Exploring the Dunes: The Correlations between Vegetation Cover Pattern and Morphology for Sediment Retention Assessment Using Airborne Multisensor Acquisition

Abstract

Coastal sand dunes are highly dynamic aeolian landforms where different spatial patterns can be observed due to the complex interactions and relationships between landforms and land cover. Sediment distribution related to vegetation types is explored here on a single ridge dune system by using an airborne hyperspectral and light detection and ranging (LiDAR) remote sensing dataset. A correlation model is applied to describe the continuum of dune cover typologies, determine the class metrics from landscape ecology and the morphology parameters, and extract the relationship intensity among them. As a main result, the mixture of different vegetation types such as herbaceous, shrubs, and trees classes shows to be a key element for the sediment distribution pattern and a proxy for dune sediment retention capacity, and the anthropic fingerprints can play an even major role influencing both ecological and morphological features. The novelty of the approach is mostly based on the synergistic use of LiDAR with hyperspectral that allowed (i) the benefit from already existing processing methods to simplify the way to obtain thematic maps and coastal metrics and (ii) an improved detection of natural and anthropic landscape.

Ecology of inland sand dunes “nafuds” as a hyper-arid habitat, Saudi Arabia: Floristic and plant associations diversity

“…Although the terrain falls within the arid Saharo-Arabian phytogeographical zone and the majority of species belong to the Saharo-Arabian zone, there are intrusions of species from other phytogeographical zones such as Acacias and Astragalus of Somalia Masai, Mediterranean and Irano-Turanian zones respectively; this may be because Nafud Al-Urayq is considered a transitional zone or a midpoint between the Mediterranean and Saharo-Sindian flora of these neighboring zones (see Watts and Al-Nafie, 2003 , Elmefregy and El-Sheikh, 2020 , Valentini et al, 2020 ).…”

“…Different associations are proxies for dune sediment. These different associations can be characterized as open dwarf shrubland with spring ephemerals and contain a mixture of widely distributed plants in sandy soils and plants found in adjacent, non-dune habitats ( Al-Sodany et al, 2011 , Bowers, 1982 , Elmefregy and El-Sheikh, 2020 , El-Sheikh et al, 2010 , Valentini et al, 2020 , Vincent, 2008 ).…”

“…Several factors influence the conditions of sediment distribution and retention capacity, such as wind regimes, vegetation cover, runoff, and rainfall. Additionally, anthropogenic activities impact the morphological equilibrium of sand dunes as well as their water and nutrient distribution ( El-Sheikh et al, 2010 , Duran and Moore, 2013 , Elmefregy and El-Sheikh, 2020 , Valentini et al, 2020 ). Zhang and Baas (2012) estimated that vegetation cover of at least 20% played an important role in reducing wind-blown sand transport; thus, the vegetation cover functions as sediment biostabilization for the next serial stage of succession species ( Lancaster and Baas, 1998 , Nickling and Neuman, 2009 , Acosta et al, 2005 , El-Sheikh et al, 2010 , Leenders et al, 2011 , Elmefregy and El-Sheikh, 2020 ).…”

“… Zhang and Baas (2012) estimated that vegetation cover of at least 20% played an important role in reducing wind-blown sand transport; thus, the vegetation cover functions as sediment biostabilization for the next serial stage of succession species ( Lancaster and Baas, 1998 , Nickling and Neuman, 2009 , Acosta et al, 2005 , El-Sheikh et al, 2010 , Leenders et al, 2011 , Elmefregy and El-Sheikh, 2020 ). Therefore, Valentini et al (2020) stated that geomorphological processes as well as vegetation presence and absence mutually determine the evolution of dune systems, generally known as land–surface eco-morphodynamics. In this context, the spatial relationship between sediment distribution and vegetation cover (vegetated and non-vegetated areas) within dunes, especially inland “nafuds” in Saudi Arabia, still requires further investigation to determine spatial vegetation patterns.…”

An Interaction Methodology to Collect and Assess User-Driven Requirements to Define Potential Opportunities of Future Hyperspectral Imaging Sentinel Mission

“…Then, this application was fruitful to develop a proper way to treat all these heterogeneous data. However, it is important to highlight that user requirements are not static elements but they are, by their nature, in continuous evolution [126,129,133,149] depending on changes in user needs and progress in the technological capabilities adopted to develop the satellite-based EO products. At the same time, this aspect represents both a complexity and a richness.…”