Halit Apaydin

M5 model tree application in daily river flow forecasting in Sohu Stream, Turkey

This study investigate the potential of M5 model tree in predicting daily stream flows in Sohu river located within the municipal borders of Ankara, Turkey. The results of the M5 model tree was compared with support vector machines. Both modelling approaches were used to forecast up to 7-day ahead stream flow. A comparison of correlation coefficient and root mean square value indicates that M5 model tree approach works equally well to the SVM for same day discharge prediction. The M5 model tree also works well up to 7-day ahead discharge forecasting in comparison of SVM with this data set. An advantage of using M5 model tree approach is the availability of simple linear models to predict the discharge as well use of less computational time.

Estimating Pan Evaporation from Limited Meteorological Observations from Turkey

ABSTRACT Pan evaporation measurements are widely used to estimate evapotranspiration and free water evaporation. Pan evaporation measurements are critical to many applications including irrigation system design, irrigation scheduling, and hydrologic modeling. In many locations, reliable climate measurements consist of daily minimum screen temperature, daily maximum, rainfall, and windspeed. In many situations, it is advantageous to calculate rather than measure pan evaporation. Many formulas have been developed which predict pan evaporation as a function of limited meteorological observations. One of them, a simplified version of Penmans evaporation formula, requires only temperature, wind and dewpoint data in addition to latitude and elevation. This paper evaluates the Penpan Equation for the case of a pan and tests its universality. Estimates differ from measured values by about 0.65 mm/day at 19 locations in Turkey.