Erosion Risk Research Articles

Identifying Soil Erosion Risks for Planning of Watershed Management: The Case of Weyib Watershed, Southeast Ethiopia

Identifying Soil Erosion Risks for Planning of Watershed Management: The Case of Weyib Watershed, Southeast Ethiopia

A GIS-based modified PAP/RAC model and Caesium-137 approach for water erosion assessment in the Raouz catchment, Morocco

Water erosion poses a significant environmental threat in the Mediterranean region, with pronounced impacts observed throughout Morocco. It impairs soil quality and disrupts both sediment transport and water availability. Contributing factors range from natural (climate, topography, and geology) to anthropogenic (land use, vegetation cover, and management). This study introduces an improved Priority Actions Program/Regional Activity Centre (PAP/RAC) model, enriched with GIS and the Caesium-137 (137Cs) technique, to investigate erosion within Morocco's Raouz basin. Enhanced with additional variables including soil types, slope length, rainfall erosion potential, slope orientation, soil moisture, and land surface temperature, the model transcends the classical approach, promoting granularity and precision in predictions. In addition to the comprehensive model, the 137Cs method, which discerns long-term soil erosion and redistribution, provides a dual-faceted validation, bolstering the robustness of this project's erosion risk evaluation. This study's outcomes underscore the gravity of the erosion hazard with significant soil depletion rates ranging from 8.1 to 20 t ha−1 yr−1, demonstrating the model's alignment with empirical data, affirming its utility. The modified PAP/RAC model concurs with the 137Cs data, demonstrating its usefulness for water erosion assessment and management in similar areas.

Characteristics and dynamic mechanism of rill erosion driven by extreme rainfall on karst plateau slopes, SW China

Driven by climate change and increased human activities, the frequency and intensity of extreme rainfall events are increasing, leading to increased risk of water erosion on slopes in karst rocky desertification (KRD) areas. However, the driving factors (rainfall intensity, slope gradient, and the degree of underground fissure pore), characteristics, and dynamic mechanisms of rill erosion on KRD slopes under extreme rainfall have received limited attention. A rainfall simulation experiment was performed to investigate the driving factors of rill erosion on KRD slopes under extreme rainfall events. The experiments were conducted using an erosion flume (4 m long, 1.5 m wide and 0.35 m deep) with five rainfall intensities (50, 105, 115, 125 and 145 mm·h−1), three-level slope gradients (5°, 15° and 25°), and three typical degrees of underground pore fissure (1 %, 3 % and 5 %). The results showed that extreme rainfall significantly stimulated the formation and development of rill erosion on KRD slopes. In particular, rainfall intensity and slope gradient significantly affected rill erosion (p < 0.05), whereas the degree of underground pore fissure did not have any distinct effect. Increasing rainfall intensity intensified rill erosion by significantly (p < 0.05) promoting the rill density, total rill surface area, and longest of rill length. With increasing slope gradient, the rill density, rill distribution density, and average rill depth significantly increased (p < 0.05). Moreover, extreme rainfall events exacerbated surface soil erosion by enhancing the hydrodynamic characteristics of slope runoff. Rill erosion was most sensitive to the shear stress of runoff, and rill density was found to be the most suitable rill index for describing surface soil erosion on the slope under extreme rainfall. The findings provide valuable insights into the characteristics and mechanisms of soil erosion in karst regions under future climate warming.

Erosion risk analysis in a changing climate

Erosion risk analysis in a changing climate

Impact of forest landscape restoration in combating soil erosion in the Lake Abaya catchment, Southern Ethiopia

