The\u00a0results show that restoration affects the\u00a0dynamics of\u00a0HS occurrence. In\u00a0surface and groundwater from the\u00a0restored site, higher minimum HS concentrations and greater annual variability were observed, whereas the\u00a0non-restored site showed lower minimum but higher maximum concentrations under dry hydrological conditions \u2013 when surface runoff and the\u00a0associated transport of\u00a0substances are minimal. The\u00a0ratio of\u00a0humic to fulvic acids (HA\/FA), important in\u00a0terms of\u00a0water treatment and chemical behaviour, was less favourable in\u00a0the\u00a0restored site, indicating a\u00a0higher proportion of\u00a0poorly degradable fulvic acids.<\/span><\/p>\n During significant rainfall-runoff events, HS concentrations decreased, but the\u00a0overall volume of\u00a0mobilized organic matter increased. The\u00a0study also demonstrated a\u00a0notable self-purifying effect of\u00a0the\u00a0recipient stream, which reduced occasional higher HS concentrations from restored sites, and a\u00a0positive effect of\u00a0the\u00a0retention reservoir on water chemistry, with reduced peak HS concentrations and an increased HA\/FA ratio at the\u00a0outflow.<\/span><\/p>\n The\u00a0findings provide valuable insights for planning water management measures in\u00a0peatland areas and help to clarify the\u00a0dynamics of\u00a0organic substances within\u00a0peat bogs and their drainage systems. The\u00a0results may contribute to improving the\u00a0quality of\u00a0water sources when planning restoration efforts in\u00a0peatlands affected by peat extraction.<\/span><\/p>\n The\u00a0hydrological significance of\u00a0mountain\u00a0peatlands has long been debated, particularly regarding their contribution to the\u00a0hydrological regime. This includes their role in\u00a0retaining water during periods of\u00a0high precipitation, supporting base flow in\u00a0streams during dry periods, and influencing water chemistry through peatland restoration. Restoration typically involves blocking drainage channels, which were originally created to drain\u00a0the\u00a0peatland for peat extraction. Expert opinions on the\u00a0influence of\u00a0peatlands on the\u00a0hydrological regime of\u00a0catchments are contradictory; for example, study\u00a0[1] highlights the\u00a0benefits of\u00a0peatlands and their restoration in\u00a0stabilising the\u00a0hydrological regime in\u00a0the\u00a0\u0160umava region. In\u00a0contrast, study\u00a0[2] finds no significant contribution of\u00a0peatlands to water retention or the\u00a0maintenance of\u00a0water supplies during dry periods in\u00a0the\u00a0same region. To monitor these hydrological and, in\u00a0particular, hydrochemical processes, and to clarify some disputed hypotheses, a\u00a0comprehensive monitoring programme was initiated in\u00a0the\u00a0Ore Mountains peatlands near the\u00a0village of\u00a0Hora Svat\u00e9ho \u0160ebesti\u00e1na. The\u00a0monitoring covers both quantitative and qualitative aspects of\u00a0hydrology. This paper focuses on the\u00a0results describing the\u00a0content of\u00a0humic substances (HS) in\u00a0surface and subsurface waters in\u00a0both restored and non-restored parts of\u00a0the\u00a0peatland.<\/span><\/p>\n The\u00a0study area comprises two experimental sites, A\u00a0and B (Fig.\u00a01<\/span><\/em>), located in\u00a0the\u00a0central part of\u00a0the\u00a0Ore Mountains, southwest of\u00a0the\u00a0village of\u00a0Hora Svat\u00e9ho \u0160ebesti\u00e1na, at an altitude of\u00a0850\u2013895\u00a0m a.s.l. Both sites are peatlands with a\u00a0history of\u00a0completed peat extraction, which left drainage channels that artificially lowered the\u00a0groundwater level. These channels are currently being gradually restored through the\u00a0construction of\u00a0weirs, aimed at returning the\u00a0hydrological regime to a\u00a0state closer to natural conditions. Site A\u00a0covers approximately 0.4 km\u00b2 and is characterised mainly by sparse dwarf pine and spruce stands in\u00a0the\u00a0peripheral areas, which transition into grassland. Site B occupies roughly 1 km\u00b2 and exhibits a\u00a0more diverse structure, spanning two hydrological catchments: the\u00a0Chomutovka River to the\u00a0north and the\u00a0Prun\u00e9\u0159ovsk\u00fd Stream to the\u00a0south. At the\u00a0edge of\u00a0site B lies Novovesk\u00fd Pond, with an area of\u00a03.86\u00a0ha, which historically served as a\u00a0water reservoir for the\u00a0Chomutovka River. At\u00a0present, the\u00a0area is a\u00a0valuable habitat providing refuge for protected animal species. A\u00a0particular feature of\u00a0the\u00a0site is the\u00a0Chomutovka diversion channel, which supplements the\u00a0natural flow of\u00a0the\u00a0Chomutovka River with water from the\u00a0\u010cern\u00e1 River catchment. The\u00a0diversion passes through both study sites and alters the\u00a0natural runoff patterns, although its current function is limited due to its reconnection to the\u00a0\u010cern\u00e1 River.