TOWARDS OBJECT-BASED EVALUATION OF INDIVIDUAL FIRES AT GLOBAL SCALES

Fire is a complex biophysical variable that has shaped the land surface for over 400 million years and continues to play important roles in landscape management, atmospheric emissions, and ecology. Our understanding of global fire patterns has improved dramatically in recent decades, coincident with the rise of systematic acquisition and development of global thematic products based on satellite remote sensing. Currently, there are several operational algorithms which map burned area, relying on coarse spatial resolution sensors with high temporal frequencies to identify fire-affected surfaces. While wildfires have been analyzed over large areas at the pixel level, object-based methods can provide more detailed attributes about individual fires such as fire size, severity, and spread rate. This dissertation evaluates burned area products using object-based methods to quantify errors in burn shapes and to extract individual fires from existing datasets. First, a wall-to-wall intercomparison of four publicly available burned area products highlights differences in the spatial and temporal patterns of burning identified by each product. The results of the intercomparison show that the MODIS Collection 6 MCD64A1 Burned Area product mapped the most burned area out of the four products, and all products except the Copernicus Burnt Area product showed agreement with regard to temporal burning patterns. In order to determine the fitness of the MCD64A1 product for mapping fire shapes, a framework for evaluating the shape accuracy of individual fires was developed using existing object-based metrics and a novel metric, the “edge error”. The object-based accuracy assessment demonstrated that MCD64A1 preserves the fire shape well compared to medium resolution data. Based on this result, an algorithm for extracting individual fires from MCD64A1 data was developed which improves upon existing algorithms through its use of an uncertainty-based approach rather than empirically driven approaches. The individual fires extracted by this algorithm were validated against medium resolution data in Canada and Alaska using object-based metrics, and the results indicate the algorithm provides an improvement over similar datasets. Overall, this dissertation demonstrates the capability of coarse resolution burned area products to accurately identify individual fire shapes and sizes. Recommendations for future work include improving the quality assessment of burned area products and continuing research into identifying spatiotemporal patterns in fire size distributions over large areas

Evaluation of hierarchical segmentation for natural vegetation: a case study of the Tehachapi Mountains, California

abstract: Two critical limitations for hyperspatial imagery are higher imagery variances and large data sizes. Although object-based analyses with a multi-scale framework for diverse object sizes are the solution, more data sources and large amounts of testing at high costs are required. In this study, I used tree density segmentation as the key element of a three-level hierarchical vegetation framework for reducing those costs, and a three-step procedure was used to evaluate its effects. A two-step procedure, which involved environmental stratifications and the random walker algorithm, was used for tree density segmentation. I determined whether variation in tone and texture could be reduced within environmental strata, and whether tree density segmentations could be labeled by species associations. At the final level, two tree density segmentations were partitioned into smaller subsets using eCognition in order to label individual species or tree stands in two test areas of two tree densities, and the Z values of Moran's I were used to evaluate whether imagery objects have different mean values from near segmentations as a measure of segmentation accuracy. The two-step procedure was able to delineating tree density segments and label species types robustly, compared to previous hierarchical frameworks. However, eCognition was not able to produce detailed, reasonable image objects with optimal scale parameters for species labeling. This hierarchical vegetation framework is applicable for fine-scale, time-series vegetation mapping to develop baseline data for evaluating climate change impacts on vegetation at low cost using widely available data and a personal laptop.Dissertation/ThesisM.A. Geography 201

Eligibility Testing at Three Prehistoric Sites at Lynch Creek, Lampasas County, Texas

In August 2004, archeologists from the Cultural Resources Section of the Planning, Permitting and Licensing Practice of TRC Environmental Corporation’s Austin office conducted National Register eligibility testing and geoarcheological documentation at three previously unrecorded prehistoric sites, 41LM49, 41LM50, and 41LM51, at two separate bridge crossings over Lynch Creek (TxDOT Project CSJ: #0231-15-032; designated East and West) by Farm to Market Road 580W (FM 580W) in western Lampasas County, Texas. This archeological investigation was necessary under the requirements of Section 106 of the National Historic Preservation Act (NHPA), the implementing regulations of 36CRF Part 800 and the Antiquities Code of Texas (Texas Natural Resource Code, Title 9, Chapter 191 as amended) to assess eligibility of all three cultural resource sites for listing on the National Register of Historic Places (NRHP) and for designation as a State Antiquities Landmark (SAL). This eligibility assessment was for the Texas Department of Transportation (TxDOT), Environmental Affairs Division under a Scientific Services Contract No. 573XXSA006 (Work Authorization No. 57315SA006). The analysis and reporting were conducted under contracts 575XXSA008 (Work Authorization 57510SA008), 577XXSA003 (Work Authorization No. 57704SA003) and 571XXSA003 (Work Authorization 57113SA003). All work was performed under Texas Antiquities Committee Permit No. 3494, issued by the Texas Historical Commission (THC) prior to the planned replacement of the two bridges. The materials, artifacts, records, and photographs will be curated at Texas Archeological Research Laboratory (TARL) in Austin

