AAIR Project: Task 2.1 Organisation and Contact Information

Name: Roger Dunham

Organisation: Department of Forestry, University of Aberdeen

Address:St Machar Drive, Old Aberdeen, Aberdeen. AB9 2UU

E-mail address: Alistair Law@aberdeen.ac.uk

MODELS USED FOR DATA ANALYSIS

Model Name: To be developed, II

Source of Model: New model (empirical)

Computer Language that the model is developed in: Excel 4

Hardware needed to run model: PC 386, colour graphics monitor

Data Inputs needed by model:

Tree height (metres)

Tree diameter (breast height, 1.3m)

Crown dimensions (depth, width, exposed surface area, metres or m2)

Model outputs

Tables/Statisics

Probable stability outcome - Stand, Snap or Uproot.

(single answer output, possible estimates of probability at a later stage)

Maps / GIS datalayers

Possibly: locations of sampled trees; locations of trees for which

assessments are carried out.

Accuracy/Sources of Uncertainty/Method of Handling

Tree height - field measures - standing +- 25cm (or better) using clinometer or laser

- fallen +-10cm using tape measure.

Tree diameter - cm rounded down using tape measure +-1cm Possible error if tree is

non-circular (see comments).

Breast height - estimated (not always using tape measure) +-5cm

Crown characteristics - only measured after felling: height - tape measure +- 10cm;

width - tape measure and human appraisal +-25cm; surface area - numerical computation.

Existing linkages between data (eg in databases) and software (eg databases/GIS/Statistical packages)

minitab <--> Excel 4 <--> Paradox

(ascii file) (direct transfer)

GIS Software used

Possibly: PC Arc/Info

Modelling Software used

Excel 4

Database Software used

Paradox for Windows

Any other comments

1. Inputs are all field or laboratory measurements.

2. Models are product of the Task (Task 2).

3. Crown characteristics: trees are felled before measures made. This leads to some

potential for error in assessing canopy width as some of the branches may not be flat on the ground.

Canopy height will be measured from the leader tip to both the lowest live whorl and the lowest live branch greater than 1cm in diameter.

Exposed surface area is that area of the crown which is considered to have been exposed to the wind when the tree was damaged. The calculation of surface area will be based upon 1metre interval measures of diameter, summed over the hieght of the canopy.