As an effect of forest degradation, soil erosion is among Ethiopia’s most pressing environmental challenges and a major threat to food security where it could potentially compromise the ecosystem functions and services. As the effects of soil erosion intensify, the landscape’s capacity to support ecosystem functions and services is compromised. Exploring the ecological implications of soil erosion is crucial. This study investigated the soil loss and land degradation in the Lake Abaya catchment to explore forest landscape restoration (FLR) implementation as a possible countermeasure to the effects. The study used a geographic information system (GIS)-based approach of the Revised Universal Soil Loss Equation (RUSLE) to determine the potential annual soil loss and develop an erosion risk map. Results show that 13% of the catchment, which accounts for approximately 110,000 ha, is under high erosion risk of exceeding the average annual tolerable soil loss of 10 t/ha/year. Allocation of land on steep slopes to crop production is the major reason for the calculated high erosion risk in the catchment. A scenario-based analysis was implemented following the slope-based land-use allocation proposal indicated in the Rural Land Use Proclamation 456/2005 of Ethiopia. The scenario analysis resulted in a reversal erosion effect whereby an estimated 3000 t/ha/year of soil loss in the catchment. Thus, FLR activities hold great potential for minimizing soil loss and contributing to supporting functioning and providing ecosystem services. Tree-based agroforestry systems are among the key FLR measures championed in highly degraded landscapes in Ethiopia. This study helps policymakers and FLR implementors identify erosion risk areas for future FLR activities. Thereby, it contributes to achieving the country’s restoration commitment.

Numerical erosion prediction of aluminum induced by cavitating jet using an Eulerian–Lagrangian method

Cavitation-induced erosion in pump machinery is a significant issue that leads to material loss and increased operating costs. This study develops a numerical method based on an energy balance approach to address the risk of cavitation erosion. Compared with other published methods, three improvements are made. Firstly, it assumes that the local instantaneous pressure is the driving force behind cavity collapse, rather than the far-away ambient pressure field. Secondly, it counts erosion only at the moment that the released shock wave is strong enough to cause surface damage. Thirdly, an Eulerian–Lagrangian method is introduced to simulate multiscale cavitation, in which the volume of fluid (VOF) method and a discrete bubble model (DBM) are combined to reproduce resolvable water-vapor interfaces and unresolvable discrete bubbles, respectively. The developed numerical modeling framework is validated by predicting the erosion of pure aluminum surface caused by a cavitating jet, and it is shown that the simulated erosion region fits well against the experimental results. Additionally, appropriate model coefficients of the erosion prediction method are introduced to achieve quantitative prediction of material mass loss, and the detailed erosion behavior is discussed.

Comparative study of different cavitation erosion assessment methods in cavitating flow around a Delft Twist hydrofoil

Cavitation erosion is a common phenomenon in hydraulic machines, which severely threatens their stable operation. Although several methods for erosion risk assessment have been proposed, few researchers work on the comparative study of different cavitation erosion assessment methods. Therefore, this study utilized Large Eddy Simulation (LES) combined with Zwart-Gerber-Belamri (ZGB) cavitation model to conduct the numerical simulation for the cavitating flow around a Delft Twist hydrofoil. The Erosive Power Method (EPM), Improved Gray Level Method (IGLM) and Energy Conservative Method (ECM) are employed separately to evaluate the cavitation erosion. Among the three results, the EPM results cannot accurately predict erosion in the middle region and trailing edge region, where the U-shaped vortex collapse. The results of IGLM and ECM can predict the erosion in the middle region and erosion caused by the U-shaped vortex at the trailing edge. IGLM still needs artificial thresholds, while ECM emphasizes areas with higher cavitation risk by amplifying parameter n. The ECM method is more objective from the simulation results.

Numerical prediction of cavitation nuisance on hydrofoils: Combined analysis of cavity dynamics and the aggressiveness of collapsing cavitating structures

The unsteady cavitating flow past a three-dimensional twisted hydrofoil is numerically investigated by a large eddy simulation to obtain in-depth insight into the bubble dynamics near the cavitation erosion region. Macroscopic cavity evolution is captured by a multiphase flow computing frame, while the bubble oscillations in the cavitating flow are computed by solving the Gilmore bubble dynamic model, in which the driving force for the bubble movement is exported through the application of a discrete phase model. The cavitation erosion potential is then computed by a robust indicator developed based on the energy balance hypothesis. The relevance between the dynamics and the destructive essence of a cavitation bubble and the erosion intensity is thoroughly analyzed. The results show that the unsteadiness involved in the turbulent cloud cavitation is well reproduced, and the main cavitation erosion risk in the middle region of the hydrofoil is also accurately predicted comparing with the painting test results. A localized high-pressure region is identified near the rear part of the attached cavity where the mainstream encounters the primary reentrant jet flows. The peak bubble internal pressure can reach 487 MPa near the middle plane of the hydrofoil, during the stage when the surrounding liquid pressure is continuously increased. The bubbles with the smallest radius, ranging from 23.1 to 26.3 μm after compressing from their initial sizes (R0 = 100–700 μm) in the near wall region, are associated with the extremely high internal pressure, and they are responsible for the cavitation erosion damage on the hydrofoil surface.

