(MERI) Irrigation poverty traps in the Eastern Gangetic Plains

Agriculture is central to the livelihoods of millions of rural households across South Asia. For the majority of smallholder farmers in this region, the dominant source of irrigation water supply is groundwater.. However, large heterogeneity in access to, and use of, groundwater for irrigation also exists across the region. Low levels of groundwater irrigation are especially prevalent in the Eastern Gangetic Plains (Nepal, Bangladesh, and Eastern India). In these regions, restricted utilization of groundwater resources is associated with significantly lower cropping intensities than elsewhere in South Asia, resulting in high rates of rural poverty and decreased resilience to climate change.
Expansion of groundwater-fed irrigation in the Eastern Gangetic Plains is a key development priority for governments and international donors in South Asia. To support these efforts, research is needed to improve understanding about the factors that currently limit groundwater use in the region. For example, diesel energy costs for irrigation pumping are believed to be an important economic constraint to groundwater use for many farmers. However, to date, few studies have attempted to quantify the variability in farmers’ diesel energy costs, and there is little evidence to assess to what extent field-level differences in energy costs and reliability are explained by hydrological (e.g. aquifer structure), technical (e.g. pump efficiencies), behavioural (e.g. inefficient irrigation application), or socio-economic (e.g. water market structure) factors.
Improved understanding about the underlying drivers of groundwater pumping costs, their impacts on agricultural outcomes (e.g. crop yields), and how farmers have adapted to these constraints is critical to support development of effective technological and social interventions to increase future groundwater irrigation use in the Eastern Gangetic Plains. In particular, given the expected reliance of diesel irrigation for decades to come, a key research priority is to identify solutions to increase the cost-effectiveness of diesel pumping for irrigation, which, to date, has been neglected by researchers and policymakers. This project represents an exciting opportunity to contribute to this challenge, and support research-led solutions that could revolutionise the livelihoods of millions of smallholders.

Project Outline:
The overall aim of this project will be to develop an integrated biophysical and socio-economic understanding of the processes that shape groundwater use in the Eastern Gangetic Plains, and identify opportunities for intensifying sustainably groundwater use to improve food security and reduce rural poverty. Research will focus specifically on case studies in Nepal and/or Eastern India, both of which are areas characterized by chronically low agricultural productivity despite apparently abundant groundwater resource potential. The project will have three core components within which there will be scope for the student to tailor the research to their interests and expertise:

(1) Mapping agricultural productivity and irrigation water use: High-resolution satellite remote sensing imagery (e.g. Landsat, Sentinel, QuickBird) will be used to map field-level crop productivity and irrigation intensity in study region. Analysis will seek to assess the reliability of existing estimates of groundwater irrigation areas and the ability of satellite datasets to provide new insights about irrigation practices, and in turn identify hotspots of high/low irrigation intensity for subsequent ground-based investigation.

(2) Evaluating constraints to utilization of groundwater: For selected sites identified in (1), field surveys and semi-structured interviews, in conjunction with mechanical testing of groundwater abstraction points, will be conducted to evaluate farmers’ individual decision-making around groundwater use and investment. Given the known importance of diesel energy costs in the region, work will focus in particular on improving understanding about how and why energy costs vary between individual farmers, and what impacts these differences have on water use and cropping practices.

(3) Designing solutions to sustainably intensify groundwater irrigation: Informed by insights from (2), integrated agronomic, hydrologic, and economic models will be developed to evaluate the capacity of alternative adaptation strategies (e.g. more efficient pumps, improved irrigation scheduling) to increase the cost-effectiveness of groundwater irrigation and improve farmer livelihoods. Analysis will also seek to consider impacts of future increases in abstraction rates on aquifer sustainability, which have historically led to over-exploitation of groundwater in other parts of South Asia.

Under the guidance of the supervisory team, you will gain a wide breath of cross-disciplinary training in hydrology, remote sensing, agronomy, fieldwork methods, and socio-economic analysis. You will also have the opportunity to work directly with several local partners in Nepal (CIMMYT, Nepal Water Conservation Foundation) and India (Central Groundwater Board). These organizations will provide support to fieldwork and data collection, and are already collaborating actively with Foster and Polya as part of broader research at Manchester focused on groundwater management in South Asia.