Bridge piers on large rivers are often protected from scouring using launchable stone, such as a riprap sloping structure. While such scour countermeasures are effective for pier protection, they significantly alter flow conditions in the bridge opening by overtopping flow and flow contraction, deflecting the formation of the scour hole downstream and exposing the downstream riverbed to additional scour. This paper provides a comprehensive and relevant review of bridge scour estimation methods for piers with a riprap sloping structure installed as a scour countermeasure. Research on empirical methods for bridge scour estimation is reviewed and analyzed with formulae used for comparable structures—complex pier formulae and formulae for river training structures. A summary of relevant formulae applicable to piers with installed scour countermeasures is provided, as well as a discussion on the possible future research directions that could contribute to the field.

Flood risk management (FRM) aims to integrate necessary technical measures with environmental and societal approaches. Focusing on the process and governance of how to plan, implement, and maintain solutions therefore becomes essential. Among the different stakeholders, landowners are a key group to be considered. This contribution elaborates on the interconnections between land policy, FRM and private land ownership. It is based on the European COST Action network LAND4FLOOD, which brings together academics and stakeholders from various disciplines and more than 35 countries. We argue for a less project oriented and more process oriented approach, a focus on land management and more emphasis on small‐scale measures. This represents a break with some of the recent working paradigms of FRM.

Nowadays, great emphasis is placed on the relationship between forest and water because forests are considered as substantial sources of many water ecosystem services. The aim of this paper is to analyze the stakeholder opinions towards the relationship between forests and water and the potential development of water-related payments for ecosystem services (PES) schemes. The study is developed in the context of COST Action CA15206–PESFOR-W (Forests for Water) aimed at synthesizing current knowledge about the PES schemes across Europe. The stakeholder opinions were mapped out using a structured questionnaire consisting of 20 questions divided into four thematic sections. The data were collected through an online survey. The results showed opinions of 142 stakeholders from 23 countries, mainly from Eastern Europe and the Mediterranean Basin. In order to analyze the collected data, the stakeholders were grouped in buyers, sellers, intermediaries, and knowledge providers. The survey results indicated that the most important category of water ecosystem services according to our sample of stakeholders is regulating services followed by provisioning services. Further findings pointed out the highest importance that shared values and direct changes in land management can have when designing water-related PES schemes. The role of public authorities and collective collaboration of different stakeholders, with emphasis on local and expert knowledge, are also identified as of crucial importance. The results show that stakeholder opinions can serve as a starting point when designing PES schemes.

This paper examines the level of payment for ecosystem services (PES) concept implementation in the financing of water-related forest ecosystem services (ES) in the Republic of Croatia, the Federation of Bosnia and Herzegovina (FB&H), the Republic of Slovenia, and the Republic of Serbia. The focus is on water-related forest ES recognised by the millennium ecosystem assessment (MEA). For the purpose of this paper, the term pure PES describes schemes that comply to all five conditions set by Wunder definition and term PES like for those schemes that miss some of those conditions. In the first step, the most important legislative documents related to forests, water, and environmental protection were selected. The second consists of a content analysis; focusing on the definition of ES; the definition of fees or payments; the establishment of ‘forest funds’, ‘water funds’, or ‘environmental funds’; and the way these funds were spent. Here we looked at the flow of funding into the forestry sector recognising forest management as the main water-related forest ES provider. Research revealed existence of well-established payments schemes in forestry in Croatia for almost 30 years and in FB&H for some 20 years which were assessed as closest to pure PES. In Serbia and Slovenia, there were no PES or PES like schemes in the forestry sector. In the water sector the well-established PES like payments schemes existing in all four countries. The environmental protection sector, however, rely more on the tax like rather than on the PES like schemes. Legislation in general recognised the link between forests and water, but this was much more evident in the forestry than in the water or environment sector. The role of the state is strongly pronounced in all countries studied, and was the main driving force behind all payments. However, this position of the state represents also the main obstacle for the development of pure PES schemes, together with underdeveloped private forestry and complex socio-economic conditions. Nevertheless, there is room for further development of pure PES and PES like schemes based on EU or global experiences.

Morphodynamic changes in the riverbed may be accelerated by the climate change-induced effects, mostly through the increase of the frequency of extreme climatic events such as floods. This can lead to scouring of the riverbed around the bridge substructure and consequently reduces its overall stability. In order to better understand hydromorphological processes at the local scale, the influence of floods on bridge scour requires a detailed analysis of several interacting flood hydrograph characteristics. This paper presents a multivariate analysis of the annual maximum (AM) flood discharge data at four gauging stations on the Drava and Sava Rivers in Croatia (Europe). As part of the hydrograph analysis, multiple baseflow separation methods were tested. Flood volumes and durations were derived after extracting the baseflow from measured discharge data. Suitable marginal distribution functions were fitted to the peak discharge (Q), flood volume (V) and duration (D) data. Bivariate copula analyses were conducted for the next pairs: peak discharge and volume (Q–V), hydrograph volume and duration (V–D) and peak discharge and hydrograph duration (Q–D). The results of the bivariate copula analyses were used to derive joint return periods for different flood variable combinations, which may serve as a preliminary analysis for the pilot bridges of the R3PEAT project where the aim is to investigate the influences on the riverbed erosion around bridges with installed scour countermeasures. Hence, a design hydrograph was derived that could be used as input data in the hydraulic model for the investigation of the bridge scour dynamics within the project and a preliminary methodology is proposed to be applied. The results indicate that bivariate frequency analysis can be very sensitive to the selected baseflow separation methodology. Therefore, future studies should test multiple baseflow separation methods and visually inspect the performance.