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It is possible to do real Hydrology without a GIS. But having one is better.

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3 introduction gis

  1. 1. An Introduction to GIS Land Information Systems Fahlstrom - Map of the Worls Silvia Franceschi Friday, September 10, 2010
  2. 2. An Introduction to GIS - Land Information Systems Objectives: 2 Silvia Franceschi Friday, September 10, 2010
  3. 3. An Introduction to GIS - Land Information Systems Land Information Systems (LIS) Geographic Information Systems (GIS)‫‏‬ 3 Silvia Franceschi Friday, September 10, 2010
  4. 4. An Introduction to GIS - Land Information Systems Definition: ! There is not a precise definition for the meaning of GIS ! The definition depends on the “cultural context” 4 Silvia Franceschi Friday, September 10, 2010
  5. 5. An Introduction to GIS - Land Information Systems Definition: ! There is not a precise definition for the meaning of GIS ! The definition depends on the “cultural context” 4 Silvia Franceschi Friday, September 10, 2010
  6. 6. An Introduction to GIS - Land Information Systems Definition: ! There is not a precise definition for the meaning of GIS ! The definition depends on the “cultural context” ! The proliferation of specialised slang ! Difficulties in understanding between professionals 4 Silvia Franceschi Friday, September 10, 2010
  7. 7. An Introduction to GIS - Land Information Systems Information System: Set of tools, procedures, and people that have the task to organise, select, archive, and communicate the data regarding the activities of an organisation (public or private). Its objective is to make available to the decision makers all the information necessary to make the best possible choices. “Set of tools to acquire, extract, process, archive, and REPRESENT spatial data from the real world” (Burrough 1986) “Set of procedures, founded on the use of information technology, used to archive and process georeferenced data” (Aronoff 1989) 5 Silvia Franceschi Friday, September 10, 2010
  8. 8. An Introduction to GIS - Land Information Systems History Originally developed in Canada, GIS soon spread all over the world. They are mainly used by public bodies to manage land data. The use of GIS has grown greatly in the last ten years as an essential tool for urban planning, and the management and planning of environmental resources. Their diffusion is due, mainly, to the great capacity to save, recover, analyse, model, and map large areas by means of very large amounts of spatial data. GIS are now widely used in the environmental field and in research because of the possibility to access different data correlated by their position in space. 6 Silvia Franceschi Friday, September 10, 2010
  9. 9. An Introduction to GIS - Land Information Systems Information System: GIS are information systems dedicated to the study and management of geographic data. By means of these tools it is possible to: - collect; - model; - manipulate; - analyse; and - present geographically referenced data or, to put it better, GEOREFERENCED data. GIS allows the superposition of various levels of information regarding an area. It is therefore possible to obtain a better understanding of the processes that affect the area and the factors that characterise it. 7 Silvia Franceschi Friday, September 10, 2010
  10. 10. An Introduction to GIS - Land Information Systems Information System: Immagine non modificabile. 8 Silvia Franceschi Friday, September 10, 2010
  11. 11. An Introduction to GIS - Land Information Systems GIS – What is it? ! Geographic Information ! Information relating to the position of an object on the surface of the Earth ! Knowledge of “what is in a certain place at a certain time (we must not forget the time factor)” ! Geographic Information Technologies ! Technologies for working with these data ! Global Positioning Systems (GPS)‫‏‬ ! Remote Sensing (RM)‫‏‬ ! Geographic Information Systems (GIS)‫‏‬ 9 Silvia Franceschi Friday, September 10, 2010
  12. 12. An Introduction to GIS - Land Information Systems GIS – Geographic Information System 1. Complete tool suitable for land representation and the processing of CAD DATABASE data associated with georeferenced objects. GIS 2. To each object (points, lines, areas) spatial coordinates are assigned that Image are congruent with the cartographic Processing base reference. 3. GIS integrates the characteristics of various types of software. To use a GIS is not limited to just using a software tool, but rather it means adopting a working method. 10 Silvia Franceschi Friday, September 10, 2010
