Soil Erosion Risk Research Articles

Spatiotemporal variability of rainfall erosivity and its teleconnection with atmospheric circulation in monsoon-driven climate region

Understanding the spatiotemporal variability of annual, monthly, and seasonal rainfall erosivity (RE) is crucial for determining the risk of soil erosion and developing soil conservation plans. However, little knowledge is available on RE at the monthly, seasonal, and annual scales in monsoon-driven climate regions like Bangladesh. Therefore, we aimed to assess the spatiotemporal variability of RE in Bangladesh from 1980 to 2017 and analyze teleconnection of RE with large-scale atmospheric circulation indices. The detrended fluctuation analysis (DFA) and cross wavelet analysis were employed to evaluate the potential future trends and interpret the periodic cycles in the RE, respectively. The results demonstrate that mean annual RE values fluctuated from 12574.16 MJ.mm.ha-1.h-1 to 123914.76 MJ.mm.ha-1.h-1, while RE has been lower in recent decades than in the earlier decades. The mean annual RE is decreasing all over the country, and significant abrupt change points occurred in the early 2000 s. The highest mean annual RE was observed in the southernmost part of Bangladesh and the lowest in the western part of the country. The results of DFA indicated that the RE trend would sustain its present trend in the upcoming period, except for May and July. The effects of Niño3.4 SST and IOD, SASMI, and EASMI have almost no to minimal influence on the RE trend in Bangladesh. However, a noticeable impact was found on the monthly scale, which could be why the observed intra-annual variability of RE was observed. We found that the average RE has reduced significantly with increasing distance from the sea, latitude, and elevation in Bangladesh. The study found that increasing geopotential height in the summer and decreasing geopotential height in the winter with enough moisture divergence, decreasing convective precipitation, decreasing large-scale rain rate, decreasing specific cloud liquid water content, and decreasing explicit rainwater content all contributed to RE variability and change in the country.

Decade-long unsustainable vegetation management practices increase macronutrient losses from the plant-soil system in the Taklamakan Desert

Arid ecosystems are characterized by low availability and mobility of soil nutrients and slow geochemical cycles. Management of native vegetation in such ecosystems for fuel, livestock grazing, and other agricultural activities (burning and cutting) may threaten semi-natural communities due to the changes in nutrient cycles and soil fertility. Alhagi sparsifolia is a dominant perennial legume in the Taklamakan Desert of northwestern China and has been used as fodder for livestock and plays a crucial ecological role in stabilizing dunes in the oasis-desert ecotone. We evaluated the effects of long-term (12 years) burning and cutting of plant biomass on the mineral nutrition of A. sparsifolia and associated soils at two depths (0–50 and 50–100 cm) in the field conditions following the block design experiment. We found that burning effects tended to be restricted to the topsoil (0–50 cm), and the concentration of many micro-and macronutrients was increased. Burning was associated with a decrease in plant nitrogen (N) and phosphorus (P) concentration, whereas concentrations of other micro-and macronutrients increased; overall, burning reduced foliar stocks of N, P, and potassium (K). Annual cutting elicited smaller increases in soil mineral (total sulfur, total P, calcium, magnesium, and available P and K) concentrations than burning, and soil enzymatic activities increased. There were contrasting response patterns of leaf N and P concentration and macro-and micronutrients between the two management approaches. Burning and cutting reduced leaf N and P concentrations, while changes in root and shoot N and P concentrations depended on treatments. Thus, burning and cutting of A. sparsifolia impact organ nutrient stoichiometry (increased losses of macronutrients from arid plant-soil ecosystems) and nutritional quality (for feeding livestock), particularly due to predicted rises in extreme climatic events under climate change that are expected to increase risks of soil erosion, however, impacts on native trophic webs remain unclear.