Does spatial resolution matter in the estimation of average annual soil loss by using RUSLE?-a study of the Urmodi River Watershed (Maharashtra), India.

The study investigates the influence of multispectral satellite data's spatial resolution on land degradation in the Urmodi River Watershed in which Kaas Plateau, a UNESCO World Heritage site, is located. Specifically, the research focuses on soil erosion and its risk zonation. The study employs Landsat 8 (30-m resolution) and Sentinel-2 (10-m resolution) data to assess soil erosion risk. The Revised Universal Soil Loss Equation (RUSLE) is used to quantify the average annual soil erosion output denoted by (A), by using its factors such as rainfall (R), soil erodibility (K), slope-length (LS), cover management (C), and support practices (P). R-factor was computed from MERRA-2 rainfalldata, K-factor was derived from field soil sample-based analysis, LS factor was from Cartosat Digital Elevation Model-based data. The C factor was derived from NDVI of Landsat 8 and Sentinel-2, and the P factor was prepared from LULC derived from Landsat 8, and Sentinel-2 was incorporated in the final integration. The soil erosion hazard map ranged from slight to extremely severe. Remote sensing (RS)-based parameters like Land Use Land Cover (LULC) are derived from the Landsat 8 and Sentine-2 satellite data and used to compute the difference in the final outcome of the integration. The study found similarities in average annual soil loss (A) in plain areas, but differences in final soil erosion risk zone (A) were influenced by LULC map variations due to different cell sizes, P factor, and slope gradient. Notable differences were observed in soil erosion risk categories, particularly in high to very severe zones, with a cumulative difference of 73.85 km2. In addition to this, a scatterplot between the final outputs was computed and found the moderate (R2 = 42.08%) correlation between Landsat 8 and Sentinel-2 imagery-based final average annual soil erosion (A) of RUSLE. The study area encompasses various landforms ranging from the plateau to pediplain, and in such situation, the water-led soil erosion categories vary depending on terrain condition along with its biophysical factors and, hence, need to analyze the need of such factors on the average annual soil erosion quantification. Different spatial resolution has an effect on the final output, and hence, there is a need to track this change at various spatial resolutions. This analysis highlights the significant impact of spatial resolution on land degradation assessment, providing precise identification of surface features and enhancing soil erosion risk zoning accuracy.

Impacts of sustainable management on the spatial distributions of erosion susceptibility and probable sediment yield in a mixed-forested watershed

Forest management practices play multifaceted roles in enhancing the geophysical properties that affect raindrop erosion in the watershed, and consequently, sediment deposition in the reservoir. The current work attempts to integrate empirical and physically-based modeling approaches to quantify the impacts of forest conservation on erosion risk and potential sediment accumulation in the mixed-forested Ogouchi Dam watershed in Japan. The reliability of the empirical model for estimating the total erodibility coefficient (TEr), as a function of various forest properties, was evaluated by applying the mathematical expression to multiple forest conditions and comparing the values to field-measured soil erosion rates. The spatial distribution of the empirically derived values showed that about 25.8% of the Government-managed forests and 45.1% of the private forests have higher risks of raindrop splash erosion compared to natural forests. The TEr value in each small Government-divided forest land (less than 5 ha) was then corresponded to the MUSLE management practice factor (MUSLE P) input in each hydrologic response unit (HRU) in the Soil and Water Assessment Tool (SWAT) model to create a sediment yield distribution map and to predict the amounts of sediment accumulation for different management scenarios. The spatial distribution of sediment yield for the base condition showed that 20.9% of the Government-managed forests and 61.6% of the private forests have higher probable amounts of sediment yield relative to the value simulated in the natural forest. A maximum cumulative sediment reduction of about 14.4% is likely attainable upon the complete control of the Government in the entire planted forest area. Overall, this study effectively utilized the field survey datasets to develop a robust empirical model for quantifying erosion risk and was able to couple the results to a GIS-based model that predicts the amounts of sediment yield under varying environmental conditions.

