RECLAMATION STRUCTURES IN THE LOCATION AND GEOREFIN DATA COMPARATIVE ANALYSIS
Keywords:drenažo sistemos, melioracija, MelGIS, georeferenciniai duomenų rinkiniai
The object of the land amelioration and the amelioration structure database is the Lithuanian national and private reclaimed land and structures that are located on site or are assigned to the land. The data include the information about ameliorated land and related amelioration structures. Digital graphic accounting material for the land amelioration and its structures is prepared in accordance with the specification of the land amelioration geographical information system (MelGIS) for M 1: 2000 projects scanned and linked to LKS-94. GIS systems are used in the thesis. Due to the data inaccuracies, municipal amelioration specialists encounter issues, managing amelioration structures and systems under the law of state trust, as well as farmers, who operate amelioration structures and systems, project designers who plan amelioration structure repair and reconstruction projects, and amelioration construction specialists searching for the exact locations of underground amelioration systems.
Data collected by control photographs of ditches before renovation is analysed in the thesis. The coordinates of the ditch furrows, the depth, permeability, direction, location and diameter of the drainage collectors, leading to the ditch were determined by geodetic measurements. The quality of the data was assessed using accurate measurement data and compared with data sets generated from scanned design material. Deviations of design objects from actual data. Errors were identified and other discrepancies were assessed. Objects transferred from scanned reconstruction design projects were found containing most location inaccuracies. The most accurate data were derived from ortophotographic material of ditches and other objects.