Earth Roads Research Articles

Feasibility of production fired bricks based lateritic soil at very low temperature

AbstractThe present project deals with the production of lateritic soil based bricks under different curing temperatures (28°C–150°C). A fraction of 10–30 wt% amount alkaline solution was added to improve the reactive phase content. The raw materials and hardened products were characterized using X‐ray diffraction (XRD), fourrier transform infrared spectroscopy (FTIR), mechanical properties and scanning electron microscope analysis. The results show that the addition of alkaline solution (30%) and the curing temperature (150°C) have a beneficial influence on physical properties (bulk density: 1.77 g/cm3, water absorption: 16.98%, and porosity: 30.13%) and mechanical performances (flexural: 6.61 MPa and compressive: 13.57 MPa). Compared with the code requirements for stabilized earth blocks, the compressive strength was higher than the minimum required. Microstructural investigations were also carried out to confirm the macrostructural properties. The above‐mentioned process appears to be a suitable candidate for engineering applications such as the stabilization of earth roads.

Evaluation of the Structural Performance of Lime-Stabilized cubitermes sp Termite Mound Soil as a Sub-Base Layer for Sustainable Pavements

The scarcity of road materials that can be used directly in the sub-base layer of a road without preparation has led to the use of non-conventional materials. This study describes the feasibility of using hydrated lime-treated cubitermes sp termite mound soils for road construction, based on laboratory tests. Tests of Atterberg limits, dry density, CBR, compressive strength, static modulus and measurement of sinking of the material under traffic were carried out with different proportions of lime (0%, 3%, 5%, 6%, 7%, 9%). The results obtained show that the mechanical properties of soil-lime mixtures improve up to the point of lime fixation at 6% and that above 6% lime, the mechanical properties decrease. The traffic simulation at the rut shows that for the 6% lime mix, microcracks appear from 20.000 cycles and that the average settlement is 2 mm. The friction of the grains under the stresses developed by the passage of the wheel reduces the mechanical bonds of the soil-lime mixture. The rigidity of the material leads to the induced slab effect, which gives the material good behavior in hot weather, without strain or rutting. The mechanical connections during the setting of the soil-lime mixture reduce the friction of the grains under the stresses developed by the wheel. Lime welds the fines into much larger, more or less impermeable particles on the surface, which reduces the crumbling of the material by attrition, a major cause of pavement deterioration. The optimal mix can be used as a sub-base layer or wearing course for low-traffic earth roads (T1 < 300) and for the treatment of the upper parts of embankments. All these results are consolidated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses.

Multi‐stakeholder participation for successful implementation of applied research projects in Africa

Abstract Rainwater harvesting from Roads For Indigenous Pasture production and improved rural livelihoods in Kitui, Kenya (ROFIP) is an applied research project. It assessed the potential of combining multiple sustainable land management practices, for example native grass reseeding, rainwater harvesting from roads and in situ microcatchments to enhance vegetation cover in a semi‐arid dryland in Kenya. Rural earth roads were used as a catchment. Runoff generated from rainfall events was diverted into reseeded pastures with trenches established at intervals, across a slope. The ROFIP project also integrated microcatchments created using ox‐driven ploughs, a traditional practice for seedbed preparation and harnessing in situ rainwater harvesting in African drylands. Combining the diversion of runoff from roads and harvesting rainwater in situ improves and prolongs soil moisture availability in reseeded pastures. Consequently, this translated to higher biomass yields (i.e. forage for livestock) and vegetation cover (land degradation mitigation and enhanced soil health). This project clearly showed that combining rainwater harvesting and native pasture reseeding improves water retention and soil health, thus improving sustainable pasture production. However, for this to be achieved, it is prudent to involve practitioners to co‐design practical solutions that are socially, economically and environmentally sustainable. Multi‐stakeholder engagement, effective knowledge sharing, and community involvement can be major enablers in the pursuit of environmental and socioeconomic relevant benefits in applied research projects in Africa. This approach enhances a sense of shared purpose among practitioners and empowers them to become points of reference to their peers.

