Open Access. Powered by Scholars. Published by Universities.®

Physical and Environmental Geography Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 71

Full-Text Articles in Physical and Environmental Geography

Demonstration Of Large Area Land Cover Classification With A One Dimensional Convolutional Neural Network Applied To Single Pixel Temporal Metric Percentiles, Hankui K. Zhang, David P. Roy, Dong Luo Sep 2023

Demonstration Of Large Area Land Cover Classification With A One Dimensional Convolutional Neural Network Applied To Single Pixel Temporal Metric Percentiles, Hankui K. Zhang, David P. Roy, Dong Luo

GSCE Faculty Publications

Over large areas, land cover classification has conventionally been undertaken using satellite time series. Typically temporal metric percentiles derived from single pixel location time series have been used to take advantage of spectral differences among land cover classes over time and to minimize the impact of missing observations. Deep convolutional neural networks (CNNs) have demonstrated potential for land cover classification of single date images. However, over large areas and using time series their application is complicated because they are sensitive to missing observations and they may misclassify small and spatially fragmented surface features due to their spatial patch-based implementation. This …


Fire Emissions In The Tropical Indonesia: Improved Estimation And Driving Forces Investigation, Xiaoman Lu Jan 2022

Fire Emissions In The Tropical Indonesia: Improved Estimation And Driving Forces Investigation, Xiaoman Lu

Electronic Theses and Dissertations

Indonesia has experienced frequent fires since the 1970s due to large-scale peatland conversion and extensive drainage for agricultural development. Fire emissions released from these fires have led to Indonesia being the world’s 3rd largest emitter of greenhouse gases in certain years. Given that fire emissions severely affect climate, weather, and the human environment, numerous approaches have been developed to estimate fire emissions. However, existing emission estimates differ largely by a factor of four in this tropical country because of frequent cloud interferences and low-temperature smoldering fires. Therefore, this dissertation aims to improve the quantification of Indonesian fire emissions through enhanced …


Using New And Long-Term Multi-Scale Remotely Sensed Data To Detect Recurrent Fires And Quantify Their Relationship To Land Cover/Use In Indonesian Peatlands, Yenni Vetrita Jan 2021

Using New And Long-Term Multi-Scale Remotely Sensed Data To Detect Recurrent Fires And Quantify Their Relationship To Land Cover/Use In Indonesian Peatlands, Yenni Vetrita

Electronic Theses and Dissertations

Indonesia has committed to reducing its greenhouse gases emissions by 29% (potentially up to 41% with international assistance) by 2030. Achieving those targets requires many efforts but, in particular, controlling the fire problem in Indonesia’s peatlands is paramount, since it is unlikely to diminish on its own in the coming decades. This study was conducted in Sumatra and Kalimantan peatlands in Indonesia. Four MODIS-derived products (MCD45A1 collection 5.1, MCD64A1 (collection 5.1 and 6), FireCCI51) were initially assessed to explore long-term fire frequency and land use/cover change relationships. The results indicated the product(s) could only detect half of the fires accurately. …


Use And Improvement Of Remote Sensing And Geospatial Technologies In Support Of Crop Area And Yield Estimations In The West African Sahel, Kaboro Samasse Jan 2021

Use And Improvement Of Remote Sensing And Geospatial Technologies In Support Of Crop Area And Yield Estimations In The West African Sahel, Kaboro Samasse

Electronic Theses and Dissertations

In arid and semi-arid West Africa, agricultural production and regional food security depend largely on small-scale subsistence farming and rainfed crops, both of which are vulnerable to climate variability and drought. Efforts made to improve crop monitoring and our ability to estimate crop production (areas planted and yield estimations by crop type) in the major agricultural zones of the region are critical paths for minimizing climate risks and to support food security planning. The main objective of this dissertation research was to contribute to these efforts using remote sensing technologies. In this regard, the first analysis documented the low reliability …


