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Articles 61 - 89 of 89

Full-Text Articles in Spatial Science

A Comparison Of Tropical Rainforest Phenology Retrieved From Geostationary (Seviri) And Polar-Orbiting (Modis) Sensors Across The Congo Basin, Dong Yan, Xiaoyang Zhang, Yunyue Yu, Wei Guo Aug 2016

A Comparison Of Tropical Rainforest Phenology Retrieved From Geostationary (Seviri) And Polar-Orbiting (Modis) Sensors Across The Congo Basin, Dong Yan, Xiaoyang Zhang, Yunyue Yu, Wei Guo

GSCE Faculty Publications

The seasonal and interannual dynamics of tropical rainforests play a critical role in the global carbon cycle and climate change. This paper retrieved and compared land surface phenology from observations acquired by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard geostationary satellites and the Moderate Resolution Imaging Spectroradiometer (MODIS) on polar-orbiting satellites over the Congo Basin. To achieve this,we first retrieved canopy greenness cycles (CGCs) and their transition timing from two-band enhanced vegetation index (EVI2) derived from SEVIRI and MODIS data between 2006 and 2013.We then assessed the influences of SEVIRI and MODIS data quality on the reconstruction of …


Land Cover Data For The Mississippi-Alabama Barrier Islands, 2010-2011 Arcgis V10.3 Geodatabase, Gregory A. Carter, Carlton P. Anderson, Kelly L. Lucas, Nathan L. Hopper Jul 2016

Land Cover Data For The Mississippi-Alabama Barrier Islands, 2010-2011 Arcgis V10.3 Geodatabase, Gregory A. Carter, Carlton P. Anderson, Kelly L. Lucas, Nathan L. Hopper

Land Cover Data for the Mississippi-Alabama Barrier Islands, 2010-2011

Land cover on the Mississippi-Alabama barrier islands was surveyed in 2010-2011 as part of continuing research on island geomorphic and vegetation dynamics following the 2005 impact of Hurricane Katrina. Results of the survey include sub-meter GPS location, a listing of dominant vegetation species and field photographs recorded at 375 sampling locations distributed among Cat, West Ship, East Ship, Horn, Sand, Petit Bois and West Dauphin Islands. The survey was conducted in a period of intensive remote sensing data acquisition over the northern Gulf of Mexico by federal, state and commercial organizations in response to the 2010 Macondo Well (Deepwater Horizon) …


The Influences Of Drought And Land-Cover Conversion On Inter-Annual Variation Of Npp In The Three-North Shelterbelt Program Zone Of China Based On Modis Data, Dailiang Peng, Chaoyang Wu, Bing Zhang, Alfredo Huete, Xiaoyang Zhang, Rui Sun, Liping Lei, Wenjing Huang, Liangyun Liu, Xinjie Liu, Jun Li, Shezhou Luo, Bin Fang Jun 2016

The Influences Of Drought And Land-Cover Conversion On Inter-Annual Variation Of Npp In The Three-North Shelterbelt Program Zone Of China Based On Modis Data, Dailiang Peng, Chaoyang Wu, Bing Zhang, Alfredo Huete, Xiaoyang Zhang, Rui Sun, Liping Lei, Wenjing Huang, Liangyun Liu, Xinjie Liu, Jun Li, Shezhou Luo, Bin Fang

GSCE Faculty Publications

Terrestrial ecosystems greatly contribute to carbon (C) emission reduction targets through photosynthetic C uptake.Net primary production (NPP) represents the amount of atmospheric C fixed by plants and accumulated as biomass. The Three-North Shelterbelt Program (TNSP) zone accounts for more than 40% of China’s landmass. This zone has been the scene of several large-scale ecological restoration efforts since the late 1990s, and has witnessed significant changes in climate and human activities.Assessing the relative roles of different causal factors on NPP variability in TNSP zone is very important for establishing reasonable local policies to realize the emission reduction targets for central government. …


Identification Of Woodland Vernal Pools With Seasonal Change Palsar Data For Habitat Conservation, Laura Bourgeau-Chavez, Yu Man Lee, Michael Battaglia, Sarah L. Endres, Zachary Laubach, Kirk Scarbrough Jun 2016

