Search Results (68)

A system of field protective forest belts (FPFBs) was created in the middle of the 20th century in Southern Dobrudzha (Northern Bulgaria) to reduce wind erosion, improve soil moisture storage, and increase agricultural crop yields. Since 2020, prolonged climatic drought during growing seasons and the advanced age of trees have adversely impacted the health status of planted species and resulted in the decline and dieback of the FPFBs. Physiologically stressed trees have become less able to resist pests, such as insects and diseases. In this work, an original new methodology for the integrated assessment of the condition of FPFBs and their protective capacity is presented. The presented methods include the assessment of structural and functional characteristics, as well as the health status of the dominant tree species. Five indicators were identified that, to the greatest extent, present the ability of forest belts to perform their protective functions. Each indicator was evaluated separately, and then an overlay analysis was applied to generate an integrated assessment of the condition of individual forest belts. Three groups of FPFBs were differentiated according to their condition: in good condition, in moderate condition, and in bad condition. The methodology was successfully tested in Southern Dobrudzha, but it could be applied to other regions in Bulgaria where FPFBs were planted, regardless of their location, composition, origin, and age. This methodological approach could be transferred to other countries after adapting to their geo-ecological and agroforest specifics. The methodological approach is an informative and useful tool to support decision-making about FPFB management, as well as the proactive planning of necessary forestry activities for the reconstruction of degraded belts. Full article

In arid and semi-arid areas, soil is blown up by the wind because of its loose structure. Wind erosion causes soil quality and fertility loss, land degradation, air pollution, disruption of ecological balance, and agricultural and livestock losses. Consequently, there is an immediate imperative for methods to mitigate the impacts of wind erosion. SICP (soybean urease-induced carbonate precipitation) has emerged as a promising biogeotechnical technology in mitigating wind erosion in arid and semi-arid regions. To enhance bio-cementation efficacy and treatment efficiency of SICP, aluminum chloride (AlCl₃) was employed as an additive to strengthen the SICP process. Multiple SICP treatment cycles with AlCl₃ additive were conducted on Tengger Desert sand specimens, with the specimens treated without AlCl₃ as the control group. The potential mechanisms by which AlCl₃ enhances SICP may have two aspects: (1) its flocculation effect accelerates the salting-out of proteinaceous organic matter in the SICP solution, retaining these materials as nucleation sites within soil pores; (2) the highly charged Al³⁺ cations adsorb onto negatively charged sand particle surfaces, acting as cores to attract and coalesce free CaCO₃ in solution, thereby promoting preferential precipitation at particle surfaces and interparticle contacts. This mechanism enhances CaCO₃ cementation efficiency, as evidenced by 2.69–3.89-fold increases in penetration resistance at the optimal 0.01 M AlCl₃ concentration, without reducing CaCO₃ production. Wind erosion tests showed an 88% reduction in maximum erosion rate (from 1142.6 to 135.3 g·m⁻²·min⁻¹), directly correlated with improved microstructural density observed via SEM (spherical CaCO₃ aggregates at particle interfaces). Economic analysis revealed a 50% cost reduction due to fewer treatment cycles, validating the method’s sustainability. These findings highlight AlCl₃-modified SICP as a robust, cost-effective strategy for wind erosion control in arid zones, with broad implications for biogeotechnical applications. Full article

This study explored the enzymatic formation of gel-like polymeric matrices through carbonate precipitation for dust suppression in Yellow River silt. The hydrogel-modified EICP method effectively enhanced the compressive strength and resistance to wind–rain erosion by forming a reinforced bio-cemented crust. The optimal cementation solution, consisting of urea and CaCl₂ at equimolar concentrations of 1.25 mol/L, was applied to improve CaCO₃ precipitation uniformity. A spraying volume of 4 L/m² (first urea-CaCl₂ solution, followed by urease solution) yielded a 14.9 mm thick hybrid gel-CaCO₃ crust with compressive strength exceeding 752 kPa. SEM analysis confirmed the synergistic interaction between CaCO₃ crystals and the gel matrix, where the hydrogel network acted as a nucleation template, enhancing crystal bridging and pore-filling efficiency. XRD analysis further supported the formation of a stable gel-CaCO₃ composite structure, which exhibited superior resistance to wind–rain erosion and mechanical wear. These findings suggest that gel-enhanced EICP represents a novel bio-gel composite technology for sustainable dust mitigation in silt soils. Full article

