Implications of the New Operational Rules for Cantareira Water System: Re-Reading the 2014-2016 Water Crisis

During the 2014-2016 water shortage crisis, the Metropolitan Area of Sao Paulo (MASP) water supply system extracted pumping volume from the Cantareira System. Before the crisis, between 1984 and 2013, the reservoir’s average water extraction flow was 29.6 m3·s-1. During the period of pumping volume usage, the average extraction flow was 16.2 m3·s-1. Following the crisis, two new mitigation policies were implemented: a water extraction Resolution (in 2017) and a Resolution for water reallocation from another basin (in 2018). This study provides a novel investigation of the Cantareira System water crisis by assessing the mitigation policies impacts on storage level dynamics. The system storage level was evaluated using the reservoir simulation module of PDM-Cemaden hydrological model, assuming that the new policies had already been implemented prior to the crisis. A control simulation was run with observed in- and out-flow and operationally-practiced extraction flow. The storage level dynamics impacts were evaluated under 4 water mitigation policies scenarios varying the policies implementation starting date, the extraction flow range and including the water reallocation variable. Results showed that pumping volume would only need extraction during a short period (Scenarios I, III and IV), and considering the water reallocation, pumping volume extraction would not have been necessary (Scenario II). Although the pumping volume would still have been extracted during a short period, water shortage impact would have been lessened, had the policies been already implemented before the crisis. The water mitigation policies implementation supports the reservoirs storage management but does not guarantee that MASP water demand is fully met. Therefore, in order to effectively improve water security, further policies and practices to reduce water demand and enhance supply should be considered.

Hydrologic Monitoring Plan of the Brazilian Water Producer/PCJ Project

Both Ecosystem-based Adaptation (EbA) and Payment for Ecosystem Services (PES) have a wide range of strategies that include different economic instruments for nature conservation. Although the generation and maintenance of payment for hydrologic ecosystem services (Water-PES) is expanding in Brazil, there are difficulties in the implementation of projects. Due to the complexity and non-linearity of the hydrological processes, also affecting both EbA and Water-PES goals, monitoring quali-quantitative aspects of streams have been here addressed as a useful management tool. This study presents the Hydrological Monitoring Plan (HMP) of the Water Producer/PCJ project, operating between 2009-2014, in order to: 1) evaluate the impact of project actions under water quali-quantitative aspects;and 2) promote the incorporation of HMP’s elements in water resources management. HMP of the Water Producer/PCJ project has been implemented following the conditions for efficiency (baseline, long-term scale compatible with the actions of the project, in the experimental and reference watersheds). In addition, HMP is being implemented from upstream to downstream in catchments with areas ranging from 17 to 130 km2. This proposal favors the quantification and valuation of hydrologic services that could be assessed by ecohydrologic monitoring and modeling. Thus, we look forward to the consolidation of the Brazilian information system of water resources, the reduction of modeling uncertainties and integrated assessment of the consequences of land-use/land-cover change that strongly impact goals of EbA and Water-PES initiatives.

R eview of Soil and Water Assessment Tool(SWAT)applications in Brazil:C hallenges and prospects

The geographical extent of Brazil exceeds 8.5 million km2 and encompasses a complex mix of biomes and other environmental conditions.Multiple decision support tools are needed to help support management of these diverse Brazilian natural resources including ecohydrological models.The use of the Soil and Water Assessment Tool(SWAT)ecohydrological watershed-scale model in Brazil has increased greatly during the past decade.Well over 100 SWAT studies were identified in this review which have been published during 1999 to 2015 in Brazilian and international journals,conference proceedings,and as theses or dissertations,many of which are written in Portuguese.The majority of these studies(102 total)are reviewed here as part of an extensive survey covering the 1999 to 2013 time period.Temporal and spatial distributions,a summary of hydrologic calibration and validation results and a synopsis of the types of applications that were performed are reported for the surveyed studies.A smaller subset of recent Brazilian studies published in English between 2012 and 2015 in scientific journals are also reviewed,with emphasis on hydrologic and sediment transport testing results as well as scenario applications that were performed.The majority of the surveyed SWAT studies was performed for watersheds located in the South and Southeast regions of Brazil(67%)and was conducted in the context of academic research.Nearly 50%of the surveyed studies reported only hydrologic results.Similar trends were found for the subset of more recent English publications.Limited studies have been reported that describe applications of SWAT in Brazil by private firms or government agencies;this review indicates that the potential exists for increased numbers of such studies in the future.However,there is evidence that a lack of accessibility to adequate quality input data is a possible hindrance to the more general use of SWAT for watershed applications in Brazil.

Effects of spatial and temporal weather data resolutions on streamflow modeling of a semi-arid basin,Northeast Brazil

One major difficulty in the application of distributed hydrological models is the availability of data with sufficient quantity and quality to perform an adequate evaluation of a watershed and to capture its dynamics.The Soil&Water Assessment Tool(SWAT)was used in this study to analyze the hydrologic responses to different sources,spatial scales,and temporal resolutions of weather inputs for the semi-arid Jaguaribe watershed(73000 km2)in northeastern Brazil.Four different simulations were conducted,based on four groups of weather and precipitation inputs:Group 1-SWAT Weather Generator based on monthly data from four airport weather stations and daily data based on 124 local rain gauges;Group 2-daily local data from 14 weather stations and 124 precipitation gauges;Group 3-Daily values from a global coupled forecast model(NOAA’s Climate Forecast System Reanalysis-CFSR);and Group 4-CFSR data with 124 local precipitation gauges.The four simulations were evaluated using multiple statistical efficiency metrics for four streamflow gauges,using:Nash-Sutcliffe coefficient(NSE),determination coefficient(R2),the ratio of the root mean square to the standard deviation of the observed data(RSR),and the percent bias(PBIAS).The Group 4 simulation performed best overall(provided the best statistical values)with results ranked as“good”or“very good”on all four efficiency metrics suggesting that using CFSR data for weather parameters other than precipitation,coupled with precipitation data from local rain gauges,can provide reasonable hydrologic responses.The second best results were obtained with Group 1,which provided“good”results in three of four efficiency metrics.Group 2 performed worse overall than Groups 1 and 4,probably due to uncertainty related to daily measures and a large percentage of missing data.Groups 2 and 3 were“unsatisfactory”according to three or four of the efficiency metrics,indicating that the choice of weather data is very important.