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Abstract: Background: Urbanization is an important indicator of economic growth and social change but is associated with environmental degradation, which threatens sustainable growth of African cities. One of the most vulnerable ecosystems in urban areas are wetlands. In Uganda, wetlands cover an area of 11% of the country's land area. Half of the wetland areas in Ugandan cities have been converted to industry and residential areas, and urban agriculture. There is limited information on the extent of wetland conversion or utilization for urban agriculture. The objective of this study was to investigate the extent of wetlands lost in two Ugandan cities, Wakiso and Kampala, in the last 30 years. Secondly, we demonstrate a simple methodology to monitor agriculture on encroached wetlands. Methods: Using a field survey and free remote sensing data from Landsat TM 1986 and Landsat ETM 2016 we classified the rate of wetland loss and encroachment in the last 30 years. Using MODIS NDVI 16-day composites at 500-meter spatial resolution, we generated distinctive crops and crop mixtures in the encroached wetlands for urban agriculture using the ISODATA clustering algorithm. Results: Over a 30-year period, 72,828 ha (73%) of the Wakiso-Kampala wetlands have been lost. Agriculture area on the other hand doubled. Of the new cultivation area, 16,488 ha (23%) were reclaimed from wetlands. All cultivated agriculture in Kampala was in the wetlands while in Wakiso, 73% of crop agriculture was in the wetlands. The major crops grown in these urban wetlands were banana (20%), sugarcane (22%), maize (17%), Eucalyptus trees (12%), sweet potatoes (10%), while ornamental nurseries, pine trees, vegetables and passion fruits were each at 5%. Conclusions: Current wetland exploitation for food security for urban dwellers may be a trade-off between the provision of food in the short-term and the loss of important ecosystems services in the long-term. Category: geoscientificInformation Source: Not Available Supplemental Information: Not Availble Coverage: EVENT LABEL: * LATITUDE: 1.067000 * LONGITUDE: 31.883000 * LOCATION: Africa, Uganda * METHOD/DEVICE: Multiple investigations
Data Types:
  • File Set
Abstract: Background: Urbanization is an important indicator of economic growth and social change but is associated with environmental degradation, which threatens sustainable growth of African cities. One of the most vulnerable ecosystems in urban areas are wetlands. In Uganda, wetlands cover an area of 11% of the country's land area. Half of the wetland areas in Ugandan cities have been converted to industry and residential areas, and urban agriculture. There is limited information on the extent of wetland conversion or utilization for urban agriculture. The objective of this study was to investigate the extent of wetlands lost in two Ugandan cities, Wakiso and Kampala, in the last 30 years. Secondly, we demonstrate a simple methodology to monitor agriculture on encroached wetlands. Methods: Using a field survey and free remote sensing data from Landsat TM 1986 and Landsat ETM 2016 we classified the rate of wetland loss and encroachment in the last 30 years. Using MODIS NDVI 16-day composites at 500-meter spatial resolution, we generated distinctive crops and crop mixtures in the encroached wetlands for urban agriculture using the ISODATA clustering algorithm. Results: Over a 30-year period, 72,828 ha (73%) of the Wakiso-Kampala wetlands have been lost. Agriculture area on the other hand doubled. Of the new cultivation area, 16,488 ha (23%) were reclaimed from wetlands. All cultivated agriculture in Kampala was in the wetlands while in Wakiso, 73% of crop agriculture was in the wetlands. The major crops grown in these urban wetlands were banana (20%), sugarcane (22%), maize (17%), Eucalyptus trees (12%), sweet potatoes (10%), while ornamental nurseries, pine trees, vegetables and passion fruits were each at 5%. Conclusions: Current wetland exploitation for food security for urban dwellers may be a trade-off between the provision of food in the short-term and the loss of important ecosystems services in the long-term. Category: geoscientificInformation Source: Not Available Supplemental Information: Not Availble Coverage: EVENT LABEL: * LATITUDE: 1.067000 * LONGITUDE: 31.883000 * LOCATION: Africa, Uganda * METHOD/DEVICE: Multiple investigations
