Estimating surface runoff and groundwater recharge in an urban catchment using a water balance approach

Hydrogeology Journal - Land-use changes often have significant impact on the water cycle, including changing groundwater/surface-water interactions, modifying groundwater recharge zones, and...     

A catchment water balance model for estimating groundwater recharge in arid and semiarid regions of south-east Iran

This paper presents a new model of the rainfall-runoff-groundwater flow processes applicable to semiarid and arid catchments in south-east Iran. The main purpose of the model is to assess the groundwater recharge to aquifers in these catchments. The model takes into account main recharge mechanisms in the region, including subsurface flow in the valley alluvium in mountainous areas and recharge from the bed of ephemeral rivers. It deals with the effects of spatial variation in the hydrological processes by dividing the catchment into regions of broad hydrologic similarity named as highland, intermediate and aquifer areas. The model is based on the concept of routing precipitation within and through the catchment. The model has been applied to the Zahedan catchment and the results indicate that the groundwater level estimated by the recharge model generally is in agreement with the behaviour of groundwater levels in observation wells. The sensitivity analysis indicates that when the rainfall in the aquifer area is used to replace the values recorded in the intermediate area and the highland area, the recharge estimates are reduced by 42-87%. This result supports the division of the catchment into different zones of hydrological similarity to account for spatial variability of hydrological processes. Electronic Publication     

Three-dimensional hydrostratigraphical modelling to support evaluation of recharge and saltwater intrusion in a coastal groundwater system in Vietnam

Saltwater intrusion is generally related to seawater-level rise or induced intrusion due to excessive groundwater extraction in coastal aquifers. However, the hydrogeological heterogeneity of the subsurface plays an important role in (non-)intrusion as well. Local hydrogeological conditions for recharge and saltwater intrusion are studied in a coastal groundwater system in Vietnam where geological formations exhibit highly heterogeneous lithologies. A three-dimensional (3D) hydrostratigraphical solid model of the study area is constructed by way of a recursive classification procedure. The procedure includes a cluster analysis which uses as parameters geological formation, lithological composition, distribution depth and thickness of each lithologically distinctive drilling interval of 47 boreholes, to distinguish and map well-log intervals of similar lithological properties in different geological formations. A 3D hydrostratigraphical fence diagram is then generated from the constructed solid model and is used as a tool to evaluate recharge paths and saltwater intrusion to the groundwater system. Groundwater level and chemistry, and geophysical direct current (DC) resistivity measurements, are used to support the hydrostratigraphical model. Results of this research contribute to the explanation of why the aquifer system of the study area is almost uninfluenced by saltwater intrusion, which is otherwise relatively common in coastal aquifers of Vietnam.     

Estimating groundwater recharge induced by engineering systems in a semiarid area (southeastern Spain)

The scarcity of water resources in semiarid regions is usually accompanied by brief periods of quite intense precipitation that can generate potentially catastrophic floods. In such regions, the use of runoff water for aquifer recharge can contribute to both flooding prevention and effective management of water resources. This paper presents the results of a study undertaken in southeastern Spain focusing on the recharge induced by a number of engineering structures (check dams) and gravel pits. The current network of check dams consists of 107 dams, of which 64 are located over permeable substrates and so we can induce recharge of the storm runoff retained therein. The hydrological model was performed using the curve number method (CN) of the Service for the Conservation of Soils, utilizing code HEC-HMS. Results indicate that the proportion of runoff infiltrated through the check dams varies from 3% to more than 50%, according to the effective volume of water dammed and the substrate. In addition, hydrological modelling was carried out in a subbasin taking advantage of the presence of one of a number of gravel pits. The gravel pits are situated in the apical sectors of alluvial fans that overlie hydrogeological units that are widely overexploited, and so they are well positioned for use for artificial recharge. In this case, we conclude that a pit is capable of retaining and infiltrating the combined runoff volumes for various return periods (5, 25, 50, and 100 years). Furthermore, the simulation carried out suggests that the recharge processes in these environments are intimately linked to episodic storm events. The incorporation of hydrogeological criteria in the design and construction of check dams could therefore be very useful for the optimum management of water resources in semiarid zones.     

