Research on groundwater ecological environment mapping based on ecological service function:A case study of five Central Asian countries and neighboring regions of China

The groundwater system is a unique ecosystem that serves both resource and ecological functions.Hydrogeologists have conducted extensive theoretical research and practical work on groundwater ecological mapping.This paper,based on the study of groundwater resources and surface ecology in the five Central Asian countries and adjacent areas of China,introduces the concept of ecosystem service functions.It establishes a groundwater ecological zoning index system and conducts research of ecological mapping using the five Central Asian countries and adjacent areas of China as examples.Through this process,the ecosystem service functions of groundwater can be more comprehensively reflected,which can better guide regional geological environment protection and industrial planning.This approach helps coordinate the relationship between socio-economic development and water resource protection,maintain the health of the groundwater ecological environment,enhance the value of groundwater ecological services,and promote the sustainable development of regional economies and societies.

Geogenic Pollution of Groundwater Quality in Gampaha District, Sri Lanka: A Case Study of Groundwater Acidification from Rathupaswala

Over recent decades, Gampaha district, Sri Lanka, has experienced significant urbanisation and industrial growth, increasing groundwater demand due to limited and polluted surface water resources. In 2013, a community uprising in Rathupaswala, a village in Gampaha district, accused a latex glove manufacturing factory of causing groundwater acidity (pH < 4). This study evaluates the spatial and temporal changes in geochemical parameters across three transects in the southern part of Gampaha district to 1) assess the impact of geological formations on groundwater;2) compare temporal variations in groundwater;and 3) explain acidification via a geochemical model. Seventy-two sample locations were tested for pH, electrical conductivity (EC), and anion concentrations (sulphate, nitrate, chloride and fluoride). Depth to the water table and distance from the sea were measured to study variations across sandy, peaty, lateritic, and crystalline aquifers. Results showed pH readings around 7 for sandy and crystalline aquifers, below 7 for peaty aquifers, and below 5 for lateritic aquifers, with significant water table fluctuations near Rathupaswala area. Principal component analysis revealed three principal components (PCs) explaining 86.0% of the variance. PC1 (40.6%) correlated with pH, EC, and sulphate (saltwater intrusion), while PC2 (32.0%) correlated with nitrates and depth to the water table (anthropogenic nutrient pollution). A geochemical transport model indicated a cone of depression recharged by acidic groundwater from peat-soil aquifers, leading to acidic groundwater in Rathupaswala area. Previous attributions of acidic pH to the over-exploitation of groundwater by the latex factory have been reevaluated;the results suggest natural acidification from prolonged water-rock interactions with iron-rich lateritic aquifers. Groundwater pH is influenced by local climate, geology, topography, and drainage systems. It is recommended that similar water-rock interaction conditions may be present throughout the wet zone of Sri Lanka, warranting detailed studies to confirm this hypothesis.

Groundwater and environmental challenges in Asia

Asia stands out as the most populous and geographically diverse region globally.The pressing issues of water resource development and the resulting ecological impacts are exacerbated by the region's rapid population growth and economic expansion.Groundwater,a vital source of water in Asia,faces significant disparities in distribution and suffers from unsustainable exploitation practices.This study applies groundwater system theory and categorizes Asia into 11 primary groundwater systems and 36 secondary ones,based on intercontinental geological structures,climate,terrain,and hydrogeological characteristics.As of the end of 2010,Asia's assessed groundwater resources totalled 4.677×10^(9) m^(3)/a,with exploitable resources amounting to 3.274×10^(9) m^(3)/a.By considering the geological environmental impacts of groundwater development and the distinctive characteristics of terrain and landforms,six categories of effect zones with varying distribution patterns are identified.The current research on Asia's groundwater resources,environmental dynamics,and human impacts aims to provide a theoretical foundation for sustainable groundwater management and environmental conservation in the region.

