Soil Conservation Measures Research Articles

One for all and all for one: Increasing the adaptive capacity of households and communities through a public work programme

This article uncovers the mechanisms shaping the impact of the public work component of Ethiopia’s Productive Safety Net Programme (PSNP) on beneficiaries and communities’ food security and vulnerability to various shocks. Using three waves of a national representative household survey, this study provides quantitative evidence on the pathways through which the social protection intervention affects direct beneficiaries and their community peers. The empirical findings show that the PSNP beneficiaries are less likely to be food insecure and to experience harvest losses in the aftermath of droughts. Notably, the beneficial effects of the programme partially spill over to the direct participants’ community peers. This is likely to be due the nature of the public works implemented through the programme, such as the integrated community-based watershed development, including soil and water conservation measures and rangeland management in pastoral areas. Additionally, no significant impacts have been found when households self-report stresses unrelated to droughts. Our findings are expected to inform the debate on the effectiveness of the PSNP and other adaptive social protection programmes. From a policy perspective, they suggest the explicit integration of environmental and climate considerations into the design of social protection interventions targeting poor agricultural households highly vulnerable and exposed to weather shocks.

Assessing the impacts of soil and water conservation practices on soil physicochemical properties in contrasting slope landscapes of Southern Ethiopia

In Ethiopia in general and in the study area, soil erosion, which is the main cause of land degradation, is a significant environmental and agricultural problem. The efficiency of various land management strategies used over time to reduce their detrimental effects on soil quality and health has been questioned. The purpose of this study was to determine the efficacy of soil and water management methods applied to the Offa District of the Wolaita Zone in southern Ethiopia. A total of 36 composite and core soil samples were taken from the topographies of both conserved and non-conserved fields from the top 20 cm soil depth. The collected soil data were examined using analysis of variance (ANOVA), and the mean values of the treatments were separated using the Fisher multiple range test. The results revealed that the physical and chemical properties of soil (pH, Organic carbon, Total nitrogen, Available phosphorus, Cation exchange capacity (CEC), exchangeable basic cations (Ca2+, Mg2+, K+, and Na+), Soil texture, and Bulk density showed a significance difference (p < 0.05) between the measures of soil and water conservation (SWC). The treated soils of Fanya juu, stone bund, and soil bund had the highest soil pH (6.56, 6.56, and 6.11), organic carbon (1.80, 1.62, and 1.76 %), total nitrogen (0.18, 0.16, and 0.17 %), accessible phosphorus (2.72, 2.77, and 1.94 ppm), and all exchangeable basic cations showed higher amount than untreated. The results showed that the implemented SWC structures had high value in restoring and preserving soil nutrients and improving the productive capacity of the soil. This study confirmed the effectiveness of SWC practices in improving soil quality. To achieve soil quality, it's essential to maintain awareness and use of the latest technology. It is strongly advised to highlight the urgent need for SWC training, public awareness, and government support.

Runoff Decline Is Dominated by Human Activities

Investigations into runoff change and its influencing factors hold immense significance for promoting sustainable development, efficient water resource utilization, and the improvement of the ecological environment. To reduce methodological uncertainties, this study employed six attribution analysis methods, including two statistical approaches, a Budyko equation sensitivity coefficient method, and three hydrology models, to differentiate the contributions of climate change and human activities to the runoff change in the Xiliugou basin. The results indicated an abrupt change point in 2006, and the annual runoff series from 1960 to 2020 demonstrated a significant declining trend. All the six methods revealed that human activities were the major influencing factor. The average contribution rate of climate change was noted to be 24.2%, while that of human activities was 75.8% among the six methods used for this study. The prominent human activities in the Xiliugou basin revolve around soil and water conservation measures. The research findings hold great significance for the comprehensive understanding of runoff formation and its response to the changing environment in the Xiliugou basin. Additionally, these results can provide a foundation for decision-making for water resource management and ecological protection.