Data Types:
  • File Set
Abstract: Background: Urbanization is an important indicator of economic growth and social change but is associated with environmental degradation, which threatens sustainable growth of African cities. One of the most vulnerable ecosystems in urban areas are wetlands. In Uganda, wetlands cover an area of 11% of the country's land area. Half of the wetland areas in Ugandan cities have been converted to industry and residential areas, and urban agriculture. There is limited information on the extent of wetland conversion or utilization for urban agriculture. The objective of this study was to investigate the extent of wetlands lost in two Ugandan cities, Wakiso and Kampala, in the last 30 years. Secondly, we demonstrate a simple methodology to monitor agriculture on encroached wetlands. Methods: Using a field survey and free remote sensing data from Landsat TM 1986 and Landsat ETM 2016 we classified the rate of wetland loss and encroachment in the last 30 years. Using MODIS NDVI 16-day composites at 500-meter spatial resolution, we generated distinctive crops and crop mixtures in the encroached wetlands for urban agriculture using the ISODATA clustering algorithm. Results: Over a 30-year period, 72,828 ha (73%) of the Wakiso-Kampala wetlands have been lost. Agriculture area on the other hand doubled. Of the new cultivation area, 16,488 ha (23%) were reclaimed from wetlands. All cultivated agriculture in Kampala was in the wetlands while in Wakiso, 73% of crop agriculture was in the wetlands. The major crops grown in these urban wetlands were banana (20%), sugarcane (22%), maize (17%), Eucalyptus trees (12%), sweet potatoes (10%), while ornamental nurseries, pine trees, vegetables and passion fruits were each at 5%. Conclusions: Current wetland exploitation for food security for urban dwellers may be a trade-off between the provision of food in the short-term and the loss of important ecosystems services in the long-term. Category: geoscientificInformation Source: Not Available Supplemental Information: Not Availble Coverage: EVENT LABEL: * LATITUDE: 1.067000 * LONGITUDE: 31.883000 * LOCATION: Africa, Uganda * METHOD/DEVICE: Multiple investigations
Data Types:
  • File Set
Abstract: Background: Urbanization is an important indicator of economic growth and social change but is associated with environmental degradation, which threatens sustainable growth of African cities. One of the most vulnerable ecosystems in urban areas are wetlands. In Uganda, wetlands cover an area of 11% of the country's land area. Half of the wetland areas in Ugandan cities have been converted to industry and residential areas, and urban agriculture. There is limited information on the extent of wetland conversion or utilization for urban agriculture. The objective of this study was to investigate the extent of wetlands lost in two Ugandan cities, Wakiso and Kampala, in the last 30 years. Secondly, we demonstrate a simple methodology to monitor agriculture on encroached wetlands. Methods: Using a field survey and free remote sensing data from Landsat TM 1986 and Landsat ETM 2016 we classified the rate of wetland loss and encroachment in the last 30 years. Using MODIS NDVI 16-day composites at 500-meter spatial resolution, we generated distinctive crops and crop mixtures in the encroached wetlands for urban agriculture using the ISODATA clustering algorithm. Results: Over a 30-year period, 72,828 ha (73%) of the Wakiso-Kampala wetlands have been lost. Agriculture area on the other hand doubled. Of the new cultivation area, 16,488 ha (23%) were reclaimed from wetlands. All cultivated agriculture in Kampala was in the wetlands while in Wakiso, 73% of crop agriculture was in the wetlands. The major crops grown in these urban wetlands were banana (20%), sugarcane (22%), maize (17%), Eucalyptus trees (12%), sweet potatoes (10%), while ornamental nurseries, pine trees, vegetables and passion fruits were each at 5%. Conclusions: Current wetland exploitation for food security for urban dwellers may be a trade-off between the provision of food in the short-term and the loss of important ecosystems services in the long-term. Category: geoscientificInformation Source: Not Available Supplemental Information: Not Availble Coverage: EVENT LABEL: * LATITUDE: 1.067000 * LONGITUDE: 31.883000 * LOCATION: Africa, Uganda * METHOD/DEVICE: Multiple investigations
Data Types:
