A Probabilistic Risk Assessment of the National Economic Impacts of Regulatory Drought Management on Irrigated Agriculture

Abstract

Drought frequency and intensity is expected to increase in many regions worldwide, and water shortages could become more extreme, even in humid temperate climates. To protect the environment and secure water supplies, water abstractions for irrigation can be mandatorily reduced by environmental regulators. Such abstraction restrictions can result in economic impacts on irrigated agriculture. This study provides a novel approach for the probabilistic risk assessment of potential future economic losses in irrigated agriculture arising from the interaction of climate change and regulatory drought management, with an application to England and Wales. Hydrometeorological variability is considered within a synthetic data set of daily rainfall and river flows for a baseline period (1977–2004) and for projections for near future (2022–2049) and far future (2072–2099). The probability, magnitude, and timing of abstraction restrictions are derived by applying rainfall and river flow triggers in 129 catchments. The risk of economic losses at the catchment level is then obtained from the occurrences of abstraction restrictions combined with spatially distributed crop‐specific economic losses. Results show that restrictions will become more severe, more frequent, and longer in the future. The highest economic risks are projected where drought‐sensitive crops with a high financial value are concentrated in catchments with increasingly uncertain water supply. This research highlights the significant economic losses associated with mandatory drought restrictions experienced by the agricultural sector and supports the need for environmental regulators and irrigators to collaboratively manage scarce water resources to balance environmental and economic considerations.

Resilience of Primary Food Production to a Changing Climate: On-Farm Responses to Water-Related Risks

“…In addition, during periods of hydrological drought (extreme low river flows or groundwater levels) agricultural abstractors with 'spray irrigation' licences may be subject to emergency restrictions on the timing or volumes of water abstracted under Section 57 of the Water Resources Act [28], so-called Section 57 restrictions. This provides the government with powers to implement either partial or total bans on abstraction, both of which can have major financial consequences for agricultural food production [29,30].…”

Enhancing production and flow of freshwater ecosystem services in a managed Himalayan river system under uncertain future climate

“…irrigation, public water supply, hydropower, navigation, recreation, environmental needs) and fES (Dunford et al 2015;Holman et al 2016). The uncertainty in climate change projections cascades into spatio-temporal uncertainty in impacts (Koutroulis et al 2018;Salmoral et al 2019;Visser-Quinn et al 2019), posing major adaptation challenges for catchment management to improve or maintain the delivery of fES in the future. Process-based modelling approaches are generally preferred to assess climate change impacts and define decision-making strategies for adaptation in relation to fES (Runting et al 2017;Momblanch et al 2019a).…”

The challenges of developing an irrigation strategy for UK agriculture and horticulture in 2020: industry and research priorities

“…In addition to meeting the full crop water requirement, as no rainfall contributes to plant growth, additional water is needed to leach, or wash, salts in order to avoid salinisation of the confined root zones (Phogat et al, 2020). Not all irrigators are able to meet the theoretical demand, and actual water use is constrained by the availability and reliability of water supply (Rio et al 2018;Salmoral et al, 2019). The total national water withdrawal depends on the area of cropping (hectares and type of crop irrigated), the water applied per ha and how effectively the farmer uses it, i.e.…”

“…Irrigation abstractions are highest in East Anglia and Lincolnshire, with pockets of high demand in east and west Midlands and south-east England. Due to the high levels of agricultural and non-agricultural abstraction in these catchments that contribute to the "over-abstracted" status, there is an elevated risk of irrigation being constrained by mandatory abstraction restrictions to protect public water supply and environmental flows during dry years and droughts (Rio et al, 2018;Salmoral et al, 2019). These restrictions can take the form of either licence-specific river flow-based abstraction restrictions (so-called Hands off Flows) or the imposition of catchment-scale drought management restrictions (so called Section 57 restrictions, under the Water Resources Act, 1991).…”