Uncertainty in the Estimation of Drought Risk due to Soil-climate Interactions in Scotland

Laura Poggio*, Alessandro Gimona, Iain Brown, and Marie Castellazzi
The Macaulay Land Use Research Institute, Aberdeen, UK

Abstract: The impact of climate change on ecosystems is a global issue. As a result of the interaction between decreasing precipitation during the growth period and soil properties, thewater available for plants and crops may become a limitation factor for crops or certain forest species in some areas in Scotland. The aim of this study was to estimate the uncertainty of a model predicting drought risk in the Dee catchment in the North East of Scotland. The model focuses on the fundamental interactions between soil and climate, which are the critical drivers for determining the available water capacity. Soil available water capacity was calculated, using pedotransfer functions, with data derived from the Scottish Soil Survey Database at ca. 100 profiles. We used a variation of regression kriging to interpolate the data. The preliminary results showed that the uncertainty related to soil modelling is higher in areas with rougher morphology and complex hydrology. A Bayesian framework for uncertainty integration of soil and climate interactions is briefly presented. The evaluated overall uncertainty is useful to underpin informed policy decisions, via risk assessment.

Keywords: Gaussian simulations, spatial uncertainty, geostatistics, stochastic modelling, General Additive Model

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