The\u00a0study highlights the\u00a0institutional framework and the\u00a0roles of\u00a0key organizations \u2013 such as the\u00a0Czech Hydrometeorological Institute (CHMI), river basin\u00a0management authorities, and the\u00a0T. G. Masaryk Water Research Institute \u2013 in\u00a0groundwater monitoring and data interpretation. A\u00a0particular focus is placed on hydrogeological zoning as a\u00a0key tool for spatial and balance assessments, including its historical development and relation to groundwater body delineation under the\u00a0EU Water Framework Directive.<\/span><\/p>\n The\u00a0core of\u00a0the\u00a0analysis is dedicated to four Upper Cretaceous hydrogeological zones (HGR\u00a04410, 4430, 4522, and 4523) that have been consistently assessed as balance-stressed between 2007 and 2023. Long-term comparisons of\u00a0base flow and abstraction data indicate a\u00a0convergence trend, primarily due to declining natural recharge under changing climatic conditions. In\u00a0some zones (especially HGR\u00a04522 and 4523), excessive abstraction has contributed to negative impacts on surface water bodies, including seasonal drying, prompting regulatory responses such as reduced abstraction limits, regime-based monitoring, and mitigation measures.<\/span><\/p>\n The\u00a0article draws on results from several ongoing research projects funded by the\u00a0Technology Agency of\u00a0the\u00a0Czech Republic (e.g., no.\u00a0SS06010268, no.\u00a0SQ01010176, no.\u00a0S02030027, and no.\u00a0SS01010208), focusing on drought impacts, and improved delineation of\u00a0hydrogeological zones, groundwater-surface water interactions, groundwater resource enhancement, and vertical stratification in\u00a0groundwater flow.<\/span><\/p>\n The\u00a0findings underscore the\u00a0importance of\u00a0detailed hydrogeological knowledge, continuous monitoring, periodic review of\u00a0abstraction limits, and method refinement. The\u00a0study concludes by stressing the\u00a0need to protect infiltration areas and adopt long-term sustainable groundwater management strategies in\u00a0the\u00a0face of\u00a0climate change and increasing anthropogenic pressures.<\/span><\/p>\n This article summarises the\u00a0development of\u00a0groundwater balance assessment in\u00a0Czechoslovakia and the\u00a0Czech Republic from the\u00a01960s to the\u00a0present. It focuses on changes in\u00a0approaches to evaluating the\u00a0usability and balance of\u00a0groundwater resources, as well as the\u00a0methodological foundations and institutional frameworks that have gradually evolved in\u00a0response to new knowledge, legislative changes, and the\u00a0requirements of\u00a0practice and European Union directives.<\/span><\/p>\n The\u00a0text documents the\u00a0beginnings of\u00a0groundwater balance assessment, which were closely linked to the\u00a0activities of\u00a0the\u00a0specialised subcommittee for groundwater within\u00a0the\u00a0Commission for the\u00a0Classification of\u00a0Deposits, where emphasis was placed on determining the\u00a0so-called utilisable reserves. However, these values often did not reflect the\u00a0seasonal or long-term variability of\u00a0the\u00a0natural regime. A\u00a0significant advance came with the\u00a0introduction of\u00a0abstraction records in\u00a0the\u00a01970s, which enabled the\u00a0compilation of\u00a0regular annual balances that became part of\u00a0the\u00a0state water management balance.<\/span><\/p>\n Since the\u00a01990s, the\u00a0methodology has approached the\u00a0requirement for data comparability (i.e., the\u00a0comparison of\u00a0actual abstractions with resources for the\u00a0same period), with detailed monthly balances becoming necessary in\u00a0stressed areas. The\u00a080% quantile of\u00a0base flow has become a\u00a0key parameter. The\u00a0text describes the\u00a0current form of\u00a0water management balance according to the\u00a0valid Water Act and associated implementing regulations. It distinguishes between hydrological and water management balance, outlines the\u00a0roles of\u00a0individual institutions (CHMI, river basin\u00a0authorities, and TGM WRI), and explains the\u00a0principles of\u00a0recording abstractions, reporting procedures, and data categorisation.<\/span><\/p>\n A\u00a0separate section is devoted to hydrogeological zoning as a\u00a0fundamental tool for spatial division of\u00a0groundwater. The\u00a0text traces the\u00a0development of\u00a0zoning from the\u00a01950s to its most recent version in\u00a02005\u00a0[1], which brought it into alignment with groundwater bodies defined for the\u00a0purposes of\u00a0river basin\u00a0management plans and EU legislation. Emphasis is placed on the\u00a0criteria for zoning, the\u00a0link to balance units, and the\u00a0connection with delineated water bodies.<\/span><\/p>\n \u00a0<\/span>Research on balance assessment methods in\u00a0recent decades has highlighted the\u00a0need for a\u00a0specific approach to certain\u00a0hydrogeological environments and structures, for which established procedures based on standard hydrological methods and base flow calculations cannot be mechanically applied. These include Quaternary deposits closely linked to surface water, karst structures, deep basin\u00a0collectors, regional drainage areas, and similar features.<\/span><\/p>\n The\u00a0practical approach to balance assessment is demonstrated using four Upper Cretaceous HGR, which are often described as balance-stressed.<\/span><\/p>\n The\u00a0two fundamental terms used in\u00a0groundwater balance assessment are\u00a0hydrological balance and water management balance.<\/span><\/p>\n Hydrological balance evaluates changes in\u00a0surface and groundwater stocks caused by temporal and spatial variability of\u00a0natural factors, particularly climatic influences, and provides a\u00a0basis for assessing changes in\u00a0water stocks resulting from water use or other anthropogenic interventions. Thus, hydrological balance concerns the\u00a0determination of\u00a0natural groundwater resources within\u00a0the\u00a0context of\u00a0the\u00a0entire hydrological cycle, including spatiotemporal variability of\u00a0quantitative characteristics. At present, the\u00a0magnitude of\u00a0natural resources is significantly influenced not only by seasonal climate variability but also by long-term trends associated with ongoing climate change. Today, the\u00a0calculation of\u00a0hydrological balance is inconceivable without the\u00a0use of\u00a0various hydrological and hydraulic mathematical models.