{"id":34657,"date":"2025-02-11T18:59:45","date_gmt":"2025-02-11T17:59:45","guid":{"rendered":"https:\/\/www.vtei.cz\/2025\/02\/privalova-povoden-v-oblasti-chko-brdy-v-cervnu-2024-2\/"},"modified":"2025-02-12T21:35:14","modified_gmt":"2025-02-12T20:35:14","slug":"flash-flood-in-brdy-pla-in-june-2024","status":"publish","type":"post","link":"https:\/\/www.vtei.cz\/en\/2025\/02\/flash-flood-in-brdy-pla-in-june-2024\/","title":{"rendered":"Flash flood in Brdy PLA in June 2024"},"content":{"rendered":"

ABSTRACT<\/h2>\n

The article documents the course of the flash flood at the beginning of June 2024 in Brdy PLA, in the P\u0159\u00edbram Region, including reflection on its causes and possibilities for limiting the consequences of this type of flood in the future. Publicly available information was evaluated from the hydrometeorological situation in the Archive of weekly reports on the CHMI website for the nearest station to the flood-affected area, namely Neum\u011btely station. In that week, the highest weekly precipitation total for the Czech Republic was recorded at Neum\u011btely station. When evaluating landscape development based on archival maps or orthophoto maps, changes with some negative effects on water retention in the landscape were observed. It was mainly the gradual expansion of urban development into the original mosaic of dry or wet meadows and small fields, straightening and piping of watercourses, ploughing their floodplains, land reclamation of spring areas, and their subsequent replacement with arable land.<\/p>\n

INTRODUCTION<\/h2>\n

The\u00a0Brdy Highlands are over 70 km in\u00a0length and cover an area of\u00a0827\u00a0km2. The\u00a0highest point is Tok hill (865\u00a0m above sea level), which is part of\u00a0the\u00a0central Brdy hills. This is the\u00a0highest part of\u00a0the\u00a0Brdy, which was part of\u00a0a\u00a0military district and is now the\u00a0centre of\u00a0a\u00a0PLA [1\u20133]. The\u00a0Brdy hills are characterized by poor subsoil, which does not allow the\u00a0formation of\u00a0more fertile soils. These are concentrated only in\u00a0the\u00a0valleys of\u00a0watercourses. This is why, during medieval colonization of\u00a0the\u00a0Brdy region, settlements appeared only in\u00a0these lower-lying locations, and the\u00a0rest of\u00a0the\u00a0range remained forested [4]. Although the\u00a0landscape in\u00a0Brdy PLA seems unaltered at first glance, it has undergone many changes over the\u00a0last two centuries. These were not only the\u00a0changes in\u00a0the\u00a0species composition of\u00a0the\u00a0extensive Brdy forests, but especially the\u00a0non-forest areas around settlements, whether existing or disappeared. The\u00a0Brdy landscape was also significantly influenced in\u00a0the\u00a020th century due to military activities [5].<\/p>\n

Extreme hydrological phenomena are recorded in\u00a0the\u00a0oldest historical sources. From the\u00a0perspective of\u00a0dealing with the\u00a0consequences of\u00a0floods and droughts, various technical and organizational measures have been proposed which are intended to protect mainly built-up areas from floods or, conversely, retain\u00a0water in\u00a0the\u00a0landscape for periods of\u00a0drought. In\u00a0the\u00a0past, people had to rely on their observations and the\u00a0experience of\u00a0their ancestors, who knew where the\u00a0water caused damage during floods. If they did not do so, they would lose crops, livestock, property, or even their lives. If necessary, they built small water management structures in\u00a0forests, fields, in\u00a0and along streams. They knew where not to build their homes and what to do when a\u00a0flood or drought came. It was the\u00a0so-called \u201cflood memory\u201d, which they could rely on. Currently, awareness of\u00a0flood memory is declining, and long-term experience is often no longer shared and respected, whether it is due to people becoming more detached from nature, focusing on other life priorities, or perhaps because of\u00a0expectations of\u00a0government help in\u00a0times of\u00a0emergency.<\/p>\n

The\u00a0following text documents the\u00a0course of\u00a0a\u00a0flash flood in\u00a0Brdy Protected Landscape Area in\u00a0the\u00a0P\u0159\u00edbram region, specifically in\u00a0the\u00a0cadastral areas Drahl\u00edn and S\u00e1dek, on 2 June 2024. Several such flash floods normally occur in\u00a0the\u00a0Czech Republic during a\u00a0year; some years there are more, others fewer. As a\u00a0rule, they do not occur in\u00a0the\u00a0same locations, but given ongoing climate change, previous experience cannot be completely relied on. There are certainly locations that are more susceptible for various reasons. These types of\u00a0floods are usually not as publicized and will not cause such overall damage as the\u00a0catastrophic regional floods affecting a\u00a0large part of\u00a0the\u00a0Czech Republic, which occurred in\u00a0July 1997, August 2002, June 2013 or most recently in\u00a0September 2024, or as in\u00a0Spain\u00a0at the\u00a0end of\u00a0October 2024 in\u00a0the\u00a0Valencia area, or at the\u00a0beginning of\u00a0November 2024 in\u00a0the\u00a0Barcelona area.<\/p>\n

