Status and sustainability challenges of agricultural water usage in Bangladesh

Authors

Keywords:

virtual water transport, climate change, water security, groundwater, surface water, precipitation, drought index

Abstract

Maintaining sustainability in agricultural water usage is a critical concern particularly when the burgeoning population demands more food while adverse climate change impacts water availability. Despite this, the climate-water-crop nexus is still poorly understood in many regions throughout the globe. This study was conducted to quantify current agricultural water use in Bangladesh, one of the most climate-vulnerable countries, and to assess its sustainability challenges. The number of crops, cropping area, yield, water use, long-term daily rainfall, daily river stage and weekly groundwater level data were collected and statistically analyzed. This study revealed that the two most drought-prone northwest divisions export virtual water embedded in agricultural produce at 14086 Mm3/yr, whereas two urbanized divisions import 18477 m3/yr, to or from the national water-use budget. Only rice production consumed ~88% of the total water used in agriculture, and the dry season rice had higher water demand than the wet season rice. The water use sustainability in the two most water-exporting divisions is at great stake because total rainfall in July is decreasing significantly (2.90 mm/yr) in one division and the number of rainless days in August is significantly increasing (0.033 day/yr) in other division. Irrigated rice production will also face water scarcity because the dry season water level in both rivers (63%) and observation wells (92%) shows a declining trend. The ratio of green (rainfed) to blue (irrigation) water use in the country was estimated at 2.5, which needs to be increased.

Author Biography

M. G. Mostofa Amin, Bangladesh Agricultural University

Professor

Department of Irrigation and Water Management

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Published

2021-09-26

Issue

Section

I-Land and Water Engineering