Transcript 06_fieldwork and survey.ppt

Field Work and Survey
07 August 2016
O-Map Seminar, Temuco, Chile
2006
1
Planning the field work
Size of area
Type of terrain
Quality of base map
Season and weather
Experience of mappers
07 August 2016
O-Map Seminar, Temuco, Chile
2006
2
Planning the field work
Time for survey can vary from 10
hours up to 60 hours/km2
Do not work in the field more than 6
hours a day
Draw the survey immediately after
fieldwork
Plan extra days, due of bad weather
conditions, unexpected difficulties
07 August 2016
O-Map Seminar, Temuco, Chile
2006
3
Planning the field work
Example:
Area to be surveyed:
10 km2
Time for 1 km2
25 hrs
Time for 1 day
6 hrs
Total hours (10 x 25 / 6)
42 days
Unforeseen circumstances
8 days
Total
50 days
or a period of 1 year, if you spend every week 1 day !!!
07 August 2016
O-Map Seminar, Temuco, Chile
2006
4
Organization of field work
If several mappers are involved in the
field work, it is impossible to get a consist
map!
07 August 2016
O-Map Seminar, Temuco, Chile
2006
5
Organization of field work
Coordination
define leader (coordinator)
Agreement of classification
Before field work starts, hold a common
meeting in the area to discus the level of detail
Division of area
use clear boundaries like streams, roads or
open areas
Checking process
regular checks by the coordinator
Field work draft
07 August 2016
use the same
symbols and colors
O-Map Seminar, Temuco, Chile
2006
6
Preparation for field work
Preparation of fieldwork
•
Make a (color) copy of the original base map
•
Adjust the magnetic north line on the copy (see
lecture template)
•
Cover the copy with a self adhesive transparency
07 August 2016
O-Map Seminar, Temuco, Chile
2006
7
Field Work
Stages of Survey
Exploration
All mappers together (Agreement of
classification)
Checking Accuracy of the base map
Subdivide the area
Not larger than a days work (6 hours)
Progress of survey
07 August 2016
O-Map Seminar, Temuco, Chile
2006
8
Personal Equipment
Clothing
Trousers (long legs) and sweat-shirt (long
sleeves) because of ticks, poison eve or
oak
Orienteering shoes or hiking shoes
back bag
07 August 2016
O-Map Seminar, Temuco, Chile
2006
9
Survey
07 August 2016
O-Map Seminar, Temuco, Chile
2006
10
Survey Equipment
Basic survey equipment
Orienteering compass or sighting
compass
Map board (plastic)
Pencil (3H to 7H, depends on
transparency)
Colored pencil (red, blue or green
0.5 mm leads)
Ruler
Use as less equipment as possible =
Eraser
(rubber)
better handling
07 August 2016
O-Map Seminar, Temuco, Chile
2006
11
Survey Equipment
Digital Rangefinder
e.g. Geovid (Leica)
Tricky to handle with other equipment (map
board)
Global Positioning System (GPS):
Selected Availability has been switched off in
spring 2000
Not sufficient accuracy under a dense canopy of
leaves
Good accuracy in open area, however in this
case photogrammetric base maps would be
better (more details)
O-Map Seminar, Temuco, Chile
Pen Computer
2006
07 August 2016
12
Survey Techniques
Basic measuring techniques
Compass bearing
Fixing position of lines and points
Accuracy -/+ 1 degrees
Not more than 150 m
Pace counting / Estimations
affected by several factors (steep terrain, rough
ground)
Not more than 100 m
07 August 2016
O-Map Seminar, Temuco, Chile
2006
13
Survey Techniques
General techniques
Forward bearing (angle and distance)
Traverse (angle and distance)
Triangulation (3 angles)
Rectangular bearing (2 distances, 90°-angle)
Elongating
07 August 2016
O-Map Seminar, Temuco, Chile
2006
14
Survey Techniques
Forward bearing (angle and distance)
07 August 2016
O-Map Seminar, Temuco, Chile
2006
15
Survey Techniques
Traverse (1)
07 August 2016
O-Map Seminar, Temuco, Chile
2006
16
Survey Techniques
Traverse (2)
Measuring
distance from
the water
whole to the
intersection
for controll
07 August 2016
O-Map Seminar, Temuco, Chile
2006
17
Survey Techniques
Traverse (3)
Adjusting
traverse
07 August 2016
O-Map Seminar, Temuco, Chile
2006
18
Survey Techniques
Traverse (4)
Adjusting
features
07 August 2016
O-Map Seminar, Temuco, Chile
2006
19
Survey Techniques
Triangulation (3 angle)
07 August 2016
O-Map Seminar, Temuco, Chile
2006
20
Survey Techniques
Triangulation (3 angle)
07 August 2016
O-Map Seminar, Temuco, Chile
2006
21
Survey Techniques
Triangulation: Best Angle = 60°
large error
large error
07 August 2016
smallest error
O-Map Seminar, Temuco, Chile
2006
22
Survey Techniques
Rectangular bearing (2 distances, 90°-angle)
07 August 2016
O-Map Seminar, Temuco, Chile
2006
23
Survey Techniques
Elongating with distance
07 August 2016
O-Map Seminar, Temuco, Chile
2006
24
Survey Techniques
Elongating without distance
07 August 2016
O-Map Seminar, Temuco, Chile
2006
25
Survey Techniques
Survey of landforms
07 August 2016
O-Map Seminar, Temuco, Chile
2006
26
Survey Techniques
Survey of landforms
07 August 2016
O-Map Seminar, Temuco, Chile
2006
27
Survey Techniques
Survey of landforms
Guide
Lines
07 August 2016
O-Map Seminar, Temuco, Chile
2006
28
Progress of Survey
1. Work round the perimeter, plotting
directions of lines and points,
classifying paths
2. Complete the survey with line features
3. Fill in point features
4. Classify vegetation
5. Complete contours
Experienced mappers will combine these
5 steps O-Map Seminar, Temuco, Chile
07 August 2016
2006
29
Progress of Survey
1. Work
round the
perimeter
07 August 2016
O-Map Seminar, Temuco, Chile
2006
30
Progress of Survey
2. Complete
line
features
07 August 2016
O-Map Seminar, Temuco, Chile
2006
31
Progress of Survey
3. Fill in
point
features
07 August 2016
O-Map Seminar, Temuco, Chile
2006
32
Progress of Survey
4. Classify
vegetation
07 August 2016
O-Map Seminar, Temuco, Chile
2006
33
Progress of Survey
5. Complete
contours
07 August 2016
O-Map Seminar, Temuco, Chile
2006
34