Erosion Area Research Articles

Flood-driven jet flow and sedimentary regime in a river-dominated estuary

Sediment dynamics under floods are critical for estuarine morphological evolution. A two-dimensional coupled hydrodynamic/sediment transport numerical modeling was adapted to investigate the flood-driven jet structure and the resultant sedimentary regime in a river-dominated estuary, Modaomen Estuary, Pearl River Delta, China. The results show that the flow velocity of flood jet exhibits a Gaussian distribution in the transverse direction and shows a linear decreasing trend in the longitudinal direction. Moreover, a distinct zonation, including a zone of flow establishment (ZOFE) and a zone of established flow (ZOEF), was detected. The ZOFE was the core area of high turbidity and strong erosion and provided sufficient sediments to the ZOEF, where sediment diffused and settled. Due to the settling lag, the sediment diffusion and deposition areas were larger than those of the jet. Estuarine geomorphology regulates the shape of flood jet, which shows an asymmetry configuration with the main body located at the west side of the bifurcated estuary. Tidal dynamics play a crucial role in altering the range of jet diffusion, especially in the longitudinal direction. Increased flood intensity has little effect on the jet structure and erosion/deposition pattern, but significantly increases the magnitude of seaward current velocities and bed level changes, as well as the transverse diffusion range of jet and sedimentation.

Diagnosis and Treatment of Recurrent Herpes Labialis: A Case Report

Introduction:Reactivation of herpes simplex virus (HSV)-1 can cause recurrent herpes labialis. This is a lesion that clinically consists of multiple vesicles that can break into erosive areas covered with crusts on the vermilion and surrounding skin. The lesions may recur, be triggered by systemic factors including; stress, menstruation, and local stimuli such as injury; sun exposure, and are usually preceded by prodromal symptoms. Case: a 44-year-old woman came to the Department of Oral Medicine at the Dental and Oral Hospital of the University of Jember with complaints of small blisters and peeling on the outer right corner of her mouth. The patient has had these complaints since 3 days, feels pain especially when eating and talking accompanied by not feeling well. The patient had experienced the same illness several years ago and relapsed again when experiencing stress and fatigue. The patient has no history of allergies, either to drugs or food. Treatment: Topical antiviral drugs are given in the form of 5% acyclovir cream and supportive therapy in the form of multivitamin tablets. Conclusion: Recurrent Herpes labialis caused by HSV-1 can be treated with topical antivirals drugs and multivitamin tablets.

Effects of soil conservation on the spatial heterogeneity of vegetation carbon sequestration in the Yellow River Basin, China

AbstractAn improved understanding of the potential controls on vegetation carbon sequestration (VCS) is essential for the prediction of VCS in response to global change. Ecosystem restoration can provide remarkable contributions to VCS. However, attention to the impact of soil conservation (SC) on VCS is lacking. Therefore, the Yellow River Basin, a typical area of soil erosion in the world, was chosen as the study area. The VCS and SC trends from 2000 to 2020 were analyzed and the potential response of VCS to SC was explored by adopting correlation analysis, elastic coefficient method, geographically weighted regression model, and geographical detector model. The influence of SC drivers on the spatial heterogeneity of VCS was also revealed. Results showed the following: (1) VCS and SC had a significant upward trend, especially in the eastern monsoonal ecoregion. (2) The area with a significant positive correlation between VCS and SC accounted for 31.74% of the total, mainly concentrated in the key areas of SC, wherein a 100% increase in SC would lead to a 25%–100% increase in VCS. (3) Among the SC drivers, vegetation cover and management (C) factor and rainfall erosion force (R) factor mainly influenced spatial heterogeneity in VCS, and their interaction considerably enhances this effect. Therefore, the interaction between precipitation and vegetation should be considered when evaluating the impact of water erosion management on VCS. The results of the study have important implications for the enhancement of VCS capacity of degraded land in the ecological restoration process.

