Influence of morphometric characteristics of the Benevente River watershed in Alfredo Chaves Municipality - Espírito Santo State

Floods affect the lives of thousands of people around the world and their causes may be related to both natural and anthropogenic factors. The objective of this study was to evaluate the relationship between the Benevente River watershed morphometry and the occurrence of floods in the town of Alfredo Chaves, Espírito Santo State, Brazil. The database consisted of a digital elevation model (ASTER), a vector hydrographic network of IBGE and a 40-year period series of daily precipitation. The morphometric parameters were obtained using Geographic Information Systems (GIS). The study area has an elongated shape, with a high drainage density, strongly undulate topography and an average slope of 42.75%. The altitude ranged from 480 to 1591 m. November, December and January were the wettest months, with a monthly average rainfall of 246.7, 261.5 and 204.2 mm, respectively. It was concluded that high slopes of the basin and of the main river, coupled with increased use and occupation of the land, exerts significant influence on the runoff in the basin, increasing the chances of the occurrence of flood peaks.

洪水灾害影响全球范围内数千民众的生计，其成因可同时涉及自然因素与人为活动因素。本研究旨在评估巴西圣埃斯皮里图州阿尔弗雷多·沙维斯镇境内本韦特河（Benevente River）流域的形态计量特征与洪水发生之间的关联。本次研究数据集包含：数字高程模型（ASTER）、巴西地理与统计研究所（IBGE）的矢量水文网络，以及一段时长40年的日降水量序列数据。研究团队借助地理信息系统（GIS）获取了流域的形态计量参数。研究区域呈长条状，河网密度较高，地形强烈起伏，平均坡度达42.75%，海拔介于480米至1591米之间。该区域降水最为丰沛的月份为11月、12月与次年1月，月均降水量分别为246.7毫米、261.5毫米与204.2毫米。研究结论表明，流域及主河道的高坡度，叠加土地开发与占用程度的加剧，会对流域径流产生显著影响，进而提升洪峰发生的概率。