Water springs: an immeasurable resource for ensuring sustainability.

Water springs are manifestations of groundwater to the surface, forming and ensuring the supply and sustainability of streams, lakes, rivers, and dams. Therefore, its riparian forest is considered an area of permanent preservation, which aims to protect the water, as well as the spring, from consequences of disordered population growth, added to deficient basic sanitation systems, climate change, agricultural activities, inappropriate land uses, unplanned urbanization, and diffuse sources of pollution. In addition to compromising water quality, many of these factors affect the permanence of water upwelling at the source, compromising the formation and continuity of streams, lakes, and rivers. In this context, the objective of the present research was to carry out a bibliographic review on water springs, approaching adjacent themes to the main axis of the study that are fundamental for a deep understanding of their importance for the maintenance of water resources and ensuring biodiversity in the search for the sustainability of life for present and future generations. This research collaborates with the environmental view and shows that the function of a water sources is broader than its concepts can reveal.

Methodology for the assessment of poor-data water resources.

Surface hydrologic modeling becomes a problem when insufficient spatial and temporal information is available. It is common to have useful modeling periods of less than 15 years. The purpose of this work is to develop a methodology that allows the selection of meteorological and hydrometric stations that are suitable for modeling when information is scarce in the area. Based on the scarcity of data, a series of statistical tests are proposed to eliminate stations according to a decision-making process. Although the number of stations decreases drastically, the information used is reliable and of adequate quality, ensuring less uncertainty in the surface simulation models. Individual basin modeling can be carried out considering the poor data. The transfer of parameters can be applied through the nesting of basins to have information distributed over an extensive area. Therefore, temporally and spatially extended modeling can be achieved with information that preserves statistical parameters over time. If data management and validation is performed, the modeled watersheds are well represented; if this is not done, only 26% to 50% of the runoff is represented.

Climate change and land cover effects on water yield in a subtropical watershed spanning the yungas-chaco transition of Argentina.

The demand for mountain water resources is increasing, and their availability is threatened by climate change, emphasizing the urgency for effective protection and management. The upper Sali-Dulce watershed holds vital significance as it contributes the majority of the Sali-Dulce water resources, supporting a densely populated dry region in Northwestern Argentina, covering an area of 24,217 km2. However, the potential impact of climate change and land use/land cover change on water yield in this watershed remains uncertain. This study employs the InVEST Annual Water Yield model to analyze the average water yield in the watershed and evaluate its potential changes under future scenarios of climate and land use/land cover change. InVEST was calibrated using data from multiple river gauges located across the watershed, indicating satisfactory performance (R2 = 0.751, p-value = 0.0054). Precipitation and evapotranspiration were the most important variables explaining water yield in the area, followed by land use. Water yield showed a notable concentration in the montane area with 40% of the watershed accounting for 80% of the water yield, underscoring the importance of conserving natural land cover in this critical zone. Climate change scenarios project an increase in water yield ranging from 21 to 75%, while the effects of land cover change scenarios on water yield vary, with reforestation scenarios leading to reductions of up to 15% and expansions in non-irrigated agriculture resulting in increases of up to 40%. Additionally, water yield distribution may become more concentrated or dispersed, largely dependent on the type of land cover. The combined scenarios highlight the pivotal role of land cover in adapting to climate change. Our findings provide valuable insights for designing future studies and developing policies aimed at implementing effective adaptation strategies to climate change within the Salí-Dulce watershed.

Drought variability assessment using standardized precipitation index, reconnaissance drought index and precipitation deciles across Balochistan, Pakistan / Avaliação da variabilidade da seca usando o índice de precipitação padronizado, índice de seca de reconhecimento e decis de precipitação no Baluchistão, Paquistão

