Major Cause Of Land Degradation Research Articles

Impacts of sand and dust storms on food production

Abstract Sand and dust storms (SDS) are common in the world’s drylands, regions that are also critically important for global food production. Agriculture is the most prevalent land use resulting in anthropogenic SDS sources, resulting in impacts on cropland and rangeland, but food production is also affected by impacts from natural SDS sources. This review assesses our knowledge of SDS impacts on all the major types of food production in terrestrial and oceanic environments, impacts that occur in all three phases of the wind erosion system: during particle entrainment, during transport, and on deposition. These effects are short term and long term, direct and indirect. Wind erosion is a major cause of land degradation and there is good evidence to indicate that the deleterious effects of SDS can reduce food production via substantially diminished yields of crops, pastures and livestock. However, it is also clear that soil dust plays an important role in major biogeochemical cycles—especially phosphorus, nitrogen and iron—with implications for the valuable environmental services provided by numerous ecosystems, both terrestrial and marine. Ultimately, these nutrients have particular significance for soil formation, ecosystem productivity and food webs on land and at sea, and hence the provision of food for human societies. Efforts to mitigate the negative impacts of SDS on the sustainability of agriculture should be balanced with an appreciation of the significance of soil dust to the Earth system.

Assessing gully erosion susceptibility dynamics using information value and hazard index methods: A case study of Agulu-Nanka watershed, Southeast Nigeria

Gully erosion is one of the major causes of land degradation leading to the loss of productive lands globally. The Benue Trough in Nigeria is plagued with the problem of gully erosion, with a myriad of natural and anthropogenic factors considered as contributory factors. In this study, quantitative and qualitative methods were combined to evaluate gully susceptibility in the Agulu-Nanka watershed located in the lower part of Benue Trough between 2000 and 2018. Landsat 7 and 8 images, Digital Elevation Model (DEM), geological, soil, and rainfall erosivity maps were used to generate the gully erosion controlling factors including vegetation cover, lithology, soil, land use/cover, slope, curvature, aspect and rainfall erosivity. Additionally, high resolution image was used to develop gully inventory map. The information value method was used evaluate the influence of various classes of gully erosion controlling factors on gully distribution in the watershed. This enabled objective derivation of weights for the various classes of these factors. Information value analysis reveal that low percentage vegetation cover (<10 %), Ameki Group lithological unit, high slope gradient (17 − 43°) and Dystric Fluvisols soil type have the highest influence on gully erosion in the watershed. Since the information value method does not consider interrelationship between factors, the rank sum technique was used to derive factor weights based on the relationship between the factors. To develop the gully susceptibility map for the Agulu-Nanka watershed for the years 2000 and 2018, the erosion controlling factors were integrated using factor class weights derived through information value and factor weights derived through rank sum method. The analysis of gully erosion hazard maps show that approximately 48 % of the watershed was under low erosion risk over the period of 18 years. Areas under moderate, high and severe erosion risk decreased from 27.45 %, 9.45 % and 0.27 % of the watershed in year 2000, to 21.30 %, 8.41 %, and 0.20 % of the watershed respectively in 2018. On the other hand, the areas under negligible erosion risk increased from 14.69 % in year 2000, to 21.26 % of the watershed in 2018. The validation of the gully erosion susceptibility map for years 2000 and 2018 using the Receiver Operating Curve (ROC) showed ROC-AUC values of 0.81 % and 0.88 % respectively suggesting good model results. While the result of study indicates that restoration efforts through afforestation is yielding some result, the minimal reduction in the size of areas under severe and high gully erosion susceptibilities indicate that additional mitigation measures need to be combined with intensified afforestation efforts to effectively combat gully erosion in the watershed.

