Suchergebnisse

To minimize and counter decline of groundwater levels and improve the availability of water for cropproduction, Managed Aquifer Recharge (MAR) interventions are widely adopted across India, often ini-tiated or supported by, local communities, state and central governments to improve the availability ofwater for irrigation. While the literature on MAR in India is vast, the science of their construction is lack-ing. Furthermore, there is an absence of a structured approach to evaluate the performance and impactof MAR interventions. Often, performance and impacts of MAR have been commented upon together,without distinguishing the two.In this article, we aim to propose that performance and impact are different from each other, andthat the evaluation of MAR interventions should take into account such differences between them. Aframework for performance and impact analysis, based on three levels, viz. primary, secondary and ter-tiary, is outlined. It is then applied to seven selected MAR interventions in India, Adarsha watershed –Andhra Pradesh, Gokulpura-Goverdhanpura watershed – Rajasthan, Kodangipalayam watershed – TamilNadu, Chikalgaon watershed – Maharashtra, Rajasamadhiyala watershed – Gujarat, Satlasana watershed– Gujarat and Sujalam Sufalam Yojana – Gujarat. Although, the evaluations of these case studies reportedwere not categorized into performance and impact, most of them have addressed both. However, noneof them could explicitly demonstrate that reported impacts were uniquely related to MAR interventions.If impacts are used as a surrogate for performance, it must be shown that impacts are uniquely linked toMAR interventions.

This paper deals with the physico-chemical properties of ethanol and ethanol-water solutions. The data of ethanol properties and its water solutions, which were obtained from literature, are presented in the form of Equations and Tables.Extended properties include data for pure ethanol (density, vapor pressure, surface tension, viscosity, molar and specific heat capacity, enthalpy of evaporation, thermal conductivity and static relative permittivity) and tabled data for ethanol-water solutions (0–100% ethanol) as well: concentrative properties, surface tension and thermal conductivity at20 °C, density, viscosity, boiling point and equilibrium liquid-vapor at normal pressure.

World, nowadays, encounters serious water scarcity problem. During the past few years, by advent of Smart Energy and Water Meter (SEWM) and its installation at the electro-pumps of the water wells, one had believed that it could be the golden key to address the groundwater resources over-pumping issue. In fact, implementation of these Smart Meters managed to control the water table drawdown for short; but it was not a sustainable approach. SEWM has been considered as law enforcement facility at first; however, for solving a complex socioeconomic problem like shared groundwater resources management, more than just enforcement is required: participation to conserve common resources. The well owners or farmers, as water consumers, are the main and direct stakeholders of this system and other stakeholders could be government sectors, investors, technology providers, privet sectors or ordinary people. Designing a socio-technical system not only defines the role of each stakeholder but also can lubricate the communication to reach the system goals while benefits of each are considered and provided. Farmers, as the key participators for solving groundwater problem, do not trust governments but they would trust a fair system in which responsibilities, privileges and benefits are clear. Technology could help this system remained impartial and productive. Social aspects provide rules, regulations, social objects and etc. for the system and help it to be more human-centered. As the design methodology, Design Thinking provides probable solutions for the challenging problems and ongoing conflicts; it could enlighten the way in which the final system could be designed. Using Human Centered Design approach of IDEO helps to keep farmers in the center of the solution and provides a vision by which stakeholders' requirements and needs are addressed effectively. Farmers would be considered to trust the system and participate in their groundwater resources management if they find the rules and tools of the system fair and ...

Abstract. Compound floods are an active area of research in which the complex interaction between pluvial, fluvial, coastal and groundwater flooding are analyzed. A number of studies have simulated the compound flooding impacts of precipitation, river discharge and storm surge variables with different numerical models and linking techniques. However, groundwater flooding is often neglected in flood risk assessments due to its sporadic frequency (as most regions have water tables sufficiently low that do not
exacerbate flooding conditions), isolated impacts and considerably lower
severity with respect to other types of flooding. This paper presents a
physics-based, loosely coupled modeling framework using FLO-2D and
MODFLOW-2005 that is capable of simulating surface–subsurface water
interactions. FLO-2D, responsible for the surface hydrology and infiltration processes, transfers the infiltration volume as recharge to MODFLOW-2005 until the soil absorption capacity is exceeded, while MODFLOW-2005 returns exchange flow to the surface when the groundwater heads are higher than the surface depth. Three events characterized by short-duration intense precipitation, average tide levels and unusually high water table levels are used to assess the relevance of groundwater flooding in the Arch Creek Basin, a locality in North Miami particularly prone to flooding conditions. Due to limitations in water level observations, the model was calibrated based on properties that have experienced repetitive flooding losses and validated using image-based volunteer geographic information (VGI). Results suggest that groundwater-induced flooding is localized, and high groundwater heads influence pluvial flooding as the shallow water table undermines the soil infiltration capacity. Understanding groundwater flood risk is of particular interest to low-elevation coastal karst environments as the
sudden emergence of the water table at ground surface can result in social
disruption, adverse effects to essential services and damage to infrastructure. Further research should assess the exacerbated impacts of
high tides and sea level rise on water tables under current and future
climate projections.

