Erosion and sedimentation are major global problems that impose a high cost on the functioning of ecosystems (e.g. aquatic, coastal, and nearshore marine ecosystems) and economic sectors (e.g., agriculture, water supply, electric power generation, and navigation). Natural sediment delivery can also be a beneficial process. For instance, sediment pulses can restore fertility to floodplain farmland, and reduced sediment delivery to deltas can lead to loss of coastal wetlands and the critical services they provide.
Sediment delivery as a beneficial or detrimental service: Sediment regulation can be classified as either a beneficial or detrimental service, depending on whether the user benefits from or is harmed by sediment delivery. Running the sediment flow model allows the user to map spatial connections between sources of sediment, areas that promote sediment deposition, and users that benefit from or are harmed by sediment delivery. We can also run the erosion source model both with and without existing vegetation, showing the benefit of existing vegetation in erosion control or the benefits of increasing vegetation cover on erosion-prone surfaces.
Multiple benefits from sustainable forestry and agriculture: Because of the strong connections between areas of high biodiversity, carbon storage, and erosion control, researchers in many regions are exploring the overlap between areas that provide these services. ARIES models can help the development of economic incentives for forestry and agricultural practices that reduce erosion while improving carbon sequestration and storage, biodiversity, and other ecosystem services.
Intelligent model selection: Past ecosystem services modeling projects have often relied on the Universal Soil Loss Equation or Revised Universal Soil Loss Equation (USLE/RUSLE) to estimate erosion. While RUSLE works well in certain environments, it has several well-known limitations. ARIES can use artificial intelligence to select the right model for the right context: for instance, to use RUSLE to estimate erosion loss in relatively level environments, and to use data-driven Bayesian models to estimate erosion loss on steeply-sloped environments where RUSLE is known to perform poorly.
Sedimentation is particularly problematic in Madagascar, where high rates of deforestation and low natural rates of forest regrowth have led to high levels of erosion. Excess sedimentation can be particularly damaging to rice fields and to coastal and marine ecosystems and the services they provide.
In the Dominican Republic, sediment loss from intensive agricultural practices is impacting hydroelectric production in parts of the country, impeding development efforts and reducing human well-being. Mapping the costs and benefits of erosion can show the added economic and environmental benefits of shade-grown coffee over intensive agriculture.
In Western Washington, sedimentation is important for both providing beneficial coarse sediments (e.g., gravels) for salmon spawning and for avoided siltation of habitat for salmon and other economically beneficial species. Sediment delivery can also have negative impacts on drinking water intakes and recreational use and hydroelectric power generation from reservoirs.
Major fires in 1996 and 2002 led to sedimentation of several major water supply reservoirs in Colorado, costing tens of millions of dollars for dredging. The USDA Forest Service is working with local water utilities to proactively manage forests surrounding major drinking water reservoirs. Biophysical modeling of sedimentation and its impacts could be used to help guide such management.