How Much Variation In Land Surface Phenology Can Climate Oscillation Modes Explain At The Scale Of Mountain Pastures In Kyrgyzstan?, Monika A. Tomaszewska, Geoffrey M. Henebry May 2020

How Much Variation In Land Surface Phenology Can Climate Oscillation Modes Explain At The Scale Of Mountain Pastures In Kyrgyzstan?, Monika A. Tomaszewska, Geoffrey M. Henebry

NASA Land-Cover Land-Use Change Data Sets

Climate oscillation modes can shape weather across the globe due to atmospheric teleconnections. We built on the findings of a recent study to assess whether the impacts of teleconnections are detectable and significant in the early season dynamics of highland pastures across five rayons in Kyrgyzstan. Specifically, since land surface phenology (LSP) has already shown to be influenced by snow cover seasonality and terrain, we investigated here how much more explanatory and predictive power information about climatic oscillation modes might add to explain variation in LSP. We focused on seasonal values of five climate oscillation indices that influence vegetation dynamics …


Land Surface Phenology In The Highland Pastures Of Montane Central Asia: Interactions With Snow Cover Seasonality And Terrain Characteristics, Monika A. Tomaszewska, Lan H. Nguyen, Geoffrey Henebry Apr 2020

Land Surface Phenology In The Highland Pastures Of Montane Central Asia: Interactions With Snow Cover Seasonality And Terrain Characteristics, Monika A. Tomaszewska, Lan H. Nguyen, Geoffrey Henebry

NASA Land-Cover Land-Use Change Data Sets

Many studies have shown that high elevation environments are among very sensitive to climatic changes and where impacts are exacerbated. Across Central Asia, which is especially vulnerable to climate change due to aridity, the ability of global climate projections to capture the complex dynamics of mountainous environments is particularly limited. Over montane Central Asia, agropastoralism constitutes a major portion of the rural economy. Extensive herbaceous vegetation forms the basis of rural economies in Kyrgyzstan. Here we focus on snow cover seasonality and the effects of terrain on phenology in highland pastures using remote sensing data for 2001–2017. First, we describe …


Responses Of Land Surface Phenology To Wildfire Disturbances In The Western United States Forests, Jianmin Wang Jan 2020

Responses Of Land Surface Phenology To Wildfire Disturbances In The Western United States Forests, Jianmin Wang

Electronic Theses and Dissertations

Land surface phenology (LSP) characterizes the seasonal dynamics in the vegetation communities observed for a satellite pixel and it has been widely associated with global climate change. However, LSP and its long-term trend can be influenced by land disturbance events, which could greatly interrupt the LSP responses to climate change. Wildfire is one of the main disturbance agents in the western United States (US) forests, but its impacts on LSP have not been investigated yet. To gain a comprehensive understanding of the LSP responses to wildfires in the western US forests, this dissertation focused on three research objectives: (1) to …


Characterizing Spatiotemporal Patterns Of White Mold In Soybean Across South Dakota Using Remote Sensing, Confiance L. Mfuka Jan 2019

Characterizing Spatiotemporal Patterns Of White Mold In Soybean Across South Dakota Using Remote Sensing, Confiance L. Mfuka

Electronic Theses and Dissertations

Soybean is among the most important crops, cultivated primarily for beans, which are used for food, feed, and biofuel. According to FAO, the United States was the biggest soybeans producer in 2016. The main soybean producing regions in the United States are the Corn Belt and the lower Mississippi Valley. Despite its importance, soybean production is reduced by several diseases, among which Sclerotinia stem rot, also known as white mold, a fungal disease that is caused by the fungus Sclerotinia sclerotiorum is among the top 10 soybean diseases. The disease may attack several plants and considerably reduce yield. According to …


Augmenting Land Cover/Land Use Classification By Incorporating Information From Land Surface Phenology: An Application To Quantify Recent Cropland Expansion In South Dakota, Lan Hoang Nguyen Jan 2019

