Pub Date : 2020-04-24DOI: 10.1590/s1982-21702020000100002
G. S. Marotta
: In 2018, the Brazilian Institute of Geography and Statistics (IBGE) defined the normal height values and geopotential numbers for the High Precision Altimetric Network (HPAN), creating the need for developing procedures able to adapt works correlated with the Brazilian Geodetic System (BGS). In that context, and considering the state and municipal altimetric networks, it is necessary to estimate normal heights. To this end, this paper proposes to estimate normal height values and geopotential numbers for the Altimetric Network of the Federal District (AN-DF). Computational procedures involving the Least Squares Method were established and applied in a geometric levelling survey, which includes 200 stations distributed throughout the study area. The obtained results allowed estimating the normal heights of the network stations with accuracy up to 0.032m. However, because significant differences were found in the adjusted and known values of some used HPAN stations, we recommend a rigorous analysis of these stations before using them. In any case considering that the geometric levelling and the applied procedures were carried out correctly, it is suggested that the values estimated for all stations of the AN-DF in this work may be used. This work presents procedures adopted for adjusting, using the geometric leveling, and estimating the normal heights and geopotential numbers for stations and points that are part of the Altimetric Network of the Federal District, Brazil. The results show good accuracy of the estimated normal height values. Spatially, the accuracy increased (ranging from 0.000 m to 0.032 m) as the number of stations used as reference to compute the normal heights also increased.
{"title":"ADJUSTMENT OF A REGIONAL ALTIMETRIC NETWORK, IN BRAZIL, TO ESTIMATE NORMAL HEIGHTS AND GEOPOTENTIAL NUMBERS","authors":"G. S. Marotta","doi":"10.1590/s1982-21702020000100002","DOIUrl":"https://doi.org/10.1590/s1982-21702020000100002","url":null,"abstract":": In 2018, the Brazilian Institute of Geography and Statistics (IBGE) defined the normal height values and geopotential numbers for the High Precision Altimetric Network (HPAN), creating the need for developing procedures able to adapt works correlated with the Brazilian Geodetic System (BGS). In that context, and considering the state and municipal altimetric networks, it is necessary to estimate normal heights. To this end, this paper proposes to estimate normal height values and geopotential numbers for the Altimetric Network of the Federal District (AN-DF). Computational procedures involving the Least Squares Method were established and applied in a geometric levelling survey, which includes 200 stations distributed throughout the study area. The obtained results allowed estimating the normal heights of the network stations with accuracy up to 0.032m. However, because significant differences were found in the adjusted and known values of some used HPAN stations, we recommend a rigorous analysis of these stations before using them. In any case considering that the geometric levelling and the applied procedures were carried out correctly, it is suggested that the values estimated for all stations of the AN-DF in this work may be used. This work presents procedures adopted for adjusting, using the geometric leveling, and estimating the normal heights and geopotential numbers for stations and points that are part of the Altimetric Network of the Federal District, Brazil. The results show good accuracy of the estimated normal height values. Spatially, the accuracy increased (ranging from 0.000 m to 0.032 m) as the number of stations used as reference to compute the normal heights also increased.","PeriodicalId":55347,"journal":{"name":"Boletim De Ciencias Geodesicas","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42129031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-13DOI: 10.1590/s1982-21702019000300014
Í. O. Ferreira, Afonso de Paula dos Santos, Júlio César de Oliveira, N. G. Medeiros, Paulo César Emiliano
Currently, during the operation in shallow waters, scanning systems, such as multibeam systems, are capable of collecting thousands of points in a short time, promoting a greater coverage of the submerged bottom, with consequent increase in the detection capacity of objects. Although there has been an improvement in the accuracy of the depths collected, traditional processing, that is, manual, is still required. However, mainly due to the increased mass of data collected, manual processing has become extremely time-consuming and subjective, especially in the detection and elimination of spikes. Several algorithms are used to perform this task, but most of them are based on statistical assumptions hardly met and/or verified, such as spatial independence and normality. In this sense, the goal of this study is to present the SODA (Spatial Outlier Detection Algorithm) methodology, a new method for detection of spikes designed to treat bathymetric data collected through swath bathymetry systems. From computational simulation, promising results were obtained. SODA, in some cases, was capable to identify even 90% of spikes inserted on simulation, showing that the methodology is efficient and substantial to the bathymetric data treatment.
