The effects of unpaved access roads on runoff and associated water quality within the Seele Estate, New Hanover, South Africa.

Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.Unpaved forestry roads can significantly affect surface runoff and sediment production, with consequential impacts for stream water quality. The potential impact of road runoff on stream water quality is mitigated by the redistribution of runoff into the forest compartments through road drains. The objective of this study was to assess runoff and the associated nutrient loads from unpaved forest access roads, and to evaluate the effectiveness of road runoff redistribution onto the forest compartments. Unpaved road segments in Mondi Forest Plantation in Seele Estate, New Hanover, South Africa were instrumented for runoff measurement in response to natural rainfall. Two road segment classes were investigated for water quality from unbounded runoff plots: steep sloped road segments of road gradients of 9.5° and 7.5°, and gentle sloped road segments of road gradients of 1.6° and 2.0°. Water quality was also assessed by monitoring road runoff, and stream water quality was analysed for water quality parameters including; pH, Nitrates, Nitrites, Phosphates, Total dissolved Oxygen, Oxygen consumption, Ammonium and temperature upstream and downstream of the Estate. The effectiveness of road runoff redistribution into the forest compartments was evaluated through relating water distribution to tree breast height diameter. Two sets of road drains corresponding to the plots of different road gradients were selected as for runoff, and sampled, and corresponding plots or allotments were established to determine tree breast height diameter measurements. The results of the study revealed that, as might have been expected, runoff production increases with the increasing road gradient. The quality of road runoff water was lower than the stream water. There were no significant differences observed in nutrient levels upstream and downstream of the road stream crossings. The nutrient concentrations however, were higher upstream of the estate than downstream. Significant differences in tree breast height diameter were noted between plots of different road gradients. This suggested that the gradient determines the infiltration of redistributed runoff and hence the availability of the water that can be used by the trees within a compartment. The results of the study suggest that unpaved roads are important in the generation of nutrient loads. Much of the nutrient value is redistributed within the compartment itself rather than being transferred to the stream. This suggests that, provided that road runoff can be contained within the compartments, the potentially negative impact of road runoff can be mitigated and may enhance tree growth

Assessing soil erosion associated with main roads in south-eastern South Africa.

Ph. D. University of KwaZulu-Natal, Pietermaritzburg 2014.Construction of linear infrastructure such as roads is increasing worldwide for the provision of efficient transportation of both humans and commodities. However, roads have been widely recognised as significant causes of increased soil erosion due to their influence on the hydrologic and geomorphic processes through the modification of natural hill-slope profiles, the construction of cut and fill embankments as well as impervious road surfaces that concentrate runoff. Accelerated soil erosion due to roads is of particular concern since the associated environmental impacts have economic ramifications related to water treatment and soil rehabilitation. In the light of the above, a better understanding of road-related soil erosion is required to guide environmentally sustainable future developments and erosion control efforts. The present study assesses soil erosion associated with main tar roads in the south-eastern region of South Africa. The first part of the study provides an overview of the linkages of roads with soil erosion by water, related structural designs that facilitate soil erosion processes as well as available approaches for assessing road-related soil erosion and the available erosion control techniques. Secondly, the study focuses on exploring the characteristics (i.e. gradient, length, and vegetation cover) of degraded and non-degraded roadcuts with a view to understanding why some roadcuts are degraded while others are not. Moreover, the study investigates the relationship between the characteristics of the roadcuts and the dimensions (i.e. width and depth) of the rills. Results show that degraded roadcuts are steeper, longer and have a lower percentage of vegetation cover when compared to non-degraded roadcuts. The results further show that there is a significant relationship between the width and depth of the rills, and the slope gradient and percentage of vegetation cover of the roadcuts. These results prompted the need to evaluate the volume of soil loss, using rill dimensions on roadcuts as well as an assessment of the relationship between the volume of soil loss and the soil properties. Results show that soil loss correlates significantly with all the rill dimensions, and the rill depth is the foremost variable in calculating rill volume than the rill width and length. In addition, the results show that there is a significant relationship between the volume of soil loss and the soil properties of the roadcuts. The study further used remotely sensed data to assess gully erosion related to road drainage release and examined the relationship between physical and climatic factors (i.e. road contributing surface area, vegetation cover, hillslope gradient and rainfall) and the volume of gullies. The results indicate that the road contributing surface area, vegetation cover and hillslope gradient have a significant contribution and influence on the size of the gullies along major armoured roads. Moreover, the results show that remote sensing technologies have the capability to investigate road-related gully erosion where detailed field work remains a challenge due to economic and time constraints. Finally, in order to evaluate the effectiveness of soil erosion control methods along the roads, the study investigates the performance of different soil erosion control methods utilised on the roadcuts. It was observed that most of the slope stabilisation methods are successful in controlling soil erosion while the majority of drainage control methods performed poorly. The results show that good performance is related to vegetation re-establishment, while poor performance may be attributed to improper application, lack of inspection and maintenance. Overall, the study provides an understanding of erosion related to the post construction phase of roads. In this regard, it is expected that the results of this study will contribute to the management of roads from the soil erosion perspective through appropriate interaction with the South African National Roads Authority (SANRAL). It is hoped that this work will lay the foundation for environmentally sustainable road construction, maintenance and the formulation of effective soil erosion control measures in the future

