The study of hydrological risk assessment is performed with the goal to reduce impacts of droughts and floods. Drought is the most complex but least understood of all natural hazards. It is broadly defined as "severe water shortage". Floods cause huge but mainly material damages. Mentioned natural hazards cause loss of life, human and animal suffering and damage to economy and environment. The present study area is prone to extreme climate events such as drought and flood. The objective of this study was to investigate precipitation trends in the chosen climatic stations in Libya and Slovakia. Annual and monthly precipitation trends were detected by the Mann-Kendall statistical test. Significant negative trends of annual precipitation were found in four out of seventeen analyzed rainfall gauging stations in Libya. Significant positive trends of annual precipitation were found in six out of twenty analyzed rainfall gauging stations in Slovakia. November and August were observed to have decreasing trends in Libya and March in Slovakia. All other months displayed increasing trends in precipitation. The results show a trend towards drier conditions in Libya and an increase of moisture in Slovakia.

Precipitation and its development over time is an important indicator of climate change. Research on long-term precipitation totals is absent in the Slovak Republic. This paper deals with the statistical analysis of daily precipitation from 48 precipitation stations in Slovakia. The paper evaluates the spatial distribution of precipitation in Slovakia and also presents analyses of stationarity and trends using the Mann-Kendall test. Emphasis is placed especially on the evaluation of the trends in total annual precipitation, maximum daily precipitation and also the number of days without precipitation in the year. By evaluating the trends in these three indicators, it is possible to assess the impact of potential change in the temporal and spatial distribution of precipitation on hydrological drought and floods. The results show that there are currently no significant changes in precipitation in Slovakia. The problem of floods and hydrological drought seems to be more complex and is mainly due to surface water drainage from the landscape and the change in its use in connection with the increase in the average annual temperature.

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Trend analysis is one of the most commonly used tools for detecting changes in climatic and hydrologic time series. Attempts are devoted to the study of seasonal climatology in Syria, including information on the level of rainfall at various climatic stations in Syria for the period 1991-2009. Wet (from October to May) and dry (June to September) seasonal precipitation are obtained from surface observations. There are numbers of statistical tests that exist to assess the significance of trends in time series. However, the existence of positive autocorrelation in the data increases the probability of detecting trends when actually none exist, and vice versa. Most of the recent studies about climate change suggest that the behavior of some of the climatological variables has already changed and will continue to change towards increasing or decreasing magnitudes and frequencies, depending on the type of variable. Increased rainfall and following floods are expected in some regions while other regions will experience smaller rainfall and longer droughts, meaning water scarcity.

Environmental hazards (natural and man-made) have always constituted problem in many developing and developed countries. Many applications proved that these problems could be solved through planning studies and detailed information about these prone areas. Determining time and location and size of the problem are important for decision makers for planning and management activities. It is important to know the risk represented by those hazards and take actions to protect against them. Multicriteria analysis methods - Analytic hierarchy process, Pairwise comparison, Ranking method are used to analyse which is the most dangerous hazard facing Libya country. The multicriteria analysis ends with a more or less stable ranking of the given alternatives and hence a recommendation as to which alternative(s) problems should be preferred. Regarding our problem of environmental risk assessment, the result will be a ranking or categorisation of hazards with regard to their risk level.