Increase In Groundwater Level Research Articles

Inverse modelling of aquifer parameters in basaltic rock with the help of pumping test method using MODFLOW software

The origin and movement of groundwater are the fundamental questions that address both the temporal and spatial aspects of ground water run and water supply related issues in hydrological systems. As groundwater flows through an aquifer, its composition and temperature may variation dependent on the aquifer condition through which it flows. Thus, hydrologic investigations can also provide useful information about the subsurface geology of a region. But because such studies investigate processes that follow under the Earth's shallow, obtaining the information necessary to answer these questions is not continuously easy. Springs, which discharge groundwater table directly, afford to study subsurface hydrogeological processes.The present study of estimation of aquifer factors such as transmissivity (T) and storativity (S) are vital for the evaluation of groundwater resources. There are several methods to estimate the accurate aquifer parameters (i.e. hydrograph analysis, pumping test, etc.). In initial days, these parameters are projected either by means of in-situ test or execution test on aquifer well samples carried in the laboratory. The simultaneous information on the hydraulic behavior of the well (borehole) that provides on this method, the reservoir and the reservoir boundaries, are important for efficient aquifer and well data management and analysis. The most common in-situ test is pumping test performed on wells, which involves the measurement of the fall and increase of groundwater level with respect to time. The alteration in groundwater level (drawdown/recovery) is caused due to pumping of water from the well. Theis (1935) was first to propose method to evaluate aquifer parameters from the pumping test on a bore well in a confined aquifer. It is essential to know the transmissivity (T = Kb, where b is the aquifer thickness; pumping flow rate, Q = TW (dh/dl) flow through an aquifer) and storativity (confined aquifer: S = bSs, unconfined: S = Sy), for the characterization of the aquifer parameters in an unknown area so as to predict the rate of drawdown of the groundwater table/potentiometric surface throughout the pumping test of an aquifer. The determination of aquifer's parameters is an important basis for groundwater resources evaluation, numerical simulation, development and protection as well as scientific management. For determining aquifer's parameters, pumping test is a main method. A case study shows that these techniques have been fast speed and high correctness. The results of parameter's determination are optimized so that it has important applied value for scientific research and geology engineering preparation.

Evaluation of Deterioration and Proposed Restoration of the Limestone, White Monastery—Sohag, Egypt

By studying the phenomena of limestone built from the White Monastery in Sohag Governorate damage where this study discusses the results of the analyzes and the study’s petrographic limestone, we can study and discuss what has been done to analyze X-ray diffraction and X-ray flourecence, and by scanning electron microscope in order to determine the cause of the damage and to study the properties of limestone to choose the most appropriate treatment methods especially the internal structure affected by the environmental conditions surrounding the private and increasing ground water levels along with the use of the most appropriate ways to buffer water to conserve the limestone of the environmental factors that damage it.

Climate change adaptation in urban areas. Case study for the Tineretului area in Bucharest

Abstract Urban drainage systems are loaded directly by precipitation and snow melting processes and their hydraulic capacity must be sufficient to be able to convey the water volumes without discharging to the surface causing flooding. Urban drainage systems are also affected by the groundwater levels by increasing the water volumes that are transported through the system. The receiving waters may also be affected by climate change in terms of higher water levels which can have significant back water effects and reduced outlet discharge capacity in the urban drainage system [1]. Climate change may lead to an increased groundwater level which affects the urban drainage system by additional volumes infiltrated into the sewer from the underground. This infiltration may lead to a reduction of the hydraulic capacity of the collection system and in increased pressure over the wastewater treatment plant. The increased groundwater level can affect the percolation process and may lead to local flooding and reduced hydraulic capacity in the urban drainage system [1].