  13. 13. An Introduction to GIS - Land Information Systems What a Geographic Information System (GIS) is not. The most common error when referring to GIS is to confuse the Geographic Information System with one or more of its component technologies. ! - cartographic base ! - GIS is not a digital cartography ! - the cartographic base is simply one of the starting points upon which a GIS is developed ! - GIS is not a more or less developed software package ! - it is a system that requires the existence of a well- defined project by the end user ! - it is a MODEL REPRESENTATION OF THE REAL WORLD and, therefore, a working method 11 Silvia Franceschi Friday, September 10, 2010
  14. 14. An Introduction to GIS - Land Information Systems Application Fields - Agriculture (land use)‫‏‬ - Real Estate Management - Economics (market analyses)‫‏‬ - Earth Observation - Defence (logistics, planning)‫‏‬ - Telecommunications - Ecology and landscape conservation - Administrative Data - Utility networks (water, gas, power)‫‏‬ Management - Civil Protection - Infrastructure Management - Natural Resource Management - Preparation of Maps and - Land Registry Databases - Forestry - Mining and Extraction - Public Health (epidemiology)‫‏‬ - Surveying and Topography - Education - Transportation and Logistics - Geography - Urban Planning - Oceanography - Research 12 Silvia Franceschi ... Friday, September 10, 2010
  15. 15. An Introduction to GIS - Land Information Systems How does a GIS work? Immagine non modificabile. 13 Silvia Franceschi Friday, September 10, 2010
  16. 16. An Introduction to GIS - Land Information Systems Using Data GIS allows for the organised archiving of data used in analytical and management activities. The geographic data can be correlated with each other, organised into structures and according to needs. Generally, the data that can be imported are: - graphic elements (points, lines, areas)‫‏‬ - images - attribute data associated with the preceding elements 14 Silvia Franceschi Friday, September 10, 2010
  17. 17. An Introduction to GIS - Land Information Systems What questions can be answered? ! Position: What is there in ...? ! Conditions: Where is ...? ! Trends: What has changed ...? ! Spatial distribution: What spatial distribution is there? ! Modelling: What happens if ...? 15 Silvia Franceschi Friday, September 10, 2010
  18. 18. An Introduction to GIS - Land Information Systems Examples ! Position: What type of soil can be found at these coordinates? Or near this type of structure? ! Conditions: Identify the areas which fall within the temporal buffer zone (60 days) for water wells ! Trends: What type of vegetation has undergone changes in comparison with the 1950 map? ! Spatial distribution: Is there a correlation between vulnerable areas and nitrate pollution? ! Modelling: What happens if the public wells of Milan are polluted? 16 Silvia Franceschi Friday, September 10, 2010
  19. 19. An Introduction to GIS - Land Information Systems Main Functions • Entering and verifying data • Data transformations: set of operations used to correct and homogenise the data set (coordinate transformation, editing,...) • Data storage: in an appropriate DBMS • Analysis: application of conceptual models that reproduce the physical phenomenon being studied, with new data being created as a consequence • Output of results: in various forms (digital, cartographic...)‫‏‬ • Models of geographic data: the data of a geographic data base are made up of three components: • Spatial aspect: geometry/topology • Quality aspect • Semantic aspect: alphanumerical, numerical, and statistical attributes 17 Silvia Franceschi Friday, September 10, 2010
  20. 20. An Introduction to GIS - Land Information Systems Cartography A MAP can be simply defined as a graphic representation of the real world. Maps are only a representation, it is not possible to include in a map all the complexity of reality. Maps can be used to visualise cultural and physical aspects of an environment. Topographic maps are those that represent general information, such as the disposition of roads, land use, altitude, rivers, water bodies... However, there are also maps that represent non-geographical elements, such as the maps of meteorological evolution, temperature, pressure... The use of these maps is decidedly more specialistic than that of topographical maps. 18 Silvia Franceschi Friday, September 10, 2010
