Revised Wind Erosion Equation Model Research Articles

Trade-offs and synergistic relationships in wind erosion in Central Asia over the last 40 years: A Bayesian Network analysis

Wind erosion may have significant effects on both the environment and human activities. Central Asia, a prominently affected region by wind erosion on a global scale, has been the focus of a significant number of studies employing fundamental linear equations to establish causal relationships among the driving factors of wind erosion. However, such approaches neglect the imperative need for comprehensive analysis accounting for the intricate non-linear interactions among multiple factors, thereby potentially leading to distorted assessment outcomes. This study evaluated the multidimensional gradients (temporal, spatial, and vertical) of wind erosion in Central Asia over the last four decades using an enhanced version of the Revised Wind Erosion Equation (RWEQ) model. The Wind Erosion Modulus – Bayesian Network (WIEM-BN) model was developed by incorporating the Wind Erosion Modulus (WIEM) calculated by the RWEQ model as the parent node of the Bayesian Network (BN) and integrating multiple factors that influence the occurrence of wind erosion. The findings revealed a synergistic relationship between precipitation and the Normalized Difference Vegetation Index (NDVI), snowy days, and the Human Influence Index (HII), with trade-off correlations between temperature and precipitation and NDVI and soil moisture. The lowest overall WIEM level in Central Asia was associated with high HII and temperature (10–19 °C) as well as moderate precipitation (180–280 mm) and NDVI (0.18–0.24). Wind erosion in Central Asia varied substantially with Land Use Cover Change (LUCC), with the following drivers receiving precedence: wind speed > windy days > elevation > surface roughness (K') > HII > snowy days. Wind erosion was primarily caused by climate conditions (R = 0.741), with human activities (R = 0.629) acting as a suppressor. This study offered strategies to reduce wind erosion by up to 647.06 t km2 yr−1 in Central Asia, including a greater emphasis on ecological conservation programs and increased plant cover.

Spatiotemporal Evolution of Wind Erosion and Ecological Service Assessments in Northern Songnen Plain, China

The northern Songnen Plain in China is one of the most important areas for grain production in China, which has been increasingly affected by wind erosion in recent years. This study analyzed the dynamic spatiotemporal distribution of wind erosion in the northern Songnen Plain from 2010 to 2018 using the Revised Wind Erosion Equation model. The ecological service function of the study area was evaluated by constructing a spatial visualization map of windbreak and sand-fixation service flow. Wind erosion worsened from 2010 to 2018. The gravity center of different categories of wind erosion intensity moved to the northeast, indicating a risk of spreading from south to north. The amount of wind erosion in 2018 increased by 50.78% compared with 2010. The increase of wind force and temperature and the decrease of precipitation may have contributed to these trends. Long-term wind erosion led to soil coarsening, decreased soil organic matter, soil organic carbon, and total nitrogen contents, and increased soil CaCO3 and pH, which may be one reason for slight soil salinization observed in some regions. Therefore, windbreak and sand-fixation management and eco-environmental protection are urgently required. This study is the first detailed assessment of wind erosion in the northern Songnen Plain on a regional scale and the first to propose measures for ecological restoration and desertification control.

Analysis of Ecosystem Protection and Sustainable Development Strategies—Evidence Based on the RWEQ Model on the Loess Plateau, China

Environmental sustainability and high-quality development are global issues since soil deterioration and potential desertification are caused by human activities and global climate change, especially in arid and semi-arid areas. The Loess Plateau is one of the most severely eroded regions in the world. Since the “Grain for Green Program” was established on the Loess Plateau in the late 1990s as a result of the degradation of the soil, it has been an important state policy and demonstration project for ecological protection and sustainable development in China. Therefore, understanding the spatiotemporal changes of soil wind erosion, such as yearly and monthly fluctuations in various periods, under the scenarios of global climate change and human activities, is crucial for carrying out soil conservation initiatives in the Yellow River basin. The revised wind erosion equation (RWEQ) model was applied in this study to evaluate the dynamics of soil wind erosion on the Loess Plateau, China. The soil wind erosion was evaluated on the Loess Plateau from 1981 to 2019 to provide a creative idea for managing ecosystems at the regional scale. By examining the case of the Loess Plateau, we hope to be better able to comprehend the significance of putting environmental protection projects into action to enhance the ecological environment and the well-being of locals, as well as to offer recommendations for the future creation of effective and sustainable development strategies.

