An enhanced version of the D-Risk decision support webtool for multi-scale management of water abstraction and drought risks in irrigated agriculture

Due to it having the lowest priority for water allocation during drought events and consequent agronomic economic impacts of abstraction restrictions, UK irrigated agriculture has been identified as a key business sector ‘at risk’. An enhanced version D-Risk webtool developed help agricultural stakeholders catchment managers evaluate joint multi-scale risks restrictions (voluntary mandatory) insufficient irrigation volumes events. The uses annual maximum potential soil moisture deficit agroclimate index calculate monthly volumetric demand selected crop mix, available capacity location. Simulated river flows are used identify days not under restrictions. Annual probability distributions licence utilisation (headroom) derived from time-step balance model that calculates whether farm in each month can be met, taking account flow-based daily licensed limits, licenced period(s) any on-farm reservoir storage. tool provides more holistic understanding risk on individual scales supports improved collaborative decision-making regarding future sharing, trading investment reduce vulnerability regulatory change.