  21. 21. An Introduction to GIS - Land Information Systems Cartography ! Set of: ! coordinates associated to elements (points, lines, polygons)‫‏‬ ! relationships between elements ! attributes of the elements It can be seen as the reverse of traditional paper mapping: ! traditional mapping: drawing coordinates ! digital mapping: coordinates drawing The content and uses of digital mapping are greater than those of traditional mapping (in fact, the latter can be derived from the former). 19 Silvia Franceschi Friday, September 10, 2010
  22. 22. An Introduction to GIS - Land Information Systems Scale The concept of SCALE may seem redundant in digital mapping because it is possible to view and print the data at an magnification, given that the coordinates are absolute. However, the scale depends on the precision of the coordinates. Nominal scale: scale at which the map print has the same metric requirements of the traditional map (precision, graphical error). 20 Silvia Franceschi Friday, September 10, 2010
  23. 23. An Introduction to GIS - Land Information Systems Spatial Relations between Elements There are three types of relations between elements: : ! spatial ! topological ! proximity Directional relations: they depend on the orientation of the map ! opposite north ! on the other side south ! above east ! below west and combinations of orientations. 21 Silvia Franceschi Friday, September 10, 2010
  24. 24. An Introduction to GIS - Land Information Systems Topological Relations EQUIVALENCE PARTIAL EQUIVALENCE CONTAINMENT ADJACENCY SEPARATENESS 22 Silvia Franceschi Friday, September 10, 2010
  25. 25. An Introduction to GIS - Land Information Systems Proximity Relations These indicate, QUALITATIVELY and QUANTITATIVELY the distance between objects: ! qualitative: ! near ! far ! in the vicinity of .. ! quantitative: d=1532 m 23 Silvia Franceschi Friday, September 10, 2010
  26. 26. An Introduction to GIS - Land Information Systems Information Layers In digital cartography the information layers can be separated (very often they need to be). HYDROGRAPHIC NETWORK SETTLEMENTS PRIMARY ROAD NETWORK 24 Silvia Franceschi Friday, September 10, 2010
  27. 27. An Introduction to GIS - Land Information Systems Data: Elements and Fields Spatial data is traditionally divided into two classes: RASTER and VECTOR FIELDS or RASTERS: objects defined almost everywhere within the domain of interest, very often continuous. For example, temperature, pressure, altitude. They are represented in discrete form with regular matrices of attributes (matrix models or georeferenced rasters), triangular irregular networks (the TIN model), or with contour lines. ELEMENTS or VECTORS: discrete and discontinuous objects that are precisely defined. For example, buildings, administrative areas, road networks. They are represented with vectorial models, that may also be topological, with associated tables of attributes. 25 Silvia Franceschi Friday, September 10, 2010
  28. 28. An Introduction to GIS - Land Information Systems Fields Altitude (DTM: Digital Terrain Model)‫‏‬ 26 Silvia Franceschi Friday, September 10, 2010
  29. 29. An Introduction to GIS - Land Information Systems Raster DTM 27 Silvia Franceschi Friday, September 10, 2010
  30. 30. An Introduction to GIS - Land Information Systems DTM/DEM "Digital Elevation Model" (DEM): it represents the elevations of a particular surface. When using a DEM, the reference surface must always be stated. "Digital Terrain Model" (DTM): it represents the elevations of the surface of the Earth, that is to say the terrain. A DTM is a specific case of a DEM where the surface represented is that of the Earth. “Digital Surface Model” (DSM): it represents the elevation of the surface of the Earth, including those elements that are above the surface. 28 Silvia Franceschi Friday, September 10, 2010
  31. 31. An Introduction to GIS - Land Information Systems DTM/DEM The DTM and DEM describe a continuous surface by means of a finite number of three-dimensional points (x,y,z values) in space (x,y,z). The xyz triplets are usually distributed irregularly because they have been obtained by different measuring methods. These irregular points are generally put into a regular grid (usually square with the same amplitude in the x-direction as in the y-direction) by means of various interpolating methods (e.g. kriging, spline, least squares,...). Each triplet (x,y,z) of the DTM/DEM represents, therefore, an area, that is to say, a square of the grid. The squares are called CELLS or PIXELS (= picture elements). 29 Silvia Franceschi Friday, September 10, 2010
  32. 32. An Introduction to GIS - Land Information Systems DTM 30 Silvia Franceschi Friday, September 10, 2010
  33. 33. An Introduction to GIS - Land Information Systems TIN - (Triangular Irregular Network)‫‏‬ 31 Silvia Franceschi Friday, September 10, 2010
