Geographic Information
Systems (GIS) are computerised management systems for spatial data, offering
improved data management, extensive data manipulation techniques and greater
understanding of data. At the Wangaloa Coal Mine, South-East Otago, ArcGIS is being used to manage,
integrate, analyse and visualise the diverse range of datasets being generated
from an interdisciplinary research team. GIS will assist with identifying
spatial and temporal patterns associated with the current site rehabilitation
strategy. This paper will present an overview of how GIS can be a useful tool
for understanding ecological recovery during mine site rehabilitation.

The Wangaloa opencast coal mine, owned by Solid Energy NZ
Ltd, was closed in 1989 after more than 40 years of operation. Rehabilitation
efforts involving more than 60 000 native plants began in October 2001. At
Wangaloa sample points were randomly selected at 100 m intervals and recorded
using a differential GPS. Plant, soil and invertebrate data have been collected
at each sample point. Plots of 8 - 9 plants have been established within
approximately 5 m of each sample point. Since September 2003 seasonal monitoring
of plant growth and survival has been carried out. Chemical and physical
datasets have been generated from soil collected in June and December 2003 for
each sample point. A more restricted dataset is being generated for soil
collected on a seasonal basis from March 2004. Plant and soil characteristics
from these datasets have been attached to each sample point and GIS layers have
been created. Relationships between data layers can be explored based on their
spatial patterns. Examples presented from Wangaloa include distribution of
planting success and temporal variation; temporal change in pH; interpolated pH
map; digital elevation model; relationships between planting success and growth
with pH and organic matter. GIS is proving to be a valuable tool on the
integrated project at Wangaloa.