To the question of conditions, factors and criteria of geodynamic risk in the boundaries of urban areas

Formulation of the problem Loess deposits are widespread. They are characterized by the singular difficult deformations, therefore, their structure collapses. We have shown in the previous researches that in a zone of influence of the city properties of rocks change over time. Physical condition and gradation of microaggregates change over time as well. As a result, complex changes of physical properties occur. The duration of moistening affects the type and magnitude of the changes. Microaggregates do not disintegrate when the duration of moisture is short. When the duration of moisture is long, disintegration of the microaggregates is accompanied by the re-packaging and increasing of the endurance.The purpose of the article. The forecast of relative subsidence values and endurance can be performed using statistical analysis and group accounting method arguments. In this paper, we show the possibilities of forecasting using the example of a concrete construction site.Methods. Statistical method and the method of inductive modeling by group accounting of arguments were used in prognostic researches. In calculation of subsidence in the zone influences and stability analyses we used standard methods.Results. The object of research is an elementary natural and technical system formed by a projected building. The house will be built in the zone of distribution of loess’s (the erosion basin Vstrechnaya, Dnipro). The groundwater level in erosion basin is at a depth of 0.5 to 14.0 m. The magnitude of the increase of Groundwater level is 1.55 m from the modeling results in the research area. According to the results of multi-year data statistical analysis, close correlation relations between the property indices, regression between indicators of the physical state was found. The forecast values of mechanical properties' indicators are established as the results of inductive modeling with the method of group accounting of arguments. The forecast values of humidity and other indicators of the physical state, the content of individual fractions were set as well. The values were calculated to characterize a moderate and intensive change in soil properties in comparison with the natural state. Deformation calculations in the ground base and stability analysis were performed by standard analytical methods.Scientific novelty and practical significance. The following variants of events were considered: long-term or short-term humidification, complete or selective change in indicators of the physical condition of soils and microaggregate structure. The loss of strength is most likely to happen in case of emergency soaking of soils when the physical state changes but dispersion do not change.

The Influence of Groundwater Depletion from Irrigated Agriculture on the Tradeoffs between Ecosystem Services and Economic Returns.

An irrigated agricultural landscape experiencing groundwater overdraft generates economic returns and a suite of ecosystem services (in particular, groundwater supply, greenhouse gases reduction, and surface water quality). Alternative land cover choices indicate tradeoffs among the value of ecosystem services created and the economic returns. These tradeoffs are explored using efficiency frontiers that determine the least value in ecosystem services that must be given up to generate additional economic returns. Agricultural producers may switch to irrigation with surface water using on-farm reservoirs and tail water recovery systems in response to groundwater overdraft, and this has consequences for the bundle of ecosystem service values and economic returns achievable from the landscape. Planning that accounts for both ecosystem service value and economic returns can achieve more value for society, as does the adoption of reservoirs though lowering the costs of irrigation, increasing groundwater levels, and reducing fuel combustion and associated GHG emissions from groundwater pumping. Sensitivity analyses of per unit value of ecosystem services, crop prices, and the groundwater and water purification model parameters indicate tradeoff among ecosystems service values, such as the use of a high-end social cost of carbon ultimately lowers groundwater supply and water purification value by more than 15%.

Modelling impacts of acid deposition and groundwater level on habitat quality and plant species diversity

