110 INTRODUCTION For the water management process, the data on river’s fow rates it of utmost importance. Therefore, the river fow rate determination is a focus of every hydrological research. Runof plots are very important means to monitor run- of and soil loss (Baoyan et al., 2017). Unfortu- nately, many catchments are ungauged, and thus there are limitations for food calculation using rainfall-runof models (Nam & Shin, 2018). As stated, hydrological modeling is instrumental for both scientifc application and for providing pub- lic services (Kolbjorn & Alfredsen, 2020). When there is a lack of data on the river fow rates and many parameters of catchment proper- ties are missing, then another aproach must be considered. The measurement model states in the form of equations, the relationship between the measurements and the true value of interest (McMillan et al., 2018; Nearing et al., 2016). Due to the lack of fow rate measurements, the relationship between rainfall and fow can help solve this defciency. The fow forecasting as in- vestigated in this paper, can rely solely on using the available rainfall data. The Suhareka muncipality is on the sothern part of Kosovo and is characterised with the con- tinental climate with the Mediterenean impact. The Suhareka river, fowing through this region is a small river but with higher fow oscilations through out the year, meaning that the Q max /Q min fow relation is quite high. The Suhareka River is also known as a dry river, but since 2015 it has been fooding the downstream areas about 3 times and damaging the agriculture and industrial activity in its vicinity. Therefore, the integrated food management is a priority in this area and it requries the knowledge of the probabilistic fow duration curves. On the basis of the hydrologic data availibility, there are some methods that can be used in this regard. The rain intensity (i) ore rain height (H) dependence on duration time (tk) and return period (P), can be determined in Flow Rate Determination as a Function of Rainfall for the Ungauged Suhareka River Laura Kusari 1 , Lavdim Osmanaj 1* , Hana Shehu 1 , Samir Bungu 1 1 Faculty of Civil Engineering, University of Pristina, Kosovo * Corresponding author’s e-mail: lavdim.osmanaj@uni-pr.edu ABSTRACT For ungauged rivers, when there are no hydrological measurements and there is a lack of data on perennial fow rates, the latter one to be determined based on other hydrological data. The river Suhareka catchment represents a similar case. Since there is no data on Suhareka’s fow rates, the authors of this study aimed for the fow rate de- termination based on rainfall measurements. From the available data on annual precipitation (monthly sums) pro- vided by the Kosovo Hydrometeorological Institute for the Suhareka hydrometric station, the observed monthly rainfall data for 30 years were analysed. Those gaps were initially flled by connecting the hydrometric station in Suhareka with those of Prishtina, Prizren and Ferizaj, and as a result a fairly good ft was ensured. Moreover, the intensity-duration-frequency curves were formed using the expression of Sokolovsky, as a mathematical model of the dependence I (T, P). For a transformation of rainfall into fow, the American method SCS was used. As a result, the equation for the Suhareka River basin was derived, which enabled the determination of maximum infows, for diferent return periods. The results obtained through this paper, indicates that even for ungauged river basins the peak fows can be determined from available rainfall data. Keywords: catchment area, regression coefcient, CN parameter, rainfall intensity, fow curves, rainfall foods. Journal of Ecological Engineering Received: 2021.12.30 Accepted: 2022.02.14 Published: 2022.03.01 Journal of Ecological Engineering 2022, 23(4), 110–121 htps://doi.org/10.12911/22998993/146355 ISSN 2299–8993, License CC-BY 4.0