{"title":"ROBUST METHODOLOGY FOR DETECTION OF SPIKES IN MULTIBEAM ECHO SOUNDER DATA","authors":"Í. O. Ferreira, Afonso de Paula dos Santos, Júlio César de Oliveira, N. G. Medeiros, Paulo César Emiliano","doi":"10.1590/s1982-21702019000300014","DOIUrl":"https://doi.org/10.1590/s1982-21702019000300014","url":null,"abstract":"Currently, during the operation in shallow waters, scanning systems, such as multibeam systems, are capable of collecting thousands of points in a short time, promoting a greater coverage of the submerged bottom, with consequent increase in the detection capacity of objects. Although there has been an improvement in the accuracy of the depths collected, traditional processing, that is, manual, is still required. However, mainly due to the increased mass of data collected, manual processing has become extremely time-consuming and subjective, especially in the detection and elimination of spikes. Several algorithms are used to perform this task, but most of them are based on statistical assumptions hardly met and/or verified, such as spatial independence and normality. In this sense, the goal of this study is to present the SODA (Spatial Outlier Detection Algorithm) methodology, a new method for detection of spikes designed to treat bathymetric data collected through swath bathymetry systems. From computational simulation, promising results were obtained. SODA, in some cases, was capable to identify even 90% of spikes inserted on simulation, showing that the methodology is efficient and substantial to the bathymetric data treatment.","PeriodicalId":55347,"journal":{"name":"Boletim De Ciencias Geodesicas","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43889192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s1982-21702020000300016erratum
{"title":"Erratum: EVALUATION OF THE GNSS POSITIONING PERFORMANCE UNDER INFLUENCE OF THE IONOSPHERIC SCINTILLATION","authors":"","doi":"10.1590/s1982-21702020000300016erratum","DOIUrl":"https://doi.org/10.1590/s1982-21702020000300016erratum","url":null,"abstract":"","PeriodicalId":55347,"journal":{"name":"Boletim De Ciencias Geodesicas","volume":"68 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67565048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s1982-21702020000400020
Allan Gomes, C. P. Krueger
Abstract: Since the introduction of the Android 7 in August 2016, it has become possible to use raw data collected by GNSS sensors present in some Android smartphones and tablets. Therefore, it became possible, for the first time, to perform the post-processing of the data, which means to obtain coordinates that are more accurate than usual, from meters to decimeters. In addition, among the technological innovations in the context of positioning via smartphones, it is mentioned the use of modern GNSS sensors, like the one used by Xiaomi Mi 8, which was the first smartphone to integrate a dual-frequency GNSS sensor. In this research, data collection campaigns were carried out in static mode to evaluate the quality of geodetic coordinates obtained from Mi 8. Using freely available applications that store raw data in files in RINEX format, the data was post-processed with different positioning methods and with different software, including the freely available IBGE-PPP online service in Brazil. The results of this research show that it is possible to obtain geodetic coordinates with an accuracy at decimeter order, which indicates that the methodology can be used in some engineering applications.
{"title":"EVALUATION OF THE POSITIONAL QUALITY THROUGH THE POST-PROCESSING OF RAW GNSS DATA FROM A SMARTPHONE VIA DIFFERENT SATELLITE POSITIONING METHODS","authors":"Allan Gomes, C. P. Krueger","doi":"10.1590/s1982-21702020000400020","DOIUrl":"https://doi.org/10.1590/s1982-21702020000400020","url":null,"abstract":"Abstract: Since the introduction of the Android 7 in August 2016, it has become possible to use raw data collected by GNSS sensors present in some Android smartphones and tablets. Therefore, it became possible, for the first time, to perform the post-processing of the data, which means to obtain coordinates that are more accurate than usual, from meters to decimeters. In addition, among the technological innovations in the context of positioning via smartphones, it is mentioned the use of modern GNSS sensors, like the one used by Xiaomi Mi 8, which was the first smartphone to integrate a dual-frequency GNSS sensor. In this research, data collection campaigns were carried out in static mode to evaluate the quality of geodetic coordinates obtained from Mi 8. Using freely available applications that store raw data in files in RINEX format, the data was post-processed with different positioning methods and with different software, including the freely available IBGE-PPP online service in Brazil. The results of this research show that it is possible to obtain geodetic coordinates with an accuracy at decimeter order, which indicates that the methodology can be used in some engineering applications.","PeriodicalId":55347,"journal":{"name":"Boletim De Ciencias Geodesicas","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67565070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s1982-21702020000400021
Wuyong Tao, Xianghong Hua, Shaoquan Feng
3D similarity transformation is frequently encountered operation in the field of geodetic data processing, and there are many applications that involve large rotation angles. In previous studies, the errors of the coefficient matrix were usually neglected and a least squares algorithm was applied to calculate the transformation parameters. However, the coefficient matrix is composed of the point coordinates in source coordinate system, i.e., the coefficient matrix is also contaminated by errors. Therefore, a total least squares algorithm should be applied. In this paper, a new method is proposed to address the 3D similarity transformation problem with large rotation angles. Firstly, the scale factor and rotation matrix are put together as the parameter matrix to avoid the rank-defect problem. Then, the translation vector is removed and the multivariate model is constructed. Finally, the constraints are introduced according to the properties of the parameter matrix and the constrained multivariate total least squares algorithm is derived to obtain the transformation parameters. The experimental results show that the proposed method has a high computational efficiency.
