Modelling surface water-groundwater interactions at the Palas Basin (Turkey) using FREEWAT

Palas Basin is a semi-arid closed basin located in the Central Anatolia region of Turkey. The major economic activity in the basin is agriculture; therefore, both surface water and groundwater are used for irrigation. However, intensive use of water resources threatens the hydrologic sustainability of a lake ecosystem (Tuzla Lake) located in the basin. In this study, we analyzed the relationships between agricultural water uses in the Palas Basin and water flows to the Tuzla Lake using groundwater flow model developed with the FREEWAT platform. The model grid with 250 m x 250 m resolution was created based on the entire watershed. Two hydrostratigraphic units were identified. The source terms defined in the model were rainfall recharge and the sink terms were evapotranspiration and wells. The model was run for one year at steady state conditions. Three scenarios were simulated to understand the effect of groundwater use on the lake hydrology. The first scenario assumed that there was no groundwater abstraction. As the second and third water management scenario, the model was run with 50% less and %50 more groundwater abstraction than that of the reference conditions. The model successfully simulated the direction of groundwater flow and groundwater levels in the basin. Annual groundwater recharge was simulated as 5.27 million m3. Groundwater losses were due to pumping (1.49 million m3/yr), leakance to Değirmen River (2.25 million m3/yr) and seepage to Tuzla Lake (1.53 million m3/yr). Water flows to Tuzla Lake were significantly related to pumping rates. Increasing groundwater pumping rates reduces groundwater flows to Tuzla Lake and lowers lake water levels. No groundwater abstraction and reduction in groundwater pumping rates increase water flows to Tuzla Lake and cause higher water levels. This analysis showed that protection of hydrologic characteristics of Tuzla Lake is only possible with more control on groundwater abstraction.

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3-D numerical modelling of groundwater flow for scenario-based analysis and management

Water SA ◽

10.4314/wsa.v44i2.01 ◽

2018 ◽

Vol 44 (2 April) ◽

Author(s):

Muhammad Usman ◽

Rudolf Liedl ◽

Muhammad Arshad ◽

Christopher Conrad

Keyword(s):

Groundwater Flow ◽

Water Levels ◽

Mitigation Strategies ◽

Groundwater Pumping ◽

Groundwater Abstraction ◽

Management Scenarios ◽

Water Balance Components ◽

Negative Change ◽

A Value ◽

Study Results

In recent years, extensive competition for groundwater use among different consumers has exploited major freshwater aquifers in Pakistan. There is an urgent need for appraisal of this precious resource followed by some mitigation strategies. This modelling study was conducted in the mixed cropping zone of the Punjab, Pakistan. Both remote sensing and secondary data were utilized to achieve objectives of this study. The data related to piezometric water levels, canal gauges, well logs, meteorological and lithological information were collected from Punjab Irrigation Department (PID), Water and Power Development Authority (WAPDA). Groundwater flow models for both steady and transient conditions were set-up using FEFLOW-3D. Water balance components and recharge were estimated using empirical relations and inverse modelling approaches. Both manual and automated approaches were utilized to calibrate the models. Moreover, sensitivity analysis was performed to see the response of model output against different model input parameters. Followed by calibration and validation, the model was run for different management scenarios, including lining of canal sections, minimization of field percolation, and change of groundwater abstraction. The study results show a drop in groundwater levels for almost all scenarios. The highest negative change was observed for the 4th scenario (i.e. 25% increase in groundwater pumping over a 10-year period), with a value of 3.73 m, by ignoring very wet summer and winter seasons. For normal weather conditions, the highest negative change was observed for the 4th scenario with a value of 2.91 m followed by 2.68 m for the 3rd scenario (i.e. 50% reduction in canal seepage and field percolation over a 10-year period). For very wet summer and winter seasons, only one positive change was observed, for the 5th scenario (i.e. 25% decrease in groundwater pumping during 10 years period), with a value of 1.17 m. The changes for all other scenarios were negative. The mitigation strategy may include less groundwater pumping, by supporting cultivation of low delta crops and adjusting cropping patterns considering canal water supplies. It is further suggested to support current modelling results by incorporating more detailed information on cropping and by exploring the effect of climate change.