  34. 34. An Introduction to GIS - Land Information Systems Contour Lines 32 Silvia Franceschi Friday, September 10, 2010
  35. 35. An Introduction to GIS - Land Information Systems Contour Lines 33 Silvia Franceschi Friday, September 10, 2010
  36. 36. An Introduction to GIS - Land Information Systems Elements: Points, Line, and Areas 34 Silvia Franceschi Friday, September 10, 2010
  37. 37. An Introduction to GIS - Land Information Systems Elements ! The elements are made up of: ! geometric primitives: ! point ! curve ! surface ! topological primitives: ! node ! edge ! face 35 Silvia Franceschi Friday, September 10, 2010
  38. 38. An Introduction to GIS - Land Information Systems Rasterisation of the Elements 36 Silvia Franceschi Friday, September 10, 2010
  39. 39. An Introduction to GIS - Land Information Systems Rasterisation of the Elements 37 Silvia Franceschi Friday, September 10, 2010
  40. 40. An Introduction to GIS - Land Information Systems Comparison: Raster - Vector ! Vector ! Raster ! advantages advantages ! ! memory use ! algebra on maps ! explicit topology ! operations are simple ! “resolution”, precision and intuitive for the of the coordinates user ! disadvantages ! some operations are disadvantages ! taxing ! memory operations ! overlay is complicated ! implicit topology 38 Silvia Franceschi Friday, September 10, 2010
  41. 41. An Introduction to GIS - Land Information Systems Raster - Vector 39 Silvia Franceschi Friday, September 10, 2010
  42. 42. An Introduction to GIS - Land Information Systems Raster - Vector 40 Silvia Franceschi Friday, September 10, 2010
  43. 43. An Introduction to GIS - Land Information Systems Raster - Vector 41 Silvia Franceschi Friday, September 10, 2010
  44. 44. An Introduction to GIS - Land Information Systems Topology Topological relations are relations between objects that are independent of the orientation of the map, and invariant to elastic or continuous deformations (e.g. change of reference system and/or coordinate system). These relations are used to express congruity constraints Immagine non modificabile. between objects. 42 Silvia Franceschi Friday, September 10, 2010
  45. 45. An Introduction to GIS - Land Information Systems Raster Geometric Primitives These are based on frames with which space is divided into regular shapes and sizes. Each element is defined by its row and column numbers (2D) and layer number (3D). The position of the origin of the reference system must be defined. 43 2 Silvia Franceschi Friday, September 10, 2010
  46. 46. An Introduction to GIS - Land Information Systems Raster Geometric Primitives - 2D GRID: regular distribution of points defined by the nodes of the grid, derivable from a 2D structure. They are completely defined by row and column numbers. PIXEL: two-dimensional geometric primitive, corresponding to the basic element of a 2D structure. 44 Silvia Franceschi Friday, September 10, 2010
  47. 47. An Introduction to GIS - Land Information Systems Raster Geometric Primitives - 2D GRID: regular distribution of points defined by the nodes of the grid, derivable from a 2D structure. They are completely defined by row and column numbers. PIXEL: two-dimensional geometric primitive, corresponding to the basic element of a 2D structure. 44 Silvia Franceschi Friday, September 10, 2010
  48. 48. An Introduction to GIS - Land Information Systems Topological Geometric Primitives NODE: 0-dimensional primitive. It can be connected (by an edge) or isolated. EDGE: 1-dimensional topological primitive. It represents an orientated connection between two nodes (that may coincide). FACE: 2-dimensional geometric primitive, described by an external ring (a closed set of edges that do not cross) and either none or many internal rings. 45 Silvia Franceschi Friday, September 10, 2010
  49. 49. An Introduction to GIS - Land Information Systems Vector File Formats The most common vector file format is undoubtedly the shapefile format: .shp. A shapefile is made up of a family of files which, specifically, includes: ! .shp contains the information related to the form of the features ! .shx contains an index of the position of the features to speed up the queries made ! .dbf contains the attributes related to the features ! .prj contains the information related to the coordinate system and the projection of the data ! .shp.xml contains the metadata linked to the features Other formats supported by the vast majority of GIS are: tab, dxf, dwg, E00, ..., ascii. 46 Silvia Franceschi Friday, September 10, 2010