LOCATION DESCRIPTION<\/h2>\n

The\u00a0flood described here is documented in\u00a0the\u00a0area of\u00a0the\u00a0cadastral area Drahl\u00edn and the\u00a0neighbouring, lower-lying cadastral area S\u00e1dek, which are located in\u00a0the\u00a0municipalities of\u00a0Drahl\u00edn and S\u00e1dek in\u00a0P\u0159\u00edbram district in\u00a0the\u00a0Central Bohemian Region. This cadastral unit directly borders Brdy PLA, where the\u00a0cadastral areas Drahl\u00edn in\u00a0Brdy and S\u00e1dek in\u00a0Brdy are located on the\u00a0site of\u00a0the\u00a0former Brdy Military District. From a\u00a0hydrological point of\u00a0view, this area is located in\u00a0the\u00a0Berounka sub-basin, in\u00a0the\u00a0second order basin\u00a01-11\u00a0Berounka from \u00daslava to the\u00a0estuary in\u00a0the\u00a0third order basin\u00a01-11-04 Litavka and Berounka from Litavka to Lod\u011bnice, and in\u00a0the\u00a0fourth order basin\u00a01-11-04-0100 Drahl\u00ednsk\u00fd stream. Drahl\u00ednsk\u00fd stream itself is 4.81 km long and its catchment area covers\u00a07.85\u00a0km2 [6] (Figs. 1<\/em> and 2<\/em>).<\/p>\n

\"\"<\/a><\/h6>\n
Fig.\u00a01. The\u00a0researched area in\u00a0a\u00a0hydrological context<\/h6>\n
\"\"<\/a><\/h6>\n
Fig. 2. The\u00a0researched area on current ZTM\u00a050<\/h6>\n

The\u00a0geological subsoil consists of\u00a0gravels, sands, conglomerates, and sandstones [7]. According to the\u00a0MKSP classification, the\u00a0predominant soil types are pseudogley cambisol and primary pseudogley. In\u00a0the\u00a0floodplain\u00a0of\u00a0the\u00a0Drahl\u00ednsk\u00fd stream and its nameless left-hand tributary, typical gley predominates, while in\u00a0forest stands, it is dystric cambisol and ranker [8]. Based on the\u00a0geomorphological division, the\u00a0area is located on the\u00a0border of\u00a0the\u00a0T\u0159ebsk\u00e1 pahorkatina and T\u0159emo\u0161ensk\u00e1 vrchovina districts, which are part of\u00a0the\u00a0Brdy Highlands geomorphological unit, located in\u00a0Brdy region [1, 2, 9]. Drahl\u00edn cadastral area contains Drahl\u00ednsk\u00e9 louky Nature Monument, which is also a\u00a0European Site of\u00a0Importance (ESI) in\u00a0the\u00a0Natura 2000 system. It was declared as an ESI covering\u00a012.6\u00a0ha on 3\u00a0November 2009 and as a\u00a0Nature Monument covering\u00a013\u00a0ha on 22 July 2016. It consists of\u00a0two separate meadows on the\u00a0eastern and western edges of\u00a0the\u00a0built-up area near both ponds in\u00a0Drahl\u00edn cadastral area. On\u00a019\u00a0April\u00a02024, Licitanta Nature Monument was declared in\u00a0the\u00a0same cadastral register covering\u00a02.7\u00a0ha, which also belongs within\u00a0Brdy PLA [10].<\/p>\n