Drought variability analysis is of utmost concern for planning and efficiently managing water resources and food security in any specific area. In the current study, drought spell occurrence has been investigated in the Balochistan province of Pakistan during the past four decades (1981-2020) using standardized precipitation index (SPI), reconnaissance drought index (RDI), and precipitation deciles (PD) at an annual timescale. Precipitation and temperature data collected from 13 synoptic meteorological stations located in Balochistan were used to calculate the SPI, the RDI, and the PD for calculation of drought severity and duration. Based on these indices, temporal analysis shows adverse impacts of drought spells in Nokkundi during 1991-1993, in Barkhan, Dalbandin, Quetta stations during 1999-2000, whereas Barkhan, Dalbandin, Lasbella, Sibi during 2002-2003, Zhob during 2010-2011, Kalat and Khuzdar during 2014-2015, and Panjgur during 2017-2018. Also, the aridity index for each station was calculated based on the UNEP method shows that major part of Balochistan lies in the arid zone, followed by the hyper-arid in the southwestern part and the semi-arid zones in the northeastern part of the province. SPI and RDI results were found more localized than PD, as PD shows extensive events. Furthermore, principal component analysis shows a significant contribution from all the indices. For SPI, RDI, and PD, the first three principal components have more than 70% share, contributing 73.63%, 74.15%, and 72.30% respectively. By integrating drought patterns, long-term planning, and preparedness to mitigate drought impacts are only possible. The RDI was found more suitable and recommended in case of temperature data availability.

A análise da variabilidade da seca é de extrema importância para o planejamento e gestão eficiente dos recursos hídricos e da segurança alimentar em qualquer área específica. No estudo atual, a ocorrência de períodos de seca foi investigada na província do Baluchistão, no Paquistão, durante as últimas quatro décadas (1981-2020), usando índice de precipitação padronizado (SPI), índice de seca de reconhecimento (RDI) e decis de precipitação (PD) em uma escala anual. Dados de precipitação e temperatura coletados de 13 estações meteorológicas sinóticas localizadas no Baluchistão foram usados ​​para calcular o SPI, o RDI e o PD para cálculo da severidade e duração da seca. A análise temporal mostra os impactos adversos dos períodos de seca em Nokkundi durante 1991-1993 e na maior parte da província de 1999 a 2004. Além disso, o índice de aridez para cada estação foi calculado com base no método do PNUMA. Os resultados de SPI e RDI foram encontrados mais localizados do que PD, pois PD apresenta eventos extensos. Além disso, a análise de componentes principais mostra uma contribuição significativa de todos os índices. Para SPI, RDI e PD, os três primeiros componentes principais têm mais de 70% de participação, contribuindo com 73,63%, 74,15% e 72,30%, respectivamente. O planejamento e a preparação de longo prazo para mitigar os impactos da seca só são possíveis por meio da integração dos padrões de seca.

Impacto dos cenários climáticos (2020-2050) na qualidade e disponibilidade de água para abastecimento público na bacia Sorocaba e Médio Tietê / Impact of climatic scenarios (2020-2050) on the quality and availability of water for public supply in the Sorocaba and Middle Tietê basin

Introdução: As mudanças climáticas podem afetar a qualidade e a disponibilidade dos recursos hídricos. Objetivo: Avaliar a tendência das séries temporais de precipitação e vazão e o impacto dos cenários climáticos projetados para o período de 2020-2050 na bacia hidrográfica Sorocaba- Médio Tietê-BHSMT e suas repercussões no abastecimento público de água. Método: Estudo de revisão narrativa sobre os impactos das mudanças climáticas na disponibilidade e qualidade da água. Um estudo de tendência dos dados históricos de precipitação e vazão do período de 1980 a 2020 de quatro estações localizadas na BHSMT, utilizado os métodos de Man-Kendall e de Pettitt. Aplicação do modelo SWAT (Soil Water Assessment Tool) para avaliar o impacto dos cenários climáticos RCP4.5 e RCP8.5 para o período de 2020 a 2050, no ciclo hidrológico da bacia e na disponibilidade de água para abastecimento público. Resultados: Existem muitas lacunas para compreender os impactos dos cenários climáticos nos recursos hídricos e suas repercussões na saúde da população. A análise de tendência dos dados de vazão e precipitação mostrou estacionariedade. A análise dos impactos dos cenários climáticos mostrou importante redução na precipitação e vazão, para ambos os cenários, em especial para o período de 2020-2030 e 2030-2040, oferecendo riscos ao abastecimento de público e segurança hídrica na região. Conclusão: Estratégias envolvendo ampla gama de áreas temáticas e perspectivas para garantir segurança hídrica e ampliar a resiliência das bacias frente aos efeitos das mudanças climáticas são necessárias.