Evaluating Effects of Terraces on Flow Regimes in a Hilly and Mountainous Basin

Terraces play a crucial role in regulating the water cycle. The management and restoration of, and the conservation strategies and plans for basins rely heavily on the assessment of alterations in hydrological characteristics, whether natural or man-made, within these basin systems. This study centers on evaluating the impact of terraces on temporal variations in the hydrological regime within the Laixi River basin, within the context of climate variability. To achieve this, we employed a hydrological model and applied the Indicators of Hydrologic Alteration and Range of Variability Approach (IHA–RVA). The results show that, under the influence of terraces, the annual flow exhibited an overall decreasing trend. There was a noticeable decrease in streamflow from March to July, while from October to December, there was a clear upward trend, with increases ranging from 4.76% to 8.10% at the Guanshenxindi (GSXD) and Watershed outlet (WO) cross-sections. The indicators related to the minimum flow showed an overall increasing trend, whereas all indicators related to the maximum flow exhibited a clear decreasing trend. Both high and low flow pulse counts decreased, while high and low pulse durations increased overall. The overall trend of flow reversal counts also showed a decrease. All hydrological indicators exhibited low levels of alteration, with hydrologic alteration values lower than 33.33%. However, the influence of terraces on the upstream hydrological conditions was more pronounced than their downstream effect. The terraces in the study area have played a beneficial role in the flood regulation, drought mitigation, and water resource conservation of the Laixi River. They have contributed to stabilizing the daily average flow during high flow periods and have had a positive impact on the ecological base flow during low flow periods, thereby improving the aquatic ecological environment. This study provides theoretical support for river regulation within the framework of soil and water conservation measures.

Evaluating soil erosion and determinants of farmers’ adoption of soil and water conservation measures in the Offa district, southern Ethiopia

Soil erosion is a significant environmental problem worldwide, particularly in developing countries agricultural area where it can lead to reduced soil fertility, decreased crop productivity, and even land degradation. This study explores the prevalence of soil erosion in the Wolaita area and the factors that hinder or promote the implementation of soil and water management (SWC) practices by farmers. Despite significant investment by the local government, the adoption rate of these practices remains low. Data from cross-sectional surveys were gathered from primary and secondary sources and analyzed using descriptive and inferential statistics. The study involved 378 sample households, including both adopters and non-adopters of soil and water conservation measures. A multinomial logistic regression model was utilized to investigate the factors influencing the adoption of physical conservation measures. The study found that most local farmers perceived soil erosion rates are high (43.54 %) and increasing. Some respondents had a medium perception (22.96 %) while others had a low perception (17.72 %). The results revealed that education, farm size, family size, livestock ownership, contact with extension workers, farming experiences, and land tenure security all positively and significantly influenced the adoption of conservation measures. The findings highlight the importance of sustainable conservation practices, comprehensive education and training for farmers, and the establishment of strong local institutions for credit accessibility and extension services. Additionally, fostering connections and knowledge-sharing among farm communities can enhance the adoption of soil and water conservation measures. The outcomes of this study will provide valuable insights for policymakers, researchers, and farmers to develop effective strategies to combat soil erosion and promote sustainable agriculture practices in the region. Overall, this study suggests that the local government and stakeholders must prioritize these strategies to address the critical issue of soil erosion in the Wolaita area.

Comparison of deep learning models to extract silt storage dams from remote sensing images

Determining the locations and shapes of silt storage dams (SSDs) is necessary before planning and constructing new ones or maintaining old ones. Google images with a spatial resolution of 0.54 m were cropped, labelled and enhanced to establish two schemes of remote sensing images that contain SSDs with different input and batch sizes. Five deep learning models (FCN (fully connected convolutional neural network, SegNet (deep convolutional encoder–decoder architecture for image segmentation), U-Net (convolutional networks for biomedical image segmentation), PSPNet (pyramid scene parsing network) and DeepLab-V3+) were constructed to extract SSDs from the images based on the two schemes. The loss curves, accuracies and extraction results derived from the five models were compared to identify the optimal model for SSD extraction. The results show that the overall accuracies, F1 scores and mean intersections over unions obtained from DeepLab-V3+ were, respectively, 95.29%, 70.33% and 74.13% for scheme 1 (S1) and 96.29%, 73.34% and 76.99% for scheme 2 (S2), which were better than the values for other models. PSPNet had the shortest training times (128 s/step for S1 and 348 s/step for S2). An input size of 480 × 480 pixels, a batch size of 4 and 2304 images enhanced the extraction accuracy and prevented overfitting. The results provide a reference for the planning, construction and maintenance of water and soil conservation measures.