Augmenting Land Cover/Land Use Classification By Incorporating Information From Land Surface Phenology: An Application To Quantify Recent Cropland Expansion In South Dakota, Lan Hoang Nguyen

Electronic Theses and Dissertations

Understanding rapid land change in the U.S. NGP region is not only critical for management and conservation of prairie habitats and ecosystem services, but also for projecting production of crops and biofuels and the impacts of land conversion on water quality and rural transportation infrastructure. Hence, it raises the need for an LCLU dataset with good spatiotemporal coverage as well as consistent accuracy through time to enable change analysis. This dissertation aims (1) to develop a novel classification method, which utilizes time series images from comparable sensors, from the perspective of land surface phenology, and (2) to apply the land …


Land Cover Changes Within And Around Protected Areas In Côte D’Ivoire From 1986 To 2017: A Case Study Of The Mabi-Yaya-Songan-Tamin Reserved Forests, Olena Boiko Jan 2019

Land Cover Changes Within And Around Protected Areas In Côte D’Ivoire From 1986 To 2017: A Case Study Of The Mabi-Yaya-Songan-Tamin Reserved Forests, Olena Boiko

Electronic Theses and Dissertations

Tropical forests mitigate climate change, provide habitat for the most biologically diverse terrestrial communities, and yield ecosystem services that support human wellbeing. These forests are some of the most threatened ecosystems because of the increasing human impact on the environment. Côte d’Ivoire has one of the highest deforestation rates in sub-Saharan Africa, and the expansion of agriculture to produce cash crops, such as cocoa and rubber, is presented as the primary reason for forest loss. These changes are apparent even within the boundaries of the protected areas, which raises concerns about the effectiveness of the protection strategies. This project illustrates …


Tropical Forest Canopy Height And Aboveground Biomass Estimation Using Airborne Lidar And Landsat-8 Data, A Sensitivity Study With Respect To Landsat-8 Data Temporal Availability, In Mai Ndombe Province, Democratic Republic Of Congo, Herve B. Kashongwe Jan 2019

Tropical Forest Canopy Height And Aboveground Biomass Estimation Using Airborne Lidar And Landsat-8 Data, A Sensitivity Study With Respect To Landsat-8 Data Temporal Availability, In Mai Ndombe Province, Democratic Republic Of Congo, Herve B. Kashongwe

Electronic Theses and Dissertations

Tropical forests’ structure information, such as forest canopy height, is a key component in any estimate of carbon stock. Tropical rainforests constitute the most forested ecosystems that harbor the largest biodiversity on Earth and store more carbon (above and belowground biomass) than any other ecosystem in the world. However, estimates of forest canopy structure is lacking over most of the regions that host this ecosystem because of both the structure’s complexity of this ecosystems and the incomplete or lack of up-to-date national forest inventory data necessary to derive forest canopy height and aboveground biomass. This study explores the capability of …


How Are Interannual Variations Of Land Surface Phenology In The Highland Pastures Of Kyrgyzstan Modulated By Terrain, Snow Cover Seasonality, And Climate Oscillations? An Investigation Using Multi-Source Remote Sensing Data, Monika Anna Tomaszewska Jan 2019

How Are Interannual Variations Of Land Surface Phenology In The Highland Pastures Of Kyrgyzstan Modulated By Terrain, Snow Cover Seasonality, And Climate Oscillations? An Investigation Using Multi-Source Remote Sensing Data, Monika Anna Tomaszewska

Electronic Theses and Dissertations

In the semiarid, continental climates of montane Central Asia, with its constant moisture deficit and low relative humidity, agropastoralism constitutes the foundation of the rural economy. In Kyrgyzstan, an impoverished, landlocked republic in Central Asia, herders of the highlands practice vertical transhumance—the annual movement of livestock to higher elevation pastures to take advantage of seasonally available forage resources. Dependency on pasture resource availability during the short mountain growing season makes herds and herders susceptible to changing weather and climate patterns. This dissertation focuses on using remote sensing observations over the highland pastures in Kyrgyzstan to address five interrelated topics: (i) …


