SAMIS stands for Sudan AgroMeteorological Information System. SAMIS is an operational system to produce agro-meteorological information from meteorological ground station and satellite data (METEOSAT and NOAA). SAMIS is operated at the Sudan Meteorological Authority (SMA) and at the Sudan Early Warning Unit of the Humanitarian Aid Commission (SEWS) and outputs a set of information products relevant to a range of user institutions involved in the management of agricultural, hydrological and environmental resources. The season of 2003 is its first operational season.
SAMIS was designed and produced by the TAMSAT group at the Dept Meteorology of the University of Reading in collaboration with the Sudan Meteorological Authority with funding from the World Food Program (Sudan) Vulnerability Assessment and Mapping Unit.
WFP funded the installation of technical capacity and provision of training at SEWS and SMA, enabling local production of satellite based rainfall and vegetation information for distribution to a wide range of national and international users. The IGAD Remote Sensing Project is providing the NOAA and METEOSAT data reception, though currently the system uses input data provided by the TAMSAT Group.
For information on the technical details of the operational system please contact Dr. Rogério Bonifácio (TAMSAT group, Dept of Meteorology, Univ of Reading, UK) :
SAMIS is composed by an organised set of automated software procedures that generate a number of information products from meteorological station and satellite data. Each software procedure implements a given methodology and may use a number of auxiliary data (climatology) and settings (calibration maps, region and format specifications).
SAMIS interface for a dekadal processing task (for daily, monthly and seasonal tasks are not shown). Tasks to be carried out are checked. Any number of time steps can be run (all dekads of a season, all dekads of a given month for several years, etc,)
This set of software procedures is integrated into a user-configurable graphical user interface which allows non-experts to produce the required routine outputs. The graphical user interface allows the production of outputs for individual time steps (day, dekad, month) or bulk production of data for multiple time steps (e.g. all the outputs for a whole season).
SAMIS is also open and configurable by its operators, so that it can meet the changing needs of its users and the evolution of data sources and algorithms. Its outputs can be visualised/analysed in low cost IP/GIS software, such as IDRISI and WinDisp.
The physical components of SAMIS are :
· The Sudanese national network of meteorological synoptic stations. These 28 stations provide daily gauge rainfall, maximum and minimum temperature, wet bulb temperature, sunshine hours and wind speed. This data is used in the preparation of 10 day rainfall estimates (gauge rainfall) and 10 day Potential EvapoTranspiration (PET) values.
· A data link for reception of METEOSAT satellite TIR (thermal infrared data) pre-processed into CCD (Cold Cloud Duration) an indicator of the duration of rain bearing convective storm clouds which is used to provide estimates of rainfall on a ten daily basis.
· A NOAA HRPT receiver which receives all 5 NOAA channels and outputs the data calibrated into reflectances (channels 1 and 2) and brightness temperatures (channels 3 to 5) on a lat-long grid. Imagery from this satellite is used for both vegetation monitoring (day time images) and large scale flooded area monitoring (night time thermal images).
· Alternative data for vegetation monitoring is also downloaded from the Africa Data Dissemination Service (ADDS).
The input data streams being used in the SAMIS version currently installed at SMA are as follows :
· METEOSAT TIR data processed into daily and 10 daily Cold Cloud Duration (CCD) – This data stream should soon be available at the Sudan Meteorological Authority (SMA) HQ in Khartoum. The TAMSAT Group will provide the CCD data until such availability is established.
· Calibration maps – these allow the conversion of daily and 10 daily CCD data into daily rainfall probability and 10 day rainfall amounts.
· Climatological average 10 day rainfall amounts – derived from a combination of CCD and rain gauge 30 year average data
· Climatological average frequency of rainfall occurrence – derived from a combination of CCD and rain gauge 30 year average data
· Daily and 10 daily observation data from the Sudanese synoptic station network – This data originates from the routine activities of the SMA. The parameters of relevance are precipitation and all those required to produce PET (Potential EvapoTranspiration).
Other input data streams are not yet available or integrated in the operations but are expected to be available soon :
· NOAA-AVHRR data – daily sets of NOAA/AVHRR channel images (reflectance and brightness temperature). This data stream will originate from a receiver installed at SMA by the IGAD Remote Sensing project and currently waiting operationalisation.
· SPOT NDVI data – 10 day NDVI maximum value composites provided by the IGAD regional data dissemination hub (expected under routine provision soon).
SAMIS outputs the following information products (detailed information on the product's background can be found here):
· Rainfall Occurrence (daily)
· Dekadal Rainfall (10 daily)
· Dekadal Rainfall Anomaly (10 daily)
· Cumulative Rainfall (10 daily)
· Cumulative Rainfall Anomaly (10 daily)
· Dekadal Number of Rain Days (10 daily)
· Length of Dry Spell (number of consecutive dry days till present) (10 daily)
· Monthly Rainfall (monthly)
· Monthly Rainfall Anomaly (monthly)
· Monthly Number of Rain Days (monthly)
· Vegetation Index (10 daily) and departure from average
· Qualitative monitoring of large scale seasonal flooding, e.g. Sudd (10 daily)
· Agro-Met indicators (Precip/PET ratios, dates of growing season onset)
· WRSI (FAO Index)
The above parameters are produced for an area covering the Sudanese territory. Coverage outside Sudan for the rainfall parameters should not be used.
The Sudanese Meteorological Authority produces a dekadal bulletin which is disseminated by e-mail
(as a MSWord document) to a range of users. The same Bulletin is also offered in a web version within this site - see
Current Bulletin.