Clogging caused by coupled grain migration and compaction effect during groundwater recharge for unconsolidated sandstone reservoir in groundwater-source heat pump

In unconsolidated sandstone reservoirs,presence of numerous movable grains and a complex grain size composition necessitates a clear understanding of the physical clogging process for effective groundwater recharge in groundwater-source heat pump systems.To investigate this,a series of seepage experiments was conducted under in situ stress conditions using unconsolidated sandstone samples with varying grain compositions.The clogging phenomenon arises from the combined effects of grain migration and compaction,wherein the migration of both original and secondary crushed fine-grain particles blocks the seepage channels.Notably,grain composition influences the migration and transport properties of the grains.For samples composed of smaller grains,the apparent permeability demonstrates a transition from stability to decrease.In contrast,samples with larger grains experience a skip at the stability stage and directly enter the decrease stage,with a minor exception of a slight increase observed.Furthermore,a unique failure mode characterized by diameter shrinkage in the upper part of the sample is observed due to the combined effects of grain migration and in situ stress-induced compaction.These testing results contribute to a better understanding of the clogging mechanism caused by the coupled effects of grain migration and compaction during groundwater recharge in unconsolidated sandstone reservoirs used in groundwater-source heat pump systems.

The Damaging Effects of Abstracting the Deep Aquifers’Groundwater in Jordan-Quality Constraints

The deep aquifers in Jordan contain non-renewable and fossil groundwater and their extraction is quasi a mining process, which ends in the depletion of these resources. Although aquifers in the majority of groundwater basins in Jordan are vertically and horizontally interconnected stratification in different water quality horizons with generally increasing water salinity with the depth is observed. Many officials and planners advocate the extraction of deep salty and brackish water to be desalinated and used in household, industrial, and agricultural uses. In this article, the quality of the groundwater in the different deep aquifers and areas in Jordan is discussed. The results of this study show that the consequences of the deep groundwater exploitation are not restricted to depletion of the deep aquifers but also that the overlying fresh groundwater will, due to vertical and horizontal interconnectedness of the different aquifers, percolate down to replace the extracted deep groundwater. This will cause the down-percolating fresh groundwater to become salinized in the deep saline aquifers, which means that extracting the deep brackish and saline groundwater is not only an emptying process of the deep groundwater but also it is an emptying process of the fresh groundwater overlying them. The results allow to conclude that any extraction of the deep groundwater in areas lying to the north of Ras en Naqab Escarpment will have damaging impacts on the fresh groundwater in the overlying fresh groundwater aquifers. This article strongly advises not to extract the deep brackish and saline groundwater, but to conserve that groundwater as a base supporting the overlying fresh groundwater resources, and that will help in protecting the thermal mineralized water springs used in spas originating from these deep aquifers. The increasing water needs of the country can be covered by the desalination of seawater at Aqaba, which is the only viable option for Jordan at present and in the coming decades.

基于系统药理学结合LC-MS/MS技术探讨温性经筋通贴膏治疗类风湿性关节炎的药效物质基础与作用特点

目的通过液相色谱-质谱-质谱联用(LC-MS/MS)技术结合系统药理学研究温性经筋通贴膏治疗类风湿性关节炎的药效物质基础与作用特点。方法通过LC-MS/MS技术结合文献检索获取温性经筋通贴膏活性成分信息,使用Swiss Target Prediction平台进行作用靶点预测;利用GeneCards、DrugBank和OMIM数据库检索与类风湿性关节炎相关的疾病靶点并与活性成分作用靶点进行映射取交集,通过Cytoscape软件构建“活性成分-有效靶点”网络;将共同靶点导入STRING数据库构建蛋白互作网络;应用Metascape数据库进行GO功能及KEGG通路富集分析;采用AutoDock软件进行关键成分与有效靶点的分子对接研究。结果通过应用LC-MS/MS技术从温性经筋通贴膏中共鉴别出142个活性成分,经检索相关文献补充活性成分至174个,与类风湿性关节炎交集靶点175个;预测温性经筋通贴膏可能通过小檗碱、新补骨脂异黄酮、盐酸巴马汀等主要成分,作用于TNF、IL6、AKT1等关键靶点,调控PI3K/Akt1、JAK/STAT、MAPK等信号通路发挥免疫调节与抗炎镇痛作用;在1152组分子对接验证中,结合能小于-5.0 kcal·mol^(-1)的占94%、小于-7.0 kcal·mol^(-1)的占51%,表明所筛选的潜在活性成分与核心靶点之间具有较好的结合亲和力。结论该研究预测了温性经筋通贴膏治疗类风湿性关节炎的药效物质基础与作用特点,为进一步启发其临床应用及质量控制提供了理论基础。

