Characterization and Mapping Land Degradation Hotspots in the Terrestrial Ecosystem of Kuwait

Land degradation processes prevail in about 50.6 % of the terrestrial ecosystem of Kuwait. This ecosystem which covers about 15,000 km2 (about 85 % of Kuwait) is dotted by a high number of land degradation hotspots (LDH). A hot spot is a severely degraded area, where land degradation indicators are observable. The main objectives of this study are to detect land degradation hotspots and to quantify the impact of land uses on the natural vegetation and soil types. Detection of land degradation hot spots is a significant prerequisite for Land degradation control. The land degradation hotspots were delineated and characterized using Geographic Information System (ArcGIS S/W 10.5) and satellite image (Landsat 8 of September 2017). A ground truth activity followed the Landsat analyses. The approach of detection and mapping land degradation hotspots is simple and applicable in Kuwait and the surrounding countries. The results of the study showed 58 hotspots with a total area of about 7590.3 Km2 (50.6 % of the terrestrial environment). The study reveals a significant variation in the areas, land use and indicators of land degradation of the hotspots. The areas range from about 2000 km2 to 1.2 km2. In all of the hot spots, the soils, vegetation cover and micro land features are highly degraded due to destructive land use types including overgrazing, offroad vehicles, camping and recreation, and soil mining. The total length of off-road vehicles is around 14,774.67 Km ( 0.98 Km/ Km2 ) and the percentage of degraded vegetation and disturbed soil was 48.7% and 47% respectively. abstract


Introduction
In Kuwait, the lack of quantitative information and georeferenced data on the extent of degraded lands represents one of the significant challenges facing the development of an action plan for land degradation control. Application of remote sensing and GIS, besides ground truth and intensive field surveys, is a practical and cost-effective tool for mapping and characterization of land degradation. In the present study, the term land degradation hotspots (LDH) is used to characterize areas of different sizes, where the vegetation cover and the soil types are severely degraded. Degradation was caused by excessive human pressure under drought conditions. The past land uses for the majority of the hotspots were rangeland grazing and seasonal recreation activities. The vegetation map [1] indicates that the lands of the hot spots were covered with perennial vegetation. The present study indicates that this perennial vegetation is totally disappeared, and the soils are highly degraded due to destructive land use types.
The most common soil degradation processes are soil losses (by both wind and water), soil compaction and sealing and soil mining. As indicated in a huge number of publications, e.g., Omar et al. [1] Khalaf et al. [3] and Misak et al. [4], one of the main consequences of drought is the deterioration of vegetation cover. Land degradation processes prevail in the majority of the terrestrial environment of Kuwait. These processes include soil salinization and waterlogging (agricultural areas), loss of top soils (through both wind and water erosion), soil crusting, sealing and compaction, soil mining, vegetation degradation and loss of biodiversity. Several biophysical and socioeconomic land degradation indicators were identified by several authors, e.g., Khalaf et al. [5][6][7][8][9], Brown and Porembski [10,11], Al-Dousari, Al-Awadhi et al. [12,13], ; Omar et al. [1,14] , Misak [4], Al Dousari, Khalaf et al. [15], Misak et al. [15], the Kuwait National Committee for Combating De-

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Reversing the processes of land degradation through serious and sustainable control measures, as well as appropriate land use planning are the most significant challenges facing the real development of the terrestrial environment of Kuwait. The current study indicates that the total length of off-road vehicles is around 14,774.67 Km ( 0.98 Km/Km 2 ) of terrain environment of Kuwait

Remote Sensing and Geographic Information System
This study aims to detect and identify the land degradation hotspots (LDH). For this purpose, a low spatial resolution satellite image (Landsat 8, 25 September 2017, 15 m resolution) was used for the detection and delineation of hotspots and the analytical potential of GIS was effectively used to produce the final analysis and design in the form of maps. The primary data was collected from the entire study area and has been identified the locations of the degraded areas using the global positioning system (GPS) with extreme precision (latitude and longitude coordinates) and was saved in the system as a layer. For identification of hot spots using remote sensing, some observable ground objects were delineated. These include large trucks, water tankers, caravans, water wells, livestock sheds, portable livestock shelters and stores of animal feeds.
These objects which represent the tools for camping and grazing in the desert appear as black dots on the satellite image; therefore, the areas where the black dots appear on satellite image densely and confirmed by field survey are defined as hotspots where the soil and vegetation cover in these areas were subjected to severe deterioration due to human actions. The (ArcGIS S/W 10.5) was used in the current study to integrate the information of ground truth and satellite image to create a hotspots map. Three GIS map layers were overlayed on the hotspots map. These are offroad vehicles, soil types, and vegetation cover (Figures 4,8 & 9) respictively. These maps gave answers to many questions related to the extent of deterioration and its causes in the study area, and the economic, environmental and social impact on the Kuwaiti environment, then to determine the control measurements by the decision makers to mitigate and reduce this deterioration.  (Table 1).             (Table 3) [17 -28].

Soil Degradation
The results of the present study indicate that the area of soil degradation is 7590.3 Km 2 (47% of the terrestrial environment) ( Figure 8) and (Table 4).

Vegetation Degradation
The results of the present study indicate that the area of vegetation degradation is 7590.3 Km 2 (48.7% of the total vegetation cover) ( Figure 9) and (