Management of water resources in Paraguay by using integrated statistical methods applied to hydro-climatic variables

Project leaders

Luciano Telesca, Julián Báez Benítez

Agreement

PARAGUAY - CONACYT-not in force - Consejo Nacional de Ciencias y Tecnología

Call

CNR/CONACYT 2017-2018

Department

Earth system science and environmental technologies

Thematic area

Earth system science and environmental technologies

Status of the project

New

Research proposal

Paraguay is facing enormous challenges to ensure good fresh water quality, equitable access to clean freshwater and protection against water-related hazards such as floods and droughts (Portela et al. 2014b, 2015). Water resources management, including related risks analysis and assessment, plays an important role for the future development of its society. Population needs clean fresh water for production and nutrition, and both are threatened by water related risks. Also the economic sector depends crucially by proper water resource managements. In fact, seasonal climate variability represents the major source of risks in soybean production, which increased dramatically in Paraguay during the last decade posing the country as the fourth largest soybean exporter in the world, producing about 3% of the world's soybean production. Soybean production represents one of the most important income source for Paraguay, therefore the management of water resources and assessment of risk is a key issue for the economic development of the country.
Within this context, the project aims at analysing climatic and hydrologic parameters and assessing their role in relationship with soybean production variation through years in Paraguay at different temporal and spatial scales. This is a research priority for Paraguayan scientific community, and, at a more general scientific scale, it represents one of the societal challenges of the HORIZON2020.
Such investigation will be performed by using robust and advanced statistical methods, since these approaches could help to better understand the dynamical mechanisms underlying the nonlinear and complex interactions among climatic, hydrologic and environmental variables strongly depending on considered spatio-temporal scales. Furthermore, such comprehension is even more challenging if we consider that these interactions influence the agricultural production, like that of soybean in Paraguay.
Thus, several space and time series methods will be used to accomplish the project's objectives: i) from standard ones, like the power spectrum to identify typical periods in the series, ii) to more advanced, like the detrended fluctuation (DFA) analysis and the multifractal-DFA to identify scaling, dynamical crossovers and persistence, important to understand the mechanisms governing hydrologic and climatic processes, iii) to singular spectrum analysis (SSA) to identify the main components in hydro-climatic series more effectively than the usual harmonic Fourier decomposition, iv) to the robust correlogram-based periodogram to identify cycles in short series, like soybean production, that cannot be analysed by standard methods. Drought spatial classification will be investigated by using Principal Component Analysis (PCA) combined with Kernel occurrence rate estimation method coupled with bootstrap confidence band to quantify yearly drought occurrence rates.
Special attention will be devoted to the investigation of drought phenomenon by studying the spatial and temporal variation of two drought indices, the Standard Precipitation Index (SPI) and the Standard Precipitation Evapotranspiration Index (SPEI) that are useful for both: i) the management of water resources, and ii) the assessment of forecasting schemes of water resource availability and extreme-events occurrence. Both the indices are extremely important for their effectiveness in portraying the seriousness of drought and, hence, the shortage of available water.
All above will contribute in elucidating the role of the different forcings affecting the hydrologic regime in Paraguay and clarify its role in affecting soybean production.
The results of the project will have great impact in the comprehension of hydrology of Paraguay. In fact, the deep description of the space-time dynamics of the hydrologic and climatic parameters over the territory of Paraguay will help to better understand the complexity of occurrence of extreme hydrologic events (floods and droughts); in fact, for instance, the relationship between La Nina events and drought events in Paraguay is still a challenge and needs new research that this project will contribute to advance. This, in turn, will help to set up suitable hydrologic models that would contribute in assessing forecasting procedures of severe drought events. Furthermore, this project will advance the comprehension of the impact of climate on soybean production that represents one of the major economic priorities of the country, contributing in developing management tools and strategies for limiting socio-economic impacts linked with severe droughts. The results will be disseminated through intermediate and final technical reports, international conferences and international papers. The activity of the project will be also disseminated on appropriate website in order to share the results with the scientific community.
Added value: This project entails a joint research effort among experts in different disciplines from the two teams. The Paraguayan team consists of specialists of a high qualification with very rich experience in the hydrology of Paraguay; moreover they were involved in EU-funded CapWEM Project focused on water resources engineering and management in Latin America; thus they are the best Paraguayan partner in this water-resource-focused cooperation project. On the other hand, the Italian team has played a key role in advancing research in statistics and time series tools applied to environmental sciences, including hydrology. The synergy between the expertises of the two teams is fundamental to attain the aimed goals of the project, and to envisage their cooperation at EU level for future project submissions. The outcomes of this project (papers, knowledge transfer, staff mobility, exchange of methods and human resources) will open new avenues in the Paraguayan-Italian cooperation in the context of water resources management.

Research goals

The main goal of the proposed research program is to attain a complete vision on the interaction between hydrologic, climatic and economic factors in the context of water resources in Paraguay. Using the available data (rainfall, temperature, streamflow, soybean production) the following specific objectives will be achieved: 1) Identifying the different hydrologic regimes in the investigated area; 2) Identifying the possible characteristic crossovers in the scaling behaviour of the measured hydro-climatic parameters; 3) Producing the Standard Precipitation Index (SPI) series for the sites of major hydrologic interest in Paraguay; 4) Producing the Standard Evapotranspiration Precipitation Index (SPEI) series for the sites of major hydrologic interest in Paraguay; 5) Identifying the main features in terms of correlations, persistence, trend, periodicity in the SPI and SPEI time series; 6) Finding the main dynamical features in the time series of soybean production; 7) Identifying the interactions between hydrologic indices and soybean features and defining their implications in the perspective of water resources availability and drought occurrence.

Last update: 18/04/2024