We used the Poly-Hydro model to assess the main hydrological components of the snow-ice melt driven Maipo River in Chile, and glaciers' retreat under climate change therein until 2100. We used field data of ice ablation, ice thickness, weather and hydrological data, and precipitation from TRMM. Snow cover and temperature were taken from MODIS. We forced the model using weather projections until 2100 from three GCMs from the IPCC AR5, under three different radiative concentration pathways (RCPs 2.6, 4.5, 8.5). We investigated trends of precipitation, temperature, and hydrology until 2100 in the projection period (PR, 2014-2100) and the whole period (CM 1980-2100, composite), against historical trends in control period (CP, 1980-2013). We found potentially increasing temperature until 2100, except for Spring (OND). In the PR period, yearly flow decreases significantly under RCP85, on average -0.25 m 3 ·s -1 ·year -1 , and down to -0.48 m 3 ·s -1 ·year -1 , i.e., -0.4% year -1 against CP yearly average (120 m 3 s -1 ). In the long run (CM) significant flow decrease would, occur under almost all scenarios, confirming persistence of a historical decrease, down to -0.39 m 3 ·s -1 ·year -1 during CM. Large flow decreases are expected under all scenarios in Summer (JFM) during PR, down to -1.6 m 3 ·s -1 ·year -1 , or -1% year -1 against CP for RCP8.5, due to increase of evapotranspiration in response to higher temperatures. Fall (AMJ) flows would be mostly unchanged, whileWinter (JAS) flows would be projected to increase significantly, up to 0.7 m 3 ·s -1 ·year -1 during 2014-2100, i.e., +0.9% year -1 vs. CP under RCP8.5, due to large melting therein. Spring (OND) flows would decrease largely under RCP8.5, down to -0.67 m 3 s -1 ·year -1 , or -0.4% year -1 vs. CP, again due to evapotranspiration. Glacier down wasting is projected to speed up, and increasingly so with RCPs. Until 2100 ice loss would range from -13% to -49% (-9%, and -39% at 2050) of the estimated volume at 2012, which changed by -24% to -56% (-21%, and -39% at 2050) vs. ice volume in 1982, thus with rapider depletion in the first half of the century. Policy makers will have to cope with modified hydrological cycle in the Maipo River, and greatly decreasing ice cover in the area.

Modelling hydrological components of the Rio Maipo of Chile, and their prospective evolution under climate change / D. Bocchiola, A. Soncini, A. Senese, G. Diolaiuti. - In: CLIMATE. - ISSN 2225-1154. - 6:3(2018 Sep), pp. 57.1-57.27. [10.3390/cli6030057]

Modelling hydrological components of the Rio Maipo of Chile, and their prospective evolution under climate change

A. Senese;G. Diolaiuti
2018-09

Abstract

We used the Poly-Hydro model to assess the main hydrological components of the snow-ice melt driven Maipo River in Chile, and glaciers' retreat under climate change therein until 2100. We used field data of ice ablation, ice thickness, weather and hydrological data, and precipitation from TRMM. Snow cover and temperature were taken from MODIS. We forced the model using weather projections until 2100 from three GCMs from the IPCC AR5, under three different radiative concentration pathways (RCPs 2.6, 4.5, 8.5). We investigated trends of precipitation, temperature, and hydrology until 2100 in the projection period (PR, 2014-2100) and the whole period (CM 1980-2100, composite), against historical trends in control period (CP, 1980-2013). We found potentially increasing temperature until 2100, except for Spring (OND). In the PR period, yearly flow decreases significantly under RCP85, on average -0.25 m 3 ·s -1 ·year -1 , and down to -0.48 m 3 ·s -1 ·year -1 , i.e., -0.4% year -1 against CP yearly average (120 m 3 s -1 ). In the long run (CM) significant flow decrease would, occur under almost all scenarios, confirming persistence of a historical decrease, down to -0.39 m 3 ·s -1 ·year -1 during CM. Large flow decreases are expected under all scenarios in Summer (JFM) during PR, down to -1.6 m 3 ·s -1 ·year -1 , or -1% year -1 against CP for RCP8.5, due to increase of evapotranspiration in response to higher temperatures. Fall (AMJ) flows would be mostly unchanged, whileWinter (JAS) flows would be projected to increase significantly, up to 0.7 m 3 ·s -1 ·year -1 during 2014-2100, i.e., +0.9% year -1 vs. CP under RCP8.5, due to large melting therein. Spring (OND) flows would decrease largely under RCP8.5, down to -0.67 m 3 s -1 ·year -1 , or -0.4% year -1 vs. CP, again due to evapotranspiration. Glacier down wasting is projected to speed up, and increasingly so with RCPs. Until 2100 ice loss would range from -13% to -49% (-9%, and -39% at 2050) of the estimated volume at 2012, which changed by -24% to -56% (-21%, and -39% at 2050) vs. ice volume in 1982, thus with rapider depletion in the first half of the century. Policy makers will have to cope with modified hydrological cycle in the Maipo River, and greatly decreasing ice cover in the area.
Andes; Climate change; Hydrological modelling; Ice down wasting; Atmospheric Science
Settore GEO/04 - Geografia Fisica e Geomorfologia
Settore ICAR/02 - Costruzioni Idrauliche e Marittime e Idrologia
25-giu-2018
Article (author)
File in questo prodotto:
File Dimensione Formato  
Bocchiola et al_2018_Rio Maipo Cile.pdf

accesso aperto

Tipologia: Publisher's version/PDF
Dimensione 15.91 MB
Formato Adobe PDF
15.91 MB Adobe PDF Visualizza/Apri
Bocchiola et al_2018_Rio Maipo Cile-compresso.pdf

accesso aperto

Tipologia: Publisher's version/PDF
Dimensione 1.43 MB
Formato Adobe PDF
1.43 MB Adobe PDF Visualizza/Apri
climate-311533_xAIR.pdf

accesso aperto

Descrizione: Versione bozza finale post-referaggio, accettata dall'Editore per la pubblicazIone
Tipologia: Post-print, accepted manuscript ecc. (versione accettata dall'editore)
Dimensione 3.87 MB
Formato Adobe PDF
3.87 MB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/636543
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 13
  • ???jsp.display-item.citation.isi??? 15
social impact