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Understanding Volumetric Water Storage in Monsoonal Wetlands of Northeastern Bangladesh
Author(s) -
Ahmad Shahryar Khalique,
Hossain Faisal,
Pavelsky Tamlin,
Parkins Grant M.,
Yelton Sarah,
Rodgers Megan,
Little Sarina,
Haldar Debolina,
Ghafoor Sheikh,
Khan Raihanul Haque,
Shawn Nazmul Ahsan,
Haque Aminul,
Biswas Robin Kumar
Publication year - 2020
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2020wr027989
Subject(s) - wetland , environmental science , water storage , monsoon , bathymetry , hydrology (agriculture) , surface runoff , water balance , surface water , ecosystem , geography , oceanography , ecology , meteorology , geology , environmental engineering , geotechnical engineering , inlet , biology
The volume of water stored in seasonal wetlands is a fundamental but difficult to measure variable for developing a physical understanding of wetland behavior. For seasonal wetlands that are a major source of water for rice and fish production, this physical understanding is key to planning for water‐food security and ecosystem services. This study quantified variations in volumetric storage for the numerous seasonal wetlands of northeastern Bangladesh, locally known as “haors.” These haors receive transboundary runoff from densely vegetated and mountainous terrain in India and face persistent monsoonal cloud cover as they become full. We estimated volumetric storage for 13 haors by using extensive remote sensing data on water surface extent and elevation that was complemented with citizen‐contributed gauge data. Assuming a trapezoidal bathymetry, an area‐volume relationship was developed for selected haors. This relationship was assumed to be valid for extrapolating volumetric estimations over all the haors in the region. Results suggested that as haors get filled with the onset of monsoon rains, total estimated storage relative to the lowest observable level varied from 6.5 (±0.4) km 3 in May to 30.9 (±2.0) km 3 in July (peak of monsoon). Choosing a rectangular bathymetry can lead to 47% higher estimates compared to trapezoidal cross section. Estimating this intra‐annual/interannual increase in storage is important for the region to plan water management policies that balance the human and ecosystem needs. Our analytical approach has potential for application to wetlands worldwide in light of the upcoming Surface Water and Ocean Topography (SWOT) mission.