  50. 50. An Introduction to GIS - Land Information Systems Raster File Formats The most common are: • TIFF • GIF • JPEG • ASCII The raster files of images that can be viewed with a GIS need to contain information relating to the coordinate system and the projection. Files such as TIFF files, therefore, need to be georeferenced. That is to say, they must be GEO-TIFF files. The information relating to the projection can be included within the TIFF file itself or it can be written to a separate file, usually with extension TFW (or JGW). ASCII files contain all information relating to the region and the localisation of the data. 47 Silvia Franceschi Friday, September 10, 2010
  51. 51. An Introduction to GIS - Land Information Systems Overview of Open Source Desktop GIS •The most widespread GIS in the field of open source GIS are: -GGRASS: the oldest of the open source GIS. Originally developed by the United States Department of Defence, it is very powerful in raster analysis (www.grass.itc.it) -JUMP: viewer which offers the possibility of vectorial data analysis (http://openjump.org) -GVSIG: viewer which offers the possibility of vectorial data analysis. There is also an integration of raster components but not sufficient for raster analysis (www.gvsig.gva.es) -QGIS: considered the simple graphic interface for GRASS (www.qgis.org) -JGRASS: GIS dedicated to environmental analysis, it allows the viewing and analysis of raster and vector data (www.jgrass.org) -uDig: vectorial data and image viewer (http://udig.refractions.net) 48 Silvia Franceschi Friday, September 10, 2010
  52. 52. An Introduction to GIS - Land Information Systems Overview of Commercial Desktop GIS I most widespread GIS in the field of commercial GIS are: • ESRI: ArcGIS, Arcview, Arcreader... probably the the biggest family of GIS software in the commercial field (www.esri.com) • ERDAS-IMAGINE: satellite image management (www.geosystems.de) • ERMAPPER: high-resolution image management ( orthorectification, mosaic, reprojection, colour balance and compression) • MAPINFO: very easy to use; best described as a viewer that manages vectorial data well (www.mapinfo.com) • AutoCAD Map 2004: advanced management of geographic data along with image management (www.autodesk.com) 49 Silvia Franceschi Friday, September 10, 2010
  53. 53. An Introduction to GIS - Land Information Systems GIS Support Databases The database is an essential component of the GIS in that it contains all the information that will be viewed and analysed, both with desktop GIS and WebGIS. In the field of proprietary databases, the most widespread are: • ORACLE: with a spatial extension to support geometries (Oracle- Spatial) • ArcSDE: spatial database by ESRI • Access: this is not a spatial database but a mechanism can be constructed to link information to geometric features. The most widespread open source databases are: • Postgres: the most popular, with spatial extension PostGIS • HSQLDB: this is not a spatial database, it is only a relational database ... 50 Silvia Franceschi Friday, September 10, 2010
  54. 54. An Introduction to GIS - Land Information Systems Open Source WebGIS The two open source development environments for geospatial data currently used are: ! GEOSERVER ! MAPSERVER Graphic interfaces for these products are available for the production of WebGIS such as those that are often found on the websites of public bodies and research centres. Some tools of this type are: ! Ka-Map ! Py-WPS ! ... 51 Silvia Franceschi Friday, September 10, 2010
  55. 55. An Introduction to GIS - Land Information Systems Open Source WebGIS 52 Silvia Franceschi Friday, September 10, 2010
  56. 56. An Introduction to GIS - Land Information Systems Italian Digital Cartography Immagine non modificabile 53 Silvia Franceschi Friday, September 10, 2010
  57. 57. An Introduction to GIS - Land Information Systems GIS Characteristics With respect to the purely geometric representation of objects, a GIS also needs to store and manage the information about the mutual spatial relationships between the various elements. That is, it must structure the data and define the topology. As well as geometric and topological data, the GIS must also allow for the insertion of descriptive data relative to individual real objects, that is to say the ATTRIBUTES. The structure that is capable of saving the spatial and geometric relations and attributes is referred to as a relational structure. 54 Silvia Franceschi Friday, September 10, 2010
