Prevention Of Erosion Research Articles

Understanding the role of topography on valley floor gully and hillslope gully development in cropland of the rolling hill region of northeast China

In regions with steep slopes, the classification of permanent gully (PG) into hillslope gullies (HG) and valley floor gullies (VG) was obvious before the study began. However, in the rolling hill region (slope < 5°), the difference between HG and VG was often overlooked. Moreover, there is no standardized approach for classifying gullies, which results in ambiguity regarding the impact of topography on various developmental stages of gullies and significantly impairs the effective management of gully erosion in the rolling hill region. We propose a remote sensing-based classification method to categorize 1081 PG into VG and HG in the cropland of the rolling hill region. The high-resolution satellite images (0.7 m) from 2010 and 2021 of all PGs were used to obtain the gully development rate and distribution patterns. Among these, 79 typical PGs were investigated using UAV to acquire high-resolution DEM (5 cm), which was used to analyze the relationship between the single or composite topographic factor and gully development rates. The results show that the proposed classification method can effectively recognize the VG and HG in the rolling hill region. The average length, area, and volume of the VG were found to be 2.31, 3.15, and 6.59 times that of the HG, respectively. The rate of gully head retreat, expansion area, and volume of the VG were also 1.59, 2.48, and 5.81 times faster than that of the HG, respectively. In HG and VG, the retreat rate of gully head (Δl) both showed a positive linear correlation with the distance from the gully head to the catchment divide (LA). The extension rate of gully area (Δa) was positively linearly and exponentially correlated with composite topographic factor SA (product of local slope (S) and contributing area above the gully head (A)). Additionally, the Δa of VG was strongly related to the shape and size of A, while the Δa of HG was strongly related to S. The gully volume expansion rate (ΔV) of both HG and VG was influenced by factors such as the existing size of the gully, the contributing area of the outlet (Ao), and the elevation difference from the outlet to the gully head (h). Hence, the changes in Δl and Δa for PG are primarily attributed to hydraulic erosion, while ΔV is influenced by both hydraulic and gravitational erosion. The study has shown the non-negligible influence of HG and VG in the rolling hill region. And the composite topographic factors can also better predict the PG development rate. This study contributes to the formulation of effective soil erosion prevention strategies and sustainable land management practices.

Attributing climate variability, land use change, and other human activities to the variations of the runoff-sediment processes in the Upper Huaihe River Basin, China

Study regionsThe Wangjiaba (WJB) watershed, located in the upper Huaihe River Basin in China. Study focusAn attributing framework has been proposed combining the Double Mass Curve (DMC) and the Soil and Water Assessment Tools (SWAT) model to identify the contributions of climate variability, Land use (LU) change, and Other Human Activities (OHA) to the variations in runoff-sediment processes within the WJB. New hydrological insights for the regionThe studied period was able to be separated into three sub-periods (P1: 1981~1991, P2: 1992~2009, and P3: 2010~2019) using the DMC, and the SWAT model could simulate runoff and Sediment Yields Load (SYL) properly during different sub-periods after calibration. Generally, the runoff, SYL, and Suspended Sediment Concentration (SSC) within the WJB exhibited a decrease trend with a change rate of −1.3mm a-1, −8.49×104 t a-1, and −0.01kgm-3 a-1, respectively. Substantially, climate variability decreases runoff, SYL, and SSC from P1 to P3; LU change decreases runoff, SYL, and SSC from P2 to P3; OHA decreases SYL and SSC from P1 to P2, but increases SYL and SSC from P2 to P3. It should be noticed that the OHA has increased the SYL significantly especially over the downstream of WJB from P2 to P3. It is essential to enhance soil erosion prevention measures in the future under the background of global climate change.

Spatiotemporal changes and management measure to enhance ecosystem services in the Mongolian Plateau

