Saline Soils Areas Variability Evaluation through Remote Sensing Techniques - Case Study Socodor ATU, Romania

Abstract

The study used remote sensing techniques to analyze the variability of an area affected by salinity soils. The study area was within the Socodor ATU, Arad County, Romania. Satellite scenes were acquired in the Sentinel 2 system, in the summer season, June and July, between 2020 and 2024. The Brightness Index (BI), Salinity Index (SI), Salinity Index 2 (SI2) and Normalized Salinity Index (NDSI) were calculated based on the spectral data. A very strong positive correlation was recorded between SI2 and BI throughout the study period (p<0.001). At the level of the other indices, the correlation presented variable levels of intensity. Differences were recorded between the values ​​of the indices during the study period. High values ​​of the SI, SI2 and BI indices were recorded in 2022, compared to 2020 and 2024 (p<0.001). In the case of the NDSI index, higher values ​​were recorded in 2020 (p<0.001). The variation of the BI index in relation to SI2 was described by a polynomial mathematical model, with with a very strong positive correlation, p = 0. In relation to the principal components, there was a differentiated positioning of the indices in the case of 2020 compared to 2022 and 2024, and a high degree of similarity regarding the positioning of the indices in 2022 and 2024. In 2020, the NDSI, BI and SI2 indices were positioned in PC1, with very strong positive action, and the SI index was positioned independently. In the case of the years 2022 and 2024, the BI and SI2 indices were positioned in PC1 with very strong positive action, and the SI and NDSI indices were positioned in PC2, with very strong positive action (the SI index), and strong negative action for the NDSI index (2022), respectively moderate negative action for the NDSI (2024).