<\/span><\/p>\n The\u00a0geological substrate consists of\u00a0rocks of\u00a0the\u00a0Ore Mountains crystalline complex, specifically paragneisses, orthogneisses, and amphibolites, with occurrences of\u00a0skarns. Overlying these are Quaternary sediments, predominantly clayey and peat-rich. From a\u00a0hydrogeological perspective, the\u00a0area is a\u00a0fractured-rock aquifer with very low permeability peat layers, which act as a\u00a0natural barrier.<\/span><\/p>\n From a\u00a0pedological perspective, the\u00a0area is predominantly covered by modal podzols, with gley soils and histosols occurring in\u00a0permanently waterlogged locations. According to Quitt, the\u00a0climate falls within\u00a0the\u00a0mountainous CH6 region, characterised by a\u00a0long, wet winter and a\u00a0short, cool summer.<\/span><\/p>\n The\u00a0site is located within\u00a0the\u00a0Ore Mountains protected area of\u00a0natural water accumulation (CHOPAV) and lies close to the\u00a0protection zones of\u00a0groundwater sources supplying the\u00a0village of\u00a0Hora Svat\u00e9ho \u0160ebesti\u00e1na. Historically, the\u00a0area has been affected by mining activities, particularly remnants of\u00a0ore extraction from the\u00a014th\u201317th centuries. These features may locally influence the\u00a0hydrological regime.<\/span><\/p>\n HS, particularly humic and fulvic acids, are the\u00a0main\u00a0components of\u00a0dissolved organic matter (DOM), which is released in\u00a0significant amounts from peatlands into surface and groundwater. These substances have a\u00a0complex macromolecular structure rich in\u00a0aromatic and functional oxygen groups\u00a0[3], giving them a\u00a0high affinity for forming complexes with metals (e.g., Fe, Al, Cu) and the\u00a0ability to influence the\u00a0transport of\u00a0toxic substances in\u00a0the\u00a0environment. From the\u00a0perspective of\u00a0drinking water treatment, HS pose a\u00a0significant problem: during chlorination, they can react with disinfectants (particularly chlorine compounds) to form disinfection by-products, many of\u00a0which (e.g., trihalomethanes) are carcinogenic [4, 5]. In\u00a0addition, they increase the\u00a0need for coagulants and adsorbents during water treatment\u00a0[6], reduce filtration efficiency, and can negatively affect the\u00a0taste and smell of\u00a0water\u00a0[7]. In\u00a0areas with peatlands, particularly during periods of\u00a0high flow, the\u00a0concentration of\u00a0dissolved organic carbon (DOC) in\u00a0raw water sources fluctuates, complicating the\u00a0technological stability of\u00a0treatment plants and increasing operational costs\u00a0[8].<\/span><\/p>\n In\u00a0the\u00a0Ore Mountains, the\u00a0occurrence and behaviour of\u00a0HS in\u00a0peatlands have been investigated in\u00a0several significant studies, with attention given both to natural factors (hydrological regime, botanical composition) and to the\u00a0influence of\u00a0anthropogenic acidification and land-use changes. Pokorn\u00fd et al. analysed the\u00a0long-term development of\u00a0peatlands using palaeoecological methods, including the\u00a0impact of\u00a0climatic extremes on the\u00a0accumulation and transformation of\u00a0organic matter\u00a0[9]. Charamba et al. mapped the\u00a0chemical composition of\u00a0water in\u00a0peatlands across central Europe, including sites in\u00a0the\u00a0Ore Mountains, and demonstrated that the\u00a0local raised bogs have a\u00a0high proportion of\u00a0aromatic DOM fractions with low biodegradability\u00a0[10]. Studies from the\u00a0Bo\u017e\u00ed Dar and C\u00ednovec peatlands further show that following drought episodes and subsequent rewetting, there is a\u00a0pronounced pulsed release of\u00a0DOC into receiving waters, confirming the\u00a0sensitivity of\u00a0these systems to climatic extremes\u00a0[11]. Some studies have also demonstrated a\u00a0relationship between fulvic acid concentration and increased iron mobility, which has a\u00a0direct impact on eutrophication and the\u00a0water chemistry of\u00a0adjacent streams\u00a0[12]. These findings are crucial not only for the\u00a0ecological protection of\u00a0peatland ecosystems but also for the\u00a0optimisation of\u00a0water management measures in\u00a0catchments with a\u00a0significant proportion of\u00a0wetland areas.<\/span><\/p>\n Monitoring of\u00a0the\u00a0peatlands in\u00a0sites A\u00a0and B was designed as a\u00a0comprehensive system to observe hydrological and climatic conditions in\u00a0an environment altered by historical peat extraction. The\u00a0overall aim of\u00a0the\u00a0monitoring is to evaluate the\u00a0effectiveness of\u00a0restoration measures, which involve the\u00a0construction of\u00a0weirs to retain\u00a0water and raise groundwater levels, and to assess their impact on changes in\u00a0the\u00a0chemistry of\u00a0surface and groundwater, with a\u00a0focus on the\u00a0occurrence of\u00a0organic substances. Restoration in\u00a0the\u00a0form of\u00a0blocking drainage channels has already been completed across almost the\u00a0entire area of\u00a0site A. In\u00a0contrast, site B remains largely in\u00a0a\u00a0pre-restoration state, and manual sampling is focused in\u00a0these areas. As part of\u00a0the\u00a0monitoring, wells, flow weirs, meteorological stations, and automatic samplers were installed at both sites, allowing observation of\u00a0the\u00a0status and chemistry of\u00a0surface and groundwater, precipitation, temperature, air humidity, and snow water equivalent. For the\u00a0evaluation of\u00a0HS occurrence, the\u00a0part of\u00a0the\u00a0monitoring network focused on water chemistry was used. The\u00a0other measurement points served, among other purposes, to monitor background processes associated with the\u00a0dynamics of\u00a0organic substances in\u00a0surface and groundwater.