Identification Of Woodland Vernal Pools With Seasonal Change Palsar Data For Habitat Conservation, Laura Bourgeau-Chavez, Yu Man Lee, Michael Battaglia, Sarah L. Endres, Zachary Laubach, Kirk Scarbrough

Michigan Tech Publications

Woodland vernal pools are important, small, cryptic, ephemeral wetland ecosystems that are vulnerable to a changing climate and anthropogenic influences. To conserve woodland vernal pools for the state of Michigan USA, vernal pool detection and mapping methods were sought that would be efficient, cost-effective, repeatable and accurate. Satellite-based L-band radar data from the high (10 m) resolution Japanese ALOS PALSAR sensor were evaluated for suitability in vernal pool detection beneath forest canopies. In a two phase study, potential vernal pool (PVP) detection was first assessed with unsupervised PALSAR (LHH) two season change detection (spring when flooded—summer when dry) and validated …


Using Residential Location To Assess The Environmental Value-Action Gap Of Students At James Madison University, Emma Rose Martin May 2016

Using Residential Location To Assess The Environmental Value-Action Gap Of Students At James Madison University, Emma Rose Martin

Senior Honors Projects, 2010-2019

This study focuses on the environmental Value-Action Gap of students at James Madison University (JMU) in Harrisonburg, Virginia. This gap occurs when a person has pro-environmental beliefs but does not have congruent actions. Often, there are other factors apart from a person’s values that influence his/her willingness to participate in eco-friendly behavior (Howell 2013). For this study, the factor of influence being addressed is location. When students live on-campus at JMU they are surrounded by ‘green’ initiatives. Understanding the diffusion of environmental behavior from on-campus living to off-campus living is important because the majority of a JMU student’s residency is …


Aquifer Vulnerability Modeling In New Jersey Through The Use Of Modified Drastic Methodology, Clement Uduk, Tanja Hopmans May 2016

Aquifer Vulnerability Modeling In New Jersey Through The Use Of Modified Drastic Methodology, Clement Uduk, Tanja Hopmans

Student Research Symposium

Due to the global average increase in temperature over the last 50 years, sea levels have been rising and making coastal aquifers more susceptible to saltwater intrusion. The average rate of sea level rise has increased from 2 mm/year to 3.5 mm/year during the twentieth century. The state of New Jersey is not only densely populated but the development along coastlines makes inundation a potential serious threat. New Jersey is diverse in aquifer types, in addition to the types of water bodies surrounding New Jersey, and makes for an interesting case study for groundwater vulnerability. The EPA has a universal …


Park Management Gis Intern In New York City Department Of Park & Recreation, Dongjun Zhou 3125032 Mar 2016

Park Management Gis Intern In New York City Department Of Park & Recreation, Dongjun Zhou 3125032

International Development, Community and Environment (IDCE)

My park management GIS internship with New York City Department of Parks & Recreation took place during June and August 2015, where I primarily worked under the guidance of Terese Flores, the park manager for the borough of Manhattan. My internship responsibility was assisting the Park Manager with park improvement project that primarily involved asset mapping for park properties, field data collecting and entry, budget devising as well as park staff coordinating. According to the requirement of GISDE program at Clark University, the content of this report mainly covers three aspects of this internship: the introduction for the mission and …


Cruising The Canal: A Methodological Approach To Assessing Trail Conditions Along The Hennepin Canal Parkway, Alyssa Clarida Feb 2016

Cruising The Canal: A Methodological Approach To Assessing Trail Conditions Along The Hennepin Canal Parkway, Alyssa Clarida

Geography: Student Scholarship & Creative Works

Trail conditions in the United States are degrading and trail systems do not receive enough funding to repair them in a timely manner. Park managers often conduct trail assessments to collect trail condition data. They use this data to make timely and judicious decisions regarding trail repairs. However, many trail assessments are time consuming, costly, and require high levels of expertise. This project creates a trail assessment methodology that can be applied to a trail with limited funds. The final methodology was efficient, succinct, accurate, and simple to conduct. It uses a problem based methodology where every instance of degradation …