Variation of runoff-sediment relationship at flood event scale in three typical watersheds of the Loess Plateau

River runoff and sediment load are characterized by topography, climate patterns, and vegetation in the watershed. The relationship runoff and sediment load has been greatly altered in many rivers throughout the world, as well as rivers in the Chinese Loess Plateau (LP) due to large-scale ecological restoration and soil conservation measures implementation. This study attempts to identify the changes of runoff-sediment relationship in three watersheds: the Gushanchuan River watershed, Jialu River watershed and Xichuan River watershed by using the flood event data during the periods of 1974–1989 and 2007–2019 in the LP. The results indicated that both runoff depth and sediment yield of flood events during 2007–2019 reduced significantly compared with those during 1974–1989 in all the watersheds. The highest decrease was found in the Gushanchuan River watershed, exhibiting reduction of 56.48% and 95.03% in runoff and sediment yield, respectively. The ratios between sediment yield and runoff depth in all three watersheds showed significant decrease during 2007–2019 when comparing to those in 1974–1989. The correlations between runoff and sediment variables became worse in 2007–2019, compared with those during 1974–1989. The implementation of soil and water conservation (SWC) measures (vegetation restoration, terraces and check dams) accounted for the changes in runoff-sediment relationship in all three watersheds. The result of this study could provide valuable information for the influences of SWC implementation and guide soil erosion control in the LP.

The impact of participatory action research and endogenous integrated soil fertility management on farm-gate dietary outputs in northern Tanzania

In most developing countries, although agricultural extension and research devolved since 1980s to promote relevance, cost-effectiveness, ownership, and sustainability, participatory action research (PAR) have been run, albeit with limited empirical evidence on their impacts on farmers livelihoods. The study use a three-stage extended regression model (ERM) to estimate the effect PAR and the promoted agronomic practices on crop produce dietary outputs considering potential endogenous engagement, omitted variable bias, reverse causality, endogenous covariates, and factor simultaneity. Using a sample of 607 small family farms with varying levels of research engagement in the Northern Highlands of Tanzania, the study found that PAR was associated with increased farm-gate dietary outcomes: per-capita calories, proteins, and minerals produced by 139, 216, and 143 %, respectively, and consumption of farm-produced minerals by 74–200 %. The organic manure application was associated with increased the dietary outputs by 62–113 % while the application of inorganic fertilizer with increased protein and mineral outputs by 68 and 105 %, respectively. The crop diversification was associated with increased dietary outputs by 11–25 % while pest and diseases control with increased dietary outputs by 12–17 % but with reduced consumption by 13–14 %. Soil and water conservation measures including terracing were associated with decreased dietary outputs. These findings indicate that PAR contributes to nutritional outcomes of smallholder farmers contingent on the promotion of low-cost input sources and crop diversification which can be leveraged to inform upscaling of participatory policies, strategies, and technologies.

Synergy between vegetation patterns and sedimentation has a temporal effect on water erosion in a slope‐gully system