<\/span><\/p>\n For the\u00a0comprehensive monitoring of\u00a0site A\u00a0(Fig.\u00a02<\/span><\/em>), the\u00a0existing well network of\u00a0series P, PA, and PV was used, in\u00a0which groundwater level, temperature, and conductivity are measured manually twice a\u00a0year. In\u00a0addition, wells of\u00a0series D1 to D5 were installed, equipped with pressure sensors for continuous measurement of\u00a0groundwater level and temperature. Selected wells, such as D2 and D5, were installed as paired wells \u2013 one penetrating only the\u00a0upper peat layer (acrotelm), while the\u00a0other reached the\u00a0lower peat layer (catotelm). Wells D1 and D3 also serve for monthly water sampling for laboratory chemical analyses.<\/span><\/p>\n Site A\u00a0contains four flow weirs: V1-CH5, located at the\u00a0eastern edge with a\u00a0triangular profile (so-called Thomson weir); V2, in\u00a0the\u00a0west, equipped with a\u00a0circular weir and built directly into the\u00a0dam structure; V3, situated in\u00a0the\u00a0southeastern part, which drains water from the\u00a0forested area; and V1-CH1, located approximately 400\u00a0m west of\u00a0profile V2, which serves exclusively as a\u00a0reference point for manual surface water sampling without continuous measurement. All weirs are equipped with sensors for measuring water level, temperature, conductivity, and pH, and weirs V3 and V1-CH5 are used for surface water sampling.<\/p>\n Hydrological monitoring in\u00a0site B (Fig.\u00a03<\/span><\/em>) was considerably expanded. Fifty-five shallow wells of\u00a0series B, with a\u00a0maximum depth of\u00a03\u00a0m, were installed in\u00a0a\u00a0regular grid covering both restored and non-restored parts of\u00a0the\u00a0peatland. In\u00a0addition, wells of\u00a0series D8 to D18 were installed, with D11, D14, and D16 also set up as paired wells to compare water levels between the\u00a0acrotelm and catotelm. Wells D8, D14, and D16 are also used for water sampling and chemical analysis. This observation network provides detailed information on the\u00a0hydrological conditions across the\u00a0peatland.<\/span><\/p>\n Surface waters in\u00a0site B are monitored through several flow weirs. Weir V4, in\u00a0the\u00a0western part, is equipped with a\u00a0rectangular notch and it monitors inflow from the\u00a0area below Jelen\u00ed hora. V5 is located on the\u00a0Chomutovka diversion channel and is fitted with an ultrasonic sensor. Weir V6, situated on the\u00a0Chomutovka River, is located at the\u00a0last weir before the\u00a0inflow into Novovesk\u00fd Pond and is used for sampling. For sampling the\u00a0Chomutovka River below the\u00a0pond, profile CH10 is used downstream of\u00a0the\u00a0safety weir, where manual hydrometric measurements are conducted.<\/p>\n Meteorological stations are installed at both sites. In\u00a0site A, a\u00a0basic station records air temperature, humidity, and precipitation. In\u00a0site B, a\u00a0comprehensive climatological station additionally measures wind speed and direction, solar radiation, soil heat flux, and soil moisture. For year-round precipitation measurements, a\u00a0heated rain\u00a0gauge was installed in\u00a0the\u00a0village of\u00a0Hora Svat\u00e9ho \u0160ebesti\u00e1na, which also serves to trigger automatic samplers during rainfall events.<\/p>\n Groundwater samples are collected monthly from selected wells of\u00a0series D. These include wells D1-CH2 and D3-CH3 in\u00a0site A, and wells D8-CH6, D14-CH7, and D16-CH8 in\u00a0site B. Sampling was always scheduled at the\u00a0end of\u00a0each month, taking care to ensure stable and consistent meteorological and hydrological conditions. This means that no significant hydrometeorological extremes occurred during or immediately before sampling that could have temporarily affected groundwater quality. Samples are transported to the\u00a0VZlab laboratory, where the\u00a0following parameters are determined:<\/p>\n Chemical oxygen demand (COD-Mn), N\u2013NO\u2083–<\/sup>, N\u2013NO\u2082–<\/sup>, N\u2013NH\u2084+<\/sup>, total nitrogen (Nt<\/sub>), SO4<\/sub>2-<\/sup>, total phosphorus (Pt<\/sub>), Fe, Al (dissolved and particulate), DOC, A\u2082\u2085\u2084, (A\u2082\u2085\u2084\/DOC)*100, total hardness (TH), HS, humic acids, and fulvic acids.