<\/span><\/p>\n Water management balance is the\u00a0comparison of\u00a0water abstraction demands with the\u00a0magnitude of\u00a0natural resources at a\u00a0given location and time. In\u00a0this way, water management balance provides an overview of\u00a0the\u00a0state of\u00a0water resources, degree of\u00a0utilisation, and potential for future increases. Comparison of\u00a0natural resources and groundwater abstractions forms the\u00a0basis for assessing the\u00a0balance stress of\u00a0a\u00a0given area. Modern water management balance assessment relies on a\u00a0set of\u00a0advanced statistical analyses and procedures. The\u00a0results of\u00a0water management balance constitute a\u00a0fundamental basis for water management planning and governance.<\/span><\/p>\n Hydrological and water management balances together form the\u00a0so-called water balance, as defined by the\u00a0Water Act\u00a0[2].<\/span><\/p>\n The\u00a0following provides an overview of\u00a0the\u00a0gradual development of\u00a0groundwater balance assessment in\u00a0Czech Republic:<\/span><\/p>\n Monitoring and assessment of\u00a0the\u00a0status of\u00a0surface and groundwater, in\u00a0accordance with Section 21 of\u00a0the\u00a0Water Act\u00a0[2], serve to provide the\u00a0basis for the\u00a0exercise of\u00a0public administration under said Act, for water planning (Chapter\u00a0IV, Water Act), and for the\u00a0provision of\u00a0information to the\u00a0public. It is carried out according to surface water catchments and HGRs, or groundwater bodies, and includes, among other things, maintenance of\u00a0water balance (Section 21(2)(b), Water Act) and establishment, management, and updating of\u00a0records pursuant to Section 21(2)(c), Water Act. The\u00a0data contained in\u00a0these records form part of\u00a0the\u00a0Public Administration Information System \u2013 VODA\u00a0[3].<\/span><\/p>\n Water balance consists of\u00a0hydrological balance and water management balance. Hydrological balance compares water gains and losses and changes in\u00a0water storage within\u00a0a\u00a0catchment, territory, or water body over a\u00a0given time interval, and it is compiled by CHMI. Water management balance compares requirements for surface water abstractions, groundwater abstractions, and wastewater discharges with the\u00a0available capacity of\u00a0water resources in\u00a0terms of\u00a0quantity, quality, and ecological status (Section 22(1), Water Act). It is compiled, within\u00a0their territorial jurisdiction, by the\u00a0state-owned river basin\u00a0authorities pursuant to Section 54 of\u00a0the\u00a0Water Act\u00a0[2] and further in\u00a0accordance with Section 5(3) of\u00a0Decree No. 431\/2001 Coll.\u00a0[4]. Comprehensive annual and nationwide processing of\u00a0water management balance data is carried out by TGM\u00a0WRI\u00a0[5].<\/span><\/p>\n For the purposes of water management balance, CHMI has always provided source-side data of the balances by determining baseflow on the basis of information from the national monitoring network, groundwater level observations, and strength of source. This indicator of natural groundwater resources is processed\u00a0<\/span>annually from current data of\u00a0monitoring stations. To track development of\u00a0these resources over longer periods, the\u00a0value of\u00a0natural resources derived from long-term monitoring is used (a\u00a030-year period, currently 1991\u20132020). Therefore, balance assessment includes a\u00a0comparison of\u00a0abstractions both with the\u00a0value of\u00a0actual natural resources of\u00a0the\u00a0previous year and with the\u00a0value of\u00a0long-term natural resources. The\u00a0requirements of\u00a0the\u00a0EU Water Framework Directive have been reflected in\u00a0methodological procedures used by TGM WRI in\u00a0agreement with MoE (Water Protection Department). Instead of\u00a0calculating baseflow, comprehensive assessment of\u00a0natural groundwater resources is now anticipated, since baseflow alone may not be determinative in\u00a0some environments (groundwater bodies in\u00a0close hydraulic connection with surface waters, karst areas, drainage areas composed of\u00a0several hydrogeological aquifers, deep basin\u00a0aquifers with long residence times, etc.). In\u00a0such cases, it is particularly necessary to apply modern research methods, including isotope analyses and hydraulic modelling procedures.<\/span><\/p>\n It is not yet possible to determine the\u00a0size of\u00a0natural resources for all HGRs \u2013 either they are so affected by anthropogenic activity that determination is unrealistic, or data are not available in\u00a0the\u00a0required structure and detail, or methodological uncertainties persist (e.g., for Quaternary regions closely linked to a\u00a0watercourse). The\u00a0key characteristic expressing resource capacity of\u00a0a\u00a0hydrogeological structure is the\u00a0value of\u00a0the\u00a0natural resource, usually expressed in\u00a0l\/s\u00a0and related to the\u00a0area of\u00a0the\u00a0assessed territory (generally an HGR) and the\u00a0assessment period. Natural groundwater resources are determined for each month and year, as well as the\u00a0average value over a\u00a0given monitoring period. Values of\u00a0natural resources are established by CHMI as part of\u00a0hydrological balance.<\/span><\/p>\n For selected HGRs, the\u00a0Czech Geological Survey carried out a\u00a0detailed reassessment of\u00a0natural resources in\u00a0the\u00a0project Rebalancing of\u00a0Groundwater Reserves<\/span>\u00a0[6], conducted from 2011 to 2016. Advanced numerical hydrological and hydraulic models were used for rebalancing of\u00a0natural resources (rebalancing because earlier balances existed with varying quality) with input data from archival research, drilling works, hydrological and borehole logging measurements, and other direct observations, and with retrospective verification against actual data. One of\u00a0the\u00a0outputs is value of\u00a0utilisable groundwater, based on 90% security of\u00a0natural resources, considering the\u00a0requirement to maintain\u00a0minimum residual flows in\u00a0the\u00a0river network while ensuring sufficient water availability for groundwater-dependent protected ecosystems.<\/span><\/p>\n Under Section 29 of\u00a0the\u00a0Water Act\u00a0[2], groundwater resources are primarily reserved for the\u00a0supply of\u00a0drinking water to the\u00a0population and for purposes for which the\u00a0use of\u00a0drinking water is prescribed by Act no. 258\/2000 Coll.\u00a0[7]. Groundwater may be used for other purposes provided that such use does not compromise the\u00a0needs mentioned above.