Evaluation of Inner Mongolia Wind Erosion Prevention Service Based on Land Use and the RWEQ Model

Inner Mongolia is the important ecological barrier zone in northern China, which plays an important role in the prevention and control of wind in the regional ecosystem. Based on the Revised Wind Erosion Equation (RWEQ) model and the cost-recovery method, this study simulated the wind erosion prevention service (WEPS) in Inner Mongolia in 2010 and 2015, investigated the spatial pattern of material and monetary value of WEPS, and analyzed the differences among various cities and various ecosystems. The results indicated that the total WEPS of Inner Mongolia was estimated to be 73.87×108 t in 2015, which was 4.61×108 t less than in 2010, while the monetary value of WEPS was calculated to be 738.66×108 yuan in 2015, which was 46.16×108 yuan less than in 2010. Among all the leagues and cities, Xilin Gol League supported the highest WEPS, reaching 18.65×108 t in 2015, while Wuhai provided the lowest. The WEPS of Hulunbeier increased the most, by 4.37×108 t from 2010 to 2015. The WEPS in the grassland ecosystem was the highest among the different ecosystems, accounting for more than 55% of the total WEPS in Inner Mongolia, but it was reduced by 1.05×108 t during the same period. The WEPS in the forest ecosystem increased the most, reaching 0.19×108 t. This study found that the implementation of projects such as returning farmland to forests and grasses and sand control effectively increased the WEPS by increasing the forest area. However, unsuitable land use increased the desertification of ecosystems which resulted in a reduction of WEPS in Inner Mongolia.

Evaluation of Qinghai-Tibet Plateau Wind Erosion Prevention Service Based on RWEQ Model

Ecosystem service research is essential to identify the contribution of the ecosystem to human welfare. As an important ecological barrier zone, the Qinghai-Tibet Plateau (QTP) supports the use of a crucial wind erosion prevention service (WEPS) to improve the ecological environment quality. This study simulated the spatiotemporal patterns of the WEPS based on the Revised Wind Erosion Equation (RWEQ) and its driving factors. From 2000 to 2015, the total WEPS provided in the QTP ranged from 1.75 × 109 kg to 2.52 × 109 kg, showing an increasing and then decreasing trend. The average WEPS service per unit area was between 0.72 kg m−2 and 1.06 kg m−2. The high-value areas were concentrated in the northwest and north of the QTP, and the total WEPS in different areas varied significantly from year to year. The average retention rate of the WEPS in the QTP was estimated to be 57.24–62.10%, and high-value areas were mainly located in the southeast of the QTP. The total monetary value of the WEPS in the QTP was calculated to be between 223.56 × 109 CNY and 321.73 × 109 CNY, and the average WEPS per unit area was between 0.08 CNY m−2 and 0.13 CNY m−2, showing a declining–rising–declining trend. The high-value areas gradually expanded to the west and east of the QTP. The slope was the most important factor controlling the spatial differentiation of the WEPS, followed by the landform type, average annual precipitation, and average annual wind speed, and human activities such as land-use change could improve the WEPS by returning farmland to grassland and desertification control in the QTP.

Global assessment of wind erosion based on a spatially distributed RWEQ model

Wind erosion is a global environmental problem and affects the sustainable use of land soil. The current efforts in wind erosion modeling mainly focus on local scales, yet very few studies have attempted to quantify the soil losses by wind on a large scale. Here, we proposed a distributed version of the revised wind erosion equation model (DRWEQ) to assess the spatial and temporal variations of wind erosion globally. The DRWEQ model used meteorological, soil, topographic, and remote sensing data to simulate global wind erosion from 2001 to 2010. The results showed that (a) the areas of wind erosion in Africa and Asia accounted for approximately 62% of the global wind erosion area but accounted for 91% of the global total soil loss; (b) global wind erosion showed a decreasing tendency during the research period – the wind erosion with a trend of intensification occupied 40.62% of the global wind erosion area while about 59.38% of the global wind erosion area showed a weakening trend; and (c) the monthly dynamics of the wind erosion were closely correlated with the combined effects of weather factors and vegetation coverage. The soil loss rates were lower in summer and reached the peak from January to April. The method presented in this study was developed based on the tradeoff of accuracy and availability of global data, and has the potential for predicting wind erosion from regional to global scales.