Classification Of North Africa For Use As An Extended Pseudo Invariant Calibration Sites (Epics) For Radiometric Calibration And Stability Monitoring Of Optical Satellite Sensors, Mahesh Shrestha Jan 2019

Classification Of North Africa For Use As An Extended Pseudo Invariant Calibration Sites (Epics) For Radiometric Calibration And Stability Monitoring Of Optical Satellite Sensors, Mahesh Shrestha

Electronic Theses and Dissertations

An increasing number of Earth-observing satellite sensors are being launched to meet the insatiable demand for timely and accurate data to help the understanding of the Earth’s complex systems and to monitor significant changes to them. The quality of data recorded by these sensors is a primary concern, as it critically depends on accurate radiometric calibration for each sensor. Pseudo Invariant Calibration Sites (PICS) have been extensively used for radiometric calibration and temporal stability monitoring of optical satellite sensors. Due to limited knowledge about the radiometric stability of North Africa, only a limited number of sites in the region are …


Large Scale Climate Oscillation Impacts On Temperature, Precipitation And Land Surface Phenology In Central Asia, Kirsten M. De Beurs, Geoffrey Henebry, Braden C. Owsley, Irina N. Sokolik Jun 2018

Large Scale Climate Oscillation Impacts On Temperature, Precipitation And Land Surface Phenology In Central Asia, Kirsten M. De Beurs, Geoffrey Henebry, Braden C. Owsley, Irina N. Sokolik

GSCE Faculty Publications

Central Asia has been rapidly changing in multiple ways over the past few decades. Increases in temperature and likely decreases in precipitation in Central Asia as the result of global climate change are making one of the most arid regions in the world even more susceptible to large-scale droughts. Global climate oscillations, such as the El Ni ̃no–Southern Oscillation, have previously been linked to observed weather patterns in Central Asia. However, until now it has been unclear how the different climate oscillations act simultaneously to affect the weather and subsequently the vegetated land surface in Central Asia.We fit well-established land …


Changing Snow Seasonality In The Highlands Of Kyrgyzstan, Monika Tomaszewska, Geoffrey Henebry May 2018

Changing Snow Seasonality In The Highlands Of Kyrgyzstan, Monika Tomaszewska, Geoffrey Henebry

GSCE Faculty Publications

Few studies have examined changing snow seasonality in Central Asia. Here, we analyzed changes in the seasonality of snow cover across Kyrgyzstan (KGZ) over 14 years from 2002/03–2015/16 using the most recent version (v006) of MODIS Terra and Aqua 8 day snow cover composites (MOD10A2/MYD10A2). We focused on three metrics of snow seasonality—first date of snow, last date of snow, and duration of snow season—and used nonparametric trends tests to assess the significance and direction of trends. We evaluated trends at three administration scales and across elevation. We used two techniques to assure that our identification of significant trends was …


Changing Snow Seasonality In The Highlands Of Kyrgyzstan, Monika Tomaszewska, Geoffrey Henebry May 2018

Changing Snow Seasonality In The Highlands Of Kyrgyzstan, Monika Tomaszewska, Geoffrey Henebry

NASA Land-Cover Land-Use Change Data Sets

Few studies have examined changing snow seasonality in Central Asia. Here, we analyzed changes in the seasonality of snow cover across Kyrgyzstan (KGZ) over 14 years from 2002/03–2015/16 using the most recent version (v006) of MODIS Terra and Aqua 8 day snow cover composites (MOD10A2/MYD10A2).We focused on three metrics of snow seasonality—first date of snow, last date of snow, and duration of snow season—and used nonparametric trends tests to assess the significance and direction of trends. We evaluated trends at three administration scales and across elevation. We used two techniques to assure that our identification of significant trends was not …