A ZooMS-informed archaeozoological and taphonomic analysis comparing Neanderthal and Homo sapiens subsistence behaviours in Northwest Italy

Ce projet contribue aux discussions en cours sur la transition du Paléolithique moyen au Paléolithique supérieur en Europe occidentale marquée par un tournant dans l’évolution de notre espèce, l’Homo sapiens. Alors que les Néandertaliens, nos plus proches cousins évolutionnaires disparaissent du registre fossile, les humains modernes qui ont migré hors d’Afrique, se dispersent rapidement à travers l’Eurasie. Les deux populations étaient exposées aux mêmes changements climatiques dramatiques caractéristiques de la transition, et pourtant, les Néandertaliens sont rapidement remplacés par les humains modernes. Par conséquent, ce phénomène suggère que les populations humaines modernes auraient pu être mieux adaptées face aux changements environnementaux. Puisque le régime alimentaire est un bon moniteur de l’adaptation, cette recherche compare les stratégies de subsistance des deux espèces humaines ayant tour à tour occupé le site de Riparo Bombrini (Balzi Rossi, Ligurie, Italie). Une analyse archéozoologique et taphonomique a été effectuée sur les collections fauniques du Moustérien tardif et du Proto-Aurignacien afin d’obtenir la première comparaison détaillée du régime alimentaire et des comportements de chasse des Néandertaliens et des humains modernes sur l’un des seuls sites du nord-ouest de l’Italie entièrement documenté avec des méthodes archéologiques modernes. Étant donné que la nature très fragmentée des ossements animaux sur le site a été un obstacle aux analyses fauniques dans le passé, les méthodes d’analyse archéozoologique ont été complétées par le « collagen fingerprinting » (c.-à-d. zooarchéologie par spectrométrie de masse, ou ZooMS) afin d’assurer l’identification d’un maximum de spécimens pour atteindre une précision accrue de l’identification taxonomique. La préservation différentielle du collagène dans les restes squelettiques a également justifié le développement d’une méthode novatrice de dépistage du collagène utilisant la spectroscopie FTIR-ATR pour la présélection d’échantillons ZooMS. Les résultats montrent que, tandis que Néandertal et Homo sapiens ont continuellement chassé les taxons ongulés disponibles à proximité de Riparo Bombrini, les niveaux de Moustérien tardif indiquent un rétrécissement du tableau de chasse associé à un mode de subsistance hyperlocal. En revanche, les spectres fauniques se sont considérablement élargis dans le plus ancien Proto-Aurignacien, lorsque Riparo Bombrini était occupé comme camp de base logistique à long terme associé à un vaste territoire de subsistance. Les résultats fournissent également les premières données détaillées sur la subsistance des populations humaines durant la transition dans la région de l’arc liguro-provençal, établissant ainsi de nouvelles hypothèses à tester dans de futurs travaux concernant la nature changeante de leurs écologies.This project contributes to the ongoing debates over the Middle-Upper Paleolithic transition in Western Europe, which marks a turning point in the evolution of our species, Homo sapiens. While Neanderthals, our closest evolutionary relatives, went extinct at that time, modern humans who had migrated out of Africa dispersed very rapidly across Eurasia. While both populations were exposed to the same dramatic climatic shifts at the time, it is only the Neanderthals that quickly disappeared from the archeological record, suggesting that modern human populations may have been better adapted to react to environmental changes than Neanderthals. Since diet is a good monitor of adaptation, this research compares the subsistence strategies of both human groups as they occupied, in quick succession, the site of Riparo Bombrini (Balzi Rossi, Liguria, Italy). An archeozoological and taphonomic analysis was conducted on Late Mousterian and Proto-Aurignacian faunal collections to produce the first direct comparison between Neanderthal and modern human diets and hunting strategies at one of the only sites in Northwest Italy entirely excavated using modern documentation methods. Because the highly fragmented nature of the animal bones at the site has hindered faunal analysis in the past, these approaches were complemented by collagen fingerprinting (i.e., Zooarcheology by Mass Spectrometry, or ZooMS) to identify as many specimens as possible as to species, thus yielding unprecedented accuracy in taxonomic identification. The challenging collagen preservation state also required developing a screening method using FTIR-ATR spectroscopy prior to ZooMS. The results show that, while Neanderthals and modern humans continuously hunted prime-aged ungulate taxa available in a close range of Riparo Bombrini, the Late Mousterian levels indicate a narrower diet associated with a hyper-local subsistence range. In contrast, the faunal spectra broadened noticeably in the earliest Proto-Aurignacian, when Riparo Bombrini was occupied as a long-term logistical base camp within an extensive land-use strategy. The results also provide the first high-resolution view of human subsistence during the transition in the Liguro-Provençal arc region and set up test hypotheses about the changing nature of hominin behavioural ecology that can be further tested in future work