Effects of Water-to-Air Mass Ratio on Long-Term Washing Efficiency and Erosion Risk in an Axial Compressor Under Online Washing Conditions

Abstract One of the main reasons for gas turbines’ performance losses is the deposition of dirt on the compressor blades. Dirt deposit has to be periodically removed to keep the engine performance as high as possible. This is the reason motivating the presence of online water washing systems in most compressor gas turbines. Such systems aim at cleaning the compressor blades to recover efficiency; thus, the larger the water flow, the better it is assumed the compressor is cleaned (fixing all the other conditions). In the present work, we simulate the long-term behavior of a real axial compressor, from the inlet to the first-stage rotor, subject to online water washing with different water flowrates. The frozen rotor approach is adopted to solve the flow field in the rotor region. Simulations are performed by using the unsteady k-ɛ realizable model coupled with a Lagrangian tracking of the injected liquid phase. Water droplet erosion is handled by using a semi-empirical model developed by the authors. In each simulation, 504,000 parcels have been tracked, providing statistically reliable predictions. To simulate the long-term evolution of the washing process, a discrete mesh morphing technique coupled with the use of specific scale factors is adopted. Each of the tested configurations is composed of three successive erosive steps up to the blade compressor end-of-life. By varying the water-to-air mass fraction (WAMF*), six different injection configurations are assessed in terms of long-time average washing efficiency and erosion risk. The results predicted show the dependence of the considered washing indices on water mass flowrate and set the stage for the development of a washing optimization tool, which can help the design and management processes. In scenarios where washing indices are given minimal importance and the objective is to reduce the risk of erosion, the optimal injection configuration was shown to correspond to a WAMF* value of 0.250. Conversely, when washing efficiency is prioritized, the optimal injection configuration has been shown to correspond to the case where WAMF* = 0.750.

Enhancing Riverbank Protection along the Jamuna River, Bangladesh: Review of Previous Countermeasures and Morphological Assessment through Groyne-Based Solutions Using Numerical Modeling

This study investigated riverbank protection strategies along the dynamic Jamuna River in Bangladesh, a braided river prone to erosion and sedimentation. It reviews past countermeasures and emphasizes the effectiveness of groyne-type structures in redirecting flow and preventing erosion. Notably, the left bank exhibited greater stability than the right bank, emphasizing the need for effective groyne installations. A systematic methodology utilizing numerical modeling using International River Interface Cooperation (iRIC Nays2DH) ensured accuracy in assessing morphological impacts. This research presents novel countermeasures incorporating groyne installations along the right bank of the Jamuna River. Simulations are undertaken to assess the effectiveness of these measures under a range of flood scenarios, identifying a zone highly prone to erosion that exhibits the utmost vulnerability. The simulation scenarios comprised a base condition without groynes, two series of groynes separately placed in two selected zones, and a combined approach for both areas. Analysis of the four simulation cases, each encompassing three flood conditions, revealed that implementing two ‘I’-shaped perpendicular groynes in series within the erosion-prone area effectively diverted oblique flow. This approach proved optimal, mitigating erosion risk by redirecting flow and shaping sandbars along the Jamuna River’s riverbank. This study enhances Jamuna River protection, emphasizing groyne-type structures’ importance and promoting a holistic understanding of morphological dynamics for future river management and effective countermeasures.

