Grosvenor Ecological Monitoring Program

Specifications

• Client: Anglo Coal
• Scope:

  Anglo American has engaged Verterra to develop a rolling program for assessment, monitoring and assessment of Spoil stockpiles and subsidence panels (inundation panels). An initial assessment of 9.75-ha of Endangered Remnant Vegetation (RE 11.3.1) was carried out on 16th April 2018 using a UAV platform with a visible colour (red, green, blue) and multispectral camera (green, red, red edge, near infrared) payload. Imaged areas incorporated a subsided area with varying exposure to inundation and an adjacent control area at the natural land surface.  Analysis of captured RGB (visible) images and vegetation indices constructed from multispectral imagery enabled stratification of the area into a number of inundation/disturbance classes and additionally, previously cleared areas (not related to subsidence or inundation) were also identified. Vegetation condition demonstrated declining vigour and cover with increasing level of inundation. Modified Soil-Adjusted Vegetation Index (MSAVI) a measure of vegetation cover and health was gridded across the area of interest.

   

• Challenge:

  The Environmental Authority (EA) conditions for Grosvenor limit the impact of mining activities on remnant vegetation within the mining lease.  Subsidence of the natural land surface in areas above the longwall operations has resulted in seasonal inundation and vegetation mortality, including areas of Category A or B area endangered regional ecosystem type 11.3.1 (Brigalow).  Draining these areas is necessary to prevent continuing mortality, but the subsided area remains a local drainage depression, and soil conditions may remain saturated in the absence of visible surface water.  The extent and long-term impact of this seasonal inundation is not known.  

• Solution:

  Verterra proposed carrying out baseline assessment and subsequent time-series monitoring of vegetation health to inform management decisions regarding larger-scale interventions.

• Benefit to Client:

  This initial monitoring round has established MSAVI values that provide a baseline for the system under the principal stressor (inundation). This will allow comparison after a period of drying out to establish resilience of the vegetation community to inundation and capacity for recovery. The proposed subsequent time-series monitoring of vegetation health will inform Anglo mangement decisions regarding larger-scale interventions.

• Market Sector: Mining
• Capabilities:
  • Mine site, tailings dam and degraded land rehabilitation
  • Environmental surveys, benchmarking and biodiversity assessment
• Location: Queensland
• Year: 2018