Controlling and preventing soil erosion on slope surfaces is a pressing concern worldwide, and at the same time, there is a growing need to incorporate sustainability into our engineering works. This study evaluates the efficiency of bioengineering techniques in the development of vegetation in soil slopes located near a hydroelectric power plant in Brazil. For this purpose, twelve different bioengineering techniques were evaluated, in isolation and in combination, in the slopes (10 m high) of two experimental units (approximately 70 m long each) located next to the Paraíba do Sul riverbanks, in Brazil. High-resolution images of the slopes’ frontal view were taken in 15-day interval visits in all units for the first 90 days after implantation, followed by monthly visits up to 27 months after the works were finished. The images were treated and analyzed in a computer algorithm that, based on three-color bands (red–green–blue scale), helps to assess the temporal evolution of the vegetative cover index for each technique adopted. The results showed that most of the solutions showed a deficiency in vegetation establishment and were sensitive to climatological conditions, which induced changes in the vegetation phytosanitary aspects. Techniques which provided a satisfactory vegetative cover index throughout the investigated period are pointed out.

Vegetated swales, or bioswales, are among the most commonly used type of green infrastructure (GI) for managing stormwater in temperate climate regions. However, performance data on bioswale drainage technology applied to highly weathered soils (low fertility, high acidity, and erosion prone) in tropical and subtropical climates are still limited. Aimed at closing this gap, this research investigated the performance—assessed in terms of vegetation biomass, biodiversity and coverage of swale, the structural integrity of revetments, and erosion control potential—and cost effectiveness of five rolled erosion control products (RECPs) currently available on the market, in combination with herbaceous vegetation as the revetment of drainage swales, in tropical soils. Additionally, the research project evaluated the performance of a new preseeded RECP, the Preseeded Reinforcement Mat, for drainage in areas that are difficult to access. The performances of all six RECPs were generally adequate as bioswale revetments in the conditions investigated, with performance index values ranging from 6 to 10 in a 0 to 10 scale. At the same time, some RECPs were more conducive to the growth of regional herbaceous vegetation species, measured in terms of biodiversity, which ranged from 2 to 14 species in the different bioswales, and some were more cost effective than others, with costs ranging from 19% to 106% of the cost of concrete lined swales.

This paper aims to provide relevant results of research performed on erosion control processes at water reservoir margins under tropical conditions. This large-scale streambank erosion control study is located on the margins of the water reservoir at Volta Grande Hydroelectric Power Plant in Brazil. This reservoir lake occupies an area of 220 km2, and is located in the border of the states of Minas Gerais and São Paulo. Three experimental sites, with fast bank retreat, were identified for the implementation of these erosion control works: Pier (2,700 m2), Baia (3,524 m2), and Miguelopolis (1,280 m2), in a total study area of 7,500 m2 and length of 500 m, around the reservoir lake. Eleven different bioengineering treatment techniques, vegetated and armored techniques, were implemented on 27 parcels on these three study-areas, as follows: Straw logs and Coir logs (biologs); three metallic gabions coated with polymers and PVC-bags, box, and mattress; Polypropylene (PP) P550 geotextile; PP geotextile C350; Sintemax geotextile; MacMat geotextile; and wood crib wall. Laboratorial and field testings and measuremnents included geotechnical studies, fertility, turbidity, wind velocity, wave height, stratigraphy of the study area, and in situ permeability. All obtained geotechnical results pointed that the streambank soil is erosion prone. Collected data over a period of three years were summarized in a Performance Matrix. Turbitidy, wave height and wind velocity measurements were difficult to correlate, and could not provide much information on soil loss. Thus, to gather more data on the sediment acumulated in front of each treatment, differential bathymetry was performed and plotted by using ArcGIS map algebra. Under the studied conditions, the best biotechnical methods were armored techniques such as Gabion mattress associated with geotextile, and rip rap associated with Gabion mattress, whereas vegetated biologs and crib walls had the worst performance. Also, the use of vegetation soley was not an efficient method for controlling erosion.

Presents the studies performed to evaluate the performance of rolled erosion control products (RECPs) in the prevention of sheet erosion in a road cut slope, under simulated rain conditions. The four different covers used were: ARP 430 – vegetative screen, ARP‐440 – biotextil screen, grass mulch geotextil, control 1 (no rolled product and no vegetation), and control 2 (only grass vegetation and no rolled product). A road slope with dimensions of 47.20m in length, an average height of 7.68m and slope angle of 45° in red podzolic soil was chosen to perform this experiment, due to its edaphics and climatic similarity to most existing Brazilian road slopes found in south and south‐east regions. The erosion parameters were evaluated along the experiment for 360 days. Two simulated rains were performed at 330 days and at 360 days of the experiment. A rain intensity of 65mm/h was chosen to simulate the actual rain conditions in the area. Physical and chemical characterization, fertilization testing and erosion studies were performed to better evaluate the most appropriate conditions for vegetative growth and erosion prevention udner tropical climate conditions.

Soil erosion, transport and deposition of sediments represent invisible threats that along time can affect negatively the existing infrastructure of roads and dams, and the quality of air and water resources. In the last decades, a great number of researches were devoted to study erosion and sediments transportation processes. However, they addressed mostly areas of agriculture, water impoundments for dams, and land conservation. A lack of studies for erosion processes in urban areas is evident, in special those aiming to diminish the deposition of sediments originated from urban areas into the rivers and air, in special as airborne particulate. Traditionally, the costs associated in controlling erosion and sediments in urban areas are high and in some case, out of the range for most developing countries. Factors responsible for those high prices are the use of heavy equipments for soil grading and transportation, the use of costly building materials, and the need for employing more specialized personnel. In the case of gullies in urban areas, another concern is to ensure proper equipment access to the area for remediation operations. Hereby, it is presented a cost-effective method to recover an extensive gully erosion area of about 11,000 m 2 located in urban area. Estimated sediments released from this area to the water resources and air were estimated on about 66,000,000 tons. In this study area, bioengineering works were performed in 60 days, with hardly any sediment generated outside the work area resulting from bioengineering operations. A combination of bioengineering techniques were chosen for this study area, which was a mixture of rigid and biological products including biologs, silt fence, biodegradable straw blankets sewn with plastic threads derived from recycled PET bottles, among others. An efficient drainage system was implemented for preventing upland flow, sub-seepage and