Climate change is projected to alter river flows and the magnitude/frequency characteristics of floods and droughts. Ecosystem-based adaptation highlights the interdependence of human and natural systems, and the potential to buffer the impacts of climate change by maintaining functioning ecosystems that continue to provide multiple societal benefits. Natural flood management (NFM), emphasising the restoration of innate hydrological pathways, provides important regulating services in relation to both runoff rates and water quality and is heralded as a potentially important climate change adaptation strategy. This paper draws together 25 NFM schemes, providing a meta-analysis of hydrological performance along with a wider consideration of their net (dis) benefits. Increasing woodland coverage, whilst positively linked to peak flow reduction (more pronounced for low magnitude events), biodiversity and carbon storage, can adversely impact other provisioning service-especially food production. Similarly, reversing historical land drainage operations appears to have mixed impacts on flood alleviation, carbon sequestration and water quality depending on landscape setting and local catchment characteristics. Wetlands and floodplain restoration strategies typically have fewer disbenefits and provide improvements for regulating and supporting services. It is concluded that future NFM proposals should be framed as ecosystem-based assessments, with trade-offs considered on a case-by-case basis.
Habitat Type: WS
Watersheds
Nature-based solutions (NBS) in river landscapes, such as restoring floodplains, can not only decrease flood risks for downstream communities but also provide co-benefits in terms of habitat creation for numerous species and enhanced delivery of diverse ecosystem services. This paper aims to explore how landscape planning and governance research can contribute to the identification, design and implementation of NBS, using the example of water-related challenges in the landscape of the Lahn river in Germany. The objectives are (i) to introduce the NBS concept and to provide a concise definition for application in planning research, (ii) to explore how landscape planning and governance research might support a targeted use and implementation of NBS, and (iii) to propose an agenda for further research and practical experimentation. Our methods include a focused literature review and conceptual framework development. We define NBS as actions that alleviate a well-defined societal challenge (challenge-orientation), employ ecosystem processes of spatial, blue and green infrastructure networks (ecosystem processes utilization), and are embedded within viable governance or business models for implementation (practical viability). Our conceptual framework illustrates the functions of NBS in social-ecological landscape systems, and highlights the complementary contributions of landscape planning and governance research in developing and implementing NBS. Finally, a research and experimentation agenda is proposed, focusing on knowledge gaps in the effectiveness of NBS, useful approaches for informed co-design of NBS, and options for implementation. Insights from this paper can guide further studies and support testing of the NBS concept in practice
Nature-based solutions (NBS) are usually defined as complementary or alternative solutions to “grey infrastructures” (traditionally made with cement) aimed at conserving and regenerating the functionality of natural and semi-natural ecosystems. The research to date shows a considerable potential of NBS to address the current challenges related to climate change and geo-hydrological risks. Despite significant interest in NBS by researchers and practitioners, knowledge concerning their practical implementation, monitoring, and evaluation is still lacking. This is particularly true for large-scale NBS. The present paper discusses how such solutions can be implemented in the context of hydro-meteorological risk reduction in small Mediterranean catchments with a strong tourist vocation. The work presented here is situated within the RECONECT Project (Regenerating ECOsystems with Nature-based solutions for hydro-meteorological risk rEduCTion), which aims to contribute to a European reference framework on NBS by demonstrating, upscaling, and replicating large-scale NBS in rural and natural areas. The Italian case study of RECONECT is the Portofino Natural Regional Park, which represents a unique natural landscape element with high ecologic, social, and economic (touristic) value, which is threatened by a range of geo-hydrological hazards, such as flash floods, hyper-concentrated floods, shallow landslides, rockfalls, and storm surges. This paper also presents details of NBS interventions in two pilot catchments (San Fruttuoso and Paraggi) visited by thousands of tourists throughout the year. It addresses some of the key aspects related to monitoring meteorological and hydrological processes, as well as remote sensing activities (i.e., LiDAR surveys), which are necessary for the identification of critical-instability areas along waterways and the reconstruction of dry stone walls. Lastly, a discussion of relevant mitigation and adaptation strategies that are potentially replicable at national and international levels is also provided.