Estimating groundwater recharge following land-use change using chloride mass balance of soil profiles: a case study at Guyuan and Xifeng in the Loess Plateau of China

Groundwater recharge is affected by land use in (semi)arid areas. A new application of the chloride-mass-balance approach has been developed to estimate the reduction in groundwater recharge following land-use change by comparing chloride concentrations below the root zone and above the base of the chloride accumulation zone, before and after the land-use conversion. Two sites in the Loess Plateau of central China have been selected for study. Results from the Guyuan terrace region show that groundwater recharge beneath natural sparse small-grass was 100?mm/year, but the conversion to winter wheat about 100?years ago has reduced groundwater recharge to 55?mm/year. At the Xifeng Loess Plain the conversion from winter wheat, with groundwater recharge at 33?mm/year, to apple orchard 7?years ago has led to chloride accumulation to 5?m below land surface, suggesting the recharge rate has been reduced. This is in agreement with previous studies in these areas which have shown that the regional afforestation and other land-use conversions have resulted in deep soil desiccation and have caused an upper boundary to form with low matrix potential, thus preventing the soil moisture from actually recharging the aquifer.     

Impact of climate change on groundwater recharge in a small catchment in the Black Forest, Germany

Temporal and spatial changes of the hydrological cycle are the consequences of climate variations. In addition to changes in surface runoff with possible floods and droughts, climate variations may affect groundwater through alteration of groundwater recharge with consequences for future water management. This study investigates the impact of climate change, according to the Special Report on Emission Scenarios (SRES) A1B, A2 and B1, on groundwater recharge in the catchment area of a fissured aquifer in the Black Forest, Germany, which has sparse groundwater data. The study uses a water-balance model considering a conceptual approach for groundwater-surface water exchange. River discharge data are used for model calibration and validation. The results show temporal and spatial changes in groundwater recharge. Groundwater recharge is progressively reduced for summer during the twenty-first century. The annual sum of groundwater recharge is affected negatively for scenarios A1B and A2. On average, groundwater recharge during the twenty-first century is reduced mainly for the lower parts of the valley and increased for the upper parts of the valley and the crests. The reduced storage of water as snow during winter due to projected higher air temperatures causes an important relative increase in rainfall and, therefore, higher groundwater recharge and river discharge.     

Delineating spring recharge areas in a fractured sandstone aquifer (Luxembourg) based on pesticide mass balance

A simple method to delineate the recharge areas of a series of springs draining a fractured aquifer is presented. Instead of solving the flow and transport equations, the delineation is reformulated as a mass balance problem assigning arable land in proportion to the pesticide mass discharged annually in a spring at minimum total transport cost. The approach was applied to the Luxembourg Sandstone, a fractured-rock aquifer supplying half of the drinking water for Luxembourg, using the herbicide atrazine. Predictions of the recharge areas were most robust in situations of strong competition by neighbouring springs while the catchment boundaries for isolated springs were extremely sensitive to the parameter controlling flow direction. Validation using a different pesticide showed the best agreement with the simplest model used, whereas using historical crop-rotation data and spatially distributed soil-leaching data did not improve predictions. The whole approach presents the advantage of integrating objectively information on land use and pesticide concentration in spring water into the delineation of groundwater recharge zones in a fractured-rock aquifer.     

Application of the water balance model J2000 to estimate groundwater recharge in a semi-arid environment: a case study in the Zarqa River catchment, NW-Jordan

Pollution and overexploitation of scarce groundwater resources is a serious problem in the Zarqa River catchment, Jordan. To estimate this resource’s potential, the amount and spatial distribution of groundwater recharge was calculated by applying the hydrological model J2000. The simulation period is composed of daily values gathered over a 30-year period (July 1977 to June 2007). The figure finally obtained for estimated groundwater recharge of the Zarqa River catchment is 105 × 10⁶ m³ per year (21 mm a^?1). This is 19 % higher than the value previously assumed to be correct by most Jordanian authorities. The average ratio of precipitation to groundwater recharge is 9.5 %. To directly validate modelled groundwater recharge, two independent methods were applied in spring catchments: (1) alteration of stable isotope signatures (δ¹⁸O, δ²H) between precipitation and groundwater and (2) the chloride mass balance method. Recharge rates determined by isotopic investigations are 25 % higher, and recharge rates determined by chloride mass balance are 9 % higher than the modelled results for the corresponding headwater catchments. This suggests a reasonably modelled safe yield estimation of groundwater resources.     