Brdy PLA and the\u00a0former Brdy Military District<\/h3>\n

The\u00a0history of\u00a0the\u00a0Brdy Military District began in\u00a0the\u00a01920s, when the\u00a0then Ministry of\u00a0Defence of\u00a0Czechoslovakia established a\u00a0new artillery range to increase the\u00a0amount of\u00a0artillery and modernize weapons. Brdy was chosen as the\u00a0new area for the\u00a0training ground as its terrain\u00a0resembled border areas and seemed to be an\u00a0ideal location for military purposes. However, this did not please the\u00a0civilian population, which led to a\u00a0strong wave of\u00a0resistance [2, 11]. The\u00a0creation of\u00a0the\u00a0shooting range was protested against not only by residents, who were threatened with eviction, but also by a\u00a0number of\u00a0prominent national figures \u2013 scientists, writers, poets, and others. A\u00a0group of\u00a0parliament members also rebelled, submitting a\u00a0proposal in\u00a01920 to establish a\u00a0national park in\u00a0the\u00a0Brdy hills, which would prevent the\u00a0area from being occupied by the\u00a0army. However, the\u00a0protests (the\u00a0strongest in\u00a01924 and 1925) were in\u00a0vain\u00a0and, on 19 February 1926, the\u00a0government approved the\u00a0project. The\u00a0construction of\u00a0the\u00a0shooting range began on 14 July 1927 and was completed in\u00a0the\u00a0same year [2, 12]. The\u00a0following year, the\u00a0headquarters of\u00a0the\u00a0military artillery training ground and the\u00a0headquarters of\u00a0military forestry enterprises were established. In\u00a01929, barracks and residential buildings for military employees were built and a\u00a0section of\u00a0forest was cut down to build new target impact areas [2, 11]. However, the\u00a0army did not prohibit anyone from entering the\u00a0area at that time; the\u00a0place was busy with tourists. A\u00a0ban was limited to the\u00a0target impact areas only. The\u00a0German army, which began using Brdy shooting range during the\u00a0occupation, expanded it westward and evicted the\u00a0original inhabitants. However, because the\u00a0German army left all the\u00a0buildings in\u00a0the\u00a0area, the\u00a0inhabitants were able to return after the\u00a0war. In\u00a0the\u00a0early 1950s, the\u00a0entry ban was reinstated and, in\u00a01952, the\u00a0area began to expand again. Most of\u00a0the\u00a0buildings were razed to the\u00a0ground and only a\u00a0few gamekeepers\u2019 lodges remained [2, 12]. Other buildings included the\u00a0T\u0159i Trubky hunting lodge and the\u00a0ruins of\u00a0Valdek Castle. In\u00a0the\u00a01990s, there were further attempts to abolish the\u00a0military district or reduce the\u00a0military area, to declare Brdy a\u00a0protected area and to open it to tourists. However, the\u00a0Ministry of\u00a0the\u00a0Environment rejected these proposals, as the\u00a0military area was protected from the\u00a0influences of\u00a0civilization [13]. After long negotiations, based on Act No. 15\/2015 Coll., on the\u00a0abolishment of\u00a0the\u00a0Brdy military district, on the\u00a0determination of\u00a0the\u00a0borders of\u00a0military districts, on the\u00a0change of\u00a0regional borders and on the\u00a0amendment of\u00a0related laws (the\u00a0Act on the\u00a0Borders of\u00a0Military Districts), Brdy military district was finally abolished on 1 January 2016 and changed to PLA. After its abolishment, it was divided into 27 cadastral areas of\u00a0which 11 cadastral areas fell under P\u0159\u00edbram district, six under Beroun district, seven under Rokycany district, and three under Plze\u0148-south district [14].<\/p>\n

METHODOLOGY<\/h2>\n

The\u00a0first step was to select areas suitable for observing and documenting the\u00a0onset of\u00a0flash floods so that they would be relatively quickly accessible from Prague. The\u00a0presented locations of\u00a0Drahl\u00edn and S\u00e1dek, on the\u00a0borders of\u00a0Brdy PLA, meet these conditions. The\u00a0next step was a\u00a0field survey of\u00a0these locations to verify their current condition, both during the\u00a0ongoing flood and under standard conditions. After that, publicly available hydrometeorological situation information in\u00a0the\u00a0weekly reports archive on the\u00a0CHMI website were evaluated [15].<\/p>\n

Subsequently, a\u00a0comparison of\u00a0the\u00a0current and historical state of\u00a0the\u00a0study area was carried out based on the\u00a0interpretation of\u00a0map data. To display the\u00a0historical state of\u00a0the\u00a0landscape within\u00a0various types of\u00a0comparison, the\u00a0following maps were used: Maps of\u00a0the\u00a0Stable Cadastre, the\u00a0Map of\u00a0the\u00a02nd Military Mapping, the\u00a0Historical Orthophotomap from the\u00a01950s, and archival orthophotomaps. To display the\u00a0current state, the\u00a0current Basic Topographic Map of\u00a0the\u00a0Czech Republic 1 : 10,000 (ZTM 10) and 1 : 50,000 (ZTM 50) and the\u00a0current Orthophotomap of\u00a0the\u00a0Czech Republic were used.<\/p>\n

Current map data used<\/h3>\n

Current ZTM 10, ZTM 50 and Orthophotomap of\u00a0the\u00a0Czech Republic<\/strong><\/span><\/p>\n

These maps are available via WMS or WMTS from the \u010c\u00daZK Geoportal [16], where they are continuously updated as needed. The displayed state on ZTM 10 and ZTM 50 may differ according to individual segments, which are updated separately (e.g. road network), and therefore may not display the actual state of the landscape in all respects in a given period. Currently, both maps should correspond to the state of the landscape in 2020\u20132023. The entire Orthophotomap of the Czech Republic is updated in a two-year cycle. Approximately one half\u00a0of\u00a0the\u00a0Czech Republic is updated annually, and since 2020, regional borders have been taken into account in\u00a0the\u00a0update.<\/p>\n

Archival map data used<\/h3>\n

Stable Cadastre<\/span><\/strong><\/p>\n

The oldest usable map material with a detailed depiction of landscape cover is maps of the Stable Cadastre, or more precisely, Imperial Imprints of the Stable Cadastre. They record the historical state of the landscape from the mid-19th century. They were produced at a scale of 1 : 2,880, or 1 : 5,760 in mountainous areas. The original maps were drawn in the field and capture the actual state of the landscape before the industrial revolution, i.e. in 1824\u20131836 (Moravia and Silesia) and 1826\u20131843 (Bohemia). Their disadvantage when used for landscape change analyses in\u00a0a\u00a0GIS environment is the\u00a0need to georeference individual map sheets. Viewing and ordering is possible on the\u00a0website of\u00a0the\u00a0Archive Maps of\u00a0the\u00a0Central Archives of\u00a0Surveying and Cadastre [17].<\/p>\n

