To have the ability to predict, by modelling, the effects of a
given climate change scenario on the crop suitability of areas of
land based on the known soil pattern, the properties of these
soils, and the growth requirements of strategic crops (wheat,
maize, grass, sunflower, potatoes, sugar beet).
An existing agroclimatic soil-crop suitability model is being
further developed in terms of improvements in input, and to
include a wider range of crops, soil types and climate factors
than are considered at present.
In the course of this exercise,
the following steps are being followed: identification of
regional crop requirements (including construction of a
phenological database); development of extra modelling routines
for the assessment of erosion risk, irrigation requirement, water
quality/salinization risk, and baseline soil fertility criteria.
An improved water-balance sub- model is also being produced with
especial ability to reflect soil and crop behaviour in drier
environments, to deal with cracking soils and bypass flow, and to
deal with frozen ground and snowmelt. The improved model and
associated databases are being integrated into an expert
land--evaluation system. An important aspect of the modelling is
the way it will deal with spatial aspects of the data.
The policy requirements of the model are to make predictions for
regions i.e. large areas from several hundred square kilometres
to several thousand square kilometres in extent. Experimental
sites form the basis for extrapolation to the regions defined
above, where fewer data are available. Robust pedo-transfer
functions will be developed to enable the model to make use of
simple soil survey data, so as to calculate acceptable values for
soil hydrological properties which are either difficult or
expensive to measure, or are rarely measured.
At the regional or national scale (defined as Level I) this part
of the model is simple in order to accommodate large amounts of
input data describing large areas of land (numerous
crop-soil-climate combinations). Conversely, a more complex form
of the hydrological model (defined as Level II) has been
developed for test sites (small areas of land), where large
amounts of very detailed data are available e.g. daily or hourly
meteorological data; long term runs of experimental data. The
complex modelling is being used as the validation step for the
simpler modelling. The system of land evaluation is based on the
concept of acceptable regional productivity for specific areas.
This allows variation in acceptable yield to take into account
local cultivars, cultivation practices, economic returns and so
on. Thus each strategic crop can be assessed within its regional
climate-soil framework, without the whole model and evaluation
exercise being distorted by the yield targets achieved in the
highest yielding parts of the Community.
The complete system is designed with a user-friendly interface on
a PC, and will lend itself to applications through widely-used
GIS data formats. Demonstrations of regional applications of the
model will be done for areas in southern England,
Languedoc-Roussillon (F) and Andalucia (ES), Poland, Hungary and
Funding SchemeCSC - Cost-sharing contracts
CB2 2LF Cambridge