Investigation of the effect of anthropogenic land use on the Pănăzii Lake (Romania) catchment area using Cs-137 and Pb-210 radionuclides

Abstract

The problem of soil degradation has accentuated over recent decades. Aspects related to soil erosion and its relation to changes in land use as well as anthropogenic influence constitute a topic of great interest. The current study is focused on a soil erosion assessment in relation to land use activities in the Pănăzii Lake catchment area. Fallout radionuclides were used to provide information on soil erosion as well as redistribution rates and patterns. Variations in the sedimentation rate of the lake were also investigated as these reflect periods in which massive erosion events occurred in the lake catchment area. The novelty of this study is the construction of a timescale with regard to the soil erosion events to better understand the relationship between soil erosion and land use activities. In this study, 10 soil profiles and one sediment core from the lake were taken. Soil parameters were determined for each sample. The activities of 210Pb, 137Cs and 226Ra were measured by gamma spectroscopy. For low 210Pb activities, measurements via 210Po using an alpha spectrometer were performed. Soil erosion rates were determined by the 137Cs method and the sedimentation rate calculated by the Constant Rate of Supply (CRS) model. A soil erosion rate of 13.5 t·ha-1·yr-1 was obtained. Three distinct periods could be observed in the evolution of the sedimentation rate. For the first period, between 1880 and 1958, the average deposition rate was 9.2 tons/year, followed by a high deposition period (1960–1991) of 29.6 tons/year and a third period, consisting of the last 30 years, during which the sedimentation rate was 15.7 tons/year. These sedimentation rates fluctuated depending on the main land use activity, which can also be seen in the soil erosion rates that had almost doubled by the time agricultural activities were performed in the area.

Geospatial analysis of factors driving gully erosion: a case study from Southeastern Nigeria

“…3b) also corroborated with the correlation analysis results. The ndings from the results did not correspond with works of other authors on the impact of population densities on gully erosion, such as Olaniya et al ( 2020) and Begy et al (2021).The reason for the observed anomaly could be because the gullies predated the human population growth; thus areas with high frequency of gullies where naturally avoided due to its proneness to geohazard occurrence. This assumption could only be proved if time steps of the gully formation could be ascertained as way back as possible before urban development of the study area; which could be an impossible task.…”

Investigation of the last two centuries sedimentation dynamics in high-altitude lakes of Southern Carpathians, Romania

“…Proposed by Goldberg 10 in 1963 and first applied in lacustrine sediments by Krishnaswamy et al, in 1971 11 , the technique is based on the decay curve of atmospherically deposited 210 Pb, found in excess with respect to its parent radionuclide, 226 Ra, in sediment cores. The high temporal resolution chronologies of recent lake deposits enable the comprehensive study of the SRs trends and high sedimentation events recorded in the analyzed cores 12 . The temporal applicability of the 210 Pb technique is most relevant due to its coverage of both the industrial revolution and the Modern Warm Period (MWP), during which significant natural and anthropic changes occurred globally.…”