Mapping of Stream Flow Trends in Porsuk Basin Using GIS Environment

In this study, trends of minimum, average and maximum flows were investigated in Porsuk basin, which is a sub-basin of Sakarya basin and then changes in flows were mapped using Geographical Information Systems (GIS). In the study, in 10 flow gauging stations across the Porsuk basin, monthly average, maximum and minimum flow data is used covering the period 1961-2013 (53 years). When analyzing the distribution of observed trends in the basin, a trend has been observed in most of the river flows. A decreasing trend has been observed overall in the basin. Trends are generally decreasing over time except for a few stations. As a result, increasing trends are observed in the west part of the basin;while in the east part of the basin decreasing trends are observed. When average and maximum monthly flows are investigated, decreasing trends are observed in the stations except DSI-12182. Trend analysis of 10 flow gauging stations across the Porsuk basin is investigated by Mann-Kendall method. Trend distribution was made according to flow trends of basin by transferring Z values to GIS.

Mapping of Precipitation, Temperature and Evaporation Distributions in the Porsuk Basin Using Distant Forecasting Methods

Geographical data are of great importance in meteorology and climate science. These data can create the areal distribution models analyzed by spatial interpolation methods. The values of the areas without measurement data are estimated with these distribution models. In this study, distribution of meteorological parameters such as precipitation, temperature and evaporation in Porsuk basin, which is determined as research area, was investigated by Inverse Distance Weighting (IDW) and Ordinary Kriging methods. Actual meteorological data analyzed of the basin do not show a normal distribution statistically. Therefore, the data were firstly subjected to normalization and then analyzed according to the IDW and Ordinary Kriging methods to create distribution maps of precipitation, temperature and evaporation data. Quadratic mean error values were compared to investigate the reliability of analyzes. In this study, the analysis results of precipitation, temperature and evaporation data have been calculated by two different methods. Ordinary Kriging method has been determined as the method making the most accurate estimation.

Formation of Eskisehir Province Flood Maps with Using of Geographical Information Systems

In this study, it is aimed to develop the flood risk analysis of Porsuk River, which is responsible for naming of the Porsuk Basin sub basin of Sakarya Basin, by utilizing the methods of Remote Sensing (RS) and Geographical Information Systems (GIS). In addition, flood elevation effects of Porsuk River in Eskişehir city and the regions around were investigated. Necessary data for study were obtained from Eskişehir 3. Regional Directorate of State Hydraulic Works archives. For analyses, the cross section of Porsuk River was defined in the Hydrologic Engineering Centers River Analysis System (HEC-RAS) software. Subsequently, recurring periods of 50, 100 and 1000 years discharge of Porsuk River which is calculated as 51.83 m3/s, 60.15 m3/s and 86.66 m3/s respectively were inputted in the software to obtain analysis results. Obtained results from the present study and topographic data were compared and interpreted. As a result, elevation of flood and its risks for urban regions were studied and presented.