基于LC-MS/MS测定人体类固醇激素的研究进展

类固醇激素是一类具有环戊烷多氢菲结构的化合物,由细胞色素P450酶催化形成,在调节机体代谢、促进性器官发育等方面起着重要作用。临床上将类固醇激素水平作为肾上腺疾病、精神类疾病等的诊断指标。液相色谱-串联质谱(LC-MS/MS)联用技术因具有高灵敏度、高通量和高专属性的特点,已成为类固醇临床测定的首选方法。本文综述了LC-MS/MS在内源性类固醇激素测定中的应用,特别是在样品前处理、色谱条件和质谱条件优化等方面的研究进展,为临床上类固醇激素的诊断检测提供参考。

LC-MS/MS法同时测定活血止痛胶囊/片中16种真菌毒素及污染状况分析

目的 建立LC-MS/MS法同时测定活血止痛胶囊/片中黄曲霉毒素B_(1)、B_(2)、G_(1)、G_(2)、M_(1)、M_(2),伏马毒素B_(1)、B_(2)、B_(3),赭曲霉毒素A,玉米赤霉烯酮,脱氧雪腐镰刀菌烯醇,T-2毒素,HT-2毒素,桔青霉毒素,杂色曲霉毒素的含量,并对其污染状况进行分析。方法 以亲水-亲脂HLB固相萃取柱净化作为前处理方式,分析采用Agilent RRHD Eclipse Plus C_(18)色谱柱(2.1 mm×50 mm, 1.8μm);流动相乙腈-水(0.1%甲酸-2 mmol/L甲酸铵),梯度洗脱;体积流量0.3 mL/min;柱温35℃;电喷雾电离源(ESI),正负离子模式,动态多反应离子检测(DMRM)模式。结果 16种真菌毒素在各自范围内线性关系良好(R^(2)>0.999 2),平均加样回收率81.7%~118.0%,RSD 0.9%~13.1%。40批样品中检出黄曲霉毒素B_(1)、G_(1),伏马毒素B_(1)、B_(2),赭曲霉毒素A,杂色曲霉毒素,检出率分别为20%、32.5%、57.5%、25%、42.5%、27.5%,其中黄曲霉毒素B_(1)含量最高,为10.26μg/kg。结论 活血止痛制剂中真菌毒素残留较严重,对人体产生危害的潜在风险较高。

平衡透析结合LC-MS/MS法测定大鼠血浆中游离SN-38浓度及其药代动力学应用

目的 建立大鼠血浆中游离SN-38浓度的LC-MS/MS检测方法。方法 采用平衡透析法模拟SN-38在人体内与血浆蛋白结合的过程,在透析完成后分离出游离SN-38,以[2H5]SN-38为内标,用蛋白沉淀法预处理透析液侧(F侧)样品,取上清液进行LC-MS/MS分析;总SN-38及透析后血浆侧(T侧)SN-38样品的预处理方法与游离SN-38相同;分别考察两种方法的专属性、线性关系、精密度、准确度、提取回收率、基质效应、稳定性。结果F侧SN-38在0.04~80 ng·mL^(-1)内与峰面积线性关系良好(r> 0.99);提取回收率为98.6%~101.6%,基质效应为96.2%~97.2%;日内、日间RSD均<15%,且分别在不同条件下稳定性良好。大鼠血浆样品中的总SN-38在0.5~1000 ng·mL^(-1)内与峰面积线性关系良好(r> 0.99);提取回收率为97.3%~99.5%,基质效应为100.5%~101.2%;日内、日间RSD均<15%,且分别在不同条件下稳定性良好。结论 该方法简单易行、准确、灵敏、专属性好,适用于大鼠血浆中游离SN-38浓度的测定。