<\/span><\/p>\n For the\u00a0purposes of\u00a0the\u00a0water management balance under Section\u00a022 of\u00a0the\u00a0Water Act\u00a0[2], groundwater users holding a\u00a0permit to abstract groundwater in\u00a0amounts exceeding 1,000\u00a0m\u00b3 per calendar year or 100\u00a0m\u00b3 per calendar month (limits effective from 2022) are required to report annually to the\u00a0relevant river basin\u00a0authorities the\u00a0quantities of\u00a0groundwater abstracted (as set out in\u00a0Section\u00a010 of\u00a0the\u00a0Act). The\u00a0scope of\u00a0these reported data and the\u00a0procedure for reporting to the\u00a0relevant river basin\u00a0authority are defined in\u00a0Sections\u00a010 and 11 of\u00a0Decree No. 431\/2001 Coll.\u00a0[4]. In\u00a0the\u00a0assessment of\u00a0groundwater quantity and quality, in\u00a0accordance with Decree No.\u00a0393\/2010 Coll.\u00a0[8], abstractions exceeding 6,000\u00a0m\u00b3 per calendar year or 500\u00a0m\u00b3 per calendar month are included in\u00a0the\u00a0balance.<\/span><\/p>\n The\u00a0basic unit of\u00a0groundwater balance is HGR. It is an area with similar hydrogeological conditions, type of\u00a0aquifer, and groundwater flow, composed of\u00a0one or more groundwater bodies.<\/span><\/p>\n Zones are delineated based on natural characteristics in\u00a0the\u00a0upper, main, and deep layers.<\/span><\/p>\n Groundwater management balance is based on a standard procedure \u2013 determining the ratio of groundwater abstractions to natural resources in a defined territory and period. The size of natural resources represents the natural dynamic component of groundwater, expressed in volumetric units over time (l\/s), and is generally determined in practice by the variable magnitude of baseflow. Baseflow magnitude of is determined as part of the outputs of the hydrological balance of water quantity at CHMI, where specific values are calculated for individual HGRs based on measurements. HGR is the basic balance unit for\u00a0<\/span>assessing groundwater quantity and includes one or several usually closed hydrogeological structures. In\u00a0other cases as well (e.g.,\u00a0regional hydrogeological surveys from the\u00a01960s to 1980s or the\u00a0Rebalancing of\u00a0Groundwater Reserves<\/span> project), natural resource data were always collected within\u00a0HGRs; therefore, more detailed data for smaller areas are generally not available.<\/span><\/p>\n Baseflow calculation (CHMI) is derived from total flow on a\u00a0daily basis using the\u00a0separation method according to Eckhardt. The\u00a0recession coefficient is determined from an analysis of\u00a0flow recession curves. The\u00a0ratio of\u00a0total to baseflow, BFImax, is calibrated to match the\u00a0course of\u00a0total and baseflow during the\u00a0falling limbs of\u00a0the\u00a0hydrograph. Static groundwater reserves are determined from the\u00a0Boussinesq equation, which relates storage to baseflow.<\/span><\/p>\n Groundwater management balance is processed annually, currently for approximately 102 HGRs (for 2023) out of\u00a0a\u00a0total of\u00a0152, covering just under 81\u00a0% of\u00a0the\u00a0area of\u00a0Czech Republic (Fig.\u00a03<\/span><\/em>). The\u00a0reason for not calculating baseflow in\u00a0Quaternary sediments is the\u00a0lack of\u00a0input data and often the\u00a0complex assessment of\u00a0resources in\u00a0these types of\u00a0HGR, where both the\u00a0influence of\u00a0surface water and drainage of\u00a0deeper hydrogeological structures are evident. Due to ongoing methodological uncertainties and the\u00a0incomparability of\u00a0the\u00a0obtained values, balance assessment for these HGRs has not yet been carried out for the\u00a0purposes of\u00a0water management balance.<\/span><\/p>\n In\u00a0the\u00a0balance of\u00a0groundwater quantity, total abstractions are compared with values of\u00a0natural groundwater resources within\u00a0the\u00a0spatial unit (HGR, see Fig.\u00a03<\/span>). As a\u00a0precautionary measure, TGM WRI, in\u00a0agreement with the\u00a0MoE (Water Protection Department) and the\u00a0MoA (Water Management Department), adopted a\u00a0methodological approach in\u00a0which zones are assessed by the\u00a0ratio of\u00a0maximum monthly abstraction in\u00a0a\u00a0given year to minimum monthly baseflow in\u00a0the\u00a0same year (MAX\/MIN)\u00a0[12\u201314]. This thus identifies the\u00a0potentially most unfavourable state within\u00a0the\u00a0assessed year. If the\u00a0MAX\/MIN ratio exceeds 0.5, the\u00a0zones are considered balance-stressed, and further assessment in\u00a0a\u00a0monthly step is required, comparing monthly baseflow values with actual monthly abstractions. If balance stress is confirmed by the\u00a0analysis of\u00a0monthly data, a\u00a0detailed hydrogeological assessment of\u00a0the\u00a0zone should follow, including a\u00a0groundwater flow hydraulic model, to determine the\u00a0actual situation, identify the\u00a0problem, and explore possible remediation measures. An interesting question could be how balance stress of\u00a0zones would appear if permitted abstractions were used instead of\u00a0actual abstractions; however, this is beyond the\u00a0scope of\u00a0this article.<\/span><\/p>\n Fig.\u00a03<\/span><\/span><\/em> shows the\u00a0area from which four HGRs of\u00a0the\u00a0Bohemian Cretaceous Basin\u00a0were selected as examples of\u00a0the\u00a0applied procedures; these HGRs are regularly reported as balance-stressed. Currently, the\u00a0HGRs with regularly reported balance stress 4522, 4410, and 4430 are part of\u00a0applied research funded by TA CR (projects no.\u00a0SS06010268 Understanding, Quantification, and Protection of\u00a0Strategic Deep-Circulation Groundwater Resources of\u00a0the\u00a0Bohemian Cretaceous Basin\u00a0in\u00a0HGRs 4410 and 4522<\/span> and no.\u00a0SQ01010176 Impacts of\u00a0Climate Change on Minimum Residual Flows in\u00a0the\u00a0Jizera River Network and on Groundwater Abstractions Near the\u00a0River<\/span>). Due to spatial continuity, the\u00a0neighbouring HGR\u00a04523, which is also reported as stressed, was included in\u00a0the\u00a0assessment for the\u00a0purposes of\u00a0this article.<\/span><\/p>\n Key results are expected primarily from project no.\u00a0SS06010268, which aims to improve understanding of\u00a0the\u00a0hydrogeological basin\u00a0environment of\u00a0the\u00a0Upper Cretaceous sediments and, among other objectives, to determine whether the\u00a0regularly observed balance stress might also be related to incorrect delineation of\u00a0current zone boundaries, which may not fully characterise closed hydrogeological structures. There are already strong indications (tritium analyses, residence time calculations, tracer results using CFC\/SF6, and a\u00a0conceptual groundwater flow model\u00a0[15, 16]) that call for a\u00a0new perspective on groundwater flow directions at the\u00a0interface of\u00a0HGR\u00a04522, 4410, 4521, and 4640. If these new perspectives are confirmed, the\u00a0research results could also be reflected in\u00a0the\u00a0assessment of\u00a0balance stress in\u00a0these areas.