The system’s course-grain functional requirements shall invariably centre on a well-structured hierarchical database, decentralised independent sub-systems and a central controller system. All sub-systems shall invariably exhibit certain characteristics as real-time performance, reliability and efficiency hence the utmost care shall be taken in procurement of supporting hardware and operating system platforms. The system’s ambient environment shall be a Linux platform for system dependability and efficiency, and seamless integration with the communication system. On the flipside, data redundancy and replication, unnecessary straining of the system controller and general system overloads shall be meticulously avoided.
Data mining in various forms shall be carried out and a centralized database management system designed. This shall facilitate ready and quick access of data to aid in trend analysis and accurate drought forecasting. The system shall be functionally devolved in data centres around the country namely synoptic agro-meteorological stations (meteorological stations concerned with data collection for agricultural research), fully automated ordinary weather and Service Specific Stations (SSS) set-up at places of specific interest like marine weather stations, major water reservoirs and hydroelectric plants. Automated Topographical Layouts shall be at hand to aid in mapping hence the use of a Geographical Information System to aid in demarcation of drought prone areas. The National Meteorological Department shall install national surveillance radar and act as a national weather watch station.
Once data obtained is analysed and a drought forecast, the system shall issue a National Drought Watch to warn of an imminent drought. Once the drought actually happens, a National Drought Alert shall be launched symbolising the onset of drought. The drought alert shall be categorised into various levels depending on drought intensity with the worst-case scenario being graded as level three.
The management system shall hence aid in provision of information on trend, monitoring and impact assessment of drought.
SYSTEM MODEL
The system’s main sub-systems shall the national grid of data collection centres, the communication system and the centralised system controller. These main sub-systems shall be multi-functional and their discrete nature shall help realize the system’s emergent properties.
FUNCTIONAL SYSTEM COMPONENTS
SENSOR COMPONENTS
This sub-system is involved with collection of data from the system’s ambient environment.
The synoptic stations shall be equipped with automated conventional operational instruments and equipment with an aim of upgrading the level of data acquisition.
All major rivers in the country shall be fitted with stream gauges at strategic places provided there is an ordinary weather station within a one-kilometre radius. At irrigation schemes, automated humidity sensors shall be installed that shall get the humidity levels at intervals of six hours. Other critical data collection centres shall be water artificial reservoirs. Automated stations shall be located at each major water reservoir. The more stations there are, the more finite and accurate the average control shall be. For monitoring of cloud cover satellite photos shall be obtained from the international weather station on a daily basis. The radar system shall be installed at the national meteorological headquarters. This radar shall provide information about precipitation and also determine wind speed.
Each station shall have a decentralised database that shall store data collected at the station level. A centralised database shall be located at the National Meteorological Department headquarters. The decentralised databases shall serve to reduce contention for the national database and hence increase efficiency.
ACTUATOR COMPONENTS
At the irrigation schemes, once the data obtained by the humidity sensors is evaluated and a drought alert issued, automated irrigator triggers shall set off sprinklers at desired intervals.
These triggers shall be activated from a computer-based system.
At the water reservoirs, every canal and water channel shall be fitted with automated valves that shall contract and reduce water flow during a drought alert. This shall result in automated water rationing. Once the drought alert passes, the valves shall automatically regulate.
The pipelines of every major water supply channel shall be fitted with leak detectors that shall be shall be put on high alert during a drought alert. Any slight leak detected shall elicit an alert at the water supply station at automatically block that water supply channel.
At the hydroelectric power stations, a reduction in water levels detected by automated gages shall prompt an alert at the turbines that shall reduce power production by a certain percentage depending on the drought alert level.
COMPUTATIONAL COMPONENTS
Most computational goals shall be achieved at hardware level by procuring up-to-date computers with support for multiple parallel processing and floating-point data processing. At the system’s level, graph plotting and extrapolation shall be achievable. Spatial interpolation has the potential to find a function that shall predict data values at un-sampled points given a set of spatial data at sampled points. This is carried out in the Data Analysis sub-system.
The National Meteorological Department shall use rainfall observations, stream stage data, and computer modelling to forecast river water levels at river forecast points during the dry season. This analysis of data shall be done by the systems’ inherent support for knowledge or intelligence based data processing.
COMMUNICATION COMPONENTS
A national communication grid shall be achieved by installation of T1 leased lines at every agro-meteorological, weather and service specific station for round the clock connectivity to Department of Meteorology headquarters. The national department shall have a fully functional Very Small Aperture Terminal (VSAT) to provide an international gateway to international weather reports. This shall aid in the uplink of data from the stations to the national centralised database. It shall also aid in inter-station communication through VOIP (Voice Over Internet Protocol), e-mail, virtual private networking and teleconferencing to enable station managers share ideas from the comfort of their offices. Every data centre shall have an Ethernet based Local Area Network linked to the national grid.
To improve coverage, Weather Radio System and Weather Radio transmitters shall be installed at every data collection centre. These shall create a national grid of transmitters to extend weather radio coverage throughout the entire country. Weather Radios shall create an emergency communication network to broadcast the forecasts to local emergency managers.
CO-ORDINATION COMPONENTS
At the data centre level, a Data Mining and Analysis sub-system shall carry out co-ordination of all system activities. The national grid shall be linked to the main Drought Early Warning and Management System at the national meteorological headquarters. This system shall be the bona-fide administrator system of the national database and co-ordinate all nation-wide activities. All communication aspects shall be controlled by the communication control system located at the national meteorological headquarters.
INTERFACE COMPONENTS
This is undoubtedly one of the most critical aspects of the system’s success. There shall be a direct link between the automated conventional operational instruments and equipment in the field and the computer terminals at the stations. The system shall provide an interface between the instruments and the data analysts at the terminal and ultimate entry of the collected data into the various databases.
