Search Results (36)

Enzyme-Induced Calcium Carbonate Precipitation (EICP) shows promise for desertification control. This study investigates the effects of solid-to-liquid ratio, calcium sources, Ca²⁺ concentration, temperature, enzyme-to-liquid ratio (ELR), and pH on the activity of soybean crude urease (SCU). Furthermore, the impact of EICP treatment cycles on the mechanical properties, compressive behavior, and wind erosion resistance of aeolian sand (AS) was systematically evaluated, with microstructural evolution and pore characteristics of cemented specimens analyzed through SEM and X-CT. Key findings reveal that SCU activity and the calcium carbonate precipitation rate (PR) reached optimal levels (80~99%) under conditions of a 1:10 solid-to-liquid ratio, 1.0~1.5 M CaCl₂ concentration, 35~70 °C temperature range, and pH 7. After seven EICP treatments, AS specimens exhibited complete cementation with an unconfined compressive strength (UCS) of 580 kPa and a reduced wind erosion rate of 0.151 g/min, effectively mitigating desertification. SEM and X-CT analyses confirmed significant pore infilling and bridging between particles, accompanied by a reduction in pore quantity and permeability coefficient by over two orders of magnitude. EICP demonstrates notable advantages in enhancing mechanical performance, environmental compatibility, and cost efficiency, positioning cemented AS as a viable construction material while offering insights for sand stabilization engineering. These findings provide essential technical support for material innovation, wind and sand disaster prevention, and the sustainable construction of desert highway bases and subbases. Full article

Aeolian sand is susceptible to wind and water erosion, which seriously restricts the ecological restoration and sustainable development in desert areas. Traditional solidification methods have characteristics of high cost, easy pollution, and unstable solidification. Enzyme-induced calcium carbonate precipitation (EICP) is an emerging method that has advantages in terms of cost-effectiveness, environmental friendliness, and durability, and, especially when coupled with fiber reinforcement (FR), it can significantly prevent brittle fracture. In this paper, ultraviolet (UV) erosion and freeze–thaw (FT) erosion tests were conducted to investigate the anti-erosion capacity of aeolian sand solidified by EICP and basalt fiber reinforcement (BFR) or wool fiber reinforcement (WFR). According to the analysis of the variation laws of sample appearance, quality losses, and unconfined compressive strength (UCS) during the UV and FT erosion process, the erosion mechanism was revealed, and the UCS models considering the damage effects were established. The research results indicated that the UCS of aeolian sand solidified by MICP and FR was significantly improved under UV and FT erosion. The strength loss rates of aeolian sand solidified by EICP, EICP–BFR, and EICP–WFR reached 45.4%, 46.6%, and 51.6%, respectively, under 90 h UV erosion. When the FT cycles reached 8, the strength loss rate of aeolian sand solidified by EICP, EICP–BFR, and EICP–WFR attained 41.0%, 49.2%, and 55.8%, respectively. The determination coefficients of the UCS models were all greater than 0.876, indicating that the experimental results were in good agreement with the predicted results, verifying the reliability of the established models. The research results can offer reference values for windproof and sand fixation in desert areas. Full article

Soil loss due to wind erosion and dust deposition has become a growing concern, particularly in arid regions like Al-Baha, Saudi Arabia. The aim of this study was to quantitatively assess soil loss and dust deposition using three different dust collection methods across 20 sites during the summer of 2022. The methods include Big Spring Number Eight (BSNE), which measures airborne dust particles using passive samplers; Surface Dust Collector (SDC), designed to collect dust settling on the ground surface; and Marble Dust Collector (MDCO), which utilizes marble-coated surfaces to trap and measure dust deposition. These methods collectively provide a comprehensive evaluation of dust dynamics in the study area. The objective was to evaluate the effects of wind erosion and dust deposition on soil properties, offering insights into the mechanisms of soil loss in arid environments. The study revealed significant variations in soil characteristics, including low organic matter content (<1%), high calcite (up to 19.62%), and increased salinity levels, with notable quantities of Cl⁻ (211.58 meq kg⁻¹) and Na^⁺ (165.98 meq kg⁻¹). July showed the highest dust deposition (0.0133 ton ha⁻¹), particularly at site S11, while soil loss was lowest at site S5. This research offers novel insights into the nonlinear relationship between soil loss and time, contributing to sustainable soil management strategies. By aligning with Saudi Arabia’s Vision 2030 and the Sustainable Development Goals (SDGs), the findings underscore the need to mitigate soil loss to enhance environmental sustainability, prevent desertification, and promote long-term resilience in arid regions. Full article