The transition from shifting cultivation to indigenous agroforestry as nature-based solution for land restoration in the Indian Eastern Himalayas

In the Indian Eastern Himalayas, shifting cultivation has long been a major cause of land degradation. However, indigenous communities, like the Hmar, have successfully transitioned from shifting cultivation to agroforestry systems such as pineapple agroforestry, leading to land restoration and increased household incomes. Despite these positive outcomes, little is known about how soil health indicators change during this transition. Thus, the present study aimed to investigate changes in selected soil health indicators and erodibility across different age classes of pineapple agroforestry systems (<5, 5–10, 11–15, and > 15 years old) compared to shifting cultivation and nearby natural forests. Soil samples were collected from six sites, including different stages of pineapple agroforestry systems, shifting cultivation phases, and a natural forest. At each site, three (10 × 10 m) quadrats were selected, and two (1 × 1 × 1 m) vertical soil pits were dug in each quadrat, sampling soil depths from 0 to 100 cm. The transition from shifting cultivation to pineapple agroforestry improved soil organic carbon (SOC) and stratification ratios while reducing soil erodibility. SOC stocks were estimated at 182.7 Mg C/ha for natural forest land and 188.2 Mg C/ha for the cropping phase in shifting cultivation. On the other hand, estimated SOC stocks for < 5, 5–10, 11–15 and > 15 years old stands of pineapple agroforestry system were 169.7 Mg C/ha, 157.2 Mg C/ha, 168.9 Mg C/ha and 177 Mg C/ha respectively. Thus, the estimated SOC stocks under > 15 years of pineapple agroforestry were comparable with adjacent natural forest land. The stratification ratios (SR > 2) for SOC and macronutrients indicated better soil quality in the pineapple agroforestry system than in the cropped land. The clay and modified clay ratios decreased with increasing age of pineapple agroforestry stands. The highest clay ratio was recorded in the topsoil of < 5-year-old pineapple agroforestry system, indicating a greater risk of exposure to rainfall events than in natural forest land and the cropping phase in the shifting cultivation cycle. It is concluded that transitioning from shifting cultivation to a pineapple agroforestry is a nature-based solution to restore degraded lands and presents an excellent opportunity for sustainable soil health and carbon sink management.

Estimating the extent of erosion using the RUSLE coefficient for Wadi Al-Karmashiya, northeast of Wasit Province

Soil loss is a major cause of land degradation all over the world, especially in large areas of arid and semi-arid regions. The objectives of the study were to estimate the extent of erosion and soil erosion using several indicators, especially the effect of rain coefficient, soil erodibility coefficient, slope coefficient, and cover coefficient. Plant and soil conservation factors, through RUSLE laboratories, as well as employing geographical information systems to obtain results related to soil erosion in the Karmashiya Basin, as the study showed that the volume of erosion in the basin ranged between 5-265 tons/ha/year, and that the areas most affected by erosion Those extending along the waterways, especially the central and southern regions of the basin, as well as the agricultural areas spread over a diverse area of the basin’s lands, especially those that do not follow modern methods of tillage and irrigation.

Farmers’ Perceptions on Land Degradation: A Case Study in Vietnam

This study aims to investigate farmers’ perception of land degradation in Vietnam, where land degradation is concerned as one of the nation's most pressing issues. Based on survey data from 826 farmers in three representative regions of Vietnam (including Hoa Binh province in Northern region, Quang Tri province in the Central Coastal region, and Can Tho province in Southern region) conducted in 2017, the study reveals that over 85% of the respondents have observed indications of land degradation on their farms. The farmers' perceptions of land degradation indicators were influenced by regional topography. Inappropriate farming techniques, excessive chemical use, and a lack of knowledge were reported as the major causes of land degradation. Furthermore, the farmers had limited understanding of land degradation as well as the benefits of soil conservation measures. Sustainable land management adopters exhibited their better perception of land degradation and measures for land improvement compared to non-adopters. Therefore, it is crucial to increase the farmers’ perception on land degradation and the advantages of adopting sustainable land management and this should be accomplished through widespread dissemination via mass and local media in the future

Selection of Soil and Water Conservation Technologies and Native Tree Species for Rehabilitation of Degraded Arid Lands in Southeast Ethiopia