The eco-environment in many underdeveloped areas is vulnerable. Elucidating the changes and relationships in ecosystem services (ESs) is a fundamental basis for achieving sustainable development in these regions. Utilizing multiple data sources and models, we quantified water provision (WP), habitat quality (HQ), carbon fixation (CF), soil conservation (SC), and wind erosion prevention (WEP) on the Mongolian plateau during 1992-2018. We then analyzed the spatial-temporal changes, trade-offs/synergies, and bundles relationship of these ESs. The results indicated there was high spatial variability in five ESs across the plateau, with overall higher ESs in forested areas, and grassland and cropland areas had higher WEP values. The annual mean values of WP, HQ, CF, SC, and WEP in the plateau during 1992-2018 were 27.15 mm, 0.57, 176.17 gC·m2, 48.83 t·hm2, and 58.31 t·hm2, respectively. Due to fluctuations in precipitation, vegetation cover and land use, the five ESs decreased from 1992 to 2000s, but increased from 2000s to 2018, Notably, the HQ changed most significantly (p<0.01), while the WP changed insignificantly (p>0.05). The different ESs on the plateau overall exhibited synergistic effects, trade-offs between several pairs of ESs related to HQ, were observed in cropland areas. We further identified five distinct categories of ES bundles and proposed targeted recommendations for spatial planning and management of these ESs, tailored to their characteristics. The findings offer a valuable reference for high-quality environmental management, as well as the restoration and enhancement of ESs in arid inland areas in a warming climate.

Designing mouthwash formulations with innovative molecular components to control initial dental erosion in vivo.

This study aimed to examine and compare the efficacy of mouthwashes containing different proteins and peptide on the prevention of enamel erosion in vivo, as well as to evaluate the participants' satisfaction with the formulations. Twelve participants were selected and underwent five cross-over mouthwash phases: Water (control); 0.1mg/mL CaneCPI-5; 0.5mg/mL MaquiCPI-3; 0.1mg/mL CsinCPI-2; and 0.037mg/mL Stn15pSpS. After prophylaxis, the participants rinsed (1min), followed by the acquired enamel pellicle (AEP) formation (2h). An erosive challenge was made (biopsy, citric acid 1%, 15s) on the buccal surface of the central maxillary incisors. The Relative Surface Reflection Intensity (%SRI) was assessed and analyzed by ANOVA/Tukey's tests. The calcium release in acid was measured by the Arsenazo method and verified by Kruskal-Wallis/Dunn's tests. The Spearman's correlation was used between analyses. A questionnaire evaluated the satisfaction of participants. For both analyses, the results showed that mouthwashes containing the proteins or peptide were significantly more effective in preventing enamel erosion compared to deionized water, with no significant differences among the active ingredients (p < 0.05). Also, there was a significant negative correlation between %SRI and calcium released (r=-0.5754). The questionnaire revealed that the volunteers were satisfied with the taste of the products. In addition, the experimental procedures were well tolerable, and no side effects were reported. All mouthwashes containing proteins or peptide were acceptable and effective in protecting enamel against initial dental erosion in vivo. This study highlights the potential of these pioneer organic components for the development of mouthwashes designed for people with risk of erosive tooth wear.

Insights into local wall erosion characteristics and prevention measures for cyclone separators

Cyclone separators are separation devices that use the principle of inertia to remove particulate matter from flue gases. The present study mainly focuses on wall erosion in cyclone separators and associated research. The main locations of erosion in gas–solid cyclone separators, including the entrance impact section, cyclone roof corner, vortex finder outer surface, spiral-type erosion strip, and lower cone section, are examined in detail. The main factors influencing wall erosion are discussed, including inlet flow velocity, solid particle properties and loading, geometrical structure, and manufacturing quality. Finally, several practically preventive measures against wall erosion are presented, including adjustment of operating conditions, the use of erosion-resistant materials, optimization of geometrical structures, and the addition of auxiliary devices, all of which are essential for ensuring operational efficiency, equipment reliability, safety, and environmental protection in various industrial applications. This paper aims to provide a basis for further research into erosion in cyclone separators as well as guidance for engineers involved in their industrial applications.

Humans versus models: a comparative assessment of ecosystem services models and stakeholders’ perceptions

Mapping the production of Ecosystem Services (ES) is imperative for sustainable ecosystem management. Likewise, incorporating expert knowledge enhances ES research. Here, we calculate eight multi-temporal ES indicators for mainland Portugal using a spatial modelling approach. These indicators are then integrated into the novel ASEBIO index—Assessment of Ecosystem Services and Biodiversity—which depicts a combined ES potential based on CORINE Land Cover, using a multi-criteria evaluation method with weights defined by stakeholders through an Analytical Hierarchy Process (AHP). Outputs from the modelling show how ES have changed in Portugal in relation to land use changes, including trade-offs between 1990 and 2018. The composed ASEBIO index is compared against the stakeholders’ valuation of ES potential for the year 2018. The results reveal a significant mismatch between the ES potential perceived by stakeholders and the models, with stakeholder estimates being 32.8% higher on average. All the selected ES were overestimated by the stakeholders. Drought regulation and erosion prevention have the highest contrasts, while water purification, food production and recreation are the most closely aligned among both approaches. Providing the first national overview about the status of multiple ES over a 28 year-period, our findings highlight potential disparities between data-driven and stakeholder-based evaluations. Therefore, we suggest the need for integrative strategies that consider scientific models with expert knowledge for more effective ES assessments and land-use planning. This approach could help bridge the gap between data-driven models and human perspectives, resulting in more balanced and inclusive decision-making.