Land Cover Land Use Change And Soil Organic Carbon Under Climate Variability In The Semi-Arid West African Sahel (1960-2050), Amadou M. Dieye Jan 2016

Land Cover Land Use Change And Soil Organic Carbon Under Climate Variability In The Semi-Arid West African Sahel (1960-2050), Amadou M. Dieye

Electronic Theses and Dissertations

Land Cover Land Use (LCLU) change affects land surface processes recognized to influence climate change at local, national and global levels. Soil organic carbon is a key component for the functioning of agro-ecosystems and has a direct effect on the physical, chemical and biological characteristics of the soil. The capacity to model and project LCLU change is of considerable interest for mitigation and adaptation measures in response to climate change. A combination of remote sensing analyses, qualitative social survey techniques, and biogeochemical modeling was used to study the relationships between climate change, LCLU change and soil organic carbon in the …


Simulating The Impacts Of Land-Use Land-Cover Changes On Cropland Carbon Fluxes In The Midwest Of The United States, Zhengpeng Li Jan 2016

Simulating The Impacts Of Land-Use Land-Cover Changes On Cropland Carbon Fluxes In The Midwest Of The United States, Zhengpeng Li

Electronic Theses and Dissertations

Understanding the major drivers of the cropland carbon fluxes is important for carbon management and greenhouse gas mitigation in agriculture. Past studies found that agricultural land-use and land-cover (LULC) changes, such as changes in cropland production technologies, tillage practices, and planted crop species, could have large impacts on carbon fluxes. However, the impacts remain highly uncertain at regional to global scales. Satellite remote sensing is commonly used to create products with geospatial information on LULC changes. This geospatial information can be integrated into biogeochemical models to simulate the spatial and temporal patterns of carbon fluxes. We used the General Ensemble …


Missing The Trees For The Forest: The Socioecological Significance Of Dispersed Farmland Trees In Northern Ethiopia, Jacob A. Wall Jan 2016

Missing The Trees For The Forest: The Socioecological Significance Of Dispersed Farmland Trees In Northern Ethiopia, Jacob A. Wall

Honors Theses

Scattered trees are prominent features in the agricultural landscape of the Ethiopian highlands. The dry Afromontane forests of the Amhara Region in northern Ethiopia have faced centuries of deforestation - the FAO estimates only 3% of the region is forested today. The remaining landscape has been largely converted into agricultural and grazing lands, with the exception of some limited government-protected lands, as well as thousands of small forest fragments left around Orthodox Churches (“church forests”). But while a growing body of scholarship has highlighted the ecological and cultural importance of church forests and other natural forest fragments, the roles of …


An Analysis Of Spatio-Temporal Landscape Patterns For Protected Areas In Northern New England: 1099-2010, Spencer Meyer, Mary-Kate Beard-Tisdale, Christopher S. Cronan, Robert Lilieholm Aug 2015

An Analysis Of Spatio-Temporal Landscape Patterns For Protected Areas In Northern New England: 1099-2010, Spencer Meyer, Mary-Kate Beard-Tisdale, Christopher S. Cronan, Robert Lilieholm

Publications

Context: Landscape ecology theory provides insight about how large assemblages of protected areas (PAs) should be configured to protect biodiversity. We adapted these theories to evaluate whether the emergence of decentralized land protection in a largely private landscape followed the principles of reserve design. Objectives: Our objectives were to determine: (1) Are there distinct clusters of PAs in time and space? (2) Are PAs becoming more spatially clustered through time? and (3) Does the resulting PA portfolio have traits characteristic of ideal reserve design? Methods: We developed an historical dataset of the PAs enacted since 1900 in the northern New …


Using Spatiotemporal Methods To Fill Gaps In Energy Usage Interval Data, Kristin K. Graves May 2015

Using Spatiotemporal Methods To Fill Gaps In Energy Usage Interval Data, Kristin K. Graves

Theses and Dissertations

Researchers analyzing spatiotemporal or panel data, which varies both in location and over time, often find that their data has holes or gaps. This thesis explores alternative methods for filling those gaps and also suggests a set of techniques for evaluating those gap-filling methods to determine which works best.