The large-scale commercial agriculture, mining, expansion of sedentary agricultural settlements, and overgrazing in Ethiopian pastoral areas have become a major cause of land degradation. Such activities reduce grazing capacities and impoverish already fragile living conditions of the pastoralists. Such an increase in land degradations necessitates urgent calls for interventions. The main objectives of this study were to select the best performing soil and water conservation technologies and native tree species to restore degraded lands of arid and semiarid conditions in Liben District of Guji Zone, Oromia Reginal State, Ethiopia. Four locally grown and locally preferred tree species, namely, Cordia africana, Acacia tortilis, Acacia goetzei, and Combretum molle, were planted in five soil and moisture conservation structures (control, half-moon, spot hoeing, mowing, and trench). The survival rate and height and root collar diameter (RCD) growth of planted tree species were collected two years after planting. A significantly higher survival rate, RCD, and height growth of planted seedlings were recorded from half-moon (52.44 ± 12.48%; 1.66 ± 0.31 cm; 51.57 ± 2.79 cm) and trench (64.00 ± 11.49%; 1.92 ± 0.27; 69.67 ± 2.62 cm) moisture conservation structures, respectively. Acacia tortilis (58.22 ± 12.38%) and Acacia goetzei (42.99 ± 8.81%) had better survival rate than Cordia africana (4.00 ± 1.91%) and Combretum molle (24.22 ± 7.34). Cordia africana attained the largest RCD (2.50 ± 0.34 cm) and height (95.83 ± 17.25 cm) growth, followed by Acacia tortilis and Acacia goetzei. It is concluded that Acacia tortilis and Acacia goetzei are better species to grow in degraded lands. The half-moon and trench moisture conservation structures have a great potential for degraded areas of the arid and semiarid conditions of Ethiopia for better tree establishment, survival, and enhanced growth thereby rehabilitation of degraded lands.

Land degradation vulnerability mapping in a west coast river basin of India using analytical hierarchy process combined machine learning models.

Assessment and modelling of land degradation are crucial for the management of natural resources and sustainable development. The current study aims to evaluate land degradation by integrating various parameters derived from remote sensing and legacy data with analytical hierarchy process (AHP) combined machine learning models for the Mandovi river basin of western India. Various land degradation conditioning factors comprising of topographical, vegetation, pedological, and climatic variables were considered. Integration of the factors was performed through weighted overlay analysis to generate the AHP-based land degradation map. The output of AHP was then used with land degradation conditioning factors to build AHP combined gradient boosting machine (AHP-GBM), random forest (AHP-RF), and support vector machine (AHP-SVM) model. The model performances were assessed through an area under the receiver operating characteristic (AUC). The AHP-RF model recorded the highest AUC (0.996) followed by AHP-SVM (0.987), AHP (0.977), and AHP-GBM (0.975). The study revealed that AHP combined with RF could significantly improve the model performance over solo AHP. High rainfall with high slopes and improper land use were the major causes of land degradation in the study area. The findings of the current study will aid the policymakers to formulate land degradation action plans through implementing appropriate soil and water conservation measures.

Land Degradation Causes, Consequences and Sustainability of the Restoration Efforts: The Case of Soro Wereda, Hadiya Zone, Southern Ethiopia

Land degradation is a global issue and it is more severe in developing countries like Ethiopia. To address the problems of land degradation in Ethiopia, many efforts have been made since 1970s. From then onwards many attempts have been made and integrated watershed management in one among these. The study was undertaken in Soro Wereda, Hadiya Zone, and SNNPR with the objective of examining land degradation causes, consequences and sustainability of the restoration efforts. In order to achieve the stated objectives, both primary and secondary data were generated by employing qualitative and quantitative methods. Systematic sampling technique was used to select 97 representative households from three kebeles. The quantitative data was analyzed by using frequency, percentage, mean and standard deviation. The qualitative data was analyzed through narration. The findings of the study showed that gully formation, stoniness of land, absence of grasses and vegetation cover, decline in crop productivity and change in soil color are the main symptoms of land degradation. The major extent of land degradation as perceived by the local people was severe. Only very few of the households opted that highly severe regarding the extent of land degradation. The major causes of land degradation in the study were soil erosion, deforestation and over cultivation. In addition, topography, overgrazing, lack of conservation methods and cultivation of marginal land were the other important causes with the certain degree of variation. The core impacts of land degradation were the declining of yield year after year, food insecurity| poverty and drought and famine. The remaining increases of inputs, malnutrition, desertification and displacement of people ranked two up to five followed by the above mentioned impacts. It is very difficult to restore the degraded land without the full participation of relevant stakeholders. The main stakeholders that participate in the restoration process include government, NGOs, farmers and DAs and each of these stakeholders have its own roles. Adopting of the participatory approach, promoting the awareness of rural communities as well as other stakeholders, management of restored land, and combining of the restoration efforts with local knowledge are core issues to the sustainability of the restoration process. In order to run the restoration efforts in sustainable way strengthening of community participation, capacity building of stakeholders, providing of incentives for those achieve the restoration process and scale up of the best practices are needed.

