Exploring the Potential of Soil Salinity Assessment through Remote Sensing and GIS: Case Study in the Coastal Rural Areas of Bangladesh

Abstract

Soil salinity is a negative impact of climate change, and it is a significant problem for the coastal region of Bangladesh, which has been increasing in the last four decades. The issue of soil salinity substantially limits the agricultural crop production in coastal areas. Therefore, a soil salinity assessment is essential for proper land-use planning in agricultural crop production. This research was carried out to determine the soil salinity area with different salinity levels in Barguna Sadar Upazila (sub-district). The remote sensing technique, which is a potentially quick yet effective method for the soil salinity estimation in data-scarce conditions, was applied. The methodology employed the Landsat 8 OLI dataset along with nine soil salinity indices to develop a soil salinity map. The maps were from Soil Resource Development Institute (SRDI), and low NDVI value (−0.01 to 0.48) was produced using satellite images illustrate the extent of the soil salinity for the study area. However, nine linear regressions, which were made between the pixel value of the satellite-based generated map and ground truth soil salinity data, that is, the EC value, indicate a maximum R2 value for the salinity index SI 7 = G×R/B, representing a value of 0.022. This minimal R2 value indicates a negligible relationship between the ground EC value and the pixel value of the salinity index generated map, inferring that the indices are not sufficient to assess the soil salinity. Nonetheless, this research’s findings offer a guide for researchers to investigate alternative geospatial approaches for this geophysical condition.

Assessment of the Hydrological Conditions of Carps Spawning Grounds in the Sylhet Haor Basins, and the Halda River System, Bangladesh

“…The range provided by Bhatnagar and Devi [46] does not result in a decreased rate of fish breeding; the acceptable and optimal TDS values are 2000 mg/L and 500 mg/L, respectively. According to Hossen et al [50], the Halda River introduces the most salt intrusion during the dry season, while in the rainy season, the rainwater dilutes the salinity. Salinity incursion is most noticeable between January and March, and less so between April and July [51].…”

Challenges and Opportunities in Remote Sensing for Soil Salinization Mapping and Monitoring: A Review

“…A comparative study conducted by the authors of [131] between a physical model and three ML models, including distributed random forest (DRF), gradient boosting machine (GBM), and deep learning (Deeplearning) for salinity estimation at the canopy scale, found that machine learning-based models have predictive power similar to physical-based models; however, their performance primarily depends on the prediction scenarios and input variables. In the coastal rural areas of Bangladesh, research was carried out by the authors of [132] to explore the potential of salinity using Landsat 8 OLI data. The study used various vegetation and salinity indices in a linear regression analysis-based approach to determine the statistical association between these indices and ground-measured electrical conductivity to yield a low correlation between the ground EC and the pixel values of generated maps, suggesting that the indices are not sufficient to assess salinity.…”

Hydroponic Screening at Early Seedling Stage Identified Sources of Salinity Tolerance in Wheat (Triticum aestivum L.) Crop

“…Most of these lands are located in arid and semi-arid areas, in North Africa, East Asia, Central Asia and South Asia [6]. Their proportion is notably high in the near East (Egypt, Algeria, Tunisia), Middle East (Iran, Pakistan, Bangladesh), Central Asia (Uzbekistan), Northern China and Argentina [7][8][9][10][11][12][13][14]. Sodic soils are particularly widespread in Australia, but also in certain specific situations, such as in Hungary and Uzbekistan [15].…”