ملامح التغير في خريطة استخدامات الأرض بمدينة نجران خلال الفترة 1975-2016م باستخدام تقنيات الاستشعار عن بعد

الملخص EN

This study focused on the use of remote sensing technology in the surveillance and detection which occurred on the land use map on Najran City in the era between 1975 and 2016 A.C through classifying the visual space wave LandSat-2 MSS for the year 1975 A.C, and visual space LandSat-5 TM for the year 1990 A.C, and visual space LandSat-8 OLI/TIRS for the year 2016.

The remote sensing technologies have showed high efficiency in monitoring and tracking land use for cities over long periods of time.

The importance of remote sensing is also increased in Najran City after witnessing the rapid variations in land use where the city lost 5837 hectares of agricultural areas in less than 25 year between 1990 and 2016 A.C at a decreasing rate of 2.9% and average of 243 hectares per year.

The city cannot compensate for this loss over the 40 years from 1975 to 2016 A.C.

The continuous loss of agricultural lands at this rate will make it get disappear in less than 24 years.

Najran City also lost more than 1984 hectares of the natural wadi area which is equal to 2118 hectares at an average decreasing yearly amount of 43.5 hectares corresponding to 6.8%.

The change between 1975 and 2016 is estimated by 93.7%.

If this decrease in the wadi area is persistent, then all features of the wadi will be faded.

This situation will permit flooding to happen in Najran City because the wadi channel itself convey the flows of the wadis and protect the city from floods.

Perhaps the most important feature of the change in the land use is the rapid urban development where the increase in development reached 73.2 times as much area in 1975 A.C.

The urban increase 3981.7 hectares distributed over 40 years at an annual growth rate 11.9% and average annual increase of 99.5 hectares along the period.

The space area had dropped in Najran City during 1975 and 2014 at a rate of 0.2%.

The area decreased is 3722 hectares and the rate of change is 7.4%.

The conclusion of this study presents the recommendations and solutions for the management of the urban environment in Najran City and addresses the clear deterioration in the map of land use in the city.