Monitoring Invasive Plant Species: Summer Internship At Habitat Wildlife Sanctuary, Belmont, Massachusetts, Holly M. Zanoni May 2015

Monitoring Invasive Plant Species: Summer Internship At Habitat Wildlife Sanctuary, Belmont, Massachusetts, Holly M. Zanoni

International Development, Community and Environment (IDCE)

Habitat Wildlife Sanctuary, located in Belmont, Massachusetts is a dynamic suburban sanctuary that effectively upholds Mass Audubon’s three-part mission of advocacy, conservation, and education. Invasive plants threaten ecological integrity; however, proactive measures are taken to mitigate further encroachment. This is accomplished by surveying and taking inventory for presence of invasive species, then prioritizing them, and finally by incorporating high priority species into the immediate management strategy. Four invasive plants were formally analyzed using geographic information science during the 2014 growing season: Garlic mustard, Black swallowwort, Japanese knotweed, and Dame’s Rocket. The resulting density maps detected pattern changes from 2011, 2012, …


Integrating Hands-On Undergraduate Research In An Applied Spatial Science Senior Level Capstone Course, David Kulhavy, Daniel R. Unger, I-Kuai Hung, David Douglass Jan 2015

Integrating Hands-On Undergraduate Research In An Applied Spatial Science Senior Level Capstone Course, David Kulhavy, Daniel R. Unger, I-Kuai Hung, David Douglass

Faculty Publications

A senior within a spatial science Ecological Planning capstone course designed an undergraduate research project to increase his spatial science expertise and to assess the hands-on instruction methodology employed within the Bachelor of Science in Spatial Science program at Stephen F Austin State University. The height of 30 building features estimated remotely with LiDAR data, within the Pictometry remotely sensed web-based interface, and in situ with a laser rangefinder were compared to actual building feature height measurements. A comparison of estimated height with actual height indicated that all three estimation techniques tested were unbiased estimators of height. An ANOVA, conducted …


Mitigation And Beautification: Placing Rain Gardens In The Keystone Neighborhood Of Rock Island, Illinois, Rosalie K. Starenko Jan 2015

Mitigation And Beautification: Placing Rain Gardens In The Keystone Neighborhood Of Rock Island, Illinois, Rosalie K. Starenko

Independent Research Projects

With new stormwater management regulations, cities are looking for strategies to reduce urban runoff, and rain gardens are one of several strategies that capture runoff and encourage infiltration and evaporation. In doing so, pollution from runoff is mitigated and combined sewer systems experience fewer overflow events. I argue as well that the implementation of rain gardens would act as a movement for neighborhood beautification. This research develops a new methodology for placing rain gardens that: 1) maximizes the aesthetic value of the gardens by favoring high-visibility locations and 2) targets locations that would best benefit from reduced stormwater runoff. The …


St. Norbert College As Arboretum: Mapping The Trees On Campus, Jordan A. Mayer, Jason Mills, David Hunnicut Jan 2015

St. Norbert College As Arboretum: Mapping The Trees On Campus, Jordan A. Mayer, Jason Mills, David Hunnicut

GIS Library

St. Norbert College as Arboretum: Mapping the Trees on Campus - Take a virtual tour of the trees on campus.

The tour is a multimedia ArcGIS Online story map and is available here.

Many of the trees on the St. Norbert Campus were planted by Fr. Anselm Keefe (1895- 1974) in the mid 20th century. It was Fr. Keefe’s vision to beautify the campus by creating gardens that were accessible to the public. This included planting a diverse variety of trees, including one of every tree species native to Wisconsin. It was Keefe’s mission to make St. Norbert College …


A Cross Comparison Of Spatiotemporally Enhanced Springtime Phenological Measurements From Satellites And Ground In A Northern U.S. Mixed Forest, Liang Liang, Mark D. Schwartz, Zhuosen Wang, Feng Gao, Crystal B. Schaaf, Bin Tan, Jeffrey T. Morisette, Xiaoyang Zhang Dec 2014

