Characteristics of rainfall and erosion under natural conditions of land use in semiarid regions

Abstract

The characteristics of rainfall can provide important information for management and land use may also minimize the water erosion problems. This study was carried out to evaluate soil and water loss in erosion plots with different coverage, and the interference of natural rainfall characteristics on these processes. The experiment was carried out during the rainy season in the years of 2009 and 2010, on three erosion plots, each of 20 m 2 , and under different land use conditions: native 'caatinga', thinned 'caatinga' and natural herbaceous cover. The rainfall was classified into three different rainfall patterns, characterized as early, intermediate and late. The predominant rainfall pattern for the two years under study was early rainfall with 47.6%, followed by intermediate and late with 30.5% and 22%, respectively. The smallest soil losses for the entire studied period were recorded for the native 'caatinga' plot, demonstrating the protective effect of vegetation on sediment production. Despite the early rainfall pattern being prevalent in the period of study, this was not the main factor responsible for water and soil loss.Key words: rainfall intensity, erosivity, water erosion Características das chuvas e da erosão sob condições naturais de usos do solo no semiárido RESUMO As características das chuvas podem não apenas fornecer informações importantes no que diz respeito ao uso e manejo do solo, mas também minimizar os problemas causados pela erosão hídrica. Neste sentido, objetivou-se avaliar as perdas de solo e água em parcelas de erosão com diferentes coberturas e a interferência das características das chuvas naturais nesses processos. O experimento foi conduzido durante a estação chuvosa dos anos de 2009 e 2010 em três parcelas de erosão de 20 m², submetidas a diferentes condições de uso do solo: Caatinga nativa, Caatinga raleada e cobertura herbácea natural. As chuvas foram classificadas em três diferentes padrões de precipitação caracterizados como avançado, intermediário e atrasado. O padrão de chuva predominante para os dois anos de estudo foi o avançado, com 47,6% do total de eventos, seguido pelo intermediário e atrasado com 30,5 e 22%, respectivamente. Para todo o período estudado as menores perdas de solo foram registradas na Caatinga nativa caracterizando o efeito protetor da cobertura vegetal quanto à produção de sedimentos. Apesar do padrão de chuva avançada ter sido predominante para o período estudado, este não foi o principal fator responsável pelas perdas de água e solo. Palavras-chave: intensidade das chuvas, erosividade, erosão hídricaRevista Brasileira de Engenharia Agrícola e Ambiental

Spatiotemporal variability of daily precipitation concentration and its relationship to teleconnection patterns over the Mediterranean during 1975–2015

“…Climate change is expected to substantially influence precipitation distribution and amounts (Zittis et al, 2017). Studying of temporal distribution of heavy rainfall events is very important to evaluate the amount of runoff and soil erosion and also can modify water availability, groundwater recharge and hydroelectric production (De Lima et al, 2013;Yu et al, 2018). Several studies on spatial and temporal variations of precipitation concentration have been undertaken all over the world to study the statistical structure of daily precipitation according to its concentration during the year and evaluate the heaviest precipitation events (Monjo and Martin-Vide, 2016;Yeşilırmak and Atatanir, 2016;Royé and Martin, 2017;Zheng et al, 2017;Serrano-Notivoli et al, 2018).…”

Rainfall Characterization and Sedimentological Responses of Watersheds With Different Land Uses to Precipitation in the Semiarid Region of Brazil

“…Three different groups of events were formed for the watershed RC. The formation of different groups express high temporal variability of events, which is a characteristic of the region (LIMA et al, 2013). The rainfall characteristics affected the grouping results of the watershed RC, with the rainfall in group 1 presenting lower rainfall, I30 and erosivity, however, presenting the highest average of 5-day accumulated precipitation (Table 4).…”

“…However, few studies assessed the effects of changes in land use in the Brazilian semiarid on hydrological and sedimentological processes, which cause irreparable damages, such as siltation and eutrophication of water bodies. The obtaining of a better correlation between erosivity and soil losses is limited by the high variability and low information on precipitation physical characteristics (ALBUQUERQUE et al, 2005;LIMA et al, 2013;WESTER;WASKLEWICZ;STALEY, 2014).…”

How Is the Intensity of Rainfall Events Best Characterised? A Brief Critical Review and Proposed New Rainfall Intensity Index for Application in the Study of Landsurface Processes

“…Zheng [11] intensity in relation to sheet erosion, Spain (I 30 ) Marques et al [12] rainfall-runoff relationships in cropping lands, Queensland, Australia (I 30 ) Freebairn et al [13] Brasil et al [4] Indices calculated over short time periods are to be found in many other works, including I 5 and I 15 [20]; I 5 [21]; I 10 and I 30 [22]; and I 6 , I 20 , and I 30 [23].…”