Statistical analyses and hydrometeorological parameters of long-year water levels and volumes: example of lake Egirdir

Global warming, climate change, rapid urbanization and industrialization, population growth, unplanned and random water use considerably affect the lake water level (LWL) and lake water volume (LWV), which is very important since the lakes are clean water sources. For this study, Lake Egirdir, with a tectonic structure and basin area of approximately 3445.6 km within the borders of Isparta province, was chosen. In the study, long-year lake water level measurement station values of Lake Egirdir and long-year temperature, precipitation, relative humidity, wind speed values of the Egirdir meteorology station were used as variables. To develop equations between the Egirdir lake water level, volume and hydro-meteorological variables, the best fitted sub-equation models analysis, analysis of variance and multiple regression analyses (MRA) were performed. Their statistical relevance was examined with 5% significance level F, correlation (r) and probability (p) tests. Analysis of variance of each MRA equation developed to determine LWL and LWV estimation values was evaluated. In line with these values, it has been determined that the MLRA equation is more suitable than the Multiple Nonlinear Regression Analysis (MNRA) equation in estimating LWL, and the MNRA equation is much more suitable than the Multiple Linear Regression Analysis (MLRA) equation in estimating LWV. With the help of the equations developed for LWL and LWV estimations, it has been concluded that the Egirdir lake basin water management planning and project design studies within the hydrological cycle can have an idea beforehand. As a result, we think that it is very important to carry out the necessary planning and management studies in advance by revealing the current status of water resources in the future by carrying out these and similar studies.