基于LC-MS/MS的鹿角方中红景天苷在慢性心力衰竭大鼠心肌组织中的分布

目的分析鹿角方中红景天苷在慢性心力衰竭大鼠心肌组织中的分布。方法45只SPF级雄性Wistar大鼠,6~8周龄,采用简单随机抽样法选取8只作为假手术组,假手术组大鼠只暴露腹主动脉不结扎;其余大鼠行腹主动脉缩窄手术,以血管结扎处明显缩窄示手术成功,术后将存活的32只模型大鼠按体重进行区组随机分组,分为模型组(n=8)、鹿角方低剂量组(1.100 g/kg,n=8)、鹿角方中剂量组(2.200 g/kg,n=8)、鹿角方高剂量组(4.400 g/kg,n=8),药物灌胃干预30周。末次灌胃给药2 h后麻醉大鼠,腹主动脉取血,采集心肌组织,LC-MS/MS法分析不同剂量鹿角方组红景天苷在大鼠左、右心室壁的分布。结果红景天苷在1.195~1195.000 ng/ml范围内线性关系良好(r>0.999),精密度RSD%<15%,准确度为90.817%~106.500%,相对回收率为95.222%~100.814%,基质效应RSD%<15%,样品冰浴放置1 h、前处理后室温放置6 h及自动进样器放置48 h内红景天苷的稳定性良好。红景天苷在右心室壁含量与给药剂量线性拟合值R2为0.983,在中、高剂量鹿角方组中红景天苷在左心室壁的含量分别为右心室壁含量的(47.383±12.156)%、(43.805±9.644)%。结论建立的分析方法具有可行性,红景天苷在慢性心力衰竭大鼠左、右心室分布存在差异。

LC-MS/MS法测定大鼠血浆中S,S,S-三丁基三硫代磷酸酯质量浓度及其毒物动力学研究

目的 建立LC-MS/MS法测定大鼠血浆中S,S,S-三丁基三硫代磷酸酯的质量浓度,并用于大鼠体内的毒物动力学研究。方法 采用沉淀蛋白法进行血浆样品前处理,以丙酸倍氯米松为内标。色谱柱为Agilent Zorbax SB C_(18)(50 mm×2.1 mm, 3.5μm)柱,流动相为水(含体积分数0.1%甲酸)-乙腈/甲醇(体积比1∶1),梯度洗脱,流速为0.8 mL·min^(-1)。质谱检测采用ESI源,正离子化方式,多反应监测模式(MRM)进行扫描检测。结果 血浆中S,S,S-三丁基三硫代磷酸酯线性范围为2~800μg·L^(-1),线性良好(r≥0.99),批内、批间RSD均在±15%内,准确度在85%~115%内。高、中、低质量浓度总体提取回收率为89.0%,变异系数为1.1%。结论 本方法适用于大鼠血浆中S,S,S-三丁基三硫代磷酸酯质量浓度的准确测定和动力学研究。