Soil erosion risk under climate change scenarios: A case study in rural area with varying land uses

Soil erosion is one of the major issues in the tropics. The erosion is highly affected by the changes in climate and land cover. Future changes in tropical climate, particularly precipitation are expected to influence the potential risks of soil erosion. In the face of rapid changes in rural land cover for agricultural purposes, the combined forcings of land cover and climate changes have been to be a major threat to the soil conservation due to soil erosion. In this study, climate change scenarios at the northern part of Borneo were developed based on the RCP 4.5 and RCP 8.5 climate scenarios using Weather Research Forecast Model (WRF). The future climate projection scenarios of the total precipitation were used to simulate the potential erosion risks in varying land covers in a rural area of Sabah, Malaysia. The RUSLE model was used for soil erosion modelling, which was integrated with IDRISI Selva that allow the analysis and assessment of erosion risk. The variability of future total precipitations in the area of varying land cover types have resulted in varying degree of potential soil erosion risk The average soil loss at the studied area has increased by 262 t/ha/yr with 35.94 % increment in annual precipitation under RCP 8.5 emission scenario. However, under RCP 4.5, 26.65 % decrement in precipitation has reduced the soil loss by 315.1 t/ha/yr. In this rural area, exceptionally high soil erosion was found at steep slopes and thin vegetation covers. Therefore, an appropriate land use planning, soil conservation practices, and strategic adaptation options plan should be created and developed to ensure the sustainability of the soil conservation and enhance rural agricultural productivity.

DETERMINATION OF THE IMPACT OF FOREST FIRES ON SOIL EROSION RISK BY USING THE ICONA MODEL: A CASE STUDY OF AYVALI DAM WATERSHED

Soil erosion in dam watersheds is a crucial phenomenon since dams have become a critical component of economic development for many countries. Therefore, the expected increase in both forest fires and heavy rains in the Mediterranean region poses a threat to the dam watersheds. The increase of these two phenomena will cause a serious increase in soil erosion after forest fires in dam watersheds. Therefore, revealing the possible effects of forest fires on soil erosion risk will be extremely beneficial for taking proactive measures in the management of dam watersheds. So, the goal of this study is to reveal the soil erosion risk and to determine the effect of possible forest fires on the soil erosion risk in the Ayvalı dam watershed. The ICONA model was used to reveal the soil erosion risk in the study area. The effect of forest fires was determined by scenario analysis. In the forest fire scenario, it is assumed that all forests in the study area are burned. Considering this scenario, a new soil erosion risk map was produced with the model. Then these two maps were compared. The results showed that 70.33% of the study area faced very high erosion risk, while 21.65%, 7.19%, 0.77%, and 0.05% of it had high, medium, low, and very low erosion risk, respectively. This potentially very high risk results from the steep slopes, high soil erodibility, and sparse vegetation density in the study area. As a result of the fire scenario, it was determined that while the areas with the very high risk increased by 18.11%, areas with high, medium, low, and very low risk decreased by 48.55%, 26.36%, 35.43%, and 100%, respectively. The findings can be a guide for decision-makers to prioritize necessary precautions depending on the soil erosion potential before and after forest fires.

Spatiotemporal patterns and drivers of soil erosion in Yunnan, Southwest China: RULSE assessments for recent 30 years and future predictions based on CMIP6

Soil erosion is a critical driving force of regional-scale ecosystem dynamics. Quantifying soil erosion and its responses to climate and land cover changes comprise an important part of regional ecological security assessment. Taking account of rainfall and vegetation cover changes in Yunnan Province, Southwest China, from 1986 to 2015, this study explored the spatiotemporal patterns of soil erosion intensity in Yunnan over this 30-year period, using the Revised Universal Soil Loss Equation. Sensitivity analyses were performed to evaluate the roles of rainfall (R) and vegetation cover (C) changes in soil erosion. Based on the climate model CMIP6, the carbon emission socio-economic sharing scenarios SSP126 and SSP585 were compared, using a random forest model, to predict soil erosion risk in Yunnan in different future periods. The results indicated the following: (1) During 1986–2015, soil erosion was detected in 33.55% of the land area of Yunnan, among which the areas of slight, moderate, severe, very severe, and extremely severe erosion accounted for 19.55%, 7.64%, 3.23%, 2.08%, and 1.04%, respectively; the 30-year mean annual soil erosion modulus over Yunnan was 1289.72 t km−2 a−1. (2) The area percentage change of five soil erosion intensity levels consistently showed a generally declining trend of soil erosion during the 30-year period. Comparing 1995–2006 vs. 1986–1995 and 2006–2015 vs. 1996–2005, area percentages were 1.56% and 2.4% for intensively reduced, respectively, and correspondingly 16.65% and 22.12% for reduced, 68.11% and 71.15% for no significant change, 12.79% and 4.02% for enhanced, and 0.08% and 0.03% for intensively enhanced. (3) Factor C was a more sensitive driver than R for soil erosion in this period. (4) Under the SSP126 and SSP585 scenarios, soil erosion risk was predicted to rise in the 21st century; and the provincial average soil erosion risk was larger for the SSP585 than the SSP126 scenario. Compared with the average of the 30-year period, predicted soil erosion in the SSP585 and SSP126 scenarios in 2100 would increase in western and southern Yunnan, while the SSP585 scenario predicted more severe soil erosion in southern and southwestern regions than SSP126. Our historical assessments and future forecasts suggest vegetation protection in karst areas and restoration in southern Yunnan will be critical for future soil erosion control and regional ecological security in Yunnan.