<\/span><\/p>\n To illustrate the\u00a0results achieved in\u00a0water management balance assessment, four HGRs were used:<\/span><\/p>\n The\u00a0selected HGRs have long been classified as balance-stressed (Fig.\u00a03<\/span><\/em>), noting that this assessment considers the\u00a0most unfavourable condition within\u00a0a\u00a0given year (i.e., the\u00a0ratio of\u00a0maximum monthly abstraction to minimum monthly baseflow exceeds 0.5). This serves as an initial signal that, when a\u00a0region is flagged as stressed, further evaluation in\u00a0a\u00a0monthly step is required to reveal the\u00a0distribution of\u00a0these indicators over the\u00a0entire period. HGR\u00a04410\u00a0has been classified as stressed regularly since 2016, HGR\u00a04430 since 2012, and HGRs 4522 and 4523 since 2007 and 2008, respectively.<\/span><\/p>\n The\u00a0named HGRs were therefore assessed with respect to natural groundwater resources and abstractions for the\u00a0period 2007\u20132023. The\u00a0assessment first compared maximum monthly abstraction with minimum monthly baseflow alongside long-term baseflow values (1971\u20132000, 1981\u20132010, and 1991\u20132020) and then compared monthly baseflow with actual monthly abstractions over 2007\u20132023.<\/span><\/p>\n The\u00a0area contains two separate hydrogeological Cretaceous aquifers. Basal aquifer A\u00a0(which is part of\u00a0two deep-layer HGRs \u2013 HGR\u00a04710 Basal Cretaceous aquifer on the\u00a0Jizera and HGR\u00a04720 Basal Cretaceous aquifer from Hamr to the\u00a0Elbe) is hosted in\u00a0Cenomanian-age siltstones and sandstones, whereas aquifer\u00a0C (forming the\u00a0main\u00a0part of\u00a0HGR\u00a04410 in\u00a0the\u00a0main\u00a0layer) is hosted in\u00a0Turonian-age sandstones and siltstones. The\u00a0claystone sequence at the\u00a0base of\u00a0the\u00a0Lower Turonian acts as a\u00a0hydrogeological confining layer between the\u00a0two aquifers and, by extension, between the\u00a0HGRs. The\u00a0main\u00a0source of\u00a0groundwater for water supply abstractions in\u00a0HGR\u00a04410 is the\u00a0sandstones of\u00a0the\u00a0Jizera Formation, serving as Hydrogeological aquifer C. Part of\u00a0the\u00a0area is overlain\u00a0by an artesian cover of\u00a0Coniacian claystones\u00a0[10]. Groundwater recharge occurs partly within\u00a0the\u00a0area of\u00a0the\u00a0HGR and partly via lateral inflow from adjacent HGRs, or through inflow from the\u00a0Jizera River. It is clear that the\u00a0largest abstractions from HGR\u00a04410, in\u00a0the\u00a0Koch\u00e1nky catchment, are in\u00a0close hydraulic connection with the\u00a0Jizera River (abstractions from the\u00a0Quaternary sediments of\u00a0the\u00a0Jizera, which form part of\u00a0HGR\u00a04410). Abstractions in\u00a0the\u00a0B\u011bl\u00e1 and Strenick\u00fd Stream catchments may be associated with lateral groundwater inflows from outside HGR\u00a04410.<\/span><\/p>\n Fig.\u00a04<\/span><\/span><\/em> shows that annual abstraction values remain\u00a0consistently below natural resource values, or baseflow, which also holds for comparison of\u00a0maximum monthly abstraction and minimum monthly baseflow. However, the\u00a0MAX\/MIN ratio criterion of\u00a00.5 is regularly exceeded, and the\u00a0HGR is therefore repeatedly classified as balance-stressed. Since 2014, a\u00a0gradual convergence of\u00a0the\u00a0two values can be observed, primarily due to declining natural resources while abstraction volumes have remained constant (the\u00a0MAX\/MIN ratio is gradually increasing). A\u00a0clear decline (about 20\u202f%) is also evident in\u00a0the\u00a0consecutive 30-year averages of\u00a0natural resources (1971\u20132000, 1981\u20132010, 1991\u20132020), undoubtedly reflecting the\u00a0impacts of\u00a0climate change. Comparison of\u00a0baseflow and monthly abstraction values (Fig.\u00a05<\/span><\/em>) shows that abstractions remain\u00a0consistently below baseflow in\u00a0the\u00a0monthly view, yet often represent more than 50\u00a0% of\u00a0natural resources (baseflow); classification of\u00a0the\u00a0HGR as balance-stressed is therefore justified according to the\u00a0applied methodology.<\/span><\/p>\n Three separate hydrogeological Cretaceous aquifers have developed in\u00a0the\u00a0area\u00a0[10]:<\/span><\/p>\n HGR 4430 is largely overlain by an artesian cover of Coniacian aleurites. Recharge of groundwater via direct infiltration within the area of the HGR is very limited; the majority is indirect, mediated by inflow from HGRs 4420 and 4410, or by inflow from the Jizera River, especially at abstraction points. It is indisputable that the largest abstractions from HGR 4430, in Ben\u00e1tky nad\u00a0<\/span>Jizerou (from the\u00a0Quaternary deposits of\u00a0the\u00a0Jizera), are in\u00a0significant hydraulic connection with the\u00a0Jizera River. Hydraulic connection with surface waters can also be expected for other, smaller abstractions across the\u00a0HGR.<\/span><\/p>\n Fig.\u00a06<\/span><\/span><\/em> shows that annual values of\u00a0average abstractions remain\u00a0consistently below the\u00a0values of\u00a0average natural resources, i.e., baseflow. However, the\u00a0MAX\/MIN criterion of\u00a00.5 is regularly exceeded, so the\u00a0HGR is consistently classified as balance-stressed. Since 2014, a\u00a0pronounced convergence of\u00a0the\u00a0two values can also be observed, primarily due to declining natural resources while abstraction volumes remain\u00a0constant (the\u00a0MAX\/MIN ratio gradually increases). Comparison of\u00a0monthly values (Fig.