Establishment of flood damage function model for rural roads: A case study in the Teesta River basin, Bangladesh

Numerous studies have focused on the impact of flooding on road transportation conditions. However, a specific methodology for estimating direct damage by floods on roads considering flood and road characteristics is still missing. To bridge this gap, detailed field studies were conducted in rural Bangladesh's Teesta River Basin. The questionnaire was designed to collect information regarding flood characteristics (quantitative flood depth and qualitative flood velocity), road structure (length, width, and height above the ground), structural damage mechanism, and damaged part dimensions (length, width, and thickness) for each road segment. A flood damage function model, which considers the effects of flood factors (depth and velocity) and road characteristics (top surface material, width, and height from the ground), was created using multiple regression analysis. The consistency of this model has been examined by estimating statistical parameters, such as the Akaike information criterion, correlation coefficient, and variance inflation factor. The results showed that earth roads have suffered significant damage in contrast to Bituminous concrete (BC) roads. Less flood damage may result from a road segment that is wider but has a low height from the ground. This study can provide a straightforward model for estimating road damage for flood events in future studies.

Recent changes in the McMurdo Ice Shelf Transition Zone and Hut Point Peninsula, West Antarctica

McMurdo Ice Shelf (MIS) and Ross Island act as both lateral margins and pinning points for the Ross Ice Shelf, as well as logistic hubs for the United States and New Zealand Antarctic Programs. Recent thinning and retreat of MIS has motivated an evaluation of the future stability of this critical region and potential adaptation. If MIS were to collapse, it could initiate sizeable teleconnections across West Antarctica, as well as stifle Antarctic research that relies on MIS/Ross Island-based logistics. One logistics component already experiencing change is the Transition Zone (TZ) road, which connects MIS with the research stations on Hut Point Peninsula (HPP), Ross Island. Here we assess the vulnerability of the TZ road and a proposed rerouting location (TZ Hillside), by using a combination of in situ, remote sensing, and numerical modeling approaches. We evaluate overall elevation change by differencing late summer, WorldView-derived, DEMs (2011–2015), and evaluate the practicality of both a stable ice surface and bare earth road using a numerical ice volume flux model, informed by GPR and GPS measurements of ice thickness and velocity (2015–2016). Results show overall ice elevation change of up to 3 m, and 204 ± 24 m3 a−1 of ice flux across the TZ Hillside. Combined, these results indicate that the TZ Hillside is unsuitable for either type of road, and point to MIS terminus retreat and TZ Hillside melt as a continuing risk for TZ stability, which could prelude broader changes.

A Review: Assessment of Stabilization Dust Using Liquid Enzymes

Roads play a significant part of economic development. Due to financial constraints, in many developing countries like Botswana, there are large networks of unpaved roads. The major detriment effect of unpaved or gravel roads is dust emissions. Dust affects the climate change which in turn increases the generation of dust. This has a huge impact on human health which has risen to great concern. The best solution to mitigate dust emission from gravel roads is to seal the gravel roads but this cannot be easily achieved due to financial constraints. Traditionally, road managers have controlled dust by applying calcium chloride or magnesium chloride to the road surface. However, these salts easily leach out of the soil during precipitation events and may not be an option in environmentally sensitive areas. Bio-enzymes have emerged as environmentally friendly soil stabilizers. They are cheap and can easily be available. In this review paper the use of bio-enzymes as stabilizers and a solution to reducing dust will be reviewed, health effects of dust in this exercise to try and see if they can mitigate dust on earth roads that have been constructed using material at site or calcrete. The findings could spread the awareness of effects of dust in Botswana so that the public and private sector can help in supplying the enzymes to reduce health issues affecting the society in Botswana. It will also help decision-makers to make a wise choice of which bio-enzyme to be used effectively.

RoadVecNet: a new approach for simultaneous road network segmentation and vectorization from aerial and google earth imagery in a complex urban set-up

ABSTRACT In this study, we present a new automatic deep learning-based network named Road Vectorization Network (RoadVecNet), which comprises interlinked UNet networks to simultaneously perform road segmentation and road vectorization. Particularly, RoadVecNet contains two UNet networks. The first network with powerful representation capability can obtain more coherent and satisfactory road segmentation maps even under a complex urban set-up. The second network is linked to the first network to vectorize road networks by utilizing all of the previously generated feature maps. We utilize a loss function called focal loss weighted by median frequency balancing (MFB_FL) to focus on the hard samples, fix the training data imbalance problem, and improve the road extraction and vectorization performance. A new module named dense dilated spatial pyramid pooling, which combines the benefit of cascaded modules with atrous convolution and atrous spatial pyramid pooling, is designed to produce more scale features over a broader range. Two types of high-resolution remote sensing datasets, namely, aerial and Google Earth imagery, were used for road segmentation and road vectorization tasks. Classification results indicate that the RoadVecNet outperforms the state-of-the-art deep learning-based networks with 92.51% and 93.40% F1 score for road surface segmentation and 89.24% and 92.41% F1 score for road vectorization from the aerial and Google Earth road datasets, respectively. In addition, the proposed method outperforms the other comparative methods in terms of qualitative results and produces high-resolution road segmentation and vectorization maps. As a conclusion, the presented method demonstrates that considering topological quality may result in improvement of the final road network, which is essential in various applications, such as GIS database updating.