Research progress on coral reef growth factors and their ecosystem restoration

Healthy coral reef ecosystems have various functions such as reef-building, reef protection, reef stabilization, wave protection, shore protection, and the prevention of land erosion. Additionally, coral reef ecosystems are characterized by high biodiversity, often dubbed the “rainforest” of the ocean, as one of the most crucial ecosystems on Earth. In recent decades, global coral reefs have been significantly affected or damaged to varying degrees by climate change and human activities, posing threats to marine ecology and reef safety. This paper outlines the factors influencing coral reef growth, including global warming, ocean acidification, eutrophication, suspended solids, and tourism activities. It also discusses the status of coral reefs and viable restoration methods. Finally, this paper proposes an updated strategy for coral reef conservation, offering fresh insights into coral reef restoration efforts.

Enhancing Climate Resiliency Through Improving Ecosystem Services in Shoreline Municipalities – Lessons from Canada

The accelerated impacts of climate change in waterfront areas and the proven inefficacy of the aging hardened shoreline infrastructure have driven shoreline management practices to evolve toward the enhancement of ecosystem services at the land-water interface. Gaining momentum as an adaptive approach in regenerative projects, living shorelines are comprised of natural ecosystem components used in combination or in place of traditional hard engineering methods to provide coastal protective services and erosion mitigation. The success of living shorelines in protecting shoreline property and ecosystem integrity varies based on the biogeomorphology and hydrology of the region and is also heavily reliant on social acceptance of the chosen approach and best practice for implementation. The relatively lower lifecycle cost and associated co-benefits of living shorelines have well positioned them as a promising alternative approach in theory. There are, however, gaps in regional long-term datasets and evidence-based guidelines. This research provides an overview of the underlying geopolitical readiness for integrating nature-based solutions in climate adaptation strategies within shoreline municipalities based on a comprehensive literature review complimented by expert interviews. The synthesized data can inform decisions for minimizing the destructive effects of traditional shoreline erosion prevention approaches and encourage successful implementation of solutions that offer ecological, health, social, and economic benefits.

Dynamics of Sandy Shorelines and Their Response to Wave Climate Change in the East of Hainan Island, China

Beach erosion and shoreline dynamics are strongly affected by alterations in nearshore wave intensity and energy, especially in the context of global climate change. However, existing works do not thoroughly study the evolution of the sandy coasts of eastern Hainan Island, China, nor their responses to wave climate change driven by climate variability. This study focuses on the open sandy coast and assesses shoreline evolutionary dynamics in response to wave climate variability over a 30-year period from 1994 to 2023, using an open-source software toolkit that semi-automatically identify the shorelines (CoastSat v2.4) and reanalysis wave datasets (ERA5). The shorelines of the study area were extracted from CoastSat, and then tidal correction and outlier correction were performed for clearer shorelines. Combining the shoreline changes and wave conditions derived from ERA5, the dynamics of the shorelines and their response to wave climate change were further studied. The findings reveal that the average long-term shoreline change rate along the eastern coast of Hainan Island is 0.03 m/year, with 44.8% of transects experiencing erosion and 55.2% showing long-term accretion. And distinct evolutionary patterns emerge across different sections. Interannual variability is marked by alternating erosion and siltation cycles, while most sections of the coast experiences clear seasonal fluctuations, with accretion typically occurring during summer and erosion occurring in winter. El Niño–Southern Oscillation (ENSO) cycles drive changes in parameters including significant wave height, mean wave period, wave energy flux, and mean wave direction, leading to long-term changes in wave climate. The multi-scale behavior of the sandy shoreline responds distinctly to the ongoing changes in wave climate triggered by ENSO viability, with El Niño events typically resulting in accretion and La Niña periods causing erosion. Notably, mean wave direction is the metric most closely linked to changes in the shoreline among all the others. In conclusion, the interplay of escalating anthropogenic activities, natural processes, and climate change contributes to the long-term evolution of sandy shorelines. We believe this study can offer a scientific reference for erosion prevention and management strategies of sandy beaches, based on the analysis presented above.