Groundwater recharge via precipitation in the Badain Jaran Desert,China

Precipitation infiltration serves as a significant source of groundwater in the Badain Jaran Desert.To investigate variations in precipitation infiltration within the desert,this study collected data on moisture content and temperature from the vadose zone through in-situ field monitoring.Utilizing these data,a numerical model is employed to explore the mechanism of groundwater recharge via precipitation.The results are as follows:(1)Moisture content and temperature in the shallow vadose zone exhibit significant seasonal variations,with moisture content diminishing with increasing depth;(2)Groundwater recharge via precipitation infiltration initially increases and then decreases with groundwater level depth(GWD).Peak groundwater recharge via precipitation occurs at a GWD of 0.75 m,decreasing to merely 0.012 cm at GWDs exceeding 2 m;(3)Groundwater is no longer susceptible to phreatic water evaporation when the GWD reaches approximately 3.7 m.Therefore,GWD plays a crucial role in governing groundwater recharge via precipitation in the Badain Jaran Desert.

LC-MS/MS法测定鲤鱼中苦参碱和氧化苦参碱

建立基于前处理技术结合液相色谱-串联质谱法(liquid chromatography-tandem mass spectrometry,LC-MS/MS)对鲤鱼基质中苦参碱和氧化苦参碱残留量测定的分析方法.样品采用乙腈均质提取的萃取方式,用硫酸钠作为除水剂,样品经过C18色谱柱分离,以水-乙腈为流动相,基质匹配标准曲线外标法定量.苦参碱和氧化苦参碱在质量浓度范围1—50 ng·mL^(−1)内,具有良好的线性关系,相关系数R^(2)均大于0.99.苦参碱方法检出限为0.21 ng·mL^(−1),定量限为0.69 ng·mL^(−1);氧化苦参碱方法检出限为0.17 ng·mL^(−1),定量限为0.52 ng·mL^(−1).添加浓度水平1.0、2.0、5.0 ng·mL^(−1),平均回收率为72.5%—108.7%,相对标准偏差(relative standard deviation,RSD,n=6)为4.2%—8.2%.苦参碱和氧化苦参碱的基质效应均表现为抑制.该方法前处理方法简单,灵敏度高,稳定性好,适合鲤鱼基质苦参碱和氧化苦参碱残留量的测定,同时为后续同类样品检测提供参考,也为今后相关标准制定提供数据积累.

缬沙坦类药物中相关杂质的LC-MS/MS测定

采用L C-M S/M S方法建立了缬沙坦类药物中相关杂质的测定,使用Discovery^(®)HS F5,(5μm particle size,L×I.D.15 cm×4.6 mm)色谱柱,流动相A为0.1%甲酸水溶液;流动相B为0.1%甲酸甲醇溶液,梯度洗脱,流速为0.40 mL/min,离子化模式为:ESI+,多反应监测模式(MRM)进行定性分析;基质外标法进行定量分析,得到缬沙坦类药物中相关杂质的检出限为10.0μg/kg;定量限为20.0μg/kg,在线性浓度范围为10~100μg/L之间有良好的线性关系相关系数均大于0.999,加标回收率为72.3%~86.9%,相对标准偏差(RSD)为4.7%~8.9%。本方法对于缬沙坦类药物中有关物质的检测分析结果准确率高,可靠性强,适合检测缬沙坦类药物中有关物质的残留量。

Evaluation and Prediction of Groundwater Quality in the Municipality of Za-Kpota (South Benin) Using Machine Learning and Remote Sensing

