Vegetation plays a major role in soil protection against erosion effects,and studies have also highlighted its importance in retaining sediments from roadside slopes.Yet,hydro-sedimentological studies under natural pr...Vegetation plays a major role in soil protection against erosion effects,and studies have also highlighted its importance in retaining sediments from roadside slopes.Yet,hydro-sedimentological studies under natural precipitation conditions are still scarce in semi-arid areas due to difficulties in monitoring the few and very concentrated precipitation events.Quantifying sediment connectivity and yield at watershed scale,often highly impacted by the erosion of unpaved roads,is necessary for management plans.This study aims to evaluate the efficiency of native vegetation on roadside slope segments in Caatinga biome in retaining sediments and conserving the soil in a semi-arid area of Brazil.Surface runoff,sediment concentration,and yield measurements were measured from 34 natural precipitation events in four years on two slopes with and without vegetation.The runoff coefficients of the plot with no vegetation varied from 3.0%to 58.0%,while in the vegetated plot,they showed variation from 1.0%to 21.0%.The annual specific sediment yield ranged from 4.6 to 138.7 kg/(hm^(2)•a)for the vegetated plot and from 34.9 to 608.5 kg/(hm^(2)•a)for the unvegetated one.These results indicate a 4 to 12 times higher soil loss on the unvegetated slope in relation to the vegetated one and demonstrate that natural Caatinga vegetation acts as an effective barrier against surface-transported sediments.Moreover,natural Caatinga vegetation present on the slope plays an important role in breaking connectivity between sediment flows from unpaved roads and the watershed drainage system.These findings indicate that investments in unpaved road and roadside slope restoration,not only enhance road infrastructure but also promote environmental gains by reducing the impact of erosion.展开更多
More frequent extreme rainfall events associated with global climate change cause greater challenges for soil conservation.Severe erosion occurs on many unpaved roads since these structures create important water flow...More frequent extreme rainfall events associated with global climate change cause greater challenges for soil conservation.Severe erosion occurs on many unpaved roads since these structures create important water flow paths during heavy storms.The present research aimed to investigate the intensity and influencing factors of unpaved road erosion under varied land use and management conditions(sloping cropland,terraced cropland,forest&grass).The erosion occurred in the watersheds contributing runoff water to roads after the greatest rainfall event recorded in the mountain area of northern China caused by Typhon Lekima.The research was conducted in an agricultural-forest-dominated watershed based on field investigation and UAV-based image analysis.A road erosion level classification standard was given according to the occurrence of rills,ephemeral gullies,and gullies.Significant erosion happened on 67% of the unpaved roads;42% of them suffered moderate to severe erosion in which ephemeral gullies or gullies developed.The average erosion amount from these roads was 2280.75 t ha-1 and was significantly influenced by the watershed land use type and management.The dominant factor governing unpaved road erosion associated with terraced cropland was vegetation coverage on roads.Drainage area was the most important factor for road erosion in sloping cropland and forest&grass land,and road gradient was also a critical factor.Terraces,and forest&grass in drainage areas significantly reduced unpaved road erosion by 85%and,47%,respectively,compared to sloping cropland.More integrated measures should be used to prevent unpaved road erosion.The results of this research can be applied to road protection against erosion in heavy storms.展开更多
基金the National Council for Scientific and Technological Development (CNPq) for funding the field studies and for the research productivity fellowship (CNPq/PQ) awarded to Pedro Henrique Augusto MEDEIROS and José Carlos de ARAúJOthe Coordination for the Improvement of Higher Education Personnel (CAPES) for the doctoral scholarship awarded to Teresa Raquel Lima FARIAS (2117/13-4)the Foundation for the Support of Scientific and Technological Development in the State of Ceará (FUNCAP) for the master scholarship awarded to Maria Thereza Rocha CHAVES。
文摘Vegetation plays a major role in soil protection against erosion effects,and studies have also highlighted its importance in retaining sediments from roadside slopes.Yet,hydro-sedimentological studies under natural precipitation conditions are still scarce in semi-arid areas due to difficulties in monitoring the few and very concentrated precipitation events.Quantifying sediment connectivity and yield at watershed scale,often highly impacted by the erosion of unpaved roads,is necessary for management plans.This study aims to evaluate the efficiency of native vegetation on roadside slope segments in Caatinga biome in retaining sediments and conserving the soil in a semi-arid area of Brazil.Surface runoff,sediment concentration,and yield measurements were measured from 34 natural precipitation events in four years on two slopes with and without vegetation.The runoff coefficients of the plot with no vegetation varied from 3.0%to 58.0%,while in the vegetated plot,they showed variation from 1.0%to 21.0%.The annual specific sediment yield ranged from 4.6 to 138.7 kg/(hm^(2)•a)for the vegetated plot and from 34.9 to 608.5 kg/(hm^(2)•a)for the unvegetated one.These results indicate a 4 to 12 times higher soil loss on the unvegetated slope in relation to the vegetated one and demonstrate that natural Caatinga vegetation acts as an effective barrier against surface-transported sediments.Moreover,natural Caatinga vegetation present on the slope plays an important role in breaking connectivity between sediment flows from unpaved roads and the watershed drainage system.These findings indicate that investments in unpaved road and roadside slope restoration,not only enhance road infrastructure but also promote environmental gains by reducing the impact of erosion.
基金This research was supported by the National Natural Science Foundation of China,Grant No.41977062,SKL Foundation Grant No.A314021402-2016the Strategic Priority Research Program of the Chinese Academy of Sciences,Grant No.XDA20040202Program for Key Science and Technology Innovation Team in Shaanxi Province,Grant No.2014KCT-27.
文摘More frequent extreme rainfall events associated with global climate change cause greater challenges for soil conservation.Severe erosion occurs on many unpaved roads since these structures create important water flow paths during heavy storms.The present research aimed to investigate the intensity and influencing factors of unpaved road erosion under varied land use and management conditions(sloping cropland,terraced cropland,forest&grass).The erosion occurred in the watersheds contributing runoff water to roads after the greatest rainfall event recorded in the mountain area of northern China caused by Typhon Lekima.The research was conducted in an agricultural-forest-dominated watershed based on field investigation and UAV-based image analysis.A road erosion level classification standard was given according to the occurrence of rills,ephemeral gullies,and gullies.Significant erosion happened on 67% of the unpaved roads;42% of them suffered moderate to severe erosion in which ephemeral gullies or gullies developed.The average erosion amount from these roads was 2280.75 t ha-1 and was significantly influenced by the watershed land use type and management.The dominant factor governing unpaved road erosion associated with terraced cropland was vegetation coverage on roads.Drainage area was the most important factor for road erosion in sloping cropland and forest&grass land,and road gradient was also a critical factor.Terraces,and forest&grass in drainage areas significantly reduced unpaved road erosion by 85%and,47%,respectively,compared to sloping cropland.More integrated measures should be used to prevent unpaved road erosion.The results of this research can be applied to road protection against erosion in heavy storms.