A Cross Comparison Of Spatiotemporally Enhanced Springtime Phenological Measurements From Satellites And Ground In A Northern U.S. Mixed Forest, Liang Liang, Mark D. Schwartz, Zhuosen Wang, Feng Gao, Crystal B. Schaaf, Bin Tan, Jeffrey T. Morisette, Xiaoyang Zhang

GSCE Faculty Publications

Cross comparison of satellite-derived land surface phenology (LSP) and ground measurements is useful to ensure the relevance of detected seasonal vegetation change to the underlying biophysical processes. While standard 16-day and 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation index (VI)-based springtime LSP has been evaluated in previous studies, it remains unclear whether LSP with enhanced temporal and spatial resolutions can capture additional details of ground phenology. In this paper, we compared LSP derived from 500-m daily MODIS and 30-m MODIS-Landsat fused VI data with landscape phenology (LP) in a northern U.S. mixed forest. LP was previously developed from intensively observed …


Overcoming Roadblocks In Introducing Virtual World Technology To High Schools, Casey Dylan Bailey Aug 2014

Overcoming Roadblocks In Introducing Virtual World Technology To High Schools, Casey Dylan Bailey

Graduate Theses and Dissertations

The EAST (Environmental And Spatial Technology) Initiative is a non-profit educational organization that provides students in over two hundred schools in eight states with access to advanced computing technologies for the purpose of enabling students to develop technical skills early and to produce solutions to local community problems. Although many high-end technologies are available through EAST, they are desktop solutions that individual students use and there are none that enable students within a school or between schools to collaborate.

This thesis is a saga that documents the identification and removal of many roadblocks to introducing a 3D multi-user virtual simulation …


Sensitivity Of Mesoscale Modeling Of Smoke Direct Radiative Effect To The Emission Inventory: A Case Study In Northern Sub-Saharan African Region, Feng Zhang, Jun Wang, Charles Ichoku, Edward J. Hyer, Zhifeng Yang, Cui Ge, Shenjian Su, Xiaoyang Zhang, Shobha Kondragunta, Christine Wiedinmyer, Johannes W. Kaiser, Arlindo Da Silva Jul 2014

Sensitivity Of Mesoscale Modeling Of Smoke Direct Radiative Effect To The Emission Inventory: A Case Study In Northern Sub-Saharan African Region, Feng Zhang, Jun Wang, Charles Ichoku, Edward J. Hyer, Zhifeng Yang, Cui Ge, Shenjian Su, Xiaoyang Zhang, Shobha Kondragunta, Christine Wiedinmyer, Johannes W. Kaiser, Arlindo Da Silva

GSCE Faculty Publications

An ensemble approach is used to examine the sensitivity of smoke loading and smoke direct radiative effect in the atmosphere to uncertainties in smoke emission estimates. Seven different fire emission inventories are applied independently to WRF-Chem model (v3.5) with the same model configuration (excluding dust and other emission sources) over the northern sub-Saharan African (NSSA) biomass-burning region. Results for November and February 2010 are analyzed, respectively representing the start and end of the biomass burning season in the study region. For February 2010, estimates of total smoke emission vary by a factor of 12, but only differences by factors of …


Interannual Variation In Biomass Burning And Fire Seasonality Derived From Geostationary Satellite Data Across The Contiguous United States From 1995 To 2011, Xiaoyang Zhang, Shobha Kondragunta, David Roy Jun 2014

Interannual Variation In Biomass Burning And Fire Seasonality Derived From Geostationary Satellite Data Across The Contiguous United States From 1995 To 2011, Xiaoyang Zhang, Shobha Kondragunta, David Roy

GSCE Faculty Publications

Wildfires exhibit a strong seasonality that is driven by climatic factors and human activities. Although the fire seasonality is commonly determined using burned area and fire frequency, it could also be quantified using biomass consumption estimates that directly represent biomass loss (a combination of the area burned and the fuel loading). Therefore, in this study a data set of long-term biomass consumed was derived from geostationary satellite data to explore the interannual variation in the fire seasonality and the possible impacts of climate change and land management practices across the Contiguous United States (CONUS). Specifically, daily biomass consumed data were …


