Groundwater plays a critical role in supporting food security, rural livelihoods and economic development for millions of resource-poor households in South Asia. In the Western Indo- Gangetic Plains (Northwest India and Pakistan) groundwater irrigation has underpinned rapid growth in agricultural productivity over recent decades. However, in the Eastern Indo- Gangetic Plains (Nepal and Eastern India – collectively the EIGP), many farmers continue to face significant barriers to groundwater access (Saha et al., 2016), resulting in lower crop yields, shorter growing seasons, and greater vulnerability to climate change than elsewhere in South Asia (Jain et al., 2017). Expansion of groundwater-fed irrigation in the Eastern Indo- Gangetic Plains therefore is a key development priority for governments and international donors across South Asia (ADB, 2012; Mukherji et al., 2018; Park et al., 2018). However, at present, the ability of these policies to enable sustainable expansion of year-round irrigation is limited by a lack of research focused on understanding and addressing the factors currently limiting farmers’ access to, and efficient use of, available groundwater resources. This PhD project will address these critical gaps in research and policy using a combination of satellite remote sensing and household surveys to generate new empirical evidence about the processes and constraints that shape access and use of groundwater in the EIGP. The project will identify promising solutions to sustainably expand and intensify groundwater irrigation, supporting efforts to address chronic poverty and food insecurity in the region.
Research will focus specifically on three main questions, which are outlined in brief below.
Existing maps of groundwater irrigated areas covering the EIGP (e.g. Thenkbail et al., 2009; Ambika et al., 2016) are static, provide limited information about the intensity of water use (i.e. irrigation rate per hectare), and typically are based on coarse-scale imagery (e.g. MODIS satellite) that is insufficiently detailed to monitor irrigation dynamics in complex smallholder farming systems. The selected student will develop and evaluate novel approaches for mapping the spatial location and intensity of field-scale groundwater irrigation, exploiting a combination of high-resolution optical and radar earth observation imagery from Sentinel, SPOT and micro-satellite systems (Vogels et al., 2019). New mapping approaches will be trained and validated against an extensive set of existing geospatial observations of groundwater and surface water irrigation locations and management practices, which have been collected in sites across the EIGP as part of prior and ongoing projects led by partners at CIMMYT (e.g. https://csisa.org, https://ccafs.cgiar.org/big-data-analytics-climate-smart- agriculture-south-asia). Analyses will provide new insights about the current extent and distribution of groundwater irrigation in the EIGP, and identify hotspots of high/low groundwater utilisation across the region for subsequent in-depth field surveys and investigations in Parts 2 and 3 of the project.
Efforts to improve provision groundwater irrigation in the EIGP are reliant on knowledge about the factors that currently limit farmers’ access to and use of available water resources. In the EIGP, the majority of farmers use diesel-powered pumpsets to access groundwater due to low levels of rural electrification in the region. Diesel pumpsets are costly to operate, which has led to suggestions that irrigation cannot be expanded in the EIGP without transitioning to alternative pumping technologies (e.g. electric or solar) that have lower variable operation costs (Shah et al., 2006; Shah et al., 2018). However, ongoing UoM-CIMMYT research has shown that diesel-pump irrigation costs vary enormously between farmers, with potentially significant opportunities to reduce investment and operation costs of these systems (Foster et al., 2019). Building on this preliminary research, the selected student will seek to: (i) systematically identify key determinants of diesel-pump irrigation system efficiency, (ii) characterize access patterns to pump irrigation technologies as a function of geographic, socio-economic, and market factors, and (iii) evaluate impacts of heterogeneous irrigation access and investment costs on agricultural decision-making (e.g. crop choices), livelihoods and resilience to climate shocks. Analysis will be conducted through a combination of field surveys and semi-structured interviews with farmers and irrigation equipment suppliers, targeted based on insights about the spatial distribution of groundwater use in agriculture from mapping in Part 1. Work will focus on a specific case study within the EIGP of either the Nepal Terai or Eastern India, both of which offer valuable opportunities for the student to leverage and build upon existing surveys conducted by UoM and CIMMYT on pump irrigation systems in the region.
Informed by insights gained in Part 2, the selected student will subsequently design and implement an ex-ante prioritization and targeting assessment of alternative solutions for intensifying and improving productivity of groundwater irrigation in the EIGP. Analysis will focus on evaluating the suitability of alternative technological interventions implementable through existing (e.g. more efficient, lower cost diesel pumpsets) or new (e.g. renewable- based solar pumping solutions) service and equipment markets to enhance access to groundwater irrigation as a buffer against rainfall variability and climate change. Research will seek to explore how the technical, economic, and policy feasibility of alternative technological solutions varies between farmers of different resource endowments and risk profiles. Analysis will consider explicitly key socio-economic constraints to irrigation and agricultural practices in the EIGP, including high levels of land fragmentation, declining rural labour availability, limited purchasing capacity, and high levels of risk aversion among smallholders. Research will thus identify optimal short- and long-term technological solutions and provide a suite of well-developed policy recommendations for intensifying and expanding the sustainable use of groundwater irrigation, while also providing guidance on promising business models to enable uptake at scale by farmers more broadly across the EIGP.
Dr. Tim Foster and Dr Johan Oldekop at the University of Manchester, in collaboration with Dr. Timothy Krupnik at the International Maize and Wheat Improvement Centre (CIMMYT), will supervise the project. You will join a large and dynamic international group of research students and staff at Manchester (www.fosterlab.weebly.com) and CIMMYT (www.cimmyt.org/people/timothy-j-krupnik/; http://www.timothyjkrupnik.net/) working to improve the productivity and sustainability of farming systems across South Asia. Under the guidance of the supervisory team, you will benefit from high-quality cross-disciplinary training in remote sensing, agronomy, fieldwork methods, and socio-economic analysis, along with professional research and teaching skills development through the GOLDEN PhD programme. You will have access to a wide range of datasets and models required to support your research, along with generous funding to conduct fieldwork and extend research visits in South Asia as part of the project. Finally, through the supervisory team you will be actively supported to collaborate and engage with major international agricultural research centers in the South Asian region, along with regional and international agencies and institutions engaged in agricultural and irrigation development.