<\/p>\n Surface water samples are collected monthly together with groundwater sampling. The\u00a0same rule applies: sampling is always conducted at the\u00a0end of\u00a0the\u00a0month under as stable hydrometeorological conditions as possible. Sampling is carried out at weirs V1-CH5 (restored catchment), V3-CH4, and V7-CH1 (forest non-restored catchment) in\u00a0site A, and in\u00a0site B at weir V6-CH9 (Fig.\u00a04<\/em>) and at sampling site CH10 downstream of\u00a0the\u00a0safety flow weir of\u00a0Novovesk\u00fd Pond (non-restored catchment, Fig.\u00a06<\/em>). The\u00a0current flow in\u00a0the\u00a0watercourse is recorded during sampling. Sampling sites V7-CH1 and CH10 do not have continuous water level measurements, therefore flows at the\u00a0time of\u00a0sampling are measured and calculated on site. At profile V7-CH1, a\u00a0flow weir was installed for this purpose. At profile CH10, hydrometric measurements are conducted during sampling. Samples are then transported to the\u00a0VZlab laboratory, where the\u00a0following parameters are determined:<\/p>\n COD-Mn, N\u2013NO\u2083–<\/sup>, N\u2013NO\u2082–<\/sup>, N\u2013NH\u2084+<\/sup>, Nt<\/sub>, SO4<\/sub>2-<\/sup>, Pt<\/sub>, Fe, Al (dissolved and particulate), DOC, A\u2082\u2085\u2084, (A\u2082\u2085\u2084\/DOC)*100, TH, HS, humic acids, and fulvic acids.<\/p>\n The number of samples collected depends on hydrological conditions. During dry periods or generally in the summer months, groundwater levels may fall below the depth of the wells, and watercourses may dry out, making\u00a0<\/span>sampling impossible. For each groundwater and surface water sample, supplementary measurements of\u00a0conductivity and water pH are performed using an\u00a0Aquatroll 500\u00a0multiparameter probe.<\/span><\/p>\n Samples are also collected using ISCO 6712 automatic samplers at profiles V4 and V5 (Fig.\u00a010<\/span><\/em>), designed to capture the\u00a0chemical response of\u00a0the\u00a0watercourse to rainfall events. The\u00a0parameters determined are the\u00a0same as for manual sampling. Sampling is synchronous: when a\u00a0hydrological event is anticipated, the\u00a0sampler at V5 is activated via SMS. The\u00a0V5 sampler is locally linked to the\u00a0sampler at V4, which is outside stable GSM coverage, so V4 is triggered at the\u00a0same time. A\u00a0total of\u00a024 samples are collected at two-hour intervals, of\u00a0which 10 are selected for analysis, ideally covering the\u00a0watercourse\u2019s\u00a0response to precipitation. The\u00a0reach between the\u00a0two samplers is approximately 600\u00a0m long, receiving water from a\u00a0single already restored area in\u00a0site B, and the\u00a0aim is to capture any chemical changes along this section.<\/span><\/p>\n The\u00a0following results are based on two years of\u00a0monthly sampling. Of\u00a0all the\u00a0chemical parameters observed, this article focuses on HS and related indicators of\u00a0the\u00a0presence of\u00a0organic matter in\u00a0water (the\u00a0ratio of\u00a0humic to fulvic acids \u2013 HA\/FA, dissolved organic carbon \u2013 DOC, and absorbance at 254\u00a0nm\u00a0\u2013 A\u2082\u2085\u2084). Fig.\u00a05<\/span><\/em> shows the\u00a0results for groundwater and surface water sampling sites CH1\u2013CH10. Sites (wells) CH2 and CH6 were excluded from the\u00a0evaluation because of\u00a0the\u00a0very low number of\u00a0samples obtained, due to the\u00a0absence of\u00a0water in\u00a0the\u00a0wells. The\u00a0results show seasonality in\u00a0the\u00a0HS content of\u00a0surface waters, with concentrations increasing during summer low-flow conditions. In\u00a0contrast, groundwater does not exhibit such pronounced fluctuations and no clear seasonality is apparent. Only well CH7 recorded three higher values, but these were measured at very low groundwater levels, which may have resulted in\u00a0the\u00a0sampling of\u00a0sediment from the\u00a0well bottom. In\u00a0general, groundwater shows higher HS concentrations throughout the\u00a0year, except in\u00a0summer months, when surface water displays elevated concentrations not only of\u00a0organic substances but, according to the\u00a0analyses, also of\u00a0metals (Fe, Al) and total nitrogen\u00a0[13]. Other indicators linked to the\u00a0presence of\u00a0organic matter in\u00a0water (DOC and A\u2082\u2085\u2084) exhibit similar patterns. Comparing concentration dynamics in\u00a0surface water from restored (CH5) and non-restored sites (CH9 and CH10), profile CH5 shows higher minimum HS concentrations and overall greater variability during the\u00a0year, while summer maxima are lower. By contrast, profile CH9\u00a0maintains consistently lower winter minima, but in\u00a0summer reaches up to twice the\u00a0HS concentrations. This results in\u00a0fairly balanced average values over the\u00a0entire monitoring period (Tab.