Understanding and mitigating against the impact of groundwater extraction on groundwater-dependent ecosystems(GDE)requires information of evapotranspiration(ET)of these ecosystems.In this pilot study,we tested two re...Understanding and mitigating against the impact of groundwater extraction on groundwater-dependent ecosystems(GDE)requires information of evapotranspiration(ET)of these ecosystems.In this pilot study,we tested two remotesensing methods,Surface Energy Balance Algorithms for Land(SEBAL)and Vegetation Index/Temperature Trapezoid(VITT),for ET estimation from terrestrial GDEs.Multi-temporal Landsat Thematic Mapper(TM)and Enhanced Thematic Mapper(ETM)images were used to derive vegetation indices and land surface temperatures for ET estimation.Radiative transfer model was used for atmospheric correction of the Landsat images.Field measurements were used to validate the remote sensing estimation of VI and surface temperature.Both methods have been implemented in a geographic information system(GIS)using automated scripts and ancillary GIS data for quality control process.Comparison of predicted ET by SEBAL to VITT model indicates relatively good agreement(R20.90)and promise for use in groundwater management.The average ET from woodland GDEs within the zone of influence of the pumping stations is in general lower than similar woodlands outside of the pumping area,particularly in summer seasons which demonstrates that the pumping regime has an impact on those GDEs.The study also demonstrates that even a simple physical ET model can provide useful information for groundwater management,and more broadly other applications in hydrologic modelling and digital earth studies.展开更多
Subaerial fallout from the Holocene eruption of Mount Mazama in the Oregon Cascade Range was deposited upon relatively low permeability volcanic and volcaniclastic bedrock and regolith. In the Walker Rim study area, e...Subaerial fallout from the Holocene eruption of Mount Mazama in the Oregon Cascade Range was deposited upon relatively low permeability volcanic and volcaniclastic bedrock and regolith. In the Walker Rim study area, erosion by ephemeral streams shortly after the eruption disrupted the lateral continuity of the 270 to 300 cm-thick pumice deposit. Co-evolution of the surface- and ground-water systems in a low-relief, low-slope landscape allowed diffuse groundwater discharge from the banks of the evolving stream system. Accumulation of organic material from groundwater dependent ecosystems at these sites of discharge allowed peat deposits to form on gently sloping erosion surfaces cut into the pumice deposit. Following early stream incision, fine-grained, silt-rich deposits accumulated in valleys and contributed permeability barriers to the lateral migration of water in the pumice aquifer. Fens discharge from the pumice aquifer through gently sloping surfaces patterned after the slope of the erosion surface cut into the pumice deposit and overlain by approximately 1 m of peat on the sloping surface and alluvium or iron-cemented pumice overlain by alluvium at the toe of the slope. The predominant source of groundwater is snowmelt which infiltrates the pumice deposit during the freshet. However, shallow groundwater flow also takes place along permeable pathways in bedrock units. Locally, low volume discharge takes place along faults. The snowmelt-dependent hydrologic system that supports the fens of the Walker Rim study area occurs at elevations primarily above 1585 m.展开更多
This research project investigates the current status of water supply, sanitation, and hygiene practices in Munshiganj District, Bangladesh. Data collection involved a structured questionnaire and a reconnaissance sur...This research project investigates the current status of water supply, sanitation, and hygiene practices in Munshiganj District, Bangladesh. Data collection involved a structured questionnaire and a reconnaissance survey. Findings reveal that 30% of individuals rely on surface water (hand-tube wells, rivers, and ponds), prioritized as canal > river > pond, while 70% depend on groundwater (subterranean electric motor, deep tube-well). Drinking water is generally sufficient, with 95% reporting adequacy throughout the year. About 45% use hand tube-well water, 28% use deep tube-well water, and 11% use supply tap water for various purposes. Bathing trends include underground water through electric motor > pond > hand tube-well water > river, while for cooking, the order is underground water through electric motor > pond > hand tube-well water > river. Toilet water supply ranks as supply tap water > hand tube-well water > deep tube-well water. Although sanitation awareness is high, some lack knowledge of good hygiene practices. After defecating, handwashing methods include soap, ash, soil, or water. Children’s waste disposal varies, with some discarding it in open areas. Approximately 40% suffer from diseases like Diarrhoea due to unsafe water, primarily affecting children and elders. Training exists, but a significant portion lacks sanitation education. Dry skin or exposure to cold water may cause temporary irritation. Local government involvement in sanitation efforts is less active compared to non-governmental organizations. Results emphasize the need to enhance community awareness of safe water supplies and sanitation practices. .展开更多
基金This project was funded by the GDE project from the NSW Government. Many DECCWstaff helped and supported this project.