We elevate the undervalued role of wetland protective services for mitigating disastrous consequences of unprecedented weather-related events for human communities. Scientific evidence increasingly reveals that wetlands play critical hydrologic roles in landscapes, helping to mitigate flood, drought, and, in some cases, fire risks. However, wetland protective services have not received sufficient policy action. We propose national wetland commissions, modeled after the concept of lake and river commissions, as one way to strategically link wetland protection to other societal objectives, including human disaster risk planning, infrastructure investments, and climate adaptation strategies. We offer an example applicable to the United States, describing an institutional design for a National Interagency Wetland Commission. We suggest it could be patterned after existing federal commissions statutorily created by Congress with delegated administrative and regulatory authority and designated independent agency status within the executive branch. It is time for bold and innovative policy action to incorporate wetland protective services into societies’ defenses against extreme weather events.
Water resources management requires policy enforcement in a changing environment. Climate change must be considered in major watershed river restorations in Korea. The aim of river restorations is to provide better water resource control – now and in the future. To aid in policy making in the government sector, ‘vulnerability-resilience indexes’ (VRIs) with a Delphi survey method have been adopted to provide a possible reference. The Delphi survey offers prioritized vulnerability proxy variables based on expert opinions regarding the changing environment in terms of climate change and river restorations. The VRIs of watersheds were improved after river restorations, with the exception of some locations. However, when climate change was taken into consideration in the analysis of conditions after the restorations were completed, the results showed that governments need to provide better mitigation strategies to increase vulnerability resilience in the face of climate change.
Adaptation to climate change has become a more serious concern as IPCC assessment reports estimate a rise of up to 2 degrees C in average global temperatures by the end of the century. Several recently published studies have underlined the importance of forest management in mitigating the impacts of climate change and in supporting the adaptation capacity of the ecosystem. This study focuses on the role of water-related forest services in this adaptation process. The effects of forestry practices on streamflow can best be determined by paired watershed analysis. The impact of two cutting treatments on runoff was analyzed by a paired experimental watershed study in the Belgrade Forest and the results were evaluated in relation to similar experiments conducted around the world. Forest thinning treatments at 11% and 18% were carried out in a mature oak-beech forest ecosystem over different time periods. Although the thinning increased the runoff statistically, the amount of surplus water remained <5% of the annual water yield. Evidently, the hydrologic response of the watersheds was low due to the reduced intensity of the timber harvest. Finally, the results were combined with those of global studies on thinning, clearcutting and species conversion with the aim of formulating management options for adaptation.
This paper combines hydrological observations and modelling results of a semi arid catchment in Brazil that could lead to a better understanding of the hydrology of similar catchments in semi-arid regions. The Tapacura catchment (area 470.5 km(2)) in the Northeast of Brazil was selected for this study. The Distributed Catchment Scale Model, DiCaSM, was calibrated and validated for the stream flows of the Tapacura catchment. The model performance was further tested by comparing simulated and observed scaled soil moisture. The results showed the ability of the model to simulate the stream flow and the scaled soil moisture. The simulated impacts of climate change of low emission (B1) scenarios, on the worst perspective, indicated the possibility of reduction in surface water availability by -13.90%, -22.63% and -.32.91% in groundwater recharge and by -4.98%, -14.28% and -20.58% in surface flows for the time spans 20102039, 2040-2069, 2070-2099, respectively. This would cause severe impacts on water supply in the region. Changing the land use, for example by reforestation of part of the catchment area which is currently arable land, would lead to a decrease in both groundwater recharge by -4.2% and stream flow by -2.7%. Changing land use from vegetables to sugar cane would result in decreasing groundwater recharge by almost -11%, and increasing stream flow by almost 5%. The combination of possible impacts of climate change and land use requires a proper plan for water resources management and mitigation strategies.
Large-scale vegetation restoration and climate change triggered a significant decline in runoff in the middle reaches of the Yellow River and its tributaries. This runoff decline intensifies inherent water shortage and results in more severe water use conflicts that are threatening sustainable development in the Loess Plateau. Innovative strategies for more water-efficient land management are essential. To this end, the factors controlling runoff were investigated using the upstream area of the Jing River as an example. Runoff was found to be mainly controlled by evaporative demand, precipitation, and land cover type. Budyko’s frameworks were applied to predict the annual and long-term runoff; however, the effect of changes in land management (e.g., afforestation) on runoff cannot be assessed due to lack of vegetation factors. Therefore, an empirical analysis tool was derived based on an existing relationship for runoff estimation. This method was found to be more effective in reproducing the annual and long-term runoff than others. The incorporation of temporal changes in land cover and form in approach enables the estimation of the possible impact of soil conservation measures (e.g., afforestation or terracing). Our study highlights the importance of adaptive land management strategies for mitigating water shortage on the Loess Plateau.
