Michael G. Wing

Airborne Light Detection and Ranging (LiDAR) for Individual Tree Stem Location, Height, and Biomass Measurements

Light Detection and Ranging (LiDAR) remote sensing has demonstrated potential in measuring forest biomass. We assessed the ability of LiDAR to accurately estimate forest total above ground biomass (TAGB) on an individual stem basis in a conifer forest in the US Pacific Northwest region using three different computer software programs and compared results to field measurements. Software programs included FUSION, TreeVaW, and watershed segmentation. To assess the accuracy of LiDAR TAGB estimation, stem counts and heights were analyzed. Differences between actual tree locations and LiDAR-derived tree locations using FUSION, TreeVaW, and watershed segmentation were 2.05 m (SD 1.67), 2.19 m (SD 1.83), and 2.31 m (SD 1.94), respectively, in forested plots. Tree height differences from field measured heights for FUSION, TreeVaW, and watershed segmentation were −0.09 m (SD 2.43), 0.28 m (SD 1.86), and 0.22 m (2.45) in forested plots; and 0.56 m (SD 1.07 m), 0.28 m (SD 1.69 m), and 1.17 m (SD 0.68 m), respectively, in a plot containing young conifers. The TAGB comparisons included feature totals per plot, mean biomass per feature by plot, and total biomass by plot for each extraction method. Overall, LiDAR TAGB estimations resulted in FUSION and TreeVaW underestimating by 25 and 31% respectively, and watershed segmentation overestimating by approximately 10%. LiDAR TAGB underestimation occurred in 66% and overestimation occurred in 34% of the plot comparisons.

Applying LiDAR technology for tree measurements in burned landscapes

Wildfires burn several million hectares in the United States annually. Time is critical in gathering information from burned landscapes for post-fire recovery planning. A technology to obtain spatial vegetation information across landscapes is Light Detecting and Ranging (LiDAR). We compared tree positional and height measurements, primarily from Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa), between field-based and LiDAR-derived measurements at three south-western Oregon (USA) sites. The sites represented a range of tree mortality from minimal to extensive. Our primary objective was to determine whether significant differences existed between field and LiDAR tree measurements in burned landscapes. Secondary objectives were to examine whether LiDAR pulse intensities in burned landscapes could differentiate coniferous from deciduous trees, discern fire-killed from live trees, and whether other tree measurement parameters were related to pulse intensities. No significant differences were detected between field-based and LiDAR-derived horizontal positions. Tree height differences between field-based and LiDAR measurements were significant at one site likely owing to dense canopy and measurement biases. Mean and maximum LiDAR intensities were significantly different between live and dead (fire-killed) trees in two of three sites. Additionally, crown diameter and tree sweep were significant in explaining variation in maximum LiDAR intensities at all sites.

A GIS-based decision support system for determining the shortest and safest route to forest fires: a case study in Mediterranean Region of Turkey

The ability of firefighting vehicles and staff to reach a fire area as quickly as possible is critical in fighting against forest fires. In this study, a Geographical Information System-based decision support system was developed to assist fire managers in determining the fastest and the safest or more reliable access routes from firefighting headquarters to fire areas. The decision support system was tested in the Kahramanmaras Forestry Regional Directoratein the Mediterranean region of Turkey. The study area consisted of forested lands which had been classified according to fire sensitivity. The fire response routing simulations considered firefighting teams located in 20 firefighting headquarter locations. The road network, the locations of the firefighting headquarters, and possible fire locations were mapped for simulation analysis. In alternative application simulations, inaccessible roads which might be closed due to fire or other reasons were indicated in the network analysis so that the optimum route was not only the fastest but also the safest and most reliable path. The selection of which firefighting headquarters to use was evaluated by considering critical response time to potential fire areas based on fire sensitivity levels. Results indicated that new firefighting headquarters should be established in the region in order to provide sufficient firefighting response to all forested lands. In addition, building new fire access roads and increasing the design speed on current roads could also increase firefighting response capabilities within the study area.

Applying geostatistics to quantify distributions of large woody debris in streams

Abstract Large woody debris (LWD) strongly influences morphology and aquatic habitat in streams within forested watersheds. Previous studies have used data to describe spatial distributions of LWD in qualitative terms. We used high-resolution spatial data collected from a forested stream in western Oregon to conduct three geostatistical analyses. The data were collected at five time periods prior to and following the addition of LWD into the stream. Each analysis is examined for its potential and shortcomings in quantifying distributions. Our findings indicate that semi-variograms, when used with a raster spatial data structure, can be useful quantitative descriptions of LWD distributions.

