Getting to the root causes of soil erosion using high-res remote sensing

Soil erosion processes are notably active in New Zealand: our steep slopes, generally weak sedimentary rocks, and high annual rainfall totals including frequent large rainfall events, underscored by a history of vegetation clearance for agriculture, mean that around 192 million tonnes of soil on agricultural land are lost to erosion every year.

Large rainfall events in New Zealand commonly trigger hundreds to thousands of shallow landslides, especially in more marginal pastoral hill country, causing significant damage to land and infrastructure as well as contributing large quantities of sediment to aquatic environments. These landslide inventories are used to determine which land is most susceptible to shallow landsliding to support targeting of erosion control measures.

Within the Ministry of Business, Innovation and Employment research programme Smarter Targeting of Erosion Control (STEC), scientists at Manaaki Whenua have been using new remote sensing techniques to fill these data gaps, mapping over 100,000 landside scars from high-resolution satellite or aerial imagery across the North Island. Continue reading