This report estimated the loss of life and the variation of risk level to people and properties from the city of São José do Jacuípe, at Bahia State, in Brazil, through a simulation of the dam break near the city. The simulations employ the HEC-RAS program with the HEC-GeoRAS plugin, both made available by the U.S. Army Corps of Engineers. The program is a hydrological model for the hydric flow propagation arising from the complete resolution of the Saint-Venant equation, while the plugin was used for vector editing by creating a geomorphological model from the river basin. The results from the research demonstrated that the city is exposed to a risk that is time dependent. In addition, the lack of a warning system about a possible break could cause the death of almost all residents. Otherwise, with a warning system operating, the estimation of destruction would be dramatically reduced.

Análise da distribuição espacial urbana das unidades de saúde da família e unidade básica de saúde em feira de Santana / Analysis of the urban space distribution of family health units and basic health unit in Santana fair

Purpose: This paper aims to propose the delimitation of the historic center of Feira de Santana from the identification of the initial urban fabric, since some of the old hovels were demolished and others had their facades altered. Theoretical framework: with a theoretical framework I tried to approximate geoprocessing practices with studies of historic centers. Since no work was found that studied historic centers from these remote sensing techniques. Method/design/approach: To identify the historic center, georeferencing of historic map was used as a function of the SPOT 05 image, then object-oriented (OBIA) classification was applied, since the spectral responses of old roofs differ from the roofs of newer buildings. Results and conclusion: The statistical performance of the classifier was excellent, in addition to the high spatial correlation with the historical map, based on this, it was possible to propose the delimitation of the polygonal of the historical center of the Feirense municipality, not only based on the visual interpretation, but also on the statistical parameters. Research implications: This work does not seek to exhaust the discussions regarding this historic center, but to suggest the first delimitation polygon for the municipality of Feira de Santana. Originality/value: It is intended to propose a new technique for delimiting historic centers, emphasizing that this method is not valid for all municipalities, but for those that have sociocultural characteristics similar to Feira de Santana.

É crescente a necessidade de proteção dos recursos hídricos, em especial os mananciais urbanos, uma vez que são constantemente “invadidos” pela expansão desordenada das cidades. Nesse sentido, as ferramentas de análise espacial, o sensoriamento remoto e a cartografia constituem um poderoso instrumento de avaliação dos impactos ambientais. Tais ferramentas foram exploradas nesse trabalho, cujo objetivo é realizar mapeamento multitemporal do entorno da Lagoa Grande e Lagoa da Tabua, município de Feira de Santana/BA, no período de 1975 a 2008. A escolha desse período deve-se ao fato do grande crescimento populacional, ocasionado pela industrialização do município. Para realização do trabalho foram utilizadas imagens de satélites, disponíveis pela Divisão de Geração de Imagens – DGI do Instituto Nacional de Pesquisas Espaciais – INPE, dos sensores MSS, TM do programa LANDSAT. Os procedimentos técnicos adotados na construção desse trabalho consistiram nas seguintes etapas: georreferenciamento das imagens; seleção da composição colorida, com aplicação de técnicas de realce e contraste; e classificação supervisionada, um método clássico de processamento, dando foco maior a avaliação das imagens empregadas (sazonalidade da região) e ao correlacionamento do impacto ambiental com os resultados. Foi possível, através deste método identificar alguns indicadores de desequilíbrio ambiental, como por exemplo, o avanço do espaço urbano implicando em sedimentação da Lagoa da Tabua, e na presença de Taboa, vegetação aquática comum em áreas muito poluídas na Lagoa Grande.

Purpose: The aim of this work is to carry out the morphometric characterization of the Catu River Sub-Basin, located in the municipality of Alagoinhas-BA, with the Catu River being one of the tributaries that make up the Recôncavo Norte and Inhambupe Basin - BHRN/I . Methods: Data from the ALOS Palsar radar were used to obtain the Digital Elevation Model (DEM). The processing of spatial data occurs through Geographic Information Systems (GIS), with the morphometric characteristics of the sub-basin being determined with the aid of the QuantumGIS Palmas 2.18 software. Results and discussion: The morphometric parameters were calculated, obtaining that the sub-basin has an elongated shape, relief considered wavy, little prone to flooding and 4th order classification. Research implications: The research highlights the characteristics of the sub-basin regarding the drainage network, relief and susceptibility to flooding, these factors being associated with the occupation of the region's land and the release of effluents into water bodies. Originality/value: Enables the understanding of hydrological vulnerabilities and can become support material for municipal management, as well as promoting reflection on compliance with legislation and implementation of public policies in environmental management.

This study investigated Dunnian runoff in the Sauípe River basin, Bahia, Brazil, analyzing the relationship between soil moisture, terrain slope, and land use. It utilized Landsat satellite images, annual water balance data, and rainfall data from the last 10 days. The Normalized Difference Water Index (NDWI) and Normalized Difference Vegetation Index (NDVI) were calculated, along with image classification using the Random Forest machine learning algorithm. (1) Saturated zones with potential for Dunnian runoff were identified, especially on steeper slopes, with a notable negative influence of eucalyptus on soil moisture, except in areas with steeper slopes. (2) Dunnian runoff was predominantly observed from the middle course to the mouth, following the east-west direction of the watershed. (3) Higher areas exhibited Dunnian runoff with high soil moisture values, while areas with less steep slopes showed low moisture levels. (4) The results indicate a positive correlation between steeper slopes and Dunnian runoff and a negative correlation between eucalyptus plantations and soil moisture. (5) Forest fragments exhibited high NDVI and NDWI values, suggesting dense forests with high moisture, especially in areas with steep slopes. This suggests that forest fragments are in good moisture conditions, acting to delay Dunnian runoff. (6) In areas with savannization or without vegetation, significant moisture content was not observed, indicating the absence of intense rainfall in the last ten days of image acquisition. This confirms the importance of this runoff for forest remnants.