PPT 5 Flashcards
Types of Base Map
Sketch Plan
Relocation Plan
Subdivision Plan
Consolidation Plan
This may be a rough sketch or any official base plan
of a property.
Sketch Plan
A sketch plan of a property based on the relocation survey.
Relocation Plan
From subdivision survey or splitting a tract of land into smaller parcels.
Subdivision Plan
Re-mapping of two or more adjacent lots or parcels
of land, combining them into one larger parcel.
Consolidation Plan
Components of a Lot Plan
Technical Description
Benchmark
Sketch
Property Owner
Vicinity Map
Approval of LRA
Location
Lot No. / Title No.
Lot Area & Scale
Surveyor
How do we Sketch the Plan?
Direction of Lines
1. Interior Angles
2. Deflection Angles
3. Angles to the right
4. Bearing Azimuth
- Angles between adjacent
lines in a closed polygon. - They may be measured
clockwise or counter-
clockwise. - Re-entrant angles are
interior angles greater than
180 degrees. - The sum of the interior angle
of any polygon is equal to
(n - 2)(180 degrees), where
n is the number of sides.
Exterior Angles
* Angles located outside a
closed polygon.
Interior Angles
- The angles between a line and the prolongation of the preceding
line. - May be turned to the right (clockwise) or turned to the left
(counterclockwise) and appended with letters R or L. - Right deflections have the opposite signs of left deflections
- Positive signs normally defines angle with deflection to the right.
- May have values 0 to 180 degrees but often not used to angles
greater than 90 degrees. - In a close polygon, the algebraic sum of the deflection angle should
always equal 360 degrees.
Deflection Angles
- These are angles measured clockwise from the preceding line to the
succeeding line. - This is also called Azimuths.
Angles to the Right
- Acute horizontal angles between the reference meridian and the line.
- Contains angles that are between 0 to 90 degrees.
- It always starts on either N or S and will turn E or W.
- Bearings can be measured in reference to True or Magnetic meridian.
Bearings
- The angle between the meridian and the line measured clockwise.
- Contains angles that are between 0 to 360 degrees.
- Reference meridian can be the N or S.
- Azimuths can be true, magnetic, grid or assumed.
Azimuth
An imaginary line
between the North Pole
and the South Pole, drawn
on maps to help to show
the position of the place.
In surveying, it is the
direction of a line defined
by the horizontal angle
between the line and an
arbitrarily chosen
reference
Meridian
Types of Meridians:
- True Meridian
- Magnetic Meridian
- Grid Meridian
- Assumed Meridian
Also called astronomic or
geographic meridian.
True Meridian
- A line of reference parallel to the
magnetic lines of force. - Magnetic meridian is not parallel
to the True meridian.
Meridian Magnetic
A fixed line of reference
parallel to the central
meridian of a system plane
rectangular coordinates.
Grid Meridian
- This is an arbitrary chosen reference point
taken for convenience. - This utilizes a well defined and permanent
reference point. - Applicable plane surveys of limited extent.
Assumed Meridian
are control points of permanent
location where other surveys are
referenced from.
Bureau of Lands Location
Monument (BLLM)
Three attributes of a topographic map
- Elevation
- Slope
- Aspect
*Elevation data are portrayed on topographic
maps as contour lines and spot elevations.
*For site planning purpose, an effective way to
visualize topographic relief is to create a
choropleth map of elevation.
Elevation
*A contour line is the graphic representation of a contour on a plan or
map indicating locations with equal elevation.
Contours and Form
*Spatial variation in a site’s elevation
creates slopes that have both a gradient
and an orientation.
Slopes
*Slope orientation of the compass direction that the slope faces (for
example, north or northeast).
Aspect
Contour Signatures and Landform
- Ridge
*Valley
*Summit
*Depression
______ is raised, elongated landform. At
the narrow end of the form the contours
point in the downhill direction.
Ridge
______ is an elongated depression that
forms the space between two ridges.
valley
_______ is a landform, such as a knoll, hill, or mountain, which contains the highest point relative to the surrounding terrain.
Summit
________ is a landform that contains the lowest point relative to the surrounding
terrain.
depression
_______ are characterized by
contour lines that are spaced at increasing
distances in the downhill direction.
Concave slopes
______ is the reverse of a
concave.
convex slope
- Along a _______, contour lines are
spaces at equal distances. - The change in elevation occurs at a
constant rate.
Uniform Slope