\u00a01<\/span><\/em>): CH5 \u2013 41.5\u00a0mg\/l, CH9 \u2013 40.7\u00a0mg\/l. However, discharge during sampling has a\u00a0significant influence on the\u00a0total export of\u00a0organic matter. The\u00a0highest discharges usually occur in\u00a0winter during snowmelt. While concentrations at profile CH9 during this period remain\u00a0below 25\u00a0mg\/l, those at CH5 are up to twice as high. Conversely, higher concentrations at CH9 are recorded under very low discharges of\u00a0around 1\u00a0l\/s\u00a0or less. This results in\u00a0a\u00a0greater overall export of\u00a0organic substances from the\u00a0restored site. However, in\u00a0comparison with the\u00a0non-restored site, the\u00a0higher concentrations in\u00a0the\u00a0restored site are reached even at higher discharges and during wetter periods, when the\u00a0load of\u00a0HS in\u00a0the\u00a0stream is quickly diluted by additional inflows with lower HS content. According to analyses carried out as part of\u00a0a\u00a0concurrently prepared bachelor thesis\u00a0[14], concentrations of\u00a0HS decreased by more than 80% along an approximately 5 km section of\u00a0the\u00a0Chomutovka Stream. To reduce the\u00a0influence of\u00a0occasionally occurring extreme values, Tab.<\/span>\u00a02<\/em> presents the\u00a0median concentrations for each site: CH5 \u2013 32\u00a0mg\/l and CH9\u00a0\u2013 15\u00a0mg\/l.<\/span><\/p>\n For groundwater, higher HS concentrations are recorded for most of\u00a0the\u00a0year at well CH3 in\u00a0the\u00a0restored site. The\u00a0overall average is highest at CH7, but this is due to the\u00a0three previously mentioned outlying values. However, considering the\u00a0median concentrations, well CH7\u00a0has similar HS levels to CH8, which is located in\u00a0a\u00a0drained but relatively intact part of\u00a0the\u00a0peatland and exhibits the\u00a0lowest HS concentrations. The\u00a0highest median concentration is observed at well CH3 in\u00a0the\u00a0restored site.<\/span><\/p>\n Water quality is affected not only by HS concentrations but also by the ratio of humic to fulvic acids (HA\/FA). A higher proportion of fulvic acids negatively impacts drinking water treatment because they are more soluble and more difficult to remove. The HA\/FA values are close to zero and only occasionally exceed 1. No seasonality is apparent, and each series contains one or two outliers that are unrelated to water level or season. Therefore, conclusions are\u00a0<\/span>based on the\u00a0median values shown in\u00a0Tab.<\/span>\u00a02<\/em>. The\u00a0lowest HA\/FA ratio, and thus the\u00a0highest proportion of\u00a0more persistent fulvic acids, occurs in\u00a0the\u00a0restored part of\u00a0site A, specifically at sampling sites CH5 and CH3. By contrast, the\u00a0highest values were recorded at the\u00a0profile draining the\u00a0forested area (CH1), at well CH8 in\u00a0the\u00a0non-restored site, and at profile CH10 at the\u00a0reservoir outflow.<\/span><\/p>\n During the\u00a0monitoring period, a\u00a0significant rainfall-runoff event was recorded using automatic samplers from 13 to 15 September 2024. The\u00a0samplers were synchronously activated before the\u00a0onset of\u00a0the\u00a0runoff response and collected samples at 2-hour intervals over a\u00a0period of\u00a040 hours. To capture both the\u00a0rising and falling stages of\u00a0the\u00a0water level, 10 samples were selected for analysis at 4-hour intervals. The\u00a0results shown in\u00a0Figs. 7<\/em> and 8<\/em> indicate a\u00a0similar pattern of\u00a0change in\u00a0HS and DOC concentrations. At the\u00a0start of\u00a0the\u00a0event, concentrations are high, and as discharge increases, they decrease during the\u00a0first 12 hours to values that remain\u00a0relatively stable thereafter, even though discharge continues to rise significantly. This pattern is consistent for both sampling profiles, even though channels from the\u00a0restored part of\u00a0site B discharge into the\u00a0stream between them. HS concentrations also decrease by almost half between the\u00a0sampling sites. The\u00a0HA\/FA ratio between the\u00a0samplers increases, particularly during the\u00a0peak of\u00a0the\u00a0event. No increase in\u00a0HS concentrations caused by inflow from the\u00a0restored site was observed between profiles V4 and V5. When HS concentrations are converted to the\u00a0total exported mass, the\u00a0results are given in\u00a0Tab.\u00a03<\/em>. At the\u00a0start of\u00a0the\u00a0event, under the\u00a0lowest discharge and highest concentration, HS export was 258.3\u00a0mg\/s. By contrast, immediately before the\u00a0peak, HS concentrations are still decreasing, and export reaches 12,650.1\u00a0mg\/s. At the\u00a0peak, it declines to 7,628\u00a0mg\/s. HS concentrations then gradually increase; however, the\u00a0decreasing discharge causes a\u00a0slow decline in\u00a0exported HS mass. Over the\u00a040-hour monitoring period, approximately 771\u00a0kg of\u00a0HS were exported through the\u00a0profile. This topic is also addressed in\u00a0the\u00a0bachelor\u2019s\u00a0thesis\u00a0[15].