IA Land Surveyor flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Priority of boundary evidence

Courts generally rank evidence as natural monuments, artificial monuments, courses and distances, then area. Written calls control over area computations when conflicts arise in retracement.

Adverse possession Iowa

Iowa requires 10 years of actual, open, exclusive, hostile, and continuous possession. Payment of taxes is evidence of claim but not a statutory element for private land.

Boundary by acquiescence

A boundary established when adjoining owners mutually recognize and treat a line as the true boundary for at least 10 years, even if it differs from the deed record.

Riparian boundary rule

On non-navigable streams the boundary follows the thread of the stream; on navigable streams the state owns the bed and the boundary is the ordinary high water mark.

Iowa State Plane zones

Iowa uses two Lambert Conformal Conic zones: Iowa North (FIPS 1401) and Iowa South (FIPS 1402). Coordinates are in U.S. survey feet on NAD83.

Combined factor

Combined factor equals grid scale factor times elevation factor. Ground distance equals grid distance divided by the combined factor for reducing between grid and ground.

Elevation factor

Elevation factor = R / (R + H), where R is mean Earth radius at the latitude and H is ellipsoidal height. It reduces ground distances to the ellipsoid.

Geoid height relation

Orthometric height H equals ellipsoidal height h minus geoid height N. GEOID18 provides N for converting GNSS heights to NAVD88 elevations in Iowa.

Latitude and departure

Latitude equals distance times cosine of bearing; departure equals distance times sine of bearing. Sums around a closed traverse should equal zero before adjustment.

Linear misclosure

Linear misclosure is the square root of the sum of squared latitude and departure errors. Relative precision is misclosure divided by total traverse perimeter.

Compass rule adjustment

The compass (Bowditch) rule distributes traverse error proportionally to course length. The transit rule distributes error proportionally to latitude or departure magnitude instead.

Coordinate area formula

Area by coordinates uses 2A = sum of (Xi times Yi+1 minus Xi+1 times Yi). The double meridian distance method also computes area from adjusted latitudes and departures.

Horizontal curve formulas

Tangent T = R tan(Δ/2); length L = RΔ in radians; long chord LC = 2R sin(Δ/2); external E = R(sec(Δ/2) - 1); middle ordinate M = R(1 - cos(Δ/2)).

Degree of curve

Arc definition: D = 5729.578/R. Chord definition: D = 2 arcsin(50/R). Iowa DOT highway design uses the arc definition for horizontal curves.

PLSS township layout

A township is 6 miles square with 36 sections of one square mile each. Sections are numbered from 1 at the northeast corner, proceeding boustrophedon to 36 at the southeast.

Aliquot parts

Aliquot parts describe subdivisions of a section, such as the NE1/4 of the SW1/4, identifying a 40-acre tract. Government lots cover fractional areas near boundaries.

Meander corner

A meander corner is set where a survey line intersects the bank of a navigable water body. Meander lines follow the bank and are not boundary lines.

Proportionate measurement

Lost corners are reestablished by single or double proportionate measurement between accepted original corners, not by remeasuring record distances from a single point.

Iowa plat recording

Iowa Code Chapter 354 requires subdivision plats to be approved by the governing body before recording with the county recorder; Chapter 355 governs surveying practice.

Plat curve data

Subdivision plats show curve radius, arc length, central angle, tangent, and long chord. These values must be internally consistent when derived from the same radius and angle.

Floodplain mapping

The National Flood Hazard Layer and local ordinances under Iowa Code Chapter 455B regulate lots with base flood elevations. Check the effective FIRM panel before designing lots.

Construction staking check

Before staking, occupy a known control point and shoot another known monument to verify setup accuracy. A discrepancy indicates a setup or coordinate error.

Cut and fill stake

A cut stake indicates design grade is below existing ground; a fill stake indicates design grade is above. The difference between design and existing elevation gives the stake value.

Average end area volume

Volume by average end area equals length times the average of two cross-section areas. The prismoidal formula gives a more precise result for varying sections.

Iowa surveying board

The Iowa Engineering and Land Surveying Examining Board regulates licensure under Iowa Code Chapter 542B. Licensure requires education, experience, and NCEES and jurisprudence exams.

Seal and signature rule

A professional land surveyor must seal and sign plats, reports, and survey documents. Offering surveying services without a license is prohibited under Iowa law.

Continuing education

Iowa requires continuing education for license renewal. Surveyors should verify current hour and subject requirements with the examining board before each renewal cycle.

Conflict of interest

A surveyor must disclose any financial or personal interest that could bias a survey, and must avoid misrepresenting qualifications or accepting work outside competence.

Record retention

Board rules require surveyors to retain field notes, computations, and survey records. Copies may be required for clients, successors, or board inquiry.

NAD83 and NAVD88

NAD83 (2011) is the horizontal datum and NAVD88 the vertical datum used in Iowa. Legacy NAD27 and NGVD29 data require transformation before use.

GNSS static control

Static GNSS sessions should tie to at least two published control points or CORS for datum verification. Session length and satellite geometry affect achievable accuracy.

Iowa real-time network

The Iowa Real-Time Network (IaRTN) supplies RTK corrections. Surveyors should check residual accuracy and repeat observations before accepting derived coordinates.