Erosion Sensitivity Research Articles

Gully Erosion Susceptibility Mapping Using Multivariate Adaptive Regression Splines—Replications and Sample Size Scenarios

Soil erosion is a serious problem affecting numerous countries, especially, gully erosion. In the current research, GIS techniques and MARS (Multivariate Adaptive Regression Splines) algorithm were considered to evaluate gully erosion susceptibility mapping among others. The study was conducted in a specific section of the Gorganroud Watershed in Golestan Province (Northern Iran), covering 2142.64 km2 which is intensely influenced by gully erosion. First, Google Earth images, field surveys, and national reports were used to provide a gully-hedcut evaluation map consisting of 307 gully-hedcut points. Eighteen gully erosion conditioning factors including significant geoenvironmental and morphometric variables were selected as predictors. To model sensitivity of gully erosion, Multivariate Adaptive Regression Splines (MARS) was used while the Area Under the Receiver Operating Characteristic (ROC) Curve (AUC), drawing ROC curves, efficiency percent, Yuden index, and kappa were used to evaluate model efficiency. We used two different scenarios of the combination of the number of replications, and sample size, including 90%/10% and 80%/20% with 10 replications, and 70%/30% with five, 10, and 15 replications for preparing gully erosion susceptibility mapping (GESM). Each one involves a various subset of both positive (presence), and negative (absence) cases. Absences were extracted as randomly distributed individual cells. Therefore, the predictive competency of the gully erosion susceptibility model and the robustness of the procedure were evaluated through these datasets. Results did not show considerable variation in the accuracy of the model, with altering the percentage of calibration to validation samples and number of model replications. Given the accuracy, the MARS algorithm performed excellently in predictive performance. The combination of 80%/20% using all statistical measures including SST (0.88), SPF (0.83), E (0.79), Kappa (0.58), Robustness (0.01), and AUC (0.84) had the highest performance compared to the other combinations. Consequently, it was found that the performance of MARS for modelling gully erosion susceptibility is quite consistent while changes in the testing and validation specimens are executed. The intense acceptable prediction capability of the MARS model verifies the reliability of the method employed for use of this model elsewhere and gully erosion studies since they are qualified to quickly generating precise and exact GESMs (gully erosion sensitivity maps) to make decisions and management edaphic and hydrologic features.

A Comparative Assessment of Random Forest and k-Nearest Neighbor Classifiers for Gully Erosion Susceptibility Mapping

This research was conducted to determine which areas in the Robat Turk watershed in Iran are sensitive to gully erosion, and to define the relationship between gully erosion and geo-environmental factors by two data mining techniques, namely, Random Forest (RF) and k-Nearest Neighbors (KNN). First, 242 gully locations we determined in field surveys and mapped in ArcGIS software. Then, twelve gully-related conditioning factors were selected. Our results showed that, for both the RF and KNN models, altitude, distance to roads, and distance from the river had the highest influence upon gully erosion sensitivity. We assessed the gully erosion susceptibility maps using the Receiver Operating Characteristic (ROC) curve. Validation results showed that the RF and KNN models had Area Under the Curve (AUC) 87.4 and 80.9%, respectively. As a result, the RF method has better performance compared with the KNN method for mapping gully erosion susceptibility. Rainfall, altitude, and distance from a river were identified as the most important factors affecting gully erosion in this area. The methodology used in this research is transferable to other regions to determine which areas are prone to gully erosion and to explicitly delineate high-risk zones within these areas.

Establishing an ecological security pattern for urban agglomeration, taking ecosystem services and human interference factors into consideration.

The assessment of ecological security patterns is a topic of conversation in landscape ecology in recent years. However, ecosystem services and human activities are seldom considered comprehensively in the assessment of ecological security patterns. The present study employs the Beijing–Tianjin–Hebei urban agglomeration as a study area, and uses ecological services to determine the ecological sources. The importance of ecological sources is classified based on logical coding and functional types of ecological services. The research combines regional characteristics to select and quantitatively calculate three human disturbance factors: soil erosion sensitivity, geological hazard sensitivity, and night lighting. Then the basic surface resistance of land use to limit migration is modified and ecological corridors are identified by combining these three disturbance factors. The results indicate that the sources of water production, soil and water conservation, and carbon fixation are mainly provided in mountainous areas, recreation sources are mostly distributed in the plains, and these ecological sources improve the maintenance of ecological corridors. The modification of resistance surfaces significantly changes the length of ecological corridors in Tianjin, Tangshan, Cangzhou, and Beijing, and the modified resistance surface improves the recognition of ecological corridors. This study provides a new research framework for identifying the ecological security patterns of urban agglomerations and provides scientific guidance related to ecological protection and urban planning for the Beijing−Tianjin−Hebei urban agglomeration.