Map of\u00a0the\u00a02nd Military Mapping<\/strong><\/span><\/p>\n

This is the first relatively precise topographic map. It was drawn on a scale of 1 : 28,800 in 1836\u20131852. Its creation was preceded by military triangulation, which was the geodetic basis of this work. The material used were the Maps of the Stable Cadastre. The map of the 2nd Military Mapping was created at the time of the onset of the Industrial Revolution and the development of intensive forms of agriculture, when the area of arable land increased by half in 100 years and the area of forest reached a historical minimum. The first railway lines are also recorded here [18]. It is available for viewing on the National Geoportal INSPIRE [19] and also as WMTS [20]. Individual map sheets can be searched within the oldmaps.geolab.cz application of the Geoinformatics Laboratory of the Faculty of Environmental Sciences of J. E. Purkyn\u011b University in \u00dast\u00ed nad Labem [18].<\/p>\n

Historical orthophotomap from the\u00a01950s<\/strong><\/span><\/p>\n

The historical orthophoto map includes layers of aerial photographs mainly from 1952\u20131954, supplemented by images from 1937\u20131970 and 1996 where relevant photographic data do not exist for the given period. The Orthophotomap of the Czech Republic from historical images of the first nationwide aerial photography from the 1950s was created as part of the National Inventory of Contaminated Sites (NIKM) project. Aerial survey images were provided by the Military Geographical and Hydrometeorological Office (VGHM\u00da\u0159) Dobru\u0161ka and processed by GEODIS BRNO, s. r. o. It is available for viewing on the\u00a0National Geoportal INSPIRE [19] and also as WMTS [20].<\/strong><\/span><\/p>\n

Archival orthophotomaps<\/strong><\/span><\/p>\n

These orthophotomaps are available as WMS from the\u00a0\u010c\u00daZK Geoportal. Only the\u00a0part of\u00a0the\u00a0area that was photographed within\u00a0one year is always displayed, according to the\u00a0stages of\u00a0photography in\u00a0the\u00a0Czech Republic in\u00a01998\u20132021.
\nIn\u00a0the\u00a0layers from 1998 to 2001, the\u00a0data is displayed in\u00a0black and white, the\u00a0layers from 2003 contain\u00a0colour images [16].<\/p>\n

FLASH FLOOD ON 2 JUNE 2024 IN THE DRAHL\u00cdN AND S\u00c1DEK MUNICIPALITIES<\/h2>\n

On 2 June 2024, there were thunderstorms and torrential rain\u00a0in\u00a0the\u00a0Brdy region. This precipitation wase very intense and the\u00a0Litavka inundated in\u00a0P\u0159\u00edbram, Bratkovice, and further downstream. The\u00a0Litavka is the\u00a0main\u00a0river in\u00a0the\u00a0area, so its inundation was quite expected in\u00a0this meteorological situation. However, the\u00a0onset of\u00a0the\u00a0flood was also very rapid in\u00a0the\u00a0Drahl\u00ednsk\u00fd stream basin. Torrential rainfall in\u00a0the\u00a0villages of\u00a0Drahl\u00edn and S\u00e1dek and their surroundings caused the\u00a0basements of\u00a0several houses in\u00a0these villages to flood. Water poured from the\u00a0forest, which is part of\u00a0Brdy PLA, and also caused temporary impassability of\u00a0some sections of\u00a0roads, which complicated the\u00a0work of\u00a0firefighters in\u00a0pumping water out of\u00a0flooded basements\u00a0[21]. The\u00a0consequences of\u00a0this flood were documented in\u00a0the\u00a0area of\u00a0the\u00a0piping and canalization of\u00a0a\u00a0small stream below the\u00a0main\u00a0road in\u00a0the\u00a0village of\u00a0Drahl\u00edn, where the\u00a0stream inundated. The\u00a0sewerage system was not able to absorb such a\u00a0large amount of\u00a0water, causing it to overflow across the\u00a0main\u00a0road and subsequently flood the\u00a0basements of\u00a0several properties in\u00a0the\u00a0area. The\u00a0situation as of\u00a02\u00a0June\u00a02024 compared to standard situation is shown in\u00a0Figs. 3 to 6. In\u00a0built-up areas, a\u00a0very common issue in\u00a0recent years has been undercapacity of\u00a0riverbeds, undercapacity of\u00a0bridges and culverts, clogged culverts that are not sufficiently managed, and undercapacity of\u00a0watercourse piping (often all together). The\u00a0above-mentioned situation only confirms this issue.<\/p>\n\"\"<\/a>\n