<\/p>\n Given the\u00a0increase in\u00a0discharge between the\u00a0two profiles, it can be assumed that the\u00a0stream also receives a\u00a0substantial contribution from the\u00a0non-restored site. In\u00a0this case, a\u00a0precise delineation of\u00a0the\u00a0catchment and source areas for each sampler profile would be beneficial. However, this is essentially impossible because the\u00a0stream itself is an artificially constructed channel crossing natural watercourses and is connected to a\u00a0network of\u00a0drainage channels, which overflow into other drainage paths during higher flows.<\/p>\n The\u00a0positive effect of\u00a0Novovesk\u00fd Pond on stream water chemistry is already evident from the\u00a0results shown in\u00a0Tab.\u00a01<\/em>, Tab.\u00a02<\/em>, and Fig.\u00a05<\/em>. Fig.\u00a09<\/em> illustrates the\u00a0percentage change in\u00a0concentrations of\u00a0all monitored substances between profile CH9 above the\u00a0reservoir and profile CH10 below it. Decreases were observed for DOC, aluminium, absorbance, chemical oxygen demand determined by permanganate (CODmn<\/sub>), conductivity, total phosphorus, total nitrogen, and sulphates. An increase in\u00a0pH and the\u00a0ratio of\u00a0humic to fulvic acids (HA\/FA), reflecting a\u00a0higher proportion of\u00a0humic acids, can also be considered beneficial. Acid neutralising capacity (ANC\u2084.\u2085) was also increased, most likely as a\u00a0result of\u00a0the\u00a0higher pH.<\/p>\n A\u00a0slight increase in\u00a0undesirable parameters was observed for dissolved iron concentrations. Although DOC values are low, the\u00a0higher pH creates more favourable conditions for the\u00a0release of\u00a0metals into the\u00a0water column. The\u00a0increase in\u00a0pH is also associated with higher bicarbonate concentrations. Values of\u00a0the\u00a0indicator (A\u2082\u2085\u2084\/DOC) * 100 are elevated, reflecting both the\u00a0higher proportion of\u00a0humic acids and the\u00a0decomposition of\u00a0organic matter accumulated on the\u00a0reservoir bottom.<\/p>\n Probable mechanisms contributing positively to HS content and the HA\/FA ratio include exposure to sunlight, which induces photodegradation and reduces the\u00a0molecular weight of\u00a0humic acids. Microbial activity and the\u00a0presence of\u00a0iron and aluminium also play a\u00a0role, facilitating complexation and the\u00a0coagulation of\u00a0HS into sediments [16, 17]. The\u00a0transformative effect of\u00a0the\u00a0reservoir is also significant, as it dilutes higher concentrations entering from the\u00a0inflow to lower levels. Consequently, in\u00a0the\u00a0stream below the\u00a0reservoir, minimum concentrations of\u00a0chemical parameters are higher compared with the\u00a0inflow, while maximum values, typical of\u00a0the\u00a0water entering the\u00a0reservoir, are substantially reduced.<\/p>\n The\u00a0effect of\u00a0peatland restoration on HS content in\u00a0groundwater and surface water cannot be generalised, as each hydrological system within\u00a0a\u00a0peatland may respond differently. For example, study\u00a0[18] reports a\u00a0long-term increase in\u00a0organic matter concentrations in\u00a0water. In\u00a0contrast, other studies document a\u00a0sudden increase in\u00a0concentrations immediately following restoration, followed by a\u00a0decline, although values remain\u00a0higher than the\u00a0original levels [19, 20]. Some studies, on the\u00a0other hand, report no changes in\u00a0organic matter concentrations [21, 22]. There are even studies documenting a\u00a0decrease in\u00a0organic matter concentrations following the\u00a0damming of\u00a0drainage channels and an increase in\u00a0groundwater level [23\u201325]. For example, study\u00a0[23] attributes the\u00a0decline in\u00a0HS concentration to the\u00a0elevated groundwater level, which dilutes concentrations throughout the\u00a0peatland. However, higher degrees of\u00a0wetness are generally cited as a\u00a0reason for increased export of\u00a0organic matter.<\/span><\/p>\n Study\u00a0[26] in\u00a0the\u00a0Kameni\u010dka and Fl\u00e1je catchments also examined the\u00a0relationship between organic matter content, precipitation, and discharge, reporting the\u00a0highest export of\u00a0substances 1\u20132 days after rainfall. In\u00a0our study area, where we focused primarily on the\u00a0peak flow period, concentrations of\u00a0the\u00a0monitored substances increased immediately at the\u00a0onset of\u00a0the\u00a0rising water level or were followed directly by a\u00a0decrease due to dilution by rainwater. However, as shown by calculations of\u00a0total exported mass, a\u00a0much larger quantity of\u00a0organic matter is transported during periods of\u00a0lower concentration combined with higher discharge than during low discharge and high concentrations. The\u00a0study also describes a\u00a0positive effect of\u00a0the\u00a0reservoir on organic matter concentrations. However, this is probably primarily due to the\u00a0temporal transformation of\u00a0higher concentrations at the\u00a0inflow, as observed for Novovesk\u00fd Pond. For example, the\u00a0study reports the\u00a0largest measured differences during periods of\u00a0minimal discharge, when the\u00a0total mass balance of\u00a0substances is negligible. In\u00a0contrast, during higher flows, concentrations at the\u00a0reservoir outflow may exceed those at the\u00a0inflow. Finally, the\u00a0study confirms findings related to self-purification processes in\u00a0the\u00a0stream, which we also observed in\u00a0the\u00a0Chomutovka River.