\u00a07<\/span>) of\u00a0abstractions and baseflow shows that abstractions occasionally exceed natural resource values and, especially after 2015, this long-term unsustainable situation has become the\u00a0norm. The\u00a0impact of\u00a0the\u00a0prolonged drought period 2015\u20132019 is also evident, as the\u00a0most recent 30-year average of\u00a0natural resources (1991\u20132020) is the\u00a0lowest (up to 27\u00a0% below the\u00a01971\u20132020 Both HGR encompass the area of right-bank tributaries of the Elbe River from M\u011bln\u00edk to Litom\u011b\u0159ice, where the catchments of the P\u0161ovka, Lib\u011bchovka, Obrtka, and \u00da\u0161t\u011bck\u00fd potok Streams experience significant drainage of the Cretaceous Basin sediments (key infiltration areas partly lie outside these HGR) and where very substantial water-supply abstractions take place. The area contains two\u00a0<\/span>main\u00a0hydrogeological aquifers: basal aquifer A, associated with Cenomanian psammites and psephites (forming part of\u00a0the\u00a0deep-layer hydrogeological aquifer 4720 Basal aquifer from Hamr to the\u00a0Elbe River), and aquifer C, associated with Turonian sediments of\u00a0the\u00a0Jizera Formation, which forms the\u00a0HGR\u00a04522 and 4523 discussed here. The\u00a0Quaternary aquifer is hydraulically connected to aquifer C and cannot be separately delineated or assessed; it is therefore considered part of\u00a0both HGR\u00a04522 and 4523\u00a0[10]. Significant groundwater abstractions occur here from the\u00a0\u0158ep\u00ednsk\u00fd d\u016fl, Zah\u00e1j\u00ed, M\u011blnick\u00e1 Vrutice catchments, and other sources.<\/span><\/p>\n It is evident from Fig.\u202f8<\/span><\/em> that the\u00a0annual values of\u00a0average abstractions in\u00a0HGR\u202f4522 are mostly higher than the\u00a0values of\u00a0natural resources, or baseflow. When comparing the\u00a0maximum monthly abstraction with minimum monthly baseflow, this difference becomes even more pronounced and persists throughout almost the\u00a0entire assessment period 2007\u20132023. Since 2018, the\u00a0gap between natural resources and abstractions has further increased, mainly due to a\u00a0slight decline in\u00a0natural resources while abstraction volumes have remained relatively constant. The\u00a0MAX\/MIN ratio criterion of\u00a00.5 is thus regularly exceeded (reaching values above 1), so the\u00a0district is justifiably classified as balance-stressed on a\u00a0regular basis. The\u00a0impact of\u00a0the\u00a02015\u20132019 drought period is also clearly visible, resulting in\u00a0the\u00a0lowest 30-year average of\u00a0natural resources for 1991\u20132020 compared with the\u00a0two preceding periods (1971\u20132000, 1981\u20132010), with a\u00a0reduction of\u00a0up to 24\u202f% relative to 1971\u20132020, undoubtedly reflecting the\u00a0long-term effects of\u00a0climate change. Comparison of\u00a0monthly values of\u00a0baseflow and abstractions (Fig.\u202f9<\/span><\/em>) shows that until around 2015 the situation was relatively more favourable (abstractions were mostly below baseflow values, although even then they exceeded 50\u202f% of baseflow). From\u00a0<\/span>approximately 2018 onwards, however, monthly abstractions consistently exceed baseflow values, representing a\u00a0long-term unacceptable condition that should manifest in\u00a0declining groundwater levels and static reserves (so called overexploitation of\u00a0the\u00a0hydrogeological structure).<\/span><\/p>\n Fig.\u00a010<\/span><\/span><\/em> shows the\u00a0state of\u00a0water balance stress in\u00a0HGR\u00a04523. The\u00a0situation here is a\u00a0bit more favourable. Abstractions are mostly lower than the\u00a0values of\u00a0the\u00a0annual average of\u00a0natural resources, but from around 2015 the\u00a0abstraction and natural resource values have approached each other significantly, mainly due to a\u00a0decline in\u00a0natural resources. Thanks to the\u00a0current decrease in\u00a0abstractions, the\u00a0values have not yet exceeded natural resources. However, the\u00a0MAX\/MIN ratio criterion of\u00a00.5 is regularly and consistently exceeded, and the\u00a0district is therefore correctly classified as balance-stressed. A\u00a0clear and very pronounced decline is also evident in\u00a0successive 30-year averages of\u00a0natural resources (1971\u20132000, 1981\u20132010, 1991\u20132020), reaching up to 37\u202f% over the\u00a0period 1971\u20132020, undoubtedly reflecting the\u00a0impacts of\u00a0climate change. Comparison of\u00a0monthly baseflow and abstraction values (Fig.\u202f11<\/span><\/em>) indicates a\u00a0more favourable situation; for most of\u00a0the\u00a0assessment period, monthly abstractions remain\u00a0below monthly natural resource values (if the\u00a0fluctuating baseflow values of\u00a02009\u20132011 are disregarded, the\u00a0opposite occurred only in\u00a02018, and in\u00a0recent years the\u00a0situation has improved further due to a\u00a0decline in\u00a0recorded abstractions). The\u00a0MAX\/MIN ratio criterion of\u00a00.5 is exceeded only rarely from the\u00a0perspective of\u00a0monthly values. From a\u00a0methodological point of\u00a0view, this demonstrates the\u00a0great utility of\u00a0assessing balance stress in\u00a0a\u00a0monthly step.<\/span><\/p>\n Total abstractions from HGR\u00a04410\u00a0have not caused regional declines in\u00a0groundwater levels or reductions in\u00a0static reserves. Its classification as a\u00a0balance-stressed HGR (Fig.\u202f3<\/span><\/em>) is, however, justified by frequent exceedances of\u00a0MAX\/MIN criterion (Fig.\u202f4<\/span>), including after balance analysis in\u00a0a\u00a0monthly step (Fig.\u202f5<\/span><\/em>). Balance stress may occur locally, particularly in\u00a0areas with large abstractions. It should also be noted that the\u00a0difference between natural resources and abstractions is gradually decreasing, both on an annual and a\u00a0monthly basis (see also progressively declining 30-year averages of\u00a0natural resources), which, in\u00a0connection with the\u00a0impacts of\u00a0climate change, raises some concern about a\u00a0further increase in\u00a0balance stress in\u00a0the\u00a0future. However, where certain\u00a0abstractions from the\u00a0B\u011bl\u00e1 and Strenick\u00fd Streams are largely fed by groundwater originating from more distant recharge areas with longer residence times\u00a0[16], the\u00a0impacts of\u00a0climate change on these abstractions can be expected to be considerably smaller.<\/span><\/p>\n From the\u00a0perspective of\u00a0protecting the\u00a0groundwater resources of\u00a0HGR\u00a04410, we recommend that any future large abstractions be approved only after careful consideration of\u00a0the\u00a0available groundwater resources and their origin. Climate change will undoubtedly limit shallow-circulation resources. However, deeper groundwater flow with longer residence times (particularly from the\u00a0west to northwest from HGR\u00a04640), which is considerably more resilient to the\u00a0impacts of\u00a0climate change, offers significant potential for utilisation of\u00a0these less vulnerable groundwater resources, whose quantification is also being addressed by the\u00a0currently ongoing TA CR project no.