Soil erodibility for water and wind erosion and its relationship to vegetation and soil properties in China's drylands

Drylands with fragile socio-ecological systems are vulnerable to soil erosion. China's drylands face the dual threat of water (WAE) and wind erosion (WIE). To mitigate soil erosion in drylands, China has implemented numerous ecological restoration measures. However, whether vegetation and soil have different effects on soil erodibility for water erosion (soil erodibility, K) and wind erosion (soil erodible fraction, EF) in drylands is unclear, hindering decision makers to develop suitable ecological restoration strategies. Here, we conducted a large-scale belt transect survey to explore the spatial variation of K and EF in China's drylands, and examined the linear and nolinear effects of aridity (aridity index), vegetation (fractional vegetation cover and below-ground biomass), and soil properties (bulk density, total nitrogen, and total phosphorus) on K and EF. The results showed in China's drylands that the K ranges from 0.02 to 0.07, with high values recorded in the northern Loess Plateau and the eastern Inner Mongolia Plateau. The EF ranges from 0.26 to 0.98, and shows longitudinal zonation with higher values in the east and lower values in the west. Aridity has a negative linear effect on K and an inverse U-shaped nonlinear effect on EF. Aridity can affect K and EF by suppressing vegetation growth and disrupting soil properties. However, K and EF had different responses to some vegetation and soil variables. K and EF had opposite relationships with soil bulk density, and EF was significantly affected by fractional vegetation cover, while K was not. Overall, the effects of aridity and soil properties on soil erodibility were more pronounced than those from vegetation, whose effect on soil erodibility was limited. This study provides relevant information to support reducing soil water and wind erosion by highlighting the hotspot areas of soil erodibility, relevant for implementing vegetation restoration and soil conservation measures in drylands.

Response of soil erodibility of permanent gully heads to revegetation along a vegetation zone gradient in the loess-table and gully region of the Chinese Loess Plateau

Revegetation has been proven to significantly affect soil erodibility of gully heads, and climate conditions are expected to affect soil erodibility by determining the vegetation characteristic. However, there are crucial scientific/knowledge gaps regarding the change in the response of soil erodibility of gully heads to revegetation along a vegetation zone gradient. Therefore, we selected the gully heads with different restoration years along a vegetation zone gradient encompassing the steppe zone (SZ), forest-steppe zone (FSZ), and forest zone (FZ) on the Chinese Loess Plateau to clarify the variation in soil erodibility of gully head and its response to soil and vegetation properties from SZ to FZ. Furtherly, we systematically and comprehensively reveal driving factors of changes in soil erodibility in three vegetation zones. Results showed that: (1) Vegetation and soil properties were affected positively by revegetation and differed significantly in three vegetation zones. (2) Soil erodibility of gully heads in SZ was significantly higher than in FSZ and FZ, by 3.3 % and 6.7 % on average, respectively, and it showed a significantly different decrease with restoration years in three vegetation zones. (3) Standardized major axis analysis proved that the sensitivity of response soil erodibility to vegetation characteristics and soil characteristics presented a significant difference as the revegetation proceeded. Vegetation roots were the primary driver in SZ, but soil organic matter content dominated the change in soil erodibility in FSZ and FZ. (4) Structural equation modeling indicated that climate conditions played an indirect role in regulating soil erodibility of gully heads by mediating vegetation characteristics. This study offers essential insights for assessing the ecological functions of revegetation in the gully heads of the Chinese Loess Plateau under different climatic scenarios.