Quantifying Undisturbed (Native) Lands In Northwestern South Dakota: 2013, Pete Bauman, Benjamin Carlson, Tanner Butler, Brad Richardson Jan 2018

Quantifying Undisturbed (Native) Lands In Northwestern South Dakota: 2013, Pete Bauman, Benjamin Carlson, Tanner Butler, Brad Richardson

Quantifying Undisturbed (Native) Lands in Northwestern South Dakota: 2013

We employed simple GIS methods primarily utilizing the South Dakota Farm Service Agency’s Common Land Unit (CLU) data layers from 2013 and the 2012 United States Department of Agriculture (USDA) National Agriculture Imagery Program (NAIP) county mosaic aerial imagery to evaluate 7,347,812 acres of land in northwestern South Dakota. The analysis area includes: Harding, Perkins, and Butte counties along with portions of Lawrence and Meade counties outside of the Black Hills Core Highlands and Plateau Ecoregions.

We utilized the FSA CLU data layer queried to show current and former cropland to identify and remove any areas with cropping history regardless …


Expansion Of Major Urban Areas In The Us Great Plains From 2000 To 2009 Using Satellite Scatterometer Data, Lan H. Nguyen, Son V. Nghiem, Geoffrey M. Henebry Jan 2018

Expansion Of Major Urban Areas In The Us Great Plains From 2000 To 2009 Using Satellite Scatterometer Data, Lan H. Nguyen, Son V. Nghiem, Geoffrey M. Henebry

GSCE Faculty Publications

A consistent dataset delineating and characterizing changes in urban environments will be valuable for socioeconomic and environmental research and for sustainable urban development. Remotely sensed data have been long used to map urban extent and infrastructure at various spatial and spectral resolutions. Although many datasets and approaches have been tried, there is not yet a universal way to map urban extents across the world. Here we combined a microwave scatterometer (QuikSCAT) dataset at ~1 km posting with percent impervious surface area (%ISA) data from the National Land Cover Dataset (NLCD) that was generated from Landsat data, and ambient population data …


Vulnerability Of Protected Areas To Human Encroachment, Climate Change And Fire In The Fragmented Tropical Forests Of West Africa, Francis Kwabena Dwomoh Jan 2018

Vulnerability Of Protected Areas To Human Encroachment, Climate Change And Fire In The Fragmented Tropical Forests Of West Africa, Francis Kwabena Dwomoh

Electronic Theses and Dissertations

The Upper Guinean region of West Africa is home to some of the most globally significant tropical biodiversity hotspots, providing ecosystem services that are crucial for the region’s socio-economic and environmental wellbeing. Nonetheless, following decades of human-caused destruction of natural habitats, protected areas currently remain the only significant refugia of original vegetation relics in landscapes that are highly fragmented. Aside from having strong geographic variation in land use, climate, vegetation, and human population, the region has also experienced remarkable biophysical and socio-economic changes in recent decades. All these factors influence the fire regime and the vulnerability of forests within protected …


Satellite Remote Sensing Of Woody And Herbaceous Leaf Area For Improved Understanding Of Forage Resources And Fire In Africa, Milkah Njoki Kahiu Jan 2018

Satellite Remote Sensing Of Woody And Herbaceous Leaf Area For Improved Understanding Of Forage Resources And Fire In Africa, Milkah Njoki Kahiu

Electronic Theses and Dissertations

In sub-Saharan Africa (SSA) tree-grass systems commonly referred to as savannas dominating drylands, play a critical role in social, cultural, economic and environmental systems. These coupled natural-human systems support millions of people through pastoralism, are important global biodiversity hotspots and play a critical role in global biogeochemical cycles. Despite the importance of SSA savannas, they have been marginalized for years as most governments neglect dryland resources in favor of agricultural research and development assistance. Hence, lack of spatially and temporally accurate information on the status and trends in savanna resources has led to poor planning and management. This scenario calls …


A Study Of African Savanna Vegetation Structure, Patterning, And Change, Christoffer R. Axelsson Jan 2018