Annual soil erosion characteristics of unpaved roads in the Loess Plateau hilly and gully region, China

The problem of unpaved road erosion is prominent in the Loess Plateau hilly and gully region. Unpaved roads contribute substantially to watershed sediment due to their high soil bulk density, low infiltration rates and extensive network. In this study, a field investigation was conducted on typical unpaved roads within a typical watershed in this region, focusing on assessing the damage state, annual soil loss and the factors influencing erosion in a comparatively wet year. The results showed that the soil erosion from unpaved roads was very severe, with an annual erosion intensity of 470 t hm−2, following three heavy rain events and two rainstorm events in the summer of 2022. The main unpaved roads (MUR) suffered the most severe road erosion, with 22.2 % of road segments experiencing severe erosion with classical gullies. The erosion gullies on the road had an average depth of 16.1 cm and an average width of 36.5 cm, with the widest being 146.0 cm and the deepest being 174.0 cm. The road erosion intensity was significantly related to drainage area, road area, road length and coverage. Road erosion reduced significantly when the land use in the drainage areas of the road was covered with shrub or grass, or road surface was covered with grass or gravel. Our findings offer valuable insights for road construction and erosion prevention in similar terrains.

Characteristics, impacts and future research directions of Mongolian peatlands

Mongolia is an important peatland distribution area in the world. Over the past few decades, Mongolian peatlands have undergone significant degradation due to climate change and human activities, yet there remains substantial uncertainty about the impacts of Mongolian peatland changes on regional environment and human society. Here, compiling the data of peatland distribution, climate, human activity, as well as the permafrost, we systematically review the distribution, changes, and the ecosystem service values of the Mongolian peatlands in the face of climate warming and intensifying human activities. The current data show that the total area of peatland in the Mongolian is 15500~27000 km2, and most of the peatlands are distributed in permafrost regions, while the accuracies of these maps were not assessed. In addition to climate warming, overgrazing, mining activities, and transportation, we suggest permafrost degradation also poses significant threatens on the peatlands. Although the importance of Mongolian peatlands has been recognized, the ecosystem service values, including water provision, habitat quality, carbon fixation, soil conservation, and wind erosion prevention largely remain unknown. Currently, efforts have been made to protect the Mongolian grassland, but there are no specific measures to combat peatland degradation. To better understand the changes and roles of peatland ecosystems in regulating regional development, we propose three research directions for future studies: 1) produce a detailed map of peatland distribution based on field survey data, new remote sensing data, and new algorithms; 2) Unveil the mechanisms underlying the interaction of peat, vegetation, and permafrost; 3) Evaluate the ecosystem services of Mongolian peatlands. These knowledges are the scientific foundation to propose and implement measures to protect, maintain, and sustainably utilize peatlands in Mongolia.

Experimental Study of Erosion Prevention Model by Bio-Cement Sand

Microbially induced carbonate precipitation (MICP) technology is employed to reinforce the surface soil of a dam, aiming to prevent erosion caused by water flow and damage to the dam slope. The relationship between penetration depth, calcium carbonate content, and bonding depth was investigated at eight measuring points on the sand slope surface of a mold under different reinforcement durations. It was observed that as grouting reinforcement times increased, there was a gradual increase in calcium carbonate content but a rapid rise in penetration resistance. Moreover, the bonding depth of sand on the bio-reinforced sand slope increased with higher levels of calcium carbonate content. Microbial grouting reinforcement enhanced soil particle bonding force, requiring water flow to overcome this force for activation of sand particles. Consequently, microbial grouting reinforcement significantly improved shear strength and critical starting flow velocity on sand slope surfaces. The experimental results demonstrated that after MICP surface treatment through spraying, a dense and water-stable hard shell layer composed of bonded calcium carbonate and soil particles formed continuously on sample surfaces, effectively enhancing the strength and erosion resistance of sandy soils. These findings provide reliable evidence for silt slope reinforcement and dam erosion prevention.

Impacts of post-operation loading and fixation implant on the healing process of fractured tibia.