High organic carbon content constricts the potential for stable organic carbon accrual in mineral agricultural soils in Finland

Sequestering carbon into agricultural soils is considered as a means of mitigating climate change. We used agronomic soil test results representing c. 95% of the farmed land area in Finland to estimate the potential of the uppermost 15 cm soil layer of mineral agricultural soils to sequester organic carbon (OC) and to contribute to the mitigation of climate change. The estimation of the maximum capacity of mineral matter to protect OC in stable mineral-associated form was based on the theory that clay and fine-sized (fines = clay + silt) particles have a limited capacity to protect OC. In addition, we used the clay/OC and fines/OC ratios to identify areas with a risk of erosion and reduced productivity, thus indicating priority areas potentially benefitting from the increased soil OC contents. We found that 32–40% of the mineral agricultural soils in Finland have the potential to further accumulate mineral-associated OC (MOC), while in the majority of soils, the current OC stock in the uppermost 15 cm exceeded the capacity of mineral matter to protect OC. The nationwide soil OC sequestration potential of the uppermost 15 cm in mineral agricultural soils ranged between 5 and 10 Tg, which corresponds to less than the annual greenhouse gas emissions in Finland. The fields with the highest potential for SOC accrual were found in the southern and southwestern parts of the country, including some of the most intensively cultivated high-clay soils. Although the nationwide potential for additional OC sequestration was estimated to be relatively small, the current OC storage in Finnish arable mineral soils (0-15 cm) is large, 128 Tg. Farming practices enabling maximum OC input into the soil play an important role as a tool for mitigating the loss of carbon from high-OC soils in the changing climate. Furthermore, especially in high-clay areas with potential for MOC accrual, efforts to increase soil OC could help improve soil structural stability and therefore reduce erosion and the loss of nutrients to the aquatic environments.

Multi-scenario analysis in the Apulia shoreline: A multi-tiers analytical framework for the combined evaluation and management of coastal erosion and water quality risks

Ongoing climate change is causing threats to coastal areas, according to scenarios of Intergovernmental Panel on Climate Change (IPCC). The coastal areas are becoming highly exposed to erosion as a direct consequence of natural and anthropogenic processes that occur at different spatial-temporal scales. Against this interplay, coastal managers are calling for integrated tools supporting a multi-scenario evaluation of risks arising from natural and anthropogenic stress. A multi-tier analytical framework, exploiting the openly available Earth Observation databases, was developed, allowing the combination of remote sensing, GIS and Bayesian Network to evaluate the probability and uncertainty of coastal erosion risks and connected water quality variation, against ‘what-if’ scenarios, representing different management measures (i.e., Nature-Based Solution) and climate change impacts (e.g., higher incident waves due to increased storminess). Based on the available data for the Municipality of Ugento (Italy), the designed framework was applied over the 2009–2018 timeframe, allowing to capture local-scale shoreline erosion dynamics and driving forces. Results from scenario analysis revealed, to a minor extent, a nexus between oceanographic drivers, shoreline evolution, and water quality changes, with increasing probability of high erosion/accretion and higher turbidity under the simulated rising maximum significant wave height. However, the implementation of Nature-Based Solutions (i.e., circular approach exploiting beached Posidonia oceanica leaves) resulted in significant positive effects, stabilizing the shoreline by reducing high erosion and accretion rates. Despite data constraints, outcomes of the performed assessment could represent valuable information to drive adaptive policy pathways in the context of coastal management along the Ugento shoreline.

Analysis of Factors Influencing Spatial Distribution of Soil Erosion under Diverse Subwatershed Based on Geospatial Perspective: A Case Study at Citarum Watershed, West Java, Indonesia.

The application of remote sensing data has been significant in modeling soil erosion. However, previous studies have fallen short in elucidating and lacked an understanding of the multifactor influencing erosion. This study addresses these limitations by employing the InVEST and the Geodetector models. Specifically, it aims (1) to delineate both spatial and temporal variations in soil erosion within the Citarum watershed from 2010 to 2020, (2) to identify the key drivers of soil erosion and unravel the underlying mechanisms, and (3) to identify the high-risk zones for soil erosion. Both models consider a range of natural predictors, including topography (slope factor), climate (precipitation factor), and vegetation cover (vegetation factor). In addition, they incorporate social parameters such as income per capita and population density, which interact with the watershed's position in the downstream, middle, and upper streams. The results reveal that, over a decade, the average soil erosion increased by 15.50 × 106 tons, marking a 16.65% surge. The impact of factors varies significantly across different subwatershed areas. For example, fraction vegetation cover interactions influence upper- and middle-stream regions, while the downstream area is notably affected by precipitation interactions. The high-risk erosion areas in the watershed are primarily influenced by slope, precipitation, and fractional vegetation cover. In these areas, factors causing high erosion risks include slope, precipitation, and other environmental variables categorized into strata. The study highlights the varying influential factors in different watershed areas.

