We study coastal gullies along the Canterbury coast of New Zealand using field observations, sample analyses, drones, satellites, geophysical instruments and modelling. We show that these coastal gullies form when rainfall intensity is higher than 40 mm per day. The coastal gullies are formed by landslides where buried channels or sand lenses are located. This information allows us to predict where coastal gullies may form in the future.

In this work, we use 3D point clouds to detect topographic changes across the surface of a rock glacier. These changes are presented as the relative contribution of surface change during a 3-week period to the annual surface change. By comparing these different time periods and looking at change in different directions, we provide estimates showing that different directions of surface change are dominant at different times of the year. This demonstrates the benefit of frequent monitoring.

Arid ecosystem health is a complex interaction between vegetation and climate. Coupled with impacts from grazing, it can result in quick changes in vegetation cover. We present a wind erosion and vegetation health model with active grazers over 100-year tests to find the limits of arid environments for different levels of vegetation, rainfall, wind speed, and grazing. The model shows the resilience of grass landscapes to grazing and its role as an improved tool for managing arid landscapes.

This study demonstrates an innovative methodology to estimate the formative discharge of alluvial rivers from remote sensing images. We have developed an automated algorithm in Python 3 to extract the width of a river channel from satellite images. Finally, this channel width is translated into discharge using a semi-empirical regime equation developed from field measurements and threshold channel theory that explains the first-order geometry of alluvial channels.

Coastal marshes are valuable natural habitats with normally dense vegetation. The presence of bare patches is a symptom of habitat degradation. We found that the occurrence of bare patches and regrowth of vegetation is related to spatial variations in soil surface elevation and to the distance and connectivity to tidal creeks. These relations are similar in three marshes at very different geographical locations. Our results may help nature managers to conserve and restore coastal marshes.

Sandy coasts are areas that undergo a lot of changes, which are caused by different influences, such as tides, wind or human activity. Permanent laser scanning is used to generate a three-dimensional representation of a part of the coast continuously over an extended period. By comparing three unsupervised learning algorithms, we develop a methodology to analyse the resulting data set and derive which processes are dominating changes in the beach and dunes.

Existing ways of modeling the flow of water amongst landscape depressions such as swamps and lakes take a long time to run. However, as our previous work explains, depressions can be quickly organized into a data structure – the depression hierarchy. This paper explains how the depression hierarchy can be used to quickly simulate the realistic filling of depressions including how they spill over into each other and, if they become full enough, how they merge into one another.

Understanding soil erosion and suspended sediment transport is an important issue in terms of soil and water resources management. This study analyzes the impact of choices made during numerical model setup on the modeled suspended sediment dynamics at the outlet of two mesoscale watersheds. While the modeled liquid and solid discharges were found to be sensitive to these choices, the actual location of sediment sources in each catchment was the most important feature.