS TANAH DAN MUKA AIRTANAH DI DAERAH DESA TAJUR KECAMATAN CITEUREUP

Infiltration is an important process in a hydrological system and acts as a medium for air infiltration into the soil. The process of infiltration in soil can be influenced by several factors, namely, rainfall, vegetation, land slope, land use, and soil moisture. Apart from this, other factors such as groundwater level and soil permeability also have an influence on the infiltration process, both of which are related to each other in terms of the rate of infiltration or air infiltration into the soil. If the infiltration process is disrupted, it results in the pooling of air on the ground surface, which affects the hydrological system. It is necessary to know how factors such as groundwater levels and soil permeability influence the infiltration rate. Based on this, the aim of this research is to determine the relationship. between infiltration rate, groundwater level, and soil permeability and their influence. The research method was carried out by taking data from direct groundwater level measurements and infiltration rate measurements, as well as samples for soil permeability analysis. Then an interpretation of the data obtained is carried out and presented in a map of the infiltration zone and soil permeability zone. The research area in Tajur Village has 2 infiltration zones, namely the slow-medium zone and the medium zone with medium and rather fast soil permeability and low-medium groundwater depth.

Efficiency of the Sprinkling Irrigation Method for Irrigation Of Soybean And Cauliflower

In order to reduce the population's need for food and rational use of water resources in the conditions of typical irrigated gray soils Tashkent region, the sprinkling irrigation method was used for soybean crops "Nafis" and cauliflower "Raskot", while taking into account the volumetric mass of the soil, soil porosity, soil permeability. This is explained by the fact that the timing of irrigation, given to crops, irrigation rates, seasonal irrigation rates, the impact on growth, the development and productivity of plants are described

Semi‐analytical solution for double‐layered elliptical cylindrical foundation model improved by prefabricated vertical drains

AbstractThis work proposes a semi‐analytical solution for a double‐layered elliptical cylindrical soft foundation improved by prefabricated vertical drains. The governing equations, continuity conditions are boundary conditions in the elliptical cylindrical system are introduced first. The Laplace transform is employed to convert the time variable t in partial differential equations into the Laplace complex argument s. Based on the boundary condition and continuity condition, the solution in the frequency domain is derived. By using Abate's fixed Euler Algorithm, the solutions in the time domain are obtained. A finite element analysis is performed to demonstrate the accuracy of the proposed solution. Then, parametric studies reveal that soil permeability and soil compressibility have great influences on the second layer of soil in the elliptical cylindrical system, but relatively small effects on the first layer. Neglecting differences in the hydraulic conductivity and the coefficient of volume compressibility of multi‐layered soil in the elliptical cylindrical system could not predict the excess pore pressure in the second layer correctly.

Rainfall Infiltration through Stratified Colluvial Deposits: Analytical Approach vs. Numerical Modelling

This work investigates the rainfall infiltration process within homogeneous and stratified colluvial deposits caused by short (1–3 h) and intense (40–90 mm/h) rainfall, using both analytical and numerical infiltration modelling. The findings of the investigation demonstrate that the classic Green–Ampt model can be employed effectively to study homogeneous colluvial covers with permeability equal to or lower than kw = 10−5 m/s and that are subject to a 1 h rainfall with intensity I ≥ 45–50 mm/h. In these circumstances, a top-down saturation front forms within the colluvial deposit, leading to the saturation of a 70–100 cm-thick layer. This critical condition occurs every 5–10 years in the mountain area of the Friuli Venezia Giulia Region (NE Italy), which corresponds to a lower return period of critical hydrologic events when compared with other mountain basins in the Alps due to the higher initial degree of saturation characterising colluvial covers in this area (70–95%). When analysing stratified colluvial covers, the Dagan–Bresler approximate model, as well as the numerical modelling, emphasised the strong influence that abrupt variations in the permeability of the various soil layers have on the infiltration process at depth. In particular, the presence of a top organic soil horizon that is rich in macro-pores and is characterised by a higher permeability (k = 10−4 m/s) actually reduces the possibility of surficial ponding, which is the basic condition of the “piston” models. The highly permeable top soil allows for a rapid downward infiltration up to contact with the underlying colluvial material, which is less permeable (k = 10−5 m/s). Therefore, a perched water table forms starting from the organic soil–colluvium interface, originating pore–water overpressures within the colluvial deposit, with maximum values in the order of 5–10 kPa.

