The ISC2010_VEGETATION_OVERHANG polygon features represent areas of vegetation that partially or wholly overhang the Stream Bed.  The data set contains the whole vegetation polygon, not only the overhanging part of the polygon. Candidate vegetation is defined as vegetation cover greater than 20%.  Vegetation Overhang has been mapped within a 200m buffer of the ISC2010_STREAMBED_WIDTH feature. This data set is derived from source Fractional Cover raster data. The data set also contains additional polygon divisions created by the introduction of Side and 200m buffer boundaries. Small polygons (<10m2) that were created by the introduction of these boundaries have been removed.

River condition in Victoria is assessed every 5 years using the Index of Stream Condition (ISC). The Department of Environment and Primary Industries (DEPI) developed a methodology to assess the Physical Form and Riparian Vegetation components of the ISC using remote sensing data, specifically LIDAR and aerial photography. 

A State Wide mapping project was undertaken in 2010-13 to accurately map the Physical Form and Riparian Vegetation metrics of the ISC . Other ISC metrics were not assessed in the project and were derived from other sources.

The Physical Form and Riparian Vegetation Metric  products are a combination of mapped Vector and Raster data as well as Tabular Summary Statistics about the mapped features. In the context of the project, the term Metrics is used to refer to both the mapped features and the summary statistics. 

Remote sensing data used includes 15cm true colour and infra-red aerial photography and four return multi-pulse LiDAR data.  This source data was used to derive a variety of Raster data sets including Digital Terrain Models, Slope, Vegetation Height and Vegetation Cover.  The Digital Terrain and Slope rasters were used to map Physical Form metrics including Stream Bed, Top of Bank and River Centre Lines while the Vegetation Height and Cover rasters were used to map the Riparian Vegetation metrics.
The Project Report "Aerial Remote Sensing for Physical Channel Form and Riparian Vegetation Mapping" describes the remote sensing and mapping approach used to create this data set.

The ISC2010_VEGETATION_OVERHANG polygon features represent areas of vegetation that partially or wholly overhang the Stream Bed.  The data set contains the whole vegetation polygon, not only the overhanging part of the polygon. Candidate vegetation is defined as vegetation cover greater than 20%.  Vegetation Overhang has been mapped within a 200m buffer of the ISC2010_STREAMBED_WIDTH feature. This data set is derived from source Fractional Cover raster data. The data set also contains additional polygon divisions created by the introduction of Side and 200m buffer boundaries. Small polygons (<10m2) that were created by the introduction of these boundaries have been removed.

River condition in Victoria is assessed every 5 years using the Index of Stream Condition (ISC). The Department of Environment and Primary Industries (DEPI) developed a methodology to assess the Physical Form and Riparian Vegetation components of the ISC using remote sensing data, specifically LIDAR and aerial photography. 

A State Wide mapping project was undertaken in 2010-13 to accurately map the Physical Form and Riparian Vegetation metrics of the ISC . Other ISC metrics were not assessed in the project and were derived from other sources.

The Physical Form and Riparian Vegetation Metric  products are a combination of mapped Vector and Raster data as well as Tabular Summary Statistics about the mapped features. In the context of the project, the term Metrics is used to refer to both the mapped features and the summary statistics. 

Remote sensing data used includes 15cm true colour and infra-red aerial photography and four return multi-pulse LiDAR data.  This source data was used to derive a variety of Raster data sets including Digital Terrain Models, Slope, Vegetation Height and Vegetation Cover.  The Digital Terrain and Slope rasters were used to map Physical Form metrics including Stream Bed, Top of Bank and River Centre Lines while the Vegetation Height and Cover rasters were used to map the Riparian Vegetation metrics.
The Project Report "Aerial Remote Sensing for Physical Channel Form and Riparian Vegetation Mapping" describes the remote sensing and mapping approach used to create this data set.

The ISC2010_VEGETATION_OVERHANG features are used in the assessment of the Vegetation Overhang sub-index where the linear proportion of vegetation that overhangs the stream bed contributes to the Vegetation Overhang Score.

+/- 1m

The UniqueID that describes the Basin and Reach that each Vegetation Overhang polygon falls in is recorded.

Vegetation Overhang has been mapped the same way across the entire ISC2010 network.  Vegetation Overhang polygons were extracted from source rasters on a Reach by Reach basis using a 200m buffer and then combined. At Reach ends, the extraction by 200m buffer has resulted in some polygons being represented more than once - according to how many buffered Reaches the polygon falls into. This is evident at Reach ends and river junctions. Duplicate polygons will be shown to belong to more than one Reach by UniqueID.

Dataset Source: Vegetation Overhang is derived from from the Overall Fractional Cover Count Raster data set, a derivative of the LiDAR source data.

Dataset Originality: Derived

                            
                              Related Documents: None

The Product Description  "ISC2010 Remote Sensing Metrics" describes the remote sensing and mapping approach used to create this and all other ISC2010 data sets.
http://ics.water.vic.gov.au/ics/

http://ics.water.vic.gov.au/ics/