GIS-Based MCDA Model to Assess Erosion Sensitivity in Gumara watershed, Blue Nile, Basin Ethiopia

GIS-Based MCDA Model to Assess Erosion Sensitivity in Gumara watershed, Blue Nile, Basin Ethiopia

Estimation of Soil Losses in a Slope Area of Tokat Province through USLE and WEPP Model

Tokat is one of the developing provinces in terms of urbanism. Therefore, the land use changes city-wide which closely affects soil erosion. Numerical estimation of soil erosion is very important to prevent soil losses. In this study, USLE and WEPP Hillslope model were used to estimate the long-term soil losses in a slope area which used to be a pasture land and then turned into a fruit orchard in Büyükbeybağı area of Tokat province. Erosion sensitivity of the soil in the slope area was detected to be very low. Erosivity value of the area is low, soil is resistant to erosion due to pasture land use type and fruit orchard use type does not require intense soil cultivation practices. For all these reasons, both estimation technologies estimated soil losses of the land to be low.

Quantitative Analysis of Cartilage Invasion by Laryngeal Carcinoma with Dual-Energy CT Iodine Overlay Images and Spectrum Curve

Background: Laryngeal cancer stage is essential for determining the appropriate treatment strategies and evaluating prognosis for laryngeal carcinoma, which is based primarily on laryngeal cartilage invasion or not. However, there was no optimal means to confirm whether cartilage was being invaded before operation. With dual-energy CT development, it provided a new potential approach for laryngeal cartilage invasion diagnosis. Objectives: To evaluate the clinical value of dual-energy computed tomography with iodine overlay images and spectrum curve in the quantitative analysis of laryngeal cartilage invasion in patients with laryngeal carcinoma. Patients and Methods: Dual-source dual-energy CT was performed for one hundred and twenty patients with confirmed diagnosis of laryngeal carcinoma by surgical pathology (56 cases with laryngeal cartilage invasion and 64 cases without invasion). The mean CT attenuation values of laryngeal cartilage and the tumor in routine scan, arterial and venous phases was measured and cartilage invasion was considered to be present with asymmetric sclerotic changes, erosion, lysis and extralaryngeal tumor spread with iodine overlay images and routine scan images. Moreover, the sensitivity and specificity were analyzed. The slope of spectral curve and iodine concentration of the tumors, invaded laryngeal cartilage and non-invaded laryngeal cartilage were compared between arterial phase and venous phase. Furthermore, the receiver operating characteristic (ROC) curve of mean CT attenuation value, the slope of spectral curve and iodine concentration were made comparative analysis. Results: The mean CT attenuation values of the tumors, invaded laryngeal cartilage and non-invaded laryngeal cartilage had significant difference among the routine scan, arterial phase and venous phase (P < 0.05). The sign of asymmetric sclerotic changes had no significant difference between iodine overlay images and routine scan images (the same specificity and sensitivity, 77.8% and 52.6%, respectively). However, the signs of erosion, lysis and extralaryngeal tumor spread had significant difference. The specificity and sensitivity of iodine overlay images were superior to that of the routine scan images in the three signs (specificity and sensitivity of erosion: 92.3% vs. 61.5%, and 86.7% vs. 60.0%, respectively; lysis: 82.4% vs. 69.2%, and 81.8% vs. 66.7%, respectively; extralaryngeal tumor spread: 90.9% vs. 68.3%, and 100% vs. 63.5% respectively). The slope of spectral curve and iodine concentration of the tumors, invaded laryngeal cartilage and non-invaded laryngeal cartilage showed significant difference (P < 0.05). The iodine concentration of the tumor was higher than invaded laryngeal cartilage. The area under the curve (AUC) value of mean CT attenuation value in routine scan, arterial phase and venous phase were 0.064, 0.265, and 0.192, respectively. The AUC value of the slope of spectral curve in arterial phase was 0.970 and its selected cutoff was considered as 1.09. In this cutoff point, the diagnostic indices including sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 88.9%, 100%, 100%, and 82.6%, respectively, while the AUC value of the slope of spectral curve in venous phase was 0.944 and its selected cutoff was considered as 0.95. In this cutoff point, the diagnostic indices including sensitivity, specificity, PPV, NPV, positive likelihood ratio (PLR), negative likelihood ration (NLR) were 81.5%, 96.3%, 91.7%, 77.3%, 7.76, and 19.30, respectively. The AUC value of the slope of iodine concentration in arterial phase was 0.995 and its selected cutoff was considered as 1.05. In this cutoff point, the diagnostic indices including sensitivity, specificity, PPV and NPV were 92.6%, 100%, 95.8%, and 100%, respectively. Moreover, the AUC value of the slope of iodine concentration in venous phase was 0.905 and its selected cutoff was considered as 0.75. In this cutoff point, the diagnostic indices including sensitivity, specificity, PPV, NPV, PLR, and NLR were 77.8%, 88.9%, 91.3%, 82.6%, 7.00, and 24.5, respectively. Conclusion: Dual-energy CT can provided a new potential approach for laryngeal cartilage invasion diagnosis in order to guide the selection of optimal operation plan and improve the prognosis.

