We quantified groundwater discharge and associated nutrient fluxes to Monterey Bay, California, during the wet and dry seasons using excess (224)Ra as a tracer. Bioassay incubation experiments were conducted to document the response of bloom-forming phytoplankton to submarine groundwater discharge (SGD) input. Our data indicate that the high nutrient content (nitrate and silica) in groundwater ...

Submarine groundwater discharge can significantly influence the near shore transport of chemicals into surface waters. Quantification of the sources and rates of such discharge is critical to development of management strategies. Quantification requires a groundwater seepage meter that provides continuous measurements at high resolutions over an extended period of time. An ultrasonic flow meter...

Tolo Harbour, located in the northeastern part of Hong Kong's New Territories, China, has a high frequency of algal blooms and red tides. An attempt was made to first quantify the submarine groundwater discharge (SGD) into Tolo Harbour using (226)Ra, and then to estimate the nutrient fluxes into the Harbour by this pathway. The total SGD was estimated to be 8.28×10(6) m(3) d(-1), while the fres...

Streambed temperatures can be easily, accurately and inexpensively measured at many locations. To characterize patterns of groundwater-stream water interaction with a high spatial resolution, we measured 140 vertical streambed temperature profiles along a 220m section of a small manmade stream. Groundwater temperature at a sufficient depth remains nearly constant while stream water temperatures...

In the eastern Grand Canyon, secondary porosity created by north trending faults, folds, and breccia pipes, facilitates groundwater flow through the South Rim carbonate aquifer. Springs associated with the South Rim Aquifer have low H concentrations, [Ca']/[Mg '] ratios close to unity, and variable uranium concentrations. For a geochemical comparison, springs are subcategorized on the basis of ...

Snowmelt dominates the hydrograph of many temperate montane streams, yet little work has characterized how streamwater sources and nitrogen (N) dynamics vary across wildland to urban land use gradients in these watersheds. Across a third-order catchment in Salt Lake City, Utah, we asked where and when groundwater vs shallow surface water inputs controlled stream discharge and N dynamics. Stream...

In the majority of lumped water balance models of river basins, groundwater is represented by a single reservoir, and groundwater discharge is described by a singlevalued function of storage in the reservoir. It is demonstrated that single-valued storagedischarge functions are often incapable of representing the actual storage-discharge characteristics of a river basin. An alternative discharge...

daily constant discharges are needed estimating daily discharge in the hydrological model. the different number of statistical years, statistical deficiencies, and measurement error leads to the formation of time series with an uncommon time base. hence the reconstruction of daily discharge data is of paramount importance. in this research, daily discharge was reconstructed in two stages in one...

Regional surveys of groundwater quality in Central Canterbury, from 1977 to the present, show widespread occurrence of nitrate contamination primarily from agricultural land use. Two reported analyses of these surveys, in 1984 and 2002, describe a general decrease of nitrate concentration with depth from the groundwater table to uncontaminated water at about 50-80 m. This high quality water is ...

Diffuse groundwater discharge (also known as vertical leakage) forms an important and poorly constrained component of the water balance of the Great Artesian Basin (GAB), Australia’s largest groundwater resource. Around the south-western margin of the GAB, the diffuse leakage from the artesian aquifer discharges into the unconfined water table and subsequently into the atmosphere via evapotrans...