Wind erosion and its ecological effects on soil in the northern piedmont of the Yinshan Mountains

Soil erosion by wind is a serious problem that threatens ecological security and damages the ecological environment, thereby hindering the sustainable development of agriculture and animal husbandry in arid and semiarid areas. Using the northern piedmont of the Yinshan Mountains in the Inner Mongolia Autonomous Region of China as a study area, this study explores the spatiotemporal variation in soil loss by wind erosion and its impact on soil nutrients from 1990 to 2015. Various approaches, including remote sensing technology, the revised wind erosion equation model, the fallout cesium-137 tracing technique, and the geographic information system (GIS) spatial analysis technique, were jointly used in the present study. From 1990 to 2015, the soil loss by wind erosion obviously decreased, with a slope of −0.59 t/ha/a, in the study area. Affected by factors such as regional topography and wind direction, the wind erosion modulus is high in the northwest and low in the south and southeast of the northern piedmont of the Yinshan Mountains. The soil nutrient content decreased overall from 1990 to 2015, including a severe loss from 1990 to 2005 and a relatively low nutrient enrichment from 2005 to 2015. The decline in the sand-dust storm frequency and wind speed protected the soil from wind erosion. Implementing ecological management projects has played an important role in slowing wind erosion and enhancing the regional ability to resist wind erosion and fix sand. To improve soil quality and the regional ecological environment, ecological restoration projects should be further promoted in the study area.

Changes in wind erosion climatic erosivity in northern China from 1981-2016: a comparison of two climate/weather factors of wind erosion models

Wind erosion is largely determined by wind erosion climatic erosivity. In this study, we examined changes in wind erosion climatic erosivity during 4 seasons across northern China from 1981-2016 using 2 models: the wind erosion climatic erosivity of the Wind Erosion Equation (WEQ) model and the weather factor from the Revised Wind Erosion Equation (RWEQ) model. Results showed that wind erosion climatic erosivity derived from the 2 models was highest in spring and lowest in winter with high values over the Kumtag Desert, the Qaidam Basin, the boundary between Mongolia and China, and the Hulunbuir Sandy Land. In spring and summer, wind erosion climatic erosivity showed decreasing trends in whole of northern China from 1981-2016, whereas there was an increasing trend in wind erosion climatic erosivity over the Gobi Desert from 1992-2011. For the weather factor of the RWEQ model, the difference between northern Northwest China and the Gobi Desert and eastern-northern China was much larger than that of the wind erosion climatic erosivity of the WEQ model. In addition, in contrast to a decreasing trend in the weather factor of the RWEQ model over southern Northwest China during spring and summer from 1981-2016, the wind erosion climatic erosivity of the WEQ model showed a decreasing trend for 1981-1992 and an increasing trend for 1992-2011 over southern Northwest China. According to a comparison between dust emission and wind erosion climatic erosivity, the 2 models have the ability to project changes in future wind erosion in northern China.

Soil wind erosion evaluation and sustainable management of typical steppe in Inner Mongolia, China

Soil wind erosion is an important ecological environmental problem that is widespread in arid and semi-arid regions. Currently, related studies are mainly focused on spatiotemporal characteristics or analysis of effector mechanisms, and they do not facilitate direct servicing of management decisions. In this paper, we used the Xilingol typical steppe in Inner Mongolia, China, as a study site to develop a decision framework for a comprehensive understanding of soil wind erosion and to promote sustainable management of steppes. In this study, we used the Revised Wind Erosion Equation model to simulate soil wind erosion. We combined this model with linear trend analysis to evaluate the ecological effects of soil wind erosion and wind erosion intensity, and delineated the gravity center migration path. We used the constraint line method to reveal the mechanisms by which climatic factors affected soil wind erosion, achieved the spatial visualization of wind-breaking and sand-fixing service flow, and proposed decision-based regional sustainable development suggestions. The results showed that long-term soil wind erosion will lead to soil coarsening and loss of soil nutrients. Soil wind erosion in the study site showed worsening trends and risks, and as such, ecological environment conservation and management are urgently required. The study framework promotes a clear understanding of the complex relationship of human–earth systems. The study results will aid in the ecological remediation of steppe landscapes and the prevention of desertification and will provide a foundation for win–win management of ecological conservation and economic development in arid and semi-arid regions.