Penetapan Kelas Kemampuan Lahan Dan Arahan Rehabilitasi Lahan Das Wai Batu Merah Kota Ambon Provinsi Maluku

Land use planning requires a proper consideration, so that the function of land can take place continuously and sustainably. The objectives of the research were to establish the land capability class of Wai Batu Merah watershed its land use management in accordance with each land capability class. The research method was survey with synthetic and analytical approaches, and flexible observation distance following physiographic change, soil type and land use within landunits. The results of the study showed that Wai Batu Merah watershed has 6 class and 12 sub-class land capability of II.B,KE3,e1, III.e2, III.C, IV.b2, IV.D,b2, IV.D, VI.e4, VI.E, VII.e5, VII.F,e5, VII.F, and VIII.t5 with limiting factors of slope steepness, erosion sensitivity, percentage of gravel and rock, and soil texture. Land use management planning in the Wai Batu Merah watershed includes intensive, medium, and limited agriculture, intermediate and limited grazing, agroforestry, protection forest, forest, home garden, biopores and organic materials.Keywords: Land Capability Class, Wai Batu Merah Watershed

Soil erodibility mapping using the RUSLE model to prioritize erosion control in the Wadi Sahouat basin, North-West of Algeria.

Soil losses must be quantified over watersheds in order to set up protection measures against erosion. The main objective of this paper is to quantify and to map soil losses in the Wadi Sahouat basin (2140km2) in the north-west of Algeria, using the Revised Universal Soil Loss Equation (RUSLE) model assisted by a Geographic Information System (GIS) and remote sensing. The Model Builder of the GIS allowed the automation of the different operations for establishing thematic layers of the model parameters: the erosivity factor (R), the erodibility factor (K), the topographic factor (LS), the crop management factor (C), and the conservation support practice factor (P). The average annual soil loss rate in the Wadi Sahouat basin ranges from 0 to 255tha-1year-1, maximum values being observed over steep slopes of more than 25% and between 600 and 1000m elevations. 3.4% of the basin is classified as highly susceptible to erosion, 4.9% with a medium risk, and 91.6% at a low risk. Google Earth reveals a clear conformity with the degree of zones to erosion sensitivity. Based on the soil loss map, 32 sub-basins were classified into three categories by priority of intervention: high, moderate, and low. This priority is available to sustain a management plan against sediment filling of the Ouizert dam at the basin outlet. The method enhancing the RUSLE model and confrontation with Google Earth can be easily adapted to other watersheds.