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Impacts of groundwater extraction on groundwater flow and arsenic distribution in the western Hetao Basin, Inner Mongolia, China

E3S Web of Conferences ◽

10.1051/e3sconf/20199809037 ◽

2019 ◽

Vol 98 ◽

pp. 09037

Author(s):

Zhuo Zhang ◽

Huaming Guo ◽

Weiguang Zhao ◽

Haicheng Weng

Keyword(s):

Surface Water ◽

Groundwater Flow ◽

Flow Direction ◽

Temporal Variations ◽

Water Levels ◽

Labile Organic Matter ◽

Near Surface ◽

Groundwater Levels ◽

Arsenic Distribution ◽

Geochemical Parameters

Temporal variations in water levels are crucial for understanding As behaviour in groundwater systems. Groundwater levels were recorded in irrigation wells in non-irrigation and irrigation seasons. Groundwater samples were collected yearly in irrigation wells from 2014 to 2016 and in a multilevel well from 2015 to 2016 for analysing geochemical parameters. Results showed that groundwater flow direction was reversed due to groundwater pumping. The change of groundwater flow led to the surface water, as a new groundwater recharge source, which flushed the near-surface sediments enriched in soluble components and increased groundwater TDS. The labile organic matter introduced by the surface water recharge fueled dissimilatory reduction of Fe(III) oxides and further increased groundwater As concentration.

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Quantitative investigations of the hydraulic connection between a large reservoir and a buried valley aquifer in southern Alberta

Canadian Geotechnical Journal ◽

10.1139/t05-065 ◽

2005 ◽

Vol 42 (5) ◽

pp. 1461-1473 ◽

Cited By ~ 1

Author(s):

B D Smerdon ◽

C A Mendoza ◽

A M McCann

Keyword(s):

Groundwater Flow ◽

Flow Model ◽

Hydraulic Head ◽

Water Levels ◽

Groundwater Flow Model ◽

Reservoir Level ◽

Hydraulic Connection ◽

Southern Alberta ◽

Approximate Location ◽

Pumping Rates

Quantitative investigations, including two aquifer tests and development of a three-dimensional (3D) groundwater flow model, were required to determine the hydraulic connection between an irrigation reservoir and a buried valley aquifer in southern Alberta. Evidence of seepage was detected in the buried valley aquifer 10 km east of the Pine Coulee reservoir at the onset of filling in 1999, when the reservoir level exceeded an elevation of 1035 m above sea level (a.s.l.). Concern for an increase in the local water table and the creation of artesian conditions in the aquifer prompted this study to determine the approximate location of a seepage window that appeared to be connecting the reservoir and aquifer. Observations of hydraulic head in the aquifer during the pumping tests revealed a barrier boundary when the reservoir level was at an elevation of 1035 m a.s.l. and a recharge boundary condition when the elevation exceeded 1039 m a.s.l. These data were used to calibrate a 3D groundwater flow model, which was needed to determine the hydraulic properties and approximate location of the leakage zone. The quantitative investigation showed that seepage likely occurred through the sideslopes of the flooded coulee, rather than through the low-permeability coulee floor sediments or the embankment dam. Further simulations illustrated the expected seepage rates at various reservoir supply levels and the pumping rates required for relief wells installed in the buried valley aquifer to maintain historic aquifer hydraulic head. A brief postanalysis indicated that the forecasted pumping rates were only 15% lower than have been required to maintain preconstruction water levels in the buried valley aquifer.Key words: dams, seepage analysis, groundwater modelling, buried valley aquifer, pumping test.

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Assessing the Potential Impacts of the Grand Ethiopian Renaissance Dam on Water Resources and Soil Salinity in the Nile Delta, Egypt

Sustainability ◽

10.3390/su11247050 ◽

2019 ◽

Vol 11 (24) ◽

pp. 7050 ◽

Cited By ~ 4

Author(s):

Sherien Abdel Aziz ◽

Martina Zeleňáková ◽

Peter Mésároš ◽

Pavol Purcz ◽

Hany Abd-Elhamid

Keyword(s):

