drought

Groundwater abstraction noticeably reduces the flow of some watercourses during the dry season

The paper highlights the fact that some significant watercourses dry up during periods of minimal flows due to groundwater abstraction. It provides a summary of the most affected significant watercourses in the Czech Republic. Large concentrated groundwater abstraction has a considerable impact on small and medium-sized watercourses. To select the most significant effects of abstraction on stream flows, we used the ratio of abstraction to 355-day flows from 1931–1960. Watercourses exceeding 30 % were selected. In half of the selected cases the following relationship was confirmed: the 355-day flow from 1931–1960, reduced by the abstraction rate, is approximately equal to the 355-day flow from 1991–2020. The cases where this relation-ship does not apply can be explained by changes in abstraction volumes, declining groundwater levels and flows in the wider area due to groundwater collection and the use of static groundwater reserves. The effect of climate change is unlikely to be present in the baseflow in the cases studied. Our analysis identified 13 cases where groundwater abstraction is severely affecting the flow of significant watercourses. In about half of these cases, there is an alternative source of water that should be used when the flow of the watercourse is at a minimum. Another option to protect water resources is to apply the minimum groundwater level or minimum residual flow under the Water Act.

Methodology for creating a Map of the Vulnerability of the Quantity of Natural Groundwater Resources to Drought for the Czech Republic

Groundwater drought affecting groundwater availability is still mostly understood as a subset of hydrological drought. The impact of hydrological drought on groundwater is manifested with a delay and depends on its duration. An expert interactive Map of the Vulnerability of the Quantity of Dynamic Groundwater Resources to Drought for the Czech Republic was created as part of the TA CR project SS01010208 – “Controlled Groundwater Recharge as a Tool to Reduce the Impacts of Drought in the Czech Republic”. The presented vulnerability map is created on the basis of the use of precipitation normal and regression relationships between precipitation and total runoff and groundwater discharge (base flow) using the Base Flow Index (BFI) and ratio of base flow in the driest year of 2010–2019 to the long-term average of base flow (M index), which guarantees uniform processing for the entire Czech Republic at a scale of 1 : 50,000 and an objective comparison of the vulnerability of dynamic groundwater resources to drought throughout the country. It is also based on recorded groundwater abstraction and in the case of municipalities with individual supply, the abstraction is calculated from the number of inhabitants and the national average consumption of drinking water per capita. The Map is compiled based on the balance of dynamic groundwater resources and groundwater abstraction. It contains six categories and shows which regions and areas will struggle to have sufficient groundwater resources during periods of prolonged drought. It synthesizes all available flow logs and other data until 2020 and is designed so that the layers with variable information can be updated in the future.

Drought warning system and local threshold limits

Droughts and floods are extreme hydrological phenomena that are currently increasing in frequency due to the growing impact of climate change, and can have significant effects on our lives. Within the “PERUN” research project, an assessment of drought conditions and their development in the Czech Republic is being developed, along with the innovation of the warning system by the Czech Hydrometeorological Institute (CHMI). Drought is a natural phenomenon characterized by a gradual onset, long duration, and low dynamics, which requires a specific approach. The amendment to the Water Act introduces the obligation of regular reporting on drought and the establishment of a predictive service to be conducted by CHMI. Tools are being developed for long-term prediction of water resource conditions and a methodology for drought and water scarcity management plans. These plans aim to ensure water supply, protect the environment, and minimize the economic impacts. The decision-making body for issuing measures based on the drought plans is the Drought Commission, which operates at the regional level. The warning information is available on the HAMR web portal, which also displays local threshold limits for individual water resources.

„Water Centre“

The research project of the Technology Agency of the Czech Republic SS02030027 „Water systems and water management in the Czech Republic in conditions of climate change“, whose guarantor is the Ministry of the Environment, tries to answer the question of whether we will continue to have enough quality water. Climate change and the associated drought, as well as human behaviour and demands threaten water, and solutions must be sought for the immediate future.

Hydrological balance in selected watersheds of the Czech Republic with focus on drought period 2015–2019

The contribution is aimed to the determination and assessment of a hydrological balance at selected watersheds in Czech Republic during the dry period 2015–2019. Hydrological balance was processed in gauging stations of watershed Blatný stream, Lomnice, Skalice, Žehrovka, Javorka, Cidlina, Botič and upper Sázava river using data from Czech hydrometeorological institute. Monthly, long-term monthly and annual values were calculated for precipitation, runoff and evapotranspiration. Results were compared across the selected watersheds and with long-term period 1981–2010. Runoffs from watersheds were compared with gauging average discharge of an entire observation period.

Adaptation of towns and municipalities to floods and drought

This article is available in Czech only. For translation or more information on this topic, please contact author.   Souhrn Realizace komplexních adaptačních opatření je v posledních letech významným trendem ve všech velkých městech a obcích Evropy. Potřeba přizpůsobení se změně klimatu, vyznačující se střídáním krátkých a intenzivních povodňových epizod [1] a dlouhých období sucha,… Read more »

HAMR: Online drought management system – operational management during a dry episode

Increasing occurrence of drought periods in the Czech Republic has highlighted a necessity of legislation modification. At the same time, a need has emerged for tools supporting decision making and water resources management at various levels during the drought periods.

Catalogue of green water retention measures in the landscape and its application in the web map application

A catalogue of green water retention measures in landscape represents one of the results of long term project financed by the Ministry of Environment. The main goal of the catalogue was to summarize a set of measures with positive effects on water retention of landscape, with low impact on ecological status of water bodies.

Hydrological balance and available water resource in the czech republic during hydrological drought

The article deals with the assessment of the hydrological balance in a monthly time step in the territory of the Czech Republic, which was divided into 133 sub-basins for the period 1981–2015.

Policy of Protection from impacts of drought and water scarcity in the Czech Republic – consultation and processing

In the context of a severe drought period, which has started in 2014, an inter-ministerial commission WATER-DROUGHT was established to prepare a strategic policy document on protection from impacts of drought and water scarcity in the Czech Republic.

Evaluation of the impacts of drought on aquatic and water-bound organisms in surface water bodies

Within the framework of the sub-task “Evaluation of the impacts of drought on aquatic and water-bound organisms in surface water bodies“ a project involving activities to support the state administration in the drought issue in 2016 was prepared mainly a review of the potential impacts of drought on individual elements and indicators of water status assessment.

Risk assessment of drying up of small streams in the Czech Republic

A categorization of the Czech Republic territory in terms of the risk of drying up of small streams (1st to 4th order by Strahler) was proposed. Three levels of risk (low, medium and high) for basic hydrological units (catchment) were set. The risk levels were defined using selected abiotic characteristics of the hydrological units and their combinations.

Drought management and water reservoirs construction in the context of spatial planning

In the Czech Republic long-term protection of localities suitable for surface water storage (LASW) is done. Currently the number of them is 65; in the near future this list will be updated. The protection of these areas, however, has impacts on social and economic development of communities, local people and on the landscape itself, too.