Does the weighting of climate simulations result in a better quantification of hydrological impacts?
<p>With the increase in the number of available global climate models (GCMs), pragmatic questions come up in using them to quantify climate change impacts on hydrology: is it necessary to unequally weight GCM outputs in the impact studies, and if so, how should they be weighted? Some weighting...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-09-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | https://www.hydrol-earth-syst-sci.net/23/4033/2019/hess-23-4033-2019.pdf |
| _version_ | 1818298468288954368 |
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| author | H.-M. Wang J. Chen C.-Y. Xu C.-Y. Xu H. Chen S. Guo P. Xie X. Li |
| author_facet | H.-M. Wang J. Chen C.-Y. Xu C.-Y. Xu H. Chen S. Guo P. Xie X. Li |
| author_sort | H.-M. Wang |
| collection | DOAJ |
| description | <p>With the increase in the number of available global climate models (GCMs), pragmatic questions come up in using them to quantify climate change impacts on hydrology: is it necessary to unequally weight GCM outputs in the impact studies, and if so, how should they be weighted? Some weighting
methods have been proposed based on the performances of GCM simulations with respect to reproducing the observed climate. However, the process from
climate variables to hydrological responses is nonlinear, and thus the
assigned weights based on performances of GCMs in climate simulations may
not be correctly translated to hydrological responses. Assigning weights to
GCM outputs based on their ability to represent hydrological simulations is
more straightforward. Accordingly, the present study assigns weights to GCM
simulations based on their ability to reproduce hydrological characteristics
and investigates their influences on the quantification of hydrological
impacts. Specifically, eight weighting schemes are used to determine the
weights of GCM simulations based on streamflow series simulated by a lumped
hydrological model using raw or bias-corrected GCM outputs. The impacts of
weighting GCM simulations are investigated in terms of reproducing the
observed hydrological regimes for the reference period (1970–1999) and
quantifying the uncertainty of hydrological changes for the future period (2070–2099). The results show that when using raw GCM outputs to simulate streamflows, streamflow-based weights have a better performance in
reproducing observed mean hydrograph than climate-variable-based weights.
However, when bias correction is applied to GCM simulations before driving
the hydrological model, the streamflow-based unequal weights do not bring
significant differences in the multi-model ensemble mean and uncertainty of
hydrological impacts, since bias-corrected climate simulations become rather
close to observations. Thus, it is likely that using bias correction and
equal weighting is viable and sufficient for hydrological impact studies.</p> |
| first_indexed | 2024-12-13T04:35:48Z |
| format | Article |
| id | doaj.art-a29b121ed69d4a9d8711f57ed24b097e |
| institution | Directory Open Access Journal |
| issn | 1027-5606 1607-7938 |
| language | English |
| last_indexed | 2024-12-13T04:35:48Z |
| publishDate | 2019-09-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Hydrology and Earth System Sciences |
| spelling | doaj.art-a29b121ed69d4a9d8711f57ed24b097e2022-12-21T23:59:26ZengCopernicus PublicationsHydrology and Earth System Sciences1027-56061607-79382019-09-01234033405010.5194/hess-23-4033-2019Does the weighting of climate simulations result in a better quantification of hydrological impacts?H.-M. Wang0J. Chen1C.-Y. Xu2C.-Y. Xu3H. Chen4S. Guo5P. Xie6X. Li7State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, 430072, ChinaState Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, 430072, ChinaState Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, 430072, ChinaDepartment of Geosciences, University of Oslo, Oslo, NorwayState Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, 430072, ChinaState Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, 430072, ChinaState Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, 430072, ChinaState Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, 430072, China<p>With the increase in the number of available global climate models (GCMs), pragmatic questions come up in using them to quantify climate change impacts on hydrology: is it necessary to unequally weight GCM outputs in the impact studies, and if so, how should they be weighted? Some weighting methods have been proposed based on the performances of GCM simulations with respect to reproducing the observed climate. However, the process from climate variables to hydrological responses is nonlinear, and thus the assigned weights based on performances of GCMs in climate simulations may not be correctly translated to hydrological responses. Assigning weights to GCM outputs based on their ability to represent hydrological simulations is more straightforward. Accordingly, the present study assigns weights to GCM simulations based on their ability to reproduce hydrological characteristics and investigates their influences on the quantification of hydrological impacts. Specifically, eight weighting schemes are used to determine the weights of GCM simulations based on streamflow series simulated by a lumped hydrological model using raw or bias-corrected GCM outputs. The impacts of weighting GCM simulations are investigated in terms of reproducing the observed hydrological regimes for the reference period (1970–1999) and quantifying the uncertainty of hydrological changes for the future period (2070–2099). The results show that when using raw GCM outputs to simulate streamflows, streamflow-based weights have a better performance in reproducing observed mean hydrograph than climate-variable-based weights. However, when bias correction is applied to GCM simulations before driving the hydrological model, the streamflow-based unequal weights do not bring significant differences in the multi-model ensemble mean and uncertainty of hydrological impacts, since bias-corrected climate simulations become rather close to observations. Thus, it is likely that using bias correction and equal weighting is viable and sufficient for hydrological impact studies.</p>https://www.hydrol-earth-syst-sci.net/23/4033/2019/hess-23-4033-2019.pdf |
| spellingShingle | H.-M. Wang J. Chen C.-Y. Xu C.-Y. Xu H. Chen S. Guo P. Xie X. Li Does the weighting of climate simulations result in a better quantification of hydrological impacts? Hydrology and Earth System Sciences |
| title | Does the weighting of climate simulations result in a better quantification of hydrological impacts? |
| title_full | Does the weighting of climate simulations result in a better quantification of hydrological impacts? |
| title_fullStr | Does the weighting of climate simulations result in a better quantification of hydrological impacts? |
| title_full_unstemmed | Does the weighting of climate simulations result in a better quantification of hydrological impacts? |
| title_short | Does the weighting of climate simulations result in a better quantification of hydrological impacts? |
| title_sort | does the weighting of climate simulations result in a better quantification of hydrological impacts |
| url | https://www.hydrol-earth-syst-sci.net/23/4033/2019/hess-23-4033-2019.pdf |
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