Abstract
Drought has wide ranging impacts on all sectors. Despite much effort to identify the best drought indicator to represents the occurrence of drought impacts in a particular sector, there is still no consensus among the scientific community on this. Using a more detailed and extensive impact dataset than in previous studies, this paper assesses the regional relationship between drought impacts occurrence in British agriculture and two of the most commonly used drought indices (SPI and SPEI). The largest qualitative dataset on reported drought impacts on British agriculture for the period 1975–2012 spanning all major recent droughts was collated. Logistic regression using generalised additive models was applied to investigate the association between drought indices and reported impacts at the regional level. Results show that SPEI calculated for the preceding six months is the best indicator to predict the probability of drought impacts on agriculture in the UK, although the variation in the response to SPEI6 differed between regions. However, this variation appears to result both from the method by which SPEI is derived, which means that similar values of the index equate to different soil moisture conditions in wet and dry regions, and from the variation in agriculture between regions. The study shows that SPEI alone has limited value as an indicator of agricultural droughts in heterogeneous areas and that such results cannot be usefully extrapolated between regions. However, given the drought sensitivity of agriculture, the integration of regional predictions within drought monitoring and forecasting would help to reduce the large on-farm economic damage of drought and increase the sector's resilience to future drought.
Highlights
In recent decades the severity and frequency of extreme climatic events, including droughts, have increased significantly, causing severe damage, casualties and injuries around the world (FAO, 2008; Giddens, 2011)
This paper aims to assess the probability of drought impacts on agriculture for each region of the United Kingdom (UK) using regional drought indices based on meteorological data, so Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) were chosen as representative indices that are derived from readilyavailable data
This contrasts with Bachmair et al (2016), who found that SPI and SPEI were very similar in terms of the strength of correlation in the UK
Summary
In recent decades the severity and frequency of extreme climatic events, including droughts, have increased significantly, causing severe damage, casualties and injuries around the world (FAO, 2008; Giddens, 2011). Climate change is expected to contribute to this increasing trend, posing greater risks to society, the environment and those sectors dependant on precipitation and water resources (IPCC, 2014). Drought differs from other natural disasters in the slowness of onset and its usual lengthy duration (European Commission, 2007a). Its effects accumulate slowly over time, so it is difficult to determine the onset, duration and termination of a drought event (European Commission, 2007b; Parry et al, 2016; Wilhite, 2007). The agricultural sector is sensitive to drought and water scarcity (Wilhite et al, 2014) as it is directly dependent on precipitation and evapotranspiration. Drought impacts do not depend only on the severity of the hazard, and on the sensitivity of a sector or activity. As agriculture varies spatially, the vulnerability to the same drought is different, and so are the associated impacts
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
