5 datasets found
  1. r

    Global analysis of slope of forest land

    • researchdata.se
    Updated Aug 7, 2023
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    Mikael Lundbäck (2023). Global analysis of slope of forest land [Dataset]. http://doi.org/10.5878/e7e8-rz29
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    (10850765), (1201408884)Available download formats
    Dataset updated
    Aug 7, 2023
    Dataset provided by
    Swedish University of Agricultural Sciences
    Authors
    Mikael Lundbäck
    License

    Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
    License information was derived automatically

    Time period covered
    2000 - 2013
    Area covered
    Asia, Australia, Oceania, North America, Europe, Africa, South America
    Description

    Forests of the world constitute one third of the total land area and are critical for e.g. carbon balance, biodiversity, water supply, and as source for bio-based products. Although the terrain within forest land has a great impact on accessibility, there is a lack of knowledge about the distribution of its variation in slope. The aim was to address that knowledge gap and create a globally consistent dataset of the distribution and area of forest land within different slope classes. A Geographic Information System (GIS) analysis was performed using the open source QGIS, GDAL, and R software. The core of the analysis was a digital elevation model and a forest cover mask, both with a final resolution of 90 metres. The total forest area according to the forest mask was 4.15 billion hectares whereof 82% was on slope less than 15°. The remaining 18% was distributed over the following slope classes, with 6% on a 15-20° slope, 8% on a 20-30° slope, and 4% on a slope >30°. Out of the major forestry countries, China had the largest proportion of forest steeper than 15° followed by Chile and India. A sensitivity analysis with 20 metres resolution resulted in increased steep areas by 1 percent point in flat Sweden and by 11 percent points in steep Austria. In addition to country-specific and aggregated results of slope distribution and forest area, a global raster dataset is also made freely available, to cover user-specific areas that are not necessarily demarcated by country borders. Apart from predicting the regional possibilities for different harvesting equipment, which was the original idea behind this study, the results can be used to relate geographical forest variables to slope. The results could also be used in strategic forest fire fighting and large scale planning of forest conservation and management.

    Raster dataset in GeoTIFF format. The data is unprojected (EPSG: 4326) and the resolution is 90 m at most, however the map-unit is degrees.

    Five files in total where the number in the filename indicates the proximity to the equator. File with number 1 covers the area from 0 to 49 degrees latitude, both north and south, number 2N covers latitude 50-59° north, number 2S covers latitude 50-59° south, number 3 covers latitude 60-69° north and number 4 covers latitude 70-79° north.

    The GeoTIFF files are in high resolution and are intended to be used with GIS software. We also provide PNG versions of the raster datasets, with XML geographic metadata, generated using GDAL in low resolution, to enable quick preview with a standard picture viewer.

  2. DInSAR_Carboni et al. 2021

    • figshare.com
    zip
    Updated Jun 2, 2023
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    Filippo Carboni; massimiliano porreca; Emanuela Valerio; manzo Mariarosaria; Claudio De Luca; salvatore azzaro; maurizio ercoli; massimiliano r. barchi (2023). DInSAR_Carboni et al. 2021 [Dataset]. http://doi.org/10.6084/m9.figshare.17128943.v2
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    zipAvailable download formats
    Dataset updated
    Jun 2, 2023
    Dataset provided by
    Figsharehttp://figshare.com/
    Authors
    Filippo Carboni; massimiliano porreca; Emanuela Valerio; manzo Mariarosaria; Claudio De Luca; salvatore azzaro; maurizio ercoli; massimiliano r. barchi
    License

    Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
    License information was derived automatically

    Description

    We here include the surface coseismic ruptures interpreted from the VDM in kmz, the DInSAR slope analysis performed in QGis as a GeoTiff (WGS84-UTM33N, EPSG:32633) and the ASCII file of the VDM 1 and HDM1.

  3. n

    Data for: Predicting habitat suitability for Townsend’s big-eared bats...

    • data.niaid.nih.gov
    • datadryad.org
    zip
    Updated Dec 12, 2022
    + more versions
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    Natalie Hamilton; Michael Morrison; Leila Harris; Joseph Szewczak; Scott Osborn (2022). Data for: Predicting habitat suitability for Townsend’s big-eared bats across California in relation to climate change [Dataset]. http://doi.org/10.5061/dryad.4j0zpc8f1
    Explore at:
    zipAvailable download formats
    Dataset updated
    Dec 12, 2022
    Dataset provided by
    University of California, Davis
    California Department of Fish and Wildlife
    California State Polytechnic University
    Texas A&M University
    Authors
    Natalie Hamilton; Michael Morrison; Leila Harris; Joseph Szewczak; Scott Osborn
    License