\u00a0SS06010268\u00a0[15]. In\u00a0protecting the\u00a0recharge of\u00a0this deeper groundwater flow, the\u00a0protection of\u00a0infiltration areas is essential, particularly those at higher altitudes and with higher precipitation totals. Given the\u00a0presence of\u00a0the\u00a0Jizera River and some other watercourses, there is also a\u00a0certain\u00a0potential in\u00a0this HGR to increase groundwater resources through the\u00a0application of\u00a0managed aquifer recharge methods\u00a0[19].<\/span><\/p>\n Total abstractions from HGR\u00a04430\u00a0have not yet caused regional declines in\u00a0groundwater levels or reductions in\u00a0static reserves; however, its classification among balance-stressed HGRs (Fig.\u202f3<\/span><\/em>) is fully justified due to frequent exceedances of\u00a0the\u00a0MAX\/MIN criterion (Fig.<\/span>\u202f6<\/em>), even after balance analysis in\u00a0a\u00a0monthly step (Fig.<\/span>\u202f7<\/em>). Especially since 2014, abstraction values and natural resources have become very close, primarily as a\u00a0result of\u00a0declining natural resources due to climate change. Even after balance analysis in\u00a0a\u00a0monthly step (Fig.<\/span>\u202f7<\/em>), it is evident that the\u00a0two curves are close to each other, and there are even months in\u00a0which total abstractions exceed baseflow values (the\u00a0MAX\/MIN ratio thus exceeds 1). It is also important to note the\u00a0sharply declining 30-year averages of\u00a0natural resources (by 27\u202f% over the\u00a0period 1971\u20132020), which \u2013 considering the\u00a0impacts of\u00a0climate change \u2013 raises further concerns for the\u00a0future. These could result in\u00a0either managed or unmanaged reductions in\u00a0abstractions, or in\u00a0abstractions being carried out at the\u00a0expense of\u00a0surface flows (the\u00a0Jizera River and its tributaries).<\/span><\/p>\n From the perspective of protecting groundwater resources in HGR\u202f4430, it should be noted that further available resources are relatively limited. In the future, any additional large abstractions should be permitted only after careful consideration of the local situation and balance stress. Relatively higher yields may be provided by sources relying on induced inflows from nearby surface streams (the Jizera River and its tributaries); however, during prolonged droughts, this could have adverse effects on streamflow characteristics and\u00a0<\/span>the\u00a0ecological functions of\u00a0these watercourses. For the\u00a0protection of\u00a0groundwater recharge in\u00a0HGR\u202f4430, it is essential to safeguard infiltration areas in\u00a0HGR\u202f4420 Jizera Coniacian and to consider abstraction volumes in\u00a0the\u00a0neighbouring HGR\u202f4410 and 4420; a\u00a0substantial increase in\u00a0these abstractions would reduce the\u00a0inflows from these zones into HGR\u202f4430. It is therefore recommended, from a\u00a0water balance perspective, that these three HGR be assessed together. Given the\u00a0presence of\u00a0the\u00a0Jizera River and other watercourses, there is also some potential in\u00a0this HGR to increase groundwater resources through the\u00a0application of\u00a0managed aquifer recharge methods\u00a0[19].<\/span><\/p>\n It appears that the\u00a0Cretaceous formations of\u00a0the\u00a0right-bank tributaries of\u00a0the\u00a0Elbe are an area where significant groundwater abstractions, combined with pronounced effects of\u00a0climate change, result in\u00a0actual water balance stress or a\u00a0serious threat thereof. Observed phenomena include losses of\u00a0water from surface streams (meaning that abstractions are effectively carried out at the\u00a0expense of\u00a0groundwater discharge to surface flow), and in\u00a0some cases abstractions even actively induce a\u00a0loss of\u00a0surface water from the\u00a0stream due to bank infiltration, all of\u00a0which affect flow characteristics and minimum residual flows. A\u00a0negative impact has been recorded on the\u00a0lower course of\u00a0the\u00a0P\u0161ovka (due to complex groundwater flow conditions), where part of\u00a0the\u00a0stream dries out during summer months over extended periods. Impacts have also been observed on some other streams (the\u00a0Obrtka).<\/span><\/p>\n The\u00a0situation has been closely monitored over the\u00a0long term, and various measures have been implemented. Based on the\u00a0Lower Elbe River Basin\u00a0Management Plan (measures sheets), numerous studies have been carried out, and a\u00a0series of\u00a0joint meetings and hydrogeological surveys have taken place. From all these findings, the\u00a0need for remedial and protective measures has emerged, including a\u00a0reduction in\u00a0groundwater abstractions (see reduction in\u00a0abstractions after 2019 in\u00a0Fig.\u00a011<\/span>). At present, the\u00a0water supply operator holds a\u00a0permit for groundwater abstraction from the\u00a0\u0158ep\u00ednsk\u00fd d\u016fl, Zah\u00e1j\u00ed, and M\u011blnick\u00e1 Vrutice sites, amounting to 370\u202fl\/s, in\u00a0which the\u00a0maximum allowable abstraction at this site has already been significantly reduced. Within\u00a0the\u00a0M\u011blnick\u00e1 Vrutice catchment, regime monitoring is carried out with detailed evaluation. Monitoring results indicate that use of\u00a0the\u00a0P\u0161ovka catchment is close to 100\u00a0% of\u00a0current natural groundwater resources.<\/span><\/p>\n HGR\u00a04522 is classified as highly stressed in\u00a0terms of\u00a0water balance, and this must be considered when permitting further groundwater abstractions within\u00a0this HGR, especially in\u00a0view of\u00a0the\u00a0anticipated deepening impacts of\u00a0climate change on water conditions. For HGR\u00a04523, the\u00a0situation is only slightly more favourable. However, it shows the\u00a0greatest decline in\u00a0natural resources over the\u00a0period 1971\u20132020 of\u00a0all four assessed HGRs \u2013 up to 37\u202f%. This represents the\u00a0fastest reduction in\u00a0available natural resources, offering a\u00a0rather pessimistic outlook for future water balance stress.<\/span><\/p>\n If research within\u00a0TA CR project no.\u00a0SS06010268 demonstrates that part of\u00a0the\u00a0groundwater resources originates from outside HGR\u00a04522\u00a0[15,\u202f16], this could reduce water balance stress in\u00a0HGR\u00a04522. Simultaneously, the\u00a0conceptual model indicates the\u00a0existence of\u00a0separate groundwater flow in\u00a0deeper Turonian sub-aquifers, which was identified as part of\u00a0the\u00a0Rebalancing Groundwater Resources<\/span> project. In\u00a0the\u00a0future, it would therefore be logical to process water balance at the\u00a0level of\u00a0these sub-aquifers, as there appears to be a\u00a0significant difference in\u00a0balance stress among them. However, a\u00a0legitimate question remains as to whether there will be sufficient relevant data to carry out such a\u00a0detailed sub-aquifer balance.