Integrated Use of GIS and USLE Models for LULC Change Analysis and Soil Erosion Risk Assessment in the Hulan River Basin, Northeastern China

The Hulan River Basin is located in the black soil region of northeast China. This region is an important food-producing area and the susceptibility of black soil to erosion increases the risk of soil erosion, which is a serious environmental problem that affects agricultural productivity, water supply, and other important aspects of the region. In this paper, the changes in LULC (land use and land cover) in the basin between 2001 and 2020 were thoroughly analysed using GIS (geographic information system) and USLE (universal soil loss equation) models. The soil erosion risk in the Hulan River Basin between 2001 and 2020 was also studied and soil erosion hot spots were identified to target those that remained significant even under the implementation of soil conservation measures. Precipitation data were used to obtain the R factor distribution, LULC classification was adopted to assess the C factor distribution, soil data were employed to estimate the K factor distribution, DEM (Digital Elevation Model) data were used to generate an LS factor map, and slope and LULC data were considered to produce a P factor distribution map. These factors were based on the model parameters of the USLE. The findings of LULC change analysis over the last 20 years indicated that, while there have been nonobvious changes, agricultural land has continued to occupy the bulk of the area in the Hulan River Basin. The increase in areas used for human activities was the most notable trend. In 2001, the model-predicted soil erosion rate varied between 0 and 120 t/ha/yr, with an average of 4.63 t/ha/yr. By 2020, the estimated soil erosion rate varied between 0 and 193 t/ha/yr, with an average of 7.34 t/ha/yr. The Hulan River Basin was classified into five soil erosion risk categories. Most categories encompassed extremely low-risk levels and, over the past 20 years, the northeastern hilly regions of the basin have experienced the highest concentration of risk change areas. The northeastern hilly and mountainous regions comprised the risk change area and the regions that are most susceptible to erosion exhibited a high concentration of human production activities. In fact, the combined use of GIS and USLE modelling yielded erosion risk areas for mapping risk classes; these results could further assist local governments in improving soil conservation efforts.

Experimental study of seepage in levee with transverse structure and water barrier

A quasi-real-scale experiment was conducted to understand seepage in levees with internal transverse structures. The experiment involved fabricating levees with transverse structures in the same location and using the same method as that in sand levee experiments previously conducted to examine the feasibility of the optical-fiber-distributed temperature system. Levees with internal structures are susceptible to internal erosion and piping risks, which necessitates the installation of water barriers to mitigate these issues. However, conventional concrete water barriers require curing time, leading to potential secondary damage from flooding during construction. As a countermeasure, a compounded polypropylene (PP) water barrier was developed, which is easy to construct and cost-effective. The performances of both concrete and compounded PP water barriers were verified and compared. Water pressure changes inside the levees were tracked, and to monitor temperature changes inside the levees and gain a deeper understanding of seepage, distributed optical fiber cables were employed. The experimental results revealed that levees with transverse structures had a higher risk of internal erosion and piping due to seepage compared to those without such structures, and such levees require continuous monitoring. Furthermore, internal temperature measurements demonstrated the effectiveness of water barriers in mitigating seepage and backward erosion piping.

Talking ‘bout a revolution: resilience and coastal policy in England

ABSTRACT Sea defence policy in England has proven contentious in the early twenty-first century, with government willing to defend the coast only where it is considered cost effective and not minded to compensate people for any resulting abandonment of homes. Additional focus is brought to this position by the 2015 United Nations Sustainable Development Goals (SDGs) which reflect a growing emphasis on climate change effects and other environmental hazards, and the wellbeing of the current generation and those to come. This requires policy makers to seek to balance economic, social and environmental dimensions, and to tackle inequalities; with a central commitment of the goals to “leave no one behind”. Subsequent to publication of the SDGs, England was promised a revolution in the government’s approach to Flood and Coastal Erosion Risk Management (FCERM). This paper seeks to understand the nature of this revolution with particular regard to extant issues around just governance. It finds that policy fails to deal with issues over the local acceptability of proposals for change and the bearing of risk, and instead lies principally in the elevation of the problematic concept of resilience and an accompanying ambivalence towards ideas of sustainability and sustainable development. International agreement that compensation should be paid to those countries suffering the worst effects of climate change, including sea level rise, suggests that adoption of a similar approach to vulnerable homeowners might be the more appropriate revolution and bring policy more into line with the aspirations of the SDGs.

