Assessing the Risk of 100-year Freshwater Floods in the Lamprey River Watershed of New Hampshire Resulting from Changes in Climate and Land Use

What is the coastal resource issue the project sought to address? Both the magnitude and frequency of freshwater flooding is on the rise in seacoast NH and around much of New England. In the Great Bay watershed, this is the result of two primary causes: 1) increases in impervious surface stemming from a three-to-four fold increase in developed land since 1962; and 2) changing rainfall patterns in part exemplified by a doubling in the frequency of extreme weather events that drop more than 4 inches of precipitation in less than 48 hours (Wake et al., 2011) over the same time period. Moreover, the size of the 100-year precipitation event in this region has increased 26% from 6.3 inches to 8.5 inches from the mid 1950’s to 2010 (NRCC and NRCS, 2012). One consequence is the occurrence of three 100-year floods measured on the Lamprey River at Packers Falls since 1987, and a fourth if the three days of flooding in March of 2010 had occurred instead in two days (Figure 1). Flooding events are expected to continue to increase in magnitude and frequency as land in the watershed is further developed and climate continues to change in response to anthropogenic forcing (e.g., Hayhoe et el., 2007; IPCC, 2007; Karl et al., 2009). Land use management strategies, in particular low impact development (LID) zoning requirements, are one strategy that communities can employ for increased resiliency to flooding with the greatest influence in urban environments

Planned Adaptation in Design and Testing of Critical Infrastructure: The Case of Flood Safety in The Netherlands

In the Netherlands, dykes and other primary water defence works are assets that are essential to keep the society and economy functioning, by protecting against flooding from sea and rivers due to extreme events. Given that 55% of the country is at risk of flooding, primary water defence works belong to its critical infrastructure. Many factors influence the risk and impact of flooding. Besides physical factors (e.g., landscape design, climate change) also socio-economic factors (e.g., population, assets) are important. Given that these factors change and feature complex and uncertain behaviour in past and future, the design and regulation of this critical infrastructure will have to be flexible enough to be able to deal with such changes. ‘Planned Adaptation’ refers to regulatory programmes that plan for future changes in knowledge by producing new knowledge and revising rules at regular intervals. This study describes the emergence of the next generation of Dutch primary water defence infrastructure, which through the stepwise implementation of Planned Adaptation for design and testing of primary water defence works in the mid-1990s has moved beyond the Delta Works approach of 1953 and subsequent unplanned adaptations. This has prepared the ground for the recent introduction of Adaptive Delta Management, which makes an integral part of the new Delta Plan for the Netherlands that was published on 16 September 2014 and which is also analysed in this study

Beach users’ perceptions of coastal regeneration projects as an adaptation strategy in the western Mediterranean

Some coastal environments facing climate change risks are starting to be managed with nature-based solutions (NBS). Strategies based on the rehabilitation of green infrastructures in coastal municipalities, such as renaturalization of seafronts, are considered adaptive to the effects of climate change but may cause misconceptions that could lead to social conflicts between the tourist sector and the society. A survey was carried out to study user perceptions on the effects of climate change, preferences for adaptation strategies, and the assessment of projects of dune reconstruction. We find that while beach users recognize the benefits of NBS for environmental conservation and storm protection, they show little concern about possible effects of climate change on recreational activity and have limited understanding about the protective capacity of NBS. Thus, a greater effort must be made to better explain the effects of climate change and the potential benefits of NBS in coastal risk management.Peer ReviewedPostprint (author's final draft