The role of beach morphology on coastal cliff erosion under extreme waves

AbstractErosion of hard‐rock coastal cliffs is understood to be caused by a combination of both marine and sub‐aerial processes. Beach morphology, tidal elevation and significant wave heights, especially under extreme storm conditions, can lead to variability in wave energy flux to the cliff‐toe. Wave and water level measurements in the nearshore under energetic conditions are difficult to obtain and in situ observations are rare. Here we use monthly cliff‐face volume changes detected using terrestrial laser scanning alongside beach morphological changes and modelled nearshore hydrodynamics to examine how exposed cliffs respond to changes in extreme wave conditions and beach morphology. The measurements cover the North Atlantic storms of 2013 to 2014 and consider two exposed stretches of coastline (Porthleven and Godrevy, UK) with contrasting beach morphology fronting the cliffs; a flat dissipative sandy beach at Godrevy and a steep reflective gravel beach at Porthleven. Beach slope and the elevation of the beach–cliff junction were found to influence the frequency of cliff inundation and the power of wave–cliff impacts. Numerical modelling (XBeach‐G) showed that under highly energetic wave conditions, i.e. those that occurred in the North Atlantic during winter 2013–2014, with Hs = 5.5 m (dissipative site) and 8 m (reflective site), the combination of greater wave height and steeper beach at the reflective site led to amplified wave run‐up, subjecting these cliffs to waves over four times as powerful as those impacting the cliffs at the dissipative site (39 kWm‐1 compared with 9 kWm‐1). This study highlighted the sensitivity of cliff erosion to extreme wave conditions, where the majority (over 90% of the annual value) of cliff‐face erosion ensued during the winter. The significance of these short‐term erosion rates in the context of long‐term retreat illustrates the importance of incorporating short‐term beach and wave dynamics into geomorphological studies of coastal cliff change. © 2017 The Authors. Earth Surface Processes and Landforms published by John Wiley &amp; Sons Ltd.

Application of fuzzy logic approach for wind erosion hazard mapping in Laghouat region (Algeria) using remote sensing and GIS

Abstract Wind erosion is one of the most serious environmental problems in Algeria that threatens human activities and socio-economic development. The main goal of this study is to apply a fuzzy logic approach to wind erosion sensitivity mapping in the Laghouat region, Algeria. Six causative factors, obtained by applying fuzzy membership functions to each used parameter, are considered: soil, vegetation cover, wind factor, soil dryness, land topography and land cover sensitivity. Different fuzzy operators (AND, OR, SUM, PRODUCT, and GAMMA) are applied to generate wind-erosion hazard map. Success rate curves reveal that the fuzzy gamma (γ) operator, with γ equal to 0.9, gives the best prediction accuracy with an area under curve of 85.2%. The resulting wind-erosion sensitivity map delineates the area into different zones of five relative sensitivity classes: very high, high, moderate, low and very low. The estimated result was verified by field measurements and the high statistically significant value of a chi-square test.

Second-Pass Assessment of Potential Exposure to Shoreline Change in New South Wales, Australia, Using a Sediment Compartments Framework

The impacts of coastal erosion are expected to increase through the present century, and beyond, as accelerating global mean sea-level rise begins to enhance or dominate local shoreline dynamics. In many cases, beach (and shoreline) response to sea-level rise will not be limited to passive inundation, but may be amplified or moderated by sediment redistribution between the beach and the broader coastal sedimentary system. We describe a simple and scalable approach for estimating the potential for beach erosion and shoreline change on wave-dominated sandy beaches, using a coastal sediment compartments framework to parameterise the geomorphology and connectivity of sediment-sharing coastal systems. We apply the approach at regional and local scales in order to demonstrate the sensitivity of forecasts to the available data. The regional-scale application estimates potential present and future asset exposure to coastal erosion in New South Wales, Australia. The assessment suggests that shoreline recession due to sea-level rise could drive a steep increase in the number and distribution of asset exposure in the present century. The local-scale example demonstrates the potential sensitivity of erosion impacts to the distinctive coastal geomorphology of individual compartments. Our findings highlight that the benefits of applying a coastal sediment compartments framework increase with the coverage and detail of geomorphic data that is available to parameterise sediment-sharing systems and sediment budget principles. Such data is crucial to reducing uncertainty in forecasts by understanding the potential response of key sediment sources and sinks (e.g., the shoreface, estuaries) to sea-level rise in different settings.

Nested archetypes of vulnerability in African drylands: where lies potential for sustainable agricultural intensification?

