Forthbank Wind Energy Development - Partnerships for Renewables

Forthbank Wind Energy Development
The Zone of Theoretical Visibility of the Wind Energy Proposal
9.3.42 The proposed wind energy development is located on the lower level on the River Forth
floodplain, the ZTV pattern stretches from Highlands (north-west) over the flat Lowlands to the
Uplands (south-east). This low-lying location greatly reduces their prominence across the
surrounding landform. This can be seen in the contained extent of the ZTV as shown in Figure
9.7 (hub height) and Figure 9.8 (blade tip).
9.3.43 ZTVs within 10km study area, in 1:80,000 scale from upper arc of blade tip is presented in
Figure 9.9.
9.3.44 ZTVs within 35km study area, in 1:50,000 scale both from hub height and from upper arc of
blade tip are presented in Appendix 9.2 and Appendix 9.3 respectively.
9.3.45 The pattern of the landform on which the Ochil Hills’ ridges run in a north to north east direction
has added to the limited visibility by screening extensive areas to the north that lie outwith the
immediate range of the valley landscape. Lowland Hills (Touch Hills and Kilsyth Hills) contain
the visibility to the west. Upland Hills (Cleish and Benarty Hills) prevent any increase to the
visibility line to the east.
9.3.46 The ZTV pattern draws out the spread of the low flat carseland of the River Forth from the
north-west to the south-east direction across the study area. The ZTV cover over the carseland
of the River Forth is expressed by steady (homogenous) intense pattern, which begins to break
as the landscape begins to increase in height above the River Forth Valley floor. All other main
river corridors (River Carron, Devon Water, Allan Water and the River Teith) remain outwith the
ZTV in the study area.
9.3.47 Potential visibility immediately to the north of the proposed wind energy development site is
indicated in long bands running along the southern foothills of the Ochil Hills. The volcanic
outcrops of the Campsie Fells and Gargunnock, Touch, Fintry and Kilsyth Hills form an abrupt
boundary to the west of the study area, reaching a height of almost 600m in places. The ZTV
cover to the west on these Lowland Hills is scattered along the high tops and their slopes. To
the east the ZTV captures the Upland Foothills and Slopes. The ZTV stretches along the
northern boundary line of the Slamannan Plateau above the River Avon. The rise of the
plateau landform obstructs theoretical visibility further to the south and south west.
9.3.48 The ZTV shows the theoretical visibility of the proposed wind energy development. Field
surveys have been undertaken to verify potential views on the ground and to appraise the
overall actual visibility of the proposed wind energy development.
Visual Assumptions and Limitations
Earth Curvature and Refraction of Light
9.3.49 The Visual Analysis of Windfarms: Good Practice Guidance (Technical Appendix F1) explains
“OS co-ordinates are not fully 3-Dimensional. The northing and easting define a point on a
plane corresponding to the OX transverse Mercator map projection and the altitude above OS
datum is measured above an equipotential surface passing through the OS datum point at
November 2010 Chapter 9 Page 33
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