Accessing drinking water is a global issue. This study aims to contribute to the assessment of groundwater quality in the municipality of Za-Kpota (southern Benin) using remote sensing and Machine Learning. The methodological approach used consisted in linking groundwater physico-chemical parameter data collected in the field and in the laboratory using AFNOR 1994 standardized methods to satellite data (Landsat) in order to sketch out a groundwater quality prediction model. The data was processed using QGis (Semi-Automatic Plugin: SCP) and Python (Jupyter Netebook: Prediction) softwares. The results of water analysis from the sampled wells and boreholes indicated that most of the water is acidic (pH varying between 5.59 and 7.83). The water was moderately mineralized, with conductivity values of less than 1500 μs/cm overall (59 µS/cm to 1344 µS/cm), with high concentrations of nitrates and phosphates in places. The dynamics of groundwater quality in the municipality of Za-Kpota between 2008 and 2022 are also marked by a regression in land use units (a regression in vegetation and marshland formation in favor of built-up areas, bare soil, crops and fallow land) revealed by the diachronic analysis of satellite images from 2008, 2013, 2018 and 2022. Surveys of local residents revealed the use of herbicides and pesticides in agricultural fields, which are the main drivers contributing to the groundwater quality deterioration observed in the study area. Field surveys revealed the use of herbicides and pesticides in agricultural fields, which are factors contributing to the deterioration in groundwater quality observed in the study area. The results of the groundwater quality prediction models (ANN, RF and LR) developed led to the conclusion that the model based on Artificial Neural Networks (ANN: R2 = 0.97 and RMSE = 0) is the best for groundwater quality changes modelling in the Za-Kpota municipality.

Investigation of Groundwater Quality with Borehole Depth in the Basin Granitoids of the Ashanti Region of Ghana

The dependence of groundwater quality on borehole depth is usually debatable in groundwater studies, especially in complex geological formations where aquifer characteristics vary spatially with depth. This study therefore seeks to investigate the relationship between borehole depth and groundwater quality across the granitoid aquifers within the Birimian Supergroup in the Ashanti Region. Physicochemical analysis records of groundwater quality data were collected from 23 boreholes of public and private institutions in the Ashanti Region of Ghana, and the parametric values of iron, fluoride, total hardness, pH, nitrate, and nitrite were used to study the groundwater quality-depth relationship. The results showed that the depth-to-groundwater quality indicated a marginal increase in water quality in the range of 30 to 50 m, which is mathematically represented by the low-value correlation coefficient (r2 = 0.026). A relatively significant increase occurs in the depth range of 50 to 80 m, which is given by a correlation coefficient of r2 = 0.298. The mean percent parameter compatibility was 74%, 82%, 89%, and 97% at 50, 60, 70, and 80 m depths, respectively. The variations in groundwater quality per depth ratio ranged from 1.48, 1.37, 1.27, and 1.21 for 50, 60, 70, and 80 m depth, respectively. The recommended minimum borehole depth for excellent groundwater quality is suggested with a compatibility per meter depth ratio of 1.37. This results in a range between 50 and 70 m as the most desirable drilling depth for excellent groundwater quality within the granitoids of the Birimian Supergroup of the Ashanti Region in Ghana.

Integrated Geological and Geophysical Mapping for Groundwater Potential Studies at Ekwegbe-Agu and Environs, Enugu State, Nigeria

The study integrates both the geological and geophysical mapping techniques for groundwater potential studies at Ekwegbe-Agu and the environs, Enugu state, Nigeria for optimal citing of borehole. Located in the Anambra Basin between latitudes 6˚43'N and 6˚47'N and longitudes 7˚28'E and 7˚32'E, it is stratigraphycally underlain by, from bottom to top, the Enugu/Nkporo, Mamu and Ajali Formation respectively, a complex geology that make citing of productive borehole in the area problematic leading to borehole failure and dry holes due to inadequate sampling. The study adopted a field and analytic sampling approach, integrating field geological, electrical resistivity and self-potential methods. The software, SedLog v3.1, InterpexIx1Dv.3, and Surfer v10 were employed for the data integration and interpretation. The result of the geological field and borehole data shows 11 sedimentary facies consisting of sandstone, shales and heterolith of sandstone/shale, with the aquifer zone mostly prevalent in the more porous sand-dominated horizons. Mostly the AK and HK were the dominant curve types. An average of 6 geo-electric layers were delineated across all transects with resistivity values ranging from 25.42 - 105.85 Ωm, 186.38 - 3383.3 Ωm, and 2992 - 6286.4 Ωm in the Enugu, Mamu and Ajali Formations respectively. The resistivity of the main aquifer layer ranges from 1 to 500 Ωm. The aquifer thickness within the study area varies between 95 and 140 m. The western and northwestern part of the study area which is underlain mainly by the Ajali Formation showed the highest groundwater potential in the area and suitable for citing productive boreholes.