Introduction: Climate change can affect the quality and availability of water resources. Objective: To evaluate the trend of precipitation and flow time series and the impact of climate scenarios projected for the period 2020-2050 in the Sorocaba- Médio Tietê-BHSMT river basin and its repercussions on public water supply. Method: Narrative review study on the impacts of climate change on water availability and quality. A trend study of historical precipitation and flow data from 1980 to 2020 from four stations located in the BHSMT, using the Man-Kendall and Pettitt methods. Application of the SWAT model (Soil Water Assessment Tool) to evaluate the impact of the RCP4.5 and RCP8.5 climate scenarios for the period from 2020 to 2050, on the basin's hydrological cycle and on the availability of water for public supply. Results: There are many gaps in understanding the impacts of climate scenarios on water resources and their repercussions on the population's health. Trend analysis of flow and precipitation data showed stationarity. The analysis of the impacts of the climate scenarios showed an important reduction in precipitation and flow, for both scenarios, especially for the period 2020-2030 and 2030-2040, posing risks to public supply and water security in the region. Conclusion: Strategies involving a wide range of thematic areas and perspectives to ensure water security and increase the resilience of basins to the effects of climate change are necessary.

Application of spatial environmental indicators in the assessment of degradation potential of water resources in water basins.

Changes in land use have been occurring in a continuous and disorderly way in recent decades due to rapid population growth and the growing demand for food. These constant changes result in a series of harmful effects to the environment, especially to water resources, significantly changing their availability and quality. This study aims to evaluate the degradation potential of watersheds through an evaluation of some environmental indicators using arithmetic means to construct an index called in this research "index of potential environmental degradation" (IPED). To form the IPED, the hydrographic sub-basins of the Sorocabuçu River, located in the central west of the State of São Paulo, Brazil, comprised the study area. The results showed that most hydrographic sub-basins, that is, eight units, present degradation values ranging from moderate to very high, resulting mainly from low conservation values of forests plus a use destined to the planting of temporary cultures depending on good physical conditions. On the other hand, only one sub-basin showed a low degradation value. The methodology used for the development of the IPED is easy to apply and an effective tool for environmental analyses. It may contribute to studies and forms of planning and land use management aiming the conservation of water resources and protected areas and reduction of degradation.

Frontiers in páramo water resources research: A multidisciplinary assessment.

Interdisciplinary knowledge is necessary to achieve sustainable management of natural resources. However, research is still often developed in an exclusively disciplinary manner, hampering the capacity to holistically address environmental issues. This study focuses on páramo, a group of high-elevation ecosystems situated around ∼3000 to ∼5000 m a.s.l. in the Andes from western Venezuela and northern Colombia through Ecuador down to northern Peru, and in the highlands of Panama and Costa Rica in Central America. Páramo is a social-ecological system that has been inhabited and shaped by human activity since ∼10,000 years BP. This system is highly valued for the water-related ecosystem services provided to millions of people because it forms the headwaters of major rivers in the Andean-Amazon region, including the Amazon River. We present a multidisciplinary assessment of peer-reviewed research on the abiotic (physical and chemical), biotic (ecological and ecophysiological), and social-political aspects and elements of páramo water resources. A total of 147 publications were evaluated through a systematic literature review process. We found that thematically 58, 19, and 23 % of the analyzed studies are related to the abiotic, biotic, and social-political aspects of páramo water resources, respectively. Geographically, most publications were developed in Ecuador (71 % of the synthesized publications). From 2010 onwards, the understanding of hydrological processes including precipitation and fog dynamics, evapotranspiration, soil water transport, and runoff generation improved, particularly for the humid páramo of southern Ecuador. Investigations on the chemical quality of water generated by páramo are rare, providing little empirical support to the widespread belief that páramo environments generate water of high quality. Most ecological studies examined the coupling between páramo terrestrial and aquatic environments, but few directly assessed in-stream metabolic and nutrient cycling processes. Studies focused on the connection between ecophysiological and ecohydrological processes influencing páramo water balance are still scarce and mainly related to the dominant vegetation in the Andean páramo, i.e., tussock grass (pajonal). Social-political studies addressed páramo governance and the implementation and significance of water funds and payment for hydrological services. Studies directly addressing water use, access, and governance in páramo communities remain limited. Importantly, we found only a few interdisciplinary studies combining methodologies from at least two disciplines of different nature despite their value in supporting decision-making. We expect this multidisciplinary synthesis to become a milestone to foster interdisciplinary and transdisciplinary dialogue among individuals and entities involved in and committed to the sustainable management of páramo natural resources. Finally, we also highlight key frontiers in páramo water resources research, which in our view need to be addressed in the coming years/decades to achieve this goal.

