Pluvial flooding (PF), triggered by intense short-duration rainfall events, poses a growing challenge in urban areas due to climate change and rapid urbanization. To mitigate the risk, it is imperative to identify flood-prone areas and implement mitigation strategies collaboratively with the public. This study aims to create a GIS-MCDA model of PF susceptibility zones based on topographical, environmental, and hydrological criteria and investigate the public perception of risk in Gospić. The survey included 5% of the city population (N=64), and data were obtained via face-to-face interviews. Five factors were examined: (F1) risk awareness, (F2) anthropogenic and (F3) natural causes of PF, (F4) potential consequences, and (F5) preparedness. All factors have moderate mean values, i.e., awareness, causes of PF, expectations of consequences, and preparedness is moderate. The reliability of questionnaire is very high (> 0.71). The PF susceptibility zones were derived with an accuracy of 76%. The most susceptible zone covers 10% of the city, including agricultural land, forests, meadows, and residential properties. Of all respondents, 36% live in the most flood-prone area. In conclusion, mitigation measures for decision-makers were proposed. Results from this research can be a starting point for further research in Croatia and guidelines for decision-makers in implementing a risk mitigation strategy.

This work examines drought and wet events based on Standardized Precipitation-Evapotranspiration Index (SPEI) over Kenya from 1981 to 2016. Spatiotemporal analysis of dry and wet events is conducted for 3 and 12-month SPEI. The drought incidences were observed during the period 1984, 1987, 2000, 2006, 2009, 2015, and 2016 for SPEI-3 whilst the SPEI-12 demonstrated the manifestation of drought during the year 2000 and 2006. SPEI clearly shows that the wettest period, 1997 and 1998 that coincide with the El Nino event in both time steps. SPEI -3 shows a reduction in moderate drought events while severe and extreme cases were on increase towards the end of the twentieth century. Conversely, SPEI-12 depicts an overall increase in severe drought occurrence over the study location with observed intensity of -1.54 and cumulative frequency of 64 months during the study period. The trend of wet events is upwards in the western and central highlands while the rest of the regions show increase in dry events during the study period. Moreover, moderate dry/wet events predominate whilst extreme events occur least frequent across all grid cells. It is apparent that the study area experiences mild extreme dry events in both categories although moderately severe dry events dominate most parts of the study area. High intensity and frequency of drought is noted in SPEI-3 while least occurrences of extreme events are recorded in SPEI-12. Although drought event prevails across the study area, there is evidence of extreme flood conditions over the recent decades. These findings form a good basis for next step of research that will look at projection of droughts over the study area based on regional climate models.

The report [1] shows that in many European cities the sewer system is older than 40 years, potentially reducing their ability to cope with more intense pluvial flooding [2] addition to climate change, urbanization is an important factor increasing the flooding risk, as it increases of impervious surfaces. Flash floods are particularly troublesome, causing not only the overloading of drainage systems [3], but also urban transport disruption, affecting human health, and contributing to pollution due to untreated sewage discharges [4]. Pluvial floods in urban areas are caused by short-duration precipitation, high intensity and on small scale. Such rainfall is difficult to predict and does not always apply to catchment areas. In Poland, heavy rainfall lasts relatively short, from a few minutes to a few, at most, several hours [5]. The method of the Analytic Hierarchy Process (AHP) was used to rank the importance of criteria characterizing exposure in urban areas. The ranking is based on expert judgements. The article focuses on exposure which is one of the components of risk. Geographical Information System (GIS) is integrated with Multicriteria Decision Analysis (MCDA) to evaluate exposure of urban area on pluvial floods.

The impact of pluvial flooding will hamper the economic process in South Jakarta. The best solution for pluvial flooding is to use mobile pumps and its equipment. There has been no previous research regarding the use of mobile pumps in pluvial floods, either in South Jakarta or elsewhere. The aim of this research is to optimize mobile pumps and their equipment for pluvial floods in South Jakarta through hydrological calculations, hydraulic engineering and risk analysis. The method used is to carry out hydrological analysis compared with the hydraulic capabilities of existing channels, correlation of rainfall intensity and flood depth and analysis of hazard risks through the impact of flood depth and duration of flooding. A depth of flood 75 cm has a 20-50% chance of occurring. The hourly rain distribution pattern in South Jakarta was in the first 2 hours with a percentage weight of 56.6% in the 1st hour and 43.4% in the 2nd hour. BMKG Radar Image as the main choice for rain detection. Optimization of mobile pumps and their equipment can be done through a hierarchy of sufficient and insufficient channel capacity, flood frequency, high impact and time of flooding, mobile pump entry access, mobile pump SOP and equipment. There are 8 locations that require mobile pumps in South Jakarta and it is possible to install these mobile pumps. Seven of them require weather prediction tools and SCADA and 3 of them require mobile pump SOP. From the simulation results using the outlet condition that is out of the system, it is found that the configuration heading to the upstream of the flooded channel cross-section shows the most optimal results. This is because the mobile pump is able to trim the flood hydrograph from the beginning, namely in the flooded upstream. In addition, the criteria for using the type of mobile pump used with weather prediction is a mobile pump with a minimum capacity of 0.5 m3/s. The use of mobile pumps is a solution to reduce the risk of pluvial flooding in South Jakarta and other urban areas.