Sensoriamento Remoto aplicado na Avaliação do Impacto do Armazenamento da Água de Chuva no Sistema de Drenagem Urbana

O processo de urbanização, com intensificação no número de construções, resulta na impermeabilização das superfícies na redução da infiltração e do escoamento subterrâneo, e consequente aumento do escoamento superficial. Neste contexto, pesquisadores buscam tecnologias para minimizar tais problemas ambientais, visando a melhoria não só da conjuntura atual, mas também das próximas gerações. Assim, se inserem as tecnologias verdes para mitigação dos problemas ambientais, com destaque para os telhados verdes. Tal cenário de crescimento urbanístico e de problemas ambientais é evidenciado nos grandes centros urbanos, a exemplo do município de Recife-PE, especificamente na Região Político Administrativa RPA2, no bairro de Dois Unidos. Para identificar áreas verdes e urbanizadas, foi empregada a tecnologia do Sensoriamento Remoto com o emprego do Índice de Construção por Diferença Normalizada (NDBI) e, para identificar os pontos baixos das vias e realizar a análise de alagamento foi utilizado o Modelo Digital de Elevação (MDE) com a geração das curvas de nível. Os resultados indicaram que as duas ações investigadas, telhados verdes e caixas d’água, conjuntamente, foram ineficientes na resolução dos alagamentos e que os custos da adaptação dos telhados para implantação das coberturas verdes foram mais onerosos que a aquisição de caixas d’água de 500 L. Por outro lado, tais ações podem contribuir para a redução das dimensões do projeto de drenagem urbana reduzindo o volume de água pluvial excedente (acima da capacidade de escoamento da sarjeta) em cerca de 45% (de 46.033,30 m3 para 20.902,23 m3). Remote Sensing applied to the Impact Assessment of Rainwater Storage in the Urban Drainage SystemA B S T R A C TThe urbanization process, with an increase in the number of constructions, results in the waterproofing of surfaces, reducing infiltration and underground runoff, and a consequent increase in surface runoff. In this context, researchers are looking for technologies to minimize such environmental problems, aiming to improve not only the current situation, but also the next generations. Thus, green technologies are included to mitigate environmental problems, with an emphasis on green roofs. Such a scenario of urban growth and environmental problems is evidenced in large urban centers, such as the municipality of Recife-PE, specifically in the Administrative Political Region RPA2, in the neighborhood of Dois Unidos. To identify green and urbanized areas, Remote Sensing technology was used with the use of the Normalized Difference Construction Index (NDBI) and, to identify the low points of the roads and perform the flood analysis, the Digital Elevation Model was used (MDE) with the generation of contour lines. The results indicated that the two actions investigated, green roofs and water tanks, together, were inefficient in resolving the floods and that the costs of adapting the roofs for the implementation of green roofs were more expensive than the purchase of water tanks from 500 L. On the other hand, such actions can contribute to reducing the dimensions of the urban drainage project by reducing the volume of excess rainwater (above the drainage capacity of the gutter) by about 45% (from 46,033.30 m3 to 20,902.23 m3).Keywords: urban drainage, green roof, water tanks.

The Role of Contour Line in Painting — an Analysis of Morandi's Still Life Painting

In painting, line is one of the basic compositional elements and an important "tool" for artists to express their ideas. The combination of line and color, composition, and shape allows the viewer to feel the author's thoughts, emotions, or distinctive thinking through the picture. Foreign cave paintings, European pre-Renaissance oil paintings and modern paintings, and domestic Dunhuang murals, silk paintings of the Warring States period and cave paintings all show that the contour line has never disappeared despite its different roles in the changing times. Therefore, the artist's generalized expression of contour lines can become a characteristic of the picture that makes the artist stand out.

Application of matlab for digital images topological characteristics calculation and analysis

The paper describes the practical results received from digital images topographic characteristics calculating in Matlab, such as length and curvature of contour lines, density of lengths and curvature, as well as irregularities of contour lines of the first and second order. Topological characteristics contain complete information about the shape and contours of a digital image, which allows them to be effectively used in solving the problems of remote sensing data processing, analysis of biomedical images, classification and pattern recognition problems.

COMPARATIVE ANALYSIS FOR METHODS OF BUILDING DIGITAL ELEVATION MODELS FROM TOPOGRAPHIC MAPS USING GEOINFORMATION TECHNOLOGIES

The article considers the question of estimating the accuracy of interpolation methods for building digital elevation models using Soviet topographic maps. The territory of the Kursk region of the Russian Federation was used as the study area, because it is located on the Central Russian Upland and characterized by the complex structure of the vertical and horizontal dissection of the relief. Contour lines automatically obtained using a Python algorithm were used as the initial elevation data to build a digital elevation model. Digital elevation models obtained by thirteen different interpolation methods in ArcGIS and Surfer software were built and analyzed. Special attention is paid to the ANUDEM method, which allows to obtain hydrologically correct digital elevation models. Recommendations for the use of one or another method of interpolation are given. The results can be useful for professionals who use topographic maps in their work and deals with the design using digital elevation models.

