The specific geographic location of Sarajevo, which is located in a valley surrounded by mountains, provides the opportunity to analyze the relation between the concentration of PM10 and meteorological parameters with and without temperature inversion. The main aim of this paper was to develop forecasting models of the hourly average of PM10 values in the Sarajevo urban area based on meteorological parameters measured in Sarajevo and on the Bjelasnica mountain with and without temperature inversion by using principal component regression (PCR). Also, this research explored and analyzed the differences in the values of the meteorological parameters and PM10 in Sarajevo with and without temperature inversion, and the difference in temperatures between Sarajevo and Bjelasnica with temperature inversion using statistical hypothesis testing with a total of 240 hypothesis tests performed. The measurements of meteorological parameters were taken from 2020 to 2022 for both Sarajevo (630 m) and the Bjelasnica mountain (2067 m), which allowed for the identification of time periods with and without temperature inversion, while measurements of PM10 were taken only in Sarajevo. Data were collected during the heating season (November, December, January, February and March). Since analyses have shown that only January and November had time periods with and without temperature inversion during each hour of the day, a total of seven cases were identified: two cases with and five cases without temperature inversion. For each case, three PCR models were developed using all principal components, backward elimination and eigenvalue principal component elimination criteria (λ<1). A total of 21 models were developed. The performance of the models were evaluated based on the coefficient of determination R2 and the standard error SE. The backward elimination models were shown to have high performances with the highest value of R2= 97.19 and the lowest value of SE=1.32. The study showed that some principal components with eigenvalues λ<1 were significantly related to the independent variable PM10 and thus were retained in the PCR models. In the study, it was shown that backward elimination PCR was an adequate tool to develop PM10 forecasting models with high performances and that it could be useful for authorities for early warnings or other action to protect citizens from very harmful pollution. Hypothesis tests showed different relations of meteorological parameters and PM10 with and without temperature inversion.

: In this paper, wind energy potential in Sarajevo area, Bosnia and Herzegovina, was analyzed statistically. The analysis of wind energy potential was performed based on measured wind data in a one-year period from 1 January to 31 December 2019. Measured data were obtained on the basis of a meteorological station installed on the roof of the building of the Faculty of Mechanical Engineering in Sarajevo at 30 m height. Measured wind characteristics were statistically analyzed using the Weibull and Rayleigh distribution functions. The Weibull parameters were obtained using two methods, the energy pattern factor method and the maximum likelihood method, and both methods were used to find the Weibull parameters and the wind power density. The results of this investigation showed that the analyzed place falls under Class 1 of the international system of wind classification as the mean annual wind velocity recorded in the analyzed area was 1.215 m/s and the corresponding annual mean power density was estimated to be 6.7 W/m 2 at 30 m height. The results show that the available wind energy potential to generate electricity in Sarajevo is low and wind power cannot be used to meet the energy needs in that region.

The occurrence of extreme precipitation, floods, and dry periods, according to all forecasts, will probably become more frequent both in Europe and in Bosnia and Herzegovina. For this reason, it is necessary to consider climate change when designing infrastructure facilities. Following this, this paper aims to assess the flow rate data based on the daily measured values obtained at the Reljevo hydrological station on the Bosna River. The analyses are conducted for two periods (1961-1990 and 2000-2010) to obtain the temporal distribution of relevant flow rate data. For observed periods, analysed data are compared