A Review Of Road‒Related Soil Erosion: An Assessment Of Causes, Evaluation Techniques And Available Control Measures

Road construction has increased significantly worldwide in the last decades to meet the demands of the increasing human population and this has led to serious soil erosion problems, the bulk of which is unaccounted for, especially in the developing world. For comprehensive land management decisions and monitoring strategies, a review of work that has been done to assess soil erosion due to roads is critical. This article, therefore, reviews the causes of road‒related soil erosion, assessment methods and available control measures. Specifically, work provides an overview of (i) the linkages between roads and soil erosion; (ii) measurement and prediction of road‒related erosion; and (iii) erosion control and rehabilitation techniques. Literature shows that road construction results in hill-slope profile modification; removal of vegetation cover; as well as the formation of steep slopes that are prone to severe erosion. Furthermore, there is a variety of erosion control measures for controlling road‒related erosion although no study has demonstrated the method that is cost efficient and operational across different landscapes. We are of the view that this study provides guidance in future research on road‒related soil erosion across the developing world were sophisticated monitoring techniques are limited due to resource scarcity for assessing large areas. ResumenLa construcción de carreteras se ha incrementado ampliamente en todo el mundo durante las últimas décadas para cumplir con las demandas de la creciente población humana, lo que ha llevado a serios problemas de erosión de suelos, muchos de los cuales no se previeron, especialmente, en los países en desarrollo. Sobre las decisiones y supervisión de estrategias de un manejo completo del terreno se realizó una revisión al crítico trabajo que se ha hecho para medir la erosión en suelos causados por las carreteras. Por esta razón, este artículo revisa las causas de la erosion relacionada con la construcción de rutas y evalúa los métodos y medidas de control disponibles. Específicamente, este trabajo ofrece una revisión de (a) las relaciones entre las carreteras y la erosión de los suelos; (b) la medida y la predicción de la erosión vinculada a las carreteras, y (c) las técnicas de control de erosión y rehabilitación. La literature muestra que la construcción de carreteras produce modificaciones en el perfil inclinación, remueve la vegetación superficial y aumenta la inclinación en pendientes propensas a erosión severa. Además, existen varias medidas para controlar la erosión causada por la construcción de carreteras, a pesar de que ningún estudio ha demostrado el método que sea más eficiente y operacional para diferentes paisajes. Este estudio guía futuras investigaciones en la erosion causada por la construcción de caminos en los países en desarrollo donde las técnicas de supervisión sofísticas para la evaluación de grandes áreas son limitadas debido a la escasez de recursos

Developments in the remote sensing of soil erosion in the perspective of sub-Saharan Africa. Implications on future food security and biodiversity

The remote sensing of soil erosion has gained substantial consideration, with considerable scientific research work having been conducted in the past, due to technological improvements that have resulted in the release of robust, cheap and high resolution datasets with a global foot-print. This paper reviews developments in the application of remote sensing technologies in sub-Saharan Africa with a explicit emphasis on soil erosion monitoring. Soil loss due to soil erosion by water has been identified by African geomorphologists, environmentalists and governments, as the primary threat to agriculture, biodiversity and food security across the continent. The article offers a detailed review of the progress in the remote sensing as it summarises research work that have been conducted, using various remote sensing sensors and platforms and further evaluates the significance of variations in sensor resolutions and data availability for sub-Saharan Africa. Explicit application examples are used to highlight and outline this progress. Although some progress has been made, this review has revealed the necessity for further remote sensing work to provide time-series soil erosion modelling and its implications on future food security and biodiversity in the face of changing climate and food insecurity. Overall, this review have shown the immediate need for a drastical move towards the use of new generation sensors with a plausible spatial, temporal characteristics and more importantly a global foot-print

Assessing the surface material quality of unpaved rural roads to understand susceptibility to surface deterioration. A case study of four rural areas in KwaZulu-Natal, South Africa