Impacts of soil conservation techniques on soil erodibility on an Alfisol

Soil erosion is a serious challenge for sustainable crop production. Alfisols in Nigeria are easily prone to soil degradations which have significantly reduced soil productivity, crop yield and increased cost of production. The use of soil conservation measures are vital interventions for sustainable crop production against the effects of erosion. The impacts of soil conservation on erodibility of an Alfisol was investigated in a tropical alfisol in Southwestern Nigeria. The study utilized four-soil conservation measures - Irvingia wombulu, Irvingia garbonensis, paddock and Cynodon plectostachyus was established on 20.4 ha land for 25 years, and replicated thrice based on land area. Empirical soil erodibility factor using Universal Soil Loss Equation (USLE) and Water Erosion Prediction Project (WEPP) erodibility factor models was determined. Analysis of variance analysis was done using R statistics to ascertain response patterns of the soil conservation measures to erodibility. Correlation was conducted for the conformity and relationship between erodibility models and soil properties. I. garbonensis soil conservation measure gave the least erodibility factor (K = 0.07), among paddock (K = 0.09), I. wombulu (K = 0.11) and C. plectostachyus with the highest erodibility factor (K = 0.17), indicating that I. garbonensis has the highest potential for soil conservation. Soil conservation measures significantly (p ≤ 0.05) influenced soil properties. Wischmeier and Mannering's USLE erodibility and WEPP's rill and inter-rill erodibility were not significantly (p ≥ 0.05) different across the soil conservation measures. Elswaify and Dangler's USLE erodibility correlated best with Wischmeier and Mannering USLE erodibility (r = 1.00) and WEPP's rill (r = 0.8) and inter-rill (r = 0.8) erodibility. Sand, silt, organic carbon, available phosphorus and aggregate stability significantly (p ≤ 0.05) correlated with USLE erodibility factor. Elswaify and Dangler USLE erodibility gave higher precision in erodibility determination of the soils. I. garbonensis was more efficient in reducing soil erosion, indicating that it is the best soil conservation measure for sustainable agriculture in alfisols in the tropics.

Soil aggregate disintegration effects on soil erodibility in the water level fluctuation zone of the Three Gorges Reservoir, China

Spatial hydrological alterations can affect soil structural stability. Over time, forces induced by water weaken soil aggregates and this has a negative implication to soil health. The Three Gorges Reservoir (TGR) in particular, experienced a long-term hydrological condition and repetitive seasonal water level fluctuations that could affect soil health. The present study was conducted to investigate the effects of different water levels on soil aggregate disintegration rate over time and its relation to soil erosion susceptibility in water reservoirs. Samples from different elevations (155 m, 160 m, 163 m, 166 m, 172 m, and 180 m) in the water level fluctuation zone (WLFZ) were exposed to continuous wet-shaking for 3, 9, 27, 54, and 81 min resulted to different WLF intensity accordingly. The results showed a comparative difference between aggregates size before and after the experiment where micro-aggregates (<0.25 mm) increased with respect to elevations increase. The exponential prediction proved that aggregate stability decreased with the increase of WLF intensity, insisting the effects of continuous hydrological stress to aggregate break-down. A couple of factors definitely confirmed that soil erodibility (k) is primarily determined by disintegration of soil aggregates for the surface soil of the TGR. Despite the fact that Disintegration rate (Dr) and k showed a positive relationship, R² = 0.73 (p < 0.05), the results showed that the soil properties decreasing Dr also decreases soil erodibility in the study area. Non-effective role of soil organic matter (SOM) for stabilizing soil aggregates was primarily related to water level fluctuations inhibiting decomposition. Relying on the present findings, environmental problems mostly soil erosion in the TGR could be therefore linked to excessive destabilization of soil aggregates. Therefore, the results of this study should play a major role in determining the factors primarily inducing soil erosion in river reservoirs.

Effects of land use types on soil erodibility in a small karst watershed in western Hubei

Background

Soil erosion is a severe problem in the karst watershed, and analysis of soil erosion at the watershed scale is urgently needed.

Methods

This study tried to estimate the soil erodibility factor (K-factor) using the Erosion Productivity Impact Calculator (EPIC) nomograph and evaluate the spatial distribution of the predicted K-factor in a karst watershed. Soil properties and K-factors of five land use types (NF: natural mixed forest, CF: cypress forest, EF: economic forest, ST: stone dike terrace, VF: vegetable land) in the Xialaoxi small watershed were compared and key factors affecting erodibility were analyzed.

Results

Results showed that (1) The erodibility K-factor was unevenly distributed within different site types and strongly influenced by anthropogenic activities. The soil K-factors of sample sites subjected to frequent human disturbance (ST, VF) were high, ranging from 0.0480-0.0520 t hm² h/(MJ mm hm²), while the soil K-factors of natural site types (NF, CF, and EF) were low, ranging from 0.0436-0.0448 t hm² h/(MJ mm hm²). (2) The soil texture in the Xialaoxi watershed was mostly loamy, and that of the agricultural areas frequently disturbed by agricultural practices (ST, VF) was silty loam. (3) Soil carbon fractions were affected by land use types. Soil organic carbon storage of NF and CF had strong spatial heterogeneity. The soil organic carbon (SOC) and labile organic carbon (LOC) of the two were significantly higher than those of the disturbed EF and cultivated land soil. (4) There was a synergistic effect between the soil properties and the K-factor. K was significantly negatively related to sand fractions (2-0.05 mm) and non-capillary porosity, while positively related to silt content (0.05-0.002 mm). Overall, changes in bulk density (BD), total porosity (TP), non-capillary porosity (NCP), texture, and organic matter content caused by natural restoration or anthropogenic disturbance were the main reasons for soil erodibility. Natural care (sealing) and construction of stone dike planting practices were effective ways to reduce soil erosion in small karst watershed areas of western Hubei.