A Study Of African Savanna Vegetation Structure, Patterning, And Change, Christoffer R. Axelsson

Electronic Theses and Dissertations

African savannas cover roughly half of the continent, are home to a great diversity of wildlife, and provide ecosystem services to large populations. Savannas showcase a great diversity in vegetation structure, resulting from variation in climatic, edaphic, topographic, and biological factors. Fires play a large role as savannas are the most frequently burned ecosystems on Earth. To study how savanna vegetation structure shifts with environmental factors, it is necessary to gather site data covering the full gradient of climatic and edaphic conditions. Several earlier studies have used coarse resolution satellite remote sensing data to study variation in woody cover. These …


Mapping And Risk Assessment Of Juniper Encroachment Into A Prairie Landscape, Kyle D. Kaskie Jan 2018

Mapping And Risk Assessment Of Juniper Encroachment Into A Prairie Landscape, Kyle D. Kaskie

Electronic Theses and Dissertations

Juniper encroachment is a considerable threat to the prairie ecosystems of the Great Plains because it has the potential to alter native grasslands by changing soil characteristics, limiting herbaceous biomass, and hindering native community regeneration. Accurate maps of juniper cover and predictions of areas at risk for future expansion are needed to support proactive management measures. Therefore, our objectives are to: (1) Develop a practical workflow for large-scale juniper mapping using Landsat 8 Operational Land Imager (OLI) imagery and partial unmixing techniques, (2) Compare the classification accuracies from the resulting map based on different juniper density thresholds and different types …


Northern Eurasia Future Initiative (Nefi): Facing The Challenges And Pathways Of Global Change In The Twenty-First Century, Pavel Groisman, Herman Shugart, David Kicklighter, Geoffrey Henebry, Nadezhda Tchebakova, Shamil Maksyutov, Erwan Monier, Garik Gutman, Sergey Gulev, Jiaguo Qi, Alexander Prishchepov, Elena Kukavskaya, Boris Porfiriev, Alexander Shiklomanov, Tatiana Loboda, Nikolay Shiklomanov, Son Nghiem, Kathleen Bergen, Jana Albrechtová, Jiquan Chen, Maria Shahgedanova, Anatoly Shvidenko, Nina Speranskaya, Amber Soja, Kirsten De Beurs, Olga Bulygina, Jessica Mccarty, Qianlai Zhuang, Olga Zolina Dec 2017

Northern Eurasia Future Initiative (Nefi): Facing The Challenges And Pathways Of Global Change In The Twenty-First Century, Pavel Groisman, Herman Shugart, David Kicklighter, Geoffrey Henebry, Nadezhda Tchebakova, Shamil Maksyutov, Erwan Monier, Garik Gutman, Sergey Gulev, Jiaguo Qi, Alexander Prishchepov, Elena Kukavskaya, Boris Porfiriev, Alexander Shiklomanov, Tatiana Loboda, Nikolay Shiklomanov, Son Nghiem, Kathleen Bergen, Jana Albrechtová, Jiquan Chen, Maria Shahgedanova, Anatoly Shvidenko, Nina Speranskaya, Amber Soja, Kirsten De Beurs, Olga Bulygina, Jessica Mccarty, Qianlai Zhuang, Olga Zolina

GSCE Faculty Publications

During the past several decades, the Earth system has changed significantly, especially across Northern Eurasia. Changes in the socio-economic conditions of the larger countries in the region have also resulted in a variety of regional environmental changes that can have global consequences. The Northern Eurasia Future Initiative (NEFI) has been designed as an essential continuation of the Northern Eurasia Earth Science Partnership Initiative (NEESPI), which was launched in 2004. NEESPI sought to elucidate all aspects of ongoing environmental change, to inform societies and, thus, to better prepare societies for future developments. A key principle of NEFI is that these developments …