Remote sensing technique and ICONA based-GIS mapping for assessing the risk of soil erosion: A case of the Rudbar Basin, Iran

Remote sensing technique and ICONA based-GIS mapping for assessing the risk of soil erosion: A case of the Rudbar Basin, Iran

Quantitative soil erosion risk assessment due to rapid urbanization in the Cox’s Bazar district and Rohingya refugee camps in Bangladesh

Soil erosion due to anthropogenic interventions is an emerging threat to the south-eastern coastal districts of Bangladesh. In the recent decade, land degradation intensified this process in this region due to the settlement of the Forcibly Displaced Myanmar Nationals popularly known as ‘Rohingya’, who fled from Myanmar in 2017. To control soil erosion, it is necessary to identify the soil erosion locations and their intensity. The present study has attempted to quantify the regional soil loss (from 2015 to 2020) using the Revised Universal Soil Loss Equation model. In this method, soil erosion risk assessments are carried out by integration of different physiographic parameters in the spatial dimension. Results showed that the year 2015 and 2020 witnessed mean soil erosion at a rate of around 58.2 and 59 t ha− 1 yr− 1, respectively in the Cox’s Bazar district in which 20–21% of the study area was highly subjected to soil erosion. But in the Rohingya camps mean soil erosion for these periods is 59 and 78 t ha− 1 yr− 1, respectively with a cumulative increase of 32%. The sub-districts adjacent to the Rohingya refugee camps (Ramu, Ukhia, and Teknaf) have experienced intense erosion compared to the others. From 2015 to 2020, a large increase of about 4.54 (6%) t ha− 1 yr− 1 is observed in the Palongkhali union whereas a maximum decrease of about − 8.08 (23%) t ha− 1 yr− 1 is observed in the Pokkhali union. In Rohingya camps, the worst soil erosion-affected areas are the camps 8E, 10, 14, 15, 16, and 17 having more than 100 t ha− 1 yr− 1 mean soil loss. The geographic detector method is used to identify the influence of different factors on soil erosion. Land use change is found to be the major contributing factor to soil erosion increase from 2015 to 2020. The spatial variations are significantly controlled by slope and elevation factors. This work can help to understand the dynamics of soil erosion and the knowledge can be used for conservation planning in the Cox’s Bazar and Rohingya camp areas.

Assessing soil erosion risk in a peri-urban catchment of the Lake Victoria basin.

Soil erosion and sedimentation contribute to deteriorating water quality, adverse alterations in basin hydrology and overall ecosystem biogeochemistry. Thus, understanding soil erosion patterns in catchments is critical for conservation planning. This study was conducted in a peri-urban Inner Murchison Bay (IMB) catchment on the northern shores of Lake Victoria since most soil erosion studies in Sub-Saharan Africa have been focused on rural landscapes. The study sought to identify sediment sources by mapping erosion hotspots using the revised universal soil loss equation (RUSLE) model in appendage with field walks. RUSLE model was built in ArcGIS 10.5 software with factors including: rainfall erosivity, soil erodibility, slope length and steepness, land cover and support practices. The model was run, producing an erosion risk map and field assessments conducted to ground-truth findings and identify other hotspots. The percentage areas for RUSLE modelled erosion rates were: 66.8% for 0-2 tha-1year-1; 10.8% for 2-5 tha-1year-1; 10.1% for 5-10 tha-1year-1; 9% for 10-50 tha-1year-1 and 3.3% for 50-100 tha-1year-1. Average erosion risk was 7 tha-1year-1 and the total watershed erosion risk was 197,400 tyear-1, with croplands and steep areas (slope factor > 20) as the major hotspots (> 5 tha-1year-1). Field walks revealed exposed soils, marrum (gravel) roads and unlined drainage channels as other sediment sources. This study provided the first assessment of erosion risk in this peri-urban catchment, to serve as a basis for identifying mitigation priorities. It is recommended that tailored soil and water conservation measures be integrated into physical planning, focusing on identified non-conventional hotspots to ameliorate sediment pollution in Lake Victoria.