Soil fugitive dust (SFD) is a significant contributor to environmental particulate matter (PM), which not only pollutes and affects air quality but also poses risks to human health. The emission inventory can provide a basis for the effective prevention and control of SFD pollution. However, current emission inventories with low resolution and frequency make it difficult to assess dust emissions accurately. Obtaining monthly high-resolution bare soil information is one of the solutions for compiling SFD emission inventories. Taking Daxing District, Beijing, as a case study, this study first extracted bare soil for each month of 2020, 2021, and 2022, respectively, using high-spatial-resolution remote sensing satellite data, and then constructed a 10 m-size emission grid and monthly SFD emission inventories based on the wind erosion equation by inputting vegetation cover factor, meteorological data, and soil erosion index. The total emissions of TSP, PM₁₀, and PM_2.5 in Daxing District from 2020 to 2022 were 3996.54 tons, 359.26 tons, and 25.25 tons, respectively. Temporally, the SFD emissions showed a decreasing trend over the years and were mainly concentrated in the winter and spring seasons. Spatially, the SFD emissions were predominantly concentrated in the southern and northern areas. And the emissions of PM₁₀ exhibit a significantly stronger correlation with wind speed and the extent of bare soil area. Full article

Wind-induced waves can lead to the partial or complete wash-over of beaches, causing erosion that impacts both the landscape and tourist infrastructure. In some regions of the world, e.g., Croatia, this process, which usually occurs during a harsh winter, has a major impact on the environment and the economy, and preventing or reducing this process is highly desirable. One of the simplest methods to reduce or prevent beach erosion is the use of innovative underwater structures designed to decrease wave energy by reducing wave height. In this study, submerged breakwaters are numerically investigated using various topologies, positions, and angles relative to the free surface. Not only is the optimal topology determined, but the most efficient arrangement of multiple breakwaters is also determined. The advantage of newly developed submerged breakwaters over traditional ones (rock-fixed piers) is that they do not require complex construction, massive foundations, or high investment costs. Instead, they comprise simple floating bodies connected to the seabed by mooring lines. This design makes them not only cheap, adaptable, and easy to install but also environmentally friendly, as they have little impact on the seabed and the environment. To evaluate wave damping effectiveness, the incompressible computational fluid dynamics (ICFD) method is used, which enables the use of a turbulence model and the possibility of accurate wave modelling. Full article

The source region of the Yellow River (SRYR), known as the “Chinese Water Tower”, is currently grappling with severe soil erosion, which jeopardizes the sustainability of its alpine grasslands. Large-scale soil erosion monitoring poses a significant challenge, complicating global efforts to study soil erosion and land cover changes. Moreover, conventional methods for assessing soil erosion do not adequately address the variety of erosion types present in the SRYR. Given these challenges, the objectives of this study were to develop a suitable assessment and prediction model for soil erosion tailored to the SRYR’s needs. By leveraging soil erosion data measured by ¹³⁷Cs from 521 locations and employing the random forest (RF) algorithm, a new soil erosion model was formulated. Key findings include that: (1) The RF soil erosion model significantly outperformed the revised universal soil loss equation (RUSLE) model and revised wind erosion equation (RWEQ) model, achieving an R² of 0.52 and an RMSE of 5.88. (2) The RF model indicated that from 2001 to 2020, the SRYR experienced an average annual soil erosion modulus (SEM) of 19.32 t·ha⁻¹·y⁻¹ with an annual total erosion in the SRYR of 225.18 × 10⁶ t·y⁻¹. Spatial analysis revealed that 78.64% of the region suffered low erosion, with erosion intensity declining from northwest to southeast. (3) The annual SEM in the SRYR demonstrated a downward trend from 2001 to 2020, with 83.43% of the study area showing improvement. Based on these findings, measures for soil erosion prevention and control in the SRYR were proposed. Future studies should refine the temporal analysis to better understand the influence of extreme climate events on soil erosion, while leveraging high-resolution data to enhance model accuracy. Insights into the drivers of soil erosion in the SRYR will support more effective policy development. Full article

