The optimum use of the spatial data produced by the institutions using geographical information systems

Today, information sharing that increases and develops with the contribution of the internet requires the construction of information system substructure not only for the employees of institutions but also for the users these institutions serve. The institutions which make maps and which have maps made also tend towards Geographical Information Systems (GIS) to be able to keep their archives up-to-date, to be able to reach existing data quickly and to be able to follow an efficient and contemporary working policy. Within this context, in order to be able to continue their services fast and effectively and to be able to keep up with the requirements of the age such as city information systems, institutions, especially local administrations, have their present up-to-date maps done. The production of town maps which are needed by different institutions and users is a time consuming and costly process that requires intense working in the field and office. Thus, it is very important to know the maps produced so that they can be reached when necessary because reproducing an already produced map by another institution won't be an economical approach. In line with these subjects, the objective of this study is to develop a Geographical Information System based approach to prevent duplication in the production of existing maps, to eliminate waste of resources, to enable more efficient use of existing maps and to ease reaching new information by questioning with the existing data. A map data bank was formed to unite existing maps and information produced with this approach under the same umbrella to enable the institutions making maps and those who have maps made to benefit from technological resources. Practices which form the basis of local administration services such as network plans of infrastructure projects including city development plans, drinking water, sewage system, rain water, electricity, natural gas, etc.; design, practice and management of transportation systems; numbering and city information systems are made on town maps. Construction plans and thus town maps of a specific area are also needed in order to be able to grant license to buildings such as residential buildings and places of business which remain outside the construction plans as a result of the developments in the city and in order to be able to bring service to these areas. Within this context, the management of maps with Geographical Information System has been established for reaching the information that is needed in a quick way, for exchanging up-to-date information in different user levels and for preventing the repeat of the production of existing data and as a conclusion for creating time and budget. The first section of the study includes the objectives and content of the study. In the second section of the study, map was defined in general and kinds of maps, which were classified in terms of their subjects and areas of usage, were explained. The concept of scale of map, which is important for classifying maps and also for showing details, was defined. Map projections, which are the projections of three dimensional physical earth on a two dimensional geometrical surface, and the reference surfaces used in this projection were explained. The coordinate systems which do not define the earth were also described. In the third section of the study, the definition of town maps, which is the main subject of this study, and which show every kind of detail in the area studied such as triangulation, RS points, benchmarks, buildings, number of floors of buildings, roads, pavements, streets, height curves of places outside roads and curves, lamp posts, block and parcel boundaries and numbers, forests, cemeteries, official institutions, rivers, canals, etc, produced three dimensionally by state institutions and organizations or natural and legal persons in a specific reference system with a scale of 1/5000 or greater according to the regulations of Large Scale Map and Map Information Production Guides (LSMMIPG) was made. Town map production through ground surveying method and photogrammetric mapping method was described. In addition, the production process of town maps produced by İlbank A.Ş., the bank of provinces, was described with its stages. Town map production practices are practices that require precise measurement and calculation. With the spatial data that occur as a result of the production of town maps and by predicating upon the elevation and coordinate values of these data, a great number of significant engineering projects are designed such as dams, bridges, roads, construction plans, infrastructure projects and they are applied in the field by taking these data as the basis. Due to their critical significance in engineering projects, town maps are checked regularly and precisely by control organizations during their production processes. During the process of taking approval for the measurements of town maps, a great number of documents are asked by the institutions such as the control reports of every stage of the town map, calibration documents of measurement devices, coordinate measurement scales, polygon sheets, triangulation sheets and leveling preliminary survey sheets, GPS layout plans, GPS balancing measurements and results, triangulation measurement tables and sheets, control points and referencing sketches, detail and tachometric survey outlines. In the production of maps with photogrammetric mapping method, land works are not exactly eliminated. It is inevitable to refer to land at the beginning and end of the practices and it is also inevitable to work in the land. However, detail measurements, which make up a significant part of land works, are carried to the office. In terms of mapping, the primary thought that has led to the development of photogrammetric mapping is to turn expensive land works into cheaper office works as much as possible. Today, land works have increasingly become less and less frequent. In the fourth section of the study, Geographical Information System was defined and information was given about its components. The tasks of collecting data, managing data, processing data, presenting data, questioning data spatially and analyzing data were explained. Web Geographical Information System, which is called the internet Geographical Information System that enables the transfer and share of spatial information and map services to other users through the internet, was explained. In the fifth section of the study, the material and method used in the study were explained. Information was given about the ArcGIS program, which was used throughout the study. In the sixth section of the study, the practice was described with its steps. Town maps with a scale of 1/5000 which were produced under the control of İlbank A.Ş., the bank of provinces, Samsun regional directorate were used in the study. The preparation of the data to be used in the program in line with the purposes, the creation of the dataset, the creation of feature classes in the coordinate system which has been determined, the association of graphic information with textual information (table documents) in a suitable way by integrating the graphic information to the system and the storage of these in the correct format were explained respectively. The study questioned whether any 1/5000 scale map can be produced in terms of year and city without using the map sheets and volumes in the map archive, obtained the coordinates of polygon and triangulation points, found the polygons in 1/5000 scale sheet and displayed point benchmark sketch. As a conclusion, a method was formed which enabled more functional use of town maps and data. In the seventh section of the study, the results and recommendations of the study were presented and a general evaluation was made. Map images of towns were shown and the field information of these was presented in tables. As a conclusion, the objective of this study was to increase awareness in institutions which make maps and which have maps made and to help these institutions to make use of the advantages of the developing technology and to reach town maps more easily. Another objective of the study was to make the study a guide for future studies to be conducted and the whole map sector. Our country has very big land. Instead of producing again and again maps of areas which have been mapped before and the map information of which has been given before, making maps of places which have not been mapped before will both save resources and also cause an opportunity for new investors to come to places which have been mapped. When this study is presented web-based, it will also be possible for users in other institutions to access to this study.