{"title":"PERFORMING 3D SIMILARITY TRANSFORMATION WITH LARGE ROTATION ANGLES USING CONSTRAINED MULTIVARIATE TOTAL LEAST SQUARES","authors":"Wuyong Tao, Xianghong Hua, Shaoquan Feng","doi":"10.1590/s1982-21702020000400021","DOIUrl":"https://doi.org/10.1590/s1982-21702020000400021","url":null,"abstract":"3D similarity transformation is frequently encountered operation in the field of geodetic data processing, and there are many applications that involve large rotation angles. In previous studies, the errors of the coefficient matrix were usually neglected and a least squares algorithm was applied to calculate the transformation parameters. However, the coefficient matrix is composed of the point coordinates in source coordinate system, i.e., the coefficient matrix is also contaminated by errors. Therefore, a total least squares algorithm should be applied. In this paper, a new method is proposed to address the 3D similarity transformation problem with large rotation angles. Firstly, the scale factor and rotation matrix are put together as the parameter matrix to avoid the rank-defect problem. Then, the translation vector is removed and the multivariate model is constructed. Finally, the constraints are introduced according to the properties of the parameter matrix and the constrained multivariate total least squares algorithm is derived to obtain the transformation parameters. The experimental results show that the proposed method has a high computational efficiency.","PeriodicalId":55347,"journal":{"name":"Boletim De Ciencias Geodesicas","volume":"41 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77499911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s1982-21702020000400019
Bibiana Salvador Cabral da Costa, C. R. Sluter, A. L. Iescheck, E. L. S. Rodrigues
Abstract: In topographic maps, contour lines and elevation points usually represent the variation of height and slope. Contour lines interval defines the level of detail for relief representation. Geomorphological features we can identify on maps are related to contour lines generalization. In this study, we aim to define the necessary level of detail for the cartographic representation of relief features from the sandyzation process. The methodology comprises: defining the relief features associated with sandyzation at the study area by literature review; describing the aspects of data survey using Remotely Piloted Aircraft (RPA) to generate the orthophoto mosaic and the Digital Surface Model (DSM); and using the DSM to extract contour lines at different scales. We defined eight relief features (denudational landform, rill, ravine, micro-residual hill, dune, depositional fan, concentrated flow, and gully) for contour cartographic representation at 1:5,000, 1:1,000, 1:500, 1:200, and 1:100 scales. The results show the scales in which the relief features have their geomorphological characteristics better represented by contours lines. Since there is no reference for suitable scales for the cartographic representation of landforms related to the sandyzation process, this study can contribute to geomorphological researches in areas where this process occurs.
