A systematic summary is presented describing the application of isotope tracer method in detecting seepage flow in a single borehole. In a single borehole, many hydraulic coefficients, such as flow velocity, direction...A systematic summary is presented describing the application of isotope tracer method in detecting seepage flow in a single borehole. In a single borehole, many hydraulic coefficients, such as flow velocity, direction of flow, vertical flow etc., can be obtained by using isotope tracer method. There are three conditions if a fissure intersects a borehole: vertical, parallel and tilt. According to each different condition, the formulation of flow velocity deduced by isotope dilution method is different. At the same time, well theory of blended borehole about fissure groups including single fissure group and multi-fissure groups, has also been discussed.展开更多
Submarine groundwater discharges (SGD), consisting of groundwater flow from both terrestrial and marine origins, is an important source of nutrients, contaminants, and other chemicals to the coastal waters, and has si...Submarine groundwater discharges (SGD), consisting of groundwater flow from both terrestrial and marine origins, is an important source of nutrients, contaminants, and other chemicals to the coastal waters, and has significant impacts and implications on coastal environment and ecology. This paper reviews the recent advances in quantifying the tide-induced SGD in various beach aquifers around the world by means of mathematical modeling, laboratory experiments, and field observations or their combinations. Numerous studies have shown that (1) the order of magnitude of SGD around the world estimated by radium isotope tracers typically ranges from 102 to 103m3d-1m-1 of the shoreline, (2) SGD is mainly of marine origin, i.e. the re-circulated seawater across the aquifer-sea interface, and (3) tide is one of the major forces driving seawater-groundwater circulation. The order of magnitude of the tidal contributions to SGD from beach aquifers reported in the literature is only 10m3d-1m-1 length of shoreline, at least one order of magnitude smaller than the total SGD estimated by radium isotope tracers. This is obviously in contradiction with (3). The possible reasons for this contradiction may include (1) underestimation of the shoreline length due to neglecting many headlands, bays and banks of tidal rivers, and (2) negligence of the seawater-groundwater exchange from the seabed ranging from the nearshore areas to the continental shelf. Further research is needed to understand more about the contradiction.展开更多
基金Supported by Foundation for University Key Teacher by the Ministry of Education.
文摘A systematic summary is presented describing the application of isotope tracer method in detecting seepage flow in a single borehole. In a single borehole, many hydraulic coefficients, such as flow velocity, direction of flow, vertical flow etc., can be obtained by using isotope tracer method. There are three conditions if a fissure intersects a borehole: vertical, parallel and tilt. According to each different condition, the formulation of flow velocity deduced by isotope dilution method is different. At the same time, well theory of blended borehole about fissure groups including single fissure group and multi-fissure groups, has also been discussed.
基金supported by the Outstanding Young Scientists of the National Natural Science Foundation of China (41025009)the Research Grants Council of Hong Kong (HKU702611)
文摘Submarine groundwater discharges (SGD), consisting of groundwater flow from both terrestrial and marine origins, is an important source of nutrients, contaminants, and other chemicals to the coastal waters, and has significant impacts and implications on coastal environment and ecology. This paper reviews the recent advances in quantifying the tide-induced SGD in various beach aquifers around the world by means of mathematical modeling, laboratory experiments, and field observations or their combinations. Numerous studies have shown that (1) the order of magnitude of SGD around the world estimated by radium isotope tracers typically ranges from 102 to 103m3d-1m-1 of the shoreline, (2) SGD is mainly of marine origin, i.e. the re-circulated seawater across the aquifer-sea interface, and (3) tide is one of the major forces driving seawater-groundwater circulation. The order of magnitude of the tidal contributions to SGD from beach aquifers reported in the literature is only 10m3d-1m-1 length of shoreline, at least one order of magnitude smaller than the total SGD estimated by radium isotope tracers. This is obviously in contradiction with (3). The possible reasons for this contradiction may include (1) underestimation of the shoreline length due to neglecting many headlands, bays and banks of tidal rivers, and (2) negligence of the seawater-groundwater exchange from the seabed ranging from the nearshore areas to the continental shelf. Further research is needed to understand more about the contradiction.
