@article{22529,
  abstract     = {Mountainous catchments cover a broad range of elevations and their response to a warming climate is expected to vary significantly in space. Nevertheless, studies on climate change impacts typically examine the changes in flow statistics only at the catchment outlet. In this study, we instead demonstrate the high variability of the hydrological response to climate change at the sub-catchment scale, investigating in detail the contribution of all components of the hydrological cycle in two mountainous catchments (Thur and Kleine Emme) in the Swiss Alps. The analysis was conducted with a two-dimensional weather generator model that simulated gridded climate variables at an hourly and 2-km resolution until the end of the 21st century for the RCP8.5 emission scenario. The climate ensemble was used as input into a distributed hydrological model to estimate the changes in hydrological processes at 100-m and hourly resolutions. Climate models show that precipitation intensifies during winter but weakens during summer in the order of ± 5–10% toward the end of the century. Temperature will rise by up to 4°C, leading to a 50% reduction in snowmelt, 10% increase in evapotranspiration, and shift in precipitation type from snowfall to rainfall. As a result, streamflow is projected to increase by 40% in winter but decrease by 20% to 40% during summer, with winter floods becoming more frequent. The changes to streamflow (mean and extreme low and high flows) at the sub-catchments show a strong dependency with elevation. In contrast to the small changes projected at the outlet of the catchments, streamflow shows a reduction at higher elevations (up to −20% change in mean streamflow for sub-catchments at elevations exceeding 1400 m) and an increase at lower elevations (up to +5% for Kleine Emme and +20% for the Thur at elevations below 600 m). These impacts are tied to the changes in precipitation, as well as changes in snowmelt (at high elevation) and evapotranspiration (at low elevation). The results reveal the causes and diversity of hydrological response to climate change, emphasizing the importance of investigating the distributed impacts of climate change in mountainous environments.},
  author       = {Moraga, Jorge Sebastián and Peleg, Nadav and Fatichi, Simone and Molnar, Peter and Burlando, Paolo},
  issn         = {1879-2707},
  journal      = {Journal of Hydrology},
  keywords     = {Catchment modelling, Climate change impacts, Weather generator, Distributed hydrological model, Streamflow extremes, Hydrological response},
  publisher    = {Elsevier},
  title        = {{Revealing the impacts of climate change on mountainous catchments through high-resolution modelling}},
  doi          = {10.1016/j.jhydrol.2021.126806},
  volume       = {603},
  year         = {2021},
}

@article{22510,
  abstract     = {This study advances mechanistic interpretation of predictability challenges in hydro-geomorphology related to the role of soil moisture spatial variability. Using model formulations describing the physics of overland flow, variably saturated subsurface flow, and erosion and sediment transport, this study explores (1) why a basin with the same mean soil moisture can exhibit distinctly different spatial moisture distributions, (2) whether these varying distributions lead to non-unique hydro-geomorphic responses, and (3) what controls non-uniqueness in relation to the response type. Two sets of numerical experiments are carried out with two physically-based models, HYDRUS and tRIBS+VEGGIE+FEaST, and their outputs are analyzed with respect to pre-storm moisture state. The results demonstrate that distinct spatial moisture distributions for the same mean wetness arise because near-surface soil moisture dynamics exhibit different degrees of coupling with deeper-soil moisture and the process of subsurface drainage. The consequences of such variations are different depending on the type of hydrological response. Specifically, if the predominant runoff response is of infiltration excess type, the degree of non-uniqueness is related to the spatial distribution of near-surface moisture. If runoff is governed by subsurface stormflow, the extent of deep moisture contributing area and its “readiness to drain” determine the response characteristics. Because the processes of erosion and sediment transport superimpose additional controls over factors governing runoff generation and overland flow, non-uniqueness of the geomorphic response can be highly dampened or enhanced. The explanation is sediment composed by multi-size particles can alternate states of mobilization or surface shielding and the transient behavior is inherently intertwined with the availability of mobile particles. We conclude that complex nonlinear dynamics of hydro-geomorphic processes are inherent expressions of physical interactions. As complete knowledge of watershed properties, states, or forcings will always present the ultimate, if ever resolvable, challenge, deterministic predictability will remain handicapped. Coupling of uncertainty quantification methods and space-time physics-based approaches will need to evolve to facilitate mechanistic interpretations and informed practical applications.},
  author       = {Kim, Jongho and Dwelle, M. Chase and Kampf, Stephanie K. and Fatichi, Simone and Ivanov, Valeriy Y.},
  issn         = {0309-1708},
  journal      = {Advances in Water Resources},
  keywords     = {Soil moisture, Spatial heterogeneity, Hydrological response, Geomorphic response, Non-uniqueness, Hydraulic connectivity},
  pages        = {73--89},
  publisher    = {Elsevier},
  title        = {{On the non-uniqueness of the hydro-geomorphic responses in a zero-order catchment with respect to soil moisture}},
  doi          = {10.1016/j.advwatres.2016.03.019},
  volume       = {92},
  year         = {2016},
}