Wind Erosion Climate Change in Northern China During 1981\u20132016

Wind erosion is largely controlled by climate conditions. In this study, we examined the influences of changes in wind speed, soil wetness, snow cover, and vegetation cover related to climate change on wind erosion in northern China during 1981–2016. We used the wind erosion force, defined as wind factor in the Revised Wind Erosion Equation Model, to describe the effect of wind speed on wind erosion. The results show that wind erosion force presented a long-term decreasing trend in the southern Northwest, northern Northwest, and eastern northern China during 1981–2016. In the Gobi Desert, the wind erosion force presented for 1981–1992 a decreasing trend, for 1992–2012 an increasing trend, and thereafter a weakly decreasing trend. In comparison to wind speed, soil wetness and snow cover had weaker influences on wind erosion in northern China, while vegetation cover played a significant role in the decrease of wind erosion in the eastern northern China during 1982–2015.

Critical standing crop residue amounts for wind erosion control in the inland Pacific Northwest, USA

Crop residue is an important factor influencing wind erosion of cultivated soils. Establishing soil surface protection afforded by standing crop residue is critical for land managers seeking to reduce or prevent soil loss by wind erosion and the impacts of blowing dust from agricultural lands. The objectives of this study were to evaluate the effect of standing residue on soil wind erosion in the inland Pacific Northwest (iPNW), USA, and test the performance of the plant factor algorithm of the Agricultural Policy/Environmental eXtender (APEX) and Revised Wind Erosion Equation (RWEQ) models in influencing soil loss. The effect of standing winter wheat (Triticum aestivum L.), spring canola (Brassica napus L.), and chickpea (Cicer arietinum) residue on wind erosion, remaining from major commodity crops in the region, was tested in a laboratory wind tunnel using four levels of residue density. The impact of standing residue in controlling wind erosion was compared and analyzed in terms of residue density and their respective frontal area index. Our results show that residue at a density characteristic of the production environment (110 standing residue elements m−1 for winter wheat, 20 standing elements m−1 for canola, and 16 standing elements m−1 for chickpea) provided significant protection to the soil surface from wind erosion. Soil loss at this level of residue density was reduced by 73.3, 53.4, and 60.9% for respectively winter wheat, spring canola, and chickpea (frontal area indexes are 0.172, 0.104, and 0.026 respectively) compared with a surface without residue. The soil surface was found to be at significant risk from wind erosion when residue densities of the three crop types were <50% of the typical production amounts. Although not consistently significant, soil loss decreased as wind direction shifted from parallel to perpendicular with the standing residue row. The APEX model adequately simulated winter wheat and spring canola residue protection but had low accuracy in representing chickpea residue effects relative to the wind tunnel experiments. In contrast, the RWEQ model appeared inadequate in simulating soil loss for the winter wheat and canola treatments but adequately represented chickpea residue effects. Differences in model accuracy for different crop types must be considered by producers and managers to determine whether model information used to select practices to control wind erosion are likely to result in under- or over-protection of soil resources.

Impact of near-surface wind speed variability on wind erosion in the eastern agro-pastoral transitional zone of Northern China, 1982–2016

Wind erosion in arid and semi-arid areas is an important global environmental issue, and changes in wind speed trends over time play a key role in wind erosion dynamics. In a warming climate, scientists have recently observed a widespread decline in wind speed, termed “stilling”. Here, we apply the Revised Wind Erosion Equation Model (RWEQ) to simulate the variability of wind erosion and quantify the impact of wind speed changes on soil degradation dynamics over the eastern agro-pastoral transitional zone of Northern China from 1982 to 2016. Our results show that a significant (i.e., p < 0.05) decrease (-0.007 m s−1 year−1) of near-surface wind speed was observed annually, with significant declining trends in spring (-0.010 m s−1 year−1)and autumn (-0.009 m s−1 year−1). At the same time, wind erosion simulations reveal a negative trend for the annual soil loss from wind erosion (-6.20 t hectare-2 year -1, p < 0.05; affecting 99.8% of the study region), with significant declining trends in all seasons, particularly in spring (-3.49 t hectare-2 year−1) and autumn (-1.26 ha-2 year−1). Further, we isolate the effects of wind variability on wind erosion from 1982 to 2016 by the model variable control method. This shows that wind speed variability strongly weakens wind erosion at -8.14 t hectare-2 year -1 (p < 0.05) annually, with the strongest stilling recorded in spring leading to major decreases of wind erosion in spring (-4.77 t hectare-2 year−1, p < 0.05). Meanwhile, the weakest stilling in summer had the opposite influence on wind erosion (+0.40 t hectare-2 year -1, p < 0.10). To summarize, our findings have shown a significant impact of wind stilling on the decline of soil erosion rates in Northern China.

