The Combined Application of LiDAR, Aerial Photography and

Pictometric Tools for Sinkhole Delineation

Scott C. Alexander, Mina Rahimi Kazerooni, Erik Larson, Cody Bomberger, Brittany Greenwaldt,

and E. Calvin Alexander, Jr.

Dept. of Earth Sciences, University of Minnesota, 310 Pillsbury Dr SE, Minneapolis, MN 55455

The location of sinkholes in karst and silici-karst environments has taken on increasing importance

in land use planning and zoning regulations across South East and East Central Minnesota. The

delineation of sinkholes has traditionally depended on extensive field work, using topographic maps,

intensive networking with local landowners, and the luck of the observer to spot a feature that is

often rapidly filled or concealed within croplands.

The application of aerial tools now allows mappers to identify potential sinkholes and eliminate

holes generated by other surficial processes. LiDAR mapping across Minnesota now allows high

resolution imaging of very small depressions in Karst landscapes without interference from

vegetation. These depressions can then be compared to aerial photography flown periodically by the

USDA to verify persistence and/or reappearance of features through time. Additionally, low angle,

high resolution pictometric imagery allows overhead views from several angles to further identify

and verify the genesis of a given depression. While field verification is still the ultimate standard

many obvious sinkholes can be identified and numerous non-sinkhole depressions eliminated from

consideration greatly reducing field time.

Lidar and Pictometric view to the North. Circled areas to be field

checked. Possible sinks or may be related to older slumps.

SSlluummppss

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SSiinnkk##11 && SSiinnkk##22

PP..SS..##5566

PP..SS..##5577

Based on this Southward Pictometric view Sink#1 and #2 are

sinkholes. Possible sinks #56 and #57 need to be field checked.

Sink#2 & Sink#1

SSiinnkk##22 && SSiinnkk##11

PP..SS..##5577

PP..SS..##5566

Location in farmyard and rectangular shape of depression suggests

that it is an old building foundation.

Example of a sinkhole (D904) and a bull wallow.

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Possible sinkhole #4 is not visible on air photo, is not related to a

tile line and is minimally a closed depression. P.S. #4 is probably

not a sinkhole. However, many other sinks are visible in the

photo.

PPSS ##44

NNoo vviissiibbllee ssiinnkk

DD229977

DD229988

DD229966

DD88004477

DD880055

DD880066 DD880077

TTiillee LLiinnee

TTiillee LLiinnee

GGooooggllee EEaarrtthh iimmaaggee sshhoowwiinngg tthhee ssaammee aarreeaa wwiitthh

ttiillee lliinneess aanndd ssiinnkkss iinn AApprriill 11999911..

D295 D010

LLiiddaarr iimmaaggeerryy wwiitthh ssiinnkkhhoollee llooccaattiioonnss

D815 D816

D817

DD882288

((PPSS##77))

DD882299

((PPSS##88))

DD883300

((PPSS##99))

DD883311

((PPSS##1100))

DD883322

DD883333

DD883344

DD887788

PPSS##5544

PPSS##5533

DD552266

DD552277 DD887799

DD888800

DD888811

PPSS##4477

DD888822

PPSS##4488 DD888844

D901

PS#26

PS#25

D898

PS#28

D897

PS#38

D899

PS#29

D900

PS#27

D970

D971

D969 D821 D291

D822 D294