Impacts of cyclone and flood on crop and fish production in disaster prone coastal Bhola district of Bangladesh

This study assessed the impact of climate change induced disaster on crops and fisheries production at Bhola Sadar and Monpura upazila of Bhola district, Bangladesh during January to June 2018. The study was gathered primary data from primary observation (PO), questionnaire survey (QS), focus group discussion (FGD), and key informant interview (KII). Secondary data were collected from Upazila Agricultural Office and Upazila Fisheries Office of Bhola Sadar and Manpura upazila and moreover, climatic data were collected from Bangladesh Meteorological Department. Results of the study found that trend analysis indicates overall annual maximum temperature increased for Kharif-I, Kharif-II and Rabi season. Average annual minimum temperature also increased for Kharif-I season but decreased for Kharif-II and Rabi season. Study also found that for all cropping season average relative humidity was increased. Annual average rainfall exhibited decreasing trend for Kharif-I and Rabi season but increased for Kharif-II season in (1990-2019) time period. The Aus, T. Aman, Boro and Mung bean was dominant cropping pattern in Kharif-I, Kharif- II and Rabi season in Bhola district. Overall, Aus rice production in Kharif-I season increased but in 2009, 2013 production was decreased because of cyclone Aila (2009) and Cyclone Mahasen (2013). T. Aman production hampered due to Cyclone Sidr (2007) and flood (2014) in Kharif-II season. In Rabi season Boro rice production lessen because of low rainfall and salinity intrusion. Overall, Mung bean production increase but in 2008 and 2009 production become hampered due to late cultivation because of Cyclone Sidr (2007). Fish production rate increase in Bhola specially Hilsha fish because of non-climatic factor like raid in non-fishing time, banned current net but fish production in pond become diminished due to infrequent natural disaster. Practicing of salt and flood tolerant varieties, floating bed vegetable cultivation, and mixed cropping system (mainly for Rabi season), enhanced expedition activities against catching mother Ilish in prohibition period, dredging in the heart of the river which can eventually reduce vulnerabilities and increase crop and fish production in the Bhola region. Int. J. Agril. Res. Innov. Tech. 10(1): 40-55, June 202

Anthropogenic climate change and extreme weather events: implications for Bangladesh

Probabilistic Event Attribution (PEA) quantifies the change in risk of extreme weather events due to external drivers of climate change. The regional climate model (RCM) of the weather@home system has been successfully used for this purpose. So far, most PEA based studies have focused on extreme events of mid-latitudes and developed countries, while the events occurring in tropical regions and developing countries have gained little attention. This thesis evaluates the performance of the RCM of weather@home over the complex tropical monsoon climate region of South Asia, with particular focus on Bangladesh. In a combined process-based and performance-based evaluation process, first the model’s response to observed variability of sea surface temperatures (SSTs) are assessed. Second, the RCM’s skill to simulate the extreme events in Bangladesh is evaluated against observations. The results suggest that the RCM performs well, capturing both, influence of observed natural SST variations and extreme weather events in Bangladesh. The thesis uses large ensembles of weather@home RCM simulations for two studies. PEA is first applied to attribute contributions of past and future greenhouse gas (GHG) emissions to extreme events under current climate conditions and future warmer worlds. In accordance with the targets set out in the Paris Agreement, 1.5 and 2.0 degrees warming scenarios are investigated. Results indicate that the risk of seasonal extreme rainfall events across Bangladesh will increase with additional global warming. Anthropogenic aerosols are found to be a significant influencing factor along with GHG concentrations and large-scale temperature in determining the climate change impacts. The RCM based results are found to be consistent with the findings based on simulations from four other Atmosphere Only Global Climate Models (AGCMs) under the Half a degree Additional warming, Prognosis and Projected Impacts (HAPPI) project. PEA is secondly applied for an extreme pre-monsoon rainfall event of 2017 that occurred over north-east Bangladesh and caused flash flood and severe crop damage. According to this analysis, anthropogenic climate change is assessed to have increased the risk of such event occurring by more than a factor of 2. Findings of this thesis show that the RCM of weather@home system may provide a sufficiently reliable tool for attributing human impacts on the likelihood of extreme events over the complex tropical monsoon climate region of South Asia in general and Bangladesh in particular. Since anthropogenic climate change is found to be of crucial importance with regard to extreme weather events, the conclusions of this thesis will facilitate further attribution studies over the region and help to provide guidance for local policy makers as far as climate change adaption is concerned.</p

