EVOLUTION OF SOILS LOCATED ON SLOPE IN THE VALEA CU DRUM HYDROGRAPHIC BASIN IN BUZĂU COUNTY UNDER THE INFLUENCE OF EROSION AND ANTHROPOGENIC INTERVENTION, UNDER CURRENT CLIMATE CHANGE CONDITIONS

Abstract

The paper aims to present the evolution of soils located on slope over 24 years by comparing data obtained through successive mapping in 2000 and 2024.The research aimed to characterize the soils in the upper third of the Valea cu Drum hydrographic basin, located on the right slope of the Slănic stream in Buzău county. Two successive pedological mappings were carried out in this area in 2000 and 2024. The soils in the studied area fall into two classes according to the Romanian Soil Taxonomy System: Chernozems ( luvic Chernozems and haplic Phaeozems) and Anthrosols (calcareous Anthrosols). These three soil types have the highest share in the hilly area of Buzău County. In the upper third of the left slope of the studied watershed, wide terraces were built between 1993 and 1996, with the following dimensions: platform height of 12 m, height of embankment and cut-off of 2.3 m, platform slope ip=10%, excavation volume (Vfill) was equal to that of filling (Vfill) of 10 m3/ ml with the aim of reducing soil losses through erosion. Through the pedological mapping carried out in 2024, the three main profiles were opened, in which the pedogenetic horizons were delimited through morphological analysis carried out in the field and soil samples were collected from each pedogenetic horizon for laboratory analysis: granulometric analysis, reaction, carbonate and humus content.
The June-September 2024 interval is characterized by higher temperatures and lower precipitation, which characterizes a dry year from a climatic point of view. The air temperature values during the vegetation period recorded in 2024 are higher by 1oC in June, by 2.4oC in July, by 3oC in August and by 5.4oC in September compared to those recorded in 2000. Lower air temperature values in 2024 compared to those in 2000 were recorded in April by 1.4oC and in May by 3.6oC. The total amount of precipitation that fell during the vegetation period in 2000 is 321.6 mm compared to 247.3 mm in 2004, a difference of 74.3 mm showing a deficit of precipitation in 2024.
The calcareous Anthrosols profile was located in the upper third of the terraced left slope, on the platform of the T2 terrace in the clearing, and has the profile: Aho-Ck. The haplic Phaeozems profile was located on the right slope of the watershed with hay use, having the profile: Amtk-ACk-Ck1-Ck2. The soil is slightly eroded. The luvic Chernozems profile was located on the left slope of the watershed and has the profile: Aom-AB-Bt1-Bt2-C, the soil is moderately eroded.