Food production is key to achieving food security in the drylands of sub-Saharan Africa. Since agricultural productivity is limited, however, due to inherent agro-ecological constraints and land degradation, sustainable agricultural intensification has been widely discussed as an opportunity for improving food security and reducing vulnerability. Yet vulnerability determinants are distributed heterogeneously in the drylands of sub-Saharan Africa and sustainable intensification cannot be achieved everywhere in cost-effective and efficient ways. To better understand the heterogeneity of farming systems’ vulnerability in order to support decision making at regional scales, we present archetypes, i.e. socio-ecological patterns, of farming systems’ vulnerability in the drylands of sub-Saharan Africa and reveal their nestedness. We quantitatively indicated the most relevant farming systems’ properties at a sub-national resolution. These factors included water availability, agro-ecological potential, erosion sensitivity, population pressure, urbanisation, remoteness, governance, income and undernourishment. Cluster analysis revealed eight broad archetypes of vulnerability across all drylands of sub-Saharan Africa. The broad archetype representing better governance and highest remoteness in extremely dry and resource-constrained regions encompassed the largest area share (19%), mainly indicated in western Africa. Moreover, six nested archetypes were identified within those regions with better agropotential and prevalent agricultural livelihoods. Among these patterns, the nested archetype depicting regions with highest erosion sensitivity, severe undernourishment and lower agropotential represented the largest population (30%) and area (28%) share, mainly found in the Sahel region. The nested archetype indicating medium undernourishment, better governance and lowest erosion sensitivity showed particular potential for sustainable agricultural intensification, mainly in western and some parts of southeastern and eastern Africa. Insights into the nestedness of archetypes allowed a more differentiated discussion of vulnerability and sustainable intensification opportunities, enhancing the evaluation of key interlinkages between land management and food security. The archetypes may support the transfer of successful intensification strategies based on similarities among the drylands in sub-Saharan Africa.

Evaluating of the spatial heterogeneity of soil loss tolerance and its effects on erosion risk in the carbonate areas of southern China

Abstract. Soil loss tolerance (T value) is one of the criteria in determining the necessity of erosion control measures and ecological restoration strategy. However, the validity of this criterion in subtropical karst regions is strongly disputed. In this study, T value is calculated based on soil formation rate by using a digital distribution map of carbonate rock assemblage types. Results indicated a spatial heterogeneity and diversity in soil loss tolerance. Instead of only one criterion, a minimum of three criteria should be considered when investigating the carbonate areas of southern China because the one region, one T value concept may not be applicable to this region. T value is proportionate to the amount of argillaceous material, which determines the surface soil thickness of the formations in homogenous carbonate rock areas. Homogenous carbonate rock, carbonate rock intercalated with clastic rock areas and carbonate/clastic rock alternation areas have T values of 20, 50 and 100 t/(km2 a), and they are extremely, severely and moderately sensitive to soil erosion. Karst rocky desertification (KRD) is defined as extreme soil erosion and reflects the risks of erosion. Thus, the relationship between T value and erosion risk is determined using KRD as a parameter. The existence of KRD land is unrelated to the T value, although this parameter indicates erosion sensitivity. Erosion risk is strongly dependent on the relationship between real soil loss (RL) and T value rather than on either erosion intensity or the T value itself. If RL &gt; &gt; T, then the erosion risk is high despite of a low RL. Conversely, if T &gt; &gt; RL, then the soil is safe although RL is high. Overall, these findings may clarify the heterogeneity of T value and its effect on erosion risk in a karst environment.