This study analyzes effects of soil and water conservation (SWC) on soil quality and implications to climate change adaptation and mitigation in the Upper Blue Nile River Basin of Ethiopia by using the Anjeni watershed as a case study site. Disturbed and undisturbed soil samples were collected from two sub-watersheds of Anjeni: the Minchet sub-watershed (with SWC measures) and the Zikrie sub-watershed (without SWC measures). Soil samples were taken from 30-cm depth from five representative landscape positions and analyzed following the standard soil lab analysis procedures. The results show that soils from the conserved sub-watershed had improved quality indicators compared with those from the non-conserved site. Significant improvement due to SWC measures was observed in the soil hydrological [total moisture content (+5·43%), field capacity (+5·35%), and available water capacity (+4·18%)] and chemical [cation exchange capacity (+4·40 cmol(+) kg-1 ), Mg2+ (+1·90 cmol(+) kg-1 ), Na+ (+0·10 cmol(+) kg-1 )] properties. SWC interventions significantly reduced soil erosion by 57–81% and surface runoff by 19–50% in the conserved sub-watershed. Reduction in soil erosion can maintain the soil organic carbon stock, reduce the land degradation risks, and enhance the C sequestration potential of soils. Therefore, adoption of SWC measures can increase farmers’ ability to offset emissions and adapt to climate change. However, SWC measures that are both protective and sufficiently productive have not yet been implemented in the conserved sub-watershed. Therefore, it is important that SWC structures be supplemented with other biological and agronomic measures in conjunction with soil fertility amendments appropriate to site-specific conditions.
The need for credible, salient and legitimate climate change adaptation options in the water sector, which target location specific adaptation requirements, is well recognized. In developing countries, the low-hanging fruit; no-regret options, should be identified with stakeholders and assessed against future changes in water availability and demand, for comparing effectiveness and robustness. Such integrated basin-scale assessments, including reservoir catchment and command areas, can suitably inform adaptation decision-making. In this study, we integrate participatory and modelling approaches for evaluation of reservoir catchment and command area no-regret options addressing water availability and demand in the Kangsabati river basin. Through multi-level stakeholder workshops we identify and prioritize options, followed by evaluation of two reservoir catchment options; check dams and increasing forest cover and three reservoir command options; changing cropping pattern, traditional ponds and waste water reuse, using the Water Evaluation And Planning (WEAP) model. We use four high resolution (~25 km) regional climate model simulations of future climatic factors, along with non-climatic factors affecting water demand, for forcing WEAP. We find that options have varied ability in addressing adaptation requirements. Amongst catchment options, increasing forest cover addresses adaptation requirements more suitably than check dams, while in the command areas we observe mixed abilities of options, leading to the inference that combining complementary options may be a more useful strategy. We conclude by discussing our experiences with this approach in a developing country context, in terms of benefits, limitations, lessons learnt and future research directions.
Process-based restoration aims to reestablish normative rates and magnitudes of physical, chemical, and biological processes that sustain river and floodplain ecosystems. Ecosystem conditions at any site are governed by hierarchical regional, watershed, and reach-scale processes controlling hydrologic and sediment regimes; floodplain and aquatic habitat dynamics; and riparian and aquatic biota. We outline and illustrate four process-based principles that ensure river restoration will be guided toward sustainable actions: (1) restoration actions should address the root causes of degradation, (2) actions must be consistent with the physical and biological potential of the site, (3) actions should be at a scale commensurate with environmental problems, and (4) actions should have clearly articulated expected outcomes for ecosystem dynamics. Applying these principles will help avoid common pitfalls in river restoration, such as creating habitat types that are outside of a site’s natural potential, attempting to build static habitats in dynamic environments, or constructing habitat features that are ultimately overwhelmed by unconsidered system drivers.