Effects of Moss Overlay on Soil Patch Infiltration and Runoff in Karst Rocky Desertification Slope Land

The growth and overlay of a large number of bryophytes in the broken soil patches between the exposed bedrocks of karst have an essential influence on the infiltration and runoff process between the exposed bedrocks and even the whole rocky desertification area. The purpose of this study is to explore the effects of moss on the infiltration and runoff of soil patches between karst exposed bedrocks and the processes of rainfall, runoff and infiltration transformation on slopes through rainfall experiments. The results showed that the slopes between the karst outcrops are dominated by subsurface and underground pore runoff. More than 50% of precipitation is lost through underground pores, with surface runoff accounting for only 1–17% of the total. Bryophyte overlay significantly reduced the initial runoff from subsurface and underground pore runoff, and advanced the steady-state time of runoff from subsurface and underground pore runoff, suggesting that bryophyte coverage may reduce the risk of soil erosion caused by short-duration rainfall. Eurohypnum has a significant inhibitory effect on percolation between exposed bedrock and reduces rainfall leakage from subsurface and underground pores. Thuidium has a strong intercepting effect on rainfall, significantly reducing the formation of surface runoff and the risk of surface soil erosion. Moss overlay has an essential role in soil and water conservation between karst exposed bedrock, and Eurohypnum and Thuidium can be considered as pioneer mosses for ecological restoration in the process of rocky desertification control and ecological restoration, which can effectively solve the serious problem of soil and water loss in karst rocky desertification area and improve the benefit of soil and water conservation in karst area.

Quantify soil erosion and sediment export in response to land use/cover change in the Suha watershed, northwestern highlands of Ethiopia: implications for watershed management

Soil erosion accelerated by human activities is a critical challenge affecting soil health, agricultural productivity, food security and environmental sustainability in the highlands of Ethiopia. The aim of this study was to examine the dynamics of soil loss and sediment yield potential, and identify soil erosion hotspots using RUSLE with GIS in the Suha watershed, north western highlands of Ethiopia. Digital Elevation Model, LU/LC, rainfall, soil, and conservation practice were used as input data for RUSLE model. The estimated total annual soil loss for the entire watershed increased from 1.22 million tons in 1985 to 2.43 million tons in 2019, with average annual soil loss rates of 15.2 t ha−1 yr−1 and 31.4 t ha−1 yr−1 respectively. Total sediment yield also increased from 317.52 to 630.85 thousand tons over the past 35 years. In addition, the area of soil erosion hotspots changed from 15.2% (12,708 ha) to 32% (25,660 ha) during the same periods. Sub watershed 1, 2, 15, 17, 18, and 23 are severely degraded parts of the watershed. Expansion of agriculture and bare land as the expenses of other land use types over the past 35 years could be the major causes of extensive soil erosion risk in the watershed. Besides its temporal variability, soil loss and sediment export also showed variation between land use/cover classes. The estimated results of soil loss and sediment yield as well as soil erosion hotspots revealed that the soil erosion risk is progressively increasing during the study periods. Unless action is taken and the current condition is reversed, it will critically threat the livelihoods of the community in the watershed. Generally, the results underscore urgent demand for integrated and effective watershed management strategies.

Changes in the characteristics of flood discharge and sediment yield in a typical watershed in the Hengduan Mountain Region, Southwest China, under extreme precipitation events