Large Scaled Topographic Mapping and Issues in Depicting VGI and Open Data

Open data and geospatial data collected by volunteers are nowadays easy to obtain and available with worldwide coverage through projects like OpenStreetMap. However, the use of these datasets leads to new challenges in depiction especially in the field of large scale topographic cartography. In addition to quality research, new processing and depiction methods for integrating these data are emerging. In the course of this work, specific problems of maps based on OpenStreetMap and Open Data elevation models are pointed out and possible solutions are introduced. In addition, a method for the preprocessing of contour lines is presented and the process flow is described in more detail. The goal of this work is to give insight into a toolbox of specially adapted and (semi-)automated methods. In this way, the quality standard of the depiction of topographic maps based on Open Data is to be increased, but also limitations are being shown.

Horizontal accuracy assessment of a novel algorithm for approximate a surface to a DEM

This study evaluates the horizontal positional accuracy of a new algorithm that defines a surface that approximates DEM data by means of a spline function. This algorithm allows evaluating the surface at any point in its definition domain and allows analytically estimating other parameters of interest, such as slopes, orientations, etc. To evaluate the accuracy achieved with the algorithm, we use a reference DEM 2 m × 2 m (DEMref) from which the derived DEMs are obtained at 4 m × 4 m, 8 m × 8 m and 16 m × 16 m (DEMder). For each DEMder its spline approximant is calculated, which is evaluated at the same points occupied by the DEMref cells, getting a resampled DEM 2 × 2 m (DEMrem). The horizontal accuracy is obtained by computing the area amongs the homologous contour lines derived from DEMref and DEMrem, respectively. It has been observed that the planimetric errors of the proposed algorithm are very small, even in flat areas, where you could expect major differences. Therefore, this algorithm could be used when an evaluation of the horizontal positional accuracy of a DEM product at lower resolution (DEMpro) and a different producing source than the higher resolution DEMref is wanted.

Accuracy assessment for Landsat 8 thermal bands in measuring sea surface temperature over Kuwait and North West Arabian Gulf

Studying physical oceanography is one of the important fields of remote sensing applications. Previously, the thermal mapping of seas and oceans relied on primitive methods, such as the use of sensors installed on buoys, extracting contour lines, and deriving the values from the confluence of contour lines. Today's remote sensing provides more advanced methods for extracting sea surface temperature (SST) values for all bodies of water as a continuous raster model, through thermal sensors installed on satellites designated to monitor and observe the Earth. The Landsat program has facilitated a quantum leap by providing its data free for the public. What has become increasingly important is the inclusion, in Landsat 8, of a thermal band on the TIRS sensor through which SST can be extracted with a spatial resolution of 100 m2. In this article, the accuracy of the two thermal bands (band 10 and 11) of Landsat 8 was validated in estimating the SST of Kuwaiti and Northwest Arabian Gulf waters, through the use of 62 thermal images and 66 ground-truthing points (GTPs) taken from the field in the period from July 2013 to March 2020. This was achieved through a function provided by the ENVI 5.3 software - “brightness temperature” - to derive the surface temperature. The accuracy of Landsat 8 to monitor the SST of Kuwait and north-west Arabian Gulf waters was validated by calculating the root mean square error (RMSE) and the mean absolute percentage error (MAPE). The accuracy of the thermal band 10 was ± 2.03 degrees (7.9%), while the accuracy of the thermal band 11 was ± 3.13 degrees (13.7%). Therefore, this study demonstrated that the thermal band 10 of Landsat 8 is more accurate than the thermal band 11 in monitoring the SST of Kuwaiti and north-west Arabian Gulf waters, with a difference of ± 1.1 degrees (5.8%).

Application of 3D printing in casting

The article presents the applicability of 3D printing in casting. Even complex models produced by 3D printing can be effectively applied in the field of lost pattern casting. The process was realized using Polycast and Pioneer investment powder (gypsum). Based on the measurement it is clear that the size differences come from the printing technology. The minimum wall thickness cannot be less than 0.8 mm, but there is inaccuracy under 2.1 mm when there is no infill section in the rib. More contour lines can reduce the deformation and the inaccuracy.

Construction of nearshore elevation model using open satellite data

For the tasks considering changes of water level it is required to have a combined (above water and underwater) elevation model. And the highest accuracy requirements are imposed on the parts of the model, which produce the contour lines in the range of the actual water level changes, while the information about the underwater elevation is usually very scarce and rough. In the article we consider the possibility to obtain this part of the elevation model using open high resolution (10 m/pixel) satellite images corresponding to different water levels. Here we describe the technique, which allows us to obtain the subpixel accuracy of the resulting contour lines. And we consider the problems in the quality of the satellite images that the contour lines reveal, and some ways to deal with the problems.