Prioritization of Potential Native Plants from Arabian Peninsula Based on Economic and Ecological Values: Implication for Restoration

Land degradation is one of the most important environmental problems worldwide, including in the Arabian Peninsula. In arid climatic conditions (i.e., high temperature, high evaporation, scanty rainfall and high salinity), anthropogenic factors (i.e., grazing, camping, infrastructure development, etc.) are the major causes of land degradation. Therefore, restoration of degraded lands is urgently needed to achieve sustainable development goals. Moreover, countries in the Arabian Peninsula are suffering from a lack of natural freshwater resources. Therefore, using halophytes could be an environmentally and economically viable option to overcome limited availability of fresh water by substituting the demand of portable water for irrigation as well as restoring salt-affected lands. Saline soils are common in the Arabian Peninsula, therefore, exploring the ecological and economic potential of halophytes and incorporating them in restoration projects could be a sustainable option. In this study, an attempt was made to document the uses of Arabian halophytes through a survey of the literature and prioritizing them based on their use value. Out of the 107 species studied, 4 species, namely Arthrocnemum macrostachyum (Moric.) K.Koch., Alhagi graecorum Boiss., Bassia muricata (L.) Asch. and Phragmites australis (Cav.) Trin. Ex Steud., were categorized as high priority followed by 36 species under moderate priority. However, when the priority and life form of species was considered for prioritization, three species, namely Alhagi graecorum, Arundo donax L. and Phragmites australis, ranked at the top in the priority list among perennials and Bassia muricata ranked at the top among annuals. This information could be useful for land restoration specialists to use appropriate halophyte species to achieve for different restoration objectives in salt-affected lands. However, there is a need to develop an active monitoring system that strictly concentrates on the recycling of plants that are used in phytoremediation.

Curbing land degradation and mitigating climate change in mountainous regions: a systemic review.

Human population is envisaged to continue to grow, with a tremendous contribution to land degradation and climate change. Climate change and land degradation are intertwined, thus tackling climate change means mitigating land degradation. Climate change is a worldwide problem that affects lives and livelihoods; henceforth, mitigating measures are urgently required. With their unique, rich biodiversity, mountain areas are severely sensitive to climate change and land degradation; therefore, a speedy need to curb land degradation in mountain areas is needed. The aim of this systematic review was to appraise different strategic methods used globally to minimise land degradation and sustain mountainous areas in a frequently changing climate. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was utilised in this systematic review. The Scopus data base was utilised for document search, with a selection of articles limited between the years 2012 and 2021. Only articles written in English were considered. After assessing the abstracts, 703 articles were retained for a full review, leading to the final selection of 84 articles. The results show that soil erosion, overgrazing and construction of infrastructure are major causes of land degradation. The human population increase is also an enormous contributing factor to activities leading to land degradation and climate change. A conspicuous intensification of agricultural activities is expected to continue due to rising food demand. Curbing land degradation and climate change in mountain areas can be enforced by the government through stricter regulations. However, regulations and policies must be locally initiated, instead of globally initiated, with local communities being the main stakeholders. Hence, bottom-up rather than top-down policies would encourage local communities to embrace mitigation policy initiatives.