We quantified the effects of the site factors pH and nitrate (NO3) concentration in soil solution and groundwater level on the vegetation of terrestrial ecosystems for the Netherlands in response to changes in atmospheric nitrogen (N) and sulphur (S) deposition and groundwater level over the period 1990–2030. The assessment was made with the SMART2 model, a simple one-layer model including geochemical buffer processes, element cycling by litterfall, mineralisation and uptake, nitrogen transformation processes and element input through deposition, weathering and upward seepage. To assess the effects of changes in abiotic site factors on the vegetation, we developed a simple plant diversity indicator for grassland, heathland and forest, based on the occurrence of target plant species and competing species. Species occurrence was calculated from the preferred ranges of each species for the NO3 concentration and pH in soil solution and mean spring groundwater level. Changes in the plant diversity indicator were assessed from effects of changes in the occurrence of target and competing plant species in response to changes in mean spring groundwater level and in pH and NO3 concentration, as calculated with SMART2. Calculations were made for combinations of five vegetation structure types (three forest types, semi-natural grassland and heathland) and seven soil types (three sandy soils, two clay soils, peat and loess soils) using a 250 × 250 m grid. We used data for atmospheric deposition and groundwater level in the past to assess trends between 1990 and 2010 and evaluated two future scenarios for the period 2010–2030: a Business as Usual and an Improved Environment scenario. Comparison of model predictions on pH and NO3 with measured soil solution concentrations for forest showed a reasonable to good agreement for pH but rather poor for NO3. The largest impacts were found for the combination of the two Improved Environment scenarios. Reductions in N and S deposition and an increase in groundwater level between 1990 and 2030 hardly caused changes in soil pH and only relatively small reductions in NO3 concentration (11–13%). Nevertheless, those changes caused a significant increase in plant diversity indicator.

Hydrologic impact of urbanization with extensive stormwater infiltration

This paper presents a novel modeling analysis of a 40-year-long dataset to examine the impact of urbanization, with widespread stormwater infiltration, on groundwater levels and the water balance of a watershed. A dataset on the hydrologic impact of urbanization with extensive stormwater infiltration is not widely available, and is important because many municipalities are considering infiltration as an alternative to traditional stormwater systems. This study analyzes groundwater level observations from an urban catchment located in Perth, Western Australia. The groundwater observation data cover approximately a 40-year-long period where land use changes (particularly due to urbanization) occurred; moreover, the monitored area contains both undeveloped and urbanized areas where stormwater infiltration is common practice via soakwells (shallow vertical infiltration wells). The data is analyzed using a distributed and dynamic hydrological model to simulate the groundwater response. The model explicitly couples a soakwell model with a groundwater model so that the performance of the soakwells is reduced by the increase of groundwater levels. The groundwater observation data is used to setup, calibrate and validate a coupled MIKE SHE-MIKE URBAN groundwater model and the model is used to quantify the extent of groundwater rise as a result of the urbanization process. The modeled urbanization processes included the irrigation of new established private and public gardens, the reduction of evapotranspiration due to a decrease in green areas, and the development of artificial stormwater infiltration. The study demonstrates that urbanization with stormwater infiltration affects the whole catchment water balance, increasing recharge and decreasing evapotranspiration. These changes lead to a rise in the groundwater table and an increase in the probability of groundwater seepage above terrain.

The Tradeoffs between Market Returns from Agricultural Crops and Non-Market Ecosystem Service Benefits on an Irrigated Agricultural Landscape in the Presence of Groundwater Overdraft

Groundwater overdraft has consequences in the long-run for the economic and ecological sustainability of an agricultural landscape. In response to aquifer depletion, we examine the tradeoff of non-market ecosystem service benefits (e.g., groundwater supply, greenhouse gases, and surface water quality) and market returns from crops in the Lower Mississippi River Delta. Farmers may turn to conjunctive water management using on-farm reservoirs and tail water recovery when groundwater pumping becomes expensive. We use separate objectives for market returns from crops and the non-market benefits of ecosystem services to study whether on-farm reservoirs are built with optimal cropping and irrigation choices. The use of reservoirs enables the landscape to attain up to 10% higher market returns for a given level of all non-market ecosystem service benefits by lowering the costs of irrigation, increasing groundwater levels, and reducing fuel combustion and associated greenhouse gas (GHG) emissions from groundwater pumping. A landscape that internalizes both non-market ecosystem service benefits and market value from crops has 30% greater social value than a landscape where only market returns or only non-market value is optimized.

