Agroclimatic characterization of the Central and West Asia and North Africa (CWANA) region - the mandate area of ICARDA (Fig.1) - is of paramount importance to assess the occurrence of abiotic stresses, particularly extremes of temperature, heat and drought. In view of the high spatial and temporal variability of climatic conditions in this region, both of precipitation and temperature, a risk assessment of climatic stresses in this region involves a quantification of stress probabilities. However, the low density of meteorological stations in the CWANA region, the high volume and purchase cost of meteorological data, and many gaps in data records do not allow these stresses to be quantified in most locations in the region.
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Figure 1. CWANA region (grey
with hillshading); Syria in thick black line
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To address this problem a joint study was undertaken between the Plant Stress and Water Conservation Laboratory of the Agricultural Research Service (ARS) of USDA in Lubbock, Texas, and ICARDA's GIS Unit (for more information please visit: http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=172629). The objective was to develop a GIS-application (the 'ICARDA Agro-Climate Tool'), allowing a user to select any agricultural location inside the ICARDA mandate region through a simple Windows user interface and obtain a set of relevant views on the climatic stresses at that location for the selected crop, growing season and soil type. The outputs of the Tool are estimates of means and probabilities of exceeding user-defined thresholds for temperature and precipitation on daily basis, or for time periods that can be defined by users. The results can be viewed as graphs or exported as data files for use in other software applications (Fig. 2).
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Figure 2. The Tool's 'dashboard'
interface
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The Tool's engine is a 'weather generator', which is actually a software module that generates artificial series of climatic data through a process of stochastic simulation. In order to operate, the weather generator had to be parameterized for different parts of CWANA by using real climatic data series. For the development of the Tool several public domain databases were used. Precipitation, minimum and maximum temperature data for 649 stations were obtained for the period 1977-1991 from two climatic data archives in the public domain, the Global Daily Summary Data (GLDS) and the Global Daily Climatology Network (GDCN). Also a crop database containing information for irrigation has been added, as well as the GTOPO30 Digital Elevation Model, and simplified maps of country boundaries, population centers, agricultural areas, roads and station locations. All these databases are 'embedded' inside the application.
The weather generator used is GEM6, developed by the USDA-ARS (http://www.eightnine.org/USClimateGEM.htm) . The feasibility of using the synthetic climatic data produced by the weather generator software, instead of real climatic data, stands or falls with its ability to reproduce realistic estimates of the real climatic parameters. A validation was undertaken by comparing the statistics of the generated data with those of the real data, which showed satisfactory agreement (for more details is referred to the Technical description which, together with the software, can be downloaded from this site. The Tool currently has some limitations, notably the short time series used to parameterize the weather generator, but a newer version is in the make that will use a longer and more up-to-date time series.
The main benefit of the Tool is that the use of synthetic climatic data allows to a major extent to overcome the limited climatic data available for ICARDA's mandate region. The potential applications of the Tool are in the area of crop breeding, targeting existing or new varieties of ICARDA commodity crops, with particular tolerances or sensitivities to various climatic stresses, to environments where these varieties have not been tested. The Tool's powerful features make it very useful for the quantification of climatic variability and major climatic stresses, and by extension, for the characterization of stress tolerance of genetic resources found at particular accession sites. It can also benefit water management specialists, who can use it to assess potential impact of rainfall and temperature variability on crop water and irrigation requirements, under current conditions or, after upgrading, under different climate change scenarios.
Click here to download the tool (112 MB).
Supporting documents:
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README file |
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The Tool in 10 steps |
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Using GIS-embedded weather generators for characterizing climatic stresses in the CWANA region (presentation) |
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Technical Description |
For more information, please contact Dr Eddy De Pauw
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© 2008 International Center for Agricultural Research in the Dry Areas (ICARDA). See copyright and disclaimer information
© 2008 International Center for Agricultural Research in the Dry Areas (ICARDA). See copyright and disclaimer information