Organic Wastes Augment the Eco-Restoration Potential of Bamboo Species on Fly Ash-Degraded Land: A Field Study

Rapid industrialization has been a major cause of land degradation and other environmental problems globally. Most energy inputs in industries depend on coal-burning power stations which release various pollutants into the environment. Among these pollutants, fly ash is a concerning pollutant for soil quality, as it occupies a voluminous area of land in India and renders it unproductive. Therefore, this work attempts to evaluate the organic amendment-facilitated bioremediation/phytoremediation of fly ash-degraded land through bamboo plantations under field conditions. Three species of bamboo, Bambusa balcooa, B. tulda, and B. bambos, were planted on fly ash dumpsite soil amended with a combined dose of pressmud and farmyard manure. Results demonstrate that after two years of plantation, all the physicochemical attributes of the degraded land were improved considerably compared to the initial observations. Although all the bamboo species exhibited promising phytoremediation potential, variations were observed in their phytoremediation mechanisms: B. balcooa was the most ideal phytostabilizer species for Cu, Zn, and Ni. B. bambos was found as an ideal phytostabilizer of Pb and Zn while B. tulda was found as a phytoextractor of Cr and Zn. Additionally, all the bamboo species sequestrated atmospheric CO2 considerably, resulting in overall environmental restoration of the degraded area; B. balcooa was the most ideal species. Moreover, B. balcooa exhibited the highest air pollution tolerance index compared to other species. This study, therefore, recommends that a comprehensive analysis of organic matter-mediated phytoremediation would assist environmental managers to formulate sustainable eco-restoration strategies, ensuring a sustainable solution to land degradation.

Land use, management and climate effects on runoff and soil loss responses in the highlands of Ethiopia

Soil erosion by water is a major cause of land degradation in the highlands of Ethiopia and anywhere else in the world, but its magnitude and variability are rarely documented across land uses and climatological conditions. The purpose of this study was to examine runoff and soil loss responses under cropland (CL) and grazing land (GL) management practices in three climatic regions of the Ethiopian highlands: semi-arid (Mayleba), dry sub-humid (Gumara), and humid (Guder). We measured runoff and soil loss using runoff plots with and without soil and water conservation (SWC) measures (trenches, stone/soil bunds [embankments] with trenches on the upslope side, and exclosure) during the rainy season (July–September). The results revealed significant variation in runoff and soil loss amounts across land uses, SWC measures, and climatic regions. At Mayleba, seasonal runoff and soil loss in control plot were far higher from GL (280 mm, 26.5 t ha−1) than from CL (108 mm, 7.0 t ha−1) largely due to lack of protective vegetation cover and soil disruption because of intense grazing. In contrast, at Gumara and Guder, seasonal soil loss values were much higher from CL (21.4–71.2 t ha−1) than from GL (0.6–24.2 t ha−1) irrespective of runoff values. This was attributed to the excessive tillage/weeding operations involved in cultivation of teff (cereal crop) at Gumara and potato at Guder. Although SWC measures (practices) substantially reduced runoff and soil loss (decreased by 23%–86%) relative to control plot, seasonal soil loss under GL uses with trenches at Mayleba (12.6 t ha−1), CL with soil bunds and trenches at Gumara (22.1 t ha−1), and Guder (21.4 t ha−1) remained higher than the average tolerable soil loss rate (10 t ha−1 year−1) proposed for the Ethiopian highlands. This suggests that SWC measures should be carefully designed and evaluated specific to land use and climatic conditions. Overall, the results of this study can help improve SWC planning in regions where land use and climate impact on soil erosion vary across geographical areas, as they do in Ethiopia and anywhere else. However, further investigation is crucial with replication of measurements over years and locations to provide more accurate information on land use, management and climate controls on hydrological and soil erosion processes.

