Large‐scale comparison of flow‐variability dampening by lakes and wetlands in the landscape

Abstract

Considering the potential of wetlands to dampen temporal variability of water flow through the landscape, they are increasingly considered as possible nature‐based solutions to mitigate risks of flooding and drought. In this study, we investigate flow variability by means of a flow dampening factor and use observation data from 1984 to 2013 for 82 Swedish catchments to statistically and comparatively analyze the large‐scale effects on this factor of multiple wetlands and lakes in the landscape. The results show good correlation between large‐scale flow dampening and relative area of lakes and floodplain wetlands within a catchment. An increase in relative area up to around 15% for lakes and 0.5% for floodplain wetlands lowers the temporal standard deviation of runoff (R) to around 10%–15% of that for precipitation (P), compared with a common flow‐variability dampening of around 35% for catchments with lake‐wetland area close to zero. Further increase in these relative areas, or in those of wetland types other than floodplain wetlands, has little or no flow dampening effect. The results indicate that the large‐scale flow dampening effect of lakes and floodplain wetlands is mainly due to their water‐storage capacity and less due to their possible effects on the partitioning of P between R and evapotranspiration. Overall, the results emphasize the importance of accounting for the problem scale and relative water‐storage capacity of wetlands when considering their large‐scale efficiency as possible nature‐based solutions for large‐scale flow‐variability regulation in whole catchments.

Solute evidence for hydrological connectivity of geographically isolated wetlands

“…As with any other landscape element, GIWs influence the physical and chemical integrity of downstream waters in proportion to their extent. Consequently, small or negligible wetland contributions to large‐scale ecosystem services, such as flow‐variability regulation (Quin & Destouni, ) or nutrient retention (Quin, Jaramillo, & Destouni, ), can be evident. However, GIW contributions to catchment ecosystem services may be difficult to detect empirically, which underscores the need for studies to quantify and upscale both the magnitude and the timing of flows but also their additive and interactive effects.…”

“…This requires combining our relative runoff generation metrics with estimates of GIW density and subcatchment sizes, which are largely unknown. Although GIWs can occupy large fractions of some landscapes (e.g., Cohen et al, ; Vanderhoof, Alexander, & Todd, ), this is not always the case (e.g., Quin et al, ; Quin & Destouni, ), and the cumulative effect of GIWs will be enormously influenced by their prevalence. Perhaps more importantly, the cumulative effects of multiple wetlands in complexes (i.e., adjacent, though not always flow connected) need attention (Ameli & Creed, ; Thorslund et al, ).…”

Soil-Related Sustainable Development Goals: Four Concepts to Make Land Degradation Neutrality and Restoration Work

“…They do so to solve a whole range of problems, from the maintenance of biodiversity and the restoration of ecosystems, to the design of solutions to cope with climate change and to produce food sustainably [54]. The Sand Engine [55] and the 'Room for the River' [56] projects are good examples of the success of the implementation of this concept as well as natural attenuation as part of risk reduction measures in the management of groundwater pollution [57]. Some essential aspects to consider when designing NBS are: the level of intervention and its 'naturalness' (from minimal interventions to designing artificial ecosystems), the scale of the intervention (from plot scale to whole landscapes), and the complexities this brings in both the natural and socio-economic realms, proper stakeholder engagement, trade-offs, multi-and transdisciplinary knowledge, and mutual learning [54,58,59].…”

Nature‐based solutions for meeting environmental and socio‐economic challenges in land management and development

“…Thorslund et al () and Quin and Destouni () investigate how prevalence, creation, or restoration of wetlands of different types may function as a large‐scale NBS approach to meeting various social–ecological challenges such as mitigating water pollution and/or the temporal flow variability leading flooding hazards in the landscape. Thorslund et al () studied 260 geographically isolated wetlands across North America to understand their hydrological connectivity with the surrounding landscape, which may affect wetland functioning and associated ecosystem services in various ways.…”

“…Their results suggest that geographically isolated wetlands are indeed hydrologically connected and should, as such, be increasingly considered and valued for their potential to provide many ecosystem services. Quin and Destouni () studied long‐term data for 82 Swedish hydrological catchments and the wetlands within these. Their results show that the lakes and floodplain wetlands in these catchments are important for regulating and dampening the temporal variability of water flow through the catchment landscapes.…”