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Full-Text Articles in Physical Sciences and Mathematics

Land-Use/Land-Cover Changes And Their Influence On The Ecosystem In Chengdu City, China During The Period Of 1992–2018, Xiaojuan Lin, Min Xu, Chunxiang Cao, Ramesh P. Singh, Wei Chen, Hongrun Ju Oct 2018

Land-Use/Land-Cover Changes And Their Influence On The Ecosystem In Chengdu City, China During The Period Of 1992–2018, Xiaojuan Lin, Min Xu, Chunxiang Cao, Ramesh P. Singh, Wei Chen, Hongrun Ju

Mathematics, Physics, and Computer Science Faculty Articles and Research

Due to urban expansion, economic development, and rapid population growth, land use/land cover (LULC) is changing in major cities around the globe. Quantitative analysis of LULC change is important for studying the corresponding impact on the ecosystem service value (ESV) that helps in decision-making and ecosystem conservation. Based on LULC data retrieved from remote-sensing interpretation, we computed the changes of ESV associated with the LULC dynamics using the benefits transfer method and geographic information system (GIS) technologies during the period of 1992–2018 following self-modified coefficients which were corrected by net primary productivity (NPP). This improved approach aimed to establish a …


Estimation Of The Relationship Between Satellite-Derived Vegetation Indices And Live Fuel Moisture Towards Wildfire Risk In Southern California, Kristen Whitney, Seung Hee Kim, Shenyue Jia, Menas Kafatos Aug 2018

Estimation Of The Relationship Between Satellite-Derived Vegetation Indices And Live Fuel Moisture Towards Wildfire Risk In Southern California, Kristen Whitney, Seung Hee Kim, Shenyue Jia, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Southern California possesses a Mediterranean climate having semi-arid to arid characteristics and contains shrubland areas at high risk to wildfire. To assess wildfire danger, fire agencies have been monitoring the moisture of vegetation, called live fuel moisture (LFM), using field-based sampling. Unfortunately, spatial and temporal resolution of live fuel moisture data are significantly limited because sampling is labor intensive. Remote sensing satellite data has been used to monitor vegetation moisture content and health of shrublands. Therefore, a potential approach to overcome the limitations of manual measurements of live fuel moisture is to use vegetation indices (VIs) derived from satellite data. …


Spectrally Based Bathymetric Mapping Of A Dynamic, Sandbedded Channel: Niobrara River, Nebraska, Usa, E. Dilbone, C.J. Legleiter, J.S. Alexander, B. Mcelroy Feb 2018

Spectrally Based Bathymetric Mapping Of A Dynamic, Sandbedded Channel: Niobrara River, Nebraska, Usa, E. Dilbone, C.J. Legleiter, J.S. Alexander, B. Mcelroy

United States Geological Survey: Staff Publications

Methods for spectrally based mapping of river bathymetry have been developed and tested in clear‐flowing, gravel‐bed channels, with limited application to turbid, sandbed rivers. This study used hyperspectral images and field surveys from the dynamic, sandy Niobrara River to evaluate three depth retrieval methods. The first regressionbased approach, optimal band ratio analysis (OBRA), paired in situ depth measurements with image pixel values to estimate depth. The second approach used ground‐based field spectra to calibrate an OBRA relationship. The third technique, image‐to‐depth quantile transformation (IDQT), estimated depth by linking the cumulative distribution function (CDF) of depth to the CDF of an …


The Spatial Sensitivity Of The Spectral Diversity–Biodiversity Relationship: An Experimental Test In A Prairie Grassland, Ran Wang, John A. Gamon, Jeannine Cavender-Bares, Philip A. Townsend, Arthur I. Zygielbaum Jan 2018

The Spatial Sensitivity Of The Spectral Diversity–Biodiversity Relationship: An Experimental Test In A Prairie Grassland, Ran Wang, John A. Gamon, Jeannine Cavender-Bares, Philip A. Townsend, Arthur I. Zygielbaum

School of Natural Resources: Faculty Publications

Remote sensing has been used to detect plant biodiversity in a range of ecosystems based on the varying spectral properties of different species or functional groups. However, the most appropriate spatial resolution necessary to detect diversity remains unclear. At coarse resolution, differences among spectral patterns may be too weak to detect. In contrast, at fine resolution, redundant information may be introduced. To explore the effect of spatial resolution, we studied the scale dependence of spectral diversity in a prairie ecosystem experiment at Cedar Creek Ecosystem Science Reserve, Minnesota, USA. Our study involved a scaling exercise comparing synthetic pixels resampled from …


The Spatial Sensitivity Of The Spectral Diversity–Biodiversity Relationship: An Experimental Test In A Prairie Grassland, Ran Wang, John A. Gamon, Jeannine Cavender-Bares, Philip A. Townsend, Arthur I. Zygielbaum Jan 2018

The Spatial Sensitivity Of The Spectral Diversity–Biodiversity Relationship: An Experimental Test In A Prairie Grassland, Ran Wang, John A. Gamon, Jeannine Cavender-Bares, Philip A. Townsend, Arthur I. Zygielbaum

School of Natural Resources: Faculty Publications

Remote sensing has been used to detect plant biodiversity in a range of ecosystems based on the varying spectral properties of different species or functional groups. However, the most appropriate spatial resolution necessary to detect diversity remains unclear. At coarse resolution, differences among spectral patterns may be too weak to detect. In contrast, at fine resolution, redundant information may be introduced. To explore the effect of spatial resolution, we studied the scale dependence of spectral diversity in a prairie ecosystem experiment at Cedar Creek Ecosystem Science Reserve, Minnesota, USA. Our study involved a scaling exercise comparing synthetic pixels resampled from …


Assessing Spatio-Temporal Patterns Of Forest Decline Across A Diverse Landscape In The Klamath Mountains Using A 28-Year Landsat Time-Series Analysis, Drew S. Bost Jan 2018

Assessing Spatio-Temporal Patterns Of Forest Decline Across A Diverse Landscape In The Klamath Mountains Using A 28-Year Landsat Time-Series Analysis, Drew S. Bost

Cal Poly Humboldt theses and projects

Rates of tree mortality in California and the Pacific Northwest have greatly increased in recent years, driven largely by pest and pathogen outbreaks as well as the effects of hotter, warmer droughts. While there have been a multitude of regional-scale assessments of mortality and forest decline, landscape-level studies are necessary to better identify forests that are most vulnerable to decline and to anticipate future changes. This need is particularly notable in the remote and little-studied mountains of northwest California, which are renowned for their diverse, heterogeneous vegetation types. A recent observation of elevated levels of Shasta red fir (Abies …