The Mechanical and Binding Potentials of Fresh Cow Dung (FCD) for Gravel Roads Construction

Among the developing nations, unpaved (gravel and earth) roads form a disproportionately large percentage of the road network when compared to the paved roads. For instance, in Kenya earth roads account for 47% of the road network, while the gravel roads account for about 38%. The most significant problem associated with gravel and earth roads is dust emission, which contributes to the deterioration of the road surface. In addition, the dust causes road safety, human health and the environmental quality issues. In order to minimize dust emission dust suppressants are applied annually. Dust suppressants, for example, Magnesium or Calcium Chlorides solutions are expensive and hence not widely used in developing countries like Kenya. In many Kenyan rural homes and in most African countries, fresh cow dung (FCD) is used as dust suppressants in madhouses. Therefore, this study seeks to explore the mechanical and binding potentials of FCD for gravel roads construction as a dust suppressant, improvement of mechanical and resilience properties of lateritic soils for gravel roads construction. The effect of FCD on gravel soils was determined at various percentages (0%, 3%, 6%, 9% and 12%) by weight. The Index properties, compaction properties, plasticity requirements and bearing strengths {Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR)} were determined. The results show that Maximum Dry Density (MDD) reduced while the Optimum Moisture Content (OMC) increased with the increase in dosages of FCD. The UCS test results were 257 kN/m2 (0%), 257 kN/m2 (3%), 300 kN/m2 (6%), 267 kN/m2 (9%) and 213 kN/m2 (12%) while, the CBR test results were 21%, 39%, 54%, 34%, and 24% for 0%, 3%, 6%, 9% and 12%. The research concludes that FCD at 6% by weight can be used for mechanical stabilization of gravel soils for road construction. FCD is cheaper, readily available, sustainable and environmentally friendly. This will go a long way in the economic development of low and middle-income countries.

Soil Stabilization using Pro-base Technology

Roads are the lifeline of the nation and hence a road must be of better quality which could make effective land access possible. According to a research conducted in Sri Lanka, if you want to rescue a village from poverty, 10-20 years of educational subsidy might not work, but if the same amount of money is funneled on road infrastructure development, you can see results within 2 years. An effective road network ensures efficient delivery of goods and transportation of people, directly contributing to the economic growth of the region. Due to economic reasons in developing nations like India, it is not possible to make paved roads especially in rural areas. These areas are mostly connected by the use of unpaved roads called as earth road or soil roads. But there are many problems associated in building these roads particularly like deterioration of the surface usually by rutting and formation of potholes, dusty in dry state and muddy during wet state. The basis of this report is to make aware about the non-traditional soil stabilization technique using Probase SH-85 Soil Hardener for hardening soil of any type and TX-85 Soil Stabilizer & Strengthener for stabilizing unstable soil and at last sealing it by spraying with Probase PB-65 Soil Sealant on soil surface. The Probase Road System ensures making soil road no longer dusty and muddy. These products are free from toxins and are environmental friendly unlike bitumen, soil-cement, lime and asphalt roads. Probase soil stabilizer will hence not only help in stabilizing the soil but will also reduce maintenance and construction cost, along with ensuring that the roads remain open and well operational in rainy season and dust-free in dry season that is to make it an all-weather road.

Development and Application of a Sustainable Management System for Unpaved Rural Road Networks

For the sustainable management of rural roads, social, institutional, technical, economic and environmental aspects should be considered under a long-term perspective. The current practice in developing countries is that only some of these key sustainable aspects are considered in the management process. In addition, rural roads maintenance management is commonly performed under a short-term basis, not considering the life-cycle costs and benefits in the economic analysis and project prioritization. This paper presents the development of a sustainable management system for rural road networks and its application in developing countries. The approach considers the development of a sustainable framework, application of a network-level condition evaluation methodology, condition performance models for gravel and earth roads, cost-effective maintenance standards, a long-term prioritization procedure that accounts for sustainable aspects, and a computer tool that integrates the system components. The management system has been applied and validated in two unpaved rural road networks in developing countries, located in Chile and Paraguay. Sensitivity analysis was carried out to assess the impacts of input parameters in the performance of developed system. As a result of the research an adaptable and adoptable sustainable management system for rural networks has been developed to assist local road agencies in developing countries.