Multifractal dimensions of soil particle size distribution reveal the erodibility and fertility of alpine grassland soils in the Northern Tibet Plateau

Climate change and human activities have seriously degraded alpine grassland, potentially affecting soil particle size distribution (PSD) and further influencing the nutrient levels and erodibility of soil. Predicting the fertility and erodibility of alpine soil using multifractal dimensions of soil PSD could be used to enhance the management and restoration of degraded alpine grasslands. In the present study, we evaluated three types of alpine grasslands: alpine meadow (AM), alpine steppe (AS), and alpine desert steppe (ADS). Fencing and grazing management measures were conducted at sites containing each grassland type. Then, we analyzed the PSDs, erodibility, and other properties of soil in the 0-20 cm soil layer. Multifractal characterization of soil PSD was calculated using the fractal scale theory. The findings showed that grassland type significantly impacted soil nutrients and the multifractal dimensions of soil PSDs, whereas management measures affected soil erodibility significantly. The proportion of finer particles decreased as follows: AM > AS > ADS. Compared to grazing, fencing enhanced clay content and reduced the proportion of coarser particles under all three grassland types. AM had higher organic carbon and nitrogen levels than AS and ADS. Multifractal dimensions were highest for AM, with ADS having higher erodibility than AM and AS. Multifractal dimensions (except for correlation dimension) also had significantly positive relationships with soil organic carbon and available nutrient content and soil erodibility, but had significantly negative correlations with soil pH, bulk density, and electrical conductivity. Thus, the multifractal dimensions of soil PSDs could be used to characterize the erodibility and fertility characteristics of soil in alpine regions, providing a reference for assessing vegetation restoration measures in the Northern Tibet Plateau.

Effects of vegetation restoration types on soil nutrients and soil erodibility regulated by slope positions on the Loess Plateau

Soil degradation is significantly increased driven by soil nutrient loss and soil erodibility, thus, hampering the sustainable development of the ecological environment and agricultural production. Vegetation restoration has been widely adopted to prevent soil degradation given its role in improving soil nutrients and soil erodibility. However, it is unclear which vegetation type has the best improving capacity from soil nutrient and soil erodibility perspectives. This study selected three vegetation restoration types of grasslands (GL), shrublands (SL), and forestlands (FL) along the five slope positions (i.e., top, upper, middle, lower, and foot slope), to investigate the effects of vegetation restoration types on soil nutrients and soil erodibility. All vegetation restoration types were restored for 20 years from croplands (CL). We used comprehensive soil nutrient index (CSNI) and comprehensive soil erodibility index (CSEI) formed by a weighted summation method to reflect the effect of vegetation restoration on the improving capacity of soil nutrient and erodibility. The results showed the vegetation types with the highest comprehensive soil quality index (CSQI) at the top, upper, middle, lower and foot slope were FL (1.92), FL (1.98), SL (2.15), FL (2.37) and GL (3.93), respectively. When only one vegetation type was considered on the entire slope, SL (0.59) and FL (0.59) had the highest CSNI, the SL had the lowest CSEI (0.34) and the highest CSQI (1.89). The CSNI was mainly influenced by soil structure stability index (SSSI), sand content, silt + clay particles, and CSEI was controlled by soil organic matter (SOM), macroaggregates and microaggregates. Moreover, the CSQI was influenced by pH, silt and clay content, and biome coverage (BC). The study suggested the SL were advised as the best vegetation restoration type on the whole slope from improving soil nutrients and soil erodibility.

Distribution of soil nutrients and erodibility factor under different soil types in an erosion region of Southeast China

Background

Soil erosion can affect the distribution of soil nutrients, which restricts soil productivity. However, it is still a challenge to understand the response of soil nutrients to erosion under different soil types.