Risks of seasonal extreme rainfall events in Bangladesh under 1.5 and 2.0 degrees’ warmer worlds – how anthropogenic aerosols change the story

Anthropogenic climate change is likely to increase the frequency of extreme weather events in future. Previous studies have robustly shown how and where climate change has already changed the risks of weather extremes. However, developing countries have been somewhat underrepresented in these studies, despite high vulnerability and limited capacities to adapt. How additional global warming would affect the future risks of extreme rainfall events in Bangladesh needs to be addressed to limit adverse impacts. Our study focuses on understanding and quantifying the relative risks of seasonal extreme rainfall events in Bangladesh under the Paris Agreement temperature goals of 1.5 °C and 2 °C warming above pre-industrial levels. In particular, we investigate the influence of anthropogenic aerosols on these risks given their likely future reduction and resulting amplification of global warming. Using large ensemble regional climate model simulations from weather@home under different forcing scenarios, we compare the risks of rainfall events under pre-industrial (natural), current (actual), 1.5 °C, and 2.0 °C warmer and greenhouse gas only (anthropogenic aerosols removed) conditions. We find that the risk of a 1 in 100 year rainfall event has already increased significantly compared with pre-industrial levels across parts of Bangladesh, with additional increases likely for 1.5 and 2.0 degree warming (of up to 5.5 times higher, with an uncertainty range of 3.5 to 7.8 times). Impacts were observed during both the pre-monsoon and monsoon periods, but were spatially variable across the country in terms of the level of impact. Results also show that reduction in anthropogenic aerosols plays an important role in determining the overall future climate change impacts; by exacerbating the effects of GHG induced global warming and thereby increasing the rainfall intensity. We highlight that the net aerosol effect varies from region to region within Bangladesh, which leads to different outcomes of aerosol reduction on extreme rainfall statistics, and must therefore be considered in future risk assessments. Whilst there is a substantial reduction in the impacts resulting from 1.5 °C compared with 2 °C warming, the difference is spatially and temporally variable, specifically with respect to seasonal extreme rainfall events

Geophysical evidence for lithospheric delamination beneath the Alboran Sea and Rif-Betic mountains

This paper was published in Nature by the Nature Publishing Group (NPG), and NPG retains the copyright. See also: http://www.nature.com/nature/journal/v379/n6568/abs/379785a0.html; http://atlas.geo.cornell.edu/morocco/publications/seber1996Nature.htmGeophysical evidence is presented for an episode of active delamination of a piece of continental lithosphere. Observations of earthquake hypocentre locations, seismic wave velocities and attenuation, Bouguer gravity, seismic reflection, and drill hole data are combined with surface geology to infer the presence of a high-velocity, seismically active, rigid body in the upper mantle beneath the Alboran Sea and surrounding Betic and Rif mountain belts of the western Mediterranean region. This upper-mantle body, inferred to be the delaminating continental lithosphere, is overlain by a low-velocity, aseismic and strongly attenuating uppermost mantle, inferred to be the asthenospheric material replacing the delaminating lithosphere

A review of food security and the potentials to develop spatially informed food policies in Bangladesh

Background:Food security globally depends primarily on three components: food availability, food access, and food utilization. Regional variations of these components may affect food security via spatial differences in natural, social or economic conditions and the interaction of these in a complex environmental system.Purpose:It is important to understand the regional variation of food security, particularly where and under what natural and socio-economic circumstances people become vulnerable to low food security in a country.Methods:This article provides an overview of food security in Bangladesh in terms of the three main components, identifies knowledge gaps in present food security research, reviews possible impacts of climate change on food security, and sourced a wide range of spatio-temporal data relevant for food security.Results:The study highlights potentials and indicates different processes to develop spatially informed food policies in a country, particularly focuses on Bangladesh. This will contribute to improved food security by considering regional food security conditions, region-specific deficits, climate change, other future risks, and devises actions related to the respective components.Conclusion:The study concludes that different processes can provide a foundation for policy development and these will advance research-policy linkage to improved food security