Near-Real-Time Global Biomass Burning Emissions Product From Geostationary Satellite Constellation, Xiaoyang Zhang, Shobha Kondragunta, Jessica Ram, Christopher Schmidt, Ho-Chung Huang Jul 2012

Near-Real-Time Global Biomass Burning Emissions Product From Geostationary Satellite Constellation, Xiaoyang Zhang, Shobha Kondragunta, Jessica Ram, Christopher Schmidt, Ho-Chung Huang

GSCE Faculty Publications

Near-real-time estimates of biomass burning emissions are crucial for air quality monitoring and forecasting. We present here the first near-real-time global biomass burning emission product from geostationary satellites (GBBEP-Geo) produced from satellite-derived fire radiative power (FRP) for individual fire pixels. Specifically, the FRP is retrieved using WF_ABBA V65 (wildfire automated biomass burning algorithm) from a network of multiple geostationary satellites. The network consists of two Geostationary Operational Environmental Satellites (GOES) which are operated by the National Oceanic and Atmospheric Administration, the Meteosat second-generation satellites (Meteosat-09) operated by the European Organisation for the Exploitation of Meteorological Satellites, and the Multifunctional Transport …


Geospatial Tools And Techniques For Watershed Management Using Swat 2009, Naresh Pai Dec 2011

Geospatial Tools And Techniques For Watershed Management Using Swat 2009, Naresh Pai

Graduate Theses and Dissertations

In this study, geospatial tools and techniques were developed to support specific aspects of watershed pollution management, such as quantifying land-use change (LUC) impacts, prioritizing subwatersheds, and communicating field-scale impacts, using the soil and water assessment tool 2009 (SWAT 2009) model.

For the land-use change objective, a geospatial tool titled SWAT2009_LUC was developed that enables SWAT modelers to prepare specific input files for simulating concurrent land-use changes during the SWAT 2009 model simulations. Testing of the tool for the Illinois River Drainage Area in Arkansas (IRDAA) watershed showed that the tool accurately represented temporal land-uses within the model. Model simulations …


Strategies For The Fusion Of Satellite Fire Radiative Power With Burned Area Data For Fire Radiative Energy Derivation, Luigi Boschetti, David P. Roy Oct 2009

Strategies For The Fusion Of Satellite Fire Radiative Power With Burned Area Data For Fire Radiative Energy Derivation, Luigi Boschetti, David P. Roy

GSCE Faculty Publications

Instantaneous estimates of the power released by a fire (Fire Radiative Power, FRP) are available with satellite active fire detection products. Integrating FRP in time provides an estimate of the total energy released (Fire Radiative Energy, FRE), which can be converted into burned biomass estimates needed by the atmospheric emissions modeling community. While straightforward in theory, the integration of FRP in time and space is affected by temporal and spatial undersampling imposed by the satellite sensing and orbit geometry, clouds, and active fire product omission errors. Combination of active fire FRP estimates with independently derived burned area maps provides the …


Spatial Analyses And Repletion Of Gargathy Coastal Lagoon, Loreto Herraiz Gomez Oct 2008

Spatial Analyses And Repletion Of Gargathy Coastal Lagoon, Loreto Herraiz Gomez

OES Theses and Dissertations

Coastal lagoons and bays vary in shape and size in response to antecedent topography, geologic processes and sea level rise. Variations in shape and environmental conditions of coastal basins are believed to influence the distribution of benthic sub-environments and the exchange of water with the ocean and other adjacent coastal systems. Gargathy Inlet and its coastal lagoon vary spatially from the inlet, where the greatest depths are observed, to the mainland, dominated by shallow intertidal areas, colonized by marsh. Hypsographic and hydro-hypsographic analyses of Gargathy's coastal lagoon were the primary techniques applied to understand the relative distribution of the benthic …


Defining A Fire Year For Reporting And Analysis Of Global Interannual Fire Variablility, Luigi Boschetti, David P. Roy Aug 2008

Defining A Fire Year For Reporting And Analysis Of Global Interannual Fire Variablility, Luigi Boschetti, David P. Roy