Estimations of future reservoir volumes under different climate scenarios for a tropical reservoir in a small Caribbean Island, Trinidad.

Freshwater resources supply has always presented challenges and considering a changing climate quantifying the available water in the future is important. In the Caribbean, based on projections it is likely that the island of Trinidad would receive less intense rainfall, experience more dry days, become drier and warmer, and the water resources be decreased. In this study, the impact of a changing climate on the Navet Reservoir in Trinidad was investigated and reservoir volumes were quantified for the period 2011-2099. This period was subdivided into three time periods, 2011-2040, 2041-2070, and 2071-2099, and evaluated under the representative concentration pathways (RCPs): RCPs 2.6, 4.5, 6.0, and 8.5. Utilizing a calibrated/validated Soil Water Assessment Tool (SWAT) model for the Navet Reservoir together with projections from five general circulation models (GCMs), future monthly and seasonal reservoir volumes were estimated. The GCM precipitation and temperature data were bias-corrected using linear scaling and variance scaling methods. It was found that reservoir volumes are likely to be the lowest during the period 2041-2070 at the Navet Reservoir. Additionally, the projected reservoir volumes are reliable, resilient, and not vulnerable. These results may be used by water managers in the adaptation and mitigation of the impacts of a changing climate, thus, building resilience in the water sector.

Deterministic and probabilistic modeling of microbiological quality using the QUAL-UFMG: a water resource management tool applied on the slope waters of the Grande River, Brazil.

The present work presents a methodology for modeling the quality of surface water, aiming at the management of hydrographic basins and the best allocation of resources in the treatment of sanitary sewage, considering the predominant uses of water and microbiological quality. The QUAL-UFMG model was used, composed of Excel spreadsheets, where visual basic for applications (VBA) routines were implemented, enabling deterministic and probabilistic modeling through Monte Carlo simulations. The proposed methodology was applied to a Brazilian hydrographic basin, called the GD2 Planning Unit (Grande River Slopes), considering the discharges of sanitary sewage from 30 municipal seats and approximately 740,000 inhabitants. Four scenarios were studied: the current situation (C-01), the trend for the year 2033 (C-02), compliance with environmental legislation (C-03) and compliance with the main uses of the basin (C-04). The results showed that for C-01 and C-02, the water quality, in terms of thermotolerant coliforms, in most stretches does not meet the defined uses. Even complying with the provisions of environmental legislation (C-03), which do not provide for disinfection, only the largest watercourses would have adequate quality for use. Complete service would only be achieved in C-04, which provides for universal sewage treatment with disinfection for the vast majority of municipalities.

Development of water quality index as a tool for urban water resources management.

Urban stream monitoring programs rarely consider the daily cycle of water quality. Furthermore, water quality indexes (WQIs) often rely on an excessive number of correlated parameters. To the best of our knowledge, no previous study used both the principal component analysis (PCA) and the daily cycle of the water quality of urban streams to create better WQIs. In this context, the present study aimed to develop a novel urban WQI (WQIurban) considering these two factors. Moreover, the main WQI in Brazil for water quality assessment for public supply (WQIcetesb) was used as a starting point (parameters: total solids (TS), temperature, turbidity, biochemical oxygen demand, pH, dissolved oxygen (DO), total nitrogen, total phosphorus, and thermotolerant coliforms (Escherichia coli)). The selected parameters to integrate the WQIurban received weights according to their importance for the conformation of water quality and a quality value was assigned to each parameter as a function of its concentration or measure. The developed WQIurban (parameters: pH, TS, E. coli, and DO) was able to maintain the seasonal and daily patterns of the urban stream water quality compared to the WQIcetesb. Nevertheless, the spatial relationship among the sampling sites was somewhat lacking. Our findings can help environmental managers, policy planners, and local researchers to improve their urban stream monitoring programs, saving money, time, and resources. Moreover, the WQIurban can be helpful during exceptional circumstances in which the water quality of urban streams must be quickly assessed.

