scholarly journals Investigation of Forest Area Change in the 19th–21st Century Using Military Topographic Maps

2020 ◽  
Author(s):  
Rūta Puzienė ◽  
Asta Anikėnienė
Keyword(s):  
21St Century ◽  
Statistical Data ◽  
Topographic Maps ◽  
Forest Land ◽  
Land Area ◽  
Current Increase ◽  
Long Term Changes ◽  
Forest Area Change ◽  
Forest Coverage

Long-term changes of the Earth’s cover are imperceptible. Several generations change, people do not see what had been there before they were born, they do not see what happens after they are gone, meanwhile, maps preserve the image of the surroundings that was prevailing hundreds of years ago and the analysis of which allows highlighting certain occurring tendencies. The present study aims at the analysing the change in the forest coverage on the territory of Lithuania employing statistical data and analysing the change in the forest land area from the 19th c. until the 21st c. in the Elektrenai municipality using military topographic maps. During the study, digitalised archival maps and devectorised forest areas were used, and the obtained results were compared. The information provided in the maps reveals a decrease in the forest land area during during 19th–20th c. and an increase during the 20th–21st c., however, the current increase has not compensated the earlier decrease.

scholarly journals Future Changes in Wave Conditions at the German Baltic Sea Coast Based on a Hybrid Approach Using an Ensemble of Regional Climate Change Projections

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 167
Author(s):  
Norman Dreier ◽  
Edgar Nehlsen ◽  
Peter Fröhle ◽  
Diana Rechid ◽  
Laurens M. Bouwer ◽  
...  
Keyword(s):  
21St Century ◽  
Wind Wave ◽  
Regional Climate ◽  
Hybrid Approach ◽  
Wave Modelling ◽  
Long Term Changes ◽  
Mean Wave Period ◽  
Wave Conditions ◽  
Sea Coast

In this study, the projected future long-term changes of the local wave conditions at the German Baltic Sea coast over the course of the 21st century are analyzed and assessed with special focus on model agreement, statistical significance and ranges/spread of the results. An ensemble of new regional climate model (RCM) simulations with the RCM REMO for three RCP forcing scenarios was used as input data. The outstanding feature of the simulations is that the data are available with a high horizontal resolution and at hourly timesteps which is a high temporal resolution and beneficial for the wind–wave modelling. A new data interface between RCM output data and wind–wave modelling has been developed. Suitable spatial aggregation methods of the RCM wind data have been tested and used to generate input for the calculation of waves at quasi deep-water conditions and at a mean water level with a hybrid approach that enables the fast compilation of future long-term time series of significant wave height, mean wave period and direction for an ensemble of RCM data. Changes of the average wind and wave conditions have been found, with a majority of the changes occurring for the RCP8.5 forcing scenario and at the end of the 21st century. At westerly wind-exposed locations mainly increasing values of the wind speed, significant wave height and mean wave period have been noted. In contrast, at easterly wind-exposed locations, decreasing values are predominant. Regarding the changes of the mean wind and wave directions, westerly directions becoming more frequent. Additional research is needed regarding the long-term changes of extreme wave events, e.g., the choice of a best-fit extreme value distribution function and the spatial aggregation method of the wind data.

Demographic Challenges in Central and Eastern Europe in 21st Century

2015 ◽  
Vol 3 ◽  
pp. 333
Author(s):  
Arkadiusz Durasiewicz
Keyword(s):  
Eastern Europe ◽  
Research Methods ◽  
21St Century ◽  
Central And Eastern Europe ◽  
Statistical Data ◽  
Demographic Challenges ◽  
Desk Research ◽  
Descriptive Method ◽  
Research Analysis

<p><em>Due to the fact that the least favorable situation in terms of population is in the countries of Central and Eastern Europe, the article presents the demographic position of these countries, the challenges and risks associated with the demographic crisis, the existing policy guidelines for families and points to the long-term perspective to the next 60 years (graying society). The aim of this article is to present the scale of the demographic crisis but also describe the consequences associated with it, and the challenges faced by each country in the future in the relation to the aging population. The research methods used in this work is desk research, analysis and interpretation of available statistical data and descriptive method based on the available literature.</em><strong><em> </em></strong></p><p> </p>

scholarly journals Modelling Influence of River Regulation on Runoff to the Gulf of Bothnia

1996 ◽  
Vol 27 (5) ◽  
pp. 337-350 ◽  
Author(s):  
Bengt Carlsson ◽  
Håkan Sanner
Keyword(s):  
Residence Time ◽  
River Regulation ◽  
Recent Time ◽  
Land Area ◽  
Hydropower Plants ◽  
Time Period ◽  
Gulf Of Bothnia ◽  
Long Term Changes ◽  
One Year

Runoff from a land area of approximately 490,000 km2 enters the Gulf of Bothnia. This runoff is of essential importance for the flushing of the Gulf. A change in the volume of runoff effects the residence time. There are many natural as well as man made changes in the runoff, both in the form of long-term changes over many years and those occurring within one year. The most significant man made changes come from hydropower regulation. This report describes the effect on runoff from the development of the hydropower plants in Sweden and Finland by means of comparing recorded regulated runoff and simulated natural runoff. A recent time period, 1980-91, and a time period before regulation, 1925-36, were simulated. The monthly magnitudes of the redistributed flows were found to be on average 1,700 m3/s. The maximum redistributed monthly flow in May – June reached 5,000-6,000 m3/s.

scholarly journals Investigation of the Change of Wooded Aareas in Forest Land in Raudone Eldership

2021 ◽  
Vol 14 ◽  
pp. 60-68
Author(s):  
Ruta Puziene
Keyword(s):  
Climate Change ◽  
Comparative Analysis ◽  
Research Method ◽  
Forest Area ◽  
Topographic Maps ◽  
Soviet Period ◽  
Forest Land ◽  
Area Change ◽  
Forest Area Change ◽  
Global Reduction

Under the conditions of a global reduction in forest areas and climate change, it is important to preserve as many tree-covered areas as possible and understand change trends. The article purpose – aims at identifying forest area change trends of 19th-20th c. in the current forest land of the eldership Raudonė. In the research, historical topographic maps compiled during different periods, and 2019 data from the forest registry are used. The research method of a comparative analysis is employed. The change in forest areas was analysed, and forest areas that remained unchanged for 200 years were identified. The comparison of current forest areas reflected in the cadastral data and forest areas of the considered period allowed identifying the tendency of assigning land the purpose of forest land. During the research, the period with largest forest areas was determined to be the 19th c., and with the smallest – 1st half of the 20th c. During the Soviet period, forests areas were increasing, but did not achieve the same level as in the 19th c.

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