DelegatePack_DroughtConference_20-21March2019

Speakers
Day 2: Plenary – The Pichette Auditorium
Kerstin Stahl University of Freiburg
Customising drought indices to improve drought impact monitoring and prediction
Drought risk management, including monitoring and early warning, still relies primarily on drought indicators selected
or combined from hydro-meteorological variables, such as precipitation, and in fewer cases on modelled soil moisture,
observed or modelled streamflow, or remotely sensed vegetation health. To guide the selection and give more
meaning for drought management decisions, a number of studies have investigated empirically the linkage between
these indices and records of drought impact occurrence. These studies have been inspired by the damage function
approach employed in risk assessments of other natural hazards. Based on studies in Europe and the USA this
contribution illustrates challenges and potentials of validating the suitability of indices with impact information,
customizing thresholds for warnings and finding impact-indicator link functions that may be suitable for a prediction of
the probability of impact occurrence. Impact information was derived from large archives of text-based, coded impact
reports, such as the European Drought Impact report Inventory and the US Drought Impact Reporter and links and
link functions were analysed at various spatial scales for various subsets of impact types and drought events. The
identified challenges include the rapid decrease of data when subsetting for specific impact sectors or smaller spatial
areas, the choice of the link model, and a variety of potential dynamic changes to the underlying conditions between
and even during drought events. Based on the assessment, recommendations for a successful and applicable link model
include in particular a careful pre-processing of index and impact data and more systematic impact data collection in
the future.
Mike Morecroft Natural England
Drought impacts on the natural environment and lessons for climate change adaptation
The Earth’s climate has changed as a result of greenhouse gas emissions and will continue to change, even if emissions
are successfully and quickly reduced. Adaptation to climate change is therefore essential and an increasingly
recognised priority in environmental management and policy. An increased risk of drought, especially during hot, dry
summers is one of the key aspects of climate change that we need to adapt to in the UK. Over the last few decades
there have been a number of periods of drought and we can look at how these affected the natural environment to
get a better understanding of the threats we face. This shows that drought affects a wide range of ecosystems and
species. Amongst species some are adversely affected but others can benefit. The risks are greatest when a dry
summer follows a dry winter as soil water and flow in rivers is already low at the start of the summer. The Impacts
are however modified by soil type, catchment and management. The indirect effects of drought, such as increased
abstraction and, as graphically shown in the summer of 2018, increased wildfire risk, can be just as important at the
drought itself. Looking to the future, there are a range of potential adaptation measures including: wetland
restoration, reducing abstraction, better control of water levels in protected sites and diversification of tree species to
decrease risks to woodland. Climate change adaptation can’t be a stand-alone activity, it needs to be thoroughly
integrated into the way organisations operate and I will illustrate this from our work in Natural England.
Ian Holman Cranfield University
Taking lessons from the 2018 drought forward into increased drought resilience in the agricultural
sector
The 2018 drought had widespread and varied consequences for all parts of the agricultural sector in the UK. This
presentation looking back at 2018 will cover four main components. Firstly, the unusual meteorological characteristics
of 2018 that proved so challenging for UK agriculture will be described. Secondly, a quantitative analysis of the wide
range of impacts of the 2018 drought on the livestock, rainfed and irrigated agricultural systems will be described,
based on reporting within specialist sector publications, identifying both negative and positive impacts of the drought.
Thirdly, the range of short-term coping and longer term strategic reported responses to the drought will be
described. Finally, building on the preceding analyses and recent interviews with farmers, the presentation will reflect
on three lessons from the 2018 drought and how they might be taken forward to support increased drought resilience
in the agricultural sector: (1) the need for improved strategic planning at all levels and scales, from farm to catchment
to supply chain; (2) the need to enable best use of licenced water during drought through improved forecasting,
monitoring and evidence-based decision making; and (3) the need to enable the continuing de-synchronisation of
irrigation demand and irrigation abstraction through investment in winter storage.