Range

NO. 68 DATE 05/17/04


Airborne LIDAR 

for Remediation 

of Abandoned 

Mine Lands 

By Russell Jackson, Photogrammetrist, 

BLM, National Science and 

Technology Center 

Introduction 

Acid mine drainage is a known 

concern in the upper Arkansas 

River near Leadville, Colorado. The 

Lake Fork tributary of the Arkansas 

River is 4 miles west of Leadville. 

This stream flows south out of 

Turquoise Lake for about 4 miles 

to its confluence with the Arkansas 

River. Below the Sugarloaf Dam 

on Turquoise Lake, many turn-ofthe-20th-century silver mines exist, 

with tailing piles leaching heavy 

metals into the Lake Fork tributary. 

To aid in the restoration of the Lake 

Fork watershed, high-resolution, 

highly accurate terrain data must 

be obtained. 

Traditionally, Bureau of Land 

Management (BLM) crews on the 

ground perform surveys of the site 

to capture the terrain data needed 

for the restoration process. Other 

technologies need to be evaluated 

that may provide the same accuracies and point density necessary 

for the remediation process. 

Although conventional photogrammetric practices can provide products that meet these requirements, 

recent advances with airborne Light 

Detection and Ranging (LIDAR) 

imaging systems may also satisfy 

the requirements in a more timely 

and efficient way than traditional 

photogrammetry. Products from 

both systems were evaluated in early 

2003, including bare-earth and vegetation models, digital orthoimages 

utilizing the terrain data during 

orthorectification, and intensity 

data generated from the LIDAR 

sensor in vegetation identification. 

Background 

Located between Leadville, Turquoise Lake, and the U.S. Fish 

and Wildlife Service Fish Hatchery, 

the Sugarloaf Gulch watershed has 

tremendous potential for public 

use. The watershed contains several 

wetland areas that could potentially 

be restored for valuable wildlife 

habitat. 

A detailed, three-dimensional map 

of the area would assist various 

projects that are under way or are 

planned in the Lake Fork watershed. The Lake Fork tributary and 

the surrounding wetlands are significantly affected by acidic mine 

drainage from the Sugarloaf Mining 

District. To create detailed threedimensional data, high-resolution, 

highly accurate elevation (terrain) 

data have been captured over the 

project area by LIDAR imaging 

systems and also from conventional 

aerial imagery. Although LIDAR 

technology may still be classified 

as an emerging technology, it has 

been used successfully in a variety 

of natural resource applications. 

Benefits 

The acquisition of elevation data 

will enable partnership institutions 

to evaluate several alternatives for 

Figure 1. LIDAR bare-earth x,y,z points draped over 

an orthoimage of the Dinero Dump. 

the reduction of acid drainage and 

to develop plans for engineering 

local drainage patterns that will 

alleviate potential recurrence of 

the problem. The primary benefit of work in this area will be an 

improvement of water quality in 

the Lake Fork tributary and the 

Arkansas River. 

LIDAR imaging can provide 

multiple spatial data sets, incluing 

digital elevation data, as digital 

elevation models (DEMs), ASCII 

x,y,z data points, and triangulated 

irregular networks (TINs), of 

the bare earth, canopy, and— 

potentially—the understory. In the 

present study, two elevation surfaces 

were acquired, the bare earth and 

the canopy (Figure 1), in ASCII 

x,y,z data format. An intensity 

model of the area was developed, 

and a digital orthoimage was created 

by the digital aerial camera located 

on the same aircraft platform flying 

the LIDAR system. These products 

were delivered within 30 days of 

the acquisition date. In addition 

to the LIDAR data, conventional 

aerial imagery was acquired to 

evaluate the accuracy and image 

quality (intensity) of the LIDAR. 

Digital elevation models and 

digital orthoimages were created 

for evaluating the LIDAR data. 

Conventional film of sufficient 

scale and quality, when combined 

with the geodetic survey control, 

provides more accurate products 

than the LIDAR, allowing BLM 

National Science and Technology 

Center scientists to evaluate the 

accuracy and quality of the LIDAR 

products. The products generated 

from the conventional film cannot 

be created as quickly as the 30-day 

delivery provided by LIDAR. The 

timeliness of LIDAR products is 

one of LIDAR’s greatest benefits. 

For resource management issues, 

LIDAR technology can provide 

Cartography/mapping sciences 

Resource Note 68 

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highly accurate products in a much 

shorter time than conventional 

mapping processes. 

