Erosion on marginal slopes of unpaved roads in semi-arid Brazil,and the role of Caatinga vegetation in sediment retention and disconnectivity  

作　　者：Teresa Raquel Lima FARIAS Maria Thereza Rocha CHAVES Cicero Lima de ALMEIDA Pedro Henrique Augusto MEDEIROS José Carlos de ARAÚJO Joaquín NAVARRO-HEVIA 

机构地区：[1]Federal Institute of Education,Science and Technology of Ceará,Department of Civil Construction,Fortaleza 60040531,Brazil [2]Federal Institute of Education,Science and Technology of Ceará,Sobral 62042030,Brazil [3]Federal University of Ceará,Department of Agricultural Engineering,Fortaleza 60450760,Brazil [4]Agroforestry Department,University of Valladolid,Palencia 34004,Spain

出　　处：《Journal of Arid Land》2025年第4期500-514,共15页干旱区科学(英文版)

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 ARAúJO;the 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。

摘　　要：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.

关 键 词：erosion control road erosion road slopes road impact sediment retention slope restoration 

分 类 号：S157.1[农业科学—土壤学] S157[农业科学—农业基础科学]