<\/span><\/p>\n The\u00a0above results highlight the\u00a0importance of\u00a0site-specific research, which provides a\u00a0comprehensive insight into hydrological processes and the\u00a0effectiveness of\u00a0remedial measures implemented locally. They also indicate that the\u00a0hydrochemical behaviour of\u00a0these human-impacted wetland catchments is highly variable, whether due to the\u00a0age and nature of\u00a0the\u00a0restorations themselves or the\u00a0morphology of\u00a0the\u00a0catchment. Consequently, findings from such sites are valuable, but their transferability is limited. Data from this monitoring will therefore be further applied in\u00a0locally focused projects, such as the\u00a0RUR:\u00a0Region to University, University to Region<\/span> CZ.10.02.01\/00\/22_002\/0000210 project, which addresses conditions in\u00a0the\u00a0\u00dast\u00ed nad Labem Region.<\/span><\/p>\n Hydrological monitoring of\u00a0peatland habitats, ongoing since December 2022 in\u00a0the\u00a0Prameni\u0161t\u011b Chomutovky nature reserve, focuses on hydrological and hydrochemical processes in\u00a0restored and non-restored sites affected by peat extraction. The\u00a0project is conducted under a\u00a0public procurement for the\u00a0\u00dast\u00ed nad Labem Region and provides results with significance extending beyond the\u00a0Chomutovka catchment, as it represents a\u00a0source area with higher demands on water quality for drinking water supply. The\u00a0aim is to maintain\u00a0long-term monitoring at the\u00a0site, focused on evaluating the\u00a0impacts of\u00a0restoration on both quantitative and qualitative hydrology. This article presents only a\u00a0portion of\u00a0the\u00a0monitoring results, specifically those related to the\u00a0assessment of\u00a0HS in\u00a0surface and groundwater. The\u00a0overall monitoring will continue at least until the\u00a0end of\u00a02025, providing an opportunity to present broader conclusions.<\/span><\/p>\n Monitoring of HS concentrations in the peatlands of the study area near Hora Svat\u00e9ho \u0160ebesti\u00e1na shows higher concentrations in the restored site, where drainage channels were dammed and the groundwater level increased. While concentrations in wells fluctuate within a similar range throughout the year, even during summer declines in groundwater level, surface waters exhibit a marked increase in concentrations at low flow rates. However, due to the low flow, the amount of exported organic matter at that time is small. This amount increases during runoff events in response to significant rainfall, even\u00a0<\/span>though HS concentrations decrease under these conditions. Based on observations from streams draining the\u00a0peatlands, it can be concluded that even occasional elevated concentrations of\u00a0HS from restored or non-restored sites do not have a\u00a0significant impact on water quality in\u00a0the\u00a0Chomutovka Stream itself. Self-purification and dilution processes cause a\u00a0rapid decrease in\u00a0HS and DOC concentrations, as shown by results from automatic samplers installed 500\u00a0m apart, and also along approximately 5 km of\u00a0the\u00a0Chomutovka Stream, where HS concentrations decrease by more than 80\u00a0%.<\/span><\/p>\n As an appropriate measure to improve water quality and prevent short-term occurrences of\u00a0elevated concentrations of\u00a0substances that degrade water quality, the\u00a0installation of\u00a0a\u00a0reservoir at the\u00a0outflow from the\u00a0peatland area appears beneficial. Within\u00a0the\u00a0monitoring, water chemistry was observed at profile CH9 at the\u00a0reservoir inflow and at profile CH10 at the\u00a0reservoir outflow. For HS, a\u00a0temporal transformation of\u00a0concentrations was observed, with a\u00a0marked reduction in\u00a0maximum values and a\u00a0corresponding increase in\u00a0minimum values, as accumulated HS are gradually released from the\u00a0reservoir. This process is expected, but it is also accompanied by an increase in\u00a0the\u00a0HA\/FA ratio at the\u00a0outflow, indicating that more undesirable fulvic acids undergo decomposition or sedimentation within\u00a0the\u00a0reservoir. Additionally, pH and the\u00a0ANC\u2084.\u2085 and BNC\u2084.\u2085 parameters increase, contributing to improved biological stability.