Isotope Tracking of Surface Water Groundwater Interaction in the Beninese Part of the Iullemeden Aquifer System

The Kandi basin is located in northeast Benin (West Africa). This study is focused on the estimation of water fluxes exchanged between the river Niger (and its tributaries) and the transboundary Iullemeden Aquifer System. In that framework, an innovative approach based on the application of the Bayesian Mixing Model (MixSIAR) analysis on water isotopes (oxygen-18, deuterium and tritium) was performed. Moreover, to assess the relevance of the model outputs, Pearson’s correlation and Principal Component Analysis (PCA) have been done. A complex relationship between surface water and groundwater has been found. Sixty percent (60%) of groundwater samples are made of more than 70% river water and rainwater;while 31.25% of surface water samples are made of about 84% groundwater. To safeguard sustainable water resources for the well-being of the local communities, surface water and groundwater must be managed as a unique component in the Kandi basin.

基于LC-MS/MS技术的水蛭配方颗粒中7种碱基和核苷成分分析方法的建立

本文建立了一种使用岛津超高效液相色谱仪Nexera X2和三重四极杆质谱仪LCMS-8050联用测定水蛭配方颗粒中7种碱基和核苷成分的分析方法.水蛭配方颗粒以10%甲醇50℃超声提取30 min,MRM正负模式同时检测.以Discovery■HS F5-3色谱柱进行分离,流动相为0.15%甲酸水溶液和甲醇,10 min内完成梯度洗脱.本方法采用外标法定量,7种化合物在相应的浓度范围内线性关系良好,判定系数(R^(2))均大于0.996,定量限在0.42—3.94μg·g^(-1)之间. 10 ng·mL^(-1)的混合标准品溶液连续进样6次,待测化合物峰面积RSD均小于6%,精密度良好.平行6份加标回收试验,7种化合物平均回收率在87.09%—105.81%之间,RSD%在1.35%—4.70%之间.残留实验结果为阴性.该方法准确可靠,可为水蛭配方颗粒的质量控制提供参考依据.

Pumping-induced Well Hydraulics and Groundwater Budget in a Leaky Aquifer System with Vertical Heterogeneity in Aquitard Hydraulic Properties

In groundwater hydrology,aquitard heterogeneity is often less considered compared to aquifers,despite its significant impact on groundwater hydraulics and groundwater resources evaluation.A semi-analytical solution is derived for pumping-induced well hydraulics and groundwater budget with consideration of vertical heterogeneity in aquitard hydraulic conductivity(K)and specific storage(S_(s)).The proposed new solution is innovative in its partitioning of the aquitard into multiple homogeneous sub-layers to enable consideration of various forms of vertically heterogeneous K or S_(s).Two scenarios of analytical investigations are explored:one is the presence of aquitard interlayers with distinct K or S_(s) values,a common field-scale occurrence;another is an exponentially depth-decaying aquitard S_(s),a regional-scale phenomenon supported by statistical analysis.Analytical investigations reveal that a low-K interlayer can significantly increase aquifer drawdown and enhance aquifer/aquitard depletion;a high-S_(s) interlayer can noticeably reduce aquifer drawdown and increase aquitard depletion.Locations of low-K or high-S_(s) interlayers also significantly impact well hydraulics and groundwater budget.In the context of an exponentially depth-decaying aquitard S_(s),a larger decay exponent can enhance aquifer drawdown.When using current models with a vertically homogeneous aquitard,half the sum of the geometric and harmonic means of exponentially depth-decaying aquitard S_(s) should be used to calculate aquitard depletion and unconfined aquifer leakage.