Monitoring of the hydrological regime of the Saratov reservoir using the MNDWI index

Abstract

The article analyzes the possibilities of using Earth remote sensing (ERS) indices for monitoring the state of the environment. The possibility of using remote sensing indices for monitoring and forecasting the state of water bodies and watercourses, their hydrological characteristics was assessed. Within Samara region, the possibility of using the Modified Normalized Difference Water Index (MNDWI) to assess the water saturation of the Saratov reservoir in the Vasilievsky Islands area was considered. This territory was chosen due to the fact that it is sufficiently indicative for assessing changes in the hydrological regime of the reservoir. The processing of multispectral images taken by the Sentinel-2 satellite was carried out on the basis of green and short-wavelength spectral channels. The area of the water surface was calculated based on the number of binary pixels of the processed images. In accordance with the calculations, it was revealed that the area of the Saratov reservoir in the Vasilievsky Islands area has increased. At the same time, it was noted that the area of the water surface of small water bodies that have no connection with the reservoir has increased. The results obtained showed a high efficiency of monitoring changes in the hydrological regime of the reservoir when using the MNDWI.

Mapeamento de áreas inundadas usando um índice de água baseado em dados do satélite Sentinel-2: as cheias de 2019 no Baixo Mondego (Portugal)

“…Por meio da obtenção de imagens de satélite Sentinel-2, disponibilizadas pelo Programa Copernicus, e do mapeamento de áreas inundadas com recurso ao MNDWI, é possível monitorizar a dinâmica da evolução quanto à extensão da área inundada e usar essa informação no planejamento de intervenções no terreno, enquanto o próprio evento de inundação está a decorrer. O mapeamento de superfícies terrestres com água (e.g., massas de água, áreas inundadas) recorrendo ao MNDWI mostra resultados promissores, tal como se verificou em estudos anteriores (DU et al, 2016;SOLOVEY, 2020;SHERSTOBITOV et al, 2021;SIVANPILLAI et al, 2021).…”

Editorial

“…Por meio da obtenção de imagens de satélite Sentinel-2, disponibilizadas pelo Programa Copernicus, e do mapeamento de áreas inundadas com recurso ao MNDWI, é possível monitorizar a dinâmica da evolução quanto à extensão da área inundada e usar essa informação no planejamento de intervenções no terreno, enquanto o próprio evento de inundação está a decorrer. O mapeamento de superfícies terrestres com água (e.g., massas de água, áreas inundadas) recorrendo ao MNDWI mostra resultados promissores, tal como se verificou em estudos anteriores (DU et al, 2016;SOLOVEY, 2020;SHERSTOBITOV et al, 2021;SIVANPILLAI et al, 2021).…”

MST-UNet: a modified Swin Transformer for water bodies’ mapping using Sentinel-2 images

“…Threshold-based method is to determine the appropriate threshold value to complete water and land segmentation by expanding difference between spectral features of water bodies and background pixels, such as single-band thresholding method, 4 which only selects near-infrared (NIR) band in remote sensing data to set threshold value, the normalized difference water index (NDWI), 5 which is based on green band and NIR band, and the modified NDWI 6 , 7 replaces NIR band with mid-infrared band.…”