Search Results (2)

Riverbed dynamics are natural processes that are strongly driven by human and climatic factors. In the last two centuries, the anthropogenic influence and impact of climate change on European rivers has resulted in significant degradation of riverbeds. This research paper aims to determine the historical evolution (1856–2021) and future trends of the Ialomița riverbed (Romania) under the influence of anthropogenic impact and climate change. The case study is a reach of 66 km between the confluences with the Ialomicioara and Pâscov rivers. The localisation in a contact zone between the Curvature Subcarpathians and the Târgoviște Plain, the active recent tectonic uplift of the area, and the intense anthropogenic intervention gives to this river reach favourable conditions for pronounced riverbed dynamics over time. To achieve the aim of the study, we developed a complex methodology which involves the use of Geographical Information System (GIS) techniques, hierarchical cluster analysis (HCA), the Mann–Kendall test (MK), and R programming. The results indicate that the evolution of the Ialomița River aligns with the general trends observed across Europe and within Romania, characterised by a reduction in riverbed geomorphological complexity and a general transition from a braided, multi-thread into a sinuous, single-thread fluvial style. The main processes consist of channel narrowing and incision alternating with intense meandering. However, specific temporal and spatial evolution patterns were identified, mainly influenced by the increasingly anthropogenic local influences and confirmed climate changes in the study area since the second half of the 20th century. Future evolutionary trends suggest that, in the absence of river restoration interventions, the Ialomița riverbed is expected to continue degrading on a short-term horizon, following both climatic and anthropogenic signals. The findings of this study may contribute to a better understanding of recent river behaviours and serve as a valuable tool for the management of the Ialomița River. Full article

Changes in land use and agricultural landscapes are primarily the result of socio-political and economic changes. This research is based on the analysis of old maps, pertaining to different historical periods, aiming to capture the dynamics of the landscape in the Central Bărăgan Plain. The cartographic materials used have the Map of Southern Romania from 1864, the Firing Master Plans and the Corine Land Cover dataset (1990, 2000, 2018) as reference. For the case studies, these sources are supplemented by the orthophotoplan from 2012 and the remotely-sensed image acquired by Corona satellites in 1974. The results highlight the fact that between 1864 and 2018, the Central Bărăgan Plain recorded important changes in land resources. The most significant transformations took place in the period between 1864 and 1959, when 58% of the plain area was purposed for another use in that large areas of land were introduced in the agricultural use. If in 1864 the agricultural lands represented less than half (196.896 ha) of the Central Bărăgan area, the natural areas being dominant (201.473 ha), in the first half of the 20th century, they increased exponentially (361.674 ha), the natural vegetation occupying much smaller areas (28.481 ha) mainly along the Ialomița and Călmățui rivers and near lakes. This trend is also expressed by the values of the index of naturalness which shows a drastic decrease, from 51.7% in 1864, to 10.6% in 1916–1959. There is also an increase of the area cover by settlements which should be explained by the occurrence of new villages and the increase in size of the existing villages. Another result of the approach concerns the changes that occurred in the agricultural landscape in the middle, respectively at the end of the 20th century, which is a fact quantified by computing the index of land fragmentation. The dynamics of land use and the changes in the features of the agricultural landscape, as far as the analyzed area is concerned, are due to the agrarian reforms pertaining to different historical periods, as well as to the forced relocations during the communist regime. Therefore, the study aims to highlight changes during historical, socio-economic and political time in land use and to reduce the degree of naturalness of the territory at the same time. Full article