Submarine canyon morphology along the Chilean marine forearc (19°S–45°S)

Convergent margins host more than half of all global submarine canyons. In this environment, the lack of cognition of the canyon morphology variation and their controls in two different types of marine forearcs (erosive and accretionary) remains exists. Based on shipborne bathymetric maps, we systematically analyze width, incision depth and slope gradient of 17 submarine canyons along the Chilean marine forearc. We divide the study area into an erosive northern area, a transitional central area, and an accretionary southern area based on trench sediment cover and in line with previous tectonic interpretations. In the northern and central areas, limited sediment supply and little erosion from infrequent turbidity currents form narrow and shallow canyons that arrive at the toe of margin. Subduction erosion contributes to a simple and regular slope morphology where regional subsidence and trench-parallel faulting activities lead to vertical crustal movement and a steep thalweg of canyons' lower reach. In contrast, frequent canyon flushing/filling turbidity currents and slope failures on the canyon walls result in a wider range of canyon width and incision depth in the south. Here, the formation of an accretionary prism generates fold and thrust ridges at the seafloor that reduce the slope gradient of canyons' lower reach. Canyon morphology within the prism region has a larger range than the non-prism (backstop) region due to the higher erodibility of the less consolidated sediment. In addition, convex-up step-shaped bedforms develop along 14 canyon thalwegs, also suggesting regional uplift/subsidence and normal faulting in the north and central region but folding and thrust faulting in the south. This work not only reveals the difference of canyon morphology on active marine forearcs but also may help to understand controls on submarine canyon morphologies along the Chilean margin as well as in other convergent margins.

A novel test method for characterizing tempo-spatial variations in elastic modulus of underwater concrete

Concrete structures used in underwater engineering, such as immersed tube tunnels, are subject to a range of challenging coupling circumstances including mechanical load (M), fluid flow (F), fluid pressure (P), and chemical attack (C). Concrete in different areas also experiences compressive or tensile stress under mechanical load. However, most experimental setups only consider limited coupling scenarios, such as M-C, M-F-C, or M-P-C, and the sample is typically in a single stress state, either compressive or tensile. To overcome these limitations, a novel stress-seepage-chemical coupling erosion setup (SSC-CES) was developed to perform durability tests on concrete. This setup allows for simulation of the service conditions of an immersed tube tunnel, including M-F-P-C coupling and distribution of compressive and tensile stresses. This study presents also a detailed description of the setup's components, configurations, and working principles, and discuss how sealing and alignment problems for the sample were addressed to ensure accurate fluid pressure and stress loading. The indentation technique was furthermore applied to obtain the local mechanical properties of different erosion areas, enabling analysis of tempo-spatial variations in elastic modulus. Finally, a test was conducted to examine the M-F-P-C coupling effect using the developed SSC-CES and indentation technique. Results indicated that the elastic modulus weakened from the erosion surface and gradually approached the initial value with increasing depth. Additionally, it showed a transition from slight increase to gradual decrease with erosion time. Notably, the elastic modulus in the tensile stress area was considerably lower than that in the compression stress area. These test results confirm the reliability of the developed SSC-CES and the rationality of the analysis method using micro-indentation technology. The system effectively supports the study of durability evaluation of immersed tube tunnels under M-F-P-C coupling.

The Influential Factors of the Habitat Quality of the Red-crowned Crane: A Case Study of Yancheng, Jiangsu Province, China

In order to effectively protect the habitat of cranes, this study constructs an indicator evaluation system based on the ecology–economy–society complex system and adopts the comprehensive “entropy weight method and analytic hierarchy process” evaluation model and coupled coordination model to scientifically measure the degree of coordinated development of the EES system in Yancheng. Further, a negative binomial regression model based on LASSO was used to analyze the key factors affecting the habitat quality of red-crowned cranes, and a support vector regression model was used to predict the population size of the cranes. The results show that the degree of the coordinated development of the EES system exhibited a fluctuating upward phenomenon, and the population size of the cranes also had a similar evolutionary trend, which indicates that the interaction between the two was significant and that the degree of the coordinated development of the system had a positive impact on the quality of the habitat of the cranes. Three types of ecological indicators (normalized difference vegetation index, annual precipitation, and soil erosion area) and three types of social indicators (natural growth rate, rural Engel coefficient, and public library collection) are the key factors affecting the population size of the cranes. The prediction results of the support vector regression model showed that the population of the cranes showed a fluctuating upward trend during the prediction interval, with a maximum of 952 cranes and an overall growth rate of 69.70%. The population size of the cranes is related to human social activities and the surrounding ecological environment, and the main reason for the decline in the population size of the cranes is the destruction of the local vegetation cover by the rapidly growing population and frequent human activities. Therefore, to improve the habitat quality of the cranes, local government departments need to strengthen the publicity of wildlife conservation, reduce agricultural land reclamation and pesticide pollution, and promote the coordinated development of the EES system in the Yancheng area.