Methods

The distribution of soil nutrients, including soil organic carbon (SOC), soil organic nitrogen (SON), and soil major elements (expressed as Al₂O₃, CaO, Fe₂O₃, K₂O, Na₂O, MgO, TiO₂, and SiO₂), were analyzed in the profiles from yellow soils, red soils, and lateritic red soils in an erosion region of Southeast China. Soil erodibility K factor calculated on the Erosion Productivity Impact Calculator (EPIC) model was used to indicate erosion risk of surface soils (0∼30 cm depth). The relationships between these soil properties were explored by Spearman’s rank correlation analysis, further to determine the factors that affected the distribution of SOC, SON, and soil major elements under different soil types.

Results

The K factors in the red soils were significantly lower than those in the yellow soils and significantly higher than those in the lateritic red soils. The SON concentrations in the deep layer of the yellow soils were twice larger than those in the red soils and lateritic red soils, while the SOC concentrations between them were not significantly different. The concentrations of most major elements, except Al₂O₃ and SiO₂, in the yellow soils, were significantly larger than those in the red soils and lateritic red soils. Moreover, the concentrations of major metal elements positively correlated with silt proportions and SiO₂ concentrations positively correlated with sand proportions at the 0∼80 cm depth in the yellow soils. Soil major elements depended on both soil evolution and soil erosion in the surface layer of yellow soils. In the yellow soils below the 80 cm depth, soil pH positively correlated with K₂O, Na₂O, and CaO concentrations, while negatively correlated with Fe₂O₃ concentrations, which was controlled by the processes of soil evolution. The concentrations of soil major elements did not significantly correlate with soil pH or particle distribution in the red soils and lateritic red soils, likely associated with intricate factors.

Conclusions

These results suggest that soil nutrients and soil erodibility K factor in the yellow soils were higher than those in the lateritic red soils and red soils. The distribution of soil nutrients is controlled by soil erosion and soil evolution in the erosion region of Southeast China.

Revegetation induced change in soil erodibility as influenced by slope situation on the Loess Plateau

Soil erodibility is an indispensable parameter for predicting soil erosion and evaluating the benefits of soil and water conservation. Slope situation can alter revegetation and its effects on soil properties and root traits, and thus may affect soil erodibility. However, whether slope situation will change the effect of revegetation on soil erodibility through improving soil properties and root traits has rarely been evaluated. Therefore, this study was conducted to detect the response of soil erodibility to slope situations (loess-tableland, hill-slope and gully-slope) in a typical watershed of the Loess Plateau. Five soil erodibility parameters (saturated soil hydraulic conductivity, SHC; mean weight diameter of aggregates, MWD; clay ratio, CR; soil disintegration rate, SDR; soil erodibility factor, K) and a comprehensive soil erodibility index (CSEI) are selected to clarify the study targets. The results revealed that soil properties, root traits, soil erodibility parameters and CSEI were affected by slope situation significantly. Soil and root can explain 79.7%, 79.1% and 69.8% of total variance in soil erodibility of loess-tableland, hill-slope and gully-slope, respectively. Slope situation influenced soil erodibility by changing the effects of revegetation on soil properties and root traits. Evidently, the slope situation greatly changed the relations between CSEI and soil and root parameters, whereafter a model considering slope situation (slope steepness), sand, organic matter content and root surface area density was reliable to estimate soil erodibility (CSEI). Our study suggested that the Armeniaca sibirica, the combination of Bothriochloa ischcemum and Robinia pseudoacacia and the combination of Armeniaca sibirica and Lespedeza bicolor can be used as the optimal selection for mitigating soil erodibility of loess-tableland, hill-slope and gully-slope, respectively. This study is of great significance in optimizing the spatial layout of soil and water conservation measures for different slope situations of the Loess Plateau.

Improved evaluation method of the soil wind erosion intensity based on the cloud-AHP model under the stress of global climate change

Under the stress of global climate change, soil wind erosion has become a major environmental issue in the Three-River Source Region (TRSR) of China. However, few large-scale studies have been conducted on soil wind erosion owing to the lack of investigational data or complex parameters. Moreover, the uncertainty and randomness in the weight determination process cannot be avoided using the traditional method. Thus, a cloud-analytic hierarchy process (cloud-AHP) model was proposed to construct a wind erosion intensity index model for the TRSR based on seven typical land surface parameters. The following results were obtained. (1) The cloud-AHP model can better eliminate the randomness and uncertainty in the weight determination process. (2) The proposed evaluation method of wind erosion intensity has better applicability in the TRSR with overall accuracy of 93%. (3) The overall wind erosion intensity in this region is moderate. The wind erosion intensity was the largest in the Yangtze River (0.55, moderate erosion) and smallest in the source region of the Lancang River (0.50, mild erosion). (4) Significant differences are observed in the influences of various vegetation types on wind erosion intensity. Bare land exhibits the highest wind erosion intensity, whereas a coniferous forest exhibits the smallest. Moreover, grassland is a key control zone of soil and water conservation because it has the largest spatial heterogeneity of internal erosion intensity. These results can provide data and technical support for preventing and controlling soil erosion and protecting the environment in the region.