Healing of tibia demonstrates a complex mechanobiological process as it is stimulated by the major factor of strains applied by body weight. The effect of screw heads and bodies as well as their pressure distribution is often overlooked. Hence, effective mechanical conditions of the healing process of tibia can be categorized into the material of the plate and screws, post-operation loadings, and screw type and pressure. In this paper, a mathematical biodegradation model was used to simulate the PGF/PLA plate-screw device over 8 weeks. The effect of different post-operation loading patterns was studied for both locking and non-locking screws. The aim was to reach the best configuration for the most achievable healing using FEA by computing the healing pattern, trend, and efficiency with the mechano-regulation theory based on deviatoric strain. The biodegradation process of the plate and screws resulted in 82% molecular weight loss and 1.05 GPa decrease in Young's modulus during 8 weeks. The healing efficiency of the cases ranged from 4.72% to 14.75% in the first week and 18.64% to 63.05% in the eighth week. Finally, an optimal case was achieved by considering the prevention of muscle erosion, bone density reduction, and nonunion, according to the obtained results.

Wind erosion prevention and trans-boundary ecosystem service payments in the Hunshandake region

Research on ecosystem services flow has attracted increasing interest as they provide essential knowledge to payments for ecosystem services (PES) by developing the spatial relationship between service benefit area and service providing area. In this study, we calculated the wind erosion prevention service (WEPS) in the Hunshandake region using the RWEQ model, simulated the WEPS flow trajectories using the HYSPLIT model, investigated the flow process of WEPS and its monetary values to develop the relationship between the beneficiary areas and the Hunshandake region, with the aim of proposing an integrated PES framework that links beneficiary areas to the Hunshandake region. The results indicated that the WEPS in the Hunshandake region were 2.67 × 1012 kg yr−1, 2.18 × 1012 kg yr−1, and 3.26 × 1012 kg yr−1 in 2010, 2015 and 2018, respectively, and their monetary values were 3.94 × 109 USD yr−1, 3.50 × 109 USD yr−1, and 4.93 × 109 USD yr−1, respectively. Most WEPS were transferred along the track to northern and northeastern China and continued on to Mongolia, Russia, North Korea, South Korea and Japan, while some were transported through central and eastern China to southern China and Southeast Asian countries. The Chinese beneficiary regions received between 69.75% and 70.81% of the total transferred WEPS from the Hunshandake region, with beneficiary countries outside of China receiving the remainder. We developed an integrated ecological payment framework based on the transferred values of WEPS and their demands in the beneficiary areas. The total payments for WEPS from beneficiary areas were 503.91 × 106 USD yr−1, 422.83 × 106 USD yr−1, and 609.18 × 106 USD yr−1 in 2010, 2015 and 2018, respectively. The ecological payments due from the beneficiary countries except China, the beneficiary provinces in China and the actual payments made as ecological fiscal transfers (EFT) from the Government of China; their percentages were 10.24%, 35.42% and 54.34%, respectively. Actualization of payments from benefitting countries and provinces within China were simulated with the percentage of EFT to the total transferred benefits in China decreasing from 60.54% to 40% and 20%; the value of payments from government would then reduce from 95.71 × 106 USD yr−1 to 63.24 × 106 USD yr−1 and 31.62 × 106 USD yr−1, respectively, alleviating the financial burden of government substantially. This study could provide a scientific basis for the government of China to formulate policies for payments from beneficiary provinces to Hunshandake region within China and facilitate negotiations with other countries on their potential payments to Hunshandake region providing WEPS to their benefit.

Magnitude and hotspots of soil erosion types during heavy rainstorm events on the Loess Plateau: Implications for watershed management

In the context of climate change, rainstorm events are becoming increasingly frequent. In particular, on the Loess Plateau, heavy rainstorms are the primary cause of soil erosion. This study investigated and analysed different types of soil erosion hotspots and influencing factors in small watersheds under different rainstorm events in different areas of the Loess Plateau. The results indicate that the erosion intensities of rills, gullies, landslides and collapses ranged from 13600-46244, 1982-772201, 1163-172153 t km-2 and 1867-94985 t km-2, respectively. Newly constructed terraces exhibited an erosion intensity 1.6 times greater than that of old terraces, while terraces constructed before the rainy season in the current year exhibited an erosion damage intensity 2.6 times greater than that of terraces constructed after the rainy season in the previous year. In addition, under rainstorm conditions, landslides represented the most severe type of erosion in the watersheds, with the maximum amount of erosion accounting for more than 90 % of the total erosion amount, followed by gully or collapse erosion, with the collapse of terrace risers as the main contributor. Slope cultivation land, unpaved roads, terrace risers, and valley slopes below the gully shoulder line were identified as erosion hotspot areas. Rainstorm erosion was significantly influenced by the land use type and slope, which explained 14.2 %-41.5 % and 9.7 %-15.1 %, respectively, of the total variance in erosion intensity. We suggest that soil erosion prevention and control efforts on the Loess Plateau should focus on landslides on valley slopes below gully shoulder lines, followed by gullies on unpaved roads and the collapse of terraced fields. Drainage ditches and water cellars should be constructed above the gully shoulder line and on the inside of roads and terraces, thereby reducing erosion. Our research is crucial for optimizing and adjusting watershed management measures and preventing rainstorm erosion disasters.

