Volume XIII |

Estimation of the Quaternary stream erosion in small drainage basins (Vâlcea sub-Carpathians and Olteţ Plateau, Romania)

Abstract: Stream erosion is a widely spread process in the Getic sub-Carpathians and Plateau (including the study sub-units). It is controlled by the high density of small drainage basins on a surface unit. Development of the 4th and 5th order valleys (according to Strahler’s system) in the sub-Carpathians and of the 3rd and 4th order in the Olteţ Plateau was also determined by the high altitude of hillslopes, up to 450 meters in the Vâlcea sub-Carpathians and to 250 meters in the Olteţ Plateau, a consequence of the strong downcutting performed by the Olt river and its main tributaries in this area (Olăneşti, Bistriţa, Cerna and Olteţ). Another control factor is the friable bedrock made of sedimentary deposits: conglomerate, gravel, sand, sandstone, marl, clay, tuffs etc. in the Vâlcea sub-Carpathians and Cândeşti strata (gravels with clayey lens of Villafranchian age) in the Olteţ Plateau.

Volume IX |

The Analysis of Forest Dynamics within the Carpathians – The Subcarpathians Contact Area by Using the Historical Cartography Approach and Open Source GIS Software. Case Study: The Limpedea Catchment (Romania)

Abstract: The paper is an original contribution based on the diachronic comparison of historical maps from different periods, with the purpose of capturing and mapping the landscape history of the Limpedea catchment (tributary of the Argeş), which stretches almost equally into the strongly man-altered space of the Subcarpathians, as well as into the mountain area. The study highlights the changes undergone by the Arefu – Corbeni Subcarpathian depression and the neighbouring mountain area, paying particular attention to the Carpathian – Subcarpathian interface zone. In order to achieve its goal, the study relied on large scale maps from the 1790-1980 period, which were processed in Open Source GIS (Quantum GIS, GRASS, gvSIG Sextante, MapAnalyst). The interpretation of cartographic information using GIS techniques showed a continuous recession of the forests in the Subcarpathian part of the catchment and their replacement by agricultural lands, which led to a gradual decrease of the naturality degree. In the 1864-1904 period, the extension of pastures and hay fields to the detriment of the forests was prevalent, whereas in the second half of the 20th century larger and larger areas of pastures and hay fields were turned into orchards or built-up areas.