{"id":4974,"date":"2022-01-24T17:58:28","date_gmt":"2022-01-24T15:58:28","guid":{"rendered":"https:\/\/triplex-confinium.eu\/?p=4974"},"modified":"2022-01-24T17:58:28","modified_gmt":"2022-01-24T15:58:28","slug":"working-with-g-i-s","status":"publish","type":"post","link":"https:\/\/triplex-confinium.eu\/sr\/2022\/01\/24\/working-with-g-i-s\/","title":{"rendered":"WORKING WITH G.I.S."},"content":{"rendered":"
\n\t
\n\t\t
\n\t\t\t\n\t\t<\/div>\n\t<\/div>\n<\/div><\/div><\/div><\/div>
\n\t
\n\t\t
\n\t\t\t

Understanding water as a tool forming the heritage<\/b><\/p>\n\n\t\t<\/div>\n\t<\/div>\n<\/div><\/div><\/div><\/div>

\n\t
\n\t\t
\n\t\t\t
\n

The Introduction to GIS lecture and the the two support workshops (working with GIS, and Understanding Water as a tool for forming heritage), offered Triplex Confinium students with theoretical knowledge as well as practical competence in mapping the competition site. The tested tools and mapping methodologies will set the basis for our enhanced GIS course.<\/span><\/i><\/p>\n<\/blockquote>\n\n\t\t<\/div>\n\t<\/div>\n<\/div><\/div><\/div><\/div>

<\/div>
<\/div><\/div><\/div>\n\t
\n\t\t
\n\t\t\t\n\t\t<\/div>\n\t<\/div>\r\n

LECTURE: Understanding GIS<\/strong><\/p>\r\n

Geographical information system (GIS) is a type of information system consisting of computer hardware and software, (geo)database and users, which is used to enter, store, manipulate, analyze and retrieve geographic (geospatial) data in order to solve various problems. Today GIS helps many users in various fields: urban planning, environmental management, transport, demography, public administration, business, etc.<\/i>The key components of GIS include software and hardware, geographic data (geodatabase) that is analyzed with the help of particular methods and users.\u00a0<\/span><\/p>\r\n

The computer system consists of hardware and software components, which are used to perform the functions of collecting, processing, analyzing, modeling and retrieving information. Sources of geographical (geospatial) data include digitalized maps, aerial photographs and satellite images, statistical tables and other documents that can be converted into a compute system readable information. Geographic data are organized in a special way in geographic databases (GIS databases). They include both geometric (X and Y coordinates) and attributive (or thematic) data about real-world objects. With the help of geometric data, real-world objects are presented in GIS in two types of formats: vector or raster. Vector data consists of three elements – a point, a line and a polygon. Raster data consists of pixels that represent cells in the raster grid .<\/span><\/p>\r\n

Figure 1 Vector and raster data in GIS (www.eo4geo.eu)<\/span><\/i><\/p>\r\n

\"\"<\/a><\/span><\/p>\r\n

Geometric data characterize the location (coordinates), topology (spatial relationships), size, shape, and orientation of objects in space. Attributive or thematic data describe the properties (qualities) of objects and phenomena. The attribute data for the objects are stored in tabular form in the so-called “Attribute tables”. The geometric and attributive data for each object are interconnected in the geographic database. This means that geographic objects can be identified and localized using their attributes, and vice versa (fig.2).<\/span><\/p>\r\n

Figure 2 Geographic and attribute data in a GIS (De Mers, 2009)<\/span><\/i><\/p>\r\n

\"\"<\/a><\/p>\r\n

The role of users is to select, update and analyze the information in GIS that interests them to solve a particular problem. The term “user” refers both to the individual specialist working in the field of GIS and to organizations (government, non-governmental, educational and corporate) whose mission is in some way related to GIS.\u00a0<\/span><\/p>\r\n

In order to visualize the real world GIS specialists use digital models. Digital maps and attributive information (databases) are used to represent the real world in GIS. The organizational structure of those maps are based on layered organization of GIS data. Each model of reality is a separate layer, representing individual objects such as streets, plots, infrastructure etc. Each layer contains geometric (coordinate) data and related attributes, organized in a special way in an attribute table (fig. 3).<\/span><\/p>\r\n

Figure 3 GIS layers (Parida et al., 2019)<\/span><\/i><\/p>\r\n

\"\"<\/a><\/p>\r\n

For a given area, multiple layers can be combined and the connections between objects in the individual layers can be revealed. In reality, even in a small area, there are an infinite number of objects and the description of all of them will require an infinitely large database and an infinite number of layers. Since we do not have the necessary resources (time, computer memory, etc.), we create a digital model only for those objects and phenomena that interest us (the so-called “Target GIS”). This model does not cover all the diversity in the real world. Therefore, when creating the digital model we use classification and abstraction. In classification, we group similar objects and phenomena into separate classes \/ layers. In abstraction we make a selection of objects and phenomena and their characteristics in accordance with the goal and choose the model by which to present them in GIS.\u00a0<\/span><\/p>\r\n

The representation of a territory as a combination of layers is an abstraction (e.g. Jimbolia region as a “sandwich” of layers “relief”, “water bodies”, “soils”, etc.). Separate layers can be created for “streets”, “buildings”, “museums”, “addresses” which together (in combination) represent a model of reality.<\/span><\/p>\r\n

There are relationships between the attributes in these layers – the addresses are related to the streets and the buildings to the addresses. The buildings have owners, built-up and developed area, floors, type of construction and other attributes; the streets are one-way or two-way, have restrictions on speed, type of pavement and other attributes.<\/span><\/p>\r\n

When we obtain the computer system and our geodata we can proceed to perform a spatial analysis in order to solve the real-world existing problem. For that we can use different questions:\u00a0<\/span><\/p>\r\n