Assessment of wind-erosion risk in the watershed of the Ningxia-Inner Mongolia Reach of the Yellow River, northern China

Abstract The watershed of the Ningxia-Inner Mongolia Reach of the Yellow River (NIMRYR) suffers from serious wind-erosion hazard from several deserts distributed in this watershed. A mass of aeolian sediment is fed into the Yellow River directly or by its tributaries, which clogs the channel and causes major disasters in local regions. To prevent siltation of the Yellow River, it is urgent to understand the spatial variability and patterns of wind erosion in the NIMRYR watershed. For this purpose, the Integrated Wind-Erosion Modelling System (IWEMS) and the Revised Wind-Erosion Equation (RWEQ) were used to estimate the potential wind erosion rate (PWER) and to map wind-erosion risk in this watershed. In this study, the IWEMS model was used to calculate the PWER in non-arable lands, and the PWER in arable lands was estimated by the RWEQ model. The results show that the average PWER in the NIMRYR watershed ranged between 0 and 31440.4 t/km 2 /a from 2001 to 2010. The areas with tolerable erosion, slight erosion, moderate erosion, severe erosion, very severe erosion, and destructive erosion occupied 31.04%, 38.13%, 22.89%, 6.46%, 0.93%, and 0.55% of the total watershed area, respectively. The assessment results showed that sandy lands have the highest wind-erosion risk and that the risk in arable lands is lowest. The average annual quantity of aeolian sediment blown into the NIMRYR was 15.87 Mt between 2001 and 2010, and that blown into the Ten Tributaries was 7.33 Mt.

Dust Measurements in the Egyptian Northwest Coastal Zone

Standard dust sampling equipment was used to collect eroded aerosol samples from 52 wind erosion events in the Northwest Coastal Zone (NWCZ) of Egypt. The eroded samples were analyzed to determine the transport mass for each erosion event over a 3-year period from farm fields at Fuka and Abu Lahu. Weather, soil roughness, rock cover, and vegetative cover data were collected to provide input to the Revised Wind Erosion Equation (RWEQ) model to estimate transport mass. Annual rainfall in the NWCZ is much lower, soils have more surface stones, and crop planting and harvesting methods are much different from test sites in the U.S., where similar wind erosion studies on transport mass have been conducted. The soil at Fuka is 2.3 times more erodible by wind than the soil at Abu Lahu. Stone cover varied from 0% to 30% and 0% to 27%, and vegetative cover varied from 0% to 18% and 2% to 50% at Abu Lahu and Fuka, respectively. Soil ridge height was 0 to 10 cm and ridge spacing was 40 cm at both sites. Because of the large stones at Fuka and numerous round stones at Abu Lahu, a stone silhouette coefficient (Ssc) was developed in the Desert Research Institute at Cairo and used to estimate transport mass with RWEQ. Fifty-six percent and 62% of the erosion events in the NWCZ occurred in February, March, or April, and 59% and 83% of the events lasted between 11 to 20 h at Fuka and Abu Lahu, respectively. Maximum measured transport mass was 261.7 kg/m-width at Abu Lahu and 737.5 kg/m-width at Fuka. Maximum estimated transport mass with RWEQ was 285.9 kg/m-width at Abu Lahu and 649.8 kg/m-width at Fuka. The coefficient of determination was r2 = 0.93 for 60 clusters of measured and estimated transport mass at Fuka. For 44 clusters of measured and estimated transport mass at Abu Lahu, the coefficient of determination was r2 = 0.91. The RWEQ model with the stone silhouette coefficient can be used to describe wind erosion in the semi-arid Northwest Coastal Zone of Egypt. The RWEQ model can also be used to evaluate new management systems that utilize available resources to minimize wind erosion.