Assessment of Runoff and Soil Loss Under Natural Vegetation Cover and Rainfall in a Semi-Arid Catchment, West Pokot County, Kenya

Soil erosion has become a major cause of land degradation with regrettable economic losses. It has affected livelihoods of many agro-pastoral communities in Arid and Semi-arid Lands (ASALs). There is need for continuous assessment of soil erosion in these areas in order to provide sufficient data on soil loss for soil resource management, conservation, and land use planning. The purpose of this study was to determine the rate of soil loss by water for soil conservation planning in West Pokot County, Kenya. Two adjacent fields with variable vegetation cover density were identified in a semi-arid catchment for runoff plot research. Vegetation cover on the fields was measured using the transect line-intercept survey method. Field 1 had 25–50% vegetation cover while field 2 had 50–75% vegetation cover. On each field, three identical erosion plots with dimensions 20 m along the slope and 10 m wide were constructed. Runoff and sediment from the plots were measured for fifteen rainfall-runoff events during the long rains season. Data was analysed using correlation analysis and linear regression methods. The results show that runoff production varied from 1.03% to 1.44% of total rain water. Soil loss from the plots was 120.3–155.5 g/ . Runoff-rainfall correlation analysis showed a significant positive relationship (r =0.9609, P&lt;0.05%) with 92.33% variance in runoff production. Soil loss had significant positive relationship with runoff (r =0.9840, P&lt;0.05%) with 96.83% variance in soil loss. The study found that runoff production and soil loss was slow in the field with dense vegetation cover. Studies project an increase in human and livestock populations in semi-arid areas. This points at possible decrease in vegetation cover and increase in the rate of soil loss by water. The study recommends development of a soil conservation and management strategy in the study area.

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

Soil erosion by water is a major cause of land degradation. Agricultural practices and many other ecological environmental problems contribute to land degradation worldwide, especially in arid and semi-arid areas. Miyun County, which is located in a mountainous region of North China, is an important natural ecological zone and surface source of drinking water for Beijing and is very vulnerable to soil erosion due to its thin soil layer and human activities. Landsat images from 2003 and 2013 were used to analyze the land-use and land-cover change (LULCC) over this period. The revised universal soil loss equation (RUSLE) model integrated with Geographic Information System (GIS) was used to quantify soil loss and to map erosion risk. In addition, the response of soil erosion to LULCC was evaluated. The results showed that the areas under cropland, forest, and water bodies increased over the study period by 66.03, 243.44, and 9.01 km2, respectively. The increase in forested land indicated that the improved ground vegetation cover was due to the implementation of active ecological measures. Between 2003 and 2013, light soil erosion increased by 587.46 km2, and extremely severe soil erosion increased by 9.57 km2. The extents of slight, moderate, severe, and very severe soil erosion, however, decreased by 8.02, 445.21, 142.69, and 1.11 km2, respectively. A total of 57.5% of land with moderate soil erosion has been converted to light soil erosion, which could be highly beneficial for the improvement of vegetation control of soil and water losses. In terms of area, forestland exhibited the greatest increase, while moderate soil erosion exhibited the greatest decrease over the study period. Land-use change led to an alteration in the intensity of soil erosion due to changes or loss of vegetation. The conversion from high intensity soil erosion to low intensity was attributed to the implementation of ecological environmental protection. The results generated from this study may be useful for planners and land-use managers to make appropriate decisions for soil conservation.

FARMERS PERCEPTIONS ON SOIL EROSION IN SEBEYA CATCHMENT, RWANDA

Soil erosion is one of the major causes of land degradation which result in low agriculture productivity. Especially, western part of Rwanda including Sebeya catchment has high susceptibility to erosion leading to huge amounts of soil loss. This study held to explore the actual status of soil erosion in Sebeya catchment. Global Information System data were used for catchment delineation. Qualitative and quantitative data were collected and analyzed. Specifically, 75 farmers living and having farm lands in the catchment were interviewed in terms of knowledge on soil erosion, causes and control measures. The results showed that streambank erosion is due to the erosive power of runoff from uplands areas with (18.7%). The main natural causes of soil erosion in Sebeya catchment are heavy rainfall (69.33%) and the slope steepness (28%). Public and private land conservation agencies should be more involved in soil management centred on farmer’s awareness and capacity building.