Characteristics and Mechanism of Cd Release and Transport in Soil Contaminated with PE-Cd

Microplastics （MPs） are a type of emerging contaminants that pose a potential threat to global terrestrial ecosystems. The accumulation of MPs in soil inevitably affects soil physical and chemical properties， both directly and indirectly. Additionally， owing to their small size and surface features， MPs have excellent sorption capacity for both organic and inorganic materials， thus affecting their fate in the environment. However， the influence of MPs on heavy metal sorption and transport in soil is still not fully understood. In this study， polyethylene （PE） and Cd were selected as research objects， and on the basis of clarifying the adsorption mechanism of Cd on PE MPs， the effects of PE concentration and particle size on Cd release and transport behavior in soil under different ionic strengths and types （Ca2+ and Na+） were studied using column leaching experiments. The results of the batch experiments showed that the adsorption capacity of PE MPs for Cd2+ decreased with the increase in particle size. Scanning electron microscopy （SEM）， Fourier transform infrared spectroscopy （FTIR）， and Zeta potential were used to analyze the properties of PE MPs and adsorption behavior of Cd2+ onto MPs. The adsorption was mainly a physical process and was controlled by intra-particle diffusion. The adsorption kinetics could be described well by the quasi-second-order kinetics and Webber-Morris model. The adsorption isotherm conformed to the Langmuir model， indicating monolayer adsorption. The results of leaching experiments showed that the effect of PE MPs on Cd release and transport in soil was related to the CaCl2 concentration. At high ionic strength （0.05 mol·L-1 and 0.1 mol·L-1）， PE promoted the transport of Cd. The effluent concentration of Cd2+ increased from 6.48 mg·L-1 and 16.79 mg·L-1 to 7.12 mg·L-1 and 23.45 mg·L-1， whereas at low ionic strength （0.01 mol·L-1）， Cd transport was inhibited by PE MPs， and the effluent concentration of Cd2+ decreased from 0.66 mg·L-1 to 0.57 mg·L-1. The larger the amount of PE added， the more significant the promoting or inhibiting effect. Additionally， the release and transport of Cd in soil were also affected by the MPs particle size and concentration. When the addition amount was small （1%， 4%）， the large-sized MPs were more conducive to the transport of Cd in soil. When the addition amount was large （7%， 20%）， MPs with small particle sizes promoted Cd2+ transport more significantly. When the leaching solution used was NaCl， soil permeability decreased significantly. PE MPs had no significant effect on Cd release and transport but changed the stability of soil aggregates. In conclusion， PE MPs could change the release and transport behavior of Cd in soil， and the impact results were not only related to the particle size and content of MPs but were also influenced by the chemical properties of the soil solution.

SOIL ERODIBILITY AND ITS EROSION POTENTIAL IN SADAWARNA DAN AND SURROUNDING AREA, CIBOGO DISTRICT, SUBANG REGENCY, WEST JAVA PROVINCE

The Sadawarna Dam and its surroundings, which are located in Subang Regency, are currently under construction. Change in land use caused by the construction occurred. Land management and soil conservation are needed to prevent uncontrolled erosion because it can caused slopes in critical condition, flood occurred in the downstream areas of river, and silting of dam. One of the information in land management and soil conservation is by identifying the soil erodibility which aims to find out the sensitivity of the soil to erosion in the research area. Soil erodibility affected by grain size distribution, soil structure, soil organic matter, and soil permeability. In this research area, the soil erodibility was calculated based on disturbed sample in the field which was then tested in the laboratory. The laboratory tests include sieve analysis, hydrometer analysis, and %c organic. Soil permeability obtained from previous studies. The research area is dominated by clay-sized soil which are the result of weathered claystone in Subang Formation. Soil erodibility value in the research area ranged from 1,100 – 0,448 t ha h/ha MJ cm with dominance of low soil erodibility classes. The dominance of clay-sized soil causes low soil erodibility value because clay sized soil has cohesive properties so it tends to be difficult to erode.

Characteristics of soil physical and chemical properties on Arabica coffee land in Bener Meriah Regency

Bener Meriah Regency is one of the Arabica coffee producing areas in Aceh Province. This Arabica coffee has been cultivating for years by the Gayo people with a continuous cultivation system throughout the year. Continuous cultivation for years causes a decrease in soil fertility in both physical and chemical properties, resulting in a decrease in coffee production. This study aims to determine the physical and chemical characteristics of the soil on Arabica coffee land in Bener Meriah Regency. The study used a quantitative descriptive method through land surveys and analysis of data in the field and analysis of soil samples in the laboratory. Observations were made on 15 Land Units Type (LUT) obtained from the overlay of elevation maps, slope maps, soil type maps and existing coffee plantation maps of Bener Meriah Regency. Parameters observed included soil structure, soil permeability, soil aggregate stability, soil pH, total and available P. The results showed that the soil structure was classified as crumb, soil permeability was slow to fast, soil aggregate stability was classified as unstable to rather stable, soil pH was acid to rather acid, P total was very low to very high, and P available was very low.