Fig. 3. Situation in the area of piping and canalization of a small stream below the main road in the village of Drahl\u00edn during the flash flood in June 2024 compared to standard situation at the end of August of the same year<\/h6>\n\"\"<\/a>\n
Fig. 4. Situation in Drahl\u00edn on the main road towards Obecnice in the area of piping and\u00a0canalization of a small stream during the flash flood in June 2024<\/span><\/h6>\n\"\"<\/a>\n
Fig. 5. Situation in Drahl\u00edn below the main road in locality no. 121 and 122 during the\u00a0flash flood in June 2024 compared to standard situation at the end of August of\u00a0the\u00a0same year<\/h6>\n\"\"<\/a>\n
Fig. 6. Minor watercourse near the main road, standard situation (October 2024)<\/h6>\n

The\u00a0pond in\u00a0the\u00a0eastern part of\u00a0the\u00a0village could not hold such a\u00a0large amount of\u00a0precipitation either. Drahl\u00ednsk\u00fd stream below this pond inundated and the\u00a0adjacent local road was flooded (Fig. 7) [21]. The\u00a0above-mentioned documented sites in\u00a0the\u00a0Drahl\u00edn cadastral area in\u00a0the\u00a0context of\u00a0landscape development are shown in\u00a0Fig. 8<\/em>.<\/p>\n\"\"<\/a>\n

Fig. 7. Flooding of local roads in Drahl\u00edn in June 2024 (Drahl\u00ednsk\u00fd zpravodaj<\/span> [21]) compared to standard situation in November of the same year<\/h6>\n

 <\/p>\n\"\"<\/a> \"\"<\/a>\"\"<\/a>\"\"<\/a>\"\"<\/a>\"\"<\/a>\n

Fig. 8. Documented localities in\u00a0Drahl\u00edn cadastral area in\u00a0the\u00a0context of\u00a0landscape development on the\u00a0Stable cadastre, Historical Orthophotomap from the\u00a01950s, Archival\u00a0Orthophotomaps from 2001, 2005 and 2015 and current Orthophotomap of\u00a0the\u00a0Czech Republic<\/h6>\n

Drahl\u00ednsk\u00fd stream in\u00a0the\u00a0S\u00e1dek cadastral area also caused temporary traffic inaccessibility of\u00a0the\u00a0municipalities of\u00a0S\u00e1dek and Drahl\u00edn towards Lhota u\u00a0P\u0159\u00edbram\u011b and P\u0159\u00edbram, as water overflowed the\u00a0road bridge. The\u00a0situation on 2 June 2024, after the\u00a0peak had subsided, compared to the\u00a0usual state, is shown in\u00a0Figs. 9<\/em> and 10<\/em>. The\u00a0location in\u00a0the\u00a0context of\u00a0landscape development is shown in\u00a0Fig. 11<\/em>.<\/p>\n\"\"<\/a>\n

Fig. 9. Situation near the road bridge over Drahl\u00ednsk\u00fd stream during the flash flood in\u00a0June\u00a02024, compared to standard situation at the end of August of the same year<\/span><\/h6>\n\"\"<\/a>\n
Fig. 10. Situation behind the road bridge over Drahl\u00ednsk\u00fd stream during the flash flood in\u00a0June 2024, compared to standard situation at the end of August of the same year<\/span><\/h6>\n\"\"<\/a>\"\"<\/a>\"\"<\/a>\"\"<\/a>\"\"<\/a>\"\"<\/a>\n
Fig. 11. Documented localities in\u00a0S\u00e1dek cadastral area in\u00a0the\u00a0context of\u00a0landscape development on the\u00a0Stable cadastre, Historical Orthophotomap from the\u00a01950s, Archival\u00a0Orthophotomaps from 2001, 2005 and 2015 and current Orthophotomap of\u00a0the\u00a0Czech Republic<\/h6>\n

The\u00a0forest stands were not able to contain\u00a0these torrential rainfalls. Therefore, a\u00a0field survey was carried out in\u00a0this area as well. Since these forests were part of\u00a0Brdy Military District until the\u00a0end of\u00a02015, there is a\u00a0relatively dense network of\u00a0paved roads and intensive forest management was also carried out here. A\u00a0comparison of\u00a0the\u00a0area and condition of\u00a0forest stands in\u00a0the\u00a0study area and its surroundings is shown on maps and orthophotomaps in\u00a0Figs. 12<\/em> and 13<\/em>, respectively. The\u00a0current state of\u00a0the\u00a0forest, marked by the\u00a0effects of\u00a0erosion, is shown in\u00a0Fig. 14<\/em>.<\/p>\n\"\"<\/a>\n

Fig. 12. Comparison of\u00a0the\u00a0forest stands state, including the\u00a0surrounding landscape, shown on Map of\u00a0the\u00a02nd military mapping and on current ZTM\u00a010<\/h6>\n\"\"<\/a>\"\"<\/a>\"\"<\/a>\"\"<\/a>\"\"<\/a>\"\"<\/a>\n
Fig. 13. Comparison of\u00a0the\u00a0forest stands state, including the\u00a0surrounding landscape, shown on Historical Orthophotomap from the\u00a01950s, Archival Orthophotomaps from 2001, 2005, 2015 and 2019 and current Orthophotomap of\u00a0the\u00a0Czech Republic<\/h6>\n\"\"<\/a>\n
Fig. 14. The\u00a0current state of\u00a0the\u00a0forest marked by the\u00a0effects of\u00a0erosion in Brdy PLA (October 2024)<\/h6>\n

