Potential climate change impacts on the water balance of regional unconfined aquifer systems in south-western Australia
38
Citation
53
Reference
10
Related Paper
Citation Trend
Abstract:
Abstract. This study assesses climate change impacts on water balance components of the regional unconfined aquifer systems in south-western Australia, an area that has experienced a marked decline in rainfall since the mid 1970s and is expected to experience further decline due to global warming. Compared with the historical period of 1975 to 2007, reductions in the mean annual rainfall of between 15 and 18 percent are expected under a dry variant of the 2030 climate which will reduce recharge rates by between 33 and 49 percent relative to that under the historical period climate. Relative to the historical climate, reductions of up to 50 percent in groundwater discharge to the ocean and drainage systems are also expected. Sea-water intrusion is likely in the Peel-Harvey Area under the dry future climate and net leakage to confined systems is projected to decrease by up to 35 percent which will cause reduction in pressures in confined systems under current abstraction. The percentage of net annual recharge consumed by groundwater storage, and ocean and drainage discharges is expected to decrease and percentage of net annual recharge consumed by pumping and net leakage to confined systems to increase under median and dry future climates. Climate change is likely to significantly impact various water balance components of the regional unconfined aquifer systems of south-western Australia. We assess the quantitative climate change impact on the different components (the amounts) using the most widely used GCMs in combination with dynamically linked recharge and physically distributed groundwater models.Keywords:
Water balance
Response of groundwater table to rainfall in a diluvial upland is analyzed by the weighted mean method developed by Tsuboi (1941). This method employs the Fourier series based on the assumption of periodic waves of the input and output. The groundwater level has been used as an output for analysis in previous studies (e. g. Hirata, 1971). The authors employ the amount of groundwater :recharge as :the output because it is the amount of groundwater recharge that directly causes changes in groundwater level. The analysis is also carried out using the groundwater level as the output and the results are compared with that using the amount of groundwater recharge. Results obtained are as follows: 1. The time lag between the rainfall and the amount of groundwater recharge is about 10 days for wells whose groundwater levels are about 70 to 80 meters below the surface. 2. The groundwater level is affected by rainfall with a time lag of about 3 months. This coincides with a theoretically derived phase difference of π/2. 3. It may be said that results mentioned above give support to the pressure transmission theory as one of the important groundwater recharge mechanisms.
Depression-focused recharge
Cite
Citations (3)
The balance between groundwater availability and soil water requirements should always be maintained, so that the quantity and quality of the ground water remains sustainable. The development of Manggar city located in Ngarawan watershed, it is feared will disrupt the balance of ground water. The decrease of ground water level has been felt by the community during the dry season, so that the ground water balance analysis is needed, to know the balance between the availability and the need of ground water in Ngarawan watershed. The research method consists of calculation of ground water balance, groundwater requirement, geometric method, and descriptive analysis. The results show that the condition of ground water balance in Ngarawan watershed is still surplus, with changes in ground water savings of 8,903,116.38 m3 in 2016, but reduced to 3,468,570.18 m3 in 2034. Reduced changes in groundwater storage, due to changes land use and increased groundwater demand.
Water balance
Cite
Citations (1)
Groundwater is critical in supporting current and future reliable water supply throughout Africa. Although continental maps of groundwater storage and recharge have been developed, we currently lack a clear understanding on how the controls on groundwater recharge vary across the entire continent. Reviewing the existing literature, we synthesize information on reported groundwater recharge controls in Africa. We find that 15 out of 22 of these controls can be characterised using global datasets. We develop 11 descriptors of climatic, topographic, vegetation, soil and geologic properties using global datasets, to characterise groundwater recharge controls in Africa. These descriptors cluster Africa into 15 Recharge Landscape Units for which we expect recharge controls to be similar. Over 80% of the continents land area is organized by just nine of these units. We also find that aggregating the Units by similarity into four broader Recharge Landscapes (Desert, Dryland, Wet tropical and Wet tropical forest) provides a suitable level of landscape organisation to explain differences in ground-based long-term mean annual recharge and recharge ratio estimates. Furthermore, wetter Recharge Landscapes are more efficient in converting rainfall to recharge than drier Recharge Landscapes as well as having higher annual recharge rates. In Dryland Recharge Landscapes, we found that annual recharge rates largely varied according to mean annual precipitation, whereas recharge ratio estimates increase with increasing monthly variability in P-PET. However, we were unable to explain why ground-based estimates of recharge signatures vary across other Recharge Landscapes, in which there are fewer ground-based recharge estimates, using global datasets alone. Even in dryland regions, there is still considerable unexplained variability in the estimates of annual recharge and recharge ratio, stressing the limitations of global datasets for investigating ground-based information.
