إعادة توقيع القنوات المائية القديمة الخرز في سهل الخرج باستخدام دمج البيانات المكانية

الملخص EN

Objective: the study seeks reallocate old artificial canals in Al-Kharj area using different spatial data.

The study also attempts to apply the best technical image merging method between remote sensing data and ols maps to delineate the old tracks of these artificial canals.

Methods: all image merging methods provided by Erdas software were applied to select the best method to allocate the canals and show their relation to the roads and residential plans; these merging methods include IHS, Brovey and multiplication methods.

Also, ArcGis software has been used to create a geographical database for the region to maps the ols tracks of the canals on the current spatial data of Al-Kharj city.

Results: the study found that the multiplicative method was the best method among the three investigated image merging methods for mapping the canals and reallocating their adequate tracks on the remote sensing data.

Therefore, the output merged image with IKONOS images showed both the old canals and the current situation of the Al-Kharj plain.

Conclusion: the study concluded that Al-Kharj old canals can be divided into two parts: The first part included prehistoric subsurface canals which had been restored during the Islamic history, while the second part included open canals dating back to ancient times and which gave been expanded recently due the increase of irrigation by pumping water from artesian wells and deep aquifers.

While most of the canals have vanished, some are still facing the threat of elimination by active urban developments.

Geomorphology plays the largest role in the spatial distributions of the old canals of the Al-Kharj plain, as the sources are located at the bottom of the mountain slopes dominated by karst rocks surrounding the palin, while the canals continue in a track parallel to the valleys that cross the plain towards the east.