Recent Glacier Retreat in Tropical Andes

Recent glacier retreat in Tropical Andes

Edson RAMIREZ

E. Ramirez1, Y. Asaoka2, F. Rojas1, N. Funes1, Y. Okamura3 1) Instituto de Hidráulica e Hidrología , Universidad Mayor de San Andres , La Paz , Bolivia. 2) Tohoku University 3) JICA - Bolivia Sendai, October 2012 INTRODUCTION

Tropical Glaciers distribution in the world

5% of the world’s mountain glaciers 99% are concentrated in the Andes 70% in Perú, 20% in Bolivia, 10% in the rest Cordillera Real - BOLIVIA

Amazon Andes MOTIVATION

• Tropical Andean Glaciers as water resources • Impact of climate change on water resources • What do we expect for the future?

Tuni Reservoir (Bolivia) Foto:E.Ramirez © Pacific

Ocean COLOMBIA

ECUADOR Ecuador Quito

PERU BRASIL Human consumption water Lima

Irrigation BOLIVIA La Paz

Hydropower generation

CHILE Andes : > 40 M inhabitants. ARGENTINA Atlantic Ocean

Source : Barnett et al., Nature 2005 In recent years, two important trends have been observed in the Central Andes:

• the accelerated glacier retreat • warming of the atmosphere.

Foto:E.Ramirez ©

1975

We will illustrate this trend Huayna Potosí with the case of the Huayna Potosí and Chacaltaya glacier, which looms over the city of La Paz, Bolivia

Chacaltaya

Huayna Potosí

Chacaltaya

Huayna Potosí

Chacaltaya

Huayna Potosí

Chacaltaya

Landsat satellite image Source: (IHH-UMSA) © Chacaltaya Glacier Geographical position: 16º21’S-68º07’W Altitude range: 4700-5396 m Catchment area: 0.52 km2 Glacier area in 2007: 0.003 km2 General exposure: South

Photos: B.Francou (IRD)© E.Ramirez (IHH-UMSA) ©

0 0

-200 -50000

-400 -100000 2010

-600 -150000 antizana 15A antizana15b -200000 -800 yanamarey broggi -1000 pastoruri -250000 uruashraju -1200 Cajap -300000 Cumulative area evolution (m²)

Cumulative length evolution (m) evolution length Cumulative Zongo (area) -1400 Charquini-S (area) -350000 Chacaltaya (area)

-1600 -400000 1930 1940 1950 1960 1970 1980 1990 2000

Ramirez et. al 2001; Journal of Glaciology Foto: E.Ramirez New glacier inventory using Remote Sensing Techniques ALOS: ALOS Advanced Land Observing Satellite

PRISM sensor

ALOS Satellite (Panchromatic Remote-sensing Instrument Japan Aerospace Exploration Agency (JAXA) Tsukuba -Japan. for Stereo Mapping)

PRISM Characteristics Number of 1 (Panchromatic) Bands Wavelength 0.52 to 0.77 micrometers Number of 3 (Nadir; Forward; Optics Backward) Base-to-Height 1.0 (between Forward ratio and Backward view) Spatial 2.5m (at Nadir) Resolution 70km (Nadir only) / 35km Swath Width (Triplet mode) S/N >70 MTF >0.2 28000 / band (Swath Number of Width 70km) Detectors 14000 / band (Swath Width 35km) -1.5 to +1.5 degrees Pointing Angle (Triplet Mode, Cross- track direction) Bit Length 8 bits 3D GLACIER BOUNDARIES

The development of new high resolution sensors mounted on observational satellites with stereoscopic capabilities permits the application of photogrammetric techniques for the precise delimitation of glacier boundaries.

ALOS – PRISM Illampu - 2009 Glacier inventoy for th “Cordillera Real” , updated to 2009

Pixel resolution: 2.5 m THE NEW GLACIER INVENTORY

476 glaciers were identified and digitized using a digital photogrammetric station.

The current glacier surface of the “Cordillera Real” is : 185.5 km2

Comparing with the first glacier inventory of 1980 the surface loss represent 43%

The vertical accuracy of stereo models using this method is ±3m. GRANDE Project

Catchment characteristics

Basin area: 90.39 km2 C Glacier surface: T Condoriri: 1.43 km2 Tuni: 0.56 km2 Huayna West: 1.78 km2

ALOS-AVNIR2 Application Condoriri GLACIERS

LAKES Tuni WETLANDS

Huayna West

ALOS-PRISM-AVNIR2 Application CONDORIRI BASIN Trends in glacier surface Condoriri and Tuni Catchments 3 2.5

) 2 2

1.5

Area (Km 1

0.5

0 1940 1960 1980 2000 2020 2040 2060 Year

TUNI BASIN

1.6

1.4

1.2 ) 2 1

0.8

0.6 Glacier surface losses for the period Area (Km 0.4 1956 – 2009 0.2

Condoriri: 49%, Tuni: 62% 0 1950 1960 1970 1980 1990 2000 2010 2020 2030 Year Huayna Potosi mountain Automatic Weather Station (AWS)