{"title":"LARGE-SCALE CARTOGRAPHIC REPRESENTATION OF RELIEF FEATURES FROM SANDYZATION PROCESS","authors":"Bibiana Salvador Cabral da Costa, C. R. Sluter, A. L. Iescheck, E. L. S. Rodrigues","doi":"10.1590/s1982-21702020000400019","DOIUrl":"https://doi.org/10.1590/s1982-21702020000400019","url":null,"abstract":"Abstract: In topographic maps, contour lines and elevation points usually represent the variation of height and slope. Contour lines interval defines the level of detail for relief representation. Geomorphological features we can identify on maps are related to contour lines generalization. In this study, we aim to define the necessary level of detail for the cartographic representation of relief features from the sandyzation process. The methodology comprises: defining the relief features associated with sandyzation at the study area by literature review; describing the aspects of data survey using Remotely Piloted Aircraft (RPA) to generate the orthophoto mosaic and the Digital Surface Model (DSM); and using the DSM to extract contour lines at different scales. We defined eight relief features (denudational landform, rill, ravine, micro-residual hill, dune, depositional fan, concentrated flow, and gully) for contour cartographic representation at 1:5,000, 1:1,000, 1:500, 1:200, and 1:100 scales. The results show the scales in which the relief features have their geomorphological characteristics better represented by contours lines. Since there is no reference for suitable scales for the cartographic representation of landforms related to the sandyzation process, this study can contribute to geomorphological researches in areas where this process occurs.","PeriodicalId":55347,"journal":{"name":"Boletim De Ciencias Geodesicas","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67564865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s1982-21702020000200011erratum
{"title":"Erratum of the article: MASS APPRAISAL OF APARTMENT THROUGH GEOGRAPHICALLY WEIGHTED REGRESSION","authors":"","doi":"10.1590/s1982-21702020000200011erratum","DOIUrl":"https://doi.org/10.1590/s1982-21702020000200011erratum","url":null,"abstract":"","PeriodicalId":55347,"journal":{"name":"Boletim De Ciencias Geodesicas","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67564908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s1982-21702020000400017
Mariana Pereira do Rego, E. Pugliesi, V. M. Tachibana
Abstract: The main objective of this research is to evaluate the reading time of street names on dynamic egocentrically referenced maps for In-Car Route Guidance and Navigation Systems. Two different road network patterns (grid-like or non-grid-like) were considered and tasks were devised to search for street names in two different route segments (where the driver was, or where the driver would have to manoeuvre). Considering a non-grid-like road network pattern, for the task of searching for the name of a road where the driver would manoeuvre, street names aligned horizontally and next to the route were read significantly faster than street names positioned along the route. Street names positioned obliquely required more reading time than street names aligned horizontally. Dynamic maps egocentrically referenced should present street names horizontally aligned and next to the route for the segment related to where the driver will manoeuvre, for both road network patterns. Also, Street names should be positioned next to the car symbol.
{"title":"THE POSITIONING OF STREET NAMES ON EGOCENTRICALLY REFERENCED MAPS: ASSESSMENT OF READING TIME","authors":"Mariana Pereira do Rego, E. Pugliesi, V. M. Tachibana","doi":"10.1590/s1982-21702020000400017","DOIUrl":"https://doi.org/10.1590/s1982-21702020000400017","url":null,"abstract":"Abstract: The main objective of this research is to evaluate the reading time of street names on dynamic egocentrically referenced maps for In-Car Route Guidance and Navigation Systems. Two different road network patterns (grid-like or non-grid-like) were considered and tasks were devised to search for street names in two different route segments (where the driver was, or where the driver would have to manoeuvre). Considering a non-grid-like road network pattern, for the task of searching for the name of a road where the driver would manoeuvre, street names aligned horizontally and next to the route were read significantly faster than street names positioned along the route. Street names positioned obliquely required more reading time than street names aligned horizontally. Dynamic maps egocentrically referenced should present street names horizontally aligned and next to the route for the segment related to where the driver will manoeuvre, for both road network patterns. Also, Street names should be positioned next to the car symbol.","PeriodicalId":55347,"journal":{"name":"Boletim De Ciencias Geodesicas","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67565173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/s1982-21702020000400018
L. Silva, S. Camboim
Abstract: Cartographic data represents the main and basic component of a Spatial Data Infrastructure. SDI, in turn, has the role of supporting, with strategic information, the most diverse political and economic actions, in the management and planning of public actions. Thus, this work aims, initially, to present an overview of cartography in Brazil through the analysis of the evolution of topographic mapping coverage in the country. For each of the main scales used, a coverage map was created. The analyzes reflect three different periods (until 1997, between 1998 and 2007, after 2008) in order to relate how and to what degree, the creation of Brazilian National SDI (in 2008) had an impact on the mapping production in the country. Given the current panorama, as a final objective, this paper aims at to present proposals to leverage the coverage of this reference data. One of them is the use of new data sources such as Volunteered Geographic Information, especially in areas with outdated mapping or without mapping, as has already been used in some countries. Another proposition is to share the responsibility of mapping through partnerships with other levels of government, which would result the decentralization and the optimization of cartographic production.