A multi-institutional update on surgical outcomes after penile silicone sleeve implantation.

The increasing popularity of the silicone sleeve penile implant has been accompanied by concerns over potential risks and adverse events. To provide multi-institutional data on safety outcomes in patients undergoing silicone sleeve penile implant surgery across high-volume implant surgeons. In addition, we discuss preventative techniques to minimize postoperative complications and the management of these events. We performed a retrospective analysis of men undergoing penile silicone sleeve implants between November 2020 and November 2022 with four surgeons, each from a separate institution. Perioperative and postoperative adverse events, including unsatisfactory cosmetic outcomes requiring revision, were determined by physician follow-up. Flaccid penile length and girth were measured preoperatively and postoperatively. A total of 299 male patients underwent silicone sleeve implant surgery, with an average age of 42.5 ± 10.5 years and an average body mass index of 28.5 ± 4.0. The patient cohort exhibited minimal comorbidities, with 5% having hyperlipidemia, 2% being smokers, 2% having cardiovascular disease, and 1% having diabetes. Patients experienced an average increase of 4.1 ± 1.5 cm in their flaccid penile length (a 50% increase) and an average increase of 3.4 ± 1.5 cm in their flaccid girth (a 37% increase) (p < 0.01). Complication rates included new-onset postoperative erectile dysfunction (0%), infection (1.3%), seroma (2.0%), and erosion (5.0%). The average follow-up time was 11.6 months. Notably, our rates of infection and seroma were lower than those reported in a previous single-center review, while erosion rates were higher. This is the largest study to characterize the safety of the penile silicone sleeve implant across multiple institutions. In men who desire cosmetic size augmentation, silicone sleeve implant surgery is associated with significantly increased flaccid penile length and girth. Complications are mainly cosmetic and may be corrected; however, patients should be appropriately counseled on the risk of erosion, which appears to be higher than previously reported.

Modelling topographic influences on vegetation vigour in the Cradle Nature Reserve, Gauteng province, South Africa

The study explores topography and vegetation changes in the Cradle Nature Reserve’s landscape, which is characterised by interconnected water infiltration and drainage patterns with geological features such as sinkholes, using indices such as the Enhanced Vegetation Index (EVI), the Topographic Position Index (TPI), the Topographic Ruggedness Index (TRI), and the Topographic Wetness Index (TWI). The high-resolution satellite images, including Sentinal-2A, the Shuttle Radar Topography Mission Digital Elevation Model, and NASSA Power Rainfall, Temperature, and Ground Wetness in the Root Zone-Modern Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2), were analysed using advanced statistical models. The software tools Stata/SE v.13.1, QGIS v.3.36, and ArcGIS desktop v. 10.8.2 were utilised for this analysis. The results emphasise the significance of incorporating topography into ecological research and highlight the necessity of focused conservation initiatives to address habitat suitability and erosion risk in challenging landscapes. Specifically, the results show that the Enhanced Vegetation Index (EVI) has a strong negative correlation with the Topographic Position Index (TPI) (R2 = 0.95), indicating that TPI usually decreases as EVI increases. This relationship is influenced by landscape features such as sinkholes and depressions, which impact plant health. Additionally, the strong positive relationship between EVI and percentage slope gradient (R2 = 0.85) offers valuable insights for environmental studies and land management practices. Additionally, TRI shows a negative correlation with EVI (R2 = 0.94), emphasising the impact of terrain ruggedness on vegetation density. TWI analysis strongly correlates with slope gradients (R2 = 0.96), highlighting topography’s role in hydrological dynamics. Despite these insights, we acknowledge limitations such as scale dependency and the inability to capture fine terrain details. Integrating topographic information into ecological assessments and land management strategies is crucial for promoting conservation, sustainable practices, landscape ecology understanding, and biodiversity preservation decision-making.