Exploratory spatial analysis of traffic crashes, road mortality and morbidity in Nigeria

AbstractThis study examined the spatial distribution of road traffic crashes, mortality and morbidity in Nigeria for the period 2007–2017. The influence of exposure, road network and socio‐demographic characteristics on fatalities and injuries was analysed. Data were obtained from Federal Road Safety Corps and Annual Abstract of Statistics. Spatial statistical techniques were employed to determine the pattern of crashes, mortality and morbidity. Ordinary least squares and geographically weighted regression models were used to identify significant variables. Crashes and mortality declined by 47.9 per cent and 46.3 per cent respectively, while morbidity increased by 78.6 per cent. Crashes, mortality and morbidity were significantly clustered and high in Niger, Kaduna, FCT, Kogi and Nassarawa States. FCT recorded the highest crashes and injured persons, while Kaduna recorded the highest fatalities. Variables that significantly influenced spatial variation of mortality and morbidity were length of asphaltic concrete, surfaced dressed and earth roads, unemployment and population density. This study shows that type of road is a major factor that contributes to road crash mortality and morbidity. Crash countermeasures such as implementation of safety standards during road construction, speed reduction strategies and enforcement of seat belt use and child restraint should be implemented.

The usage of cement for soil stabilisation in construction of low volume roads in Malaysia

There are about 25% of the total road networks in Malaysia is an unpaved road which is contained gravel or earth road [1]. These are commonly referred to as the low volume roads or unpaved rural road or agriculture roads which required a very minimum standard of design and construction due the low traffic impact and function of the road as an accessibility tool to the local communities. Difficulties in transporting of the materials to the construction site due to the distance from the quarry or construction material source do occur together with the requirement of suitable machinery. Soil stabilisation was identified as an alternative method to facilitate the design and construction requirement in achieving the implementation of the project where respect to cost, time and quality. Currently, soil stabilisation method was not popular in Malaysian construction industry players especially among road designer because the conventional method of pavement design always been the most priorities. Perhaps this may due to the absence of the specification purposely for soil stabilisation works. This paper will present the Malaysian experiences of implementing cement as soil stabiliser in road construction project for rural and low volume roads. The study had been conducted in the road construction project of Jalan Pos Sinderut, Kuala Lipis, Pahang. The scope of the study covers all the stages that involved in the implementation of soil stabilisation using cement this project including design, procurement, and construction.

Rainfall induced erosion of soils used in earth roads

Earth roads in rural areas of the developing world are key engines to the development of countries. They give access to education and health services, sustain agriculture and businesses, and promote social interactions between communities. However, earth roads suffer substantially from poor engineering and funding for construction and maintenance. Rainfall is probably their most dangerous enemy resulting in soil particle detachment leading to the loss of surface material. A laboratory rainfall simulator was used to identify the performance of an earth road surface compacted at the maximum dry density against rainfall energy and surface flow. Under the rain intensity of 30mm/hr, erosion increased with rain duration from 0 to 30 minutes. Fine sand (0.06 – 0.02mm) and medium sand (0.02 – 0.6mm) particles eroded faster than coarse sand (0.6 – 2mm) and gravel (> 2mm) particles of the sediments collected at 5 minutes intervals of time. Additionally, a 20cm x 20cm photograph at the same place was analysed using ImageJ software and showed reduction in number of particles from 18554 at 10 min to 5803 at 25 min as smaller particles had eroded in the meantime.

