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Understanding of GIS Geographic Information System (GIS) or Geographic Information System (GIS) is an information system designed to work with spatially referenced data or berkoordinat geography or in other words, a GIS is a database system with specific capabilities for handling spatial referenced data ( spatial) working in conjunction with a set of operations (Barus and Wiradisastra, 2000). Meanwhile, according to Anon (2001) Geography Information System is a system that can integrate information between graphical data (spatial) with text data (attributes) that are connected in geogrfis objects on earth (GIS). In addition, GIS can also combine data, organize data and perform data analysis which ultimately will result in output that can be used as a reference in decision-making on issues related to geography. The Geographic Information System is divided into two groups: a manual system (analog), and automated systems (digital-based computers). The most fundamental difference lies in the way of management. Information system manuals usually incorporate some data like maps, transparencies to overlap stacking (overlay), aerial photographs, statistical reports and field survey reports. All data is compiled and analyzed manually with a tool without a computer. While automated Geographic Information System has been using the computer as a data processing system through a process of digitization. Source of digital data can be either satellite imagery or digital aerial photographs and digitized aerial photographs. Other data can be digitized base map (Nurshanti, 1995). Understanding GIS / SIG today is more often applied to the spatial or geographic information technologies oriented to the use of computer technology. In conjunction in with computer technology, Arronoff (1989) in Anon (2003) defines GIS as a computer-based system that has the ability to handle data that is referenced geographic data entry, data management (storage and recall), manipulating and analyzing data, and output as the final result (output). While Burrough, 1986 defines Geographic Information System (GIS) as a computer-based systems are used to input, store, manage, analyze and re-enable the data that have a spatial reference for various purposes related to mapping and planning. The main components of Geographic Information System can be divided into four main components: hardware (digitizer, scanner, Procesing Central Unit (CPU), hard-disk, etc.), software (ArcView, Idrisi, ARC / INFO, ILWIS, MapInfo, etc.), organization (management) and user (the user). The correct combination of the four main components of this will determine the success of a Geographic Information System development project. the GIS applications can be used for various purposes for which data is processed to have geographic references, meaning the data is composed of a phenomenon or object that can be presented in physical form and has a spatial location (Indrawati, 2002). PURPOSE GIS The main objective of the utilization of Geographic Information System is to facilitate getting information that has been processed and stored as an attribute of a location or object. The main characteristic of data that can be used in Geographic Information Systems is the data that has been tied to location and is the basic data that has not been specified (Dulbahri, 1993). The data are processed in a GIS is essentially composed of spatial data and attribute data in digital form, thus the analysis can be used is the analysis of spatial and attribute analysis. Spatial data is data relating to the spatial location of the general shape of the map. While the data attribute is a data table that serves to explain the existence of various objects as spatial data. 3 WAYS OF SPATIAL DATA Presenters The presentation of spatial data has three basic ways in the form of dots, lines form and shape of the area (polygon). Point is a single appearance of a pair of coordinates x, y which shows the location of an object of height, location of the city, sampling locations and others. The line is a set of points which form an elongated appearance such as rivers, roads, etc. kontus. While the appearance of the area is bounded by a line which forms a homogeneous space, for example: regional boundaries, limits the use of land, islands and so forth. Spatial data structure that is divided into two models of raster data and vector data models. Raster data is the data stored in the form of a rectangular box (grid) / cell, forming a regular space. Vector data is the data recorded in a form that displays the coordinates of points, placing and storing spatial data using points, lines or areas (polygons) (Barus and Wiradisastra, 2000). STATEMENT LUKMAN Lukman (1993) states that the geographic information system provides spatial information and its attributes which consists of several main components, namely: 1. Input data is the data entry process on a computer from maps (topographic maps and thematic maps), statistical data, data analysis results of remote sensing data from remote sensing digital image processing, and others. Spatial data and attribute either in the form of analog or digital data is converted into the format requested by the software, forming a database (database). According to Anon (2003) database is organizing the data that is not redundant in the computer so it can do the development, renewal, calling, and can be used jointly by the user. 2. Data storage and recall (data storage and retrieval) is a data storage on the computer and call back quickly (look at the screen and can be displayed / printed on paper). 3. Data manipulation and analysis activities that can be done is a variety of command between the two themes such as overlaying a map, create a buffer zone some distance from an area or point, and so on. Anon (2003) says that the manipulation and analysis of data is a major feature of the SIG. GIS capabilities in a joint analysis of spatial data and attribute data will yield information useful for various applications 4. Reporting data is able to present the basic data, the data processing results from the model data into the form of maps or tabular data. According to Barus and wiradisastra (2000) form of the product of a GIS can be varied both in terms of quality, accuracy and ease of the wearer. These results can be made in the form of maps, tables figures: the text on paper or other media (hard copy), or in the print software (such as electronic files). The STATEMENT Anon According to Anon (2003) there are several reasons why it is necessary to use GIS, including: 1. GIS uses spatial and attribute data in an integrated 2. GIS can digunakansebagai exciting interactive tool in the effort to increase understanding of the concept of location, space, population, geography and the elements that exist on the surface of the earth. 3. GIS can be split between the form of presentations and databases 4. GIS has the ability to decipher the elements that exist on the surface of the earth into several layers or spatial data coverage 5. SIG has a very good Traffic in visualizing spatial data following attributes 6. All GIS operations can be performed interactively 7. GIS easily menghsilkan thematic maps 8. all GIS operations can be in the Customize by using the commands in the script Bahaa. 9. Peragkat GIS software provides the facility to communicate with other software 10. GIS greatly helped the work that is closely related to the field of spatial and geoinformatika. STATEMENT Barus and WIRADISASTRA Barus and Wiradisastra (2000) also revealed that the SIG is a reliable tool for handling spatial data, where the GIS data is maintained in digital form so that this data is more dense than in the form of printed maps, charts or in other conventional forms that will eventually speed up the work and alleviate the cost required. Primary means for spatial data handling is a GIS. GIS is designed to receive large amounts of spatial data from various sources and mengintergrasikannya become an informed, one type of data is remote sensing data. Remote sensing has the ability to generate spatial data structure with a geometry close to the real situation quickly and in large quantities. Barus and Wiradisastra (2000) says that the SIG will give added value to the remote sensing capability to produce large spatial data in which the utilization of remote sensing data depends on how the handling and processing of data which will convert it into useful information.