Surface Water ◽

Water Resources ◽

Soil Salinity ◽

Crop Yields ◽

Nile Delta ◽

National Income ◽

Water Levels ◽

Groundwater Levels ◽

Deep Aquifers

Several studies have reported that the construction of the Grand Ethiopian Renaissance Dam (GERD) could have severe effects on the water resources in downstream countries, especially Egypt. These effects include changes in surface water level, groundwater levels in shallow and deep aquifers, saltwater intrusion, and increases in soil salinity, which could affect crop yields. This paper assesses the potential impacts of the GERD on the Nile Delta, Egypt. It includes the effects of reducing surface water levels (SWL) and changing the crop patterns at the groundwater levels (GWL), in addition to the effect of cultivating crops that consume less water on soil salinity. A pilot area is selected in the east of the Nile Delta for the assessment. The results of the study revealed that GWL is directly proportional to SWL. Comparing the case study of 2012, when SWL was reduced by 50%, the GWL decreased from 5.0 m to 2.0 m. After adjustment, the crop patterns from rice to other crops decreased the GWL to 1.30 m. Additionally, the results showed that there is a significant relationship between soil salinity and crop patterns. Soil salinity increased during the cultivation of the Delta with non-rice crops, such as grapes. Salinity increased from 0.45 S/m after 10 years of simulation to 0.48 S/m. This estimation highlights the undesirable effects of the GERD on Egypt’s water resources, soil salinity, crop yields, and national income.

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Groundwater–surface water interaction in inland New South Wales: a scoping study

Water Science & Technology ◽

10.2166/wst.2003.0443 ◽

2003 ◽

Vol 48 (7) ◽

pp. 215-224 ◽

Cited By ~ 18

Author(s):

R. Braaten ◽

G. Gates

Keyword(s):

Surface Water ◽

New South ◽

New South Wales ◽

Groundwater Pumping ◽

Groundwater Levels ◽

Depth Data ◽

Water Interaction ◽

South Wales ◽

Groundwater Surface Water Interaction ◽

Basin Geomorphology

Groundwater and surface water have traditionally been managed separately in New South Wales (NSW). However, where rivers and aquifers are hydraulically connected, groundwater pumping has the potential to deplete streamflow. To highlight the major areas of connection in inland NSW, major streams were overlaid with groundwater depth data and the locations of irrigation bores. A consistent pattern was revealed related to basin geomorphology. The main areas of connection are the mid-sections of the major rivers where alluvial systems are well developed yet still narrow and constricted and groundwater depths are shallow. The mapping was validated and the processes explored by calculating water balances for a connected and disconnected reach in the Murrumbidgee River. These showed that, in highly connected reaches, river losses and/or gains are closely related to groundwater levels.

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Hydrological Characteristics of the Te Hapua Wetland Complex:The Potential Influence of Groundwater Level, Bore Abstraction and Climate Change on Wetland Surface Water Levels

10.26686/wgtn.16973461.v1 ◽

2021 ◽

Author(s):

◽

Craig Wayne Allen

Keyword(s):