<\/span><\/p>\n From the\u00a0perspective of\u00a0protecting groundwater resources in\u00a0HGR\u00a04522 and 4523, it should be noted that additional available resources are fairly limited. In\u00a0the\u00a0future, further large abstractions should not be permitted, or only allowed after careful consideration of\u00a0the\u00a0situation, the\u00a0state of\u00a0local water balance stress, and verification of\u00a0the\u00a0age and origin\u00a0of\u00a0the\u00a0water inflow. Climate change will undoubtedly limit shallow-circulation resources. Deeper groundwater flow with a\u00a0longer residence time, which is significantly more resilient to the\u00a0impacts of\u00a0climate change, does, however, provide certain\u00a0opportunities for the\u00a0utilisation of\u00a0these less vulnerable groundwater resources\u00a0[15,\u202f16]. In\u00a0protecting the\u00a0formation of\u00a0groundwater in\u00a0this deeper flow, it is crucial to safeguard the\u00a0recharge areas (both the\u00a0areas of\u00a0the\u00a0two HGRs of\u00a0interest and of\u00a0HGR\u00a04640 with higher elevations and greater precipitation totals). Theoretically, there is also some potential in\u00a0both HGRs to increase groundwater resources through the\u00a0application of\u00a0managed aquifer recharge methods\u00a0[19]; however, these considerations are constrained by the\u00a0limited availability of\u00a0surface water sources and lower precipitation totals. In\u00a0practice, the\u00a0only significant water source for infiltration is the\u00a0Elbe River, so the\u00a0southern parts of\u00a0both HGRs could be considered for discussions on this topic, which would, however, need to include considerations of\u00a0water quality of\u00a0the\u00a0Elbe.<\/span><\/p>\n This text focuses on the long-term evaluation of water management balance in selected HGRs of the Czech Cretaceous Basin for the period 2007\u20132023, specifically HGR\u00a04410 (Cretaceous of\u00a0the\u00a0Jizera River, right-bank part), HGR\u00a04430 (Cretaceous of\u00a0the\u00a0Jizera River, left-bank part), HGR\u00a04522 (Cretaceous of\u00a0the\u00a0Lib\u011bchovka and P\u0161ovka Streams), and HGR\u00a04523 (Cretaceous of\u00a0the\u00a0Obrtka and \u00da\u0161t\u011bck\u00fd potok Streams). The\u00a0aim of\u00a0the\u00a0article was to illustrate the\u00a0methodology and to identify the\u00a0degree of\u00a0stress in\u00a0these zones based on the\u00a0comparison of\u00a0monthly groundwater abstractions with the\u00a0minimum monthly values of\u00a0the\u00a0baseflow, also in\u00a0relation to long-term hydrological characteristics (periods 1971\u20132000, 1981\u20132010, 1991\u20132020).<\/span><\/p>\n The\u00a0mentioned HGR are, in\u00a0most cases, evaluated as stressed over the\u00a0long term, indicating the\u00a0need for more careful management of\u00a0abstractions and protection of\u00a0water resources. Particular attention is given to HGR\u00a04522 and 4523, where excessive abstractions (occasionally even exceeding natural resource values) cause drying of\u00a0surface watercourses during drought. These impacts have led to a\u00a0revision of\u00a0abstraction limits, implementation of\u00a0routine monitoring, and adoption of\u00a0remedial measures based on the\u00a0results of\u00a0environmental impact assessments (EIA).<\/span><\/p>\n The article is set within the context of ongoing applied research (TA CR projects no. SS02030027, SS06010268, SQ01010176, SS01010208), which aim to refine knowledge of the hydrogeological environment, including redefinition of the boundaries of individual HGR, detailed clarification of the interaction between surface and groundwater, and identification of drought impacts on groundwater resources. Existing indications (e.g., results of tritium and other tracer analyses, residence-time calculations, and conceptual groundwater flow models) suggest that the boundaries of HGR 4410 and 4522 may be incorrectly delineated with respect to actual hydrogeological watersheds [15, 16], which could affect both the interpretation of balance results and planning of groundwater resource management. If partial sub-aquifers with distinct groundwater flow characteristics are identified within the previously assumed single hydrogeological aquifers, it is also a legitimate question whether separate groundwater balances should be carried out for each sub-aquifer. A combined balance encompassing several environments with mutually disconnected groundwater can distort the actual balance status. However, the actual implementation of separate balances for individual sub-aquifers depends on the availability of sufficient relevant input data. A balance analysis in a more detailed monthly step also proves to be very useful, as it provides a more precise view than the general annual analysis. If balance stress is confirmed at the monthly scale, a detailed hydrogeological assessment of the aquifer should follow from\u00a0<\/span>a\u00a0professional perspective, including a\u00a0hydraulic model of\u00a0groundwater flow, in\u00a0order to determine the\u00a0actual situation, identify the\u00a0problem, and explore possible remedies.<\/span><\/p>\n Overall, the\u00a0text emphasises the\u00a0need for a\u00a0thorough understanding of\u00a0the\u00a0hydrogeological environment (optimally based on mathematical modelling of\u00a0groundwater flow), the\u00a0requirement for continuous monitoring, assessment, and potential revision of\u00a0the\u00a0overarching conditions for groundwater abstraction, with a\u00a0focus on sustainable management and the\u00a0long-term protection of\u00a0water resources, as the\u00a0negative impacts of\u00a0climate change (reduced infiltration, declining water levels, and diminishing natural groundwater resources) are expected to become increasingly pronounced. Protecting groundwater quantity primarily means ensuring adequate protection of\u00a0infiltration areas (which must first be reliably identified) and adopting a\u00a0careful approach to managing groundwater abstractions, with a\u00a0preference for abstractions intended for drinking-water supply (Section 29 of\u00a0the\u00a0Water Act\u00a0[2]). The\u00a0conclusions of\u00a0the\u00a0article provide important guidance for groundwater management, setting of\u00a0abstraction permits, and overall strategic governance of\u00a0water resources under conditions of\u00a0climate change and increasing pressures on their use\u00a0[20, 21].