Depression-focused recharge
Cite
Citations (0)
This chapter contains sections titled: Recharge Applications Design Objectives Potential Problems with Recharge Water and Plugging of Wells Sources of Recharge Water Treatment of Recharge Water Construction of Recharge Systems Operation and Maintenance of Recharge Systems Permits for Recharge Operations
Depression-focused recharge
Cite
Citations (0)
The method of recharge groundwater by deep well is used widely.Because the well is adapt to be clogged,this method usually has high requirement for water quality.This made the efficiency of the recharge being low,and corresponding cost increased greatly.A new method,SPD artificial recharge system,is put forward.Through simulation experiment in lab,the new method is compared with direct well recharge.Study showed that the new method is an effective way to recharge deep groundwater.It has the advantage of low requirement for water quality,high speed of recharging,larger amount of recharge and anti-clogging etc.
Clogging
Depression-focused recharge
Cite
Citations (1)
Depression-focused recharge
Cite
Citations (19)
The methods used to recharge groundwater by deep wells are adopted widely.Because of the tendency of being clogged and high requirement for water quality,the efficiency of recharge is decreased and correspondingly the cost of recharge operation is greatly increased.In this paper,a new method,SPD artificial recharge system,is put forward.Through simulation experiments in labs,the new method is compared with direct well recharge in the field.The results indicate that this new method is an effective way to recharge deep-seated groundwater with such characteristics as low requirement for water quality,high speed to recharge,large amount of recharge and anti-clogging,etc.
Depression-focused recharge
Clogging
Cite
Citations (1)
An experimental study of groundwater recharge by means of recharge basin has been done in a dune area of Showamachi, Akita Prefecture. Raw water source was withdrawn from the Hachirogata regulating reservoir. The purpose of this study is to make certain of storage of recharge water and changes in water quality. The experimental equipments consist mainly of a recharge basin (area of 10× 20 m and 0.4 m deep), a pumping well (14 m deep) and six observation wells (each 8 m deep). Water was analyzed in laboratory. The structural phases of the equipments are explained in this paper. Results obtained are discussed in the following papers.
Depression-focused recharge
Cite
Citations (0)
Analytical methods of assessing the response of groundwater levels to a range of factors, including elastic (barometric and tidal) influences in confined aquifers and recharge to unconfined aquifers due to infiltration of rain and other surface water, are presented. Responses in a confined aquifer to distant recharge events and the associated time lag is discussed. Also covered are responses to changes in storage volume resulting from direct recharge at the outcrop of an unconfined aquifer system both seasonally and on a single recharge event basis. Worked examples and case histories are used to illustrate methods of estimating the amount of recharge at different sites within a catchment. The application of vertical cross-sectional flow nets to the estimation of recharge is presented in the context of recharge/discharge profiles.
Depression-focused recharge
Infiltration (HVAC)
Cite
Citations (4)
In order to discuss the effects of geothermal well recharge,taking the geothermal well in Dagang District of Tianjin City as an example,four recharge modes are adopted for experiments.The recharge capacity,possible recharge duration,accumulation recharge dynamic water level and diachronic variation of injectivity index under the four modes are analyzed.The experimental results show that the recharge duration is short and recharge capacity is poor under the mode of natural intermission;in the lifting-recharge mode,the longer the pump lifting time is,the longer the recharge duration is and the more the recharge volume is.The recharge volume under the pressure mode is decreasing.The operation mode influences the recharge capacity of the system greatly.
Depression-focused recharge
Mode (computer interface)
Cite
Citations (0)