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

Combining the Microbial-Induced Calcium Carbonate Precipitation (MICP) technique with plants to reinforce calcareous sand slopes on reef islands is expected to achieve both reinforcement and economic benefits. In this study, MICP was combined with Festuca arundinacea (MICP-FA) for calcareous sand reinforcement. Based on water retention and scanning electron microscopy (SEM) tests, the water retention performance and mechanism of MICP-reinforced calcareous sand under different cementation solution concentrations and cementation cycles were analyzed. The growth adaptability of Festuca arundinacea was evaluated under different bacteria solution concentrations, cementation solution concentrations and cementation cycles. The engineering applicability of MICP-FA-reinforced calcareous sand was evaluated by wind erosion tests, and the synergistic reinforcement mechanism was analyzed. The results show that with the increase in the cementation solution concentration and cementation cycles, more calcium carbonate filled and adhered to the calcareous sand particles, significantly improving the water retention performance. MICP-FA can enhance the wind erosion resistance of calcareous sand. This synergistic mechanism lies in the surface cementation effect of MICP and the deep anchoring effect of plant roots. This study provides theoretical basis and technical guidance for engineering applications in calcareous sand areas. Full article

Wind erosion significantly threatens sustainable development in desert regions, causing severe soil degradation. Investigating the influence of roughness elements on wind–sand interactions is vital for devising effective wind erosion control strategies. This study examined the effects of smooth and porous surface roughness elements on wind–sand activity and the wind erosion rate of a sand bed surface. Wind tunnel experiments were conducted with 10% coverage of these elements on the sand bed surface under varying wind speeds. Results showed that porous-surfaced roughness elements were less responsive to wind speed than smooth-surfaced spherical elements, significantly slowing wind erosion and enhancing sand bed stability. The porous-surfaced elements significantly reduced wind erosion rates by 21.8% at low wind speeds (8 m/s) and 18.23% at high wind speeds (14 m/s), compared to smooth-surfaced elements. The porous-surfaced spherical roughness elements effectively reduced the secondary lifting of sand particles by increasing the specific surface area, thereby improving the bed surface’s wind erosion resistance. These findings provide critical insights for optimizing sand control materials and developing more effective wind erosion mitigation strategies, offering a valuable reference for combating desertification. Full article

Mine ramps, serving as a critical transportation hub in underground mining activities, are beset by severe issues of dust pollution and secondary dust generation. While dust suppressants are more efficient than the commonly used sprinkling methods in mines, traditional single-function dust suppressants are inadequate for the complex application environment of mine ramps. Building on the development of conventional single-function dust suppressants, this research optimized the components of bonding, wetting, and moisturizing agents. Through single-factor optimization experiments, a comparison was made of the surface tension water retention property and viscosity of diverse materials, thus enabling the identification of the primary components of the dust suppressant. By means of synergistic antagonism experiments, the optimal combination of the wetting agent and bonding agent with excellent synergy was ascertained. Ultimately, the wind erosion resistance and rolling resistance were measured through three-factor orthogonal experiments, and the optimal ratio of the dust suppressant was established. Specifically, fenugreek gum (FG) was selected as the bonding agent, cane sugar (CS) as the moisturizing agent, and alkyl phenol polyoxyethylene ether (Op-10) as the wetting agent. The research findings demonstrate that the optimal ratio of dust suppressant is 0.3 wt% fenugreek gum (FG) + 0.06 wt% alkyl phenol polyoxyethylene ether (Op-10) + 3 wt% cane sugar (CS). Under these conditions, the dust fixation rate can reach up to 97~98% at a wind speed of 8 m/s. The maximum rolling resistance can reach 65~73% after grinding the samples for 1 min. The surface tension of the solution is 13.74 mN/m, and the wetting performance improved by 81% compared to pure water. This dust suppressant is of great significance for improving the working environment of workers and ensuring the sustainable development of the mining industry. Full article

Enzyme-induced carbonate precipitation has been studied for wind erosion control in arid areas. A comparative study was conducted between the pure urease- and crude soybean urease-induced carbonate precipitation methods with the same enzyme activity for enhancing the wind erosion resistance of desert sand. Tube tests were carried out to monitor the amount of organic matter and CaCO₃ precipitates at different reaction times. Two groups of sand specimens received several cycles of treatment with soybean urease (SU) and pure urease (PU), respectively, with urea or without urea. The treated specimens were exposed to wind-blown sand flow to evaluate erosion resistance. The results showed that SU induced more organic precipitation under the salting-out effect, which was 9.88 times higher than that from PU. Under the one-cycle treatment, SU-treated specimens with higher contents of CaCO₃ and organic matter exhibited lower erosion mass. Under the multiple-cycle treatment, the high viscosity of SU and rapid precipitation of organic matter resulted in the inhomogeneous distribution of CaCO₃ (more precipitation at the top). Once the top of SU-treated specimens was eroded, the sand below the top layer was lost rapidly, causing the erosion mass of PU-treated specimens to be 95% lower than that of SU-treated specimens. Full article