Water parameters correlated with the zootechnical performance of shrimp Litopenaeus vannamei grown in oligohaline waters

The present study aimed to correlate the influence of water quality, cultivation time, area, and density of ponds on the zootechnical performance of shrimp Litopenaeus vannameiin oligohaline waters. It was demonstrated that, under the conditions of this research, better control of temperature, pH and water alkalinity can be employed. Ammonia levels were within the normal range and correlated positively with the growth rate (ρ= 0.69859) and production (ρ= 0.66362) of the ponds. There was also a positive correlation between cultivation time and pond density with shrimp weight (ρ= 0.75305 and 0.68933) and pond productivity (ρ= 0.74763 and 0.79367, respectively). Negative correlations were observed between: I) pH with shrimp survival (ρ= -0.73238) and pondproduction (ρ= -0.68696); II) alkalinity and pond production (ρ= -0.66162). The results show that the cultivation of shrimp L.vannameiin oligohaline waters is viable and there is potential for increased productivity associated with better hydrologicalmonitoring and use of higher density and cultivation time by some producers.(AU)

Irrigation management of common bean cultivars with contrasting growth habits

A study was undertaken comparing the water requirements of two common bean ( Phaseolus vulgaris L.) cultivars to generate specific recommendations aimed at optimizing water use. To accomplish this work, the agronomic performance, responsiveness to water and water productivity of these two common bean cultivars of determinate and indeterminate growth habits were identified. The 2-year experiment was carried out during the winter growing season in the southeast of Brazil. Cultivars IAC Imperador, with an early season of determinate growth habit, and IPR Campos Gerais, having a mid-season of indeterminate growth habit, were subjected to five irrigation levels (54, 70, 77, 100, and 132 % of the crop evapotranspiration). Water deficit affected agronomic performance, reducing plant height (by up to 29 %), leaf area index (by up to 40 %), soil cover fraction (by up to 28 %), and grain yield (GY - by up to 31 %), in both cultivars. In contrast, excess water was more detrimental to cultivar IAC Imperador. Cultivar IPR Campos Gerais produced 18 % more than GY, showing superior water productivity and response to irrigation depth than IAC Imperador. Out of all the variables evaluated, the soil cover fraction correlated the most with grain yield in both common bean cultivars during the 2-year study. In other words, cover fraction evaluation in common bean allows for estimating crop production potential, which helps producers and technicians in their decision making regarding management practices. Thus, a cultivar directly affects water use in common bean production, thereby suggesting the need for a or water conservation strategy and sustainability of irrigated common bean production.(AU)

Low fertilization optimizes the water use efficiency of an Amazonian canga grass for mineland rehabilitation / Baixa fertilização otimiza a eficiência do uso da água de uma gramínea nativa da canga amazônica para reabilitação de minas

The peculiar characteristics of mining waste substrates represent a significant challenge for environmental rehabilitation. Here, we evaluated the revegetation potential of Paspalum cinerascens on substrates from mining areas of Serra dos Carajás, a region harboring a large mine complex in the eastern Brazilian Amazon. Paspalum cinerascens is a native grass widely distributed in the canga ecosystem, a vegetation type covering iron ore reserves. Seeds of P. cinerascens harvested in canga were germinated in sterilized quartzite sand and the seedlings grown in controlled conditions for 90 days. The seedlings were then cultivated in canga topsoil (control, without fertilization) and mining waste substrate with half and complete fertilization currently applied at the beginning of mineland rehabilitation in Serra dos Carajás. Regardless of fertilization, plants grown in the mining waste substrate did not differ in carbon assimilation, tillering rate and root biomass, despite higher leaf nutrient content and lower root: shoot ratio when compared to plants in canga topsoil. Compared to the control, complete fertilization led to significantly taller plants, higher shoot biomass and reduced water use efficiency. Half fertilization led to higher phosphorus and water use efficiency and stomatal density. Our results confirmed that P. cinerascens has adaptive traits to grow and thrive in the harsh environmental conditions of post iron ore mining, and can be used in rehabilitation processes. Moreover, half fertilization led to plants with optimized water loss in exchange for carbon without significant costs to plant growth, an interesting trait for rehabilitation in areas experiencing water restrictions.(AU)

