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Global forest plantations are expanding, causing land-use changes and impacting the water cycle. This study assesses whether eucalyptus plantations reduce groundwater levels compared to grasslands in paired subtropical watersheds. The hydrological dynamics of surface and subsurface water were compared in three small watersheds in southern Brazil, mainly occupied by Eucalyptus saligna (Es-W, 79.9 ha), Eucalyptus benthamii (Eb-W, 82.1 ha), and degraded anthropized natural grassland (G-W, 109.4 ha). Rainfall, flow, and piezometric levels were monitored. Runoff, evapotranspiration, and water balance in the soil profile were estimated, and the subsurface environment was characterized using electrical resistivity tomography. During higher accumulated rainfall, water surplus increased for all watersheds. In the wet period (accumulated rainfall of 1098.0 mm), evapotranspiration was higher for eucalyptus (624.3 mm for Eb-W and 512.5 mm for Es-W) than for the grassland watershed (299.5 mm), resulting in the highest runoff in G-W (649.6 mm). During the dry period (accumulated rainfall of 478.5 mm), water deficit and withdrawal were mainly observed in forested watersheds, decreasing groundwater. Combining water balance and electrical resistivity tomography estimations results in a better understanding of the hydrological dynamics in paired watersheds with different land uses. This information is useful for developing best-practice management strategies for sustainable water resource use and forest production. [ABSTRACT FROM AUTHOR]

The construction of dams and interbasin water transfers are major strategies to adapt to water scarcity. In the semi-arid Jaguaribe basin, Brazil, large strategic reservoirs supply water for urban centres, while farm dams serve multiple demands of rural communities. We used the Model of Water Availability in SemiArid Environments (WASA) to assess the water storage dynamics of strategic reservoirs impacted by: (i) water withdrawal from farm dams located upstream; (ii) interbasin water transfer to the Jaguaribe basin. Simulations show that intensive water use from smaller reservoirs reduces large reservoir volumes by less than 10%, whereas inflows from the São Francisco Integration Project to the basin can increase by 6% the period of time in which reservoir capacity is above the alert volume. The practice of saving water from small dams can be abandoned, enabling higher agricultural production without compromising the water supply of large urban centres. [ABSTRACT FROM AUTHOR]

This paper describes the challenges currently facing Brazil's basic sanitation sector. The sector's characteristic profitability and dynamism have brought State-run Water & Sewage (W&S) services into the spotlight of the structural reform agenda on the argument that governments do not have the resources necessary to universalize coverage. There is a pattern of W&S services' operating with a surplus, which helps explain the intense dispute in recent years in favour of legal changes to the market position of CESBs and local providers to favour an expanding role for private agents. Converging with the structural reform agenda, Law 14,026, sanctioned on 15 July 2020, made far-reaching changes to the legal framework for sanitation and provided for the State's complete withdrawal from the sector. The new regulatory framework prohibited programme contracts, required tender processes for sanitation service contracts, encouraged regionalization without CESBs, set out national guidelines for States and municipalities to access federal funding and introduced a national regulation regime under the National Waters and Basic Sanitation Agency. The model of cooperation that operates in the SUS could serve as a reference for constructing a social pact in the sector. [ABSTRACT FROM AUTHOR]

This paper analysed the effect of freshwater withdrawals and management on agricultural and industrial sectors productivity in the emerging market economies. The auto-regressive distributed lag model and the panel analyses were employed in our estimations. Our result revealed that Brazil had better water use efficiency in agricultural production with annual withdrawals which contribute significantly and positively to the increase in crop and livestock index. In contrast, annual withdrawals for agriculture were considered to be least efficient in Russia, followed by China and India, although, in South Africa, the result suggested an insignificant positive effect in the incremental index. Furthermore, our analysis revealed that freshwater withdrawals have a significant positive impact on industrial outputs in South Africa. Similarly, water withdrawals were positively related to industrial sector productivity in China and Russia. Brazil and India appear to be the least efficient countries where withdrawals impacted negatively (and significantly for Brazil) on industrial sector outputs. Our panel analyses showed that freshwater withdrawals were positively associated with crop and livestock production index and industrial outputs in the BRICS economies. However, the magnitude of the impacts was only significant for the industrial sector. Moreover, investments and private participation in water and sanitation projects impacted significantly and positively in productivity in both sectors. [ABSTRACT FROM AUTHOR]

Irrigation is important for agricultural production and is often decisive for this, especially in arid and semi-arid areas, where precipitation is insufficient. In Brazil, irrigated agriculture is responsible for 46% of withdrawals from water bodies and 67% of the consumption of the total volume of water collected, representing the highest consumptive use in the country. Remote sensing technologies have great potential for developing methods for monitoring irrigated areas. However, mapping irrigated areas is still a challenge, due to the complexity and diversity of irrigation methods and crops, especially in a country with continental dimensions like Brazil. Remote sensing techniques for mapping irrigated areas in Brazil have been applied mainly in areas with center pivot irrigation in the Cerrado, and with paddy rice in the south of Brazil. But few or no applications, involving mapping of crops irrigated by other irrigation methods, mainly in the semi-arid, have been carried out. The objective of this work was to investigate a method for classifying irrigated agriculture in a semiarid region of Brazil, based on the use of Sentinel 2 imagery and random forest algorithm. We proposed a novel and robust methodology showing with preliminary results that it's possible to identify irrigated agriculture in this region with a class-f1-score of 74% for complementary irrigation and 95% for center-pivots. [ABSTRACT FROM AUTHOR]