5123 m

LiDAR System Huayna West Zongo glacier glacier LiDAR System

Four essential factors:

• Instrumental effects • Atmospheric effects • The target scattering characteristics • The measurement geometry LiDAR systems equation:

Pr : the received power Pt: the transmitted power Dr : the receiver aperture R: the range, βt : the transmitter beam width. σ: the backscatter cross section Key instrumental factors

DGPS Antena

LiDAR LiDAR Base points

DGPS LiDAR – Digital Surface Models (Huayna Potosí West)

3D Model ICE THICKNESS CHANGES

2007

Glacial front retreat 2011-2012: 20m Climatic variables measurements

Automatic Weather Station 5123 m

Pancho san

SEB: Surface Energy Balance R is the net radiation H and LE are the turbulent fluxes of sensible and latent heat

S↓ is the short-wave irradiance or global radiation, S↑ is the reflected short-wave radiation S = S↓-S↑ is the net short-wave radiation L↓ and L↑ are the long-wave irradiance and emittance, respectively L = L↓ -L↑ is the net long-wave radiation α is the surface albedo, ε is the long-wave emissivity of ice, σ = the Stefan-Boltzmann constant, Ts is the surface temperature. PRELIMINARY RESULTS

Precipitation vs. Accumulation

30 Automatic Weather Station (Huayna West) 115

25 95

20 75 (cm)

(mm)

15 55 Precipitation Accumulation Precipitation 10 35 Accumulation

5 15

0 ‐5 … … … … … … … … … … … … … … … … … … … … 05/06/20 19/06/20 03/07/20 17/07/20 31/07/20 14/08/20 28/08/20 11/09/20 20/12/20 03/01/20 17/01/20 31/01/20 14/02/20 28/02/20 13/03/20 27/03/20 10/04/20 24/04/20 08/05/20 22/05/20 Date

Rainy season Dry season (summer) (winter) PRELIMINARY RESULTS

Precipitation vs. Albedo

30.00 1.20

Precipitation (mm) 25.00 1.00 Albedo

20.00 0.80 (mm)

15.00 0.60 Albedo

Precipitacion 10.00 0.40

5.00 0.20

0.00 0.00 20/12/2011 03/01/2012 17/01/2012 31/01/2012 14/02/2012 28/02/2012 13/03/2012 27/03/2012 10/04/2012 24/04/2012 08/05/2012 22/05/2012 05/06/2012 19/06/2012 03/07/2012 17/07/2012 31/07/2012 14/08/2012 28/08/2012 11/09/2012 Date

Rainy season Dry season High Albedo Low Albedo PRELIMINARY RESULTS

Precipitation vs. R↓ & R↑

1600 30

Short wave irradiance 1400 25 Reflected short‐wave 1200 radiation Precipitation 20 1000 (mm)

(W/m2) 800 Fresh snow 15 (high relection)

Radiation 600 Precipitation 10

400

5 200

0 0

25/05/2011 15/06/2011 06/07/2011 27/07/2011 17/08/2011 07/09/2011 28/09/2011 19/10/2011 09/11/2011 30/11/2011 21/12/2011 Date11/01/2012 01/02/2012 22/02/2012 14/03/2012 04/04/2012 25/04/2012 16/05/2012 06/06/2012 27/06/2012 18/07/2012 08/08/2012 29/08/2012 19/09/2012

Summer Winter (rainy season) (Dry season) PRELIMINARY RESULTS Precipitation vs. Accumulation

40 “El Niño” (Dry)

% “La Niña” (Wet) 0

-20 2011-2012

-40 9 2 6 0 1 7 0 0 4 9 2 2 9 9 2003 200 9 2 9 1 2000 -60 7 8 1991 1 7 9 9 1985 1988 4 6 1 1 6 9 1973 1976 9 2 9 1 1970 4 5 955 1961 1 9 9 1 1958 1 1

30 Automatic Weather Station (Huayna West) 115

25 95

20 75 (cm)

(mm)

Precipitation 15 55 Precipitation Accumulation Accumulation Accumulation Precipitation 10 35

5 15

0 ‐5 … … … … … … … … … … … … … … … … … … … … 20/12/20 03/01/20 17/01/20 31/01/20 14/02/20 28/02/20 13/03/20 27/03/20 10/04/20 24/04/20 08/05/20 22/05/20 05/06/20 19/06/20 03/07/20 17/07/20 31/07/20 14/08/20 28/08/20 11/09/20 Date CONCLUSIONS

• For the new glacier inventory 476 glaciers were identified and digitized.

• The current glacier surface of the “Cordillera Real” is : 185.5 km2

* The glacier surface loss in “Cordillera Real” between 1980 to present is 43%

In Bolivia hydrological year 2011-2012 was identified as a climatic episode "La Niña" characterized by an increase of the amount of precipitations. Huayna Potosi glacier has experienced a maximum accumulation of 1m in ice thickness in the upper part at an altitude of 5,123 m. However the glacier front has experienced a shrinkage of 20m with maximum thickness losses that reached 6m. The results indicate that, under current conditions, Huayna Potosi glacier is probably in a state of imbalance. Thank you very much for your attention.