基于生态重要性和敏感性的西南山地生态安全格局构建——以云南省大理白族自治州为例

PDF HTML阅读 XML下载 导出引用 引用提醒 基于生态重要性和敏感性的西南山地生态安全格局构建——以云南省大理白族自治州为例 DOI: 10.5846/stxb201610112046 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金面上项目（41271195） Building ecological security patterns in southwestern mountainous areas based on ecological importance and ecological sensitivity: A case study of Dali Bai Autonomous Prefecture, Yunnan Province Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:生态安全格局构建是快速城市扩张背景下缓解生态保护和土地开发矛盾、保证区域生态安全的有效途径。源地和阻力面是生态安全格局构建的重要基础，当前阻力面构建多关注生态要素而忽视与区域典型生态问题相对应的生态过程表征。以西南山地地区——云南省大理白族自治州为研究区，选取生物资源保护、水资源安全和营养物质保持等生态系统服务评估生态重要性从而识别源地，基于地质灾害、土壤侵蚀、石漠化等生态敏感性构建生态阻力面，并运用最小累积阻力模型识别组团廊道和景观廊道，从而构建山地生态安全格局。研究表明，大理州生态安全源地总面积14416.64 km2，占全州土地总面积的50.93%；关键生态廊道分为组团廊道和景观廊道两类，分别长404.7 km和208.4 km，以"一轴三带"形式呈树状辐射分布。生态安全格局中的生态源地和廊道应成为低丘缓坡土地资源开发中的禁止开发区。生态重要性源地识别和生态敏感性阻力面分析方法可为生态安全格局构建提供新思路，研究结果对于大理州山地城镇建设的用地选择和空间扩张提供定量指引。 Abstract:Ecological security in cities is attracting greater and greater attention owing to rapid urban expansion. Therefore, building ecological security patterns based on city landscapes is extremely meaningful and necessary for reconciling conflict between ecosystem conservation and land resource exploitation. Ecological sources and ecological resistance surfaces are important to ecological security patterns. However, previous studies regarding ecological resistance surfaces have mainly concentrated on the representation of ecological elements rather than ecological processes. In the present study, Dali Bai Autonomous Prefecture in Yunnan Province was used as the case study area. Ecological source patches were identified via evaluation of ecosystem service importance applying three aspects, namely biological resource protection, water security, and nutrient preservation. Ecological resistance surfaces were also built according to ecological sensitivity analysis from three aspects, i.e., rock desertification, geological disaster, and soil erosion sensitivity. Key ecological corridors were determined via the Minimum Cumulative Resistance model. The results demonstrated that the area of ecological sources was approximately 14416.64 km2, with all of the ecological source areas accounting for 50.93% of the Dali Prefecture. The key ecological corridors were 613.1 km long, including 404.7 km of cluster corridors and 208.4 km of landscape corridors. These ecological corridors were distributed in a branch shape and radial pattern, which appeared as one axis and three belts. All ecological sources and corridors should be planned as exploitation-prohibited regions during development in this mountainous area. The analysis of ecological sources based on ecological service importance and ecological corridors based on ecological sensitivity provides a new method for the construction of regional ecological security patterns. The results can offer effective spatial layout guidance for low-slope hilly land development in mountainous areas. 参考文献 相似文献 引证文献

Regional modelling of rainfall erosivity: sensitivity of soil erosion to aerosol emissions

A rainfall erosivity scheme is implemented into the widely used regional atmosphere–land model, WRF. Rainfall erosivity is parametrized from hourly precipitation and surface runoff in a high resolution (4 km) convection‐permitting model. The scheme is used to examine the potential effects of changes in atmospheric aerosol concentrations on soil erosion in a case‐study of northern India and the surrounding countries for the 2010 monsoon season, using a model which isolates the indirect effect on cloud microphysics only. This study offers a preliminary investigation into this emerging topic, but longer simulations would be needed to establish a robust signal.Summer precipitation is reduced in most areas and the monsoon circulation weakens for increases in cloud condensation nuclei concentrations. This can be attributed to localised cloud microphysical changes in the northeast of India, which induce a dynamic response opposing the monsoon circulation. The two regions of greatest decrease in erosion with increasing aerosol are in the Western Ghats and the Ganges Delta, both significant cropland areas. However, the effect is not uniform, with isolated local increases in soil erosion. These results suggest that, while efforts to reduce anthropogenic aerosol emissions may improve water availability for crops through enhanced rainfall, these benefits are likely to be tempered by an increase in soil erosion, though robust local changes were difficult to predict.

Regional modeling of wind erosion in the North West and South West of Iran

About two-thirds of the Iran’s area is located in the arid and semiarid region. Lack of soil moisture and vegetation is poor in most areas can lead to soil erosion caused by wind. So that the annual suffered severe damage to large areas of rich soils. Modeling studies of wind erosion in Iran is very low and incomplete. Therefore, this study aimed to wind erosion modeling, taking into three factors: wind speed, vegetation and soil types have been done. Wind erosion sensitivity was modeled using the key factors of soil sensitivity, vegetation cover and wind erodibility as proxies. These factors were first estimated separately by factor sensitivity maps and later combined by fuzzy logic into a regional-scale wind erosion sensitivity map. Large areas were evaluated by using publicly available datasets of remotely sensed vegetation information, soil maps and meteorological data on wind speed. The resulting estimates were verified by field studies and examining the economic losses from wind erosion as compensated by the state insurance company. The spatial resolution of the resulting sensitivity map is suitable for regional applications, as identifying sensitive areas is the foundation for diverse land development control measures and implementing management activities.