In Brazil, irrigated agriculture is responsible for 46% of withdrawals of water bodies and 67% of use concerning the total water abstracted volume, representing the most significant consumptive use in the country. Understanding how different crops use water over time is essential for planning and managing water allocation, water rights, and farming production. In this work, we propose a methodology to estimate water used in agriculture irrigated by center pivots in the municipality of Itobi, São Paulo, in the Brazilian Savanna (known as Cerrado), which has strong potential for agricultural and livestock production. The methodology proposed for the water use estimate is based on mapping crops irrigated by center pivots for the 2015/2016 crop year and actual evapotranspiration (ETa). ETa is derived from the Operational Simplified Surface Energy Balance model (SSEBop) and parameterized for edaphoclimatic conditions in Brazil (SSEBop-Br). Three meteorological data sources (INMET, GLDAS, CFSv2) were tested for estimating ETa. The water use was estimated for each meteorological data source, relating the average irrigation balance and the total area for each crop identified in the map. We evaluated the models for each crop present in the center pivots through global accuracy and f1-score metrics, and f1-score was more significant than 0.9 for all crops. The potato was the crop that consumed the most water in irrigation, followed by soy crops, beans, carrots, and onions, considering the three meteorological data sources. The total water volume consumed by center pivots in the municipality of Itobi in the 2015/2016 agricultural year for each meteorological data source was 3.2 million m3 (INMET), 2.5 million m3; (GLDAS), and 1.8 million m3 (CFSv2). [ABSTRACT FROM AUTHOR]

Copyright of Revista Ambiente e Água is the property of Revista Ambiente e Agua and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Agriculture is the economic activity which uses water the most in Brazil, particularly in São Francisco River Basin, where water withdrawals for irrigation granted by water authorities amount to 22.3 billion m3 per year, a number which is close to 81% of the total withdrawal. On the other hand, bulk water in Brazil is underpriced. Water charges for agricultural users neither reflect the economic value of water nor induce a rational and efficient use of water resources, two key concepts of the Brazilian water law. Even so, it is common for irrigators to complain about the water prices charged for their use of bulk water. To throw some light on the real impact of charging water in the agriculture sector, this article evaluates the economic value of irrigation water in the São Francisco River basin through the shadow price approach, calculated by using the Residual Value Method. The analysis was performed for the top ten major São Francisco River basin crops in water use terms, namely corn, soybean, mango, beans, coffee bean, banana, cotton, sugar cane, papaya and rice. Results for the 2019 harvests show that except for sugar cane, all water shadow prices were positive, notably mango, beans and papaya. This paper also evaluated water shadow prices interannual variation from 2014 to 2019 for six crops. Except for sugarcane, the other crops have been profitable most of the time in the last 6 years. A wide fluctuation in the shadow price of water was observed over these years due to variations in sales prices and costs of production. [ABSTRACT FROM AUTHOR]

The quality of the water consumed by a given community is related to its quality of life. In this sense, this study aimed to evaluate, from the perspective of health risk, the physical, chemical, and microbiological quality of drinking water, in a quilombola community, and the qualitative aspects intrinsic to its use and storage. For this, water samples, collected at the exits of the collective water supply system and from eight cisterns that store rainwater, used for human consumption, were analyzed. The samples were subjected to physical, chemical, and microbiological analysis, including adenovirus (HAdV) and enterovirus (EV). The probability of an individual acquiring infection through water consumption was determined by quantitative microbiological risk analysis using HAdV and Escherichia coli (EC) as reference pathogens. The results showed that the water in the deep tubular well had 270.8 mg/L of total hardness, leading to the rejection of its consumption by ingestion. Alternativity, the people in the community consume rainwater stored in cisterns. For this type of water, the presence of heterotrophic bacteria was found in 75%, total coliform was present in 100%, and Enterococci were detected in 25%. Furthermore, EC was present in 25%, EV in 50%, and HAdV in 100% of the samples. The probability of annual infection with HAdV and EC was, in the worst situation, 100% and 1.3%, respectively. Regarding the qualitative and quantitative aspects, there was a significant positive correlation between the absence of EC and the withdrawal of water from the cistern using a pump and the opposite when the withdrawal was carried out using a bucket or hose. Based on the results found, it is important to carry out actions aimed at improving water quality and, consequently, the quality of life of people living in the study community. [ABSTRACT FROM AUTHOR]

