Nathalie Vriend and Stephanie McNamara for being excellent, committed researchers in the field of geomorphology. They are going a mile wide and a mile deep in the complexities of sand dunes. These living reefs and islands comprise roughly 5% of the Earth’s land surface. These aren’t just picturesque canvases, they are active ecosystems that can shift radically in the span of a few years. Her team’s research encompasses all southern deserts. They particularly hone in on the Mojave Desert and Great Sand Dunes National Park and Preserve in Colorado, tracking the movement and behavior of these sandy behemoths.
Sand dunes, contrary to popular perception, are not static entities. They can migrate as much as a few feet to dozens of feet per year in some locations. This extraordinary movement is shaped by a rich interplay of forces — wind patterns, climate change, urbanization. Vriend and her team are leading the world in research on how these factors control sediment transport and dune dynamics. We are still discovering the ways in which these changing muscle structures respond to encroaching environments. It looks at what these projects mean for the ecosystems and communities around them.
The Impact of Climate Change on Dune Dynamics
Science is clear that under climate change, deserts are growing quickly. At the same time, human land-use practices such as deforestation are worsening this shocking trend at a staggering pace. More than 200 million people around the world already suffer the consequences of accelerated desertification as a result of this combination of causes. In Mauritania, where the Sahara Desert is pushing southward at an accelerated pace, entire communities are being swallowed by shifting sand, threatening to bury the capital city of Nouakchott.
As Vriend’s research underscores, it’s more important than ever to understand how sand dunes are evolving. These dynamics are especially important in areas being hit hard by climate change. The scientists acknowledge that these dunes pose serious risks to the human communities adjacent to these features. They equally fuel the ecological transformations that take place around them. As deserts advance deeper into former farmlands, those who live on the frontline of this ecological march are forced to confront new realities written by changing dunes.
During the course of their research, Vriend and her team found that up to two-thirds of a dune can remain at rest. This occurs in times of progressive environmental reversal. This new complexity creates a major hurdle for scientists hoping to model dune behavior with precision. Their research points to how the complexities of sediment transport can impact anything from the local climate to biodiversity.
Innovations in Dune Research
The team’s research has already led them to some extraordinary places — most notably, the iconic singing dunes of the Mojave Desert. On her most recent research expedition, McNamara hiked to the summit of one of these extraordinary coral formations. While there, he recorded the rich variety of acoustic phenomena. These whistling sand dunes create noises comparable to musical notes when sand particles shuffle against each other. The events draw many thousands of visitors. They provide revelations about the physical properties and behaviors of sand at extreme conditions.
To further understand dune dynamics, Vriend and former graduate student Karol Bacik have summarized current scientific knowledge in a comprehensive paper. This work provides a strong framework for new studies to build off. It’s intended to steer conservation around the world toward places affected by desertification. In particular, their research looks at how various impediments can redirect the flow of sand dunes. They suggest ways to reduce the damage caused by spreading deserts.
Scholars have conducted field tests of a wide variety of approaches to control sand dune movement. This includes building fences to hold sand and planting vegetation to stabilize moving sands. Many of these approaches have proven effective in local contexts. Yet all too often, they fail to take into account the complex relationships that exist between dunes and their surroundings.
Diverse Forms and Functions of Sand Dunes
Sand dunes can take on many forms from crescent shaped Barchan dunes to star shaped morphological giants, each with different properties and characteristics. Crescent-shaped barchans are one of the most readily identifiable types of sand dunes. Some appear like stardust, the ramparts of a castle at sunset—a variety characteristic of the evolution of desert ecosystems. Each form describes a different tale revolving around available wind patterns and sediment supply in their surrounds environment.
Familiarizing oneself with each of these varied shapes is an important task for academics such as Vriend and McNamara. Different dune types respond differently to environmental pressures, which can help predict how landscapes might evolve under changing climatic conditions. Their multi-year studies will help develop a bigger and fuller picture of these natural wonders.
Vriend and her team are pushing new frontiers in their work. Their findings will be key to developing effective policies to fight desertification while protecting at-risk communities. They are making new discoveries on the whys and hows of sand dune movement. In the process, they hope to offer helpful lessons for navigating our world’s changing terrain in the face of accelerating climate impacts.