<\/span><\/p>\n To conclude, it is worth noting that the\u00a0lower cost of\u00a0groundwater (compared with surface water) also has a\u00a0negative impact on management of\u00a0groundwater resources. The\u00a0price of\u00a0surface water in\u00a0Czech Republic is significantly higher than that of\u00a0groundwater, which often leads to preferential \u2013 and in\u00a0many places excessive and sometimes inappropriate \u2013 use of\u00a0groundwater instead of\u00a0surface water (for example, for purposes other than public water supply). Adjusting the\u00a0price of\u00a0groundwater abstraction could serve as a\u00a0significant economic instrument for the\u00a0protection of\u00a0available groundwater resources. Revenue generated from higher abstraction fees, if reinvested into further exploratory and monitoring activities focused on capture and infiltration areas, would greatly contribute to improving knowledge of\u00a0the\u00a0hydrogeological environment and the\u00a0long-term sustainable use and necessary protection of\u00a0groundwater throughout Czech Republic.<\/span><\/p>\n The article was supported by the Technology Agency of the Czech Republic through the funding of research project no. SS02030027 Water Systems and Water Management in the Czech Republic under Climate Change Conditions (Water Centre), carried out in 2020\u20132026; project no. SS06010268 Understanding, Quantification and Protection of Strategic Deep-Circulation Groundwater Resources of the Czech Cretaceous Basin in HGRs 4410 and 4522, carried out in 2023\u20132026; project no.\u00a0SQ01010176 Impacts of\u00a0Climate Change on Minimum Residual Flows in\u00a0the\u00a0Jizera River Network and on Groundwater Abstractions in\u00a0Its Vicinity, carried out in\u00a02025\u20132028; and also within\u00a0the\u00a0implementation of\u00a0results from project no.\u00a0SS01010208 Managed Groundwater Recharge as a\u00a0Tool to Mitigate the\u00a0Impacts of\u00a0Drought in\u00a0the\u00a0Czech Republic, carried out in\u00a02020\u20132023.<\/span><\/span><\/em><\/p>\n The\u00a0Czech version of\u00a0this article was peer-reviewed, the\u00a0English version was translated from the\u00a0Czech original by Environmental Translation Ltd.<\/p>\n","protected":false},"excerpt":{"rendered":" This article presents a comprehensive overview of the evolution of methodological approaches to groundwater balance assessment in Czechoslovakia and the Czech Republic from the 1960s to the present. It outlines the transition from a static evaluation of \u201cexploitable re-serves\u201d toward a dynamic, process-based concept, emphasizing regular comparisons between actual water abstraction and natural groundwa-ter resources. This shift includes the adoption of monthly assessment intervals and quantile characteristics of base flow, aligning with the requirements of both national legislation (especially Act no. 254\/2001 Coll., the Water Act) and European directives on water protection.<\/p>\n","protected":false},"author":8,"featured_media":36433,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86,92],"tags":[3926,3617,308,3210,3925,3924],"coauthors":[401,400],"class_list":["post-36580","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","category-main","tag-base-flow","tag-bohemian-cretaceous-basin","tag-groundwater","tag-hydrogeology","tag-natural-groundwater-resources","tag-water-management-balance"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/36580","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=36580"}],"version-history":[{"count":4,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/36580\/revisions"}],"predecessor-version":[{"id":36711,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/36580\/revisions\/36711"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/36433"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=36580"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=36580"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=36580"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=36580"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}INTRODUCTION<\/h2>\n
DEVELOPMENT OF\u00a0METHODOLOGICAL APPROACHES<\/h2>\n
History of\u00a0groundwater balance assessment<\/h3>\n
\n
Current water management balance of\u00a0groundwater<\/h3>\n
Groundwater abstraction records<\/h3>\n
Hydrogeological zoning<\/h3>\n
\n
![\"\"](\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2025\/10\/Hrabankova-fig-1.jpg\")
<\/a>\nFig. 1. Hydrogeological zones 1972\u00a0[9]<\/h6>\n
<\/a>\nFig. 2. Hydrogeological zones 2005\u00a0[11]<\/h6>\n
Procedure for calculating water management balance<\/h3>\n
<\/a>\nFig. 3. Assessment of balance stress of HGR base and upper layers for 2007\u20132023; HGR areas discussed in the following section are shown in green<\/h6>\n
RESULT: EXAMPLES OF BALANCE ASSESSMENT IN HYDROGEOLOGICAL ZONES OF THE BOHEMIAN CRETACEOUS BASIN<\/h2>\n
\n
HGR\u00a04410 Cretaceous of\u00a0the\u00a0Jizera River, right-bank part<\/h3>\n
<\/a>\nFig. 4. Annual characteristics for basic balance assessment of HGR 4410, including long-term reference periods 1971\u20132000, 1981\u20132010, and 1991\u20132020<\/h6>\n
<\/a> <\/span><\/p>\nFig. 5. Water management balance in a monthly step, 2007\u20132023 [17, 18]<\/span><\/h6>\n
4430 Cretaceous of\u00a0the\u00a0Jizera River, left-bank part<\/h3>\n
\n
\nrange), compared with the\u00a0previous two periods (1971\u20132000, 1981\u20132010),
\nclearly demonstrating the\u00a0long-term effects of\u00a0climate change.<\/span><\/p>\n<\/a>Fig. 6. Annual characteristics for basic balance assessment of HGR 4430, including long-term reference periods 1971\u20132000, 1981\u20132010, and 1991\u20132020<\/h6>\n<\/a>\n<\/a>\nFig. 7. Water management balance in a monthly step, 2007\u20132024 [17, 18]<\/h6>\n
4522 Cretaceous of\u00a0the\u00a0Lib\u011bchovka and P\u0161ovka Streams and 4523 Cretaceous of\u00a0the\u00a0Obrtka and \u00da\u0161t\u011bck\u00fd potok\u00a0Streams<\/h3>\n
<\/a> <\/span><\/p>\nFig. 8. Annual characteristics for basic balance assessment of HGR 4522, including long-term reference periods 1971\u20132000, 1981\u20132010, and 1991\u20132020<\/h6>\n
<\/a>\nFig. 9. Water management balance in a monthly step, 2007\u20132024 [17, 18]<\/h6>\n
<\/a>Fig. 10. Annual characteristics for basic balance assessment of HGR 4523, including long-term characteristic periods 1971\u20132000, 1981\u20132010, and 1991\u20132020<\/h6>\n<\/a><\/h6>\nFig.\u00a011. Processing of\u00a0water management balance in\u00a0a\u00a0monthly step \u2013 period 2007\u20132024\u00a0[17, 18]<\/span><\/h6>\n
DISCUSSION OF RESULTS<\/h2>\n
Hydrogeological zone 4410<\/h3>\n
Hydrogeological zone 4430<\/h3>\n
Hydrogeological zones 4522 and 4523<\/h3>\n
CONCLUSION<\/h2>\n
Acknowledgements<\/h3>\n