Precipitation extremes can pose adverse impacts on local and downstream society, economy, and ecosystems. Accordingly, their characteristics have attracted widespread attention in many regions, such as the world famous Hengduan Mountain Region in Southwest China, where the overall characteristics in precipitation extremes have been widely reported yet. However, the spatial heterogeneity and internal variation of precipitation extremes caused by the complicated topography were rarely reported, moreover, few studies have evaluated the effect of dynamics in precipitation extremes and soil and water conservation measures on changes in flood discharge and sediment yield. In this study, a typical watershed in the Hengduan Mountain Region, the Longchuanjiang watershed, was selected to identify the dynamics in precipitation extremes from 1965 to 2018, and the contributions of soil and water conservation measures on the characteristics in flood discharge and sediment load. The results of this study are as follows. 1) Substantial decreasing trends occurred for both flood discharge and sediment yield from the early period (1965–2008) to the later period (2009–2018) in the Longchuanjiang watershed. 2) The increase in precipitation extremes in the dry-hot valley and decrease in the mountains revealed great internal variation of the characteristics in precipitation extremes in the Longchuanjiang watershed.3) Soil and water conservation measures that were implemented in recent decades, such as terraced farmland, forest and grass plantation, ecological restoration, and small reservoirs, resulted in the significant reduction of both flood discharge and sediment yield under similar extreme precipitation events. This study highlights the discrepancy of dynamics in precipitation extremes in the dry valleys with an entire watershed in the Hengduan Mountain Region, emphasizes the risks of soil erosion in the ecologically fragile dry valley, and assesses the contribution of soil and water conservation measures on changes in characteristics of flood discharge and sediment load in the selected watershed. The study results are of great importance not only for gaining a scientific understanding of changes in precipitation extremes, flood discharge, and sediment yield but also for the objective assessment of the ecological benefits of soil and water conservation projects and deployment of suitable measures in the future.

Quantifying the Effects of Root and Soil Properties on Soil Detachment Capacity in Agricultural Land Use of Southern China

Unsustainable agricultural land use will lead to an increased risk of soil erosion and soil degradation. However, few studies have investigated impacts of changes in root and soil properties on the soil detachment process. Therefore, we investigated the effects of agricultural land use on the relative contribution of root and soil properties to soil detachment capacity. Soil samples were collected from six different land use types and subjected to flow scouring under six shear stresses ranging from 4.98 to 16.37 Pa. Agricultural land use influenced root distribution and soil properties in the soil surface layer. Root length density, root surface area density, and root volume density in orchards with no cover, orchards with grass cover, and farmland were less than those of grassland samples. Different land use types affected soil detachment capacity. Bare land, farmland, and orchards with no cover were more vulnerable to erosion, while forest, orchard with grass cover, and grassland showed little soil detachment. Soil detachment capacity decreased exponentially with increasing soil bulk density, aggregate stability, organic matter, and root mass density. The root mass density and aggregate stability had the greatest contribution to the soil detachment capacity. Agricultural land use increases the risk of soil erosion; a groundcover management strategy, such as planting grass in orchard, could effectively increase the fine root distribution and aggregate stability to control soil erosion.

Spatiotemporal dynamics of soil loss and sediment export in Upper Bilate River Catchment (UBRC), Central Rift Valley of Ethiopia

Soil loss is one of the major challenges for agricultural production in the Ethiopian highlands. The rate and distribution of soil loss (SL) and sediment export (SE) are essential to map degradation “hotspot” areas for prioritizing soil and water conservation measures. The objective of this study was to estimate the dynamics of SL and SE in the Upper Bilate River Catchment of Central Ethiopia. The Sediment Delivery Ratio (SDR) module of the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model was used to estimate and map SL and SE. The primary input data were rainfall, soil data, land use, and other biophysical parameters of the study area. The model output confirmed that the average total soil loss of the catchment was 36.8 million ton/yr. It is modeled that soil loss doubles within 30 years. The average annual sediment export was about 3.62 ton/ha/yr. The mean annual soil loss of the study area was 23 ton/ha/yr, which exceeded the soil loss tolerance (SLT), estimated to range between (2–18 ton/ha/yr) in Ethiopia. Based on the soil erosion risk level, about 22% of the catchment area was classified as severely degraded, while 62 % was moderately degraded. Severe soil erosion prevails in the sub-watershed (SW)-5, SW-4, and SW-13. Therefore, these sub-watersheds need priority conservation action to restore the ecosystem processes of the study area.

Using Google Earth Engine and GIS for basin scale soil erosion risk assessment: A case study of Chambal river basin, central India

Using Google Earth Engine and GIS for basin scale soil erosion risk assessment: A case study of Chambal river basin, central India

Remote Sensing-Based Land Suitability Analysis for Forest Restoration in Madagascar

