Context and objectives
Soil salinity is a problem of irrigated soils in arid and semi-arid climate zones. In alluvial planes, soil salinity often occurs in connection with waterlogging. About one third of the agricultural lands in Egypt are affected by these two phenomena. Salinity is still increasing in many irrigated fields because of lack of adequate drainage systems. The Egyptian government decided to start solving this specific problem in relation with water management and agricultural development in the province of Ismailia.
The task of the IDSC in Cairo is to gather and distribute information for planning purposes and as a tool for decision making for several institutions (such as the provincial government, the national environment agency, local users and other administrations). In 1994, up-to-date and synthetic data regarding salinisation and waterlogging were not available in the information system of the IDSC. There was also a need for a monitoring system and a computer simulation model for prediction of future risks (in terms of space and time). It will a.o. allow an evaluation of the impact of implementing infrastructure projects in agricultural lands.
The expertise in the use of remote sensing in the domain of salinisation, available at the Belgian Universities, was transferred to Egyptian user partners through a pilot project.
Expected scientific results
- Up-to-date soil salinity and waterlogging map, 1:50.000, in digital and analogue format;
- Operational computer model for risk simulation of salinity and waterlogging;
- Methodology/procedure for model construction, also applicable in other areas in Egypt.
LANDSAT TM satellite images are a good choice for mapping soil salinity because of the high spectral resolution of the images (a.o. the thermal infrared band allows distinction between soluble and non-soluble salts in the soil). Spring is the most suitable acquisition period.
The computer model has been integrated successfully in the IDSC's GIS. Decision makers in the domain of public works, agriculture, water management and the environment in Egypt show great interest in the model in view of a sustainable development of their country which is characterised by high population pressure and limited agricultural land resources. The risk simulation model will probably by applied to evaluate the long-term impact of planned projects for desert reclamation.