Spatial network analysis of surface soil pollution from heavy metals and some other elements: a case study of the Baotou region of China

With the development of heavy industry, urban soil suffers serious pollution, which threatens the sustainable development of cities. Understanding the spatial distribution characteristics of surface soil pollution aids in pollution prevention and control and promotes sustainable development. We use China’s Baotou as an example. Based on the data of 2820 sampling points in main urban areas and some suburban areas of Baotou, we constructed a relationship network model for sampling points in surface soil by using the complex network method. We combined the network method with spatial geographic information to analyze the spatial agglomeration characteristics of the surface soil pollution in Baotou China. Sampling points at Dalahai Village (including 506D, 538B, and 538D) and Hayenaobao Village (including 509C, 541A, and 541C), Puerhantu Town within the Kundulun District have the most serious pollution problems, and they are all concentrated in the tailings dam. Sampling points 328D and 544A are scattered in the Leng Community, Kunhe Town, Kundulun District and Changhan Village, Haringer Township, Jiuyuan District, but they have a close co-anomaly relationship with the tailings dam. We suggest that these areas should be unified to give priority to pollution control. There is an obvious difference for Al2O3, B, Hg, and U, which are abnormal in the power plant ash storage pools, but normal at the tailings dam. Consequently, pollution control for power plant ash storage pools needs to be different from pollution control at the tailings dam. Sampling points at the Fengying Community (including 580A and 580B), Kunhe Town, Kundulun District, and Gaoyoufang Village (579D and 643B), Rare Earth Road, Qingshan District as well as other sampling points upstream of the Kundulun River have a close co-anomaly relationship with the tailings dam. It is necessary to strengthen the purification treatment of sewage upstream of the Kundulun River to reduce the spread of pollutants. These results provide a theoretical basis for the government to formulate specific cross-regional collaborative governance measures.

Исследование скорости проникновения жидкости в грунт насыпи земляного полотна

The timber road can be called one of the most significant elements of the timber industry complex, therefore, the construction of highways plays an important role not only in the effective development of the timber industry complex, but is also an indispensable element for all spheres of human activity. Considering currently available ways of transporting timber, the development of road transport becomes the most effective in the conditions of our country. Despite of this, transport infrastructure in the main forest regions is poorly developed due to the strong impact of unfavorable factors. Therefore, the paramount task for specialists is improving the quality of roads. The key problem of the majority of logging roads is the loss of strength characteristics due to the influence of unfavorable climatic conditions on them. In promising forest regions, it is expressed in strong over-moistening of soils, occurrence of floods, mudflows. The impact of floods on the surface of slopes of the earth road bed reduces its service life and leads to premature aging and deformation. Considering the rate of penetration of liquid into the soil of roadbed as a variable value, we set ourselves the goal of deriving the differential equation of fluid motion in a porous medium under the influence of external loads. When carrying out a study of the rate of penetration of liquid into the soil of the roadbed, Newton's second law was taken as the basis. Having written in more detail the values of water mass layer impregnating the surface of the earth roadbed and forces acting on the surface of the slope of the roadbed and including the force of the fluid pressure, the resistance force of the slope surface and the resistance force of the protection structure, we obtained the required equation. Using the solution of the differential equation of fluid motion in the soil of the roadbed under the influence of external loads, it is possible to determine the value of the rate of penetration of liquid into the soil of earth roadbed at different values of filtration path at any time moment.

The Reduction of the Permeability of a Lateritic Soil through the Application of Microbially Induced Calcite Precipitation

Lateritic soils are frequently utilised in tropical areas of the developing world as an engineering material in the construction of rural earth roads, usually in the form of engineered natural surface (ENS) roads. The heavy, seasonal rainfalls common to the tropics results in ENS roads becoming quickly saturated with rainwater, and no longer accessible to motorised transportation. Microbially induced calcite precipitation (MICP) has been successfully used as a treatment process to decrease the permeability of clean, cohesionless sands by studies trying to impede the movement of groundwater, and any pollutants they may contain. In order to see if MICP treatment can also reduce the susceptibility of ENS road lateritic soils to rainwater saturation, this study has treated a Brazilian sample extracted from an ENS road in Espirito do Santo, Brazil, using the MICP bacterium Sporosarcina pasteurii contained within a urea-calcium chloride solution inoculum. Investigation, by means of a Rowe cell, of the post-treatment permeability, to untreated control samples, has shown an average decrease in the vertical coefficient of permeability of 83%, from 1.15 × 10-7 m/s for the untreated control samples, to 1.92 × 10-8 m/s in treated samples.

