Application of indices for water resource systems stress assessment

Guilherme Todt Cardoso De Faro,Joaquin Ignácio Bonnecarrère Garcia,Mara Regina Samensatto Ramos,Cristiano De Pádua Milagres Oliveira

doi:10.1590/2318-0331.241920180106

Guilherme Todt Cardoso De Faro, Joaquin Ignácio Bonnecarrère Garcia + Show 2 more

Open Access

https://doi.org/10.1590/2318-0331.241920180106

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Journal: RBRH	Publication Date: Jan 1, 2019
Citations: 4	License type: CC BY 4.0

Affiliation: Universidade Brasil, Universidade de São Paulo

Abstract

ABSTRACT This paper aims to present a methodology to conduct a water stress assessment of water resources systems through indices. The proposed methodology was applied to Cantareira System, which is one of the most important water supply systems of São Paulo Metropolitan Region (SPMR). The authors used two indices to support this evaluation: Normalized Deficit Index (NDI) and Normalized Deficit Cumulated (NDC). Both of them consider only the natural flow as the renewable source of water (supply), and account for natural and anthropic uses of this water (demand) as a way to determine the dependence level that the area relies on endogenous and/or exogenous sources of water to meet its needs. To support this assessment, two meteorological drought indices were used as well: the Standardized Precipitation Index (SPI) and Drought Magnitude (DM). The diagnosis of a water supply system, a country, region or even district, based on indices that represent the local water risk, is extremely important not only to bring a better understanding of extreme events, such as droughts and floods, but also to support strategic decision-making process regarding water resources management. This sort of assessment is a useful tool, for instance, in indicating eventual necessity of water storage, such as large reservoirs, or interbasin water transfers, which could improve the water security levels of the study unit.

Highlights

In recent years, many indices and indicators have been developed to quantitatively measure the water fragility of regions, river basins and water-producing systems, as well as to evaluate in detail water stress or scarcity events.The characterization of water stress, carries a relative difficulty, once there are many evaluation criteria, apparently of equal importance, when it comes to approaching the issues related to water management
The Standardized Precipitation Index (SPI), Drought Magnitude (DM), Normalized Deficit Index (NDI) and Normalized Deficit Cumulated (NDC) indices presented in this work were calculated in electronic worksheet models
All data used in this work were obtained from the “Cantareira System’s Monitoring Data” database (SABESP, 2018), complemented by the data provided by the Sanitation Company of São Paulo State (SABESP)

Summary

Introduction

The characterization of water stress, carries a relative difficulty, once there are many evaluation criteria, apparently of equal importance, when it comes to approaching the issues related to water management. The selection of these evaluation criteria can be either a political decision or a scientific (BROWN; MATLOCK, 2011) one. The estimation of current levels of water stress is of fundamental importance, if one considers the need for reliable projections about the severity of future water-related crises, mainly due to climatic variability (OKI et al, 2001). The authors employed the Palmer Drought Severity Index (PDSI); Z of Palmer (Z-index); Rainfall Anomaly Index (RAI); and the Standardized Precipitation Index (SPI)

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