Groundwater response to the 2014 pulse flow in the Colorado River Delta

During the March-May 2014 Colorado River Delta pulse flow, approximately 102×106m3 (82,000 acre-feet) of water was released into the channel at Morelos Dam, with additional releases further downstream. The majority of pulse flow water infiltrated and recharged the regional aquifer. Using groundwater-level and microgravity data we mapped the spatial and temporal distribution of changes in aquifer storage associated with pulse flow. Surface-water losses to infiltration were greatest around the Southerly International Boundary, where a lowered groundwater level owing to nearby pumping created increased storage potential as compared to other areas with shallower groundwater. Groundwater levels were elevated for several months after the pulse flow but had largely returned to pre-pulse levels by fall 2014. Elevated groundwater levels in the limitrophe (border) reach extended about 2km to the east around the midway point between the Northerly and Southerly International Boundaries, and about 4km to the east at the southern end. In the southern part of the delta, although total streamflow in the channel was less due to upstream infiltration, augmented deliveries through irrigation canals and possible irrigation return flows created sustained increases in groundwater levels during summer 2014. Results show that elevated groundwater levels and increases in groundwater storage were relatively short lived (confined to calendar year 2014), and that depressed water levels associated with groundwater pumping around San Luis, Arizona and San Luis Rio Colorado, Sonora cause large, unavoidable infiltration losses of in-channel water to groundwater in the vicinity.

Changes of Groundwater Quality in the Sorrounding Pollution Sources Due to Earthquake Dissaster

Groundwater is the main domestic water supply of the population of the Yogyakarta Special Region, both in the urban and as well as in the rural area due to its quantity and quality advantages. The rapid population growth has caused an increase of groundwater demand, consequently it is facing some problems to the sustainability of groundwater supply. Lowering of groundwater level has been observed in some places, as well as the degradation of groundwater quality. Earthquake which stroke Yogyakarta on 27 May 2006, damaged buildings and other infrastructures in the area, including roads and bridges. It might also damage the underground structures such as septic tanks, and pipes underneath the earth surface. It might cause cracking of the geologic structures. Furthermore, the damage of underneath infrastructures might create groundwater quality changes in the area. Some complains of local community on lowering and increasing groundwater level and groundwater quality changes were noted. Field observation and investigation were conducted, including collection of groundwater samples close to (the) pollution sources. Laboratory analyses indicated that some parameters increased to exceed the drinking water quality standards. The high content of Coli form bacteria possibly was caused by contamination of nearby septic tanks or other pollution sources to the observed groundwater in the dug well.

Statistical Approach to River–Aquifer Interaction in the Lower Nakdong River Basin, Republic of Korea

AbstractThe construction of river barrages has led to an increase in groundwater (GW) levels (WL_G) near the upstream regions of these barrages, particularly in the wet season. Statistical approaches were applied in this study to examine the relationships between WL_G and river water (RW) level (WL_R), and electrical conductivity of groundwater (EC_G) and electrical conductivity of river water (EC_R) in the Changnyeong–Haman river barrage area located downstream of the Nakdong River for the period June 2011–January 2014. Our finding suggested that the WL_G increased and the concentrations of most chemical constituents in the GW decreased in the study area owing to the construction of the barrage. However, long‐term operation of the barrage is expected to trigger a decrease in the RW–GW interaction resulting from the clogging of the bed and the wall of the river, which would in turn increase GW contamination. Copyright © 2016 John Wiley & Sons, Ltd.

Mechanism analysis of sinkhole formation at Maohe village, Liuzhou city, Guangxi province, China