AbstractMultiple soil and water conservation measures applied together perform better at reducing runoff and sedimentation than individual measures, which can be attributed to their synergistic effects on water erosion. However, whether these synergistic effects are always effective at reducing water erosion remains unclear. In this study, a series of physical models representing a slope‐gully system were tested to quantify the trend of synergistic effects of multi‐measure over time through simulated rainfall. The tested scenarios included four vegetation patterns on the slope—Pattern A: no grass, Pattern B: grass on the up‐slope, Pattern C: grass on the middle‐slope and Pattern D: grass on the down‐slope—and five levels of runoff path length decrease (RPLD) in the gully caused by sedimentation of a check dam (0, 1, 2, 3 and 4 m). Synergistic effects on runoff and sediment yields were influenced by vegetation patterns and RPLDs. Under the same vegetation patterns, synergistic effects increased with increase of RPLD. Under the same RPLD, the mean value of synergistic effects on runoff was in the following order: Pattern D (0.10%) &gt; Pattern C (0.09%) &gt; Pattern B (0.06%), and synergistic effects on sediment yields had a similar order: Pattern D (0.60%) &gt; Pattern C (0.42%) &gt; Pattern B (0.22%). Under Pattern B, based on the Mann–Kendall trend test, the synergistic effects on the runoff yields decreased over time. Contrastingly, under Patterns C and D, the synergistic effects on the runoff yields increased over time. The results show that the synergistic effect has time effect, and its change trend is related to vegetation patterns. Additionally, the results suggest that the middle‐ and lower‐slopes should be prioritized when restoring vegetation as the synergistic effects on runoff tend to increase when these have good vegetation cover.

Farmer’s Sagaciousness on Climate Change and Adaptation Strategies in Agriculture: A Case Study in Hyatimundaragi Village of Koppala District of Karnataka, India

Climate change is recognized as one of the leading challenges affecting the performance of agriculture and the livelihood of people. Farmers are the hardest hit as they have to continuously respond to climate variations. In order to know farmers' perception of climate change and its impacts and to identify adaptation needs semi-structured questionnaire surveys were carried out in Hyatimundaragii village of Koppala district, Karnataka. Farmers have faced climate variability and noticed increasing temperature, delayed onset of rainfall, intermittent rainfall, prolonged drought conditions, depletion of the water table, untimely filling of water bodies, increased incidence of pests and diseases, livestock diseases, and decreasing soil moisture as the critical factors affecting their cultivation, decrease yield and quality of crop produce. Some of them have started to adapt to these changes by soil conservation measures like the construction of graded bunds, mulching, green manuring and sorghum+pigeonpea intercropping, crop rotation, cultivating drought, pest and disease resistance short duration varieties, providing lifesaving irrigation to crops.

Effects of different soil and water conservation measures on plant diversity and productivity in Loess Plateau

Many soil and water conservation measures (SWCM) have been implemented in the Loess Plateau of China, and they have an impact on ecosystems all levels and involve complicated mechanisms. Previously, studies typically focused on a single factor's effect on diversity or productivity. With this background, the current investigation embarked on an extensive study, with vegetation survey conducted in the no measure plots (NM), vegetation measure plots (VM) and engineering measure plots (EM) in the Loess Plateau of China. We used structural equation models (SEM) to explain the mechanism by which SWCM affects plant productivity and diversity. VM have direct effects on plant diversity, and EM have direct effects on soil properties and community structure. The two measures also had indirect effects on plant functional traits and community structure. The results show that the changes in plant functional traits and community structure by SWCM decreased plant diversity, whereas the increase of productivity was primarily dominated by improvements in community structure, and we conclude that variability in plant diversity and productivity across different measures on the Loess Plateau was primarily due to the responses of different plants to variable soil properties and the community responses. It was also emphasized that vegetation measures were beneficial to the increase of biomass per plant, while engineering measures were more beneficial to the growth of dominant species. These findings provide a theoretical foundation for vegetation management and restoration after the application of different SWCM.

Research on environmental protection and water and soil conservation technology of power grid engineering mechanized construction based on modular design

In the construction and development of modern society, power grid engineering as an important content of urban construction and development and protection of residents' quality of life, in the face of the expanding scale of power grid investment, power grid project construction shows a rapid growth trend. With the continuous development of social economy and smart grid construction needs, the requirements of power grid construction quality and construction period are getting higher and higher. On the basis of understanding the research status of mechanized construction of power engineering, this paper mainly discusses the principle and structure of modular design by taking the actual soil and water conservation measures on site as an example, and then takes the mechanized construction of power engineering in a certain area as an example to determine the construction environmental protection technology, in order to improve the comprehensive level of China's power grid construction.