As características peculiares dos substratos de remanescentes da mineração (estéril de mina) representam um desafio para a recuperação ambiental. Neste estudo avaliamos o potencial de uso de Paspalum cinerascens para revegetação de estéril de mina na Serra dos Carajás, Pará (Brasil). Paspalum cinerascens é uma gramínea nativa amplamente distribuída nas cangas, vegetação típica dos campos rupestres que cobrem reservas de minério de ferro. As plantas de P. cinerascens foram cultivadas em topsoil de canga (controle) e em estéril de mina com meio e completo regime de fertilização atualmente empregado para revegetação das áreas mineradas na Serra dos Carajás. Foram utilizadas sementes coletadas nas cangas e as plantas foram cultivadas em condições controladas por 90 dias. Independentemente da fertilização, plantas cultivadas em estéril de mina não apresentaram diferenças significativas na assimilação de carbono, perfilhamento ou biomassa radicular, apesar de valores mais elevados de nutrientes foliares e menor razão raiz: parte aérea quando comparadas às plantas em topsoil de canga. A fertilização completa resultou em plantas mais altas, maior biomassa aérea e menor eficiência no uso da água. Metade da fertilização aumentou a densidade estomática, a eficiência de uso da água e de fósforo. Esses resultados confirmaram que P. cinerascens possui características adaptativas para crescer e prosperar em condições ambientais adversas remanescentes da mineração, sendo indicada para uso em processos de recuperação de áreas degradadas na Serra dos Carajás. Além disso, o uso de metade do regime de fertilização otimiza o uso da água pelas plantas sem perdas significativas de crescimento, uma característica desejável para recuperação de áreas com restrições hídricas.(AU)

Improvement of reference crop evapotranspiration estimates using limited data for the Brazilian Cerrado

Evapotranspiration (ET) is a key component of the hydrological cycle. Therefore, adequately estimating it is crucial to improving water resource planning and management.One of the most affordable methods of estimating ET is first to estimate reference crop evapotranspiration (ETo) and later associate it to crop and soil coefficients. The FAO Kc-ETo approach can be used only when ETo is computed with the FAO Penman-Monteith equation. However, low data availability may restict the equations used to estimate ETo. In this study, we assess and calibrate common methods used to estimate ETo under such conditions of limited data availability. Based on the annual calibration, the Makkink (NSE = 0.85) outperformed the Priestley-Taylor (NSE = 0.73), Hargreaves-Samani (NSE = 0.56), and Penman-Monteith temperature approach (NSE = 0.58). The seasonal calibration of parameters showed no significant improvement to the methods assessed (ΔNSE ≤ 0.01), except for the Priestley-Taylor (ΔNSE = 0.06). The performance of temperature-based equations was particularly limited due to the performance of the equation adopted to estimate global solar radiation. Thus, improving the representation of global solar radiation for limited data availability can also play a key role in improving ETo prediction.(AU)

Análise dos critérios de priorização dos investimentos do FEHIDRO no período de 1995 a 2019 / Analysis of FEHIDRO's investment prioritization criteria from 1995 to 2019, 2023

Em 1989 foi instituído no estado de São Paulo o sistema integrado de gerenciamento de recursos hídricos, de forma a reunir órgãos municipais, estaduais e sociedade civil e assegurar os meios financeiros e institucionais para finalidades específicas, como a utilização racional dos recursos hídricos, superficiais e subterrâneos, assegurando o uso prioritário para o abastecimento das populações. A lei foi elaborada de forma garantir a gestão descentralizada, participativa e integrada dos recursos hídricos em relação às particularidades de cada Bacia Hidrográfica. O FEHIDRO - Fundo Estadual de Recursos Hídricos tem como objetivo dar suporte a política de recursos hídricos promulgada por meio do financiamento de programas e ações na área, de modo a promover a melhoria e a proteção de corpos d´água e de suas Bacias Hidrográficas. O fundo investiu no período de 1995 a 2019 R$ 916.955.735,79 em 5.886 empreendimentos concluídos (SInFEHIDRO). O aumento da captação do fundo associado ao papel da água como recurso natural essencial à vida, ao desenvolvimento econômico e ao bem-estar social reforça a criticidade e a importância da melhoria contínua da gestão dos recursos hídricos. O objetivo desse trabalho é analisar os investimentos realizados e apresentar um diagnóstico com proposta de indicadores e subsídios para priorização de projetos a serem contemplados pelo fundo, visando atender a indicadores tidos como prioritários para a universalização da água potável e melhor índice de qualidade dos mananciais. Essa análise será fundamentada com o método de revisão bibliográfica e levantamento de dados dos empreendimentos disponibilizados pelo Sistema Integrado de Recursos Hídricos (SIGRH).

