About the Project
During the past five years, farmers and local governments in Central Chile have been concerned about the severe lack of water for intensive irrigation. They blame it on a series of climate change induced La Niña years, which, due to low sea surface temperatures cause reduced rainfall. In August 2012, the drought in the Limarí Province was declared as a disaster region by the National Government (La Tercera, 2012). Furthermore, it is expected that temperatures will increase during the next decades and annual precipitation rates will be reduced in the context of climate change (Souvignet et al., 2010; Vicuña et al., 2010).
High-elevation mountains play a crucial role in supplying water to arid and semiarid regions, and therefore understanding climate and hydrology feedbacks in mountainous semiarid and arid river basins is essential to be able to predict and control water availability. Water stored in snow and glaciers as in the Himalayas, Rocky Mountains, Alps and Andes provides downstream areas with water during the dry seasons for irrigated agriculture, drinking water supply and hydropower (Barnett et al. 2007). Reliable estimates of current and future climate variability at the regional scale are considered of utmost importance to assess the vulnerability of regional populations to climate change impacts (Christensen et al., 2007). The Limarí River Basin, located in the semiarid Northern Central part of Chile, is an excellent subject for a case study to investigate the climate-hydrology feedbacks in a snowmelt-dominated hydrological system with an annual mean precipitation of only 146 mm (Strauch et al., 2009). The dependence on glacier and snow contributions to surface waters makes this region and its population extremely vulnerable to climate change impacts (Barnett et al. 2007, Bates et al. 2008).
Data on snow, glacier and rock glacier coverage are scarce and only few satellite images of low resolution allow estimations regarding their volume (Favier et al., 2009). Hence the role of snow cover dynamics and the cryosphere in the Andean Cordillera for the basin’s hydrology is not yet sufficiently understood (Azócar & Brenning, 2010; Brenning et al 2005; Vicuña et al., 2010).
According to available regional studies on climate, hydrology and predicted climate change impacts, the feedbacks between precipitation, temperature, snow cover and melting processes on the one hand and springtime runoff during the melting period on the other are not sufficiently understood (Souvignet et al., 2010; Vicuña et al., 2010; Favier et al., 2009). This suggests a strong research need to investigate this complex system of cryosphere, hydrosphere and climate in order to be able to understand and predict future water availability for the high irrigation water requirements in the study area.
Increase of water demand
The enlargement of intensively used agricultural land is increasing the water demand in the Limari-Basin and a strong expansion of the cultivated and irrigated area during the past 20 years can be observed.
Hence, the available irrigation water hence needs to be allocated in the most efficient manner possible. Losses in irrigation infrastructure due to infiltration, evaporation and robbery still account for up to 50% in some canals. Therefore a potent monitoring and information system for the irrigation scheme is needed to detect and reduce water losses.
References and further reading:
AZÓCAR, G.F. & BRENNING, A. (2010): "Hydrological and geomorphological significance of rock glaciers in the dry Andes, Chile (27°/33°S)", Permafrost and Periglacial Processes, vol. 21, no. 1, pp. 42-53.
BARNETT, T. P.; ADAM, J. C. and LETTENMAIER, D. P. (2005): Potential impacts of a warming climate on water availability in snow-dominated regions, Nature 438, 303-309, doi:10.1038/nature04141.
BATES, B.C.; KUNDZEWICZ, Z.W.; WU, S. and PALUTIKOV, J.P. (2008): Climate Change and Water, Technical Paper of the Intergovernmental Panel on Climate Change, Geneva, IPCC Secretariat.
BRENNING A. (2005): Geomorphological, hydrological and climatic significance of rock glaciers in the Andes of Central Chile (33–35-S). Permafrost and Periglacial Processes 16: 231–240. DOI: 10.1002/ppp.528.
CHRISTENSEN J.H., HEWISTON B., BUSUIOC A., CHEN A., GAO X., HELD I., JONES RG., KOLLI RK., KWON-W-T., LAPRISE R., MAGANA RUEDA V.O., MEARNS L.O., MENEDEZ C.G., RÄISÄNEN J., RINKE A., SARR A., WHETTON P. (2007): Regional Climate Projections. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate Change 2007: The Physical Science Basis. Cambridge University Press, Cambridge, UK, p 848-926.
FAVIER, V., FALVEY, M., RABATEL, A., PRADERIO, E. and D. LÓPEZ (2009): Interpreting discrepancies between discharge and precipitation in high-altitude area of Chile’s Norte Chico region (26–32°S), Water Resources Research, 45, W02424, doi:10.1029/2008WR006802.
La Tercera (2012): Gobierno decreta zona de catástrofe a diez comunas de Región de Coquimbo por situación hídrica, http://www.latercera.com/noticia/nacional/2012/08/680-476613-9-gobierno-decreta-zona-de-catastrofe-a-diez-comunas-de-region-de-coquimbo-por.shtml, accessed on 7th of August 2012.
SOUVIGNET, M., GAESE, H., RIBBE, L., KRETSCHMER, N. & OYARZUN, R., (2010): Statistical downscaling of precipitation and temperature in north-central Chile: an assessment of possible climate change impacts in an arid Andean watershed, Hydrological Sciences Journal, vol. 55, no. 1, pp. 41-57.
STRAUCH, G., OYARZUN, R., REINSTORF, F., OYARZUN, J., SCHIRMER, M. and KNÖLLER, K. (2009): Interaction of water components in the semi-arid Huasco and Limarí river basins, North Central Chile, Advances in Geosciences, 22, pp. 51–57.
VICUñA, S., GARREAUD R.D. & MC PHEE, J. (2010): "Climate change impacts on the hydrology of a snowmelt driven basin in semiarid Chile", Climatic Change, vol. 105, no. 3-4, pp. 469-488.