Study of Residual Soil Permeability Coefficient Post Addition of Coal Fly Ash

Residual soil is soil that is often used as barrier cover soil at the closure of B3 waste storage facilities. This is because the shear strength of the soil is quite good. The minimum value of the soil permeability coefficient (k) for barrier hoods at the closure of B3 waste storage facilities is 10-7 cm/sec. Many residual soils have a soil permeability coefficient (k) of less than 10-7 cm/sec. Because the dominant compound in coal fly ash is silica, mixing this fly ash with residual soil can reduce the value of the soil permeability coefficient (k) and is also expected to increase the shear strength value of the soil. In this study, residual soil samples were mixed with fly ash at 5%, 10%, 15%, 25% and 35% of the dry weight of the soil. This research aims to determine the effect of adding fly ash on the parameters of dry density, shear strength and soil permeability. The tests carried out were standard proctor testing, direct shear test, and Falling-Head permeability testing. The residual soil used in this research came from Hamlet I, Bintang Meriah Village, Pancur Batu District, Deli Serdang Regency. Based on standard proctor testing, the maximum density (gd max) of original soil is 1,410 gr/cm3. The largest maximum density (gd max) was obtained when adding 15% fly ash, namely 1.471 gr/cm3. In the direct shear test, the original soil cohesion value was 0.024 kg/cm² with an internal shear angle of 37.96º. In the variation of adding 15% fly ash, the cohesion value was 0.131 kg/cm² with an internal friction angle of 53.08º. Based on the Falling-Head permeability test, the original soil permeability coefficient value was 1.98 x 10-6 cm/s. The permeability coefficient value for variations in adding 15% fly ash was obtained at 8.02 x 10-8 cm/s.

A Large-Sized Permeameter for Studying Suffusion Characteristics of Anisotropic Soils

Abstract Seepage-induced suffusion involves the migration of fine particles within a soil matrix. Seepage flow is affected by the soil permeability anisotropy of anisotropic soil fabric; however, suffusion anisotropy is unclear because of the limited function of existing permeameters. In recent studies, the effect of seepage direction has been investigated under only low hydraulic gradients because the control of seepage direction relies merely on gravity. In this study, a new, large-sized permeameter is developed with which suffusion tests can be conducted along horizontal or vertical seepage directions under high hydraulic gradients. Correspondingly, the permeameter can accommodate a specimen of 540 × 500 × 470 or 540 × 540 × 440 mm3 (length × width × height). The seepage direction is switched by changing the boundary conditions of the specimen with detachable perforated plates that allow pressurized water originating from different inlets to flow along horizontal or vertical directions. Two repeated pairs of tests were performed on a gap-graded clayey gravel to investigate the suffusion anisotropy of saturated clayey gravel. The results show that the maximum relative deviations of measurements for initial hydraulic conductivity, initiation, and failure hydraulic gradients are less than 3.5 %, demonstrating satisfactory reliability. The ratio of the initial horizontal hydraulic conductivity to vertical hydraulic conductivity for the test soil is 13.87, indicating a significantly anisotropic fabric induced by compaction. The ratios of horizontal initiation and failure hydraulic gradients to vertical initiation and failure hydraulic gradients are 0.52 and 0.59, respectively. This implies that suffusion anisotropy should not be neglected for evaluating the internal instability of anisotropic soils.

A Step from Vulnerability to Resilience: Restoring the Landscape Water-Storage Capacity of the Great Hungarian Plain—An Assessment and a Proposal

The extreme drought in Europe in 2022 also hit hard the Great Hungarian Plain. In this short overview article, we summarize the natural environmental conditions of the region and the impact of river control works on the water-retention capacity of the landscape. In this respect, we also review the impact of intensive agricultural cultivation on soil structure and on soil moisture in light of the meteorological elements of the 2022 drought. The most important change is that the soil stores much less moisture than in the natural state; therefore, under the meteorological conditions of summer 2022, the evapotranspiration capacity was reduced. As a result, the low humidity in the air layers above the ground is not sufficient to trigger summer showers and thunderstorms associated with weather fronts and local heat convection anymore. Our proposed solution is to restore about one-fifth of the area to the original land types and usage before large-field agriculture. Low-lying areas should be transformed into a mosaic-like landscape with good water supply and evapotranspiration capacity to humidify the lower air layers. Furthermore, the unfavorable soil structure that has resulted from intensive agriculture should also be converted into more permeable soil to enhance infiltration.