Examination Of Sentinel-2a Multi-Spectral Instrument (Msi) Reflectance Anisotropy And The Suitability Of A General Method To Normalize Msi Reflectance To Nadir Brdf Adjusted Reflectance, David P. Roy, Jian Li, Hankui Zhang, Lin Yan Dr., Haiyan Huang, Zhongbin Li Sep 2017

Examination Of Sentinel-2a Multi-Spectral Instrument (Msi) Reflectance Anisotropy And The Suitability Of A General Method To Normalize Msi Reflectance To Nadir Brdf Adjusted Reflectance, David P. Roy, Jian Li, Hankui Zhang, Lin Yan Dr., Haiyan Huang, Zhongbin Li

GSCE Faculty Publications

The Sentinel-2A multi-spectral instrument (MSI) acquires multi-spectral reflective wavelength observations with directional effects due to surface reflectance anisotropy and changes in the solar and viewing geometry. Directional effects were examined by considering two ten day periods of Sentinel-2A data acquired close to the solar principal and orthogonal planes over approximately 20° × 10° of southern Africa. More than 6.6 million (January 2016) and 10.6 million (April 2016) pairs of reflectance observations sensed 3 or 7 days apart in the forward and backscatter directions in overlapping Sentinel-2A orbit swaths were considered. The Sentinel-2A data were projected into the MODIS sinusoidal projection …


Land Surface Phenology And Seasonality Using Cool Earthlight In Croplands Of Eastern Africa And The Linkages To Crop Production, Woubet G. Alemu, Geoffrey M. Henebry Sep 2017

Land Surface Phenology And Seasonality Using Cool Earthlight In Croplands Of Eastern Africa And The Linkages To Crop Production, Woubet G. Alemu, Geoffrey M. Henebry

GSCE Faculty Publications

Across Eastern Africa, croplands cover 45 million ha. The regional economy is heavily dependent on small holder traditional rain-fed peasant agriculture (up to 90%), which is vulnerable to extreme weather events such as drought and floods that leads to food insecurity. Agricultural production in the region is moisture limited. Weather station data are scarce and access is limited, while optical satellite data are obscured by heavy clouds limiting their value to study cropland dynamics. Here, we characterized cropland dynamics in Eastern Africa for 2003–2015 using precipitation data from Tropical Rainfall Measuring Mission (TRMM) and a passive microwave dataset of land …


Using The 500 M Modis Land Cover Product To Derive A Consistent Continental Scale 30 M Landsat Land Cover Classification, Hankui Zhang, David P. Roy Aug 2017

Using The 500 M Modis Land Cover Product To Derive A Consistent Continental Scale 30 M Landsat Land Cover Classification, Hankui Zhang, David P. Roy

GSCE Faculty Publications

Classification is a fundamental process in remote sensing used to relate pixel values to land cover classes present on the surface. Over large areas land cover classification is challenging particularly due to the cost and difficulty of collecting representative training data that enable classifiers to be consistent and locally reliable. A novel methodology to classify large volume Landsat data using high quality training data derived from the 500 m MODIS land cover product is demonstrated and used to generate a 30 m land cover classification for all of North America between 20°N and 50°N. Publically available 30 m global monthly …


A Global Analysis Of Sentinel-2a, Sentinel-2b And Landsat-8 Data Revisit Intervals And Implications For Terrestrial Monitoring, Jian Li, David P. Roy Aug 2017

A Global Analysis Of Sentinel-2a, Sentinel-2b And Landsat-8 Data Revisit Intervals And Implications For Terrestrial Monitoring, Jian Li, David P. Roy

GSCE Faculty Publications

Combination of different satellite data will provide increased opportunities for more frequent cloud-free surface observations due to variable cloud cover at the different satellite overpass times and dates. Satellite data from the polar-orbiting Landsat-8 (launched 2013), Sentinel-2A (launched 2015) and Sentinel-2B (launched 2017) sensors offer 10 m to 30 m multi-spectral global coverage. Together, they advance the virtual constellation paradigm for mid-resolution land imaging. In this study, a global analysis of Landsat-8, Sentinel-2A and Sentinel-2B metadata obtained from the committee on Earth Observation Satellite (CEOS) Visualization Environment (COVE) tool for 2016 is presented. A global equal area projection grid defined …


