- Established an Integrated Social, Environmental, and Engineering (ISEE) framework for conducting transdisciplinary research on human-environment coupling and its social influences and impacts.
- Identified key issues linked with observed rapid changes in the physical landscape and human communities within tidal deltaplains of southwest Bangladesh – (1) embankment (polder) construction and management; (2) growth of shrimp farming and related influences; (3) water resources, their management, and household water security; (4) livelihood diversity and associated migration strategies.
- Completion of an in-depth, interdisciplinary social-physical study of the causes and consequences of a cyclone-induced embankment failure and 2-years of uncontrolled tidal flooding on a 40 km2 island; 10,000 households were displaced during this time, with an estimated 25% out-migration; This work has been the focal point of our first phase of the project, providing a detailed understanding of physical environment vulnerabilities and diverse narratives of community strategies for coping with long and short-term stressors.
Cross-cutting and Integrative Results
- Conducted 2200-household ethnosurvey for high-quality data on household adaptations to patterns and changes in environmental conditions, and related migration events. Surveys included 320 surveys of migrant households in destination cities. Ethnosurvey integrates with physical data observations and will provide input for agent-based modeling.
- Constructed regional remote-sensing vegetation phenologies with resolution down to local scale (101-102 m); Database provides sub-annual to decadal patterns in land cover variation through a 12-year MODIS EVI time series; Strong trends in shifting shrimp and agricultural land use; Dataset a principal basis for next phase of up-scaling ground-based studies and observations.
- Interannual changes in agricultural phenology throughout the lower delta suggest stepwise expansion of aquaculture to the west of Polder 32 and increasing agricultural intensification to the northeast. Several of the polders, including 32, continue to show little large scale aquaculture and only wet season agriculture.
- Our initial integrated piece from the Polder 32 research was was recently published:
Auerbach, L.W., S.L. Goodbred Jr., D.R. Mondal, C.A. Wilson, K.R. Ahmed, K. Roy, M.S. Steckler, C. Small, et al. 2015. Flood risk of natural and embanked landscapes on the Ganges–Brahmaputra tidal delta plain. Nature Climate Change 5(2): 153–157. doi:10.1038/nclimate2472
Benneyworth, L., J. Gilligan, J. Ayers, S. Goodbred, G. George, A. Carrico, R. Karim, F. Akter, D. Fry, K. Donato and B. Piya. Drink ing Water Insecurity: Water Quality and Access in Coastal South-Western Bangladesh. I nternational Journal of Environmental Health Research, June 2016. doi:10.1080/09603123.2016.1194383
Gunda, T., L. Benneyworth, and E. Burchfield. Exploring Water Indices and Associated Parameters: A Case Study in Two South Asian Countries. Water Policy (17): 98-1 11, 2015. doi: 10.2166/wp.2014.022
Human and Social Results
- Application of multiple, mixed, and integrated social methods; Identified that the observed differences in the impact of, and response to, macro-level disasters depends on the community-level political economy and the community-level access to fresh water; Both attributes are knowable prior to a disaster; Also important but more difficult to study are community cooperation and accountable resource management.
- Observation of significantly changing livelihoods and associated migration opportunities, land use shifts, and natural resource utilization; Overall declining reliance on rice cultivation, traditional fishing, and Sundarbans mangrove resources; Increasing reliance on factory labor, seasonal day-labor migration, local aid-related day labor, cultivation of cash crops (e.g., watermelon, sunflower).
Social-oriented papers have been presented at several conferences and are being adapted for journal articles, including:
Ackerly, B., Carella, A., Cruz, J.M., and Mallick, B., “Measuring Critical Theories of Human Rights,” in Quantitative Methods in Critical and Constructivist Theory, eds. J. Samuel Barkin and Laura Sjoberg, forthcoming
Ackerly, B. “Hidden in plain sight: injustice in the context of environmental change and social inequality,” in Environment & Social Inequality, ed. Robert McLeman Springer, forthcoming
Ackerly, B., Anam, M. and Gilligan, J., “Injustice, political economies, and environmental change,” in Environment and Migration in Bangladesh – Evidence and Politics of Climate Change, eds. Bishawjit Mallick and Benjamin Etzold, AHDPH Publishing House, Dhaka, 2015
Donato, K., Carrico, A.R., Piya, B. 2014. Economic development and international migration in South Asia. Paper presented at the American Sociological Association Annual Meeting, San Francisco, CA.
Carrico, A.R., Donato, K., Sisk, B., Piya, B. 2015. International and internal migration in Bangladesh: Preliminary findings from the BEMS. Paper presented at the Ethnosurvey in Global Contexts Workshop at Vanderbilt University.
Donato, K.D., Carrico, A.R., Sisk, B., Piya, B. 2016. Different but the Same: How Legal Status Affects International Migration from Bangladesh. The Annals of the American Academy, 666(1): 203-218. doi: 10.1177/0002716216650843
Physical Environment Results
- Interannual changes in coastal land cover observed at similar water levels show a strong distinction between small amounts of erosion over large length extents and large amounts of focused deposition in specific locations.
- Detailed comparison of land-surface elevation, tidal, and sediment dynamics in poldered (embanked) and pristine landscapes; Elevation of poldered landscape is 1.0-1.5 meters below adjacent river-bank terraces and natural Sundarbans; Equates to a 2 cm/yr loss in elevation relative to sea level and almost fully a function of direct human manipulation of tidal delta plain; Landscape engineering is also linked with channel-bank migration and locally widespread embankment instability.
- Field and modeling-based investigations of geochemistry and hydrology of saline surface and groundwater sources; Surface waters are mixtures of meteoric water and salts from soil, and often exceed safe limits for salinity.
- Results showed that the maximum subsidence is occurring in a ring around Dhaka rather than in the center (Fig. 9). This is likely a combination of lithology (stiffer Madhupur clay vs Holocene) and an increase in the radius of the cone as pumping shifts away from the almost depleted aquifers. Results beyond Dhaka demonstrate that subsidence in this delta is primarily controlled by local stratigraphy, with rates varying by more than an order of magnitude depending on lithology.
- Analysis of tide gauge network time series throughout the lower delta shows consistent but variable responses to cyclone effects on water levels. Cross spectral analyses of water level time series also show consistent differences in amplitude and phase of semidiurnal and fortnightly tides related to channel network structure and geometry (Fig. 10).
Research products from the physical science team include:
Ayers J.C., George G., Fry D., Benneyworth L., Roy K., Karim M.R., Akhter F., Goodbred S.L. Sources of Salinity and Arsenic in Water in SW Bangladesh 2: Surface Water. Submitted to Geochemical Transactions.
Ayers J.C. , George G., Fry D., Benneyworth L., Roy K., Karim M.R., Akhter F., Goodbred S.L. (submitted to Applied Geochemistry ) Sources of Salinity and Arsenic in Water in SW Bangladesh 1: Groundwater. Geochemical Transactions, 17(4). doi: 10.1186/s12932-016-0036-6
Worland, S. C., and Hornberger, G. M. 2015. "Source, Transport, and Evolution of Saline Groundwater in a Shallow Holocene Aquifer on the Tidal Deltaplain of Southwest Bangladesh." Water Resources Research 5(7): 5791-5805.