  58. 58. An Introduction to GIS - Land Information Systems GIS Characteristics In a GIS, the coordinates of an object are neither stored with respect to an arbitrary reference system nor with respect to the coordinate system of the device being used. They are stored according to the reference system in which the object is really found and with their real dimensions, not to scale. The scale of representation becomes solely a parameter used to define the level of accuracy and the resolution of the graphical information. Depending on the scale, smaller elements may not be visualised and one sees only areas of terrain characterised by the same quantity. GIS allows us to manage the data like 3-dimensional objects in a real 3- dimensional system. No longer do we need to simply attribute a height to an object. 55 Silvia Franceschi Friday, September 10, 2010
  59. 59. An Introduction to GIS - Land Information Systems GIS Characteristics Starting from a TIN, a DTM or a DEM it is possible to: ! interpolate contour lines 56 Silvia Franceschi Friday, September 10, 2010
  60. 60. An Introduction to GIS - Land Information Systems GIS Characteristics 57 Silvia Franceschi Friday, September 10, 2010
  61. 61. An Introduction to GIS - Land Information Systems GIS Characteristics Starting from a TIN, a DTM or a DEM it is possible to: ! interpolate contour lines ! carry out a visibility analysis 58 Silvia Franceschi Friday, September 10, 2010
  62. 62. An Introduction to GIS - Land Information Systems GIS Characteristics 59 Silvia Franceschi Friday, September 10, 2010
  63. 63. An Introduction to GIS - Land Information Systems GIS Characteristics Starting from a TIN, a DTM or a DEM it is possible to: ! interpolate contour lines ! carry out a visibility analysis ! generate longitudinal profiles 60 Silvia Franceschi Friday, September 10, 2010
  64. 64. An Introduction to GIS - Land Information Systems A partire da un TIN, un DTM o un DEM è possibile: GIS Characteristics ! interpolare curve di livello ! effettuare un'analisi di visibilità ! generare profili longitudinali 61 Silvia Franceschi Friday, September 10, 2010
  65. 65. An Introduction to GIS - Land Information Systems GIS Characteristics Starting from a TIN, a DTM or a DEM it is possible to: ! interpolate contour lines ! carry out a visibility analysis ! generate longitudinal profiles ! carry out slope analysis, exposition analysis... 62 Silvia Franceschi Friday, September 10, 2010
  66. 66. An Introduction to GIS - Land Information Systems GIS Characteristics 63 Silvia Franceschi Friday, September 10, 2010
  67. 67. An Introduction to GIS - Land Information Systems GIS Characteristics Starting from a TIN, a DTM or a DEM it is possible to: ! interpolate contour lines ! carry out a visibility analysis ! generate longitudinal profiles ! carry out slope analysis, exposition analysis... ! calculate real distance, taking account of the vertical coordinate 64 Silvia Franceschi Friday, September 10, 2010
  68. 68. An Introduction to GIS - Land Information Systems GIS Characteristics 65 Silvia Franceschi Friday, September 10, 2010
  69. 69. An Introduction to GIS - Land Information Systems GIS Characteristics Starting from a TIN, a DTM or a DEM it is possible to: ! interpolate contour lines ! carry out a visibility analysis ! generate longitudinal profiles ! carry out slope analysis, exposition analysis... ! calculate real distance, taking account of the vertical coordinate ! query a list of attributes and extract the required values 66 Silvia Franceschi Friday, September 10, 2010
  70. 70. An Introduction to GIS - Land Information Systems GIS Characteristics 67 Silvia Franceschi Friday, September 10, 2010
  71. 71. An Introduction to GIS - Land Information Systems GIS Characteristics Starting from a TIN, a DTM or a DEM it is possible to: ! interpolate contour lines ! carry out a visibility analysis ! generate longitudinal profiles ! carry out slope analysis, exposition analysis... ! calculate real distance, taking account of the vertical coordinate ! query a list of attributes and extract the required values ! extract the morphological characteristics of the terrain 68 Silvia Franceschi Friday, September 10, 2010
  72. 72. An Introduction to GIS - Land Information Systems GIS Characteristics 69 Silvia Franceschi Friday, September 10, 2010
  73. 73. An Introduction to GIS - Land Information Systems GIS Characteristics Starting from a TIN, a DTM or a DEM it is possible to: ! interpolate contour lines ! carry out a visibility analysis ! generate longitudinal profiles ! carry out slope analysis, exposition analysis... ! calculate real distance, taking account of the vertical coordinate ! query a list of attributes and extract the required values ! extract the morphological characteristics of the terrain ! process quantities relative to the hydrographic network 70 Silvia Franceschi Friday, September 10, 2010
