This study examines the relationship between gully erosion in channels, sidewalls, and interfluves, and precipitation parameters (duration, total accumulation, average intensity, and maximum intensity) annually and seasonally to determine seasonal drivers for precipitation-related erosion. Ordinary Least Square regression models of erosion using precipitation and antecedent precipitation at weekly lags of up to twelve weeks were developed for three erosion variables for each of three geomorphic areas: channels, interfluves, and sidewalls (nine models in total). Erosion was most pronounced in winter months, followed by spring, indicating the influence of high-intensity precipitation from frontal systems and repeated freeze-thaw cycles in winter; erosion in summer was driven by high-intensity precipitation from convectional storms. Annually, duration was the most important driver for erosion, however, during winter and summer months, precipitation intensity was dominant. Seasonal models retained average and maximum precipitation as drivers for erosion in winter months (dominated by frontal systems), and retained maximum precipitation intensity as a driver for erosion in summer months (dominated by convectional storms). In channels, precipitation duration was the dominant driver for erosion due to runoff-related erosion, while in sidewalls and interfluves intensity parameters were equally important as duration, likely related to rain splash erosion. These results show that the character of precipitation, which varies seasonally, is an important driver for gully erosion and that studies of precipitation-driven erosion should consider partitioning data by season to identify these drivers.

Submitted by (lucia.rodrigues@ufrpe.br) on 2016-10-06T14:19:27Z No. of bitstreams: 1 Jose Aecio Correa de Araujo.pdf: 1907020 bytes, checksum: 02c6bd046629241864e087a569410b16 (MD5) / Made available in DSpace on 2016-10-06T14:19:27Z (GMT). No. of bitstreams: 1 Jose Aecio Correa de Araujo.pdf: 1907020 bytes, checksum: 02c6bd046629241864e087a569410b16 (MD5) Previous issue date: 2013-10-04 / A subject that has aroused considerable interest in hydrometeorology and hydrology is the establishment of standards Rainstorm focusing on the positioning of the peaks over the duration of the events. We used rainfall data obtained in PCD located in the city of Barreiros in Meso coast of the state of Pernambuco, the period from 01/06/2000 (date of installation of PCD) to 31/12/2010. The methodology identified, besides the already known and referenced standards Advanced, Intermediate and Retarded, the following: Undefined and Multipico. Moreover, through the confrontation of heavy rainfall events identified with the stationary satellite images, the standards set were related to meteorological factors responsible and determinants thereof, giving bigger and better elements for aggregation of advantages in the provision of mitigation measures effects of weather forecasts and conditions within the modern view of weather. Therefore, the aim of this study was to indicate a form of rational presentation and unpublished patterns of heavy rainfall, providing subsidies to redirect the studies, with equanimity, and in accordance with the objectives which they propose, and additionally relate the patterns to weather systems that originate. / Um assunto que tem despertado bastante interesse na hidrometeorologia e hidrologia é o estabelecimento de padrões de chuvas intensas com enfoque no posicionamento dos picos ao longo da duração dos eventos. Foram usados os dados de precipitação obtidos na PCD localizada no município de Barreiros, na Mesorregião Litoral do Estado de Pernambuco, compreendendo o período de 01/06/2000 (data de instalação da PCD) a 31/12/2010. A metodologia aplicada permitiu identificar, além dos já conhecidos e referenciados padrões Avançado, Intermediário e Retardado, os seguintes: Indefinido e Multipico. Ademais, mediante a confrontação dos eventos de chuvas intensas identificados com as imagens fornecidas por satélites estacionários, os padrões estabelecidos foram relacionados com os fatores meteorológicos responsáveis e determinantes dos mesmos, conferindo maiores e melhores elementos para agregação de vantagens na provisão de medidas de mitigação dos efeitos e condições de previsões dentro da visão moderna de clima. Portanto, o objetivo do presente trabalho foi indicar uma forma de apresentação racional e inédita, dos padrões de chuvas intensas, proporcionando subsídios ao redirecionamento dos estudos, com equanimidade, e de conformidade com os objetivos a que se propõem, e, adicionalmente, relacionar os padrões aos sistemas meteorológicos que os originam.