AbstractThis papers refers to demographic processes in the period from the 19th century through to the present and tries to define what they will look like in the future. Demographic trends i.a. relating to fertility, mortality, migrations, the process of family-union-household formation and dissolution, and the process of population ageing, are described by the concepts of demographic transformations: first, second and third. The transformation of demographic trends has coexisted and will coexist with globalization processes, though the scope of the mutual influence changes over time. Despite the fact that it takes place in various geographical regions, the transformation of demographic trends is characterised by high cultural diversity and socio-economic development.
AbstractThis paper covers work intended to study the interplay of sedimentary dynamics and climatic variability over the last two millennia within Tunisia’s sebkha Souassi. Based on the Visual Core Description, and magnetic susceptibility, we date the core from sebkha Souassi to the last two millennia. Genetic grain-size distribution then provided a basis for the identification of six climatic stages, i.e. the Warming Present (WP), the Late Little Ice Age (Late LIA), the Early Little Ice Age (ELIA), the Medieval Climatic Anomaly (MCA), the Dark Ages (DA), and the Roman Warm Period (RWP). The WP stretches across the uppermost 3 cm, with a high grey scale indicating a dry climate. The Late LIA is located between 3 and 7 cm, and the ELIA between 7 and 28 cm. Intermediate values for GS indicate that this stage may be classified as moderate. The MCA spanning from 28 to 40 cm is marked by a sharp decrease in GS indicative of a wet period. The DA appear along the part between 40 and 79 cm, a shift from light to dark sediments being recorded. The RWP in turn appears between 79 and 114 cm. Based on the grain-size distribution, two low-frequency cycles were identified, indicating radical global changes in climatic conditions, differential tectonics and groundwater fluctuations. High-frequency cycles in turn attest to local modifications of climatic conditions.
AbstractThe objective of this study was to investigate the performance of streamflow in a lowland mesoscale catchment in Poland under current and future climate conditions. Simulations of hypothetical streamflow in the future climate were facilitated by meteorological data sets from ensemble simulations from all over Europe with the Regional Climate Model CLM. Projections of precipitation and air temperature for the 21st century under the SRES A1B scenario were used as an input to the hydrological model simulating streamflow at the daily time scale. The combination of relatively moderate increase of annual precipitation sum and mean air temperature might cause lower annual discharges. The possible decrease in stream water resources might be a signal of reduced subsurface recharge and land over drying processes.