Despite its purported importance, previous studies of the influence sea-level rise on coastal aquifers have focused specific sites, and a generalized systematic analysis general case sea water intrusion response to has not been reported. In this study, simple conceptual framework is used provide first-order assessment changes in unconfined rise. Two models are tested: (1) flux-controlled systems, which ground discharge persistent despite level, (2) head-controlled whereby abstractions or...

The argument that human society can decouple economic growth-defined as growth in Gross Domestic Product (GDP)-from environmental impacts is appealing. If such decoupling possible, it means GDP a sustainable societal goal. Here we show the concept be interpreted using an easily understood model of and impact. simple compared to historical data modelled projections demonstrate ultimately cannot decoupled from material energy use. It therefore misleading develop growth-oriented policy around...

Abstract Drought is an intermittent disturbance of the water cycle that profoundly affects terrestrial carbon cycle. However, response coupled and cycles to drought underlying mechanisms remain unclear. Here we provide first global synthesis effect on ecosystem use efficiency (WUE = gross primary production (GPP)/evapotranspiration (ET)). Using two observational WUE datasets (i.e., eddy-covariance measurements at 95 sites (526 site-years) gridded diagnostic modelling based existing...

Abstract River‐groundwater interactions are at the core of a wide range major contemporary challenges, including provision high‐quality drinking water in sufficient quantities, loss biodiversity river ecosystems, or management environmental flow regimes. This paper reviews state art approaches characterizing and modeling groundwater interactions. Our review covers approaches, remote sensing to characterize streambed, emerging methods measure exchange fluxes between rivers groundwater,...

Understanding how changes in the groundwater table affect surface water resources is of fundamental importance quantitative hydrology. If below a stream sufficiently deep, position effectively do not alter infiltration rate. This referred to as disconnected system. Previous authors noted that low‐conductivity layer body necessary but sufficient criterion for disconnection occur. We develop precise allows an assessment whether water–groundwater systems can disconnect or not. further...

In this paper, simple indicators of the propensity for sea water intrusion (SWI) to occur (referred as “SWI vulnerability indicators”) are devised. The analysis is based on an existing analytical solution steady‐state position a sharp fresh water‐salt interface. Interface characteristics, that is, wedge toe location and volume, used in quantifying SWI both confined unconfined aquifers. Rates‐of‐change (partial derivatives solution) or volume quantify aquifer various stress situations,...

Abstract The use of hydraulic head measurements in ground water variable density is considerably more complicated than for the case constant‐density water. A theoretical framework dealing with these complications does exist current literature but suffers from a lack awareness among many hydrogeologists. When corrections variations are ignored or not properly taken into account, misinterpretation both flow direction and magnitude may result. This paper summarizes existing provides practical...

Abstract Water‐limited ecosystems, covering ~50% of the global land, are controlled primarily by hydrologic factors. Because climate change is predicted to markedly alter current hydroclimatic conditions later this century, a better hydrological indicator ecosystem performance warranted improve understanding controls on vegetation and predict changes in future. Here we show that observed total water storage anomaly (TWSA) from Gravity Recovery Climate Experiment (GRACE) can serve as...

Understanding seawater intrusion (SWI) induced by sea level rise (SLR) is important for the future management of many coastal aquifers. Only simplified steady state sharp interface analyses generalized SLR‐SWI exist in literature, and issue associated time scales has been neglected. We employ numerical modeling order to explore transience dispersive common unconfined aquifer settings. An instantaneous SLR adopted compare with drop (SLD) case a previous SLD‐SWI analysis. Temporal asymmetry...

Abstract The fresh groundwater lenses (FGLs) of small islands can be highly vulnerable to climate change impacts, including sea‐level rise (SLR). Many real cases atoll or sandy involve two‐layer hydrogeological conceptualizations. In this paper, the influential factors that affect FGLs in subject SLR are investigated. An analytical solution describing circular islands, composed two geological layers, is developed for simplified case steady‐state and sharp‐interface conditions. application...

Abstract Various remote sensing‐based terrestrial evapotranspiration (ET) models have been developed during the past four decades. These vary in conceptual and mathematical representations of physics, consequently leading to different performances. Examination uncertainties associated with limitations model physics will be useful for selection improvement. Here, three dual‐source sensing ET (i.e., Hybrid scheme Trapezoid framework‐based Model (HTEM), Two‐Source Energy Balance (TSEB) model,...

Apparent ages obtained from the measured concentrations of environmental tracers have potential to inform recharge rates, flow and assist in calibration groundwater models. A number studies investigated sources error relationships between apparent ages, age assumed by models relate this quantity an aquifer property (e.g., recharge). These also provided a techniques for correcting known biases ages. In paper, we review some concepts bias. We then demonstrate bias through use on four numerical...

The electronic structure of the ${\mathrm{CuO}}_{2}$ planes and ${\mathrm{CuO}}_{3}$ chains in single-domain crystals ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{\mathit{x}}$ has been investigated as a function oxygen concentration (6\ensuremath{\le}x\ensuremath{\le}7) using polarization-dependent x-ray-absorption spectroscopy O 1s Cu 2p core levels. observation unoccupied states with orbital character parallel to a, b, c axes allows determination number hole...

Y1-xPrxBa2Cu3O7-δ compounds exhibit a progressive decrease in superconducting transition temperature with increasing x. Using soft-X-ray absorption spectroscopy at the Pr-MIV,V thresholds, Pr is shown to be trivalent for all x these contrary expectations, excluding an obvious mechanism suppression of Tc based on tetravalency Pr. From discussion other possible mechanisms it suggested that decreases through changes electronic-band structure upon substitution leading ultimately semiconducting...

The accuracy with which MODFLOW simulates surface water-groundwater interaction is examined for connected and disconnected losing streams. We compare the effect of different vertical horizontal discretization within also simulations those produced by HydroGeoSphere. HydroGeoSphere able to simulate both saturated unsaturated flow, as well water, groundwater full coupling between them in a physical way, so used reference code quantify influence some simplifying assumptions MODFLOW. In...