This study aims to investigate the impact of a self-developed environmentally friendly composite dust suppressant on soil properties, with the objective of addressing dust pollution at construction sites. A series of experiments were conducted to examine the effects of the composite dust suppressant on soil strength (including compressive strength, shear strength, and surface hardness) and wind erosion resistance. The results demonstrate that spraying the soil with the composite dust suppressant diluted 10 times not only significantly enhances the compressive strength and ductility of the soil but also reduces the usage cost. Furthermore, the soil treated with the diluted suppressant exhibited the highest ultimate compressive strength after drying for seven days, which was 118.1 kPa higher than that of the undiluted treatment. The shear strength test also revealed a substantial increase in the shear strength of the soil treated with the dust suppressant under different vertical loads. Hardness tests showed that the composite dust suppressant containing binder significantly improved soil hardness. Wind erosion resistance tests further confirmed that the soil sprayed with the composite dust suppressant had a mass loss rate of only 9.36% within twenty minutes under an eleven-grade natural wind force, demonstrating good wind erosion resistance. This study not only provides a scientific basis for assessing the environmental impact of environmentally friendly composite dust suppressants on soil but also offers standardized evaluation techniques and experimental protocols for practical applications of dust suppressants. Full article

Protective forests are vital to ecological security in arid desert regions, but their spatial distribution is often inefficient. This study aims to optimize the spatial distribution of protective forests in Alaer City using a combination of the Non-dominated Sorting Genetic Algorithm-II (NSGA-II) and the Future Land Use Simulation (FLUS) model. The optimization focuses on three objectives: economic benefits, ecological benefits, and food security. A neural network model is applied to analyze forest distribution suitability based on spatial factors. The results show that the optimized distribution significantly enhances GDP, carbon sequestration, water yield, and food production, while reducing soil erosion. The forest area is mainly concentrated along rivers, agricultural fields, and desert edges, with increased coverage at the Taklamakan Desert’s periphery improving wind and sand resistance. The FLUS model is validated with high accuracy (90.73%). This study provides a theoretical foundation for the sustainable development of protective forests, balancing ecological and economic goals in Alaer City. Full article

Ice accumulation on wind turbine blades poses a significant challenge to turbine performance and safety, and these issues have led to extensive research on developing effective anti-icing methods. Polymer-based icephobic coatings have emerged as promising solutions, given their passive nature and low energy requirements. However, developing effective icephobic coatings is a complex task. In addition to anti-icing properties, factors such as mechanical strength, durability, and resistance to UV, weathering, and rain erosion must be carefully considered to ensure these coatings withstand the harsh conditions faced by wind turbines. The main challenge in coating engineering is mastering the chemistry behind these coatings, as it determines their performance. This review provides a comprehensive analysis of the suitability of current icephobic coatings for wind turbine applications, emphasizing their alignment with present industrial standards and the underlying coating chemistry. Unlike previous works, which primarily focus on the mechanical aspects of icephobicity, this review highlights the critical yet underexplored role of chemical composition and explores recent advancements in polymer-based icephobic coatings. Additionally, earlier studies largely neglect the specific standards required for industrial applications on wind turbines. By demonstrating that no existing coating fully meets all necessary criteria, this work underscores both the urgency of developing icephobic coatings with improved durability and the pressing need to establish robust, application-specific standards for wind turbines. The review also combines insights from cutting-edge research on icephobic coatings that are coupled with active de-icing methods, known as the hybrid approach. By organizing and summarizing these innovations, the review aims to accelerate the development of reliable and efficient wind energy systems to pave the way for a cleaner and more sustainable future. Full article