Estimation of groundwater recharge using a GIS-based distributed water balance model in Dire Dawa, Ethiopia

Sustainable groundwater management requires knowledge of recharge. Recharge is also an important parameter in groundwater flow and transport models. Spatial variation in recharge due to distributed land-us.e, soil texture, topography, groundwater level, and hydrometeorological conditions should be accounted for in recharge estimation. However, conventional point-estimates of recharge are not easily extrapolated or regionalized. In this study, a spatially distributed water balance model WetSpass was used to simulate long-term average recharge using land-use, soil texture, topography, and hydrometeorological parameters in Dire Dawa, a semiarid region of Ethiopia. WetSpass is a physically based methodology for estimation of the long-term average spatial distribution of surface runoff, actual evapotranspiration, and groundwater recharge. The long-term temporal and spatial average annual rainfall of 626 mm was distributed as: surface runoff of 126 mm (20%), evapotranspiration of 468 mm (75%), and recharge of 28 mm (5%). This recharge corresponds to 817 l/s for the 920.12 km² study area, which is less than the often-assumed 1,000 l/s recharge for the Dire Dawa groundwater catchment.     

Stochastic groundwater modeling of a sedimentary aquifer: evaluation of the impacts of abstraction scenarios under conditions of reduced recharge

A transient finite difference groundwater flow model has been calibrated for the Nasia sub-catchment of the White Volta Basin. This model has been validated through a stochastic parameter randomization process and used to evaluate the impacts of groundwater abstraction scenarios on resource sustainability in the basin. A total of 1500 equally likely model realizations of the same terrain based on 1500 equally likely combinations of the data of the key aquifer input parameters were calibrated and used for the scenario analysis. This was done to evaluate model non-uniqueness arising from uncertainties in the key aquifer parameters especially hydraulic conductivity and recharge by comparing the realizations and statistically determining the degree to which they differ from each other. Parameter standard deviations, computed from the calibrated data of the key parameters of hydraulic conductivity and recharge, were used as a yardstick for evaluating model non-uniqueness. All model realizations suggest horizontal hydraulic conductivity estimates in the range of 0.03–78.4 m/day, although over 70 % of the area has values in the range of 0.03–14 m/day. Low standard deviations of the horizontal hydraulic conductivity estimates from the 1500 solutions suggest that this range adequately reflects the properties of the material in the terrain. Lateral groundwater inflows and outflows appear to constitute significant components of the groundwater budgets in the terrain, although estimated direct vertical recharge from precipitation amounts to about 7 % of annual precipitation. High potential for groundwater development has been suggested in the simulations, corroborating earlier estimates of groundwater recharge. Simulation of groundwater abstraction scenarios suggests that the domain can sustain abstraction rates of up to 200 % of the current estimated abstraction rates of 12,960 m³/day under the current recharge rates. Decreasing groundwater recharge by 10 % over a 20-year period will not significantly alter the results of this abstraction scenario. However, increasing abstraction rates by 300 % over the period with decreasing recharge by 10 % will lead to drastic drawdowns in the hydraulic head over the entire terrain by up to 6 m and could cause reversals of flow in most parts of the terrain.     

Tidal controls on coastal groundwater conditions: field investigation of a macrotidal system

Previous studies of coastal groundwater resources have not properly explored the hydraulic conditions at coastal and estuarine boundaries, despite recognised influences of oceanic and estuarine water-level fluctuations (e.g. tides and waves) on groundwater near these boundaries. Such influences may have important implications for determining submarine groundwater discharge and seawater intrusion. In this paper, oceanic and estuarine controls on the hydrology of coastal aquifers are characterised for a macrotidal system—the Pioneer Valley coastal plain, northeastern Australia. The tidal water-table over-height (tide-induced increase in average water-table height at the coastline) is quantified at three locations and compared with theoretical estimates, which assume simplified physiographical conditions compared with those encountered at the field sites. The results indicate that local geological conditions, beach morphology and characteristics of tidal forcing control the behaviour of nearshore groundwater within the system. Existing analytical and numerical solutions that are commonly applied as first-pass estimates are found to be insufficient for predicting observed tidal water-table over-height in the Pioneer Valley, due to the sediment heterogeneities, non-uniform beach slopes and large tidal ranges of the system. The study reveals the spatial and temporal variability in tidally influenced hydraulic heads at the estuarine and coastal boundaries of the aquifer, and provides estimates of tidal water-table over-height up to 2.41 m during spring tides. These findings highlight the complexity of coastal groundwater systems, and the need to incorporate appropriate nearshore and near-estuary boundary conditions in models of regional groundwater flow in coastal aquifers.     