Climate Change ◽

Surface Water ◽

Groundwater Level ◽

Hydrological Cycle ◽

Shallow Groundwater ◽

Water Levels ◽

Groundwater Abstraction ◽

Potential Threat ◽

Through Flow ◽

Future Viability

<p>Te Hapua is a complex of small, privately owned wetlands approximately 60 km northwest of Wellington. The wetlands represent a large portion of the region's remaining palustrine swamps, which have been reduced to just 1% of the pre-1900 expanse. Whilst many land owners have opted to protect wetlands on their land with covenants, questions have been raised regarding potential threats stemming from the wider region. Firstly, some regional groundwater level records have shown significant decline in the 10 to 25 years they have been monitored. The reason for this is unclear. Wetlands are commonly associated with groundwater discharge, so a decline in groundwater level could adversely affect wetland water input. Secondly, estimated groundwater resources are currently just 8% allocated, so there is potential for a 92% increase in groundwater abstraction from aquifers that underlie the wetlands. Finally, predictions of future climate change indicate changes in rainfall quantity and intensity. This would likely alter the hydrological cycle, impacting on rainfall dependant ecosystems such as wetlands as well as groundwater recharge. Whilst previous ecological surveys at Te Hapua provide valuable information on biodiversity and ecological threat, there has been no detailed study of the hydrology of the wetlands. An understanding of the relationship between the surface water of the wetlands and the aquifers that underlie the area is important when considering the future viability of the wetlands. This study aims to define the local hydrology and assess the potential threat of 'long term' groundwater level decline, increased groundwater abstraction and predicted climate change. Eleven months of water level data was supplied by Wellington Regional Council for three newly constructed Te Hapua wetland surface water and adjacent shallow groundwater monitoring sites. The data were analysed in terms of their relative water levels and response to rainfall. A basic water balance was calculated using the data from the monitoring sites and a GIS analysis of elevation data mapped the wetlands and their watersheds. A survey of 21 individual wetlands was carried out to gather water quality and water regime data to enable an assessment of wetland class. Historical groundwater level trends and geological records were analysed in the context of potential threat to the wetlands posed by a decline in groundwater level. Climate change predictions for the Kapiti Coast were reviewed and discussed in the context of possible changes to the hydrological cycle and to wetlands. Results from the wetland survey indicated that there are two distinct bands of wetlands at Te Hapua. Fens are found mostly in the eastern band and are more likely to be discharge wetlands, some of which are ephemeral. Swamps are found mostly in the western band and are more likely to be recharge wetlands. Dominant water input to fens is via local rainfall and local through-flow of shallow groundwater, especially from surrounding dunes. The eastern band of wetlands is typified by higher dunes and hence has greater input from shallow groundwater than wetlands in the western band. Dominant water input to swamps is via local rainfall, runoff, and through-flow from the immediate watershed and adjacent wetlands. Overall, the future viability of the Te Hapua wetland complex appears promising. Historical groundwater declines appear to be minimal and show signs of reversing. Abstraction from deep aquifers is not likely to impact on wetland water levels. Climate change is likely to have an impact on the hydrological cycle and may increase pressure on some areas, especially ephemeral wetlands. The effect of climate change on groundwater level is more difficult to forecast, but may lower water level in the long term.</p>

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Applying MODFLOW to wet grassland in-field habitats: a casestudy from the Pevensey Levels, UK

Hydrology and Earth System Sciences ◽

10.5194/hess-7-43-2003 ◽

2003 ◽

Vol 7 (1) ◽

pp. 43-55 ◽

Cited By ~ 7

Author(s):

R. B. Bradford ◽

M. C. Acreman

Keyword(s):

Groundwater Flow ◽

Water Table ◽

Hydrological Regime ◽

Water Levels ◽

Management Technique ◽

Low Permeability ◽

Groundwater Levels ◽

Depth To Water Table ◽

Wet Grasslands ◽

Vertical Leakage

Abstract. Historical drainage improvements have created complex hydrological regimes in many low-lying, wet coastal grassland areas. The manipulation of ditch water levels is a common management technique to maintain important in-stream and in-field habitats in such areas. However, in wet grasslands with low soil conductivities the water table in the centre of each field is not closely coupled to variations in ditch stage. Consequently rainfall and evaporation have a greater influence on the depth to water table and water table fluctuations within each field. In-field micro-topographic variations also lead to subtle variations in the hydrological regime and depth to water table that create a mosaic of different wetness conditions and habitats. The depth, duration, timing and frequency of flooding from accumulated rainfall, surface water and standing groundwater also influence the availability of suitable in-field habitats. Land drainage models are often used for studies of wet grasslands, but tend to be more complex and require more field variables than saturated zone models. This paper applies a 3D groundwater flow model, MODFLOW, to simulate groundwater levels within a single field in a wet coastal grassland underlain by a low permeability sequence and located in the central part of Pevensey Levels, Sussex, UK. At this scale, the influence of vertical leakage and regional groundwater flow within the deeper, more permeable part of the sequence is likely to be small. Whilst available data were not sufficient to attempt a full calibration, it was found that the sequence could be represented as a single, unconfined sequence having uniform hydraulic properties. The model also confirmed that evaporation and rainfall are the dominant components of the water balance. Provided certain information requirements are met, a distributed groundwater model, such as MODFLOW, can benefit situations where greater hydrological detail in space and time is required to represent complex and subtle changes influencing the in-field habitats in wet grasslands with low permeability soils. Keywords: wetlands, hydrology,groundwater, MODFLOW

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ASSESSING GROUNDWATER POTENTIAL USE FOR EXPANDING IRRIGATION IN THE BURITI VERMELHO WATERSHED