Subsequently, publicly available hydrometeorological situation information in the weekly report archive on the CHMI website [15] were evaluated. Not all stations with recorded gauging are listed here, only selected ones. The closest such station to the study area is in Neum\u011btely. In the Report No.: 22\/Week: 27 May to 2 June 2024, this station reports a weekly precipitation total of 84 mm, which is 400 % of the normal with six rainy days per week. This is the highest weekly precipitation total of all the stations listed here and the second highest percentage of the normal after Doksany station (440 %). In the previous week (Report No.: 21\/Week: 20 May to 26 May 2024), this station reported a\u00a0weekly precipitation total of\u00a014\u00a0mm, which is 83\u00a0% of\u00a0the\u00a0normal with five rainy days per week. In\u00a0the\u00a0following week (Report No.: 23\/Week: 3 June to 9 June 2024), this station reported a\u00a0weekly precipitation total of\u00a04\u00a0mm, which is 24\u00a0% of\u00a0the\u00a0normal with one rainy day per week. Although weekly precipitation statistics can be misleading, as they do not consider the\u00a0distribution or intensity of\u00a0precipitation (or other quantities) on individual days, and Neum\u011btely station is not in\u00a0the\u00a0immediate vicinity of\u00a0the\u00a0study area, these data can confirm the\u00a0enormous amount of\u00a0precipitation in\u00a0Brdy PLA in\u00a0the\u00a0P\u0159\u00edbram region, including Drahl\u00edn and S\u00e1dek municipalities.<\/p>\n

DISCUSSION<\/h2>\n

Given the\u00a0location of\u00a0this June flash flood in\u00a0the\u00a0headwaters of\u00a0Drahl\u00ednsk\u00fd stream in\u00a0the\u00a0immediate vicinity of\u00a0Brdy PLA, it can be clearly concluded that this landscape cannot accommodate such an amount of\u00a0torrential rainfall, especially after previous rainfall. At first glance, this is a\u00a0landscape that has been relatively little altered by human activity. However, a\u00a0comparison of\u00a0maps (Figs. 8, 11<\/em>, and 13<\/em>) shows that significant changes have occurred in\u00a0this location, with a\u00a0negative impact on the\u00a0retention and purity of\u00a0water in\u00a0the\u00a0landscape. This mainly involved the\u00a0gradual expansion of\u00a0a\u00a0built-up area into the\u00a0original mosaic of\u00a0dry and wet meadows and small fields, as well as the\u00a0reduction of\u00a0the\u00a0historical road network, the\u00a0straightening and piping of\u00a0watercourses and the\u00a0ploughing of\u00a0their floodplains. The\u00a0land reclamation of\u00a0spring areas and their replacement with arable land also had an impact; in\u00a0some locations, after the\u00a0destruction of\u00a0land reclamation structures, the\u00a0original landscape cover was partially restored with the\u00a0help of\u00a0succession (Fig. 11<\/em>).<\/p>\n

Fig. 12<\/em> indicates that the\u00a0area of\u00a0forest stands has slightly expanded in\u00a0the\u00a0study area; however, the\u00a0orthophotomaps in\u00a0Fig. 13<\/em> clearly show that, due to intensive forest management, a\u00a0large number of\u00a0extensive clearings were created \u2013 this is most noticeable in\u00a0the\u00a0image from 2015. This was coincidentally the\u00a0last year when this area was under the\u00a0administration of\u00a0the\u00a0Military Forests and not under the\u00a0Nature Conservation Agency of\u00a0the\u00a0Czech Republic (NCA CR).<\/p>\n

A\u00a0comparison of\u00a0the\u00a0development of\u00a0the\u00a0location of\u00a0watercourses and water bodies in\u00a0the\u00a0area shows that both the\u00a0largest ponds in\u00a0Drahl\u00edn cadastral area were founded only after 1953. In\u00a0addition to the\u00a0straightening \u2013 and in\u00a0some sections even the\u00a0piping \u2013 of\u00a0the\u00a0Drahl\u00ednsk\u00fd stream and its tributaries, the\u00a0designation of\u00a0the\u00a0main\u00a0stream also changed. On the\u00a0current ZTM\u00a010 and ZTM 50, the\u00a0section that originates above Mal\u00fd Drahl\u00edn, in\u00a0the\u00a0eastern part of\u00a0the\u00a0municipality of\u00a0Drahl\u00edn, is designated as the\u00a0main\u00a0flow (Figs. 2 and 12). On the\u00a0Maps of\u00a0the\u00a0Stable Cadastre, the\u00a0current \u2013 \u200b\u200bpartially piped \u2013 left-sided tributary of\u00a0the\u00a0Drahl\u00ednsk\u00fd stream, which rises in\u00a0the\u00a0northern part of\u00a0the\u00a0area in\u00a0the\u00a0current Brdy PLA and flows along the\u00a0Drahl\u00edn village square, is drawn as the\u00a0main\u00a0stream. The\u00a0current spring section is not drawn here (however, a\u00a0group of\u00a0mostly wet but also dry meadows is shown, indicating a\u00a0possible small stream or spring area). On the\u00a0Maps of\u00a0the\u00a0Stable Cadastre, the\u00a0Drahl\u00ednsk\u00fd stream is listed under the\u00a0name \u201cPotuczek\u201d (Figs. 8<\/em> and 11<\/em>). At the\u00a0borders of\u00a0the\u00a0cadastral areas Drahl\u00edn and S\u00e1dek, the\u00a0usual watercourse outline only passes into a\u00a0small line and is then not drawn in\u00a0the\u00a0mosaic of\u00a0wet meadows at all (Fig. 11). The\u00a0Maps of\u00a0Stable Cadastre are reliable; however, they have shortcomings in\u00a0depicting small streams. In\u00a0some locations where it is obvious that a\u00a0small stream should be located (wet meadows are placed in\u00a0the\u00a0way that indicates a\u00a0stream or a\u00a0spring area), however, it is not there. Either it was a\u00a0blanket spring area where no main\u00a0stream existed, or some small streams were simply recorded only from a\u00a0certain\u00a0width [22, 23].<\/p>\n