Gravel layers are vital ecological barriers in Gobi Desert mining areas. However, open-pit activities increase wind and soil erosion. Thus, the effects of fly ash addition, water content, and compaction on the shear strength and wind erosion resistance of soil crusts were explored by compaction tests, direct shear tests, and wind tunnel experiments. (1) The results of the direct shear test and vane shear test show that the modified soil sample achieved the maximum shear strength under the conditions of 15% fly ash content, 13% water content, and 3 compaction cycles. (2) The results of the wind tunnel test indicate that the wind erosion resistance of the gravel layer soil crust was improved after fly ash treatment. Compared to the untreated soil crust, the wind erosion amount of the treated soil was reduced by 23%. (3) Microscopic analysis revealed that hydration products from fly ash filled the soil pores, enhancing particle bonding and soil structure, using a scanning electron microscope (SEM) and an X-ray fluorescence spectrometer (XRF). (4) Considering the water scarcity in the Eastern Junggar Coalfield of China, a revised rehabilitation scheme was selected, involving 11% water content and single compaction, offering a balance between performance and economic efficiency. This study provides a novel approach to gravel layer restoration in arid mining regions using fly ash as a soil stabilizer, offering a sustainable method to enhance wind erosion resistance and promote fly ash recycling. Full article

Polyurethane coatings are widely used as protective layers against wear, mainly abrasive wear. They have recently been applied to surfaces exposed to erosive wear, such as wind turbine blades. This study investigated the abrasive and erosive wear of polyurethane elastomeric coatings with hardness values of 55 ShA, 75 ShA, and 95 ShA. The abrasive wear test was carried out using loose abrasive grains. The erosive wear test was carried out using a pressurized stream of gas containing abrasive particles. Both tests were carried out using aluminum oxide grains of five different sizes to evaluate the effect of particle size on wear behavior. Microscopic and profilometric analyses of the surface of the wear tracks were carried out. The mechanism of abrasive and erosive wear of polyurethane elastomeric coatings was determined. The results of the tests show a non-linear dependence of abrasive and erosive wear on the grain size. Furthermore, polyurethane elastomer coatings with a higher hardness exhibit a lower abrasive wear resistance but higher susceptibility to erosive wear. These findings provide insight into the trade-offs between hardness and wear performance, offering practical guidance for selecting polyurethane coatings in applications requiring resistance to combined abrasive and erosive wear. Full article

Shelterbelts provide essential protection against wind erosion and soil degradation, as well as protection for fruit-bearing plants and crops from strong winds. Enhancing their sheltering capabilities requires optimizing their pattern and orientation, as well as defining their height and desired canopy shape, according to the desired performance. In this work, Large Eddy Simulation is employed to investigate the flow field and windbreak effectiveness of single and double-arranged shelterbelts characterized by different geometry and resistance to the air passage for neutral atmospheric condition. In particular, the canopy of the shelterbelts is modeled as an isotropic porous medium immersed in atmospheric boundary layer flow using the Darcy–Forchheimer model. Results show that a shelterbelt with a rectangular-shaped cross-section and a large canopy height results in the most significant reduction in mean wind speed and TKE, thus providing a large wind-protection region. As the spacing distance of double-arranged shelterbelts increases, the protection zones formed by both shelterbelts are reduced. The systematic comparisons of flow patterns, drag force coefficients, and windbreak effectiveness indicators of a series of single and double-arranged shelterbelts are essential for optimizing the design and management of shelterbelts. Full article

Most earthen sites are located in open environments eroded by wind and rain, resulting in spalling and cracking caused by shrinkage due to constant water absorption and loss. Together, these issues seriously affect the stability of such sites. Gypsum–lime-modified soil offers relatively strong mechanical properties but poor water resistance. If such soil becomes damp or immersed in water, its strength is significantly reduced, making it unviable for use as a material in the preparation of earthen sites. In this study, we achieved the composite addition of a certain amount of sodium methyl silicate (SMS), titanium dioxide (TiO₂), and graphene oxide (GO) into gypsum–lime-modified soil and analyzed the microstructural evolution of the composite-modified soil using characterization methods such as XRD, SEM, and EDS. A comparative study was conducted on changes in the mechanical properties of the composite-modified soil and original soil before and after immersion using water erosion, unconfined compression (UCS), and unconsolidated undrained (UU) triaxial compression tests. These analyses revealed the micro-mechanisms for improving the waterproof performance of the composite-modified soil. The results showed that the addition of SMS, TiO₂, and GO did not change the crystal structure or composition of the original soil. In addition, TiO₂ and GO were evenly distributed between the modified soil particles, playing a positive role in filling and stabilizing the structure of the modified soil. After being immersed in water for one hour, the original soil experienced structural instability leading to collapse. While the water absorption rate of the composite-modified soil was only 0.84%, its unconfined compressive strength was 4.88 MPa (the strength retention rate before and after immersion was as high as 93.1%), and the shear strength was 614 kPa (the strength retention rate before and after immersion was as high as 96.7%). Full article