This is a conference paper. ; The state of Maharashtra in India, covers an area of 307,713 sq. km. and supports a population of over 82 million people. Over half of this population is rural. The government of Maharashtra has identified 20,000 villages, which face problems related to water. In these villages conventional sources like open dugwells, borewells and piped water supplies fail due to depleting water tables, poor water quality or the high costs involved in operation and maintenance. Many of these villages are supplied by water tankers, especially during the dry pre-monsoon. Water supplied by tankers is prone to pollution, as well as extremely expensive.

Tesis para obtener el grado de Magister Scientiae en Manejo y Conservación de Recursos Naturales para la Agricultura, orientación Agroecosistemas, de la Universidad Nacional de Mar del Plata, en agosto 2020. ; Las inundaciones constituyen procesos esenciales tal como lo son el flujo de energía y el ciclo de nutrientes, fundamentales en el mantenimiento de humedales y ecosistemas costeros. Sin embargo, cuando nos referimos a agroecosistemas, estas perturbaciones naturales causan efectos apreciables tanto sobre las comunidades vegetales y animales, como sobre los asentamientos urbano rurales presentes en la región, afectando la economía, el transporte y la infraestructura local asociada a los mismos. Particularmente en el caso del NE de La Pampa, durante los años 1999 y 2001, se registraron precipitaciones extraordinarias, que dieron lugar a situaciones de inundación y anegamiento severos afectando una importante superficie productiva. Otra situación similar ocurrió durante el otoño del año 2017. En este contexto de dinamismo constante del paisaje pampeano, las imágenes satelitales acopladas a un entorno SIG, proporcionan una herramienta adecuada para el estudio de la evolución de las áreas anegadas. Esta información sumada a otras capas permitiría desarrollar sistemas de prevención, seguimiento y evaluación a diferentes escalas espaciales y temporales. En la presente tesis se evaluó a través del análisis de imágenes satelitales, la dinámica de las inundaciones en las cuencas del departamento Maracó durante un período de 25 años, comprendido entre 1993-2017. Para completar el estudio se evaluaron registros de precipitaciones, niveles freáticos, excesos hídricos y uso de la tierra (uso consuntivo). Si bien la máxima superficie inundada ocurrió en la primavera del año 2001 para ambas cuencas, en la cuenca con tosca ("Oeste") la superficie inundada en términos relativos fue superior en casi todo el período, situación muy evidente en el período de inundación 1999-2002 (excepto en la inundación 2016-2017 donde la cuenca "Este" resulta ser más afectada). Al menos dos son los factores que pueden explicar la diferencia de permanencia del agua en la superficie del suelo, entre las cuencas "Este" y "Oeste": 1) la diferencia textural y, 2) la profundidad de la tosca. El análisis de correlación entre la lluvia caída 15, 30, 60 y 90 días antes de la fecha de la imagen satelital y la superficie inundada, presento mejor ajuste con la lluvia acumulada de 60 días, explicando un poco más del 50% de la ocurrencia de las inundaciones. Los datos de uso de la tierra indicaron una clara tendencia de aumento de la superficie destinada a cultivos, acompañada de una disminución de la superficie destinada a pasturas para ambas cuencas. Esto se ve reflejado en una disminución del uso consuntivo anual que realiza la vegetación. Es decir, el cambio en el uso de la tierra en los últimos años hacia especies que evapotranspiran menor cantidad de agua (dejando, por lo tanto, un volumen mayor disponible en el perfil del suelo), facilitan la posterior ocurrencia de inundaciones cuando se manifiestan las precipitaciones. Sin embargo, estos cambios fueron acompañados por una profundización de los niveles freáticos a través del tiempo, situación contraria a lo esperado ; Floods are essential processes such as energy flow and nutrient cycle, fundamental in the maintenance of wetlands and coastal ecosystems. However, when we refer to agroecosystems, these natural disturbances cause appreciable effects both on plant and animal communities, and on urban-rural settlements in the region, affecting the economy, transport and local infrastructure associated with them. Particularly in the case of the NE of La Pampa, during the years 1999 and 2001, extraordinary rainfalls were recorded, causing severe flooding and waterlogging situations, affecting an important productive area. Another similar situation occurred during the autumn of 2017. In this context of constant dynamism of the Pampean landscape, satellite images coupled with a GIS environment provide an adequate tool for studying the evolution of flooded areas. This information, added to other layers, would allow the development of prevention, monitoring and evaluation systems at different spatial and temporal scales. In this thesis the dynamics of floods in the basins of Maracó political district during a 25-year period (1993-2017), were evaluated through the analysis of satellite images. To complete the study, rainfall records, groundwater levels, water excesses and land use (consumptive use) were evaluated. Although the maximum flooded area occurred in the spring of 2001 for both basins, in the basin with rough ("West") the flooded area in relative terms was higher in almost the entire period, situation more evident in the 1999-2002 flood period (except in the 2016-2017 flood where the "East" basin was more affected). At least two are the factors that can explain the difference in the permanence of water on the soil surface, between the "East" and "West" basins: 1) the textural difference and, 2) the depth of the rough. The correlation analysis between the fallen rain 15, 30, 60 and 90 days before the satellite image date and the flooded surface, presented a better adjustment with the accumulated rain of 60 days, explaining a little more than 50% of the occurrence of the floods. The land use data indicated a clear trend of increase in the area devoted to crops, accompanied by a decrease in the area devoted to pastures for both basins. This is reflected in a decrease in annual consumptive use by vegetation. That is, the change in land use in the recent years towards species that evapotranspire less amount of water (leaving a greater volume available in the soil profile), facilitate the subsequent occurrence of floods when excesive rainfall occurs. However, these changes were accompanied by a deepening of the water tables over time, a situation contrary to what was expected. ; EEA Anguil ; Fil: Carreño, Lorena Veronica. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Anguil; Argentina

