RIO DE JANEIRO, BRAZIL – Chile is closing one of the driest winters in its history with a precipitation deficit ranging between 60 and 80% depending on the country’s different regions: one more year to add to the persistent drought that has plagued the Andean country for more than a decade.
The arrival of spring in Chile opens the way to the melting of precipitation that has been retained in the peaks in the form of ice and snow. This is an essential water supply for the central part of the country, whose water security depends heavily on the accumulation of water in the Andes.
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In this context, it is essential to understand that the glacier contribution is very important for the flow of some rivers, as in the Maipo, which is the supplier of much of the water consumed in the Metropolitan Region of Santiago. A river whose water contribution from glacial melt will be close to 15% when the harsh summer arrives in January, reaching around 40% in February and March.
Chile is among the 30 countries with the highest risk of suffering water shortages. It is estimated that in 2040 it will be the only one in Latin America under this condition of extreme vulnerability, mainly due to deficiencies in the management of the resource, the increase in demand, pollution, the decrease in availability, and environmental damage ecosystems.
According to a study carried out by Cetaqua Chile and commissioned by Aguas Andinas (the sanitation company that supplies the capital and its metropolitan area), the Maipo River Surveillance Board, and the Maipo Canal Canal Society, glacial contributions could fall by up to 75% with respect to current volumes in the summer season (December-March) towards the middle and end of the century.
To face this problem, collaborative work between different entities is essential for finding solutions to mitigate this situation and make better decisions and actions to meet climate change and optimize the management of available water.
According to Eduardo Bustos Sandoval, director of Water Resources at Cetaqua Chile, this scenario of water stress driven by the impacts of climate change in Chile is being aggravated in recent years by an intense drought that has been affecting the country for several years, and that results in a current rainfall deficit for 2021 of around 70%.
Bustos explains that this year the situation continues to be worrying in terms of water availability, since, in addition to the tremendous interannual variability of rainfall, which is mainly concentrated in three months of the year, there has been a significant decrease in rainfall throughout the country, concluding one of the driest winters in living memory, with only 107 mm to date in the city of Santiago.
In this record, however, it is necessary to highlight the past year 2019, where the accumulated precipitation in the whole year barely reached 80 mm in the same city, when the average in a typical year is 340mm: almost an 80% deficit.
To this current precipitation, the deficit must be added the scarce snow deposited on the peaks, which after the frontal system at the beginning of September only reached 43 centimeters at the Laguna Negra station, near the El Yeso Reservoir, an important reservoir and source of water for the Metropolitan Region. In an average year, the accumulation should be approximately 150 centimeters.
This stress on the water resources of this basin is what has led Cetaqua Chile, together with support from other Cetaqua centers in Barcelona and Andalusia, to advance in the development of new tools for forecasting snowmelt volumes in the summer season, which will support the management of water reserves for the city of Santiago, particularly in these years of extreme scarcity.
These advances seek to strengthen the existing forecasting systems, incorporating new variables and uncertainties derived from the changes observed in the climatic conditions of the basin, which also include an increase in the occurrence of extreme phenomena such as high-intensity convective rains and peaks of turbidity in the flows, which in turn condition the availability of resources, explains Bustos.
Through a new project developed for the sanitation company Aguas Andinas, Cetaqua’s research has advanced in analyzing the behavior of current snowmelt flow prediction tools and the development of new complementary tools.
These new developments consider traditional physics-based hydrological models, Artificial Intelligence techniques, the state of snow cover from satellite platforms, and the design of a digital platform that integrates these different tools to support decision making.
These tools seek to simulate and predict the behavior of seasonal flows from the analysis of co-variables such as precipitation observed in the recent period, temperature, and the accumulated snow area in the mountain range at the beginning of the season, says the director of Water Resources of Cetaqua Chile.
The large volume of data incorporated into this predictive system is planned to be integrated into a platform that facilitates its use so that, throughout the summer season, when the demand for water both for consumption and for urban and agricultural uses increases, this platform will support the planning and management of the contributions of the accumulation infrastructure, such as the El Yeso reservoir, to guarantee the availability of water resources throughout the year.
Bustos affirms that although now, these developments have focused on the Maipo River basin, which concentrates almost 40% of the Chilean population, these techniques such as Artificial Intelligence and Big-Data could be applied to the rest of the country’s basins.
To successfully achieve the development of these forecasting tools, Bustos highlights the multidisciplinary vision of the project, which not only focuses on the science of hydrology but also incorporates technical advances such as working with satellite images, big data, and artificial intelligence adjuvants for prediction and decision making.
At the same time, these tools, which emerge from the research work, allow generating valuable inputs for coordination and collaboration between the authorities and the different water users in the basin, particularly in the sanitary and agricultural fields, through the application of new technologies at the service of water resources to ensure the availability of water for different uses.