Gas–solid two-phase erosion of multi-elbow relief line under supercritical condition

The Eulerian–Lagrangian method was used to establish a numerical model of a multi-elbow pipeline erosion and examine the erosion of the relief line elbow under supercritical conditions. The model was used to examine the effects of the discharge volume, sand content, and shape factor of sand on multi-elbow erosion and those of the connection length on double-elbow erosion. The erosion mechanism and law of multi-elbow lines under gas–solid two-phase flow conditions were revealed. The results indicated that the most severe erosion of the elbow occurred on the impact surface. However, the erosion area of the multi-elbow was relatively long. In a multi-elbow pipeline, the maximum erosion rate of the outlet elbow was 84 times that of the inlet elbow. For the multi-elbow pipeline, the erosion rate was related to the discharge volume, sand content, particle shape, and length of the connection between elbows. The erosion rate of the elbow at the outlet decreased gradually and stabilized with an increase in the connection length.

Significant efficacy of short-course, low-concentration betamethasone mouthwash therapy for severe erosive oral lichen planus: a randomized controlled trial.

To evaluate the short-term efficacy of low-concentration betamethasone mouthwash for severe erosive oral lichen planus (EOLP). In this randomized, investigator-blind, positive-controlled trial, OLP patients with erosive lesions received betamethasone mouthwash (0.137 mg/mL) or dexamethasone mouthwash (0.181 mg/mL) three times daily for 2 or 4 weeks and were followed up for 3 months to observe recurrence. The primary outcome was the week-2 reduction in erosive area. Fifty-seven participants were randomized to betamethasone (n = 29) and dexamethasone (n = 28). At week 2, participants using betamethasone (n = 28) experienced a greater reduction in erosive area than gargling with dexamethasone (n = 26). Similarly, secondary outcomes, including the healing proportion of erosions, reduced pain level, reduction in atrophic area, Thongprasom score, and recurrence interval, showed the superiority of betamethasone. At week 4, betamethasone (n = 7) was not superior to dexamethasone (n = 15) in further reducing lesional area and pain level. No serious adverse events were documented. The 0.137 mg/mL compound betamethasone mouthwash exhibited significant efficacy in rapidly enhancing erosion healing within 2 weeks and extending the recurrence interval with a good safety profile. This study proved the significant efficacy of short-course 0.137 mg/mL betamethasone mouthwash therapy for treating erosion and pain, providing a novel topical agent for patients with severe EOLP. This study was prospectively registered at the International Clinical Trials Registry Platform ( ChiCTR1800016507 ) on 5 June 2018.

Influence of Pressure on the PD and Induced Aging Behavior of Polyimide Insulation Under Repetitive Pulse Voltage

Reduction of air pressure can influence insulation material’s behavior with respect to resisting partial discharge (PD) generation and its induced aging process. This may bring threat to the insulation reliability of medium frequency transformers working under low pressure condition, considering they are exposed to high probability of PD inception caused by PWM voltage. Aiming at investigating the performance of insulation of medium frequency transformer being operated in an environment with a decreasing pressure, this paper introduces a test system that can conduct partial discharge and endurance lifetime tests under repetitive pulse voltage and controlled pressure. Using this test system and focusing on polyimide film, which is one of the main insulation materials used by medium frequency transformers, partial discharge and endurance lifetime tests are conducted under different pressures. The results show that partial discharge inception voltage decreases with decreasing pressure. However, the changing of partial discharge magnitude, time lag and its induced insulation lifetime do not change monotonously. Surface of the failed insulation samples show that the erosion area caused by partial discharge is larger under lower pressure. The mechanisms behind the changing of partial discharge time lag, discharge magnitude, endurance lifetime, along with the discharge eroded area with pressure are discussed in detail.