Role of Sensitivity of Erosion the Geological Formations at Erosion rate and Sediment Yield (Case Study: Sub-Basins of Doviraj River, Ilam Province)

Role of Sensitivity of Erosion the Geological Formations at Erosion rate and Sediment Yield (Case Study: Sub-Basins of Doviraj River, Ilam Province)

Solid Particle Erosion of HVOF Sprayed (35WC-Co/NiCrBSi Coating at Higher Temperature

High temperature erosion is generally encountered in boiler components in thermal power plants, especially in superheater, reheater, and economisers parts, where in fly ash particles attack the boiler components and cause high temperature erosion phenomena. It is known as fly ash erosion. The erosion behavior at elevated temperature is much different from that of room temperature erosion as there would be a higher erosion loss encountered at higher temperature due to higher plastic deformation as well as weak bonding between grains/particles. It is therefore imperative to study in depth the erosion wear assessment both at room temperature as well as at elevated temperature in the laboratory. This paper investigates thermal sprayed coatings produced by the high velocity oxygen fuel (HVOF) to improve the material performance under such conditions. 35 WC-NiCrBSi HVOF sprayed coatings were tested under high temperature (up to 700℃) erosion by means of an apparatus that simulated real conditions. The results showed that under these tests conditions the 35WC-NiCrBSi coating worn about 1.4 times less than bare SS-310 steel at room temperature and 300℃ Temperature, while at 700℃ C 35WC-NiCrBSi worns about 2 times higher than bare SS-310 steel at 90℃ impact angle. This shows 35WC-NiCrBSi erosion sensitivity at higher temperature.

Human Q fever incidence is associated to spatiotemporal environmental conditions

Airborne pathogenic transmission from sources to humans is characterised by atmospheric dispersion and influence of environmental conditions on deposition and reaerosolisation. We applied a One Health approach using human, veterinary and environmental data regarding the 2009 epidemic in The Netherlands, and investigated whether observed human Q fever incidence rates were correlated to environmental risk factors.We identified 158 putative sources (dairy goat and sheep farms) and included 2339 human cases. We performed a high-resolution (1×1km) zero-inflated regression analysis to predict incidence rates by Coxiella burnetii concentration (using an atmospheric dispersion model and meteorological data), and environmental factors – including vegetation density, soil moisture, soil erosion sensitivity, and land use data – at a yearly and monthly time-resolution.With respect to the annual data, airborne concentration was the most important predictor variable (positively correlated to incidence rate), followed by vegetation density (negatively). The other variables were also important, but to a less extent. High erosion sensitive soils and the land-use fractions “city” and “forest” were positively correlated. Soil moisture and land-use “open nature” were negatively associated. The geographical prediction map identified the largest Q fever outbreak areas. The hazard map identified highest hazards in a livestock dense area.We conclude that environmental conditions are correlated to human Q fever incidence rate. Similar research with data from other outbreaks would be needed to more firmly establish our findings. This could lead to better estimations of the public health risk of a C. burnetii outbreak, and to more detailed and accurate hazard maps that could be used for spatial planning of livestock operations.

Assessment of future scenarios for wind erosion sensitivity changes based on ALADIN and REMO regional climate model simulation data

AbstractThe changes in rate and pattern of wind erosion sensitivity due to climate change were investigated for 2021–2050 and 2071–2100 compared to the reference period (1961–1990) in Hungary. The sensitivities of the main influencing factors (soil texture, vegetation cover and climate factor) were evaluated by fuzzy method and a combined wind erosion sensitivity map was compiled. The climate factor, as the driving factor of the changes, was assessed based on observed data for the reference period, while REMO and ALADIN regional climate model simulation data for the future periods. The changes in wind erosion sensitivity were evaluated on potentially affected agricultural land use types, and hot spot areas were allocated. Based on the results, 5–6% of the total agricultural areas were high sensitive areas in the reference period. In the 21st century slight or moderate changes of wind erosion sensitivity can be expected, and mostly ‘pastures’, ‘complex cultivation patterns’, and ‘land principally occupied by agriculture with significant areas of natural vegetation’ are affected. The applied combination of multi-indicator approach and fuzzy analysis provides novelty in the field of land sensitivity assessment. The method is suitable for regional scale analysis of wind erosion sensitivity changes and supports regional planning by allocating priority areas where changes in agro-technics or land use have to be considered.