Evolutionary social and biogeophysical changes in the Amazon, Ganges–Brahmaputra–Meghna and Mekong deltas

Abstract

Policy-making in social-ecological systems increasingly looks to iterative, evolutionary approaches that can address the inherent complexity of interactions between human wellbeing, provision of goods and the maintenance of ecosystem services. Here, we show how the analysis of available time-series in tropical delta regions over past decades can provide important insight into the social-ecological system dynamics in deltaic regions. The paper provides exploratory analysis of the recent changes that have occurred in the major elements of three tropical deltaic social-ecological systems, such as demography, economy, health, climate, food, and water. Timeseries data from official statistics, monitoring programmes and Earth observation data are analysed to explore possible trends, slow and fast variables, and observed drivers of change in the Amazon, Ganges-Brahmaputra-Meghna and Mekong deltas. In the Ganges-BrahmaputraMeghna delta zone, increasing gross domestic product and per capita income levels since the 1980s mirror rising levels of food and inland fish production. In contrast, non-food ecosystem services, such as water availability, water quality and land stability appear to be deteriorating. In the Amazon delta, natural and anthropogenic perturbations are continuously degrading key ecosystem services, such as carbon storage in biomass and soils, the regulation of water balance, and the modulation of regional climate patterns. In the Mekong delta, rapid economic development, changing land use practices and salinity intrusion, are progressively putting more pressure on the delivery of important provisioning services, such as rice and inland aquaculture production, which are key sources of staple food, farm incomes and export revenue. Observed changes in many key indicators of ecosystem services point to a changing dynamic state and increased probability of systemic threshold transformations in the near future.

Drivers of change and adaptation pathways of agricultural systems facing increased salinity intrusion in coastal areas of the Mekong and Red River deltas in Vietnam

“…Recent developments in the agricultural systems e.g. integrated farming systems in the brackish and saline water zones in the MKD corresponded to adaptation strategies of increased connectivity of the systems to the global market in order to diversify the income sources and buffer the high volatility to fluctuation of market prices (de Araujo Barbosa et al, 2016).…”

“…Global deltaic coastal zones are facing dynamic changes mainly driven by sea level rise and human activities that modify deltas' catchment characteristics such as deforestation, largescale hydraulic development and land use conversion (Syvitski et al, 2005). These changes in land use can impact the stability of the coastal zones and global and regional climates through alteration of carbon cycles, soil degradation, declines of biodiversity, and changes in the provision of ecosystem services (de Araujo Barbosa et al, 2016;Lambin et al, 2006).…”

Resilience of agricultural systems facing increased salinity intrusion in deltaic coastal areas of Vietnam

“…In addition, agricultural systems in the deltas are currently exposed to multiple social and environmental stressors from water-related hazards, social-economic transitions, and market volatility (Cong et al 2009, de Araujo Barbosa et al 2016.…”

The rationality of groundwater governance in the Vietnamese Mekong Delta’s coastal zone

“…The VMD could see much of its area subjected to both tidal and upstream-induced floods and to saltwater intrusion, threatening even more arable land (Smyle & Cooke, 2014). Consequently, food security will be at high risk (de Araujo Barbosa et al, 2016;Ericson et al, 2006). Knowledge of groundwater, however, is only available to a limited extent in the region.…”