Water availability in dry inhabited environments has usually been promoted by large strategic reservoirs, but small non-strategic ones, built by farmers and communities, are unable to cope with long term droughts and inappropriate for human supply. Nevertheless, small reservoirs promote water spatial distribution and play a major role for livelihood in rural areas. To fill the gap of operation methods for non-strategic reservoirs used for irrigation where water is a limiting factor, the NeStRes model was developed. The model is composed of three modules: i) hydrological: to define the reliability of water withdrawals from the reservoir; ii) agricultural: to simulate crop production based on water availability; iii) economic: to compute the possible income from irrigated agricultural crops. NeStRes was applied to 91 reservoirs of the semiarid Banabuiú River Basin – BRB, Brazil. The simulations indicated that the maximum income from the cultivation of maize is obtained when the reservoirs are intensely used, drying completely in one to two thirds of the time. Adoption of a fixed reliability level of daily water supply (54%, in the BRB) generates at least 85% of the maximum possible income for all simulated reservoirs. This model application suggests a paradigm change in the operation of small non-strategic reservoirs in drylands: to use water for crop production and save the revenue, instead of saving water, which is susceptible to evaporation. Although high reliability level is desired for human supply by strategic reservoirs, non-strategic ones can be more intensely explored to generate income from irrigated agriculture in drylands. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ambiente e Água is the property of Revista Ambiente e Agua and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Isoëtes genus comprises a basal lineage of vascular plants with a wide distribution, including aquatic and terrestrial species, which can be attributed to environmental changes throughout its evolutionary history. The underwater quillwort, Isöetes cangae , is endemic to Lake Amendoim in the northern Amazon rainforest region of Brazil. To aid conservation strategies, we investigated the molecular and physiological changes associated with water column reduction and tolerance to terrestrial environments. Remarkably, this aquatic species has demonstrated a tolerance for periods without a water column during ex situ cultivation. Short-term experimental conditions (24 h) revealed upregulation of stress-related genes, while biochemical, morphological, and physiological parameters remained unchanged. In contrast, long-term terrestrial conditions (3–6 months) induced changes in the physiology and morphology of I. cangae , including an increase in antioxidant capacity, photoprotective mechanisms, and the preservation of reproductive structures. The Crassulacean Acid Metabolism was present in both aquatic and terrestrial conditions. Mature and immature spores were able to produce plants even after 12 months of desiccation, with desiccated spores generating more progeny than submerged spores. • Aquatic quillwort I. cangae upregulates stress-related genes after water withdrawal. • I. cangae triggers antioxidant and photoprotective action in terrestrial conditions. • In a long-term terrestrial episode, I. cangae is still able to reproduce. • Dried reproductive structures can survive at least a year. • I. cangae is a crassulacean acid metabolism (CAM) plant. [ABSTRACT FROM AUTHOR]

The semiarid State of Ceará, Brazil, implemented its water management system in the early 1990s. The drought-prone State is densely populated and its supply strongly relies on surface reservoirs, whose yield reduces with silting. Using artificial neural networks and data from 141 monitored dams, we show that the silting ratio of the reservoirs significantly enhanced after the implementation of the water management system. An explanation for this fact is that, since the management started, water withdrawal increased, leading to lower reservoir levels at the beginning of the rainy season. This reduces the probability of spilling, which is the main mechanism of sediment outflow, thus causing excessive siltation. As a result, water availability is expected to reduce by 6% in 30 years, creating a clear contradiction with the management objectives. To tackle this problem, four actions are recommended: to include spilling in the operational rules, to reduce erosion in the basins, to execute sediment reuse policy, and to implement water-demand management. • We investigate the historical siltation of 141 reservoirs a semiarid State of Brazil. • In 1993 a new water management plan (WMP) was implemented in the state. • With ANN, we prove that reservoir siltation rate increased after 1993. • The new WMP reduced spill frequency, increasing sediment trapping in reservoirs. • The new siltation rate is to cause 6% of reduction in water availability in 30 years. [ABSTRACT FROM AUTHOR]

• Oil refineries are energy-intensive, major CO 2 emitters and are usually located in water-stress sites. • Oil refining activity requires large amounts of water, which varies according to the process configuration. • CO 2 mitigation options can reduce water withdrawals, can increase it, or be neutral. Oil refineries are major CO 2 emitters and are usually located in water-stress sites. While some CO 2 mitigation options can reduce water demand, others can increase it, and still others are neutral. By simulating two parametric models, one for all Brazilian refineries, and the other locally detailing the water balance of the country´s largest refinery, this study aimed to quantify the impacts of CO 2 mitigation options on the water use of oil refineries. Findings show that, by pricing CO 2 emissions up to 100 US$/tCO 2 , the list of mitigation options was able to abate 25% of the annual emissions in Brazilian refineries. A relevant share of this abatement derives from the implementation of carbon capture (CC) facilities in fluid catalytic cracking and hydrogen generation units. However, these CC facilities offset the co-benefits of other CO 2 mitigation options that can reduce steam and cold-water requirements in refineries. In fact, for the largest Brazilian oil refinery, the implementation of all mitigation measures had almost no effect on its water balance. This means that CO 2 abatement in refineries has no significant impact on water demand (no negative trade-off). However, this also means that the water stress in oil refineries should be dealt with measures not directly linked to CO 2 abatement (no significant co-benefits). [ABSTRACT FROM AUTHOR]