Hydrological Connectivity Response of Typical Soil and Water Conservation Measures Based on SIMulated Water Erosion Model: A Case Study of Tongshuang Watershed in the Black Soil Region of Northeast China

The black soil region of Northeast China is the largest commercial grain production base in China, accounting for about 25% of the total in China. In this region, the water erosion is prominent, which seriously threatens China’s food security. It is of great significance to effectively identify the erosion-prone points for the prevention and control of soil erosion on the slope of the black soil region in Northeast China. This article takes the Tongshuang small watershed (Heilongjiang Province in China) as an example, which is dominated by hilly landforms with mainly black soil and terraces planted with corn and soybeans. Based on the 2.5 cm resolution Digital Elevation Model (DEM) reconstructed by unmanned aerial vehicles (UAVs), we explore the optimal resolution for hydrological simulation research on sloping farmland in the black soil region of Northeast China and explore the critical water depth at which erosion damage occurs in ridges on this basis. The results show that the following: (1) Compared with the 2 m resolution DEM, the interpretation accuracy of field roads, wasteland, damaged points, ridges and cultivated land at the 0.2 m resolution is increased by 4.55–27.94%, which is the best resolution in the study region. (2) When the water depth is between 0.335 and 0.359 m, there is a potential erosion risk of ridges. When the average water depth per unit length is between 0.0040 and 0.0045, the ridge is in the critical range for its breaking, and when the average water depth per unit length is less than the critical range, ridge erosion damage occurs. (3) When local erosion damage occurs, the connectivity will change abruptly, and the remarkable change in the index of connectivity (IC) can provide a reference for predicting erosion damage.

Preventing Tax Base Erosion from Tax Treaty Abuse For SDGS in Vietnam

Objective: Tax treaties represent an important aspect of the international tax rules of many countries, especially in globalizing era. The taxing rights of the states is one of the biggest issues in cross border transactions because it decides the budget revenue deriving from tax. Tax base, tax base erosion and tax base erosion prevention are topics that have received a lot of attention recently in Vietnam in order to protect government’s revenue for sustainable development goals (SDGs). Method: By analyzing the current status of Vietnam's double taxation agreements (DTAs), the authors assessed the current situation and identifying risks of tax base erosion from abusing Vietnam's DTAs. The study focuses on analyzing the indicators to assess the content of DTAs such as the Source Index (SI), Permanent Establishment Index (PEI) and Withholding Tax Index (WHT) of Vietnam’s DTAs with the ones of groups of countries. Results: The authors found that there are loopholes in DTAs creating conditions for abuses of the terms of the agreements and causing tax base erosion in Vietnam. Comparing to the average level of developing countries, the DTA system of Vietnam is higher, however, the biggest limitation and the biggest risk from the system of DTAs are these agreements are agreements signed by Vietnam with the countries/territories that have the lowest scores and are in the group of countries/territories with the largest amount of investment capital in Vietnam. Contribution: The study makes some recommendations for Vietnam to prevent tax base erosion from tax treaty abuse by reviewing and considering negotiating to update the content of the bilateral tax agreements, promoting participation in multilateral tax agreement and improving efficiency of tax audit.

Simulation and Spatio-Temporal Analysis of Soil Erosion in the Source Region of the Yellow River Using Machine Learning Method

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.