Tropical forest loss has been a prominent concern in Madagascar, portrayed by a highly fragmented landscape of forests surrounded by small-scale agricultural patches along the northwestern and eastern regions. This paper seeks to identify priority areas for forest landscape restoration at a landscape scale using a geospatial land suitability analysis approach. The study area is the watershed of Mahavavy, home to one of the most biodiverse ecosystems in the island but also an important agriculture region. The suitability analysis method comprises five major steps: (1) the identification of a set of restoration criteria, (2) the acquisition of available environmental datasets for each criterion, (3) generating suitability maps for each criterion, (4) the conception of a suitability analysis model, and (5) the design of potential sites for restoration. The specific suitability criteria combine both landscape composition and soil characteristics, including (i) distance from protected sites and forest patches, (ii) land cover classes, (iii) distance from settlements, (iv) distance from roads, (v) risk of soil erosion. We found 143,680 ha (27.9%) that were highly suitable areas for forest landscape restoration, 159127 (30.9%) moderately suitable and138031 ha (26.6%) not suitable areas. High potential suitable areas are observed in close proximity of forest patches and protected areas, and low restoration feasibility in all areas that are easily accessible and thus subjected to exploitation.

Using soil erosion as an indicator for integrated water resources management: a case study of Ruiru drinking water reservoir, Kenya

Functions and services provided by soils play an important role for numerous sustainable development goals involving mainly food supply and environmental health. In many regions of the Earth, water erosion is a major threat to soil functions and is mostly related to land-use change or poor agricultural management. Selecting proper soil management practices requires site-specific indicators such as water erosion, which follow a spatio-temporal variation. The aim of this study was to develop monthly soil erosion risk maps for the data-scarce catchment of Ruiru drinking water reservoir located in Kenya. Therefore, the Revised Universal Soil Loss Equation complemented with the cubist–kriging interpolation method was applied. The erodibility map created with digital soil mapping methods (R2 = 0.63) revealed that 46% of the soils in the catchment have medium to high erodibility. The monthly erosion rates showed two distinct potential peaks of soil loss over the course of the year, which are consistent with the bimodal rainy season experienced in central Kenya. A higher soil loss of 2.24 t/ha was estimated for long rains (March–May) as compared to 1.68 t/ha for short rains (October–December). Bare land and cropland are the major contributors to soil loss. Furthermore, spatial maps reveal that areas around the indigenous forest on the western and southern parts of the catchment have the highest erosion risk. These detected erosion risks give the potential to develop efficient and timely soil management strategies, thus allowing continued multi-functional use of land within the soil–food–water nexus.

A field parcel-oriented approach to evaluate the crop cover-management factor and time-distributed erosion risk in Europe

The crop cover-management (C-) factor in arable landscapes describes the soil erosion susceptibility associated with seasonally cultivated crops. Previous informatic and computational limitations have led many modelling studies to prescribe C-factor values and assume spatial and temporal stationarity. However, the multiple influencing factors ranging from parcel-scale crop cultivation and management to regional-scale rainfall regimes motivates new methods to capture this variation when identifying at-risk areas. Here, we define a multi-component method to derive the C-factor by associating time series of canopy and residue surface cover from Sentinel-2 and climate-specific rainfall erosivity with Integrated Administration and Control System (IACS) field parcel data from European Union member states. A scalable and standardised method is emphasised to increase the future interoperability and inter-comparability of soil erosion modelling studies deploying the C-factor. Additionally, field parcel simulation units with associated crop declarations provide a new reference scale to link predictions of soil erosion risk with specific management decisions and declarations by farmers. After implementing the method on a homogenised subsample of 8600 field parcels covering available IACS regions, several key findings are outlined: 1) time series information provides new opportunities to predict the time-criticality of erosion in specific crop cultivations, 2) the varying (a-)synchronicity between seasonal crop canopy cover and heavy rainstorms means that spatial variability is inherent within the C-factor across Europe, and 3) the addition of agricultural management practices (e.g. tillage practice descriptions) to open-access IACS repositories can facilitate more comprehensive evaluations of the C-factor and soil erosion risk.

Effect of different vegetation restoration on soil properties in the semi-arid Loess Plateau of China