Estimating groundwater recharge using GIS-based distributed water balance model in an environmental protection area in the city of Sete Lagoas (MG), Brazil

Improvement in modern water resource management has become increasingly reliant on better characterizing of the spatial variability of groundwater recharge mechanisms. Due to the flexibility and reliability of GIS-based index models, they have become an alternative for mapping and interpreting recharge systems. For this reason, an index model by integrating water balance parameters (surface runoff, actual evapotranspiration, and percolation) calculated by Thornthwaite and Mather’s method, with maps of soil texture, land cover, and terrain slope, was developed for a sustainable use of the groundwater resources. The Serra de Santa Helena Environmental Protection Area, next to the urbanized area of Sete Lagoas (MG), Brazil, was selected as the study area. Rapid economic growth has led to the subsequent expansion of the nearby urban area. Large variability in soil type, land use, and slope in this region resulted in spatially complex relationships between recharge areas. Due to these conditions, the study area was divided into four zones, according to the amount of recharge: high (>?100 mm/year), moderate (50–100 mm/year), low (25–50 mm/year), and incipient (>?25 mm/year). The technique proved to be a viable method to estimate the spatial variability of recharge, especially in areas with little to no in situ data. The success of the tool indicates it can be used for a variety of groundwater resource management applications.     

Estimating groundwater recharge through tills: a sensitivity analysis of soil moisture budgets and till properties in Ireland

The study highlights the dangers of limiting recharge calculations in humid climates to meteorological and soil considerations. It highlights the importance of developing a conceptual understanding of the influence of geology on recharge mechanisms and recharge rates. Uncertainties in recharge estimates through tills are examined by a study of the available literature, combined with sensitivity analyses of soil moisture budget parameters and of hypothetical scenarios of till properties and hydraulic gradients that are realistic for Irish conditions. The sensitivity analyses demonstrate that till properties have a greater influence over recharge than the soil moisture budgeting parameters. Results are considered in terms of recharge coefficients, representing the proportion of effective precipitation that becomes actual recharge to the aquifer. The literature review identifies a range in recharge coefficients from 4% to 90% in selected field and catchment scale studies from bedrock aquifers in Ireland and the U.K. The sensitivity analyses are able to simulate a similar range in recharge coefficient of 2% to 80% by varying only till permeability, thickness and vertical hydraulic gradients. In the scenarios examined, the greatest sensitivity to vertical till permeability lies between 0.001 m/day and 0.01 m/day. The sensitivity to soil moisture budgeting parameters is much less apparent. It is concluded that this is due to the dominance of grassland in Ireland and the relatively wet summers, resulting in the limited development of soil moisture deficits by comparison with some parts of the U.K.

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Résumé Cette étude met en lumière les dangers résultants de la pratique consultant à limiter les calculs de recharge aux données météorologiques ainsi qu’aux considérations liées au sol. Elle met en lumière l’importance de développer des modèles conceptuels comprenant l’influence de la géologie sur les mécanismes de la recharge et les taux de recharge. Les incertitudes sur les estimations de la recharge à travers les argiles sont examinées à travers les données disponibles dans la littérature, combinées avec une analyse de sensibilité des paramètres du bilan hydrique et des scénarios hypothétiques reprenant les propriétés des argiles et les gradients hydrauliques qui sont réalistes dans le contexte irlandais de l’étude. Les analyses de sensibilité démontrent que les propriétés des argiles ont une plus grande influence sur la recharge que les paramètres du bilan hydrique des sols. Les résultats sont considérés en terme de coefficients de recharge, représentant la proportion de précipitation effective qui devient la recharge réelle de l’aquifère. La littérature identifie des coefficients de recharge allant de 4 à 90% sur des terrains sélectionnés à l’échelle de bassins-versants, sur les aquifères de socle en Irlande et au Royaume-Uni. Les analyses de sensibilité sont capables de simuler une variation aussi large de coefficients de recharge, en ne changeant rien que la perméabilité des argiles, leur épaisseur et les gradients hydrauliques verticaux. Dans les scénarios étudiés, la meilleure sensibilité à la perméabilité verticale se situe entre 0.001 et 0.01 m/jour. La sensibilité au bilan hydrique est beaucoup moins apparente. On en conclut que ceci est du à la dominance des prairies en Ireland et aux étés relativement humides, résultant des déficits en eau des sols relativement modérés en comparaison avec certaines zones du Royaume-uni.

