Managing gully erosion as an efficient approach to improving water quality in the Great Barrier Reef lagoon

[摘要] Gully erosion is an important contributor to sediments and nutrients entering the GBR lagoon. Gullies that formed up to 140 years ago are today continuing to expand, delivering an unacceptably high level of sediment and nutrient to the lagoon of the Great Barrier Reef. This report reviews recent sediment source tracing, erosion mapping and catchment modelling studies, finding that gully erosion contributes approximately 40% of all fine sediment to the GBR lagoon. This makes gully management a high priority for investments to reduce sediment loads.This report synthesises available information on the spatial locations, causes and control measures of gully erosion in GBR grazing lands. It is recommended to commission a comprehensive and substantial program demonstrating gully erosion remediation in priority management units, as a new direction to reliably achieve substantial reductions in gully sediment yield. This would be targeted to management units that have the highest length-specific gully contribution to sediment exports. A combination of low technology revegetation techniques is recommended to be implemented by or in partnership with land managers, including fencing, seeding and small sediment trapping structures.It is also recommended to target other grazing practice change programs to properties making high gully erosion contribution to GBR sediment exports. This will improve their effectiveness at reducing sediment loads, and help to support the program recommended above.

[发布日期] 2015-03-19 [发布机构] CSIRO

[学科分类] 地球科学(综合)