Synergistic soil, land use, and climate influences on wind erosion on the Colorado Plateau: Implications for management

Two decades of drought in the southwestern USA are spurring concerns about increases in wind erosion, dust emissions, and associated impacts on ecosystems, agriculture, human health, and water supply. Different avenues of investigation into primary drivers of wind erosion and dust have yielded mixed results depending on the spatial and temporal sensitivity of the evidence. We monitored passive aeolian sediment traps from 2017 to 2020 across eighty-one sites near Moab, Utah to understand patterns of sediment flux. At measurement sites, we collated climate, soil, topography and vegetation spatial layers to better understand the context of wind erosion and then combined these data with field observations of land use in models to characterize the influence of cattle grazing, oil and gas well pads, and vehicle/heavy equipment disturbance that potentially drive both exposure of bare soil and increases in erodible sediment supply that increase vulnerability to erosion. Disturbed areas with low soil calcium carbonate content yielded high sediment transport in dry years, but notably areas with little disturbance and low bare soil exposure had much less activity. Cattle grazing had the largest land use association with erosional activity with analyses suggesting that both herbivory and trampling from cattle could be drivers. The amount and distribution of bare soil exposure from new sub-annual fractional cover remote sensing products proved very helpful in mapping erosion, and new predictive maps informed by field data are presented to help depict spatial patterns of wind erosion activity. Our results suggest that despite the magnitude of current droughts, minimizing surface disturbance in vulnerable soils can mitigate a large portion of dust emissions. Results can help land managers identify eroding areas where disturbance reduction and soil surface protection measures can be prioritized.

Morphological Evolution and Sedimentological Study of the Essaouira Bay and the Mouth of Oued Ksob, Essaouira, Morocco

The coastline of Essaouira is located on the Atlantic coast of Morocco. The Bay of this city is a large sandy system strongly marked by coastal and fluvial dynamics, which makes it a perfect example of sedimentology processes in a Bay area. using of satellite imagery allows us to determine the morphological evolution of the Essaouira Bay and the mouth of Oued Ksob. The results of the study show the evolution of the coastline of the Essaouira Bay with areas of erosion and others in accumulation. The analysis of satellite images allows us to distinguish three very different sectors: the first is north of the estuary of Oued Ksob, this area receives most of the flood contributions of Oued Ksob, which helps to maintain its morpho-sedimentary balance. The second sector, which is composed of the estuary and the mouth of the Oued Ksob, is characterized by a hydrodynamic both fluvial and maritime. The third sector is located south of the estuary of Oued Ksob, which is not affected by the effect of the presence of the obstacle on the island of Mogador. The sedimentological study is carried out in four different areas, which are: the dunes, the mouth of Oued Ksob, which has undergone numerous recorded positions since the late 19th century, the area south of the estuary, and the area north of the mouth. Several analyses were carried out namely: granulometry, morphoscopy, calcimetry, and X-ray diffraction, which confirmed that the origin of the studied sediments is both continental and marine.

Environmental Threat of Soil Erosion in the Gwang Khola Watershed, Chure Region of Nepal

Chure, also known as the foothills of the Himalayas that extends from east to west of Nepal, is an essential region due to the hotspot of biological diversity and various natural resources, including recharge groundwater for the Tarai region of the country. However, the Chure region has a high rate of soil erosion due to human activities and natural processes, a severe issue in the Chure region. This study looked at soil erosion in the Gwang Khola watershed in the Chure region. We used the Revised Universal Soil Loss Equation (RUSLE) model to measure soil loss by soil erosion. The results showed that about 547,992.9 tons of soil were lost annually in the Gwang Khola watershed. The results indicated that 5,259.87 hectares of the land area were in a very low-risk zone for soil erosion. Similarly, 317.79 hectares of land had a moderate risk of soil degradation, while 13.59 hectares of forest area posed a high threat. The extreme-risk erosion area was situated above 1,250 m. In contrast, the moderate and the low-risk regions of soil erosion had a lower elevation range of 950 m to 1,250 m and 650 m to 950 m, respectively. The findings of this study may aid planners and policymakers in preventing soil erosion and protecting the ecosystem in this watershed and those with similar circumstances.