Assessing sustainable management practices of expert-introduced physical soil and water conservation measures

Soil erosion is a significant environmental and socio-economic concern. Soil and water conservation methods, guided by experts, have been developed and implemented through various channels such as government initiatives, non-governmental organizations (NGOs), and public campaigns. These efforts aim to mitigate the adverse effects of erosion. The effective maintenance of soil and water conservation measures by farmers is of paramount importance in ensuring the sustainable utilization of such measures over an extended period of time. The objective of this study was to evaluate the attitude of farmers and their implementation of sustainable management techniques regarding physical soil and water conservation measures provided by experts. Field data were obtained through the process of conducting interviews with a total of 92 households residing within a watershed that is predominantly engaged in agricultural activities. To enhance and organize home responses, the research team included key informant interviews and focus group discussions. The results of the study indicated that a significant majority of farmers (97.8%) held the perception that soil erosion was a prevailing issue. The causes of erosion were identified as frequently cultivation (21.3%), inadequate implementation of physical soil and water conservation practices (19.6%), excessive precipitation (17.9%), degradation of conservation structures (16.7%), unregulated grazing (15.3%), and deforestation (9.2%). Indigenous conservation strategies, such as the utilization of traditional diversion ditches, as well as the adoption of introduced soil and water conservation techniques like Fanya juu and soil bunds, were employed with the aim of mitigating the adverse effects of erosion. While a majority of farmers, specifically 65.2%, have adopted the improved conservation measures on their agricultural land, it is noteworthy that a significant proportion, approximately 79.3%, have not adequately maintained or repaired these imposed conservation measures. The majority of the cropland has seen substantial damage to the designed measures as a result of inadequate upkeep. The scarcity of labor and insufficient knowledge and skills provide significant constraints for farmers in effectively implementing designed conservation measures. Nevertheless, it seems that farmers are not inclined to invest their labor and financial resources in order to maintain the introduced structures, as they are mostly established through public campaigns or government/NGO incentives. Hence, it is imperative for the government and non-governmental organizations (NGOs) to allocate resources towards the promotion of awareness, policy execution, and other pertinent matters that support the long-term viability of the introduced conservation measures.

Effect of gravel coverage on the hydrodynamic characteristics of overland flow on the Loess Plateau in China

In the Loess Plateau of China, the presence of gravel mulching is widespread, and investigating the dynamic changes in hydrodynamic properties induced by gravel coverage is crucial for optimizing soil and water conservation in this region. In this study, the effect of gravel coverage on the hydrodynamic parameters characterizing the overland flow was investigated through indoor artificially simulated scouring experiments, considering ten different gravel coverages, four slope gradients, and nine flow discharges. The results demonstrated significant differences in hydrodynamic parameters under various experimental conditions (P < 0.01). The flow depth exhibited a linear increase with increasing gravel coverage. Compared to flow velocity observed on non-gravel-covered slope, the reduction percentage of flow velocity ranged from 13.62 % to 72.4 % on gravel-covered slopes. Furthermore, a prediction model was developed to quantify the impact of gravel coverage on the mean flow velocity of overland flow. The model achieved a high R2 of 0.858 and a low RME of 13.61 %. The experiments revealed that the overland flow was distributed in the “virtual laminar”-subcritical and transitional-supercritical zones, with mutual restrictions between the influence of gravel coverage and slope gradient on the flow regime. Finally, it was observed that the Darcy–Weisbach resistance coefficient increased with an increase in gravel coverage. These findings provide a solid theoretical basis for optimizing soil erosion prediction models based on the hydrodynamic characteristics of overland flow, and offer guidance for the rational allocation of soil and water conservation measures for gravel-covered slopes.