    https://spdx.org/licenses/CC0-1.0.htmlhttps://spdx.org/licenses/CC0-1.0.html

    Area covered
    California
    Description

    Aim: Effective management decisions depend on knowledge of species distribution and habitat use. Maps generated from species distribution models are important in predicting previously unknown occurrences of protected species. However, if populations are seasonally dynamic or locally adapted, failing to consider population level differences could lead to erroneous determinations of occurrence probability and ineffective management. The study goal was to model the distribution of a species of special concern, Townsend’s big-eared bats (Corynorhinus townsendii), in California. We incorporate seasonal and spatial differences to estimate the distribution under current and future climate conditions. Methods: We built species distribution models using all records from statewide roost surveys and by subsetting data to seasonal colonies, representing different phenological stages, and to Environmental Protection Agency Level III Ecoregions to understand how environmental needs vary based on these factors. We projected species’ distribution for 2061-2080 in response to low and high emissions scenarios and calculated the expected range shifts. Results: The estimated distribution differed between the combined (full dataset) and phenologically-explicit models, while ecoregion-specific models were largely congruent with the combined model. Across the majority of models, precipitation was the most important variable predicting the presence of C. townsendii roosts. Under future climate scnearios, distribution of C. townsendii is expected to contract throughout the state, however suitable areas will expand within some ecoregions. Main conclusion: Comparison of phenologically-explicit models with combined models indicate the combined models better predict the extent of the known range of C. townsendii in California. However, life history-explicit models aid in understanding of different environmental needs and distribution of their major phenological stages. Differences between ecoregion-specific and statewide predictions of habitat contractions highlight the need to consider regional variation when forecasting species’ responses to climate change. These models can aid in directing seasonally explicit surveys and predicting regions most vulnerable under future climate conditions. Methods Study area and survey data The study area covers the U.S. state of California, which has steep environmental gradients that support an array of species (Dobrowski et al. 2011). Because California is ecologically diverse, with regions ranging from forested mountain ranges to deserts, we examined local environmental needs by modeling at both the state-wide and ecoregion scale, using U.S. Environmental Protection Agency (EPA) Level III ecoregion designations and there are thirteen Level III ecoregions in California (Table S1.1) (Griffith et al. 2016). Species occurrence data used in this study were from a statewide survey of C. townsendii in California conducted by Harris et al. (2019). Briefly, methods included field surveys from 2014-2017 following a modified bat survey protocol to create a stratified random sampling scheme. Corynorhinus townsendii presence at roost sites was based on visual bat sightings. From these survey efforts, we have visual occurrence data for 65 maternity roosts, 82 hibernation roosts (hibernacula), and 91 active-season non-maternity roosts (transition roosts) for a total of 238 occurrence records (Figure 1, Table S1.1). Ecogeographical factors We downloaded climatic variables from WorldClim 2.0 bioclimatic variables (Fick & Hijmans, 2017) at a resolution of 5 arcmin for broad-scale analysis and 30 arcsec for our ecoregion-specific analyses. To calculate elevation and slope, we used a digital elevation model (USGS 2022) in ArcGIS 10.8.1 (ESRI, 2006). The chosen set of environmental variables reflects knowledge on climatic conditions and habitat relevant to bat physiology, phenology, and life history (Rebelo et al. 2010, Razgour et al. 2011, Loeb and Winters 2013, Razgour 2015, Ancillotto et al. 2016). To trim the global environmental variables to the same extent (the state of California), we used the R package “raster” (Hijmans et al. 2022). We performed a correlation analysis on the raster layers using the “layerStats” function and removed variables with a Pearson’s coefficient > 0.7 (see Table 1 for final model variables). For future climate conditions, we selected three general circulation models (GCMs) based on previous species distribution models of temperate bat species (Razgour et al. 2019) [Hadley Centre Global Environment Model version 2 Earth Systems model (HadGEM3-GC31_LL; Webb, 2019), Institut Pierre-Simon Laplace Coupled Model 6th Assessment Low Resolution (IPSL-CM6A-LR; Boucher et al., 2018), and