Método de dimensionamento da espessura do revestimento das estradas de terra

No Brasil, verifica-se que grande parte da rede viária, 79,9% do total das rodovias, é composta por estradas não pavimentadas – “estradas de baixo-custo”. Observa-se que parte do orçamento de gestão da rede rodoviária do país é utilizada na manutenção rotineira dessas estradas após periodos de chuva. Entretanto, estes gastos poderão ser minimizados pela construção de uma superfície de rolamento de baixo custo, resistente tanto às intempéries da região quanto aos esforços desenvolvidos pelo tráfego. A finalidade deste trabalho é divulgar o método de dimensionamento desenvolvido pelo Programa de Assistência ao Transporte Local de Dakota do Sul, nos EUA, para determinação da espessura do revestimento primário das estradas de terra, direcionando-o ao território Brasileiro. Com base no método, o projetista, para além de obter uma significativa redução dos custos da construção destas infraestruturas, pode também estimar com maior exa ti dão as ações de reparação da seção construída, durante o ciclo de vida da estrada, priorizando a durabilidade da mesma e reduzindo os custos de manutenção.

Ecological effects of roads on the plant diversity of coastal wetland in the Yellow River Delta.

The 26 sample sites in 7 study plots adjacent to asphalt road and earth road in coastal wetland in the Yellow River Delta were selected to quantify plant diversity using quadrat sampling method in plant bloom phase of July and August 2012. The indice of β T and Jaccard's coefficient were applied to evaluate the species diversity. The results showed that the plant diversities and alien plants were high in the range of 0–20 m to the road verge. There were more exotics and halophytes in plots of asphalt roadside than that of earth roadside. However, proportion of halophytes in habitats of asphalt roadsides was lower than that of earth roadside. By comparing β-diversity, there were more common species in the asphalt roadsides than that in the earth roadsides. The similarity of plant communities in studied plots of asphalt roadsides and earth roadsides increased with increasing the distance to road verge. The effect range of roads for plant diversity in study region was about 20 m to road verge. Our results indicate that the construction and maintenance of roads in wetland could increase the plant species diversities of communities and risk of alien species invasion.

Urban development and informal drainage patterns: Gully dynamics in Southwestern Nigeria

This study evaluated the attributes of gullies in selected urban towns in part of Southwestern Nigeria. It identified the gully type and characterized them in terms of dimension and volume of eroded material. It also determined the relationship among their morphometric attributes and the factors of gully development in the study area. This was done with a view to modeling their development process. Twenty (20) towns were randomly selected for this study from where thirty (30) gully systems comprising forty (40) 1st order and five (5) 2nd order gullies were measured using Total Station (TS) and Global Positioning System (GPS) receivers for the transfer of coordinates (xyz values) to gully catchment. Google Earth images (2.5 m spatial resolution) were used to extract catchment characteristics such as area, drainage lengths, number of houses in the catchment and the impervious surface area. Soil samples taken from gully shoulders (soil tops) and floor were analyzed for textural characteristics and bulk density. Data collected was analyzed using descriptive statistics, analysis of variance, multiple regression (stepwise) and geospatial techniques. The result showed that impervious surface (X1) and bulk density (X2) contributed 89.8% (R2 = 0.898; β = 0.557; P < 0.05) to the soil loss variance in the study area. The study showed that urban gully development was largely caused by large volume of runoff on mainly steep earth roads and unpaved drains coupled with poor engineering work and drains maintenance.

Effects of Herbaceous Plants on Hydrodynamic Characters of Runoff Water, and Runoff-Yielding and Sediment-Yielding Processes on Loessial Earth-Road Surface

Runoff and soil losses from earthen hillside roads are a serious problem on the Loess Plateau in China. Indoor rainfall simulation was employed to investigate hydrodynamic characteristics of runoff water, and runoff-yielding and sediment-yielding processes on earth-road surfaces with different coverage degrees of herbaceous plants. The results indicated that on the road surfaces the Froude numbers and Reynolds Numbers of runoff fell into the category of supercritical flow of laminar flow and both of them decreased like the flow velocities and unit energy of water-carrying section with the coverage degrees of herbaceous plants increased. The Manning and Darcy-weisbach friction coefficients increased with the coverage degrees of herbaceous plants increased. On the earth-road surfaces with the different coverage degrees, runoff rates initially sharply increased and then stabilized with time and both following an offset hyperbola. With the coverage degrees increased, the infiltration rates of water into the earth roads gradually increased, but the runoff rates, sediment yield rates and sediment concentration all gradually decreased. The results revealed that on the earth-road surface herbaceous plants could play a favorable role in soil and water conservation and provided a theoretical basis for understanding the relations between herbaceous plants and soil erosion.