Abstract
Changes in soil and water salinity pose critical challenges to agriculture, water management, and livelihoods in deltaic environments globally, and particularly in the densely populated Asian mega-deltas. Using observations from 24 stations over nearly two decades (2004–2022) in the Ganges-Brahmaputra-Meghna delta of Bangladesh, our scientific study examined the influences of local weather, tropical cyclones, and hydrology on the seasonal variability in soil and river-water salinity. We applied statistical analyses including cross-correlation, seasonal trends, and wavelet decomposition, to explore the spatiotemporal dynamics of soil and river-water salinity. We developed statistical models to assess how hydrological, meteorological, and climatic factors explain its variability. Pronounced seasonal fluctuations in soil and river-water salinity are observed, with levels rising during the dry season and declining sharply during the monsoon season. We also observed how tropical cyclones contribute to short-term spikes in surface water surface water salinity, with stronger impacts observed for those making a landfall during early monsoon period (April‒May). Statistical models reveal a significant positive association between soil and surface-water salinity and sea-surface salinity during the pre-to-early monsoon season. In contrast, the seasonal rise in sea levels during the monsoon coincides with reduced soil and river-water salinity due to monsoon rainfall and freshwater discharges to the sea.
Details
Presentation Type
Paper Presentation in a Themed Session
Theme
KEYWORDS
SOIL AND WATER SALINITY, SEASONALITY, CYCLONES, CLIMATE ADAPTATION, BANGLADESH