  • File Set
Abstract: Land cover is the physical evidence on the surface of the Earth. As the cause and result of global environmental change, land cover change (LCC) influences the global energy balance and biogeochemical cycles. Continuous and dynamic monitoring of global LC is urgently needed. Effective monitoring and comprehensive analysis of LCC at the global scale are rare. With the latest version of GLASS (The Global Land Surface Satellite) CDRs (Climate Data Records) from 1982 to 2015, we built the first record of 34-year long annual dynamics of global land cover (GLASS-GLC) at 5 km resolution using the Google Earth Engine (GEE) platform. Compared to earlier global LC products, GLASS-GLC is characterized by high consistency, more detailed, and longer temporal coverage. The average overall accuracy for the 34 years each with 7 classes, including cropland, forest, grassland, shrubland, tundra, barren land, and snow/ice, is 82.81 % based on 2431 test sample units. We implemented a systematic uncertainty analysis and carried out a comprehensive spatiotemporal pattern analysis. Significant changes at various scales were found, including barren land loss and cropland gain in the tropics, forest gain in northern hemisphere and grassland loss in Asia, etc. A global quantitative analysis of human factors showed that the average human impact level in areas with significant LCC was about 25.49 %. The anthropogenic influence has a strong correlation with the noticeable vegetation gain, especially for forest. Based on GLASS-GLC, we can conduct long-term LCC analysis, improve our understanding of global environmental change, and mitigate its negative impact. GLASS-GLC will be further applied in Earth system modeling to facilitate research on global carbon and water cycling, vegetation dynamics, and climate change. This GLASS-GLC data set is related to the paper at doi:10.5194/essd-2019-23. It consists of one readme file and 34 GeoTIFF files of annual 5 km global maps from 1982 to 2015 in a WGS 84 projection. Category: geoscientificInformation Source: Not Available Supplemental Information: Not Availble Coverage: Not Available
Data Types:
  • File Set
Abstract: The materials in this archive are organized as follows: 1) "katla" directory contains: - the processed seismograms (local earthquakes removed, decimated to a sampling rate of 10 Hz) in the "seismograms" directory - the correlation envelopes used in the real-data example (tremor at Katla volcano) in the "covariograms" directory - the MATLAB scripts to generate the correlation envelopes from the processed seismograms 2) "synthetic" directory contains: - the MATLAB scripts to generate synthetic data used in the synthetic tests Category: geoscientificInformation Source: Not Available Supplemental Information: Not Availble Coverage: EVENT LABEL: * LATITUDE: 63.633000 * LONGITUDE: -19.050000 * LOCATION: Iceland * METHOD/DEVICE: Multiple investigations
Data Types:
  • File Set
Abstract: ASCII files reporting the position time-series, in the Adria-fixed reference frame, of GNSS in the Eastern-Southern Alps The columns are: Time, E, N, Se, Sn, Ren, U, Su, Reu, Rnu, site, long, lati, representing, respectively, epoch (in decimal years), displacement in the East component (in mm), displacement in the North component (in mm), uncertainty (one standard deviation) of the East component (in mm), uncertainty (one standard deviation) of the North component (in mm), correlation between the East and North components, displacement in the Up component (in mm), uncertainty (one standard deviation) of the Up component (in mm), correlation between the East and Up components, correlation between the North and Up components, Station ID (four letters), Longitude of the station (°), Latitude of the station (°). Category: geoscientificInformation Source: Not Available Supplemental Information: Not Availble Coverage: Not Available
Data Types:
  • File Set
