Identifying the Threshold Level of Flooding for Rice Production in Bangladesh: An Empirical Analysis

Mohammad Rahman,Md Sarkar,Md Rahaman,Mohammad Islam,Md Kabir,Rokib Ahmed

doi:10.5455/jbau.53297

Abstract

Flood is responsible for the agricultural production scheme and livelihood well-being in Bangladesh. It is the most frequent catastrophe that affects crop production in terms of area coverage and yield. However, a normal flood is beneficial for the ecology and environment. As rice is the most important crop for sustaining the food security of the country, this study identified the threshold level of flooding for rice area coverage and production. The study used the time series data of annual rice area coverage, production, and flooding area in a well-established threshold regression model. The empirical results expose that flooding 22 percent of the geographical area is the threshold value for rice area coverage and production in Bangladesh. Up to the threshold level (22 percent), a one square kilometer increase in flooding would increase the rice area coverage by 31 hectares, as flooding would bring more land under cultivation. Beyond the threshold limit, a one square kilometer increase in flooding would reduce the rice area coverage by 2 hectares. On the other hand, the production of rice would increase by 492 tons with a one square kilometer increase in flooding up to the threshold limit. However, the rice production would reduce by 70 tons if a one square kilometer increase flooding above the threshold limit. On top of that, both the rice area coverage and production showed increasing trends with the increase in flooding level in the last few years. The reasons behind this aregovernment supports, subsidies, incentives, and stress coping strategies towards accelerating national production to overcome the effects of the flood to sustain national food security; development of stress-tolerant and high yielding modern rice varieties by the research organizations; and replacing the local varieties with these modern varieties by the farmers and extension workers in Bangladesh.

Highlights

Bangladesh exists between 20o30’ and 26o40’ north latitude, and 88o03’ and 92o40’ east longitude of the globe
Concept of flood and production nexus Flood impacts rice production in two sequential ways. It affects the rice area coverage and yield, both of these have a direct impact on rice production (Hassan, 2019)
In order to estimate the threshold, we minimize the least squares of the following regression of T observations and two regions, Threshold regression: identifying threshold flooding level and the consequences of flood on rice area and production

Summary

Introduction

Bangladesh exists between 20o30’ and 26o40’ north latitude, and 88o03’ and 92o40’ east longitude of the globe It is one of the world's largest functional deltas with an area of about 1,47,570 square kilometers (FFWC, 2019). The country is in a subtropical monsoon climate; the annual usual rainfall is approximately 2,300 mm, ranging from 1,200 mm in the northwest to above 5,000 mm in the northeast (FFWC, 2019). It has 405 rivers, 57 of which are trans-boundary, 54 of which originated in India including three main rivers - the Ganges, the Meghna, and the Brahmaputra. The main causes of flooding in Bangladesh mentioned in Choudhury and Chairman (2001) are- i) access rainfall, ii) Himalayan snow melting, iii) Brahmaputra basin's hydrographic changes, iv) every year, 2.4 billion tons of sediments transported by Bangladesh's river flow, decreases the water carrying ability of rivers, which aggravates flooding, v) deforestation in catchment areas tends to worsen flooding, and vi) construction of unplanned roads, highways, dams, embankments, etc. often build barriers to water flow and aggravate flooding

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