Road surface deterioration is one of the most common problems of unpaved road networks worldwide. It is areduction in the performance of a road due to a decline in road surface material quality. Accumulated damagefrom vehicles, environmental and physical effects may contribute to a decline in the surface material quality andhence deterioration on an unpaved road surface. This study assesses the surface material quality of unpaved ruralroads in four rural areas in the KwaZulu-Natal Province, South Africa in order to understand susceptibility tosurface deterioration. The study further establishes other possible factors such as slope gradient and rainfall, thatcould determine the surface material quality. Soil samples were collected from R3, R4, and R5 road classes infour rural areas which are: Emazabekweni, Dukuza, Mkhunya and Mhlwazini Area. Laboratory analyses wereconducted in order to determine the performance of the material as potential wearing course. Material per-formance was then determined using the Standard Methods of Testing Road Construction Materials (TMH1:1976) classification method. The results obtained imply that there is a need for better material selection duringthe construction of unpaved road networks. All road classes in Mkhunya, Emazabekweni and Mhlwazini areasexhibited grading coefficient (Gc) values less than 16 and some of the shrinkage product (Sp) values in excess of365, corresponding to a classification of Class D, A and B. These results indicate material that is susceptible toslippery conditions, easily erodible and prone to the formation of ravels and corrugations. Correlation analysisresults conducted to assess the individual relationship between measured rainfall and slope with field shrinkageproduct and grading coefficient values in each area indicated that variation in slope better explains shrinkageproduct values in each area with an R2of 0.62 when compared to rainfall producing a lower R2of 0.57. Forgrading coefficient, slope and rainfall produced similar R2of 0.65 and 0.67, respectively

Understanding the factors influencing rill erosion on roadcuts in the south eastern region of South Africa

Erosion on roadcuts is a concern due to the potential of causing environmental degradation, which has significant economic costs. It is therefore critical to understand the relationship between roadcut characteristics and soil erosion for designing roadcuts that are less vulnerable to erosion and to help road rehabilitation works. This study investigated the characteristics (i.e. gradient, length, percentage of vegetation cover and soil texture) of degraded (i.e. with rills) and non-degraded roadcuts (i.e. without rills) and explored the relationship of the roadcut characteristics with the dimensions (widths and depths) of the rills. Degraded roadcuts were steep (52.21°), long (10.70 m) and had a low percentage of vegetation cover (24.12) when compared to non-degraded roadcuts which had a gradient of 28.24°, length of 6.38 m and 91.7% of vegetation cover. Moreover, the gradient and percentage of vegetation cover of the roadcut significantly determine the rill dimensions. The widths and depths of the rills increase with the increase in slope gradient and decrease with an increase in percentage of vegetation cover. Moreover, the widths and depths of the rills decreased downslope of the roadcuts. Based on these results, re-vegetation of roadcuts as well as construction of gentle gradients could minimise rill erosion and hence the negative on-site and off-site effects

Community health workers in Lesotho: Experiences of health promotion activities

Background: Lesotho adopted primary health care in 1979, and community health workers (CHWs) were included in the programme to focus on health promotion, particularly to reach people in underserved rural areas. Although the CHW programme has been successful, the heavy burden of disease because of HIV and/or AIDS and tuberculosis shifted resources from health promotion to home-based care. Aim: The study explored the lived experience of CHWs in conducting health promotion activities in Lesotho. Setting: The study was conducted in four health centres in Berea district, Lesotho. Methods: A qualitative study was conducted using an interviewer guide translated from English into Sesotho for four CHW focus group discussions, four individual interviews of key informants and four semi-structured interviews with the health centre nurses. Results: The roles of CHWs in health promotion ranged from offering basic first aid and home-based care to increasing access to health care services by taking patients to the facilities and promoting behaviour change through health education. Their perceived successes included increased access to health care services and reduced mortality rates. CHW challenges involved their demotivation to carry out their work because of lack of or inconsistent financial incentives and supplies, work overload which compromises quality of their work and limited community involvement. Conclusion: This study concludes that CHWs are beneficial to health promotion and its various activities. They had a clear understanding of their roles and responsibilities, although they did not fully comprehend that what they were describing was, in fact, health promotion. When it came to advocacy, CHWs did not fully understand it, nor did they consider it as part of their roles, although they acknowledged its importance. Their role of increasing access to health care services by accompanying patients to the facilities has increased considerably because of changes in disease burden. This is affecting their ability to practise other health promotion activities which focus on disease prevention

Short Communication:Leucosidea sericea - control in southern Lesotho.