Abstract: Multicellularity is a key evolutionary innovation, leading to coordinated activity and resource sharing among cells, which generally occurs via the physical exchange of chemical compound. However, filamentous cable bacteria display a unique metabolism in which redox transformations in distant cells are coupled via long-distance electron transport rather than an exchange of chemicals. This challenges our understanding of organismal functioning, as the link between electron transfer, metabolism, energy conservation and filament growth in cable bacteria remains enigmatic. Here, we show that cells within individual filaments of cable bacteria display a remarkable dichotomy in biosynthesis that coincides with redox zonation. Nanoscale secondary ion mass spectrometry combined with 13C (bicarbonate and propionate) and 15N-ammonia isotope labelling reveals that cells performing sulphide oxidation in deeper anoxic horizons have a high assimilation rate, whereas cells performing oxygen reduction in the oxic zone show very little or no label uptake. Accordingly, oxygen reduction appears to merely function as a mechanism to quickly dispense of electrons with little to no energy conservation, while biosynthesis and growth are restricted to sulphide-respiring cells. Still, cells can immediately switch roles when redox conditions change, and show no differentiation, which suggests that the "community service" performed by the cells in the oxic zone is only temporary. Overall, our data reveal a division of labour and electrical cooperation among cells that has not been seen previously in multicellular organisms. Category: geoscientificInformation Source: Not Available Supplemental Information: Not Availble Coverage: Not Available
Data Types:
  • File Set
Abstract: We provide a present-day continuous surface-kinematics model for the entire Latin American and Caribbean region (VEMOS2017). VEMOS2017 was derived from pointwise station velocities inferred at 515 geodetic sites from January 1, 2014 to January 28, 2017 using a geodetic least-squares collocation approach with empirically determined covariance functions. VEMOS2017 describes the present-day deformation in Latin America and the Caribbean and continues the surface-kinematics model represented by VEMOS2015, which is valid from March 14, 2010 to April 11, 2015 (see doi:10.1594/PANGAEA.863132). VEMOS2017 covers the region from 120°W, 55°S to 35°W, 32°N with a spatial resolution of 1° x 1°. The average uncertainty of VEMOS2017 is assessed to be ±1.0 mm/a in the north-south direction and ±1.7 mm/a in the east-west direction. The maximum uncertainty values (up to ±15 mm/a) occur at the zones affected by recent strong earthquakes (in the Maule area, the northern part of Chile, Ecuador and Costa Rica). The best uncertainty values (about ±0.1 mm/a) result in the stable eastern part of the South American plate. Category: geoscientificInformation Source: Not Available Supplemental Information: Datasets listed in this Collection: - VMS2017.GRD: Velocity model for SIRGAS 2017 referring to the IGS14 (ITRF2014) - VMS2017CA.GRD: Velocity model for SIRGAS 2017 relative to the Caribbean plate - VMS2017SA.GRD: Velocity model for SIRGAS 2017 relative to the South American plate. Coverage: EVENT LABEL: * LATITUDE START: -11.500000 * LONGITUDE START: -77.500000 * LATITUDE END: -55.000000 * LONGITUDE END: -35.000000 * DATE/TIME START: 2014-01-01T00:00:00 * DATE/TIME END: 2017-01-28T00:00:00 * METHOD/DEVICE: modelled
Data Types:
  • Dataset
  • File Set
Abstract: The SIRGAS reference frame realization (SIR17P01) covers the period from April 17, 2011 (GPS week 1632) to January 28, 2017 (GPS week 1933). It includes only weekly solutions referring to the IGS08/IGb08 reference frame. This new SIRGAS realization is aligned to the IGS14 reference frame and it is consistent with the igs14.atx ground antenna calibrations. SIR17P01 includes positions and velocities of 345 stations referring tothe IGS14, epoch 2015.0. Its estimated precision is ±1.2 mm (horizontal) and ±2.5 mm (vertical) for the station positions at the reference epoch, and ±0.7 mm/a (horizontal) and ±1.1 mm/a (vertical)for the velocities. Category: geoscientificInformation Source: Not Available Supplemental Information: Datasets listed in this Collection: - SIR17P01.SNX: Station positions and velocities in SINEX (Solution (Software/technique) INdependent Exchange) format - SIR17P01_XYZ.CRD: geocentric Cartesian station positions - SIR17P01_XYZ.VEL: geocentric Cartesian station velocities - SIR17P01_NEH.CRD: ellipsoidal station positions - SIR17P01_NEH.VEL: ellipsoidal station velocities Coverage: EVENT LABEL: * LATITUDE START: -55.000000 * LONGITUDE START: -120.000000 * LATITUDE END: 32.000000 * LONGITUDE END: -35.000000 * DATE/TIME START: 2011-04-17T00:00:00 * DATE/TIME END: 2017-01-28T00:00:00 * METHOD/DEVICE: modelled
Data Types:
  • Dataset
  • File Set