Vegetation restoration on the Loess Plateau has decreased soil erosion. However, the comprehensive effects of different vegetation restoration types on soil properties are not clear. Evaluating the soil properties of the main economic and ecological tree species on the Loess Plateau can provide crucial guidance for regional ecological environment restoration. Therefore, we compared soil water content (SWC), soil particle composition, root distribution, soil organic carbon (SOC) content, soil bulk density (BD), total porosity (TP), saturated hydraulic conductivity (Ks), soil water retention curves (SWRCs), and soil aggregate stability of peach (Prunus persica), walnut (Juglans regia L.), and apple (Malus pumila) orchards, black locust (Robinia pseudoacacia), and grassland of similar age on the semi-arid Loess Plateau. Forestland, especially black locust, had significantly lower SWC than grassland. The different vegetation restoration types altered the soil texture; grassland had the highest clay content, while black locust had the lowest. Afforestation promoted deep root formation, reaching>10 m, with>50 % of the roots below 2 m. Compared with grassland, forestland did not increase SOC content in the soil profile. Soil BD increased with increasing soil depth from 0 to 80 cm for the five vegetation types but was relatively stable below 80 cm; grassland had the greatest BD, while black locust had the lowest. The walnut orchard had the lowest Ks in the 0–80 cm soil layer. The apple orchard had the highest residual soil water content and field capacity. The apple orchard had significantly lower mean weight diameter (MWD) than the others, indicating low surface soil stability due to tillage management, increasing the risk of soil erosion. Overall, these results suggested that black locust had greater negative effects on soil properties than economic trees. Therefore, black locust establishment or planting density should be reduced in future vegetation restoration processes.

Ecosystem services assessment based on land use simulation: A case study in the Heihe River Basin, China

• Key ESs in arid area(water yield, soil conservation and carbon storage) were assessed. • Flus and InVEST model were integrated to reflect driving of LULC on key ESs. • Water Yield and Soil Conservation showed similar regularities of distribution. • The risk of water and soil erosion may increase in the southern HRB. • Farmland degradation and urbanization may lead to a sharp decrease of WY and SC. Land use and land cover (LULC) changes exert large impacts on key ecosystem services (ESs) in arid areas. This study presents a framework to link LULC change with spatial changes in 3 key ESs in arid areas; this framework can contribute to sustainable ecological environment zoning management. In this study, taking the Heihe River Basin (HRB) as an example, we first assessed the spatiotemporal changes in 3 ESs, including soil conservation (SC), water yield (WY), and carbon storage (CS), from 1995 to 2020 using the InVEST model. Second, we used the (Future Land Use Simulation) FLUS model to predict future land-use variations in 2030 and 2050 under 4 scenarios (Basic Scenario (BS), Low-impact Scenario (LIS), High-impact Scenario (HIS), and Sustainable Development Scenario (SDS)). Third, we assessed the future spatial distributions of the 3 ESs with the InVEST model based on the output raster of the FLUS model. Spatial autocorrelation analysis was applied to ecological zoning management. The results showed that from 1995 to 2020, WY decreased slightly by 0.03%, and SC decreased by 2.6%, mainly in the midstream and upstream regions of the HRB. CS presented a trend of first decreasing by 1.3% from 1995 to 2010 and then increasing by 0.5% from 2010 to 2020; this trend was distributed in the upper reaches. In 2030 and 2050, under the HIS, CS increased by 14.7% and 22.0%, respectively, while WY increased by 0.20% and 0.47%, respectively. Under the SDS, CS increased by 1.1% and 1.3%, WY decreased by 0.21% and 0.45%, and SC decreased by 3.3% and 10%.

Assessment of rainfall-induced soil erosion rate and severity analysis for prioritization of conservation measures using RUSLE and Multi-Criteria Evaluations Technique at Gidabo watershed, Rift Valley Basin, Ethiopia

Soil erosion due to rainfall is the most dominant form of land resources deterioration in many parts of the world, including Ethiopia. Hence, assessing soil rate and understanding its major drivers are vital to implementing management interventions. This study intended to assess soil erosion rate, severity analysis of hotspot areas and prioritize it using Geographic Information System (GIS) based Revised Universal Soil Loss Equation (RUSLE) and multi-criteria Evaluation analysis Methods for Gidabo watershed, Rift Valley basin, Ethiopia. The Rainfall, Soil, land use/cover, Digital Elevation Model (DEM), and support practice data were used as input parameters of this study. The result revealed that the mean annual soil loss of the watershed was 44.2 t ha−1 yr−1, and it was found to be above the tolerable soil erosion rate. The outcome indicated that 6.8% (21909.6 ha) of the watershed categorized under high to severe (>10 t ha−1 yr−1) and need urgent mitigation measures. The study also demonstrated that the upstream parts of the watershed were more threatened by soil erosion risk due to the area's steep slope and rugged landforms. Therefore, mapping erosion hotspot areas would be helpful to watershed management planner and decision makers for prioritization of watershed management plan. It is too early to say that the finding would help policymakers plan and implement erosion mitigation measures to curb land degradation and support sustainable development in the Gidabo watershed and the Rift Valley basin in general.