The Karnak Temples complex, a monumental site dating back to approximately 1970 BC, faces significant preservation challenges due to a confluence of mechanical, environmental, and anthropogenic factors impacting its stone blocks. This study provides a comprehensive evaluation of the deterioration affecting the northeast corner of the complex, revealing that the primary forms of damage include split cracking and fracturing. Seismic activities have induced out-of-plane displacements, fractures, and chipping, while flooding has worsened structural instability through uplift and prolonged water exposure. Soil liquefaction and fluctuating groundwater levels have exacerbated the misalignment and embedding of stone blocks. Thermal stress and wind erosion have caused microstructural decay and surface degradation and contaminated water sources have led to salt weathering and chemical alterations. Multi-temporal satellite imagery has revealed the influence of vegetation, particularly invasive plant species, on physical and biochemical damage to the stone. This study utilized in situ assessments to document damage patterns and employed satellite imagery to assess environmental impacts, providing a multi-proxy approach to understanding the current state of the stone blocks. This analysis highlights the urgent need for a multi-faceted conservation strategy. Recommendations include constructing elevated platforms from durable materials to reduce soil and water contact, implementing non-invasive cleaning and consolidation techniques, and developing effective water management and contamination prevention measures. Restoration should focus on repairing severely affected blocks with historically accurate materials and establishing an open museum setting will enhance public engagement. Long-term preservation will benefit from regular monitoring using 3D scanning and a preventive conservation schedule. Future research should explore non-destructive testing and interdisciplinary collaboration to refine conservation strategies and ensure the sustained protection of this invaluable historical heritage. Full article

The Loess Plateau is an important source of particulate matter pollution in North China. In order to establish and repair shelterbelts and improve their function of inhibiting wind erosion and dust, four typical shelterbelts (Populus simonii, Pinus tabulaeformis Carr., Pinus tabulaeformis Carr. × Populus simonii and Caragana korshinskii Kom.) were selected to investigate the inhibition rate of soil wind-erosion and the reduction rates of PM₁, PM_2.5 and PM₁₀ by stand type, stand structure and soil properties. A sample plot survey and semi-fixed observation method were used to measure wind speed and particulate matter concentration and to calculate wind protection effect, sand transport rate, vertical flux of particulate matter, wind-erosion inhibition rate and particulate matter reduction rate. The results showed that the Pinus tabulaeformis Carr. forest and Caragana korshinskii Kom. forest had the best windproofing effect, at 2 m (82.9% ± 23.8%) and 0.5 m (54.4% ± 21.5%), respectively. The distribution curve of the sediment flux of shelterbelts is a logarithmic function. The wind-erosion inhibition rate and PM₁ reduction rate of the Pinus tabulaeformis Carr. forest were significantly greater than those of other stand types (p < 0.05). The generalized linear mixed model (GLMM) shows that the DBH variation coefficient (CV) can effectively explain the reduction rate of PM₁. It is suggested that policies be enacted to add or replace Pinus tabulaeformis Carr. forest in polluted areas to prevent wind erosion and dust. Full article

Soil degradation has led to a continuous decline in the quality of phaeozem, which is seriously threatening the foundation of national food security. Therefore, precisely evaluating the health status of phaeozem resources and their spatial and temporal variations are crucial for ensuring the effective implementation of soil degradation prevention and control strategies. In this study, soil data from 140 sites were collected, and eight physical and chemical indices (sand content, silt content, pedon thickness, organic matter, total potassium, total nitrogen, total phosphorus, and pH) were utilized to assess the soil health status of phaeozem in Liaoning Province. The results showed the following: (1) The minimum data set is aligned with previous research findings and effectively mirrors the soil’s health condition. (2) The substantial coefficients of variation observed for pedon thickness, sand content, and silt content across regions suggest notable differences, likely influenced by climatic variations, parent material differences, and anthropogenic activities. (3) The study area’s average soil pH of 6.39 indicates an overall acidic nature, potentially attributed to intense soil weathering and suboptimal fertilization practices. (4) The soil health index (SHI) ranged from 0.33 to 0.91, with an average of 0.62, which indicates that the majority of the phaeozem in Liaoning Province are in a sub-healthy state (SHI < 0.6 = unhealthy, SHI 0.6–0.8 = sub-healthy, SHI ≥ 0.8 = healthy). These sub-healthy areas are primarily located in hills, mountains, and the Liaohe Plain, and are significantly impacted by rainfall and wind erosion. Meanwhile, unhealthy areas are concentrated in the south and center of the province, characterized by fragile ecological environments and challenging agricultural conditions. Full article