In 1989, the state of São Paulo established an integrated water resources management system, in order to gather municipal, state and civil society bodies and to ensure financial and institutional means for specific purposes, such as the rational use of water resources, surface and underground, ensuring priority use to supply the population. The law was designed to ensure decentralized, participatory and integrated management of water resources in relation to the particularities of each Hydrographic Basin. FEHIDRO - State Water Resources Fund aims to support the water resources policy enacted by financing programs and actions in the area, in order to promote the improvement and protection of water bodies and their hydrographic basins. From 1995 to 2019, the fund invested R$ 916.955.735,79 in 5,886 completed projects (SInFEHIDRO). The increase in funding from the fund associated with the role of water as a natural resource essential to life, economic development and social well-being reinforces the criticality and importance of continuous improvement in the management of water resources. The objective of this work is to analyze the investments made and present a diagnosis with a proposal of indicators and subsidies for prioritizing projects to be contemplated by the fund, aiming to meet the indicators considered as priorities for the universalization of drinking water and a better index of quality of springs. This analysis will be based on the method of bibliographic review and survey of data from the projects made available by the Integrated Water Resources System (SIGRH).

Nutrient dynamics in water resources of productive flatland territories in the Pampean region of Argentina: evaluation at a watershed scale.

The Pampean plains in South America are well-known for their livestock and agricultural productivity. The peri-urban watershed of El Pescado Creek (Central-Eastern Argentina) has been significantly modified in the last few years due to local land-use changes. This work aims to analyze the dynamics of nutrient content associated with the surface water-groundwater relationship in this watershed and to define the trophic state of the watercourse. Sampling sites were selected for both surface water and groundwater analyses, and field surveys were carried out during the spring and summer of 2017. Handmade shallow groundwater wells were installed along the floodplain of the watercourse. Deep groundwater was analyzed in agricultural and livestock farms. In situ determinations included dissolved oxygen (DO), pH, electrical conductivity (EC), turbidity, transparency, and temperature measurements. Laboratory analyses included NO3--N, total nitrogen (TN), soluble reactive phosphorus (SRP), total phosphorus (TP), and phytobenthonic and phytoplanktonic chlorophyll-a. Results showed an increase in EC and nutrient concentration in the summer samples (both in surface water and shallow groundwater), along with higher turbidity of the surface water. Water flow was dissimilar between samplings (spring: 1.735 m3/s, summer: 0.065 m3/s), showing contrasting hydrological scenarios. Low wash-out conditions enhanced phytobenthonic algae biomass growth, turning most of the sites towards a eutrophic state in summer. Our results showed that the dynamics of nitrogen and phosphorus compounds in the watershed of El Pescado Creek depend on the hydrodynamic processes of the watershed, the different land-uses, and the chemical characteristics of these compounds. In order to develop sustainable management strategies, further understanding of nutrient concentrations effects, and the factors affecting them, must be done in this area of the Pampean region.

Erosion susceptibility mapping in the Central-Eastern Region of São Paulo in the last few decades.

Soil degradation has become a critical global environmental challenge as a result of rapid population growth, intensified erosion, and increased global warming. Depletion of nutrients, decreased infiltration, availability of water in the subsoil, silting, and eutrophication of surface water resources are directly associated with soil degradation. Water erosion is one of the primary causes of erosion. The principal objective of this study was to understand how climate change and land use have affected susceptibility to erosion in the central-eastern region of the state of São Paulo, Brazil, over the past few decades. Using the technique of multicriteria decision analysis and comparison of thematic layers in pairs, different factors that contribute to soil erosion were integrated in a GIS environment to map erosion hotspots. The results indicated increasing very high, high, and medium erosion susceptibility class percentage. Slope and soil types were the most sensitive factors; however, changes in land use, in particular, increased land cultivation and expanded areas highly susceptible to erosion in late 2019. The results of this study will assist in implementing soil conservation practices in such areas, reducing soil degradation, and increasing productivity.

Modeling the effect of climate change scenarios on water quality for tropical reservoirs.