The success of Quercus ilex plantations in agricultural fields in eastern Spain

Twenty-five years after planting, we measured the survival, growth and reproduction of 153 Quercus ilex plantations promoted by the afforestation programme of the European Union’s Common Agricultural Policy in agricultural fields in the east of the Iberian Peninsula, as a function of climatic aridity and stand characteristics related to water supply and competition among trees for water. Using field sampling, we found that, on average, 80% of the trees in plantations survived, more than 55% had already produced acorns and the tallest tree in each field exceeded 4 m, which are all higher values than those reported for forest plantations of this species in the same area and which represent the overcoming of the limitations imposed by climatic aridity on the natural regeneration of the species. A small proportion of the variation in all success variables was explained by water-related plantation characteristics, such as planting density, drought intensity in the year after planting, and soil permeability. However, climatic aridity only influenced the proportion of reproductive trees, but not the other variables of plantation success. However, most of the variation in planting success variables was linked to who owned the field, which nursery produced the seedlings, and the year of planting. Our results support the idea that the deep soils of agricultural fields counteract the negative effect of climatic aridity on plant performance, but that it is necessary to standardise nursery and planting practices, adapt planting density to the environmental characteristics of the site and provide irrigation supply in the early years to ensure the success of future plantations.

Modelling the impact land use change on flood risk: Umia (Spain) and Voglajna (Slovenia) case studies

Accurate quantification and assessment flood hazards is critical for mitigation and prevention. This study proposes a methodological framework for analysing this hazard and its relationship to agricultural and forestry land use. The objective is to obtain an integrative methodology based on the HEC-HMS model and to apply different simulations, with land use changes as indicator in two different study areas, taking into account the different characteristics of each basin and the different regulations of each area. This was done in two river basins, the Umia Basin (north-western Spain) and the Voglajna Basin (eastern Slovenia). The hydrological models obtained showed a very high performance in the calibration and validation periods. In the Umia River Basin agricultural use has priority over forestry, with food security taking precedence over water security. Reforestation only upstream has been shown to be almost as beneficial as reforestation throughout the basin. However, the use of abandoned land currently limits the reduction of peak discharge. Nevertheless, for an event designed with a 100-years return period, a reduction of about 12% was achieved. The increase in agricultural use promoted by the administration could increase this peak by about 6%, thus increasing the flood hazard, but it has been shown that this use on less permeable soils and upstream would not significantly increase this peak (<1% for the event studied). On the other hand, the Voglajna Basin has a smaller catchment area and fragmented land use, and a mosaic landscape. For the 100-years return period the reduction in peak discharge is only few percent compared to the baseline scenario even if 30% of the agricultural land (about 7% of the total area) is changed to forest land use. The information provided by the simulations is a useful indicator that can be incorporated into management plans to ensure appropriate decision making by the administration. Not only for the application of nature-based solutions (NBS) and providing evidence-base for the NBS and the reduction of flood risk, but such information is key when the use changes from forestry to agriculture and vice versa, as it provides tools to ensure food and water security. In both case studies it was demonstrated how stakeholders need to undertake optimal and strategic planning and management in order to reduce the risk of flooding. In turn, the use of this modelling, as well as the calculation of scenarios from a perspective that not only evaluates different land use changes, but also incorporates different regulations, is presented as an innovative and realistic analysis.

Predicting the california bearing ratio via hybrid method of multi-layer perceptron

The California Bearing Ratio (CBR) holds significant importance in the design of flexible pavements and airport runways, serving as a critical soil parameter. Moreover, it offers a means to gauge the soil response of subgrades through correlation, an aspect pivotal in soil engineering, particularly in shaping subgrade design for rural road networks. The CBR value of soil is influenced by numerous factors, encompassing variables like maximum dry density (MDD), optimum moisture content (OMC), liquid limit (LL), plastic limit (PL), plasticity index (PI), soil type, and soil permeability. The condition of the soil, whether soaked or unsoaked, also contributes to this value. It is worth noting that determining CBR is time-consuming and extensive. Acknowledging the gravity of this determination, the study introduces a pioneering approach employing machine learning. This innovative technique uses a foundational multi-layer perceptron model, harnessing the algorithm’s robust capabilities in addressing regression challenges. A hybridization approach enhances the multi-layer perceptron’s performance and achieves optimal results. This approach integrates the Bonobo Optimizer (BO), Smell Agent Optimization (SAO), Prairie Dog Optimization (PDO), and Gold Rush Optimizer (GRO). The hybrid models proposed in this study exhibit promising results in predicting CBR values. The MLAO3 hybrid model is particularly noteworthy, emerging as the most accurate predictor among the range of models, with an impressive R2 value of 0.994 and an RMSE value of 2.80.