Irriga ◽

10.15809/irriga.2015v1n2p81 ◽

2015 ◽

Vol 1 (2) ◽

pp. 81-94 ◽

Cited By ~ 2

Author(s):

Doris Elise Wendt ◽

Lineu Neiva Rodrigues ◽

Roel Dijksma ◽

Jos C Van Dam

Keyword(s):

Surface Water ◽

The Netherlands ◽

Water Balance ◽

Agricultural Production ◽

Groundwater Potential ◽

Water Levels ◽

Groundwater Levels ◽

Management Group ◽

Irrigated Area ◽

Potential Use

ASSESSING GROUNDWATER POTENTIAL USE FOR EXPANDING IRRIGATION IN THE BURITI VERMELHO WATERSHED DORIS ELISE WENDT1; LINEU NEIVA RODRIGUES2; ROEL DIJKSMA3; JOS C VAN DAM4 [1] Wageningen University, the Netherlands. [email protected];2Embrapa Cerrados, BR020, km18, CEP 73310970, Planaltina, DF. [email protected];3 Hydrology and Quantative Water Management Group, Wageningen University, the Netherlands. [email protected];4 Soil Physics and Land Management Group, Wageningen University, the Netherlands. [email protected]; 1 ABSTRACT In Brazil, the increasing middle class has raised food demand substantially. The Brazilian Savannah (Cerrados) is one of the rare places where agriculture can expand and address this new demand without jeopardizing the environment. Cerrados has a strictly divided dry and wet season. The dry season lasts from May to September. This long period contributes to various problems such as water shortages, conflicts and insecure food production. Without irrigation, only two crops can be grown per year in this region. Production suffers with a recurrent drought. Because agricultural production is uncertain, irrigation has an important role in this context, but its expansion is limited by water availability. Water conflicts have already occurred in some watersheds, which may jeopardize agriculture and decrease the livelihood of rural communities. In general, water for irrigation is limited to surface water. Therefore, it is important to investigate alternative sources of water, like groundwater. The purpose of this study is to assess the groundwater potential for expanding the irrigated area in a small-scale catchment (Buriti Vermelho, DF, Brazil). The current water demand was investigated and simulated by an Irrigation Strategies Simulation Model (MSEI). A daily water balance was computed, which quantified catchment storage over time. In addition, groundwater behavior and availability were investigated by recession curve analysis. The irrigated area was changed using two scenarios that showed different effects in both catchment surface water balance and groundwater levels. A decline in groundwater levels is seen in all scenarios one year after the beginning of extra extraction. With time, water levels may decline beyond the natural recovery capacity, which will certainly penalize poorer farmers and result in areas being taken out of agricultural production. Keywords: Base flow Recession, Catchment Hydrology, Hydrogeology, Crop Water Productivity WENDT, D.E.; RODRIGUES, L.N.; DIJKSMA, R.; DAM, J.C. VANAVALIAÇÃO DO POTENCIAL DE USO DA ÁGUA SUBTERRÂNEA PARA EXPANSÃO DA IRRIGAÇÃO NA BACIA DO BURITI VERMELHO 2 RESUMO A demanda por alimentos no Brasil cresceu substancialmente devido, entre outras coisas, ao aumento da classe média. O Cerrado brasileiro é um dos poucos lugares no país onde a agricultura ainda pode expandir e atender a essa nova demanda, sem comprometer o meio ambiente. A região do Cerrado possui duas estações climáticas bem definidas, uma seca e outra chuvosa. O longo período da estação seca, que vai de maio a setembro, contribui para o surgimento de vários problemas, entre eles restrições hídricas, conflitos e insegurança na produção de alimentos. Sem irrigação, apenas dois plantios podem ser feitos por ano. Os cultivos sofrem com os veranicos e a produção é incerta. A irrigação é de fundamental importância nesse contexto, mas sua expansão é limitada pela disponibilidade de água. Em algumas bacias hidrográficas já se observam a ocorrência de conflitos, que podem comprometer a agricultura irrigada e a qualidade de vida das comunidades rurais. De maneira geral, a água para irrigação é de superfície. Desta forma, é importante investigar fontes alternativas de água, com vista ao crescimento da irrigação, tais como a água subterrânea. O Objetivo deste trabalho é avaliar a viabilidade de se utilizar água subterrânea para expandir a agricultura irrigada na bacia hidrográfica do Buriti Vermelho, DF, Brasil. A demanda atual de água foi estimada por meio de um modelo de simulação de estratégias de irrigação (MSEI). Um balanço diário da água no solo foi realizado. O comportamento e a disponibilidade de água subterrânea foram avaliados por meio de uma análise da curva de recessão. Para fins da análise, foram utilizados três cenários de área irrigada, que indicaram diferentes efeitos tanto no perfil do balanço de água no solo quanto no nível do lençol freático. Nos três cenários avaliados, em apenas um ano após a expansão da área irrigada, verificou-se um rebaixamento do lençol freático, que pode atingir níveis abaixo da sua capacidade natural de recuperação. Esse rebaixamento penalizará principalmente os agricultores menores. Em alguns casos haverá necessidade de interromper a produção em algumas áreas. Palavras-chave: Curva de recessão, hidrologia, hidrogeologia, produtividade do uso da água