Freeze–thaw (FT) erosion intensity may exhibit a future increasing trend with climate warming, humidification, and permafrost degradation in the Qinghai–Tibet Plateau (QTP). The present study provides a reference for the prevention and control of FT erosion in the QTP, as well as for the protection and restoration of the regional ecological environment. FT erosion is the third major type of soil erosion after water and wind erosion. Although FT erosion is one of the major soil erosion types in cold regions, it has been studied relatively little in the past because of the complexity of several influencing factors and the involvement of shallow surface layers at certain depths. The QTP is an important ecological barrier area in China. However, this area is characterized by harsh climatic and fragile environmental conditions, as well as by frequent FT erosion events, making it necessary to conduct research on FT erosion. In this paper, a total of 11 meteorological, vegetation, topographic, geomorphological, and geological factors were selected and assigned analytic hierarchy process (AHP)-based weights to evaluate the FT erosion intensity in the QTP using a comprehensive evaluation index method. In addition, the single effects of the selected influencing factors on the FT erosion intensity were further evaluated in this study. According to the obtained results, the total FT erosion area covered 1.61 × 10⁶ km², accounting for 61.33% of the total area of the QTP. The moderate and strong FT erosion intensity classes covered 6.19 × 10⁵ km², accounting for 38.37% of the total FT erosion area in the QTP. The results revealed substantial variations in the spatial distribution of the FT erosion intensity in the QTP. Indeed, the moderate and strong erosion areas were mainly located in the high mountain areas and the hilly part of the Hoh Xil frozen soil region. Full article

Wind turbine blades are essential parts of wind energy systems and are frequently exposed to harsh environmental elements, such as strong winds, turbulence, and corrosive atmospheric elements. Over time, these circumstances may result in serious harm to blades, such as delamination and erosion, which may negatively affect the wind turbine’s functionality and durability. Accurate prediction of various types of damage is crucial to improve the toughness and lifespan of wind turbine blades and to maximize the overall effectiveness of wind energy systems. This article presents a novel computational fluid dynamics (CFDs)-based method for analyzing the distribution of wall shear stress on turbine blades, aimed at publicizing the yearly maintenance procedure. The investigation results from the CFDs, when compared with the current situation in a wind turbine farm in Thailand, confirmed that our wall shear stress modeling accurately predicted wind turbine damage. A maximum wall shear stress level higher than 5.00 Pa in the case of PA 90°, incoming air velocity 10.00 m/s, and 15 rpm was the main contribution to presenting the erosion and delamination from current drone inspection in wind turbine farms. In conclusion, these findings demonstrated the potential of using CFDs to predict wind turbine blade delamination and erosion, thereby significantly contributing to the development of specific and accurate yearly preventive maintenance. The proposed CFDs-based approach should serve as a sustainability tool for local human development, benefiting wind turbine engineers and operating technicians by providing them with a deeper understanding of the local flow conditions and wall shear stress distribution along wind turbine blades. This enables them to make informed decisions regarding blade design and maintenance. Full article

Wind erosion is a key global environmental problem. As an important protective measure to provide services to the ecosystems in wind-eroded areas, the wind erosion prevention service is of great significance to the management of wind and sand hazards and ecological environment restoration in the wind-eroded areas and the neighboring areas. Taking the Shiyang River basin as the study area, the quality of supplies for wind erosion prevention services was estimated using the RWEQ model for the years 2005, 2010, 2015, and 2020; the trajectories of air masses at wind speeds higher than the sand-causing wind speeds were simulated based on the forward trajectory module of the HYSPLIT model for a 24 h period; the spatial simulation of the flow of wind erosion prevention services on a daily scale with Minqin Station as the sand source was carried out; and the beneficiary areas of wind erosion prevention services were identified. Based on the RWEQ model, the spatial patterns of potential wind erosion, actual wind erosion, and wind and sand stabilization services were obtained, and the supply areas were divided. From 2005 to 2020, the wind erosion prevention service flow in the Shiyang River basin was distributed along a northwest–southeast direction, with a radial decrease from the center to the periphery, and with an extremely strong extraterritorial effect. The amount of wind erosion in the basin has a variable downward tendency over time and a spatial distribution pattern of high in the north and low in the south. The area of higher sand fixation is distributed in the eastern oasis area and desert junction zone. The HYSPLIT model was used to simulate the transport paths of wind and sand within 24 h during 2005–2020, the transmission paths of the wind erosion prevention service flow were obtained to be 59–134, and the flows were 2.55 × 10⁴–3.85 × 10⁶ t, displaying a changing trend of first decreasing, then increasing, and then decreasing. Gansu Province, Ningxia Hui Autonomous Region, and Inner Mongolia Autonomous Region are the most important areas benefiting from the wind erosion prevention service flow in the Shiyang River basin. The wind erosion prevention service flows in the basin benefit 47 cities in 9 provinces. Full article

