TOPIC 5 Flashcards
• 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
• Angles between adjacent lines in a closed polygon.
• They may be measured clockwise or counterclockwise.
• 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.
Interior Angles
• Angles located outside a closed polygon.
Exterior 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.
• ___ 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.
• 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 line. (Ghilani & Wolf, 2012)
Meridian
Types of Meridians:
- True Meridian
- Magnetic Meridian
- Grid Meridian
- Assumed Meridian
• Also called astronomic or geographic meridian.
• This line passes through the geographic north and south of the earth and the observer’s position.
• The generally adapted reference line in surveying.
• The direction of ____ is invariable and unchanged regardless of time.
•is used for markings of land boundaries.
True Meridian
• A line of reference parallel to the magnetic lines of force.
• is not parallel to the True meridian.
• This utilizes the magnetic needle of a compass to locate the magnetic north.
• Used in rough surveys since the ___ changes constantly along with the location of the magnetic poles.
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)
•Parcel size is an intrinsic constraint on a site’s development potential.
•Smaller sites,
Parcel Size and Shape
•Spatial variation in a site’s elevation creates slopes that have both a gradient and an orientation.
•In site planning, moderate (8 to 15%) to steep slope (15 to 25%) would require soil protection or stabilization while flat terrain (1%) would be challenging in terms of drainage.
Slopes
•Slope orientation of the compass direction that the slope faces (for example, north or northeast).
•Aspect influences microclimate by affecting the amount of solar radiation striking the site
Aspect
•Topography and landform can be analyzed by…
- is a drawing made on a plane, which vertically cuts through the earth and/or an object like a building.
•The ground line delineates the interface between earth and space and illustrates the relief of the topography.
Constructing a Section
- Indicate the cutting plane.
- Draw parallel lines according to the contour interval and proposed vertical scale.
- Project perpendicular lines from the intersection of the contour line with the cutting plane to the corresponding parallel line.
- Connect the points to complete the section and delineate the ground line.
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Drawing a Section
- All points on the same contour line are at the same elevation.
- Every contour line is a continuous line, which forms a closed figure, either within or beyond the limits of the map or drawing.
- Two or more contour lines are required to indicate three-dimensional form and direction of slope.
- The steepest slope is perpendicular to the contour lines. This is a result of having the greatest vertical change in the shortest horizontal distance
- Water flows perpendicularly to contour lines.
- For the same scale and contour interval, the steepness of slope increases as the map distance between contour lines decreases.
- Equally spaced contour lines indicate a constant, or uniform, slope.
- Contour lines never cross except where there is an overhanging cliff, natural bridge, or other similar phenomenon. Characteristics of Contour Lines
- In the natural landscape, contour lines never divide or split. However, this is not necessarily true at the interface between the natural and built landscape.
Characteristics of Contour Lines
In analyzing a landform, certain geomorphic features are described by distinct contour configurations referred to as contour signatures.
• Ridge
•Valley
Summit
•Depression Contour Signatures and Landform Ridge and Valley
Contour Signatures and Landform
is a landform, such as a knoll, hill, or mountain, which contains the highest point relative to the surrounding terrain.
Summit
are characterized by contour lines that are spaced at increasing distances in the downhill direction.
•This means that the slope is steeper at the higher elevations and becomes progressively more flat at the lower elevations.
is the reverse of a concave.
Concave and Convex Slopes
•Along the __, contour lines are spaces at equal distances.
• The change in elevation occurs at a constant rate
Uniform Slope
is raised, elongated landform. At the narrow end of the form the contours point in the downhill direction.
Ridge
will be relatively parallel, and there will be a high point or several high points along the ridge.
contours along the sides of the ridge
is an elongated depression that forms the space between two ridges.
valley
are interconnected since the ridge side slopes create the valley walls. A valley is represented by contours that point uphill.
Valleys and ridges
is similar for both ridge and the valley so it is important to note the direction of slope
contour pattern
closed figures with the highest contour at the center Since the land slopes away in all directions, summits tend to drain well.
The contours form concentric
is a landform that contains the lowest point relative to the surrounding terrain.
•Graphically, the lowest contour is often distinguished by the use of hachures. Since ____ collect water, they typically form lakes, ponds, and wetlands.
depression
having contour lines are spaced at decreasing distances in the downhill direction. The ____ is flatter at the higher elevations and becomes progressively sleeper at the lower elevations.
Slope
