| Title: | Multimodel assessment of climate change-induced hydrologic impacts for a Mediterranean catchment |
| Authors: | Perra, E., M. Piras, R. Deidda, C. Paniconi, G. Mascaro, E.R. Vivoni, P. Cau, P.A. Marras, R. Ludwig and S. Meyer |
| Year: | 2018 |
| Journal: | Hydrology and Earth System Sciences |
| Volume (Issue): | 22(7) |
| Pages: | 4125-4143 |
| Article ID: | |
| DOI: | 10.5194/hess-22-4125-2018 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic only |
| Primary Application Category: | model and/or data comparison |
| Secondary Application Category: | climate change |
| Watershed Description: | 473 km^2 Rio Mannu drainage area, located in southern Sardinia, Italy. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | This work addresses the impact of climate change
on the hydrology of a catchment in the Mediterranean, a region
that is highly susceptible to variations in rainfall and
other components of the water budget. The assessment is
based on a comparison of responses obtained from five hydrologic
models implemented for the Rio Mannu catchment
in southern Sardinia (Italy). The examined models – CATchment
HYdrology (CATHY), Soil and Water Assessment Tool
(SWAT), TOPographic Kinematic APproximation and Integration
(TOPKAPI), TIN-based Real time Integrated Basin
Simulator (tRIBS), and WAter balance SImulation Model
(WASIM) – are all distributed hydrologic models but differ
greatly in their representation of terrain features and physical
processes and in their numerical complexity. After calibration
and validation, the models were forced with bias-corrected,
downscaled outputs of four combinations of global
and regional climate models in a reference (1971–2000) and
future (2041–2070) period under a single emission scenario.
Climate forcing variations and the structure of the hydrologic
models influence the different components of the catchment
response. Three water availability response variables –
discharge, soil water content, and actual evapotranspiration
– are analyzed. Simulation results from all five hydrologic
models show for the future period decreasing mean annual
streamflow and soil water content at 1m depth. Actual evapotranspiration
in the future will diminish according to four
of the five models due to drier soil conditions. Despite their
significant differences, the five hydrologic models responded
similarly to the reduced precipitation and increased temperatures
predicted by the climate models, and lend strong support
to a future scenario of increased water shortages for this
region of the Mediterranean basin. The multimodel framework
adopted for this study allows estimation of the agreement
between the five hydrologic models and between the
four climate models. Pairwise comparison of the climate and
hydrologic models is shown for the reference and future periods
using a recently proposed metric that scales the Pearson
correlation coefficient with a factor that accounts for systematic
differences between datasets. The results from this
analysis reflect the key structural differences between the
hydrologic models, such as a representation of both vertical
and lateral subsurface flow (CATHY, TOPKAPI, and tRIBS)
and a detailed treatment of vegetation processes (SWAT and
WASIM). |
| Language: | English |
| Keywords: | |