Effective land management in the Djeffara plain, southeastern Tunisia, is being constrained by increasing land degradation issues due to arid climate conditions and soil erosion. Thus, this study aims to assess the impact of the integrated control measures, namely windbreaks and controlled grazing, on the restoration of land cover dynamics in six managed rangeland areas. Land cover changes were monitored using satellite data and the derived vegetation indices (the normalized difference vegetation index (NDVI) and the soil-adjusted vegetation index (SAVI)) from Landsat 8 (OLI), both within and outside the protected areas. The findings reveal that the implemented protection measures lead to an increase in vegetation cover, diversity, and plant density. They play an important role in stabilizing the upper soil layer. The oldest protected areas, particularly those that are well-maintained with controlled seasonal grazing, experienced a reduction in sand movement. The reintroduction of grazing should, however, be controlled to prevent degradation risks. The results show strong correlations between vegetation cover and both calculated vegetation indices, (0.73 < R² < 0.91), with more accurate estimating for the SAVI. The findings of this research can guide decision-makers for restoring degraded rangelands and planning effective control measures for wind erosion. Full article

Desert vegetation in the outer transition zone of an arid oasis serves as a protective barrier against wind and sand, safeguarding the oasis ecosystem. However, intensive agricultural water usage within the oasis has led to water depletion, posing a threat to the survival and growth of desert vegetation, as well as the associated increase in wind and sand phenomena. To ensure the sustainable distribution of water resources and maintain the stability of the oasis peripheral ecosystem, this study aimed to investigate the relationship between the ecological water demand of desert vegetation and its effectiveness in preventing wind erosion. Through a combination of field sample tests, field pit tests, and data analysis, this research focused on Haloxlon ammodendron, the most prevalent species on the oasis periphery, to explore the intricate relationship between its ecological water demand and resistance to wind erosion. The results showed that medium-vegetation-coverage soils exhibited a higher soil moisture content (7.02%) compared to high-vegetation-coverage soils (1.57%) and low-vegetation-coverage soils (3.41%). As the soil water content decreased, the growth rate of H. ammodendron’s plant height, new branches, and crown width decelerated. The ecological water requirement of H. ammodendron during its growth period was 70.95 mm under medium-vegetation-coverage conditions, exhibiting a significant increase of 14.6% and 12.3% compared to high- and low-vegetation-coverage conditions, respectively. Meanwhile, H. ammodendron exhibits remarkable wind erosion prevention effects in moderate coverage conditions, resulting in a significant reduction in surface sand collection and sand transport by 53.15% and 51.29%, respectively, compared to low vegetation coverage; however, no significant difference was observed when compared to high vegetation coverage. The SEM model results revealed that soil water content had an indirect effect on sand transport (R² = 0.90) and sand collection (R² = 0.96) through three pathways of action, namely: volatile water content–crown growth rate–wind speed–sediment discharge; volatile water content–plant height growth rate–vegetation coverage–wind speed–sediment discharge; and volatile water content–plant height growth rate–vegetation coverage–sediment accumulation. This study provides valuable insights for the scientific formulation and implementation of strategies aimed at protecting desert vegetation. Full article

The abandonment of ancestral techniques and the incorporation of new technologies in the production systems for the cultivation of quinoa has resulted in overexploitation of soils, a loss of fertility, water imbalance, a loss of native vegetation cover in plain land areas, and other negative effects on the southern Altiplano agricultural sustainable system. One of the methods to reduce wind erosion and improve soil environmental conditions is establishing a native vegetative barrier. The effect of t’ola [Parastrephia lepidophylla (Wedd.) Cabrera] as a vegetative barrier to prevent wind erosion was evaluated using the rod method, gravimetric humidity fluctuations, and soil quality measurements in traditional quinoa Real production plots. We found significant differences (p < 0.05) for mean erosion, sedimentation, net erosion, and mobilized soil variables. The highest loss of soil was reported for December and November. Vegetative barriers comprising three meters of t’ola better protected bare soils up to 7 m from the barrier, while in bare soils, the loss values were over 5 t ha⁻¹ month⁻¹. Soil humidity fluctuations in plots with t’ola vegetative barriers were highly significant for the distance factors and depth levels. There was a higher accumulation of gravimetric humidity (%) in bare soils from 1.5 m to the barrier (6.95%), while the insides of the vegetative barriers retained an average soil humidity of 6.37%. After two agricultural seasons in the quinoa plots, 62 t ha⁻¹ per year of soils were lost due to a lack of vegetative barriers. Due to the large, cultivated area with quinoa (104,000 ha in 2014) in the Intersalar zone, wind erosion causes 6.48 million tons of soil loss yearly. T’ola vegetative barriers in the southern Altiplano of Bolivia favour the retention of sediments against wind erosion and soil protection for quinoa cultivation. Furthermore, incorporating native lupine increased soil fertility by 80% and protected the soil surface cover. Full article