Assessment of Soil Erosion and Its Impact on Agricultural Productivity by Using the RMMF Model and Local Perception: A Case Study of Rangun Watershed of Mid-Hills, Nepal

Soil erosion is a major concern for the environment and natural resources leading to a serious threat to agricultural productivity and one of the major causes of land degradation in the mid-hills region of Nepal. An accurate assessment of soil erosion is needed to reduce the problem of soil loss in highly fragile mountainous areas. The present study aimed to assess spatial soil loss rate and identified risk areas and their perceived impact on agricultural productivity by using the Revised Morgan–Morgan–Finney (RMMF) model and social survey in the Rangun watershed of Dadeldhura district, Nepal. Soil erosion was assessed by using data on soil, digital elevation model, rainfall, land use, and land cover visually interpreted from multitemporal satellite images, and ILWIS 3.3 academic software was used to perform the model. A household questionnaire survey (n = 120) and focus group discussion (n = 2) in identified risk areas were carried out to understand the people’s perception towards soil erosion and its impact on agricultural productivity. The predicted average soil erosions from the forest, agriculture, and barren land were 2.7 t ha−1 yr−1, 53.73 t ha−1 yr−1, and 462.59 t ha−1 yr−1, respectively. The erosion risk area under very low to low, moderate to moderately high, and high to very high covers 92.32%, 4.96%, and 2.73%, respectively. It indicates that the rate of soil erosion was lower in forest areas, whereas it was higher in the barren land. The cropped area of the watershed has been reduced by 2.96 ha−1 yr−1, and productivity has been decreased by 0.238 t ha−1 yr−1. The impacts such as removal of topsoil (weighted mean = 4.19) and gully formation (weighted mean = 3.56) were the highest perceived factors causing productivity decline due to erosion. People perceived the impact of erosion in agricultural productivity differently ( ∗ significant at P ≤ 0.05 ). The study concluded that, comparatively, barren and agricultural lands seem more susceptible to erosion, so the long-term conservation and management investment in susceptible areas for restoration, protection, and socioeconomic support contribute significantly to land rehabilitation in the Rangun watershed.

Mapping the spatio-temporal variability of hillslope erosion with the G2 model and GIS: A case-study of the South Australian agricultural zone

Soil erosion is a major cause of land degradation globally and requires consistent and continuous monitoring methods to ensure future agricultural productivity and soil security. Therefore, tools investigating the impact and frequency of erosive events are crucial for land managers and policymakers to apply corrective measures for better erosion management in the future. Here we used the G2 erosion model to two agricultural regions of South Australia (the Eyre Peninsula and Mid-North) to predict and monitor monthly hillslope erosion. We also explored the use of a high spatio-temporal resolution rainfall product combined with other high-resolution datasets to develop a model that realistically represents the complex combination of critical drivers of erosion. The modelling outputs were used to identify the spatial and temporal variation of hillslope erosion in South Australia to support cost-effective soil and land-management strategies. The average annual hillslope erosion was relatively low, but regional erosion estimates were about three times higher for the Eyre Peninsula (0.050 t ha−1 y-1) compared to the Mid-North region (0.148 t ha−1 y-1). The Flinders Ranges and Orroroo/Carrieton Local Government Areas (LGAs) were predicted to be the most impacted by erosion between 2001 and 2017 (0.24 and 0.22 t ha−1 y-1 respectively). On the other hand, hillslope erosion estimates were very low for most of the Eyre Peninsula and the Adelaide Plains LGA. The model presented in this paper could be applied elsewhere as the input data can be downloaded through open access platforms Australia-wide, and similar datasets are available globally.

Geospatial modelling of soil erosion and risk assessment in Indian Himalayan region—A study of Uttarakhand state