文摘Understanding and mitigating against the impact of groundwater extraction on groundwater-dependent ecosystems(GDE)requires information of evapotranspiration(ET)of these ecosystems.In this pilot study,we tested two remotesensing methods,Surface Energy Balance Algorithms for Land(SEBAL)and Vegetation Index/Temperature Trapezoid(VITT),for ET estimation from terrestrial GDEs.Multi-temporal Landsat Thematic Mapper(TM)and Enhanced Thematic Mapper(ETM)images were used to derive vegetation indices and land surface temperatures for ET estimation.Radiative transfer model was used for atmospheric correction of the Landsat images.Field measurements were used to validate the remote sensing estimation of VI and surface temperature.Both methods have been implemented in a geographic information system(GIS)using automated scripts and ancillary GIS data for quality control process.Comparison of predicted ET by SEBAL to VITT model indicates relatively good agreement(R20.90)and promise for use in groundwater management.The average ET from woodland GDEs within the zone of influence of the pumping stations is in general lower than similar woodlands outside of the pumping area,particularly in summer seasons which demonstrates that the pumping regime has an impact on those GDEs.The study also demonstrates that even a simple physical ET model can provide useful information for groundwater management,and more broadly other applications in hydrologic modelling and digital earth studies.
文摘Subaerial fallout from the Holocene eruption of Mount Mazama in the Oregon Cascade Range was deposited upon relatively low permeability volcanic and volcaniclastic bedrock and regolith. In the Walker Rim study area, erosion by ephemeral streams shortly after the eruption disrupted the lateral continuity of the 270 to 300 cm-thick pumice deposit. Co-evolution of the surface- and ground-water systems in a low-relief, low-slope landscape allowed diffuse groundwater discharge from the banks of the evolving stream system. Accumulation of organic material from groundwater dependent ecosystems at these sites of discharge allowed peat deposits to form on gently sloping erosion surfaces cut into the pumice deposit. Following early stream incision, fine-grained, silt-rich deposits accumulated in valleys and contributed permeability barriers to the lateral migration of water in the pumice aquifer. Fens discharge from the pumice aquifer through gently sloping surfaces patterned after the slope of the erosion surface cut into the pumice deposit and overlain by approximately 1 m of peat on the sloping surface and alluvium or iron-cemented pumice overlain by alluvium at the toe of the slope. The predominant source of groundwater is snowmelt which infiltrates the pumice deposit during the freshet. However, shallow groundwater flow also takes place along permeable pathways in bedrock units. Locally, low volume discharge takes place along faults. The snowmelt-dependent hydrologic system that supports the fens of the Walker Rim study area occurs at elevations primarily above 1585 m.
文摘This research project investigates the current status of water supply, sanitation, and hygiene practices in Munshiganj District, Bangladesh. Data collection involved a structured questionnaire and a reconnaissance survey. Findings reveal that 30% of individuals rely on surface water (hand-tube wells, rivers, and ponds), prioritized as canal > river > pond, while 70% depend on groundwater (subterranean electric motor, deep tube-well). Drinking water is generally sufficient, with 95% reporting adequacy throughout the year. About 45% use hand tube-well water, 28% use deep tube-well water, and 11% use supply tap water for various purposes. Bathing trends include underground water through electric motor > pond > hand tube-well water > river, while for cooking, the order is underground water through electric motor > pond > hand tube-well water > river. Toilet water supply ranks as supply tap water > hand tube-well water > deep tube-well water. Although sanitation awareness is high, some lack knowledge of good hygiene practices. After defecating, handwashing methods include soap, ash, soil, or water. Children’s waste disposal varies, with some discarding it in open areas. Approximately 40% suffer from diseases like Diarrhoea due to unsafe water, primarily affecting children and elders. Training exists, but a significant portion lacks sanitation education. Dry skin or exposure to cold water may cause temporary irritation. Local government involvement in sanitation efforts is less active compared to non-governmental organizations. Results emphasize the need to enhance community awareness of safe water supplies and sanitation practices. .