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Resumen El estudio resalta los peligros de limitar los cálculos de recarga en climas húmedos a las consideraciones meteorológicas y del suelo. Se destaca la importancia de desarrollar un entendimiento conceptual de la influencia de la geología en los mecanismos de recarga y los ritmos de recarga. Se examinan las incertidumbres en los estimados de recarga a través de tills mediante un estudio de la literatura disponible combinado con análisis de sensibilidad de parámetros de balance de humedad del suelo y de escenarios hipotéticos de las propiedades del till y gradientes hidráulicos que son realistas para condiciones típicas de Irlanda. Los análisis de sensibilidad demuestran que las propiedades del till tienen una influencia más grande en la recarga que los parámetros del balance de humedad del suelo. Se consideran los resultados en términos de coeficientes de recarga, representando la proporción de precipitación efectiva que se convierte en recarga real al acuífero. La revisión de literatura identifica un rango de coeficientes de recarga que varía de 4% a 90% en estudios seleccionados de cuencas y escala de campo realizados en acuíferos de macizo rocoso en Irlanda y el Reino Unido. Los análisis de sensibilidad pueden simular un rango similar en los coeficientes de recarga de 2% a 80% al variar únicamente la permeabilidad del till, el espesor y los gradientes verticales hidráulicos. En los escenarios examinados, la relación de sensibilidad más grande con la permeabilidad vertical del till se encuentra entre 0.001 m/día y 0.01 m/día. La sensibilidad en relación a los parámetros del balance de humedad del suelo es mucho menos aparente. Se concluye que esto se debe a la predominancia de tierras con hierba en Irlanda y los veranos relativamente húmedos, lo que resulta en el desarrollo limitado de déficit de humedad de suelo en comparación con algunas partes del Reino Unido.

     

Hydrogeochemical evolution of confined groundwater in northeastern Osaka Basin,Japan: estimation of confined groundwater flux based on a cation exchange mass balance method

A confined aquifer system has developed in argillaceous marine and freshwater sediments of Pliocene–Holocene age in the northeastern Osaka Basin (NEOB) in central Japan. The shallow groundwater (<100 m) in the system is recharged in a northern hilly to mountainous area with dominantly Ca-HCO₃ type water, which changes as it flows toward the SW to Mg-HCO₃ type and then to Na-HCO₃ type water. Comparison of the chemical and Sr isotopic compositions of the groundwater with those of the bulk and exchangeable components of the underground sediments indicates that elements leached from the sediments contribute negligibly to the NEOB aquifer system. Moreover, model calculations show that contributions of paleo-seawater in the deep horizon and of river water at the surface are not major factors of chemical change of the groundwater. Instead, the zonal pattern of the HCO₃-dominant groundwater is caused by the loss of Ca²⁺ from the water as it is exchanged for Mg²⁺ in clays, followed by loss of Mg + Ca as they are exchanged for Na + K in clays between the Ca-HCO₃ type recharge water and the exchangeable cations in the clay layers, which were initially enriched in Na⁺. Part of this process was reproduced in a chromatographic experiment in which Na type water with high ⁸⁷Sr/⁸⁶Sr was obtained from Mg type water with low ⁸⁷Sr/⁸⁶Sr by passing it through marine clay packed in a column. The flux of recharge water into the confined aquifer system according to this chromatographic model is estimated to be 0.99 mm/day, which is compatible with the average recharge flux to unconfined groundwater in Japan (1 mm/day).     

Participatory groundwater modeling for managed aquifer recharge as a tool for water resources management of a coastal aquifer in Greece

Hydrogeology Journal - A participatory modelling approach is presented for effective groundwater management at the Mediterranean coastal plain of Marathon, Greece. The main objective was to...     