Impact of natural phenomena and anthropogenic activities on water quality is closely related with temperature increase and global warming. In this study, the effects of climate change scenarios on water quality forecasts were assessed through correlations, prediction algorithms, and water quality index (WQI) for tropical reservoirs. The expected trends for different water quality parameters were estimated for the 2030-2100 period in association with temperature trends to estimate water quality using historical data from a dam in Mexico. The WQI scenarios were obtained using algorithms supported by global models of representative concentration pathways (RCPs) adopted by the Intergovernmental Panel on Climate Change (IPCC). The RPCs were used to estimate water and air temperature values and extrapolate future WQI values for the water reservoir. The proposed algorithms were validated using historical information collected from 2012 to 2019 and four temperature variation intervals from 3.2 to 5.4 °C (worst forecast) to 0.9-2.3 °C (best forecast) were used for each trajectory using 0.1 °C increases to obtain the trend for each WQI parameter. Variations in the concentration (±30, ±70, and +100) of parameters related to anthropogenic activity (e.g., total suspended solids, fecal coliforms, and chemical oxygen demand) were simulated to obtain water quality scenarios for future health diagnosis of the reservoir. The results projected in the RCP models showed increasing WQI variation for lower temperature values (best forecast WQI = 74; worst forecast WQI = 71). This study offers a novel approach that integrates multiparametric statistical and WQI to help decision making on sustainable water resources management for tropical reservoirs impacted by climate change.

Drought variability assessment using standardized precipitation index, reconnaissance drought index and precipitation deciles across Balochistan, Pakistan.

Drought variability analysis is of utmost concern for planning and efficiently managing water resources and food security in any specific area. In the current study, drought spell occurrence has been investigated in the Balochistan province of Pakistan during the past four decades (1981-2020) using standardized precipitation index (SPI), reconnaissance drought index (RDI), and precipitation deciles (PD) at an annual timescale. Precipitation and temperature data collected from 13 synoptic meteorological stations located in Balochistan were used to calculate the SPI, the RDI, and the PD for calculation of drought severity and duration. Based on these indices, temporal analysis shows adverse impacts of drought spells in Nokkundi during 1991-1993, in Barkhan, Dalbandin, Quetta stations during 1999-2000, whereas Barkhan, Dalbandin, Lasbella, Sibi during 2002-2003, Zhob during 2010-2011, Kalat and Khuzdar during 2014-2015, and Panjgur during 2017-2018. Also, the aridity index for each station was calculated based on the UNEP method shows that major part of Balochistan lies in the arid zone, followed by the hyper-arid in the southwestern part and the semi-arid zones in the northeastern part of the province. SPI and RDI results were found more localized than PD, as PD shows extensive events. Furthermore, principal component analysis shows a significant contribution from all the indices. For SPI, RDI, and PD, the first three principal components have more than 70% share, contributing 73.63%, 74.15%, and 72.30% respectively. By integrating drought patterns, long-term planning, and preparedness to mitigate drought impacts are only possible. The RDI was found more suitable and recommended in case of temperature data availability.

Efficient removal of antibiotics from water resources is a public health priority: a critical assessment of the efficacy of some remediation strategies for antibiotics in water.

This review discusses the fundamental principles and mechanism of antibiotic removal from water of some commonly applied treatment techniques including chlorination, ozonation, UV-irradiation, Fenton processes, photocatalysis, electrochemical-oxidation, plasma, biochar, anaerobicdigestion, activated carbon and nanomaterials. Some experimental shortfalls identified by researchers such as certain characteristics of degradation agent applied and the strategies explored to override the identified limitations are briefly discussed. Depending on interactions of a range of factors including the type of antibiotic compound, operational parameters applied such as pH, temperature and treatment time, among other factors, all reviewed techniques can eliminate or reduce the levels of antibiotic compounds in water to varying extents. Some of the reviewed techniques such as anaerobic digestion generally require longer treatment times (up to 360, 193 and 170 days, according to some studies), while others such as photocatalysis achieved degradation within short contact time (within a minimum of 30, but up to 60, 240, 300 and 1880 minutes, in some cases). For some treatment techniques such as ozonation and Fenton, it is apparent that subjecting compounds to longer treatment times may improve elimination efficiency, whereas for some other techniques such as nanotechnology, application of longer treatment time generally meant comparatively minimal elimination efficiency. Based on the findings of experimental studies summarized, it is apparent that operational parameters such as pH and treatment time, while critical, do not exert sole or primary influence on the elimination percentage(s) achieved. Elimination efficiency achieved rather seems to be due more to the force of a combination of several factors.