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The present material demonstrates appliance of regional studies on the area of Central Danube Plain in Bulgaria for determination the characteristic maximum flows at nonobserved river sections with focusing on for flood risk areas. River flow is characterized by annual variability in maximum runoff caused by climatic factors and anthropogenic impacts. For this reason, in most cases, information from hydrometric stations cannot be used directly. One of the main tasks of hydrological research is the transfer of info...

Water resource of a given river basin is the main component of the ecosystem and water resources management system as well. Ecological flows are considered within the context of the Water Framework Directive (WFD) as -a hydrological regime consistent with the achievement of the environmental objectives of the WFD in natural surface water bodies as mentioned in Article 4(1). The so-called Heavily Modified Water Bodies (HMWB) or -regulated rivers- have modified flow, which is influenced by reservoir compensation rel...

River hydrology is a key component in river resources planning and river engineering. Our recent study is focused on flow metrics that best describe the registered flow regime and hydrological characteristics of rivers within the Tundzha watershed located in South Bulgaria. The flow regime will be described using 5 broad categories: magnitude of river flow; frequency; duration; timing and rate of change. A special attention in the research was given to the low flows. Thirteen hydrometrics stations were selected fo...

The main goal of presented study is a demonstration of technological approach to determine the water resources of surface water bodies, using a sparse hydrological monitoring network not covering many of them. Resource of the water body is a flow formed in the catchment area above the studied one including the additional inflow in the frame of the same water body. Practically the flow is changing in each sector of the water body but average annual resources are specified at the final section. The water resources f...

Floods are natural phenomena which cannot be prevented. In order to avoid and reduce the adverse impacts of floods for human health, the environment, cultural heritage and economic activity it is important to provide flood risk management plans. Development of flood risk management plans under Directive 2007/60/EC are elements of integrated river basin management. For the implementation of Directive 2007/60 / EC, Member States need to carry out a preliminary flood risk assessment based on available or readily deri...

The lack of direct measurements (the most accurate way to determine characteristic high flows) has posed the need to look for other hydrological methods that are sufficiently reliable. The regionalization is an indirect hydrological approach for specific high flow determination used at ungauged river stretches. Usually the hydro-technical constructions or other important economic activities connected to the water use are the main reason necessitating the study of characteristic high water on rivers. For the purpos...

Modeling is important for river system analysis and management. The aim of the research is to apply disaggregation models to data with recovered natural river flow of Osam River located in North Bulgaria. As a result river discharge synthetic sequences are generated on monthly and seasonal discretization. We want to test applicability of the models for specific climatic, hydrological and orographic conditions in Bulgaria. Disaggregation models are from the family of stochastic models. Disaggregation models could b...

Determination of the maximal run off in the constantly changing urbanized territory often is very different compare to the natural conditions. There are many approaches to reflect the new conditions of flows formation including the extremes. Sometimes the level of urbanization is so quick that the conditions of flows formation could be altered in the frame of several years. The determination of the maximum flows is additionally complicated in case there is not a suitable hydrological monitoring network or a lack o...

The management of protected territories in Bulgaria is a subject to the Bulgarian and European environmental legislation. The used plans for management provide basic information on the condition of abiotic and biotic components of the natural environment in the protected territories and Guidelines for their management, control and conservation. The water resources with their specificity and dynamics of alteration are a major abiotic component that impacts on functioning, development and conservation of ecosystems ...