Use of chloride-mass balance and environmental isotopes for evaluation of groundwater recharge in the alluvial aquifer, Wadi Tharad, western Saudi Arabia

Groundwater recharge estimation has become a priority issue for humid and arid regions, especially in regions like Saudi Arabia, where the precipitation varies over space and time as a result of topography and seasonality. Wadi Tharad is a typical arid area in western Saudi Arabia. Within its drainage area of 400 km², the groundwater system shows a graded hydrochemical zonation from the hydrocarbonate in the upper reach to the chloride zone in the lower reach. The saturation index (SI) varies depending on the concentrations of carbonate minerals; the mean for calcite and dolomite is about in equilibrium (e.g., zero value). As halite and gypsum indices are negative, it is undersaturated. Isotopic compositions of H and O in the groundwater show that the groundwater recharge resources are mainly from meteoric water. The chloride-mass balance method was refined to estimate the amount of recharge, which is probably 11% of the effective annual rainfall. These results can be used to improve the accuracy of future groundwater management and development schemes.     

基于现场试验研究的浅层地下水人工回灌影响因素分析

近年来上海工程性地面沉降引起的地面沉降漏斗严重影响了周边地区生命线工程的建设及运营安全,浅层地下水人工回灌技术在工程性地面沉降防治中的应用已受到关注。通过现场试验研究,对浅层地下水人工回灌试验中影响回灌量的各因素,包括回灌井结构、回灌井压力以及回灌井使用时间等进行了分析探讨。     

The use of nitrate, bacteria and fluorescent tracers to characterize groundwater recharge and contamination in a karst catchment, Chongqing, China

The Qingmuguan subterranean river system is located in the suburb of Chongqing, China, and it is the drinking water source that local people downstream rely on. The study aims to provide a scientific basis for groundwater protection in that area, using a hydrogeological framework, tracer tests, hydrological online monitoring, and hydrochemical and microbiological investigation, including heterotrophic plate count (HPC) and the analysis of denitrifying bacteria (DNB) and nitrobacteria (NB). The tracer tests proved simple and direct connections between two important sinkholes and the main springs, and also proved that the underground flows here are fast and turbulent. DNB and NB analyses revealed that the main recharge to the underground river in the dry season is the soil-leached water passing through the fissures of the epikarst, while in the rainy season, it is the surface water flow through sinkholes. The hydrochemical and microbiological data confirmed the notable impact of agriculture and sewage on the spring water quality. In the future, groundwater protection here should focus on targeted vulnerability mapping that yields different protection strategies for different seasons.     

Use of chloride mass balance and tritium data for estimation of groundwater recharge and renewal rate in an unconfined aquifer from North Africa: a case study from Tunisia

The scarcity of surface water resources in arid and semi-arid regions from North African countries contributes to the considerable increase of groundwater exploitation, which leads to the development of hydrogeological studies. However, due to the lack of hydrodynamic data in these regions, these studies focus more and more on the geochemical and environmental isotope techniques to insure a better understanding of the hydrodynamic functioning of subsurface systems. In this study, which interests an important unconfined aquifer in central Tunisia, tritium data and chloride mass balance (CMB) method were applied in order to (1) understand the mode of recharge of this aquifer and (2) obtain a reliable estimation of its recharge amount as well as (3) estimate its annual renewal rate. It has been demonstrated that the shallow groundwaters are classified into two groups according to their tritium contents. The first group includes wells located mainly downstream and highlights the significant role of the post-nuclear lineal recharge through Wadis courses. The second group encloses wells located practically overall the rest of the basin and refers to relatively modern waters originated from areal recharge of present-day rainfall. Based on the CMB method, the recharge to this unconfined aquifer is estimated to 31.7 mm year⁻¹, which corresponds to 10.5% of the total rainfall. The annual renewal rate of groundwater, evaluated based on the tritium contents, is up to 16%.     

基于水化学、同位素特征的济南岩溶地下水补给来源研究

文章利用水化学、2H、18O同位素、87Sr/86Sr比值、13C和14C同位素对济南岩溶地下水补给来源、地热水补给来源进行研究。结果表明,岩溶冷水水化学类型以HCO3-Ca、HCO3·SO4-Ca型为主、地热水以SO4-Ca型为主。在旱季,间接补给区对泉群地下水补给比率在66.00%~73.58%之间,直接补给区仅占到26.42%~34.00%,旱季泉水的主要来源为间接补给区岩溶地下水。地热水受到了更新世以来的降水补给,是不同时期降水补给所形成的混合地下水,接受补给区域应为高程较高的张夏或者炒米店-三山子组地层,补给高程在350~550 m之间。