Feasibility 

The LIDAR systems provide 

terrain data at the accuracies 

needed for this study (15–20 cm 

RMSEz vertical accuracy over the 

mine dump areas and 30–45 cm 

RMSEz accuracy over the rest of 

the watershed). LIDAR systems 

can produce accurate terrain 

data in areas of heavy vegetation 

cover faster and at a lower cost 

than traditional photogrammetric 

methods, which is significant in 

this study area because the overall 

site is covered with a fairly dense 

canopy of lodgepole pine and 

heavily vegetated riparian areas. In 

addition, a significant enhancement 

capability of LIDAR systems is the 

ability to generate surface models 

of the vegetation canopy from 

the same data sets that produce 

the bare-earth surface models. 

This additional surface model will 

provide information on the type 

and density of vegetation in the site 

for remediation and in support of 

other resource management issues 

such as wildfire management. 

The Bureau of Land Management Resource Notes, 


which are posted on this Web site 


(http://www.blm.gov/nstc/resourcenotes/resnotes.html),


are early announcements of technical and informational 


topics for BLM personnel and their customers. Informa-


tion contained in this Resource Note has not been 


peer-reviewed. Conclusions and opinions expressed herein 


do not necessarily represent those of BLM. Use of trade 


names does not imply U.S. government endorsement of 


commercial products.


Technical Editor - Deborah Harris 


(Debbie_Harris@blm.gov)


Science Editor - Brian St. George 


(Brian_St_George@blm.gov)


Graphic Designer - Ethel Coontz (Ethel_Coontz@blm.gov)


If you would like to prepare a Resource Note for 


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suggest an author for a Resource Note, contact 


the Science Editor (e-mail: Brian_St_George@blm.gov; 


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Thank you for your interest in Resource Notes.


Figure 2. Oblique view of the Dinero Dump showing 

an orthoimage draped over a surface model composed of 

bare-earth and canopy points. 

To understand the capabilities 

and accuracies associated with the 

LIDAR data, bare-earth surface 

models were created from the 

airborne imagery through photogrammetric methods and evaluated 

against the LIDAR bare-earth surface models. Costs associated with 

generating similar products have 

been evaluated and compared and 

are available on request. 

Although the overall cost of 

acquiring the LIDAR products is 

presently higher than the cost of 

products obtained from conventional photogrammetry, the future 

cost of photogrammetric work will 

exceed that of LIDAR. Total photogrammetric costs are presently 94% 

of the total LIDAR costs. Costs of 

the LIDAR products were $6.40 

per acre. Photogrammetric costs are 

$6.00 per acre. It should be noted 

that these costs are for this study 

only and should not be used to 

project costs of other studies. The 

photogrammetric products cover 

only the Dinero Dump (Figure 2; 

two stereo models), whereas the 

LIDAR products cover the entire 

project area. In addition to the 

costs for photogrammetric products, costs associated with reclaiming the dumps, producing volume 

calculations and cut–fill estimates, 

and additional survey costs for each 

dump must be considered. 

Conclusions 

The results of this project met the 

following objectives: 

• 	All the LIDAR data sets provided complete coverage in 

the project area. Only minor 

artifacts were noticeable in the 

digital orthoimage. 

• 	 All the products met the spatial 

requirements for the project. 

Horizontal accuracies according to the National Standard 

for Spatial Data Accuracy 

(NSSDA) 95% confidence level 

were equal to 1.11 meters at 

ground scale. Vertical accuracies 

at the NSSDA 95% confidence 

level were equal to 0.325 meters 

at ground scale. 

•	 All the data were delivered 

according to the specifications 

of the statement of work and 

delivered to the field office staff 

in the specified time. 

• 	 Costs associated with acquiring 

the LIDAR data sets were competitive with costs of products 

from conventional photogrammetric methods. 

Partnership institutions presently 

involved with research projects in 

the Lake Fork, Colorado, drainage are the University of Colorado, Colorado State University, 

Mesa State University (Colorado), 

Colorado Mountain College, Colorado School of Mines, U.S. Forest 

Service, U.S. Fish and Wildlife 

Service, U.S. Geological Survey, 

Colorado Division of Wildlife, and 

Lake County, Colorado. 

Contact 

Russell Jackson, Photogrammetrist 

National Science and 

Technology Center 

Denver Federal Center, 

Building 50 

Denver, CO 80225-0047 

Phone: 303-236-1614 

Fax: 303-236-6564 

Email: Russell_Jackson@blm.gov 

Resource Note 68 

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