Discussion on feature enhancement technology of audit object of power transmission and transformation project settlement based on remote sensing technology

In the rapid development of social economy and science and technology, the construction management of power transmission and transformation project began to widely use modern science and technology theory, the most representative of which is remote sensing technology. According to the data obtained by UAV digital policy image and digital surface model, soil and water conservation measures and engineering prevention and control monitoring are proposed in the integrated analysis and calculation research, which can provide technical support for the construction management of power transmission and transformation projects. Therefore, on the basis of understanding the technical content of transmission and transformation engineering line construction, this paper mainly explores the transmission and transformation engineering monitoring system based on low-altitude remote sensing technology of drones and builds an intelligent transmission and transformation engineering settlement audit platform according to the current development status of transmission and transformation engineering completion settlement audit. The final practice case proves that the remote-sensing technology based power transmission and transformation project settlement audit effect is stronger, which meets the needs of power transmission and transformation project construction management in the new era.

Appraisal of Soil Conservation Practices Utilized by Crop Farmers in Orashi Region of Rivers State, Nigeria

This study investigated soil conservation practices utilized by crop farmers in Orashi Region of Rivers State consisting of Ogba/Egbema/Ndoni, Ahoada East and Ahoada West Local Government Areas. Data were collected using structured questionnaire based on 4-point Likert rating scale and interview schedule. A population sample of one hundred and twenty (120) respondents was selected to elicit information using the stratified sampling technique. Forty (40) crop farmers from each Local Government Area were selected for the study. Data were analyzed using descriptive and inferential statistics such as the arithmetic mean. Findings show that more than half (76.7%) were married and 45.8% had formal education. Majority of the respondents were within the ages of 40-49 years. The type of soil conservation practices adopted were application of manure ( =3.37), planting of cover crops ( =3.73), use of multiple cropping system ( =3.93), use of reduced tillage methods/direct seeding ( =3.83), bush fallowing ( =3.86), incorporation of crop residue ( =3.74), mulching ( =3.85), construction of bonds/other structures ( =3.93), shifting cultivation ( =3.54), and crop rotation ( =3.53). The level of adoption and utilization of the identified measures tends to agree with the farmer’s year of experience, level of awareness of soil conservation measures, age-long cultural practices or cultural barrier and technical knowhow. The study concluded that government should enact favourable agricultural policies that will enlighten farmers on soil conservation practices in their cultivation exercise. The services of extension workers will be helpful in this direction.

Estimation of Soil Loss using RUSLE, GIS, and Remote Sensing: A Case Study of Sangli District, Maharashtra

Accurate estimation of soil loss is essential for watershed managers and planners to identify the priority areas for soil and water conservation measures. This study was undertaken to estimate the average annual soil loss in the study area of Sangli district, Maharashtra by using the Revised Universal Soil Loss Equation (RUSLE) in conjunction with Geographic Information System (GIS) and Remote Sensing (RS) data. The five potential factors of RUSLE impacting soil erosion were estimated through remote sensing data, enabling a comprehensive and informed assessment of soil erosion. The results of the analysis revealed that the average annual soil loss from the study area varied between 0 t.ha-1.yr-1 and 202.10 t.ha-1.yr-1. Higher annual soil loss was estimated in the western part of the study area, which ranged from 15 t.ha-1.yr-1 to 25 t.ha-1.yr-1 as compared to other parts of the study area. The Sangali district, in general, can be categorised as a low erosion potential district (0-5 t.ha-1.yr-1). The generated information can be utilised for the implementation of soil and water management and conservation measures in the western part of Sangli district, where there is a large area under the forest and agricultural land.