A\u00a0comparison of\u00a0precipitation totals in\u00a0the\u00a0week from 27 May to 2 June\u00a02024 at Neum\u011btely station and at other published stations with the\u00a0week from 9\u00a0to 15\u00a0September 2024, when catastrophic floods occurred in\u00a0a\u00a0large area of\u00a0the\u00a0Czech Republic (especially in\u00a0the\u00a0Oder basin) clearly shows that from these data alone and without direct observation, the\u00a0actual intensity of\u00a0precipitation cannot be determined, and thus episodes leading to floods or flash floods cannot be indicated directly on individual days. Neum\u011btely station itself reports a\u00a0weekly precipitation total of\u00a093\u00a0mm, which is 870\u00a0% of\u00a0the\u00a0normal with six rainy days per week. Compared to the\u00a0week from 27 May to 2\u00a0June\u00a02024, there was an increase of\u00a09\u00a0mm, but in\u00a0May, 84\u00a0mm was \u201conly\u201d 400\u00a0% of\u00a0the\u00a0normal with the\u00a0same number of\u00a0rainy days. The\u00a0data from this week in\u00a0September clearly confirms the\u00a0extraordinary precipitation situation over almost the\u00a0entire area of\u00a0the\u00a0Czech Republic; however, there was no flash or \u201cstandard\u201d flood in\u00a0the\u00a0Drahl\u00ednsk\u00fd stream basin. The\u00a0saturation of\u00a0the\u00a0area also has a\u00a0significant impact on the\u00a0amount of\u00a0runoff in\u00a0the\u00a0basin. This is determined not only by precipitation, but also by the\u00a0temperatures and evaporation in\u00a0the\u00a0previous period. When the\u00a0affected area is significantly saturated, a\u00a0large amount of\u00a0water flows away during torrential rainfall not only from impervious surfaces, but also from other surfaces that would otherwise absorb at least a\u00a0significant part of\u00a0the\u00a0rainfall. Before the\u00a0flood in\u00a0September 2024, the\u00a0area was very slightly saturated and it rained for several days with less intensity than in\u00a0June\u00a02024. On the\u00a0CHMI website [24], daily precipitation totals can be found at all (historical and currently gauging) meteorological stations; however, for current gauging stations, it is only until 31 December 2023 at present. The\u00a0closest stations to the\u00a0study area are Podles\u00ed and P\u0159\u00edbram. When the\u00a0data are also available for 2024, it will be possible to describe in\u00a0more detail the\u00a0precipitation episode from the\u00a0beginning of\u00a0June in\u00a0the\u00a0municipalities of\u00a0Drahl\u00edn and S\u00e1dek and compare it with the\u00a0situation in\u00a0mid-September.<\/p>\n

So far, we have mentioned the\u00a0freely available archive data managed by the\u00a0CHMI on the\u00a0precipitation situation in\u00a0a\u00a0given area within\u00a0the\u00a0Czech Republic. However, if citizens would like to actively monitor the\u00a0risk of\u00a0impending flash floods, they can use the\u00a0Flash Flood Indicator operated by CHMI. It has been available to the\u00a0public for several years now; it provides information on both the\u00a0current area saturation and a\u00a0potential precipitation (in\u00a0one, three, and six hours) and calculates the\u00a0current risk of\u00a0flash flooding in\u00a0our country every 15\u00a0minutes [25]. This shows both the\u00a0risk of\u00a0local flooding in\u00a03 x 3 km grids and the\u00a0risk of\u00a0flash flooding on small streams. In\u00a0the\u00a0application, it is marked with a\u00a0coloured flag, including the\u00a0expected approximate time of\u00a0culmination. The\u00a0results of\u00a0the\u00a0calculation of\u00a0the\u00a0aggregate risk of\u00a0flash floods are presented in\u00a0a\u00a0polygon layer of\u00a0municipalities with extended powers (ORP), which are coloured according to the\u00a0currently achieved maximum risk level. The\u00a0calculated risk level always attributed to the\u00a0entire ORP territorial district, even if only a\u00a0smaller part of\u00a0it may be affected. However, the\u00a0Flash Flood Indicator application is operated only in\u00a0the\u00a0convective season (approximately April to October) and is available from the\u00a0Flood Reporting and Forecasting Service website\u00a0[26]. To monitor actual and expected precipitation, an application designed for detailed weather analysis and short-term precipitation forecasting (nowcasting) can also be used. This application displays, among other things, measured data (station gauging) and area-wide combined quantitative precipitation estimates (MERGE) [27]. Currently, a\u00a0modernized version of\u00a0MERGE2 is used, which allows updating the\u00a0precipitation calculation every 10\u00a0minutes [28]. These websites only provide current data; archived data are available at the\u00a0CHMI upon request.<\/p>\n