Examination Of The Potential Of Terrestrial Laser Scanning And Structure-From-Motion Photogrammetry For Rapid Nondestructive Field Measurement Of Grass Biomass, Sam D. Cooper, David P. Roy, Crystal B. Schaaf, Ian Paynter May 2017

Examination Of The Potential Of Terrestrial Laser Scanning And Structure-From-Motion Photogrammetry For Rapid Nondestructive Field Measurement Of Grass Biomass, Sam D. Cooper, David P. Roy, Crystal B. Schaaf, Ian Paynter

GSCE Faculty Publications

Above ground biomass (AGB) is a parameter commonly used for assessment of grassland systems. Destructive AGB measurements, although accurate, are time consuming and are not easily undertaken on a repeat basis or over large areas. Structure-from-Motion (SfM) photogrammetry and Terrestrial Laser Scanning (TLS) are two technologies that have the potential to yield precise 3D structural measurements of vegetation quite rapidly. Recent advances have led to the successful application of TLS and SfM in woody biomass estimation, but application in natural grassland systems remains largely untested. The potential of these techniques for AGB estimation is examined considering 11 grass plots with …


Impacts Of Thermal Time On Land Surface Phenology In Urban Areas, Cole Krehbiel, Xiaoyang Zhang, Geoffrey Henebry May 2017

Impacts Of Thermal Time On Land Surface Phenology In Urban Areas, Cole Krehbiel, Xiaoyang Zhang, Geoffrey Henebry

GSCE Faculty Publications

Urban areas alter local atmospheric conditions by modifying surface albedo and consequently the surface radiation and energy balances, releasing waste heat from anthropogenic uses, and increasing atmospheric aerosols, all of which combine to increase temperatures in cities, especially overnight, compared with surrounding rural areas, resulting in a phenomenon called the “urban heat island" effect. Recent rapid urbanization of the planet has generated calls for remote sensing research related to the impacts of urban areas and urbanization on the natural environment. Spatially extensive, high spatial resolution data products are needed to capture phenological patterns in regions with heterogeneous land cover and …


Grand Challenges In Understanding The Interplay Of Climate And Land Changes, Shuguang Liu, Ben Bond-Lamberty, Lena R. Boysen, James D. Ford, Andrew Fox, Kevin Gallo, Jerry Hatfield, Geoffrey M. Henebry, Thomas G. Huntington, Zhihua Liu, Thomas R. Loveland, Richard J. Norby, Terry Sohl, Allison L. Steiner, Wenping Yuan, Zhao Zhang, Shuqing Zhao Apr 2017

Grand Challenges In Understanding The Interplay Of Climate And Land Changes, Shuguang Liu, Ben Bond-Lamberty, Lena R. Boysen, James D. Ford, Andrew Fox, Kevin Gallo, Jerry Hatfield, Geoffrey M. Henebry, Thomas G. Huntington, Zhihua Liu, Thomas R. Loveland, Richard J. Norby, Terry Sohl, Allison L. Steiner, Wenping Yuan, Zhao Zhang, Shuqing Zhao

GSCE Faculty Publications

Half of Earth’s land surface has been altered by human activities, creating various consequences on the climate and weather systems at local to global scales, which in turn affect a myriad of land surface processes and the adaptation behaviors. This study reviews the status and major knowledge gaps in the interactions of land and atmospheric changes and present 11 grand challenge areas for the scientific research and adaptation community in the coming decade. These land-cover and land-use change (LCLUC)-related areas include 1) impacts on weather and climate, 2) carbon and other biogeochemical cycles, 3) biospheric emissions, 4) the water cycle, …