<\/span><\/p>\n This article is based on monitoring conducted within\u00a0the\u00a0project Hydrological Monitoring of\u00a0Peatland Habitats 2022\u20132024, funded by the\u00a0\u00dast\u00ed nad Labem Region under a\u00a0contract for work. The\u00a0article also draws on knowledge and experience from monitoring carried out for project no. SS02030027, Water Systems and Water Management in\u00a0the\u00a0Czech Republic under Climate Change (Water Centre), which is also applied in\u00a0the\u00a0project RUR: Region to the\u00a0University, University to the\u00a0Region CZ.10.02.01\/00\/22_002\/0000210. In\u00a0collaboration with UJEP and CZU, two bachelor\u2019s\u00a0theses were completed, focusing on HS and the\u00a0retention capacity of\u00a0the\u00a0peatland.<\/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.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":" This article focuses on evaluating the concentrations of humic substances (HS) in peatland waters in the Ore Mountains region, specifically in the area near the village of Hora Svat\u00e9ho \u0160ebesti\u00e1na in the Prameni\u0161t\u011b Chomutovky nature reserve. The aim was to assess the impact of restoration measures on the occurrence of HS in surface and subsurface waters in a post-peat-extraction environment. Monitoring was carried out from 2022 to 2024 on two experimental sites \u2013 one restored (site A) and one predominantly non-restored (site B) \u2013 and involved extensive monthly sampling, installation of flow weirs, shallow observation wells, and meteorological stations.<\/p>\n","protected":false},"author":8,"featured_media":36511,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86,93],"tags":[3929,1793,2450,3927,3928],"coauthors":[2889,846,331],"class_list":["post-36707","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","category-two-articles","tag-humic-substances","tag-hydrochemistry","tag-hydrology","tag-peat-bog","tag-revitalization"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/36707","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=36707"}],"version-history":[{"count":3,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/36707\/revisions"}],"predecessor-version":[{"id":36710,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/36707\/revisions\/36710"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/36511"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=36707"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=36707"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=36707"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=36707"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}INTRODUCTION<\/h2>\n
Description of\u00a0the\u00a0Study Area<\/h3>\n
![\"\"](\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2025\/10\/Vokoun-fig-1.jpg\")
<\/a>\nFig. 1. Schematic diagram of monitoring sites A and B (site A on the left corresponds to the watershed for profile V1-CH1, see Fig. 2<\/em>); in many cases, the Chomutovka watershed does\u00a0not respect the slope conditions of the catchment area due to drainage channels, therefore, the watershed is based to a certain extent on field surveys and subsequent expert estimates<\/h6>\n
Humic substances in\u00a0peatlands<\/span><\/h3>\n
METHODOLOGY<\/h2>\n
Monitoring<\/h3>\n
<\/a>\nFig. 2. Monitoring facilities in\u00a0site A<\/h6>\n
<\/a><\/h6>\nFig. 3. Monitoring facilities in\u00a0site B<\/h6>\n
Groundwater<\/h3>\n
Surface water<\/h3>\n
<\/a><\/h6>\nFig. 4. Measurement of chemical parameters of surface water at profile V6-CH9<\/h6>\n
<\/a>Fig. 5. Results of\u00a0chemical analyses of\u00a0selected parameters<\/h6>\n<\/a>\nFig. 6. Sampling and measurement of chemical parameters of surface waters at profile V7-CH1<\/h6>\n
RESULTS<\/h2>\n
Tab.\u00a01. Average values of\u00a0the\u00a0monitored chemical parameters; the\u00a0worst results in\u00a0terms of\u00a0water quality are highlighted in\u00a0bold<\/h5>\n
<\/a>\nTab.\u00a02. Median values of\u00a0the\u00a0monitored chemical parameters; the\u00a0worst results in\u00a0terms of\u00a0water quality are highlighted in\u00a0bold<\/h5>\n
<\/a>\n<\/a>Fig. 7. Results of\u00a0automatic sampling during the\u00a0significant rainfall-runoff event from\u00a013\u201315 September 2024 at profile V4<\/h6>\n<\/h6>\n
<\/a><\/h6>\nFig. 8. Results of\u00a0automatic sampling during the\u00a0significant rainfall-runoff event from 13\u201315 September 2024 at profile V5<\/h6>\n
Tab.\u00a03. Calculated amount of\u00a0exported HS during the\u00a0significant rainfall-runoff event from 13\u201315 September 2024 at profile V5<\/h5>\n
<\/a>\nEffect of\u00a0the\u00a0reservoir on stream water chemistry<\/h3>\n
<\/a><\/h6>\nFig. 9. Box plots of\u00a0percentage change in\u00a0substance concentrations between profiles CH9 upstream of\u00a0the\u00a0reservoir and CH10 downstream of\u00a0the\u00a0reservoir; the\u00a0main\u00a0part is the\u00a0\u201cbox\u201d between the\u00a0first and third quartiles, inside which is a\u00a0line indicating the\u00a0median; the\u00a0box has \u201cwhiskers\u201d that show the\u00a0range of\u00a0data outside the\u00a0quartiles (typically\u00a0up\u00a0to\u00a01.5 times the\u00a0interquartile range); outliers are shown as separate points outside the\u00a0whiskers<\/h6>\n
<\/a>\nFig. 10. Water channel with an automatic sampler at profile V5<\/h6>\n
DISCUSSION<\/h2>\n
CONCLUSION<\/h2>\n
<\/a>\nAcknowledgements<\/h3>\n