An actor-oriented integrated assessment of groundwater irrigation within southeast Cambodia's sustainable development context

Abstract

Sustainable development and integrated water resources management (IWRM) have been embraced globally yet shown limited effectiveness in improving social and environmental outcomes. Impacts on communities and the environment persist, a major one being ongoing degradation of groundwater systems that are valuable for poverty reduction but vulnerable to exploitation. A key challenge for water managers is to motivate a shift from a development mindset to resource management. Barriers include contextual complexity and uncertainty, often neglected by water-centric and technocratic analytical approaches. Deeper technical, social, and organizational limitations to progress with IWRM do not receive enough attention. Finding solutions requires expanding analytical boundaries to better-capture human-nature linkages and the social context of groundwater assessments. Critical to this is recognising the role of both factual knowledge and subjective judgements in scoping and problem framing. Integrated assessment and modelling (IAM) offers a rigorous approach to complex IWRM problems. However, IAM typically relies on a starting stakeholder consensus in problem framing to reduce, rather than propagate, the complexity and uncertainty associated with human dimensions. This thesis derives practical insights for better-including the human dimensions of IAM by approaching boundary judgements from an actor-oriented perspective that embraces a diversity of stakeholder mental models. Concepts from rural sociology and systems thinking are used to integrate consideration to human agency, unequal power dynamics, and differentiated stakeholder outcomes. Exploratory analysis is harnessed to test multiple conceptualisations, characterise influential factors, and identify robust pathways forward. The case study of southeast Cambodia is adopted to ground insights within an economy characterised by growing inequalities and quiet tension between the use of groundwater for irrigation and for household water supply. Three contributions emerge. The first is a set of three principles, and an actor-oriented methodology, proposed to highlight whose perspectives, and what broader contextual factors, inform IAM boundary judgements. Cognitive mapping and boundary critique of sectoral practitioners and smallholder farmers inform the design of exploratory integrated models using a groundwater model and Bayesian Networks. Scenario outputs then challenge those stakeholder perceptions hindering groundwater management. Lessons learnt suggest the following benefits: maximum use of available knowledge in a low-resource context; problem framing guidance when a starting consensus may not be feasible or advisable; and parsimony by structuring exploratory analysis at different scales according to stakeholder perspective. A second contribution relates to empirical findings about the stakeholder perceptions hindering better groundwater management outcomes. Water sector practitioners held central beliefs that groundwater is an undesirable source of irrigation, and that drawdown will likely be self-limiting given the low value of irrigated rice crops. They envisioned that rural transition and associated policy will be sufficient to avoid groundwater depletion and promote sustainable development. In light of national strategic indicators, such perceptions were found to risk encouraging perverse management incentives. A third contribution is the deriving of knowledge about the dynamics of southeast Cambodia's groundwater socio-ecological system. Findings showed that farmers pump groundwater to irrigate rice as one of few local income opportunities, but that resulting increases in potential profit and debt distributions risk worsening socioeconomic inequality. Finally, three themes are identified to support Cambodia's IWRM: expand sector objectives; centre a customer service approach; and manage for robustness of smallholder livelihoods in pursuit of sustainable development. Show more