In May 2012, a series of ground collapsing events occurred at Maohe village, Liuzhou city, Guangxi province, China during and after a heavy rainfall event. The collapsing incidents resulted in thirty-seven cover collapse sinkholes, eleven donut-shaped subsidence areas and sixty-eight earth fissures. The impact area encompasses more than 40,000 m2. Extensive investigations including land use inventory, advancement of forty-nine exploratory boreholes, and geotechnical and hydrogeological analysis of soil samples were conducted to determine the contributing factors to these sinkhole formations. Because of the heterogeneity in the overburden composition and underling dolomite, the controlling factors may be different for each sinkhole. However, three factors contribute to the scale of the collapsing events: presence of cavities in the underlying bedrock, unique characteristics of overburden materials, and drastic change of groundwater levels. The wide spread cavities in the underlying dolomite make the investigation area inherently vulnerable to ground collapses. The shear strengths of the overburden materials allow for development of soil cavities in the subsurface without skylighting for a long time. The drastic groundwater level increase is the triggering factor and determines the time of the collapses. Higher groundwater levels accelerate the subsurface erosion process and enlargement of soil cavities and cause hydrofracturing and hammer effects on the soils.

Small dams revive dry rivers and mitigate local climate change in India’s drylands

Purpose – This study aims to assess how small check dams built across rivers in India’s drylands can revitalize rivers during dry season and mitigate local climate change consequences. The surface- and groundwater resources are increasingly under pressure throughout India. The imminent climate change consequences will further aggravate the crisis and this paper has addressed this difficult issue. Design/methodology/approach – This study was conducted in India’s dryland districts, namely, Dahod in Gujarat and Jhalawar and Banswara in Rajasthan state, to assess the impacts of small dams. Data on dams, sustainability, groundwater levels and benefits to farmers were systematically collected to analyze advantages offered by check dams with reference to climate change mitigation. Findings – The study shows that 356 check dams built during 1990-2012 across the tribal drylands of India, with a cost of USD 17 million, benefited over one million people from farming communities. The dams also increased groundwater levels in villages, revived rivers during dry season and increased forest growth along rivers, ultimately mitigating local climate change-imposed negative consequences. Research limitations/implications – Data on small dams are limited in India, as public have no access to such data because the work is done mainly by local contractors. Practical implications – The check dams, the role of which is highlighted here, are simple, eco-friendly and cost-effective. If it is adopted across the vast drylands of India and elsewhere, it has the potential to increase agricultural output; guarantee food security; enhance groundwater resources; and, above all, mitigate local climate change consequences. Social implications – If check dams are built in large numbers across India, it has the potential to increase agricultural output; guarantee food security; enhance groundwater resources; and, above all, mitigate climate change. Originality/value – The highlighted results and discussion will guide scientists, politicians and policymakers to make informed decisions to combat India ’ s future climate change consequences.

A simplified method for predicting rainfall-induced mobility of active landslides

This paper deals with the landslides that are reactivated by a groundwater level increase owing to rainfall. These landslides are usually characterized by low displacement rate with deformations essentially concentrated within a narrow shear zone above which the unstable soil mass moves like a rigid body (i.e., with a horizontal displacement profile that is essentially constant with depth). In view of this evidence, a new method based on a simple sliding block model is proposed in the present study for a preliminary evaluation of landslide mobility. Unlike other existing methods that provide an evaluation of landslide mobility on the basis of groundwater level measurements, the present method directly relates landslide movements to rain recordings. This possibility constitutes a significant advantage from a practical viewpoint because it allows future displacement scenarios to be predicted from expected rainfall scenarios. In addition, the present method requires a limited number of parameters as input data, many of which can be obtained from conventional geotechnical tests. To evaluate the other parameters involved, an efficient calibration procedure is also proposed. Four case studies documented in the literature are analyzed to assess the capability of the present method to reproduce the main features of the slope response to rainfall. In all these case studies, both groundwater level variations and landslide displacements observed in field are well approximated by the method.

