The adverse impacts of climate change exert mounting pressure on agriculture-dependent livelihoods of many developing and developed nations. However, integrated and spatially specific vulnerability assessments in less-developed countries like Bangladesh are rare, and insufficient to support the decision-making needed for climate-change resilience. Here, we develop an agricultural livelihood vulnerability index (ALVI) and an integrated approach, allowing for (i) mapping out the hot spots of vulnerability distribution; (ii) identifying key factors of spatially heterogeneous vulnerability; and (iii) supporting intervention planning for adaptation. This study conceptualized vulnerability as a function of exposure, sensitivity, and adaptive capacity by developing a composite index from a reliable dataset of 64 indicators comprising biophysical, agro-ecological, and socioeconomic variables. The empirical studies of coastal Bangladesh revealed that Bhola, Patuakhali, and Lakshmipur districts, around the mouth of the deltaic Meghna estuaries, are the hot spot of vulnerability distribution. Furthermore, the spatially heterogeneous vulnerability was triggered by spatial variation of erosion, cyclones, drought, rain-fed agriculture, land degradation, soil phosphorus, crop productivity, sanitation and housing condition, infant mortality, emergency shelters, adoption of agro-technology. The integrated approach could be useful for monitoring and evaluating the effectiveness of adaptation intervention by substituting various hypothetical scenarios into the ALVI framework for baseline comparison.

Assessing the effects of different land use scenarios on subsequent changes in ecosystem service has great implications for sustainable land management. Here, we designed four land use/land cover (LULC) scenarios, such as business-as-usual development (BAUD), economic development priority (EDP), ecological protection priority (EPP), and afforestation development priority (ADP), through a Cellular Automata-Markov (CA-Markov) model, and their effects on ecosystem service values (ESVs) were predicted, using historical LULC maps and ESV coefficients of the Lower Meghna River Estuary, Bangladesh. Findings revealed that agricultural and mangrove forest lands experienced the greatest decreases, while rural and urban settlement land had the greatest increases, leading to a total ESV decrease of US$105.34 million during 1988-2018. The scenario analysis indicated that ESV in 2038 would also decrease by US$41.37 million and US$16.38 million under the BAUD and EDP scenarios, respectively, while ESV will increase by US$60.61 million and US$130.95 million under the EPP and ADP scenarios, respectively. However, all the future land use scenarios will lead to 1.65%, 10.21%, 7.58%, and 6.75% gaps in total food requirements, respectively. Hence, from the perspective of maximizing ESVs and minimizing the trade-offs in food gaps, the ADP scenario could be the optimal land management policy for the studied landscape.

While land reclaimed from the sea meets the land demand for coastal development, it simultaneously causes socio-economic systems to be prone to coastal flooding induced by storm surges and sea-level rise. Current studies have seldom linked reclamation with coastal flood impact assessment, hindering the provision of accurate information to support coastal flood risk management and adaptation. This study, using Xiamen, China as a case study, incorporates the spatiotemporal dynamics of reclamation into a coastal flood impact model, in order to investigate the long-term influence of reclamation activities on coastal flood inundation and the consequent exposure of the population to coastal flooding. We find that rapid population growth, continual economic development and urbanization drive a substantial logarithmic increase in coastal reclamation. Historical and future expansions of seaward land reclamation are found to cause dramatic surges in the expected annual inundation (EAI) and the expected annual population (EAP) exposed to coastal flooding. In Xiamen, EAI is estimated to increase by 440.2% from 1947 to 2035, owing to continuing land reclamation. Consequently, the population living in the flooded area has also increased sharply: the EAP of total population is estimated to rise from 0.8% in 1947 to 4.7% in 2035, where reclamation contributes over 80% of this increase. Moreover, a future 10 cm sea-level rise in 2035 will lead to extra 5.73% and 8.15% increases in EAI and EAP, respectively, and is expected to cause massive permanent submersion in the new reclamation zone. Our findings emphasize an integration of hard structures and nature-based solutions for building resilient coasts.