Head-cut gully erosion susceptibility mapping in semi-arid region using machine learning methods: insight from the high atlas, Morocco

Gully erosion has been identified in recent decades as a global threat to people and property. This problem also affects the socioeconomic stability of societies and therefore limits their sustainable development, as it impacts a nonrenewable resource on a human scale, namely, soil. The focus of this study is to evaluate the prediction performance of four machine learning (ML) models: Logistic Regression (LR), classification and regression tree (CART), Linear Discriminate Analysis (LDA), and the k-Nearest Neighbors (kNN), which are novel approaches in gully erosion modeling research, particularly in semi-arid regions with a mountainous character. 204 samples of erosion areas and 204 samples of non-erosion areas were collected through field surveys and high-resolution satellite images, and 17 significant factors were considered. The dataset cells of samples (70% for training and 30% for testing) were randomly prepared to assess the robustness of the different models. The functional relevance between soil erosion and effective factors was computed using the ML models. The ML models were evaluated using different metrics, including accuracy, the kappa coefficient. kNN is the ideal model for this study. The value of the AUC from ROC considering the testing datasets of KNN is 0.93; the remaining models are associated to ideal AUC and are similar to kNN in terms of values. The AUC values from ROC of GLM, LDA, and CART for testing datasets are 0.90, 0.91, and 0.84, respectively. The value of accuracy considering the validation datasets of LDA, CART, KNN, and GLM are 0.85, 0.82, 0.89, 0.84 respectively. The values of Kappa of LDA, CART, and GLM for testing datasets are 0.70, 0.65, and 0.68, respectively. ML models, in particular KNN, GLM, and LDA, have achieved outstanding results in terms of creating soil erosion susceptibility maps. The maps created with the most reliable models could be a useful tool for sustainable management, watershed conservation and prevention of soil and water losses.

Causes and Measures of Soil Erosion in Loess Plateau, China

Soil erosion is one of the key research topics in the world today, and it is a serious hazard to the natural environment and economic and social development. The researcher has found that soil erosion in China is regional, widespread and high-intensity. Of all the erosion areas, the Loess plateau is the most severe and the most representative. Therefore, this paper investigates the current situation of soil erosion in China and focuses on the erosion on the Loess Plateau, for its causes and remediation measures. Loess plateau has an inferior erosion-carrying capability, so the gully slopes and hilly areas of the Loess Plateau are prone to landslides and crumbling phenomena. Other erosion reasons include the fragmented high loess terrain with a lot of gorges and ravines, heavy rainfall, and low vegetation coverage. This study also proposes remediation measures by analyzing the different natural characteristics that cause soil erosion on the Loess Plateau. It is found that soil erosion control has a regional dimension and control measures should be closely related to the regional environment and the causes of soil erosion. Practice shows that the erosion control measures proposed in this paper greatly improve erosion in the Loess Plateau region, but the current state of soil erosion on the Loess plateau remains bleak.

Gateway to the arctic: Defining the eastern channel of the Bering Strait

The Bering Strait is the sole gateway and an oceanographic bottleneck for the seasonally warm and comparatively fresh and nutrient-rich Pacific waters to flow into the Arctic, melting ice, lowering salinity, and feeding bird, mammal, and fish populations. The Diomede Islands split this small strait into two main channels, both with northward flow (in the annual mean). The eastern channel, in U.S. waters, also seasonally carries the warmer, fresher Alaskan Coastal Current. Year-round in situ mooring observations (in place since 1990 with annual servicing) show a significant flow increase in the (northward) throughflow, along with seasonal and annual fluctuations. To help with measuring and modelling water flow estimates, we created the first detailed shore-to-shore bathymetric surface of the Bering Strait’s eastern channel, located its narrowest cross-section (1.8 km2) as occurring 5–10 km south of the moorings, and quantified the cross-section across the moorings (2.0 km2), both slightly larger than previously estimated (1.6 km2). Overlaps between older (∼1950) and newer (∼2010) bathymetry data sets identified clear areas of erosion and deposition, with much of the eastern channel having eroded by > 1 m. Since the depth is uniformly ∼ 50 m across much of the eastern channel, the 1 m of erosion that we quantified would only slightly (2 %) increase the sizes of the cross-sections. Much of the seafloor is hard substrate and probably composed of cobbles, but we hypothesize that friction from strong (∼1 + knot) seafloor currents is the most likely explanation for the erosion that we observed. In softer and siltier areas, the bathymetry showed additional evidence of potential current impacts in the form of small seafloor waves (∼0.5 to ∼ 1.0 m tall) and a shore-parallel bar offshore of Cape Prince of Wales Spit. There are large (∼2 m tall) seafloor waves seaward of Cape Prince of Wales Shoal. A previously undescribed (∼1 to 2 km wide, ∼4 m deep) seafloor channel of unknown origin occurred along a linear north/south axis for the full 75 km extent of the bathymetric surface. The southern end of this seafloor channel was near the end of three larger seafloor channels extending westerly out of nearby Norton Sound, suggesting a common origin. These Norton Sound channels may be paleodrainages, as their eastern ends point toward Seward Peninsula inlets with large drainages where paleoglaciers were reported to have existed, but the morphology of these channels is also consistent with tidal channels.

