Ground water recharge is often estimated through the calibration of ground water flow models. We examine the nature of calibration errors by considering some simple mathematical and numerical calculations. From these calculations, we conclude that calibrating a steady-state ground water flow model to water level extremes yields estimates of recharge that have the same value as the time-varying ...

A regional regression model was developed to estimate the spatial distribution of ground water recharge in subhumid regions. The regional regression recharge (RRR) model was based on a regression of basin-wide estimates of recharge from surface water drainage basins, precipitation, growing degree days (GDD), and average basin specific yield (SY). Decadal average recharge, precipitation, and GDD...

The linear mathematical model for springflow suggested by Bear (1979) can simulate springflow for an initial instantaneous recharge. A springflow model has been developed, using the Bear model and Duhamel's approach, which can simulate springflow for time variant recharge. The suggested model can also be used to compute the time variant recharge to the springflow domain from a given springflow ...

An overview is presented of existing groundwater-age data and their implications for assessing rates and timescales of recharge in selected unconfined aquifer systems of the United States. Apparent age distributions in aquifers determined from chlorofluorocarbon, sulfur hexafluoride, tritium/helium-3, and radiocarbonmeasurements from 565 wells in 45 networks were used to calculate groundwater r...

Mobilization of natural nitrate (NO3-) deposits in the subsoil by irrigation water in arid and semiarid regions has the potential to produce large groundwater NO3-concentrations. The use of isotopes to distinguish between natural and anthropogenic NO3- sources in these settings could be complicated by the wide range in delta15N values of natural NO3-. An approximately 10 000 year record of pale...

Driverless plug-in electric vehicles (DPEVs) have attracted a growing attention in transport engineering due to their low environmental impact and increased level of automation. When compared to regular internal combustion engine vehicles, DPEVs have two characteristics: 1) DPEVs require a higher frequency of recharge operations; 2) DPEVs are controlled by predetermined intelligent algorithms, ...

[1] Groundwater recharge is likely to be affected by climate change. In semiarid regions where groundwater resources are often critical, annual recharge rates are typically small and most recharge occurs episodically. Such episodic recharge is uncertain and difficult to predict. This paper analyzes the impacts of different climate predictions on diffuse episodic recharge at a low‐relief semiari...

One of the suggested approaches to mitigate chronic groundwater depletion in California is agricultural managed aquifer recharge (Ag-MAR), which farmland flooded using excess surface water order underlying aquifer. Successful implementation Ag-MAR projects requires careful estimation soil aeration status, as prolonged saturated conditions rhizosphere can damage crops due O2 deficiency. We studi...