  74. 74. An Introduction to GIS - Land Information Systems GIS Characteristics 71 Silvia Franceschi Friday, September 10, 2010
  75. 75. An Introduction to GIS - Land Information Systems GIS Characteristics Starting from a TIN, a DTM or a DEM it is possible to: ! interpolate contour lines ! carry out a visibility analysis ! generate longitudinal profiles ! carry out slope analysis, exposition analysis... ! calculate real distance, taking account of the vertical coordinate ! query a list of attributes and extract the required values ! extract the morphological characteristics of the terrain ! process quantities relative to the hydrographic network ! carry out stability analysis of the catchment ! carry out hydrological analysis at event scale ! ... 72 Silvia Franceschi Friday, September 10, 2010
  76. 76. An Introduction to GIS - Land Information Systems JGRASS The Research Centre for the development of algorithms implemented in JGrass is the Department of Civil and Environmental Engineering of the University of Trento (Italy) and CUDAM (University Centre for the Defence of Mountain Environments), also at the University of Trento. The Development Centre is HydroloGIS of Bolzano (Italy), although there are other developers at CUDAM in Trento. The JGrass starting point is GRASS GIS, which currently represents the most important Open Source project in the GIS field. GRASS is slowly evolving towards an attractive solution for the commercial and productive sectors. The biggest obstacle to the commercial blooming of GRASS is without doubt its versatility problem. Many professionals use Windows and Mac-OS as the preferred operating systems, and many businesses do not provide the possibility of using Linux (which is the operating system upon which GRASS development is based). 73 Silvia Franceschi Friday, September 10, 2010
  77. 77. An Introduction to GIS - Land Information Systems JGRASS JGrass, developed to simplify the use of GRASS on different operating systems, has set itself the following objectives: •versatility - the possibility to run GRASS on Windows, Unix/Linux and Mac-OS indifferently (write once, run everywhere) •the possibility for anyone, by means of the framework that has been created, to develop with ease additional modules, particular functions, and application oriented interfaces by means of XML scripting •scripting - the possibility to use a Java-based scripting language in order to automatise certain processes (programmer and scientific - work oriented) •simplicity of use - menu bars, tool bars and icons aimed at simplifying the interface (end-user friendly) 74 Silvia Franceschi Friday, September 10, 2010
  78. 78. An Introduction to GIS - Land Information Systems JGRASS Over the last number of years various attempts have been made to combine the strengths of Java and GRASS. The first of these was the wrapping of the GRASS libraries in Java by Alexandre Sorokine. Shortly thereafter, at the Centre for Environmental and Nuclear Sciences of the University of the West Indies (Jamaica), John Preston began to develop a Java/Swing application for the visualisation of geochemical maps. At the beginning of 2003 Dr Rigon, of the Department of Civil and Environmental Engineering and CUDAM of the University of Trento, decided to support the Jamaican project in a concrete way by supplying funds and a developer, and coordinating with the research group at ITC, which includes Markus Neteler. In this way the development of JGrass began. 75 Silvia Franceschi Friday, September 10, 2010
  79. 79. An Introduction to GIS - Land Information Systems JGRASS At the moment JGrass is an application that can be run locally, although the future implementation of remote running is planned. It is a Java/ RCP application based on an MDI (multiple document interface) and provides standardised ways of interaction between the interface and the GRASS kernel. Although we are trying to keep JGrass, as much as possible, in "pure Java", some parts are still written in the native language of GRASS by means of Sun's API JNI technology. 76 Silvia Franceschi Friday, September 10, 2010
  80. 80. An Introduction to GIS - Land Information Systems JGRASS JGrass is a free and open source GIS that can be freely downloaded from the website: www.jgrass.org All the instructions for use are found on the same webpage, along with documents of the available commands. 77 Silvia Franceschi Friday, September 10, 2010
  81. 81. An Introduction to GIS - Land Information Systems Thank you for your attention. G. Ulrici - 78 Silvia Franceschi Friday, September 10, 2010

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