Water erosion changes on the Qinghai-Tibet Plateau and its response to climate variability and human activities during 1982–2015

Climate variability and human activities cause changes in precipitation and underlying surface conditions, which are the main driving forces of changes in water erosion, especially in the Qinghai-Tibet Plateau (QTP). In this paper, the water erosion on the QTP from 1982 to 2015 was quantified by the Revised Universal Soil Loss Equation (RUSLE), and the response of water erosion changes to climate variability and human activities was investigated. The results indicated that the distribution of water erosion gradually decreased from south to north during 1982–2015. Areas of severe erosion were mainly distributed along the Yarlung Tsangpo River and in the western Hengduan Mountains. The years of the abrupt change in water erosion were 1989 and 2006. Compared to 1982–1989, the amount of water erosion was mitigated in both 1990–2006 and 2007–2015, with a 19.5% and 6.2% decrease, respectively. The contribution of human activities to the decrease in water erosion was 25.4% and 16.7% for each of these periods, respectively, and the contribution of climate variability to the increase in water erosion was 5.9% and 10.5%. However, water erosion increased by 16.5% from 2007 to 2015 compared to 1990–2006. The contribution of climate variability was 4.9% and the contribution of human activities 8.4%. The increase in water erosion due to human activities may be attributed to the construction of the Qinghai-Tibet Railway and associated human activities. It is therefore important to draw attention to the influence of human activities on the QTP on erosion, to prevent potential future risks. This study is the first attempt to research the relative contributions of variation in climate and human activities to changes in water erosion on the QTP. It would be beneficial for carrying out ecological environmental protection work on the QTP.

River blockage and impulse wave evolution of the Baige landslide in October 2018: Insights from coupled DEM-CFD analyses

On 11 October 2018, the Baige landslide in Southwest China blocked the Jinsha River and induced waves amplifying the landslide-affected area significantly. Devastating flood damage was caused by the consequent dam breach. Such a complex sequence can lead to catastrophic consequences but has rarely been fully reproduced. This paper investigates the landslide-river interaction of the first Baige landslide based on coupled discrete element method (DEM) and computational fluid dynamics (CFD) analyses. To this end, the volume of fluid (VOF) and virtual sphere model are adopted to realise impacted river tracing and accurate terrain modelling. The damming process and impulse wave evolution of the first event are well represented. In addition, the simulated cumulative landslide spreading path, deposit geometry, maximum wave elevation and cumulative wave erosion area satisfactorily match the survey results. Our findings further indicate that the movement path and deposit morphology of the Baige landslide are mainly affected by local terrain, while the propagation of impulse waves is driven by the sliding mass and modulated by the riverbank and hydrodynamic conditions. In particular, we discussed the evolution patterns of impulse waves caused by river damming landslides, encompassing run-up on the opposite bank and quasi-3D propagation along the river direction. This research provides a valuable guide for the practical simulation of river blockage and impulse wave evolution and supports the mitigation of landslide disasters in mountainous areas.