Assessing soil degradation under land-use change: insight from soil erosion and soil aggregate stability in a small karst catchment in southwest China

Background

Soil erodibility (K factor) and soil aggregate stability are often used to assess soil degradation in an erodible environment. However, their applicability under land-use change is uncertain, especially agricultural abandonment.

Methods

Different land-use types, including cropland, abandoned cropland, and native vegetation land, were converted into the successive stages following agricultural abandonment by space-for-time substitution approach in a small karst catchment, Southwest China. The indexes of soil aggregate stability and K factor of the Erosion Productivity Impact Calculator (EPIC) model in soil profiles were calculated to identify which method is suitable to indicate soil degradation under land-use change.

Results

The indexes of soil aggregate stability in the soils at 0∼30 cm depth under native vegetation land were significantly larger than those under cropland and slightly larger than those under abandoned cropland. The K factor was not significantly different among the three land use examples because the EPIC model does not consider soil permeability. In the soil organic carbon (SOC)-rich soils (>2%), the K factor was significantly correlated with silt and clay content ranging within a narrow scope of near 0.010 t hm² h/hm²/MJ/mm. While in the SOC-poor soils, the K factor was significantly increased with decreasing SOC content and was significantly correlated with soil aggregate stability.

Conclusions

Soil aggregate stability is more suitable to indicate soil degradation under land-use change. Sufficient SOC in erodible soils would restrain soil degradation, while SOC loss can significantly increase soil erosion risk.

Validation of RUSLE K factor using aggregate stability in contrasted mediterranean eco-geomorphological landscapes (southern Spain)

Mediterranean mountains are facing great environmental and socioeconomic challenges in the current framework of Global Change. One of these is soil degradation, which is one of the major threats in those territories. Soil degradation is more dramatic where eco-geomorphology and land uses with less vegetation cover promote soil erosion. Soil erosion is influenced by soil erodibility, which can be assessed by different methodologies, e.g. RUSLE K factor and aggregate stability of soils. This study deals with the validation of RUSLE K factor by means of soil aggregate stability analysed in two-contrasted watersheds from one Mediterranean mountainous region in South of Spain, under sub-humid and semiarid climatic conditions. In both of them, landscape dynamic from 1956 to 2016 was analysed in order to characterize the modifications in land uses. A total of 361-soil samples was also taken covering all land uses for analysing aggregate stability of soils as well as those soil properties needed to calculate the RUSLE K factor. The results indicated that: i) landscape dynamic was influenced by changes in land uses contributing mainly to an increment in vegetation cover in the rainiest watershed; ii) the analysed soil properties showed very few significant differences between watersheds and between land uses, especially regarding organic matter content; and iii) the validation of K Factor using aggregate stability was better in the rainiest watershed and, within this one, in the natural land uses and irrigated cultivations, meaning where the biotic factors were more influential. These results implicated more researches are necessary, principally, focussed on the validation of the RUSLE K parameter using different fractions of aggregates as well as considering other eco-geomorphological parameters.

Impact of land cover types on soil aggregate stability and erodibility

Gökçeada is the biggest island, and it is also known as the organic island of Turkey. Approximately 65% of the Gökçeada lands have slope > 12%. Climate, topography, land cover, and soil characteristics are considered to be the main natural factors affecting soil erosion severity in the Gökçeada. Prevention of soil degradation, hence the preservation or improvement of the overall quality of the soil, is directly related to the presence of stable soil aggregates. In addition, the resistance to weathering and replacement of soil particles are also relevant aspects in terms of sustainability. Aggregate stability (AS) and erodibility of land (Kfac) are related to soil properties. However, this relationship can vary under different circumstances. In this study, 248 surface soil samples have been taken from forest and semi-natural areas (FSNA) and agricultural areas (AGRA) according to CORINE 2006. Eleven selected soil properties were measured, and their impacts on AS and Kfac (RUSLE-K) were determined by using the CRT (classification and regression tree) in Gökçeada. Results showed that the relations among soil characteristics changed according to the land cover classes. Total organic carbon is much more associated with AS in AGRA, while total carbon is associated with AS in FSNA. The effect of calcium carbonate on Kfac was higher than other soil properties when the land cover type was ignored. On the other hand, in AGRA, the effect of between clay content on Kfac was greater than those of FSNA.