Environmental state and buffering properties of underground hydrosphere in waste landfill site of the largest petrochemical companies in Europe

The article examines the waste landfill site of PJSC “Nizhnekamskneftekhim” built 1982. Particular attention is paid to the volume of disposed wastes and peculiarities of landfill operation. It has been revealed that the landfill negatively impacts groundwater. The increase in groundwater level and contamination degree is dependent on recharge from infiltration of precipitation that interacts with the waste in the landfill cells. Groundwater contamination follows the longitudinal distribution pattern, with maximum intensity reaching in the nearest area of the landfill. With increasing distance, concentration of all pollutants sharply reduces. Within three kilometers away from the landfill, groundwater turns to its background values indicating its quality. The landfill discharges oil, phenols, formaldehyde, benzol, toluene, xylene, ethylbenzene, and iron and, to a lesser extent, sulfates, chlorides and barium into the underground hydrosphere. The overlimiting concentrations of other components are caused by intensive leaching from the rocks by aggressive carbonic acid water. The concentrations of hydrocarbonates can reach 8 g/l in the groundwater within the landfill and its nearest area, however, under natural conditions, they do not exceed 0.4 g/l. This is only possible in a case of partial activity of carbon dioxide associated with destruction of organic matter disposed in the landfill. One of the processes that play an important role in groundwater quality recovery is mixing of contaminated groundwater with infiltrating precipitation.

Fluoride in weathered rock aquifers of southern India: Managed Aquifer Recharge for mitigation.

Climatic condition, geology, and geochemical processes in an area play a major role on groundwater quality. Impact of these on the fluoride content of groundwater was studied in three regions-part of Nalgonda district in Telangana, Pambar River basin, and Vaniyar River basin in Tamil Nadu, southern India, which experience semi-arid climate and are predominantly made of Precambrian rocks. High concentration of fluoride in groundwater above 4mg/l was recorded. Human exposure dose for fluoride through groundwater was higher in Nalgonda than the other areas. With evaporation and rainfall being one of the major contributors for high fluoride apart from the weathering of fluoriderich minerals from rocks, the effect of increase in groundwater level on fluoride concentration was studied. This study reveals that groundwater in shallow environment of all three regions shows dilution effect due to rainfall recharge. Suitable managed aquifer recharge (MAR) methods can be adopted to dilute the fluoriderich groundwater in such regions which is explained with two case studies. However, in deep groundwater, increase in fluoride concentration with increase in groundwater level due to leaching of fluoriderich salts from the unsaturated zone was observed. Occurrence of fluoride above 1.5mg/l was more in areas with deeper groundwater environment. Hence, practicing MAR in these regions will increase the fluoride content in groundwater and so physical or chemical treatment has to be adopted. This study brought out the fact that MAR cannot be practiced in all regions for dilution of ions in groundwater and that it is essential to analyze the fluctuation in groundwater level and the fluoride content before suggesting it as a suitable solution. Also, this study emphasizes that long-term monitoring of these factors is an important criterion for choosing the recharge areas.

Effects of root mat buoyancy and heterogeneity on floating fen hydrology

AbstractFloating fen ecosystems are home to several protected habitats and species. Their development and conservation require special attention regarding water management. Although they are known to be heterogeneous and partially buoyant, their root mats are simulated in hydrological models as homogeneous, static systems. The objective of this study is to quantify root mat heterogeneity and buoyancy and to assess their effects on groundwater flow and transport, and to determine if these factors need to be taken into account in modelling.We conducted field measurements of root mat heterogeneity and buoyancy in the ‘Nieuwkoopse Plassen’, the Netherlands. We found that hydraulic conductivity varied over four orders of magnitude and negatively correlated with degree of decomposition, resulting in a zonation of high conductivity near the surface and low conductivity in the deeper layers. Also, we found that the root mat moved vertically with the surface water. It became more buoyant with higher temperatures, but less buoyant with increasing groundwater levels relative to the surface.We implemented the findings in a semi‐steady state hydrological model of a floating fen to compare the effects with other parameters. The profound heterogeneity had a limited effect on the water budget, but a clear effect on the flow lines and thus should be taken into account when modelling transport processes in floating fens. Although buoyancy affected the relative groundwater level near the root mat edge, it did not affect the water budget or the flow lines and may therefore be neglected in water budget modelling. Copyright © 2015 John Wiley & Sons, Ltd.