GSCE Faculty Publications

The interannual variability of fire activity has been studied without an explicit investigation of a suitable starting month for yearly calculations. Sensitivity analysis of 37 months of global MODIS active fire detections indicates that a 1-month change in the start of the fire year definition can lead, in the worst case, to a difference of over 6% and over 45% in global and subcontinental scale annual fire totals, respectively. Optimal starting months for analyses of global and subcontinental fire interannual variability are described. The research indicates that a fire year starting in March provides an optimal definition for annual global …


Large Seasonal Swings In Leaf Area Of Amazon Rainforests, Ranga B. Myneni, Wenze Yang, Ramakrishna R. Nemani, Alfredo R. Huete, Robert E. Dickinson, Yuri Knyazikhin, Kamel Didan, Rong Fu, Robinson I. Negron Juarez, Sasan S. Saatchi, Hirofumi Hashimoto, Kazuhito Ichii, Nikolay V. Shabanov, Bin Tan, Piyachat Ratana, Jeffrey L. Privette, Jeffrey T. Morisette, Eric F. Vermote, David P. Roy, Robert E. Wolfe, Mark A. Friedl, Steven W. Running, Petr Votava, Nazmi El-Saleous, Sadashiva Devadiga, Yin Su, Vincent V. Salomonson Mar 2007

Large Seasonal Swings In Leaf Area Of Amazon Rainforests, Ranga B. Myneni, Wenze Yang, Ramakrishna R. Nemani, Alfredo R. Huete, Robert E. Dickinson, Yuri Knyazikhin, Kamel Didan, Rong Fu, Robinson I. Negron Juarez, Sasan S. Saatchi, Hirofumi Hashimoto, Kazuhito Ichii, Nikolay V. Shabanov, Bin Tan, Piyachat Ratana, Jeffrey L. Privette, Jeffrey T. Morisette, Eric F. Vermote, David P. Roy, Robert E. Wolfe, Mark A. Friedl, Steven W. Running, Petr Votava, Nazmi El-Saleous, Sadashiva Devadiga, Yin Su, Vincent V. Salomonson

GSCE Faculty Publications

Despite early speculation to the contrary, all tropical forests studied to date display seasonal variations in the presence of new leaves, flowers, and fruits. Past studies were focused on the timing of phenological events and their cues but not on the accompanying changes in leaf area that regulate vegetation–atmosphere exchanges of energy, momentum, and mass. Here we report, from analysis of 5 years of recent satellite data, seasonal swings in green leaf area of ~25% in a majority of the Amazon rainforests. This seasonal cycle is timed to the seasonality of solar radiation in a manner that is suggestive of …


Fire-Induced Albedo Change And Its Radative Forcing At The Surface In Northern Austrailia, Y. Jin, David P. Roy Jul 2005

Fire-Induced Albedo Change And Its Radative Forcing At The Surface In Northern Austrailia, Y. Jin, David P. Roy

GSCE Faculty Publications

This paper investigates the impact of fire on surface albedo and the associated radiative forcing over 56% of continental Australia encompassing the fire-prone northern tropical savanna. Fire-affected areas and albedos are derived for the 2003 fire season using daily Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance data. Near-infrared and total shortwave albedos are observed to generally decrease after fire occurrence. Regionally, the total shortwave albedo drops by an average of 0.024, with increasing reductions as the dry season progresses and larger reductions in grasslands than woody savannas. These fire-induced albedo changes exert a positive forcing at the surface that increases …


Gis Characterization Of Beaver Watershed, H. D. Scott, J. M. Mckimmey Jun 1992

Gis Characterization Of Beaver Watershed, H. D. Scott, J. M. Mckimmey

Technical Reports

Beaver Reservoir watershed is located in Northwest Arkansas including portions of Madison, Washington, Benton, Carroll, Franklin and Crawford counties. This watershed is important to the Northwest Arkansas region because it supplies most of the drinking water for the major towns and cities, and several rural water systems. The watershed consists of 308,971 ha with elevations ranging from approximately 341 m to 731 m above mean sea level. It includes the Springfield Plateau and the Boston Mountains provinces within the Ozark Plateau physiographic region. There are approximately 581 km of streams, 532 km of shore line, and 3712 km of roads …