Organisations and governments around the globe are developing methodologies to cope with increasing numbers of disasters and climate change as well as implementing risk reducing measures across diverse socio-economic and environmental sectors and scales. What is often overlooked and certainly required for comprehensive planning and programming are better tools and approaches that include ecosystems in the equations. Collectively, these mechanisms can help to enhance societies’ abilities to capture the protective benefits of ecosystems for communities facing disaster and climate risks. As illustrated within this chapter, decision support tools and approaches are clearly improving rapidly. Despite these advancements, factors such as resistance to change, the cautious approach by development agencies, governance structure and overlapping jurisdictions, funding, and limited community engagement remain, in many cases, pre-requisites to successful implementation of ecosystem-based solutions. Herein we provide case studies, lessons learned and recommendations from applications of decision support tools and approaches that advance better risk assessments and implementation of ecosystem-based solutions. The case studies featured in this chapter illustrate opportunities that have been enhanced with cutting edge tools, social media and crowdsourcing, cost/benefit comparisons, and scenario planning mechanisms. Undoubtedly, due to the large areas and extent of exposure to natural hazards, ecosystems will increasingly become a critical part of societies’ overall responses to equitably solve issues of disaster risk reduction and climate change adaptation.
Massive deforestation induced by unplanned urbanization in the hilly watersheds of Brahmaputra basin, India, has led to ecological imbalance and is gradually transforming this basin into a multi-hazard zone. Removal of green cover is also becoming a matter of global concern, as it can accelerate the adverse impacts of climate change. People coming in search of work generally reside in the hills, as they cannot afford the high cost of land in plains. This has led to deforestation of the hilly area and has resulted in increased surface erosion from the upper catchments. Though sediment and water yield from these degraded watersheds could have been minimized by implementing ecologically sustainable management practices (EMPs), such as grass land, forest land and detention pond, poor economic conditions of the people stands in the way of field implementation. On the other hand, major industries, which can be held responsible for emission of greenhouse gases, can be asked to finance greenery development in these hilly watersheds through implementation of selected EMPs to earn carbon credit for them. To convert this concept into reality, the EMP combination must be selected in such a way that it restricts sediment and water yield from the watershed within the permissible limit and maximizes its carbon sequestration capacity at minimum possible cost. Such optimal planning is a prerequisite for preparing an acceptable logical agreement between Government and private companies. Keeping this in mind, an optimization model was developed and applied to a micro watershed of Guwahati to explore its applicability in actual field. The model developed in this study provides most logical carbon credit negotiation, subject to the availability of reliable value of CO2 sequestration for different EMPs.
Declining forest health, climate change, and development threaten the sustainability of water supplies in the western United States. While forest restoration may buffer threats to watershed services, funding shortfalls for landscape-scale restoration efforts limit management action. The hydrologic response and reduction in risk to watersheds following forest restoration treatments could create significant nonmarket benefits for downstream water users. Historic experimental watershed studies indicate a significant and positive response from forest thinning by a reallocation of water from evapotranspiration to surface-water yield. In this study, we estimate the willingness to pay (WTP) for improved watershed services for one group of downstream users, irrigators, following forest restoration activities. We find a positive and statistically significant WTP within our sample of $183.50 per household, at an aggregated benefit of more than $400,000 annually for 2181 irrigators. Our benefit estimate provides evidence that downstream irrigators may be willing to invest in landscape-scale forest restoration to maintain watershed services.
Nature-based approaches to flood risk management are increasing in popularity. Evidence for the effectiveness at the catchment scale of such spatially distributed upstream measures is inconclusive. However, it also remains an open question whether, under certain conditions, the individual impacts of a collection of flood mitigation interventions could combine to produce a detrimental effect on runoff response. A modelling framework is presented for evaluation of the impacts of hillslope and in-channel natural flood management interventions. It couples an existing semidistributed hydrological model with a new, spatially explicit, hydraulic channel network routing model. The model is applied to assess a potential flood mitigation scheme in an agricultural catchment in North Yorkshire, United Kingdom, comprising various configurations of a single variety of in-channel feature. The hydrological model is used to generate subsurface and surface fluxes for a flood event in 2012. The network routing model is then applied to evaluate the response to the addition of up to 59 features. Additional channel and floodplain storage of approximately 70,000m3 is seen with a reduction of around 11% in peak discharge. Although this might be sufficient to reduce flooding in moderate events, it is inadequate to prevent flooding in the double-peaked storm of the magnitude that caused damage within the catchment in 2012. Some strategies using features specific to this catchment are suggested in order to improve the attenuation that could be achieved by applying a nature-based approach.