Environmental Hydrogeological Conditions of a Nuclear Power Plant Site in Egypt

The study area is located on the North Western Coast of the Mediterranean Sea which has been selected for establishing a nuclear power plant in Egypt. In this study, the hydrogeological conditions of the site are discussed and evaluated, based on the field survey of soil boring, the piezometers data and the chemical analysis of groundwater samples. The Quaternary aquifer is the main water-bearing layers in the studied area and it is mainly composed of ooltic limestone. Based on the collected geological and hydrogeological data from 18 mointoring wells encountered the Quaternary aquifer with a depth down to 30 m, groundwater fluctuations and groundwater flow maps were constructed. From the records, it is observed that, the groundwater level rises about 2 cm per year. Thus, there is no risk of plant site flooding from increasing groundwater levels, as the thickness of the aeration zone is more than 12 meters. The general groundwater flow in the area of study is from north to south following the main recharge source presneted by the sea water. The depth to water in the area ranges between 2 to 24 meters and it is increasing towards the south. Eighteen water samples are gathered from the available eighteen monitoring wells. The average total salinity ranges from 17193 ppm to 36800 ppm (very saline water) and the pH values vary from 7.5 to 8.5, reflecting slightly alkaline water. The groundwater was classified as mainly saline water, while few samples show a meteoric origin, based on Sulin’s graph. This meteoric water originates from the scares rain events. The evaluation of groundwater shows that, it’s not suitable for irrigation purposes.

Combining groundwater quality analysis and a numerical flow simulation for spatially establishing utilization strategies for groundwater and surface water in the Pingtung Plain

Summary Overexploitation of groundwater is a common problem in the Pingtung Plain area of Taiwan, resulting in substantial drawdown of groundwater levels as well as the occurrence of severe seawater intrusion and land subsidence. Measures need to be taken to preserve these valuable groundwater resources. This study seeks to spatially determine the most suitable locations for the use of surface water on this plain instead of extracting groundwater for drinking, irrigation, and aquaculture purposes based on information obtained by combining groundwater quality analysis and a numerical flow simulation assuming the planning of manmade lakes and reservoirs to the increase of water supply. The multivariate indicator kriging method is first used to estimate occurrence probabilities, and to rank townships as suitable or unsuitable for groundwater utilization according to water quality standards for drinking, irrigation, and aquaculture. A numerical model of groundwater flow (MODFLOW) is adopted to quantify the recovery of groundwater levels in townships after model calibration when groundwater for drinking and agricultural demands has been replaced by surface water. Finally, townships with poor groundwater quality and significant increases in groundwater levels in the Pingtung Plain are prioritized for the groundwater conservation planning based on the combined assessment of groundwater quality and quantity. The results of this study indicate that the integration of groundwater quality analysis and the numerical flow simulation is capable of establishing sound strategies for joint groundwater and surface water use. Six southeastern townships are found to be suitable locations for replacing groundwater with surface water from manmade lakes or reservoirs to meet drinking, irrigation, and aquaculture demands.

Pengaruh Hujan terhadap Perubahan Elevasi Muka Air Tanah pada Model Unit Resapan dengan Media Tanah Pasir

This study aimed to determine changes in ground water level against time to recharge the unit models with medium sand soil in cloudburst conditions, to determine the effect of changes in humidity land in heavy rain conditions and for the efficiency of the model unit catchment .. By using the model infiltration unit made from box 170x170x200 cm3 and infiltration well with dimensions of 30x30x100 cm3 filled with 90 cm thick layer of sandy soil . The results showed that changes in ground water level is 18.8 % , 22.4 % and 24 % for the test I, II, III , respectively .. Soil moisture for the test I ran to saturation at 110 minutes , while for II and III trials in the 90th minute . Unit efficiency filtration models in improving the soil surface water is 3.6 % . This suggests that these filtration units of the model can reduce surface water runoff and increasing groundwater levels.