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Urban & Housing

Change Detection
Riyadh City  

Urban planning and utility management require constant monitoring of the urban area spread with time. This  enables the service providers to expand their services in line with the urban expansion pattern. 

 

There is an exponential growth in the urbanization of Riyadh city over the years. To monitor the trend  of urban growth over the years, medium resolution images from LANDSAT & SENTINEL 2 are analyzed to estimate the magnitude of the urban growth. The urban built-up area of Riyadh has increased from about 473 Sq.Km in the year 2000 to about 1283 Sq Kms in the year 2020. The expansion trends show that the urbanization is more towards North  & SW directions of Riyadh City.

 

  Marking the changes  at a better scale & at localized levels require high resolution images. Individual building level changes can be seen in these images. The High-resolution images  show the urban area changes in one of the quarters, North of Riyadh. Digital land base maps are created from these images. 

 
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Agriculture Mapping

Central Pivot Agriculture
Al Jouf, KSA                              November 2019

Al Jouf region in Saudi Arabia is one of the most important agriculture growing areas in the Kingdom. The area under agriculture has increased significantly in the last 2 decades. The crops are grown mostly in central pivot type farms. The source of the irrigation is  groundwater resources. Type of crops grown in the area include Fodde crops, Wheat, Barley, Vegetables and fruits. Apart from these farms large farms grow olives and dated. Al Jouf has one of the largest olive farms in the world. 

 

Crop mapping & monitoring is done over  all the agricultural areas in KSA for Winter and summer seasons. Image classification, using SPOT 6 & 7 satellite images  and the field collected sample data, is done to generate the crop theme map for each season. Crop types and the area covered by them is estimated and a detailed crop statistics geodatabase is created to be integrated with other datasets. 

 
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Stream Network Analysis

Drainage Basin Analysis
Jizan, KSA  

Drainage basin is an area where the precipitation water gets collected and flows towards the outlet through a network of streams. Drainage basin is also called as the catchment area. 

  

Drainage basin is delineated  from high resolution Digital Elevation Models (DEM). Based on the precipitation data & other parameters, the total volume of the surface runoff is estimated. Stream networks extracted from the elevation models are analyzed to delineate watersheds based on the pre-selected pour  points. Areas vulnerable to flooding in the event of intense rainfall can be identified and the data is made available to the decision makers for appropriate planning and action.

 

Detailed analysis of the basin, streams and the topography is used to identify suitable locations for construction of small dams, weirs and other structures.

 
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Mining monitoring

Mine monitoring
Al Yamamah Mine; Riyadh KSA  

High resolution stereo images are indispensable in 3D modeling. Detailed terrain mapping can be done by processing the stereo images. Digital Terrain Models (DTM) & Digital Surface Models (DSM) can be accurately derived. Detailed building heights and the height of other constructed features on the earth’s surface can be measured accurately. 

  In Mining industry, the stereo images play an important role. They can be utilized to create 3D models of the mines, pits, excavated areas. Using the accurate 3D models the total volume of the excavated material from a mine can be estimated. The mining activity can be monitored by collecting stereo images over the mines at specific intervals. Similarly, the volume of the material in mounds, hills etc. can be estimated. 

 

Volume of the excavated material from the present mine is estimated to be 45.89 Million cubic meters. The volume is estimated below a reference level of 576m (AMSL) The deepest point in the mine is  about 55 meters below the reference level.

 
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Forest Fire monitoring

Forest fire monitoring
Al  Azizah, Asir region KSA

Fire occurred in the forests of Al Azizah mountain near Abha in Asir region  on 26th October 2020. About 3.2 million Sq. meters of area was affected by the fire. Large number of perennial trees were destroyed in the fire. The civil Defense teams  have effectively controlled the spread of the fire and thereby saving other areas from fire. Satellite images are used to determine  forest areas which are affected by the fires. SENTINEL 2 satellite images are used to analyze the  burnt area. Pre and post fire images were  used for this analysis.  Near Infrared & Shortwave Infrared bans were used to estimate the Normalized Burn Ratio (NBR) for pre and post images. The burnt area was extracted from the ratio images. 

Burn severity can also be estimated to identify zones which are severely burnt. Continuous monitoring of the burnt areas can be done to monitor the regrowth in the areas.

 
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Viewshed Analysis

Viewshed Analysis
Ar Rayth , Asir region KSA

The viewshed analysis tools are useful when you want to know how visible objects might be—for example, from which locations on the landscape will the water towers be visible if they are placed in a particular location, or what will the view be from a road?

In the example 1 , the viewshed from an observation tower is delineated. The elevation raster displays the height of the land (lighter shades represent higher elevations), and the observation tower is marked as a yellow point. The height of the observation tower can be specified in the analysis. Cells in light blue are visible from the observation tower, while cells in dark blue are are not.

Observer Height AGL  : 30 m

Observation Range  : 3ooo m

Field of View (FOV)  : 360 degrees

Elevation profiles and Line of sight (LOS) generated between points A & B 

Red areas : Hidden, Green areas : Visible

 
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Land use/Landcover

Landuse/Landcover
Riyadh, KSA  

Riyadh city, the capital of Kingdom of Saudi Arabia, is one of the fastest growing cities in the Middle east. The population of Riyadh has increased from 3.6 million in the year 2000 to about 7.38 million in the year 2021 (worldpopulationreview.com).  Riyadh city has seen a rapid urbanization in the past few years. Many developmental projects and residential areas are coming up, thereby expanding the urban sprawl. Monitoring  the magnitude & direction of growth of urbanization is critical in sustainable development of cities. 

 

  Landsat 8 image with 15 meters spatial resolution is used to delineate the urban built-up area of Riyadh city.  The image shows the present-day  land use pattern of the  city. The thematic map shows the urban built-up area , vegetation cover (includes urban vegetation and  date farms along the Wadi Hanifa). The industrial areas in the city are shown in shades of orange color.