Application of Geospatial Techniques in Soil Erosion Assessment in Sarbari Khad of Himachal Pradesh, India

The accurate measurement of geomorphometric parameters is crucial for assessing the condition of watersheds, particularly in mountain ecosystems and extensive areas where it can be challenging to obtain precise measurements. In this study, drainage density was used to evaluate soil erosion in the Sarbari Khad watershed located in the lesser Himalayan region of Himachal Pradesh, India, using Geographical Information System (GIS) and remotely sensed digital data. The analysis of drainage density indicated that the Sarbari Khad watershed is susceptible to surface erosion and soil degradation. The watershed was classified into low, moderate, severe, and very severe erosion categories based on the drainage density values, which revealed that about 60 percent of the area suffers from very severe erosion. The findings of this study suggest that drainage density can be used as an effective indicator for estimating erosion status of watersheds. This information can be used to prioritize watershed areas for soil and water conservation measures, which are critical for ensuring the sustainability of the watershed. Overall, this research work highlights the significance of using GIS and remotely sensed data along with direct survey-based topographical maps for assessing soil erosion in mountain ecosystems and extensive areas. The results of this study can be used to guide conservation efforts and inform policy decisions aimed at mitigating the negative impacts of soil erosion on the environment and local communities.

Identification of the Overall Slope Pit Angle Value for Erosion Control in Disposal Land

Open-pit mining can cause changes in environmental conditions, especially in disposal land. The formation of gully erosion on disposal land tends to increase as the area of open land increases. The aim of this research is to calculate the amount of erosion and the geometry of the bench terrace as a form of recommendation for reducing the rate of erosion. The methodology used is the USLE (Universal Soil Loss Equation) method approach in predicting the amount of erosion and an empirical approach in providing recommendations to reduce the rate of erosion for conservation measures in the form of bench terraces. The results showed that the erosion formed on disposal land was 123.43 tons/ha/year with a range of 60-180 tons/ha/year in the category of moderate erosion hazard. While for the dimensions of bench terraces recommended on disposal land, the overall slope pit angle value was 46,60 with a maximum single slope pit angle on the bench of 600 (16.6%). Bench dimensions in the form of bench terraces will have a major influence on the overall slope pit angle value formed. The smaller the width of the bench formed with the single slope pit angle, the greater the value of the overall slope pit angle formed. In addition to the width of the bench that affects the value of the overall slope pit angle is the height of the disposal slope. The height of the disposal slope will be directly proportional to the decrease in the overall pit angle slope, to the number of benches formed. With soil conservation measures in the form of traditional terraces in the form of bench terraces with a value factor of 0.4 in open land without vegetation, it can decrease from 123.43% (tons/ha/year) to 49.37 tons/ha/year ranging from 15-60 tons/ha/year with the category of low erosion hazard level, and or about 39% reduction in erosion that occurs.

Evaluation of the effects of grass and shrub cover on overland flow resistance and its attributes under simulated rainfall

Vegetation plays a crucial role in controlling soil erosion and regulating overland flow connectivity. However, the effects of vegetation coverage on the overland flow resistance mechanisms remain unclear. This study aimed to examine the impact of grass and shrub cover on the resistance to overland flow concerning a random patch distribution pattern. This was achieved through a series of simulated rainfall experiments. Thirty slope surfaces with different vegetation coverages, consisting of complete combinations of five grass and six shrub coverages, were tested under five rainfall intensities (60–120 mm h−1) and three slope gradients (8.75%–26.79%). The results indicated that the Darcy–Weisbach friction factor (f) values on unvegetated slopes ranged from 0.455 to 1.385, whereas those on vegetated slopes ranged from 0.500 to 5.624. Vegetation coverage increased flow resistance on hillslopes, and the relationship between f and the Reynolds number (Re) was influenced by vegetation cover and the slope gradient; thus, it showed a positive correlation when vegetation form resistance was dominant. In contrast, a negative correlation was observed. According to the t-test results, the linear superposition method had limitations in calculating overland flow resistance and was only applicable when the grass coverage was 10%. Moreover, as the coverage increased, significant differences (p < 0.05) emerged between the total resistance and the linear summation of the individual resistance components. Additional vegetation resistance plays a significant role in impeding the water flow, contributing up to 50% of the total resistance. Finally, an equation for calculating additional vegetation resistance was developed using dimensional analysis and multiple nonlinear regression. The accuracy of the equation was validated by comparing it with experimental results (NSE = 0.918, RMSE = 0.144). These findings emphasize the effectiveness of constructing grass-shrub communities and increasing vegetation coverage as measures for soil and water conservation.