The aim of the study was to analyse economic costs and benefits of stakeholder-defined adaptation scenarios for the Šumava National Park, the Czech Republic, and to evaluate their impact on the provision of ecosystem services, primarily focusing on ecosystem-based adaptation options which support disaster risk reduction in a broader region. The study utilised an array of approaches, including participatory scenario building, GIS modelling and economic evaluation. Based on a participatory input by local stakeholders, four adaptation scenarios were created, formulating various possibilities of future development in the area as well as potential vulnerabilities and adaptation needs. The scenarios subsequently served as the basis for biophysical modelling of the impacts of adaptation and disaster risk reduction measures on the provision of ecosystem services with the InVEST modelling suite, focusing on climate regulation, water quality and hydropower production. Finally, a cost-benefit analysis was conducted, quantifying management and investment costs of each adaptation scenario, and benefits originating from the provision of previously modelled regulating ecosystem services, together with a supplementary selection of provisioning services. This study serves as an example of combining stakeholder views, biophysical modelling and economic valuation in the cost-benefit analysis of ecosystem-based adaptation and disaster risk reduction, which provides the opportunity to find shared solutions for the adaptation of social-ecological systems to global change.
Landslide hazard can be influenced by natural resource management and rural development related activities, such as forest management, road construction, agricultural practices and river management. Vegetation cover and its utilizations may play a role in mitigating the risk of landsliding. Moreover and above all, it does play a role in mitigating the processes leading to increased landslide hazard, such as gully erosion. Thus, forest management and development are of particular concern. But all people living in mountain areas rely on the soil stability for their livelihoods, and their livelihoods may influence this soil stability. Therefore all related activities have to be done on an appropriate way in order to promote soil and slope stability. To identify best adapted practices in a particular area, to organize spatially the different land uses and to promote the implementation of the identified best practices, the ideal scale is the watershed. It allows addressing upstream-downstream linking issues, such as landslides, and provides a framework for sound land use planning. However, it is not always possible to implement actions exactly with the watershed boundaries. From the lack of knowledge regarding the scientific evidence of the role of forests against landslides to the institutional challenge of implementing watershed scaled policies, many progresses have to be done regarding this issue. But the already existing scientific knowledge, the integrated projects which are already implemented and the results which are obtained are encouraging. Above all, they show that fundamental research, socio-economic levers and institutional development have to be carried out and developed in a sound way, towards a better understanding of all the natural and man-made processes and a better management of all natural resources, in particular water and soil of the mountain areas.
Coastal communities worldwide are faced with climate change effects that include sea level rise and increases in the severity and frequency of storms. We present a framework for coastal adaptation to these impacts in planning efforts, using the landscape of the Toms River-Barnegat Bay ecosystem in New Jersey (eastern coast of United States, 90 km south of New York City) as a case study. This plan is a proof-of-concept, showing that collaborative design can improve the ability of shore regions in many regions to recover from storms and sea level rise if it uses a broad concept of the shore’s ecological and geomorphological structures. Ecological connections are maintained or restored from the sand beach through the tidal bay to the mainland Pine Barrens, allowing species to migrate inland as their ecosystems change over time. This plan also re-envisions shore tourism by attracting visitors to the larger and wider shore area, an approach that can maintain or even increase social and economic activity as sea level changes. Transportation routes connecting the changing shoreline area to inland sites help to integrate social activities throughout the region. Watershed based projects to handle stormwater runoff from severe inland storms are also required. These principles can be applied in any coastal landscape where sea level rise is expected. This approach was fostered and supported by a USHUD program – Rebuild by Design – to incorporate unique, collaborative, architectural and ecological approaches to changing climate and sea level rise in Hurricane Sandy-affected states. These ecological concepts can be adapted for use to maintain biotic and economic processes in threatened coastal communities.