During the expansion of urban areas, small natural reserves have often been left intact within the built environment as central elements of biodiversity conservation, ecological connectivity, landscape sustainability, and quality of life of urban dwellers. Consequently, the surrounding urbanized landscape may impact the environmental conditions of these reserves (e.g., high temperatures, low moisture conditions), resulting in the need for extensive maintenance. This study presents an estimation of the water balance over two years (2017–2018) in three small urban reserves (between 2 and 30 ha) within the Greater Melbourne metropolitan area in Australia, for the purpose of understanding tree water use. Measurements of micrometeorological variables, soil moisture content profiles, water-table levels, sap flow velocities, and stem diameter variations were used to quantify the water sources of tree transpiration in these reserves. Results revealed that, despite the urban surroundings and the climate variations, these reserves have enough water to sustain tree transpiration. In two of the three reserves, groundwater was pivotal in sustaining transpiration rates; specifically, groundwater was estimated to contribute about 30–40% of the total transpiration amount during the driest periods of the year. Groundwater also played an essential role during nights with temperatures above 25 °C, helping trees to maintain night-time water use from 3 to 16% of the daily water use. In the third reserve, the presence of a shallow layer of heavy clay supplied water to the trees, which were able to maintain relatively constant transpiration rates throughout the year. These results demonstrate the importance of understanding the water regime of each urban reserve in order to support government authorities in preserving these ecosystems.