Max Planck Institute for Meteorology Earth System Model Low Resolution (MPI-ESM1-2-LR; Brovkin et al., 2019)] and two contrasting greenhouse concentration trajectories (Shared Socio-economic Pathways (SSPs): a steady decline pathway with CO2 concentrations of 360 ppmv (SSP1-2.6) and an increasing pathway with CO2 reaching around 2,000 ppmv (SSP5-8.5) (IPCC6). We modeled distribution for present conditions future (2061-2080) time periods. Because one aim of our study was to determine the consequences of changing climate, we changed only the climatic data when projecting future distributions, while keeping the other variables constant over time (elevation, slope). Species distribution modeling We generated distribution maps for total occurrences (maternity + hibernacula + transition, hereafter defined as “combined models”), maternity colonies , hibernacula, and transition roosts. To estimate the present and future habitat suitability for C. townsendii in California, we used the maximum entropy (MaxEnt) algorithm in the “dismo” R package (Hijmans et al. 2021) through the advanced computing resources provided by Texas A&M High Performance Research Computing. We chose MaxEnt to aid in the comparisons of state-wide and ecoregion-specific models as MaxEnt outperforms other approaches when using small datasets (as is the case in our ecoregion-specific models). We created 1,000 background points from random points in the environmental layers and performed a 5-fold cross validation approach, which divided the occurrence records into training (80%) and testing (20%) datasets. We assessed the performance of our models by measuring the area under the receiver operating characteristic curve (AUC; Hanley & McNeil, 1982), where values >0.5 indicate that the model is performing better than random, values 0.5-0.7 indicating poor performance, 0.7-0.9 moderate performance and values of 0.9-1 excellent performance (BCCVL, Hallgren et al., 2016). We also measured the maximum true skill statistic (TSS; Allouche, Tsoar, & Kadmon, 2006) to assess model performance. The maxTSS ranges from -1 to +1:values <0.4 indicate a model that performs no better than random, 0.4-0.55 indicates poor performance, (0.55-0.7) moderate performance, (0.7-0.85) good performance, and values >0.80 indicate excellent performance (Samadi et al. 2022). Final distribution maps were generated using all occurrence records for each region (rather than the training/testing subset), and the models were projected onto present and future climate conditions. Additionally, because the climatic conditions of the different ecoregions of California vary widely, we generated separate models for each ecoregion in an attempt to capture potential local effects of climate change. A general rule in species distribution modeling is that the occurrence points should be 10 times the number of predictors included in the model, meaning that we would need 50 occurrences in each ecoregion. One common way to overcome this limitation is through the ensemble of small models (ESMs) (Breiner et al. 2015., 2018; Virtanen et al. 2018; Scherrer et al. 2019; Song et al. 2019) included in ecospat R package (references). For our ESMs we implemented MaxEnt modeling, and the final ensemble model was created by averaging individual bivariate models by weighted performance (AUC > 0.5). We also used null model significance testing with to evaluate the performance of our ESMs (Raes and Ter Steege 2007). To perform null model testing we compared AUC scores from 100 null models using randomly generated presence locations equal to the number used in the developed distribution model. All ecoregion models outperformed the null expectation (p<0.002). Estimating range shifts For each of the three GCMs and each RCP scenario, we converted the probability distribution map into a binary map (0=unsuitable, 1=suitable) using the threshold that maximizes sensitivity and specificity (Liu et al. 2016). To create the final maps for each SSP scenario, we summed the three binary GCM layers and took a consensus approach, meaning climatically suitable areas were pixels where at least two of the three models predicted species presence (Araújo and New 2007, Piccioli Cappelli et al. 2021). We combined the future binary maps (fmap) and the present binary maps (pmap) following the formula fmap x 2 + pmap (from Huang et al., 2017) to produce maps with values of 0 (areas not suitable), 1 (areas that are suitable in the present but not the future), 2 (areas that are not suitable in the present but suitable in the future), and 3 (areas currently suitable that will remain suitable) using the raster calculator function in QGIS. We then calculated the total area of suitability, area of maintenance, area of expansion, and area of contraction for each binary model using the “BIOMOD_RangeSize” function in R package “biomod2” (Thuiller et al. 2021).