Soil erosion is the major cause of land degradation, which has become a worldwide environmental problem that degrades soil productivity and water quality. Assessing soil erosion in hilly and mountainous terrain always pose a great challenge to researchers and policy makers due to the inaccessible terrain as well as the scarcity of detailed information of soil erosion factors. The study was carried out to estimate the average annual soil erosion and risk area in the Uttarakhand State of Indian Himalayan region using various high-resolution geospatial data layers such as Global rainfall erosivity database, SOILGRIDS, CartoDEM as well as LULC data by employing Revised universal soil loss equation (RUSLE) model in a GIS environment. These data layers provided spatially distributed reliable information of erosion factors. The average annual soil erosion rate was estimated as 27.45 t ha−1 yr−1, totaling to an amount of 119Mt yr−1 as potential soil loss from the state. Among the various physiographic regions, total soil loss amounts were estimated to be 2.94, 5.08, 5.35, 7.48, 15.55 and 82.88 Mt yr−1 from Tarai, Trans Himalaya, Bhabhar (foothills), Shivalik, Greater Himalaya and Middle Himalaya respectively. Mean erosion rates estimated for major river basins were found to be 14.64, 22.22, 31.23, 33.24, 36.86 and 38.00 t ha−1yr−1 for Ramganga, Ganga, Alaknanda, Kali, Bhagirathi and Yamuna basins respectively. Among the different slope classes, very steep slopes (>60%) showed the highest mean soil loss rates of 40.11 t ha−1yr−1 amounting to total soil loss of 50.28Mt yr−1. Study revealed that 20.34% of the area is classified as very severe erosion class (>40 t ha−1 yr−1). Vital information regarding regional assessment of soil erosion rate and risk area in the State highlighted the need for policy makers and planners in devising various strategies aimed at conservation and sustainable use of land resources.

A review of soil erosion modeling by R/USLE in Morocco: Achievements and limits

Soil erosion is a major cause of land degradation. It can be estimated with several models, such as empirical, conceptual and physical based. One of the empirical models used worldwide nowadays for soil erosion assessment is the Universal Soil Loss Equation (USLE) and its updated form, the Revised Universal Soil Loss Equation (RUSLE). In Morocco, this model is being used to assess and quantify soil loss by water erosion. In spite of this, it was noted that limited studies employed correctly this important tool. The goal of this review paper was to identify potential usage of R/USLE models in Morocco. This was done by evaluating the conducted studies concerning these models and main gaps and challenges were determined accordingly. Improvement options and future requirements for using R/USLE models were recommended. In order to assess the statues of the R/USLE models applications, the 56 published documents related to R/USLE models conducted in Morocco during the first use till 2020 were collected and reviewed. These publications covered five main areas. The main benefits as well as gaps of the conducted studies were discussed for each area. Current concerns, need of future studies as well as related recommendations and suggestions were also presented.

Soil quality assessment of coastal salt-affected acid soils of India

Soil salinity and acidity are some of the major causes of land degradation and have a negative impact on agricultural productivity. Assessing soil quality (SQ) of soils affected by soil salinity and acidity is required for their sustainable utilization for agricultural production. The aim of the present study was to evaluate the SQ of the salt-affected acid soils of the Indian West Coastal region using the additive and weighted soil quality indices (SQIs). The SQIs were developed using a total dataset (TDS) and a minimum dataset (MDS). The TDS comprised of 15 different soil properties as electrical conductivity (EC), pH, bulk density, soil available nitrogen (N), phosphorus (P), potassium (K), sulfur (S), boron (B), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn) and exchangeable calcium (Ca), magnesium (Mg), and sodium (Na) measured on 300 soil samples (depth 0-0.15m). Based on principal component analysis and correlation analysis, an MDS with soil properties like soil pH, EC, Na, Cu, Mn, and BD was formed. Using two approaches (additive and weighted), two datasets (TDS and MDS), and two scoring methods (linear and non-linear), eight SQIs were developed. The MDS-based linear weighted and non-linear weighted SQI found suitable to evaluate SQ of salt-affected acid soils and SQI had a significant and negative correlation of - 0.83 and - 0.70 (p < 0.01) with EC, respectively. Thus, it is clear that the SQ considerably reduces with an increase in soil salinity. The performance of the MDS-based SQIs was better than the TDS to discriminate different soil salinity classes. The agreement between the linear and non-linear scoring method of SQI had a linear relationship with a coefficient of determination (R2) of 0.91-0.96. Thus, assessing the SQ of salt-affected acid soils using MDS, linear scoring, and weighted approach of the soil quality indexing could save the time and cost involved.