Climate change is globally recognized as one of the key drivers of degradation of coastal wetland ecosystems, causing considerable alteration of services provided by these habitats. Quantifying the physical impacts of climate change on these services is therefore of utmost importance. Yet, practical work in this field is fragmented and scarce in current literature, especially in developing countries which are likely to suffer most from the adverse climate change impacts. Using a coherent scenario-based approach that combines assessment of physical impacts with economic valuation techniques, here we quantify potential climate change driven losses in the value of wetland ecosystems services due to relative sea-level rise (RSLR)-induced inundation in the vulnerable Western coastal area of Bangladesh in 2100. The results show a small inundation area in 2100 under the three IPCC climate scenarios of RCP2.6 (with 0.25 m of RSLR), RCP6.0 (with 1.18 m of RSLR), and RCP8.5 (with 1.77 m of RSLR) for the coastal wetland ecosystems including the Sundarbans mangrove forest, neritic system and aquaculture ponds. In all scenarios, RSLR will drive a loss in the total value of ecosystem services such as provision of raw materials, and food provision, ranging from US$ 0–1 million to US$ 16.5–20 million, respectively. The outcomes of this study reveal that RSLR-induced inundation on its own, is unlikely to be a major threat to the wetland ecosystems in Western coast of Bangladesh. This would suggest that other climate change impacts such as coastal erosion, increase in frequency of cyclone events, and sea temperature rise might be the likely primary drivers of change in the value of wetland ecosystems services in this area.@en

Climate change impacts threaten the coastal environment and affect Coastal Ecosystem Services (CES) that are vital to human wellbeing. Quantifying the monetary value of climate change driven environmental losses is scarce, especially in coastal areas of developing countries that have low adaptive capacity to climate change impacts. To address this knowledge gap, we present a practical framework to Quantify Climate change driven Environmental Losses (QuantiCEL) that coherently assesses the likely physical impacts of climate change on CES, and pursues the valuation of their losses with primary data collection. The framework is applied to coastal areas in three developing countries, and may serve as a useful guide for practitioners. We quantify potential environmental losses due to relative sea level rise-induced coastal inundation in Indonesia and Bangladesh, and losses due to sea level rise and storm-induced coastline recession in Sri Lanka in the next 100 years. This study illustrates the applicability of the framework in different contexts in the data-scarce developing countries. Our findings suggest that the three case studies will experience the absolute loss value of CES by the end of the 21 st century, with food provision and tourism suffering the highest losses. Moreover, art, amenity, and tourism services are highly affected CES with respect to the percentage loss relative to the present-day value of these CES. The QuantiCEL framework and its application presented in this study could help researchers, policy makers, and coastal zone managers to get better insights into likely climate change driven environmental losses in coastal areas, contributing to the development of much needed environmental risk quantification methods, and sustainable management of coastal wetlands.@en

In predicting storm impacts on sandy coasts, possibly with structures, accurate runup and overtopping simulation is an important aspect. Recent investigations (Stockdon et al., 2014; Palmsten and Splinter, 2016) show that despite accurate predictions of the morphodynamics of dissipative sandy beaches, the XBeach model (Roelvink et al., 2009) does not correctly simulate the individual contributions of set-up, and infragravity and incident-band swash to the wave run-up. In this paper we describe an improved numerical scheme and a different way of simulating the propagation of directionally-spread short wave groups in XBeach to better predict the groupiness of the short waves and the resulting infragravity waves. The new approach is tested against field measurements from the DELILAH campaign at Duck, NC, and against video-derived runup measurements at Praia de Faro, a relatively steep sandy beach. Compared to the empirical fit by Vousdoukas et al. (2012) the XBeach model performs much better for more extreme wave conditions, which are severely underestimated by existing empirical formulations.For relatively steep beaches incident-band swash cannot be neglected and a wave-resolving simulation mode is required. Therefore in this paper we also test the non-hydrostatic, wave-resolving model within XBeach for runup and overtopping against three datasets. Results for a high-quality flume test show non-hydrostatic XBeach predicts the run-up height with good accuracy (maximum deviation 15%). A case with a very shallow foreshore typical for the Belgian coast at Wenduine was compared against detailed measurements. Overall the model shows correct behavior for this case. Finally, the model is tested against a large number (551) of physical model tests of overtopping from the CLASH database. For relatively high overtopping discharges the non-hydrostatic XBeach performs quite well, with increasing accuracy for increasing overtopping rates. However, for relatively low overtopping rates of less than 10-20 l/m/s, the model systematically underestimates measured overtopping rates.

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The complexity of quantifying ecosystem services in monetary terms has long been a challenging issue for economists and ecologists. Many case specific valuation studies have been carried out in various parts of the World. Yet, a coherent review on the valuation of coastal ecosystem services (CES), which systematically describes fundamental concepts, analyzes reported applications, and addresses the issue of climate change (CC) impacts on the monetary value of CES is still lacking. Here, we take a step towards addressing this knowledge gap by pursuing a coherent review that aims to provide policy makers and researchers in multidisciplinary teams with a summary of the state-of-the-art and a guideline on the process of economic valuation of CES and potential changes in these values due to CC impacts. The article highlights the main concepts of CES valuation studies and offers a systematic analysis of the best practices by analyzing two global scale and 30 selected local and regional case studies, in which different CES have been valued. Our analysis shows that coral reefs and mangroves are among the most frequently valued ecosystems, while sea-grass beds are the least considered ones. Currently, tourism and recreation services as well as storm protection are two of the most considered services representing higher estimated value than other CES. In terms of the valuation techniques used, avoided damage, replacement and substitute cost method as well as stated preference method are among the most commonly used valuation techniques. Following the above analysis, we propose a methodological framework that provides step-wise guidance and better insight into the linkages between climate change impacts and the monetary value of CES. This highlights two main types of CC impacts on CES: one being the climate regulation services of coastal ecosystems, and the other being the monetary value of services, which is subject to substantial uncertainty. Finally, a systematic four-step approach is proposed to effectively monetize potential CC driven variations in the value of CES.@en

Climate change triggers major alterations to coastal zones worldwide. Quantification of these adverse impacts to coastal ecosystems is often done on a coarse scale of global regions. Consistent local scale estimates of physical impacts on ecosystems and monetary assessment of associated losses are scarce, especially in developing countries. With aim of facilitating such assessment, which is increasingly required, here we propose a coherent three-step framework and subsequently apply it to quantify potential sea level rise-driven alterations in the monetary value of ecosystem services in the coastal area of Semarang in Indonesia. Within this framework, we (1) quantify the present value of coastal ecosystem services by using economic valuation techniques; (2) identify the potential impacts of relative sea level rise (RSLR)-induced inundation on ecosystem services (for the year 2100 inundation scenarios); and (3) monetize these impacts by developing a novel scenario-based approach. The results show that full inundation (scenario A with 4 m RSLR) poses a median loss of 90% (US$ 2.8 – 3.5) and 25% (US$ 90 – 113) to the present art and fishery values per hectare, while amenity service is expected to lose upto 50% (US$ 3700 – 5400) of its present value. Additionally, recreation value of the coastal ecosystems in three selected sites (Marina and Maron beaches, and Plumbon estuary) will decrease by 70% (US$ 15,460 – 19,820) per hectare. However, in scenario B (RSLR of 1.1 m) with a 50% inundated area, these losses are estimated approximately 40% less than for scenario A. It is expected that researchers and policy makers may apply this approach in their areas of interest to gain a better understanding of the likely costs of sea level rise-driven environmental damages along coasts, ultimately contributing to the sustainable management of coastal environment in Indonesia and possibly in other developing countries.@en