Comparative Calculation of 3-Dimensional Surface Area and Water Flow Direction from Digital Elevation Models: A Case Study For The Agricultural Land in Eskisehir-Cifteler Irrigation

Abstract

The significance of agricultural production and, consequently, numerous agriculture-related parameters are becoming the primary focus of the digitalized world, and with the 2019 pandemic, the significance of food was once again highlighted. In order to ensure the correct and necessary use of water in agriculture, valid surface area values by calculating the irrigated parcel areas in 3-dimensions (3D) are required. The main purpose is to more accurately calculate the amount of water used in irrigation areas on a parcel-by-parcel basis using 3D area values, thereby preventing the plant from receiving insufficient or excessive water. In this way, it is hoped that this will increase efficiency and help prevent losses in agricultural production by ensuring that irrigation calculations are based on accurate area estimates. This thesis compared the calculated area values derived from 3D data to the areas listed on the title deeds for the study area located in the Eskisehir-Cifteler region. To achieve the stated objective, DEMs were obtained from institutions and publicly accessible data sources. In addition, information regarding the DTM's points was obtained from the General Directorate of Land Registry and Cadaster (GDLRC). Utilizing elevation models and parcel data, the 3D measurements of the parcels were obtained. Upon conducting an analysis, it is seen that there is a difference of 235 hectares between the total surface area (GDLRC) and the total title deed area for the selected test site. The area under investigation is a farming community that covers an estimated total of 10.677,05 hectares. Compared to the total area, the difference might be underestimated; however, considering the country level, it was found to be at a level that could potentially cause substantial agricultural discrepancies.