Flood pattern changes in the rivers of the Baltic countries

Estimation of both the frequency and variation of spring floods is a key issue for the assessment and management of flood risks. Changes in river floods in Estonia, Latvia and Lithuania have been investigated in few national studies. However, there are no studies of the changes of flood patterns by using a common methodology for the rivers of this region. In this study flood pattern changes in the rivers of the Baltic countries were estimated applying trend and frequency analysis for the periods of 1922–2010, 1922–1960, 1961–2010 and 1991–2010, i.e. for the whole spring flood data sets, periods before and after 1960 (this year was considered as the beginning of the remarkable climate change), as well as for the two past decades. A comparative study of five probability distributions was performed in order to estimate which distribution at best represents statistical characteristics of the flood data. The results showed that maximum discharges of spring floods decreased over the whole studied period. Only some insignificant positive trends of maximum discharges were found in the last time period in continental and transitional rivers. Generalized extreme value distribution provided the best approximation to the maximum discharge data series of the rivers of Baltic countries for the whole observation period. First published online: 08 Jul 201

Development of a Harmonised Methodology for Narva River Water Discharge Estimation

The Narva River has its source in Lake Peipsi and flows into the Gulf of Finland [...

Estimation of the Share of Total Nutrient Load from the Territory of Estonia along the Narva River to the Baltic Sea

The annual inputs of nitrogen and phosphorus by the Narva river into the Baltic Sea are distributed between Estonia and Russia according to the catchment area shares of 33% and 67%, respectively [...

Application of the integrated hydrological modelling system IHMS-HBV to pilot basin in Estonia

This report describes calibration and application of the IHMS-HBV model on a daily time step to Kasari River basin in Estonia. The Swedish Meteorological and Hydrological Institute (SMHI) have as consultant been responsible for the set-up, calibration, training and delivery of the Integrated Hydrological Model System with the HBV-model (IHMSHBV). The Swedish Board for lnvestment and Technical Support (BITS) financed the project. The training and transfer of technology were addressed to the Estonian Meteorological and Hydrological Institute (EMHI)

Linking atmospheric, terrestrial and aquatic environments: Regime shifts in the Estonian climate over the past 50 years.

Climate change in recent decades has been identified as a significant threat to natural environments and human wellbeing. This is because some of the contemporary changes to climate are abrupt and result in persistent changes in the state of natural systems; so called regime shifts (RS). This study aimed to detect and analyse the timing and strength of RS in Estonian climate at the half-century scale (1966-2013). We demonstrate that the extensive winter warming of the Northern Hemisphere in the late 1980s was represented in atmospheric, terrestrial, freshwater and marine systems to an extent not observed before or after the event within the studied time series. In 1989, abiotic variables displayed statistically significant regime shifts in atmospheric, river and marine systems, but not in lake and bog systems. This was followed by regime shifts in the biotic time series of bogs and marine ecosystems in 1990. However, many biotic time series lacked regime shifts, or the shifts were uncoupled from large-scale atmospheric circulation. We suggest that the latter is possibly due to complex and temporally variable interactions between abiotic and biotic elements with ecosystem properties buffering biotic responses to climate change signals, as well as being affected by concurrent anthropogenic impacts on natural environments