Estimating the Soil Erosion Response to Land-Use Change Using GIS-Based RUSLE and Remote Sensing: A Case Study of Heilongjiang Province, China

Understanding soil erosion in the northeastern area of China with black soil is vital for protecting the natural environment and preserving food security. Although spatial and temporal studies of soil erosion have been conducted, further research is needed on the correlation between soil erosion and land use type changes. In this study, the soil erosion modulus is computed using RUSLE. The model that is most suitable to the research area was produced by contrasting three different approaches to estimating the rainfall erosion factor. The RUSLE based on the multi-year continuous high-density hourly average precipitation had the best performance of the bunch, with a MAPE of 15.49%, RMSPE of 7.99%, and R2 of 0.99. Based on this model, simulated soil erosion trends in the study region from 1980 to 2020 were examined, along with the link between soil erosion and land use change. The results showed that 40.47% of the overall erosion area is made up of cultivated land, and 97.83% of it is low erosion. The most severe soil erosion occurred on unused land, with moderate and above soil erosion occupying 48.93%. Since 2000, there has been an increase in the erosion of soil in the study region, which is primarily spatially represented in the rise in the soil erosion of forests in the central and northern mountainous areas. The study’s findings serve as a guide for land planning and the development of sustainable agriculture.

Establishment of a minimum dataset and soil quality assessment for multiple reclaimed areas on a wind-eroded region

About 60 years ago, overgrazing, of severe wind erosion in Konya-Karapınar region, which is in an arid semi-arid ecosystem. In this context, an effective fight against desertification was carried out with different land management practices for erosion control. The aim of this study is to establish a minimum dataset of soil properties determine the impact of different land uses on the soil quality index (SQI). Therefore, soil properties of five different land use types [i.e.(Forested land (FL), Grazing land (GL), Cultivated land (CL), Apple orchard (AO) and Erosive area (EA))] in the wind erosion affected area were evaluated. In the study, a total of 264 disturbed and undisturbed samples were taken from three different depths (0–10, 10–20 and 20–40 cm). On these samples, Physical [field capacity (FC), wilting point (WP), bulk density, Aggregate Stability (AS), Penetration Resistance (PR)], chemical [pH, Electrical Conductivity (EC), Lime (L), Total Nitrogen (TN), Available P (AP), Ca, Mg, Na, K, exchangeable Fe, Cu, Mn, Zn Cation exchange capacity (CEC), Exchangeable sodium percentage (ESP)], and biological [Organic Carbon (OC), Active Carbon (AC), Potential Mineralizable Nitrogen (PMN), Respiration (S)] analyses were carried out. According to principal component analysis, FC, AS, ESP, CEC, AP, OC, R were selected indicators. Scoring functions of the selected indicators were created and each indicator was scored separately. Accordingly, for 0–40 cm soil depth, SQI was calculated as EA 0.10, FL 0.38, GL 0.45, CL 0.67 and AO 0.70. There have been significant improvements in soil quality compared to the EA, however, the amount of improvement has been more limited in graze and forest lands. It has been suggested that the selected indicators should be considered as the change-sensitive properties of the soils in the study area and similar areas, and that more areas should be allocated for horticulture in erosion protection areas.

Comparison and quantitative assessment of two regional soil erosion survey approaches

Regional soil erosion surveys are the first step of soil conservation planning. Grid and sampling approaches are commonly used for soil erosion surveys at the regional scale. With the grid approach, the region is divided into grids (e.g., 1 km × 1 km), and the soil erosion rate of each grid was calculated. With the sampling approach, a small portion of the area (typically 4% or less) was taken and then the soil erosion rate was calculated. Based on the above calculation, both approaches evaluated the soil erosion area (which is the area where the soil erosion rate is greater than the soil loss tolerance (t)) and its distribution in the whole region. The purpose of this paper is to compare the assessment results of the two approaches and analyse their practicality using Yunyang County, Chongqing, China (area is 3636 km2). The soil erosion rate, percentage of soil erosion area (PSEA, which is the ratio of the area where the soil erosion rate is greater than the soil loss tolerance (t) to the area of the total study region) and its spatial distribution were compared between the two approaches. The results showed that the grid approach overestimated the average soil erosion rate and PSEA overall for all 33 sample units and the whole region in comparison to the sampling approach. The sampling approach can yield a reasonable spatial distribution of the soil erosion rate in the whole region. In addition, the soil erosion regions were more clustered than those using the grid approach, which can be more suitable for soil conservation planning. Therefore, the sampling approach is an efficient and practical approach in regional soil erosion surveys. The results can provide insights into regional soil erosion surveys.