Physical characterization of a watershed through GIS: a study in the Schmidt stream, Brazil

Abstract

Remote sensing and geoprocessing are essential tools for obtaining and maintaining records of human actions on space over the course of time; these tools offer the basis for diagnoses of land use, environmental interference and local development. The Schmidt stream watershed, located in the Sinos River basin, in southern Brazil, has an environmental situation similar to that of the majority of small streams draining rural and urban areas in southern Brazil: agricultural and urbanization practices do not recognize the riparian area and there is removal of original vegetation, disregarding the suitability of land use; removal of wetlands; intensive water use for various activities; and lack of control and monitoring in the discharge of wastewater, among other factors, deteriorate the quality of this important environment.This article aims to achieve a physical characterization of the Schmidt stream watershed (Sinos river basin) identifying elements such as land use and occupation, soil science, geology, climatology, extent and location of watershed, among others, so as to serve as the basis for a tool that helps in the integrated environmental management of watersheds. By applying geographic information system -GIS to the process of obtaining maps of land use and occupation, pedologicaland geological, and using climatological data from the Campo Bom meteorological station, field visit, review of literature and journals, and publicly available data, the physical characterization of the Schmidt stream watershed was performed, with a view to the integrated environmental management of this watershed. Out of the total area of the Schmidt stream watershed (23.92 km 2 ), in terms of geology, it was observed that 23.7% consist of colluvial deposits, 22.6% consist of grass facies, and 53.7% consist of Botucatu formation. Major soil types of the watershed: 97.4% Argisols and only 2.6% Planosols. Land use and occupation is characterized by wetland (0.5%), Native Forest (12.83%), Native Forest + Rural Anthropic + Secondary Vegetation + Forestry (43.81%), Urban Anthropic/Urban Area (39.85%), and also Urban Anthropic/Expansion areas (3.01%). Mean annual rainfall is 1337 mm, maximum temperatures range from 10.5°C to 41.6°C and minimum temperatures range from -1.80°C and 26°C, weak winds, occasionally over 5 m/s. Conducting an environmental assessment in this watershed is essential for environmental and land management. However, these assessments are not conducted in all watersheds and, when they are, their frequency is not sufficiency to allow for continuous monitoring, in order to model and predict scenarios, with a view to adopt medium and long-term measures for environmental protection.Keywords: land use mapping, environmental management, geographic information systems, micro basin. Caracterização física de microbacia hidrográfica através de SIG como ferramenta de apoio a gestão: um estudo no Arroio Schmidt -RS ResumoO sensoriamento remoto e geoprocessamento de imagens se constituem em ferramentas fundamentais para a ...

Vulnerabilidade Do Solo À Erosão Hídrica, Região Hidrográfica Do Guaíba-Rs

“…A bacia hidrográfica é considerada uma área constituída por um sistema de drenagem que contém uma porção de cursos d'água convergindo para o rio principal (CUIBAIANO et al, 2017). Reis et al (2015) ressaltam a importância do uso de geotecnologias para o diagnóstico ambiental, a fim de subsidiar o planejamento e gestão de recursos naturais em bacias hidrográficas, pois sendo unidades de áreas ambientais altamente sensíveis as variabilidades climáticas e intensificação do uso da terra, medidas preventivas de produtos oriundos do geoprocessamento podem minimizar os inevitáveis impactos ambientais decorrentes do avanço de ocupações de áreas urbanas e com finalidades agrícolas. Neste sentido, o objetivo deste trabalho é analisar a vulnerabilidade a erosão hídrica do solo na Região Hidrográfica do Guaíba-RS.…”

A proposal to integrate the legal definition and official delineation of watersheds in Mexico: eight model case studies

“…A hydrological basin is an area delineated by nature itself, fundamentally by the borders of surface runoff zones that converge towards a single watercourse (Reis et al, 2015). It is considered the suitable territorial unit to manage water resources, even to manage the whole environment.…”

Artificial neural network for ecological-economic zoning as a tool for spatial planning

“…In the last three decades, there has been a great increase in the availability of satellite images and of environmental and socioeconomic data, which can be used as a subsidy by the environmental sciences to understand and solve problems (Pozzebon et al, 2015;Reis et al, 2015). This increase is associated with technological development, mainly in areas linked to computing, which allows working with large amounts of data, facilitating their generation, storage, retrieval, and analysis.…”