CONCLUSION<\/h2>\n

In\u00a0built-up areas, it would be desirable to pay more attention to issues with under-capacity piping and culverts and clogged or under-capacity channels of\u00a0small watercourses.<\/p>\n

It would also be appropriate to focus on landscape restoration in\u00a0Drahl\u00ednsk\u00fd stream basin\u00a0outside the\u00a0PLA, especially on the\u00a0restoration of\u00a0wetland habitats in\u00a0place of\u00a0those that have disappeared, as the\u00a0historical location of\u00a0such elements is a\u00a0very strong argument for their restoration (the\u00a0designation of\u00a0the\u00a0NM\/ESI Drahl\u00ednsk\u00e9 louky can serve as an example of\u00a0good practice). It is also necessary to restore the\u00a0beds of\u00a0small streams and restore their floodplains where possible. These landscape elements are also part of\u00a0the\u00a0solution to adapt to the\u00a0issues caused by ongoing climate change. Their restoration should primarily lead to higher water retention in\u00a0the\u00a0landscape and an increase in\u00a0landscape diversity.<\/p>\n

This is in\u00a0line with the\u00a0EU Biodiversity Strategy to 2030 [29], which is a\u00a0valid long-term plan for nature conservation, halting ecosystem degradation and restoring biodiversity in\u00a0Europe. The\u00a0Strategy recalls that biologically diverse ecosystems, such as wetlands as well as freshwater, forest, and agricultural ecosystems, when in\u00a0good condition, provide a\u00a0number of\u00a0essential ecosystem services, and the\u00a0benefits of\u00a0restoring damaged ecosystems to good condition far outweigh the\u00a0costs of\u00a0their restoration. The\u00a0EU Biodiversity Strategy for 2030 sets a\u00a0commitment to legally protect at least 30\u00a0% of\u00a0land and inland waters. The\u00a0text also calls for greater efforts to restore freshwater ecosystems and natural river functions, including restoring at least 25,000 km of\u00a0free-flowing rivers compared to 2020, when the\u00a0EU Biodiversity Strategy for 2030 was adopted.<\/p>\n

Hopefully, these will not be just declarations and the\u00a0measures mentioned will actually be implemented in\u00a0practice. In\u00a0some parts of\u00a0the\u00a0Czech Republic, truly comprehensive changes are needed. Maybe it is not too late…<\/p>\n

Acknowledgements<\/h3>\n

The\u00a0article was created within\u00a0the\u00a0framework of\u00a0the\u00a0internal grant of\u00a0the\u00a0TGM WRI No. 3600. 23\/2024 (Research support \u2013 institutional support, department 230).<\/em><\/p>\n

The\u00a0 Czech version of\u00a0 this article was peer-reviewed, the\u00a0 English version was\u00a0translated from the\u00a0Czech original by Environmental Translation Ltd.<\/p>\n","protected":false},"excerpt":{"rendered":"

The article documents the course of the flash flood at the beginning of June 2024 in Brdy PLA, in the P\u0159\u00edbram Region, including reflection on its causes and possibilities for limiting the consequences of this type of flood in the future. Publicly available information was evaluated from the hydrometeorological situation in the Archive of weekly reports on the CHMI website for the nearest station to the flood-affected area, namely Neum\u011btely station. In that week, the highest weekly precipitation total for the Czech Republic was recorded at Neum\u011btely station. When evaluating landscape development based on archival maps or orthophoto maps, changes with some negative effects on water retention in the landscape were observed. It was mainly the gradual expansion of urban development into the original mosaic of dry or wet meadows and small fields, straightening and piping of watercourses, ploughing their floodplains, land reclamation of spring areas, and their subsequent replacement with arable land.<\/p>\n","protected":false},"author":8,"featured_media":34568,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86,93],"tags":[1980,674,3732,1982,3733],"coauthors":[1421],"class_list":["post-34657","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","category-two-articles","tag-archival-maps","tag-floods","tag-forest-management","tag-water-retention-in-the-landscape","tag-watercourse-management"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/34657","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=34657"}],"version-history":[{"count":6,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/34657\/revisions"}],"predecessor-version":[{"id":34739,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/34657\/revisions\/34739"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/34568"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=34657"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=34657"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=34657"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=34657"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}