{"title":"BRAZILIAN NSDI TEN YEARS LATER: CURRENT OVERVIEW, NEW CHALLENGES AND PROPOSITIONS FOR NATIONAL TOPOGRAPHIC MAPPING","authors":"L. Silva, S. Camboim","doi":"10.1590/s1982-21702020000400018","DOIUrl":"https://doi.org/10.1590/s1982-21702020000400018","url":null,"abstract":"Abstract: Cartographic data represents the main and basic component of a Spatial Data Infrastructure. SDI, in turn, has the role of supporting, with strategic information, the most diverse political and economic actions, in the management and planning of public actions. Thus, this work aims, initially, to present an overview of cartography in Brazil through the analysis of the evolution of topographic mapping coverage in the country. For each of the main scales used, a coverage map was created. The analyzes reflect three different periods (until 1997, between 1998 and 2007, after 2008) in order to relate how and to what degree, the creation of Brazilian National SDI (in 2008) had an impact on the mapping production in the country. Given the current panorama, as a final objective, this paper aims at to present proposals to leverage the coverage of this reference data. One of them is the use of new data sources such as Volunteered Geographic Information, especially in areas with outdated mapping or without mapping, as has already been used in some countries. Another proposition is to share the responsibility of mapping through partnerships with other levels of government, which would result the decentralization and the optimization of cartographic production.","PeriodicalId":55347,"journal":{"name":"Boletim De Ciencias Geodesicas","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67565286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-14DOI: 10.1590/s1982-21702019000300018
E. A. Serrão, Madson T. Silva, F. A. S. Sousa, A. D. Lima, Cleber Assis dos Santos, Lorena Conceição Paiva de Ataíde, V. P. R. D. Silva
Abstract The impacts of anthropogenic degradation are becoming increasingly more evident in the Amazon and are jeopardizing its environmental systems and water resources, particularly in low monitored watersheds. Thus, the use of hydrological models is necessary to gain an understanding of these impacts on Amazonian river systems. The aim of this study was to analyze the simulation of some hydrological processes in the Itacaiunas River watershed and its relation with human-induced impacts in the Southeast region of the Para state using the Soil and Water Assessment Tool (SWAT) model. SWAT modeling requires several databases, such as relief, land use and land occupation, soil type, and climatic and hydrological variables. These data are input parameters for the SWAT model. The results showed that the hydrological variables in the Amazon tend to follow the seasonal precipitation cycle, with the highest values occurring between January and June and lowest between July and November. It was evident that base and lateral flows are responsible for maintaining perennial river flow during the dry season. Regarding anthropogenic actions in the watershed, precipitation, evapotranspiration, and sediment transportation are clearly affected by environmental degradation, as well as by the replacement of forest by grassland and mining activities. The results may assist in public policy including mitigation and adaptation of environmental systems in the region. In addition, they can improve the management of natural resources in the Itacaiunas River watershed.
{"title":"FOUR DECADES OF HYDROLOGICAL PROCESS SIMULATION OF THE ITACAIÚNAS RIVER WATERSHED, SOUTHEAST AMAZON","authors":"E. A. Serrão, Madson T. Silva, F. A. S. Sousa, A. D. Lima, Cleber Assis dos Santos, Lorena Conceição Paiva de Ataíde, V. P. R. D. Silva","doi":"10.1590/s1982-21702019000300018","DOIUrl":"https://doi.org/10.1590/s1982-21702019000300018","url":null,"abstract":"Abstract The impacts of anthropogenic degradation are becoming increasingly more evident in the Amazon and are jeopardizing its environmental systems and water resources, particularly in low monitored watersheds. Thus, the use of hydrological models is necessary to gain an understanding of these impacts on Amazonian river systems. The aim of this study was to analyze the simulation of some hydrological processes in the Itacaiunas River watershed and its relation with human-induced impacts in the Southeast region of the Para state using the Soil and Water Assessment Tool (SWAT) model. SWAT modeling requires several databases, such as relief, land use and land occupation, soil type, and climatic and hydrological variables. These data are input parameters for the SWAT model. The results showed that the hydrological variables in the Amazon tend to follow the seasonal precipitation cycle, with the highest values occurring between January and June and lowest between July and November. It was evident that base and lateral flows are responsible for maintaining perennial river flow during the dry season. Regarding anthropogenic actions in the watershed, precipitation, evapotranspiration, and sediment transportation are clearly affected by environmental degradation, as well as by the replacement of forest by grassland and mining activities. The results may assist in public policy including mitigation and adaptation of environmental systems in the region. In addition, they can improve the management of natural resources in the Itacaiunas River watershed.","PeriodicalId":55347,"journal":{"name":"Boletim De Ciencias Geodesicas","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2019-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47195446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}