  4. Z

    Warm Core Ring Trajectories in the Northwest Atlantic Slope Sea (2011-2020)

    • data.niaid.nih.gov
    • zenodo.org
    Updated Apr 11, 2022
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    Adrienne Silver (2022). Warm Core Ring Trajectories in the Northwest Atlantic Slope Sea (2011-2020) [Dataset]. https://data.niaid.nih.gov/resources?id=zenodo_6436379
    Explore at:
    Dataset updated
    Apr 11, 2022
    Dataset provided by
    Adrienne Silver
    Avijit Gangopadhyay
    Glen Gawarkiewicz
    License

    Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
    License information was derived automatically

    Description

    This dataset contains weekly trajectory information of Gulf Stream Warm Core Rings from 2011-2020. This dataset is comprised of individual files containing each ring’s weekly center location and its area for 282 WCRs present between January 1, 2011 and December 31, 2020. Each Warm Core Ring and is identified by a unique alphanumeric code 'WEyyyymmddA', where 'WE' represents a Warm Eddy (as identified in the analysis charts); 'yyyymmdd' is the year, month and day of formation; and the last character 'A' represents the sequential sighting of the eddies in a particular year. Continuity of a ring which passes from one year to the next is maintained by the same character in the first sighting. For example, the first ring in 2017 having a trailing alphabet of 'E' indicates that four rings were carried over from 2016 which were still observed on January 1, 2017. Each ring has its own netCDF (.nc) filename following its alphanumeric code. Each file contains 4 variables, “Lon”- the ring center’s weekly longitude, “Lat”- the ring center’s weekly latitude, “Area” - the rings weekly size in km2, and “Date” in days - representing the week since Jan 01, 0000.

    The process of creating the WCR tracking dataset follows the same methodology of the previously generated WCR census (Gangopadhyay et al., 2019, 2020). The Jenifer Clark’s Gulf Stream Charts used to create this dataset are 2-3 times a week from 2011-2020. Thus, we used approximately 1560 Charts for the 10 years of analysis. All of these charts were reanalyzed between 75° and 55°W using QGIS 2.18.16 (2016) and geo-referenced on a WGS84 coordinate system (Decker, 1986).

    Gangopadhyay, A., G. Gawarkiewicz, N. Etige, M. Monim and J. Clark, 2019. An Observed Regime Shift in the Formation of Warm Core Rings from the Gulf Stream, Nature - Scientific Reports, https://doi.org/10.1038/s41598-019-48661-9. www.nature.com/articles/s41598-019-48661-9.

    Gangopadhyay, A., N. Etige, G. Gawarkiewicz, A. M. Silver, M. Monim and J. Clark, 2020. A Census of the Warm Core Rings of the Gulf Stream (1980-2017). Journal of Geophysical Research, Oceans, 125, e2019JC016033. https://doi.org/10.1029/2019JC016033.

    QGIS Development Team. QGIS Geographic Information System (2016).

    Decker, B. L. World Geodetic System 1984. World geodetic system 1984 (1986).

  5. Warm Core Ring Trajectories in the Northwest Atlantic Slope Sea (2000-2010)

    • zenodo.org
    • data.niaid.nih.gov
    nc, zip
    Updated Dec 8, 2022
    + more versions
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    Nicholas Porter; Nicholas Porter; Adrienne Silver; Adrienne Silver; Avijit Gangopadhyay; Avijit Gangopadhyay (2022). Warm Core Ring Trajectories in the Northwest Atlantic Slope Sea (2000-2010) [Dataset]. http://doi.org/10.5281/zenodo.7406675
    Explore at:
    nc, zipAvailable download formats
    Dataset updated
    Dec 8, 2022
    Dataset provided by
    Zenodohttp://zenodo.org/
    Authors
    Nicholas Porter; Nicholas Porter; Adrienne Silver; Adrienne Silver; Avijit Gangopadhyay; Avijit Gangopadhyay
    License

    Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
    License information was derived automatically

    Description

    This dataset consists of weekly trajectory information of Gulf Stream Warm Core Rings from 2000-2010. This work builds upon Silver et al. (2022a) ( https://doi.org/10.5281/zenodo.6436380) which contained Warm Core Ring trajectory information from 2011 to 2020. Combining the two datasets a total of 21 years of weekly Warm Core Ring trajectories can be obtained. An example of how to use such a dataset can be found in Silver et al. (2022b).

    The format of the dataset is similar to that of Silver et al. (2022a), and the following description is adapted from their dataset. This dataset is comprised of individual files containing each ring’s weekly center location and its area for 374 WCRs present between January 1, 2000 and December 31, 2010. Each Warm Core Ring is identified by a unique alphanumeric code 'WEyyyymmddA', where 'WE' represents a Warm Eddy (as identified in the analysis charts); 'yyyymmdd' is the year, month and day of formation; and the last character 'A' represents the sequential sighting of the eddies in a particular year. Continuity of a ring which passes from one year to the next is maintained by the same character in the first sighting. For example, the first ring in 2002 having a trailing alphabet of 'F' indicates that five rings were carried over from 2001 which were still observed on January 1, 2002. Each ring has its own netCDF (.nc) filename following its alphanumeric code. Each file contains 4 variables, “Lon”- the ring center’s weekly longitude, “Lat”- the ring center’s weekly latitude, “Area” - the rings weekly size in km2, and “Date” in days - representing the days since Jan 01, 0000.