Environmental Impact of River Bank Erosion on Stream Morphology: A Study of the Mini Piti Stream, Obio-Akpor, Nigeria

This study was designed to assess the impact of river bank erosion on the environment and the channel morphology for the Mini-Piti stream in Obio-Akpor local government area of Rivers State, Nigeria. This study determined the depth variations from width measurements due to bank erosion activities and the impact of indiscriminate waste dumps on the river channel. Physical water quality parameters of temperature, turbidity, transparency and TSS were determined using standard methods. The stream was divided into three stations; upstream 2.5km, midstream 2.5km, and downstream with intervals of 1km measured to differentiate each station as 5 samples were obtained per station at intervals of 0.5km apart. The flow velocity and discharge were estimated as the average depth recorded upstream being DS 0.9m, WS 1.4m, Midstream DS 1.3m, WS 1.7m, and Downstream = DS 1.5m WS 1.7m. The maximum width of 11m and minimum of 0.1m were recorded though natives confirmed that the stream is closing up unless maintenance dredging to expand the depth and width, the loss of this channel cannot exceed 20 years. The field observation and the impacts of precipitation and storm water from the built area of midstream were very intensive whose action increased the water level above its channel capacity and eroded the bank. From t-test analysis, there were significant seasonal variations in the depth for the measured widths for the upstream T (8) =2.1, p= 0.036 and the midstream, T (8) =2.36, p=0.023. Similarly using the one-ANOVA, a significant variation in the depths of five locations during the dry season downstream F (4, 60) = 2.79, p= .03 was recorded. The Tukey’s HSD post hoc test showed the locations have no significantly high depths for the studied widths sizes (p&lt;0.01 and p&lt;0.05). A one-way ANOVA revealed a significant variation in the depths of five locations during the wet season upstream F (4, 60) = 5.966, p= .000. The Tukey’s HSD post hoc test showed the locations have significantly high depths for the studied widths sizes (p&lt;0.01 and p&lt;0.05) at locations L2:L4 at Q=5.53 (p=0.00216, L2:L5 at Q= 4.72 (p=0.1214), L3:L4 at Q=4.90 (p=0.00841) and L3:L5 at Q=4.10 (p=0.0403). The studied physical parameters were all above WHO permissible standards and there were no significant variations between dry and wet seasons (38% turbidity midstream, TSS-33%, 31% and 30.6% variation upstream, midstream and downstream respectively) as well as spatial changes. The collapsed sediments and waste dumped at the bank of the stream were transported downstream due to reduced velocity and coarser sediments trapped at the stream bed causing shallow depth while the suspended fine sediment on the water column reduced the clarity of the stream resulting in adverse flooding over 20 years now. The research revealed that bank erosion has significant impact on water quality due to poor transparency and geometry of stream by the alterations of the channel depth and width, flow rate, scouring and deposition of sediments in the stream. The need for regulatory agencies to control anthropogenic inputs and enhance bank erosion prevention programmes cannot be over-emphasized. The monitoring of indiscriminate urbanization programmes to limit excess scouring activities by National Inland Waterways Authority (NIWA) is very essential to reduce excessive sand mining.

Deciphering Farm Pond Adoption Dynamics and Operational Efficiency in Drought-Prone Regions of Maharashtra, India

The study delves the dynamics of farm pond adoption and operational efficiency in the Vidarbha and Marathwada regions of Maharashtra during 2022-23. Through a combination of quantitative and qualitative methods, data were collected from 160 beneficiaries and 160 non-beneficiaries, employing focus group discussions and structured interviews. Agricultural risks were examined, revealing a significant impact on farm income. Challenges such as low ground water table (MS 0.978), high temperatures (MS 0.966), and least evapotranspiration (MS 0.759) affected farmers' livelihoods, underscoring the need for a multidisciplinary approach to address these issues. The study highlights factors influencing farm pond adoption, with high awareness (96.56%) contrasting with lower adoption rates (51.56%). Adopters cited increased water access (22.81%), and relief from water scarcity (20%) as motives. Non-adopters faced barriers like financial constraints (21.88%) and land shortage (18.75%). Farm pond characteristics were comprehensively explored, revealing variations in size, structure, year of adoption, and irrigation sources. Maintenance activities were examined, showcasing key areas for pond health. Regular inspection (31.88%), vegetation management (17.50%), sediment removal (25.63%), and erosion prevention (19.38 %) emerged as crucial tasks, with variations between the regions. Financial aspects of pond construction and maintenance were elucidated, indicating a need of subsidies. Despite widespread awareness of farm pond benefits, adoption rates remained constrained by financial limitations, land availability, and awareness gaps. The study underscores the importance of targeted interventions, including financial aid, technical guidance, and capacity-building. These efforts are essential for promoting widespread adoption, enhancing agricultural productivity, water management, and the resilience of farming communities in both regions.