The response of mineral-stabilized soil organic carbon (SOC) to environmental change is a source of uncertainty in the understanding of SOC cycling. Fluctuating wet-dry cycles and associated redox changes in otherwise well-drained soils may drive mineral dissolution, organic carbon (OC) mobilization, and subsequent OC mineralization. However, the extent to which rapid fluctuations between water-saturated and unsaturated conditions (i.e., flashy conditions) result in long-term changes in mineral composition and organo-mineral interactions is not well understood. In this study, the effect of variable saturation frequency on soil mineral composition, mineral-associated OC, and OC mineralizability was tested using selective dissolution, bulk spectroscopy, microscale imaging, and aerobic-anaerobic incubation experiments. Previous water table fluctuation measurements and diagnostic profile characteristics at Hubbard Brook Experimental Forest (NH) were used to identify soils with high, medium, and low saturation frequency regimes (defined by historical water table cycling frequency; i.e., water table presence and recession in the upper B horizon). We found the amount of OC released during extractions targeting non-crystalline minerals was of similar magnitude as extracted iron (Fe) in lower saturation frequency soils. However, the magnitude of extracted OC was 2.5 times greater than Fe but more similar to extractable aluminum (Al) in higher saturation frequency soils. Bulk soil Fe was spatially more strongly correlated to soil organic matter (SOM) in lower saturation frequency soils (Spearman Rank r(s) = 0.62, p < 0.005), whereas strong correlations between Al and SOM were observed in higher saturation frequency soils (r(s) = 0.88, p < 0.005) using nanoscale secondary ion mass spectrometry (NanoSIMS) imaging. Characterization of bulk soil Fe with X-ray absorption spectroscopy showed 1.2-fold greater Fe(II) and 1-fold lower contribution of Fe-organic bonding in soils with high saturation frequency. Fe(III) interactions with carboxylic and aromatic C were identified with C-13 nuclear magnetic resonance (NMR) spectroscopy Fe(III) interference experiments. Additionally, carboxylic acid enrichment in high saturation frequency soils quantified by C K-edge X-ray absorption spectroscopy point towards the role of carboxylic functional groups in Al-organic in addition to Fe-organic interactions. In our incubation experiments, a doubling in short-term CO2 evolution (per unit total soil C) was detected for high relative to low saturation frequency soils. Further, an order of magnitude increase in CO2 evolution (per unit water-extractable OC) following anaerobic incubation was only detected in high saturation frequency soils. The observed shift towards Al-dominated SOC interactions and higher OC mineralizability highlights the need to describe C stabilization in soils with flashy wet-dry cycling separately from soils with low saturation frequency or persistent saturation. ; NSF IGERT in Cross-Scale Biogeochemistry and Climate at Cornell University (NSF)National Science Foundation (NSF) [1069193]; Institute for Advanced Study (IAS) from the Technical University of Munich (TUM); Andrew W. Mellon Foundation; Cornell College of Agriculture and Life Sciences Alumni Foundation, USA; National Science FoundationNational Science Foundation (NSF) [DMR-1332208]; Canada Foundation for InnovationCanada Foundation for InnovationCGIAR; Natural Sciences and Engineering Research Council of CanadaNatural Sciences and Engineering Research Council of Canada (NSERC)CGIAR; University of Saskatchewan; Government of Saskatchewan; Western Economic Diversification Canada; National Research Council Canada; Canadian Institutes of Health Research, CanadaCanadian Institutes of Health Research (CIHR) ; Funding for this study was provided by the NSF IGERT in Cross-Scale Biogeochemistry and Climate at Cornell University (NSF Award #1069193) and the Institute for Advanced Study (IAS) from the Technical University of Munich (TUM) through the Hans-Fisher Senior Fellowship. Additional research funds were provided by the Andrew W. Mellon Foundation and the Cornell College of Agriculture and Life Sciences Alumni Foundation, USA. Hubbard Brook Experimental Forest is operated and maintained by the US Forest Service, Northern Research Station, Newtown Square, PA, USA. This work uses research conducted at the Cornell High Energy Synchrotron Source (CHESS) which is supported by the National Science Foundation under award DMR-1332208. Research was performed at the Canadian Light Source (CLS), which is supported by the Canada Foundation for Innovation, Natural Sciences and Engineering Research Council of Canada, the University of Saskatchewan, the Government of Saskatchewan, Western Economic Diversification Canada, the National Research Council Canada, and the Canadian Institutes of Health Research, Canada. The authors thank Dr. Rong Huang of CHESS, Dr. Tom Regier of CLS, Kelly Hanley and Akio Enders of Cornell University for technical assistance; Dr. Carmen Hoschen, Johann Lugmeier and Dr. Carsten Mueller of the Technical University of Munich for their support with the NanoSIMS measurements; Dr. Carmen Enid Martinez' research group for providing iron XAS standard materials; Dr. Linda Pardo, Stephanie Duston, Brittany LeBeau, and Johali Sotelo for soil sample collection and field characterization; and the referees for their invaluable insights. ; Public domain authored by a U.S. government employee