Evaluation of the rusle and disturbed wepp erosion models for predicting soil loss in the first year after wildfire in NW Spain

Severe fire greatly increases soil erosion rates and overland-flow in forest land. Soil erosion prediction models are essential for estimating fire impacts and planning post-fire emergency responses. We evaluated the performance of a) the Revised Universal Soil Loss Equation (RUSLE), modified by inclusion of an alternative equation for the soil erodibility factor, and b) the Disturbed WEPP model, by comparing the soil loss predicted by the models and the soil loss measured in the first year after wildfire in 44 experimental field plots in NW Spain. The Disturbed WEPP has not previously been validated with field data for use in NW Spain; validation studies are also very scarce in other areas. We found that both models underestimated the erosion rates. The accuracy of the RUSLE model was low, even after inclusion of a modified soil erodibility factor accounting for high contents of soil organic matter. We conclude that neither model is suitable for predicting soil erosion in the first year after fire in NW Spain and suggest that soil burn severity should be given greater weighting in post-fire soil erosion modelling.

Interaction between ash and soil microaggregates reduces runoff and soil loss

Areas subjected to fire have a two-layer system (i.e., ash and soil), which brings enormous complexities to hydrogeomorphic processes. In addition, the combinations of variables from the ash and the soil characteristics result in several possible two-layer system contexts. Here, the interactions among ash and microaggregates (i.e., ash placed over fine soil microaggregates) and their effects on hydro-erosional processes are explored. The ash was produced by an experimental fire and collected from a field managed by a slash-and-burn agricultural system. The design of the experiment included a strategy for considering combinations in which each of the various factors of interest, i.e., ash and microaggregates, was present or absent. In addition, the study searched for interactions between the two factors when both were present. In total, 600 g m² of fine ash mixture (<0.250 mm), obtained from fire at different temperatures, and 90 g m² of microaggregates was placed over a small splash pan (0.135 m²). Next, a rainfall of 56 mm h^-1 lasting for 30 min was applied in four replicates for each treatment: 1) bare soil, 2) bare soil + microaggregates, 3) ash, and 4) ash + microaggregates. The interaction between the ash and soil microaggregates changed the soil hydrology dynamics, reducing soil moisture by 28% and surface runoff by 78%. The ash-microaggregates combination reduced soil loss by sheetwash by 20% and by rainsplash by 25%. Overall, the ash treatment increased soil loss by 47% compared to the case of bare soil. On the contrary, the ash-microaggregates interaction decreased soil loss by 26% compared to the ash treatment.

Effects of land conversion from native shrub to pistachio orchard on soil erodibility in an arid region

Land-use change through degrading natural vegetation for agricultural production adversely affects many of soil properties particularly organic carbon content of soils. The native shrub land and grassland of Gaziantep-Adiyaman plateau that is an important pistachio growing eco-region have been cleared to convert into pistachio orchard for the last 50 to 60 years. In this study, the effects of conversion of natural vegetation into agricultural uses on soil erodibility have been investigated. Soil samples were collected from surface of agricultural fields and adjacent natural vegetation areas, and samples were analyzed for some soil erodibility indices such as dispersion ratio (DR), erosion ratio (ER), structural stability index (SSI), Henin's instability index (I _s ), and aggregate size distribution after wet sieving (AggSD). According to the statistical evaluation, these two areas were found as different from each other in terms of erosion indices except for I _s index (P < 0.001 for DR and ER or P < 0.01 for SSI). In addition, native shrub land and converted land to agriculture were found different in terms of AggSD in all aggregate size groups. As a contrary to expectations, correlation tests showed that there were no any interaction between soil organic carbon and measured erodibility indices in two areas. In addition, significant relationships were determined between measured variables and soil textural fractions as statistical. These obtaining findings were attributed to changing of textural component distribution and initial aggregate size distribution results from land-use change in the study area. Study results were explained about hierarchical aggregate formation mechanism.