    The process of creating the WCR tracking dataset follows the same methodology of the previously generated WCR census (Gangopadhyay et al., 2019, 2020). The Jenifer Clark’s Gulf Stream Charts used to create this dataset are 2-3 times a week from 2000-2010. Thus, we used approximately 1560 Charts for the 10 years of analysis. All of these charts were reanalyzed between 75° and 55°W using QGIS 2.18.16 (2016) and geo-referenced on a WGS84 coordinate system (Decker, 1986).

    Silver, A., Gangopadhyay, A, & Gawarkiewicz, G. (2022a). Warm Core Ring Trajectories in the Northwest Atlantic Slope Sea (2011-2020) (1.0.0) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.6436380

    Silver, A., Gangopadhyay, A., Gawarkiewicz, G., Andres, M., Flierl, G., & Clark, J. (2022b). Spatial Variability of Movement, Structure, and Formation of Warm Core Rings in the Northwest Atlantic Slope Sea. Journal of Geophysical Research: Oceans, 127(8), e2022JC018737. https://doi.org/10.1029/2022JC018737

    Gangopadhyay, A., G. Gawarkiewicz, N. Etige, M. Monim and J. Clark, 2019. An Observed Regime Shift in the Formation of Warm Core Rings from the Gulf Stream, Nature - Scientific Reports, https://doi.org/10.1038/s41598-019-48661-9. www.nature.com/articles/s41598-019-48661-9.

    Gangopadhyay, A., N. Etige, G. Gawarkiewicz, A. M. Silver, M. Monim and J. Clark, 2020. A Census of the Warm Core Rings of the Gulf Stream (1980-2017). Journal of Geophysical Research, Oceans, 125, e2019JC016033. https://doi.org/10.1029/2019JC016033.

    QGIS Development Team. QGIS Geographic Information System (2016).

    Decker, B. L. World Geodetic System 1984. World geodetic system 1984 (1986).

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    Learn how you can add new datasets to our index.

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Mikael Lundbäck (2023). Global analysis of slope of forest land [Dataset]. http://doi.org/10.5878/e7e8-rz29

Global analysis of slope of forest land

Explore at:
3 scholarly articles cite this dataset (View in Google Scholar)
(10850765), (1201408884)Available download formats
Dataset updated
Aug 7, 2023
Dataset provided by
Swedish University of Agricultural Sciences
Authors
Mikael Lundbäck
License

Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
License information was derived automatically

Time period covered
2000 - 2013
Area covered
Asia, Australia, Oceania, North America, Europe, Africa, South America
Description

Forests of the world constitute one third of the total land area and are critical for e.g. carbon balance, biodiversity, water supply, and as source for bio-based products. Although the terrain within forest land has a great impact on accessibility, there is a lack of knowledge about the distribution of its variation in slope. The aim was to address that knowledge gap and create a globally consistent dataset of the distribution and area of forest land within different slope classes. A Geographic Information System (GIS) analysis was performed using the open source QGIS, GDAL, and R software. The core of the analysis was a digital elevation model and a forest cover mask, both with a final resolution of 90 metres. The total forest area according to the forest mask was 4.15 billion hectares whereof 82% was on slope less than 15°. The remaining 18% was distributed over the following slope classes, with 6% on a 15-20° slope, 8% on a 20-30° slope, and 4% on a slope >30°. Out of the major forestry countries, China had the largest proportion of forest steeper than 15° followed by Chile and India. A sensitivity analysis with 20 metres resolution resulted in increased steep areas by 1 percent point in flat Sweden and by 11 percent points in steep Austria. In addition to country-specific and aggregated results of slope distribution and forest area, a global raster dataset is also made freely available, to cover user-specific areas that are not necessarily demarcated by country borders. Apart from predicting the regional possibilities for different harvesting equipment, which was the original idea behind this study, the results can be used to relate geographical forest variables to slope. The results could also be used in strategic forest fire fighting and large scale planning of forest conservation and management.

Raster dataset in GeoTIFF format. The data is unprojected (EPSG: 4326) and the resolution is 90 m at most, however the map-unit is degrees.

Five files in total where the number in the filename indicates the proximity to the equator. File with number 1 covers the area from 0 to 49 degrees latitude, both north and south, number 2N covers latitude 50-59° north, number 2S covers latitude 50-59° south, number 3 covers latitude 60-69° north and number 4 covers latitude 70-79° north.

The GeoTIFF files are in high resolution and are intended to be used with GIS software. We also provide PNG versions of the raster datasets, with XML geographic metadata, generated using GDAL in low resolution, to enable quick preview with a standard picture viewer.

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