Estimating structural properties of riparian forests with airborne lidar data

Riparian forest zones adjacent to surface water such as streams, lakes, reservoirs and wetlands maintain significant forest ecosystem functions including nutrient cycling, vegetative communities, water quality, fish and wildlife habitat and landscape aesthetics. In order to support the sustainable management of riparian forests, riparian zones should first be carefully delineated and then structural properties of riparian vegetation, especially forest trees, should be accurately measured. Geographical information system (GIS) techniques have been previously implemented to determine riparian zones quickly and reliably. However, basic measurements of forest structures in riparian areas have relied heavily on field-based surveys, which can be extremely time consuming in large areas. In this study, riparian forest zones were initially located using GIS techniques and then airborne lidar (light detection and ranging) data were used to determine and analyse structural properties (i.e. tree height, crown diameter, canopy closure and vegetation density) of a sample riparian forest. Lidar-derived tree height and crown diameter measurements of sample trees were compared with field-based measurements. Results indicated that 77.92% of the riparian area in the study area was covered by forest. Based on lidar-derived data, the average tree height, total crown width, canopy closure (above 3 m) and vegetation density (3–15 m) were found to be 74.72 m, 16.82 m, 71.15% and 26.05%, respectively. Although we found differences between measurement methods, lidar-derived riparian tree measurements were highly correlated with field measurements for tree height (R 2 = 88%) and crown width (R 2 = 92%). Differences between measurement methods were likely a result of difficulties associated with field measurements in the dense vegetation that is often associated with forested riparian areas.

Applying airborne LiDAR for forested road geomatics

Airborne Light Detection and Ranging (LiDAR) has become a popular remote sensing technology to create digital terrain models and provide forest inventory information. However, little research has been done to investigate the accuracy of using scanning airborne LiDAR to perform road geomatics tasks common to forest engineering. We used airborne LiDAR to estimate existing forest road characteristics in support of a road assessment under four different canopy conditions. In estimating existing road centerlines, LiDAR data had a vertical root mean squared error (RMSE) of 0.28 m and a horizontal RMSE of 1.21 m. Road grades were estimated to within 1% slope of the value sampled in the field and horizontal curve radii were estimated with an average absolute error of 3.17 m. The results suggest that airborne LiDAR is an acceptable data source to estimate forest road centerlines and grades, but some caution should be used in estimating horizontal curve radii, particularly on sharp curves.

Developing a sustainable water-delivery system in rural El Salvador

Abstract Engineers Without Borders-USA (EWB-USA) consists of over 50 professional chapters throughout the country and over 100 student chapters at engineering universities. The goal of EWB-USA is to assist developing communities implement sustainable engineering projects that foster quality-of-life improvements while developing internationally responsible engineers and engineering students. An EWB-USA chapter at Oregon State University (EWB-OSU) has focused efforts on designing a sustainable water system to provide clean water for two communities in El Salvador. The communities are located in remote and mountainous terrain and have little available data describing local resources. The health of the communities has suffered due to a lack of clean drinking water. Small teams from the EWB-OSU chapter have now twice visited the communities to collect data using global positioning system (GPS) receivers. Financial support for travel costs has come from a variety of sources. The local community has helped field teams locate important resources and verify information to support the design process. Although considerable project progress has occurred, challenges have resulted from working in remote and rugged landscapes and also from land use and ownership considerations in the communities. We describe in this essay EWB-OSU activities to design and implement an engineering project to provide freshwater to rural communities in a remote, rural community.

Comparing Ecoregional Classifications for Natural Areas Management in the Klamath Region, USA

ABSTRACT: We compared three existing ecoregional classification schemes (Bailey, Omernik, and World Wildlife Fund) with two derived schemes (Omernik Revised and Climate Zones) to explore their effectiveness in explaining species distributions and to better understand natural resource geography in the Klamath Region, USA. We analyzed presence/absence data derived from digital distribution maps for trees, amphibians, large mammals, small mammals, migrant birds, and resident birds using three statistical analyses of classification accuracy (Analysis of Similarity, Canonical Analysis of Principal Coordinates, and Classification Strength). The classifications were roughly comparable in classification accuracy, with Omernik Revised showing the best overall performance. Trees showed the strongest fidelity to the classifications, and large mammals showed the weakest fidelity. We discuss the implications for regional biogeography and describe how intermediate resolution ecoregional classifications may be appropriate for use as natural areas management domains.

Differential GPS effectiveness in measuring area and perimeter in forested settings

This study quantifies area and perimeter measurement errors, traverse times, recording intervals, and overall time and cost effectiveness for using a mapping-grade differential Global Positioning System (GPS) receiver in forested settings. We compared two configurations including one that maximized data collection productivity (position dilution of precision (PDOP) 20, signal to noise ratio (SNR 33), and minimum elevation mask 5°) and a second that involved traditional receiver settings that was designed to improve accuracies (PDOP 6, SNR 39, and minimum elevation mask 15°). We determined that averaging 30 positions and using the settings that maximized productivity was the most time effective combination of recording interval and settings. This combination of recording interval and settings proved slightly more cost effective than other traditional surveying methods such as a laser with digital compass and string box. Average absolute per cent area errors when averaging 30 positions and using maximum settings were 2.6% and average absolute per cent perimeter errors were 2.0%. These results should help forest resource professionals more effectively evaluate GPS techniques and receiver configurations.

A low-cost near-infrared digital camera for fire detection and monitoring

ABSTRACT The human visualization system is not optimally suited for fire detection. Smoke occlusion heavily limits flame visibility and low flames can be difficult to see. Thermal infrared (TIR) sensors mitigate these effects but come at high costs (>