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A high-resolution global-scale groundwater model

Hydrology and Earth System Sciences ◽

10.5194/hess-19-823-2015 ◽

2015 ◽

Vol 19 (2) ◽

pp. 823-837 ◽

Cited By ~ 66

Author(s):

I. E. M. de Graaf ◽

E. H. Sutanudjaja ◽

L. P. H. van Beek ◽

M. F. P. Bierkens

Keyword(s):

Groundwater Flow ◽

Land Surface ◽

Regional Scale ◽

Unconfined Aquifer ◽

Global Scale ◽

Water Levels ◽

Natural State ◽

Groundwater Model ◽

Groundwater Levels ◽

Aquifer Systems

Abstract. Groundwater is the world's largest accessible source of fresh water. It plays a vital role in satisfying basic needs for drinking water, agriculture and industrial activities. During times of drought groundwater sustains baseflow to rivers and wetlands, thereby supporting ecosystems. Most global-scale hydrological models (GHMs) do not include a groundwater flow component, mainly due to lack of geohydrological data at the global scale. For the simulation of lateral flow and groundwater head dynamics, a realistic physical representation of the groundwater system is needed, especially for GHMs that run at finer resolutions. In this study we present a global-scale groundwater model (run at 6' resolution) using MODFLOW to construct an equilibrium water table at its natural state as the result of long-term climatic forcing. The used aquifer schematization and properties are based on available global data sets of lithology and transmissivities combined with the estimated thickness of an upper, unconfined aquifer. This model is forced with outputs from the land-surface PCRaster Global Water Balance (PCR-GLOBWB) model, specifically net recharge and surface water levels. A sensitivity analysis, in which the model was run with various parameter settings, showed that variation in saturated conductivity has the largest impact on the groundwater levels simulated. Validation with observed groundwater heads showed that groundwater heads are reasonably well simulated for many regions of the world, especially for sediment basins (R2 = 0.95). The simulated regional-scale groundwater patterns and flow paths demonstrate the relevance of lateral groundwater flow in GHMs. Inter-basin groundwater flows can be a significant part of a basin's water budget and help to sustain river baseflows, especially during droughts. Also, water availability of larger aquifer systems can be positively affected by additional recharge from inter-basin groundwater flows.

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REAKCJA WÓD POWIERZCHNIOWYCH I PODZIEMNYCH NA OPADY W ZLEWNI RÓŻANEGO STRUMIENIA

Badania Fizjograficzne nad Polska Zachodnia ◽

10.14746/bfg.2019.10.1 ◽

1970 ◽

pp. 7-19

Author(s):

ALEKSANDRA CZUCHAJ ◽

FILIP WOLNY ◽

MAREK MARCINIAK

Keyword(s):

Time Series ◽

Surface Water ◽

Water Level ◽

Correlation Coefficient ◽

Groundwater Level ◽

Water Levels ◽

Groundwater Levels

The aim of the presented research was to analyze the relation between three variables: the daily sum of precipitation, the surface water level and the groundwater level in the Różany Strumień basin located in Poznań, Poland. The correlation coefficient for the subsequent lags for each pair of variables time series has been calculated. The delay with which waters of the basin respond to precipitation varies significantly. Generally, stronger response to rainfall is observed for surface water levels as opposed to groundwater levels.

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