Tebuthiuron chemical treatments were effective in controlling Leucosidea sericea shrubs upon rangelands of the Quthing sheep stud station in southern Lesotho. Cutting treatments were also effective but more labour intensive. Repeated applications of 2,4,5-T and fire resulted in less mortality of the shrubs and lower vigour of Eragrostis chloromelas grass than Tebuthiuron treatments.Keywords: 2,4,5-t; burning; chemical control; cutting; eragrostis chloromelas; fire; grasses; lesotho; leucosidea sericea; quthing sheep stud station; rangeland; rangelands; shrubs; tebuthiuro

A Review Of Road‒Related Soil Erosion: An Assessment Of Causes, Evaluation Techniques And Available Control Measures

Road construction has increased significantly worldwide in the last decades to meet the demands of the increasing human population and this has led to serious soil erosion problems, the bulk of which is unaccounted for, especially in the developing world. For comprehensive land management decisions and monitoring strategies, a review of work that has been done to assess soil erosion due to roads is critical. This article, therefore, reviews the causes of road‒related soil erosion, assessment methods and available control measures. Specifically, work provides an overview of (i) the linkages between roads and soil erosion; (ii) measurement and prediction of road‒related erosion; and (iii) erosion control and rehabilitation techniques. Literature shows that road construction results in hill-slope profile modification; removal of vegetation cover; as well as the formation of steep slopes that are prone to severe erosion. Furthermore, there is a variety of erosion control measures for controlling road‒related erosion although no study has demonstrated the method that is cost efficient and operational across different landscapes. We are of the view that this study provides guidance in future research on road‒related soil erosion across the developing world were sophisticated monitoring techniques are limited due to resource scarcity for assessing large areas.   Resumen La construcción de carreteras se ha incrementado ampliamente en todo el mundo durante las últimas décadas para cumplir con las demandas de la creciente población humana, lo que ha llevado a serios problemas de erosión de suelos, muchos de los cuales no se previeron, especialmente, en los países en desarrollo. Sobre las decisiones y supervisión de estrategias de un manejo completo del terreno se realizó una revisión al crítico trabajo que se ha hecho para medir la erosión en suelos causados por las carreteras. Por esta razón, este artículo revisa las causas de la erosion relacionada con la construcción de rutas y evalúa los métodos y medidas de control disponibles. Específicamente, este trabajo ofrece una revisión de (a) las relaciones entre las carreteras y la erosión de los suelos; (b) la medida y la predicción de la erosión vinculada a las carreteras, y (c) las técnicas de control de erosión y rehabilitación. La literature muestra que la construcción de carreteras produce modificaciones en el perfil inclinación, remueve la vegetación superficial y aumenta la inclinación en pendientes propensas a erosión severa. Además, existen varias medidas para controlar la erosión causada por la construcción de carreteras, a pesar de que ningún estudio ha demostrado el método que sea más eficiente y operacional para diferentes paisajes. Este estudio guía futuras investigaciones en la erosion causada por la construcción de caminos en los países en desarrollo donde las técnicas de supervisión sofísticas para la evaluación de grandes áreas son limitadas debido a la escasez de recursos

Community health workers in Lesotho : experiences of health promotion activities

BACKGROUND : Lesotho adopted primary health care in 1979, and community health workers (CHWs) were included in the programme to focus on health promotion, particularly to reach people in underserved rural areas. Although the CHW programme has been successful, the heavy burden of disease because of HIV and/or AIDS and tuberculosis shifted resources from health promotion to home-based care. AIM : The study explored the lived experience of CHWs in conducting health promotion activities in Lesotho. SETTING : The study was conducted in four health centres in Berea district, Lesotho. METHODS : A qualitative study was conducted using an interviewer guide translated from English into Sesotho for four CHW focus group discussions, four individual interviews of key informants and four semi-structured interviews with the health centre nurses. RESULTS : The roles of CHWs in health promotion ranged from offering basic first aid and home-based care to increasing access to health care services by taking patients to the facilities and promoting behaviour change through health education. Their perceived successes included increased access to health care services and reduced mortality rates. CHW challenges involved their demotivation to carry out their work because of lack of or inconsistent financial incentives and supplies, work overload which compromises quality of their work and limited community involvement. CONCLUSION : This study concludes that CHWs are beneficial to health promotion and its various activities. They had a clear understanding of their roles and responsibilities, although they did not fully comprehend that what they were describing was, in fact, health promotion. When it came to advocacy, CHWs did not fully understand it, nor did they consider it as part of their roles, although they acknowledged its importance. Their role of increasing access to health care services by accompanying patients to the facilities has increased considerably because of changes in disease burden. This is affecting their ability to practise other health promotion activities which focus on disease prevention.http://www.phcfm.orgam2018School of Health Systems and Public Health (SHSPH