Metadata:
  Identification_Information:
    Citation:
      Citation_Information:
        Originator: Peter G. Chirico
        Originator: Jessica D. DeWitt
        Originator: Sarah E. Bergstresser
        Originator: Inga E. Clark
        Publication_Date: 2018
        Title: The Central African Republic Diamond Database (2018) - Recent (2013-2017) Mining Activity Dataset
        Geospatial_Data_Presentation_Form: GIS data
        Publication_Information:
          Publication_Place: Reston, VA
          Publisher: U.S. Geological Survey
        Online_Linkage: https://doi.org/10.5066/F7GF0SDB
        Larger_Work_Citation:
          Citation_Information:
            Originator: Jessica D. DeWitt
            Originator: Peter G. Chirico
            Originator: Sarah E. Bergstresser
            Originator: Inga E. Clark
            Publication_Date: 2018
            Title: The Central African Republic Diamond Database – A Geodatabase of Archival Diamond Occurrences and Areas of Recent Artisanal and Small-scale Diamond Mining
            Geospatial_Data_Presentation_Form: On File Report
            Publication_Information:
              Publication_Place: Reston, VA
              Publisher: U.S. Geological Survey
    Description:
      Abstract: 894 very-high resolution satellite images were acquired between January 2013 and December of 2016, covering nearly 60,000 km2 of the country. Of this total, 49% (437 images) were acquired for the Western CAR region and cover approximately half of the Carnot sandstone area (43,097 km2). The remaining 51% (457 images) cover specific parts of the Eastern CAR region, including several areas of the Mouka-Ouadda sandstone (26,540 km2). The acquired imagery was collected on 97 different dates between 2013 and 2017, with the majority of these dates occurring from 2015-2017. Interpretation of ASM activity was based on indicators of mining activity suggested in Chirico and Malpeli (2013) and Kauffman and others (2015). In the dataset published here, if any imagery indicators of mining activity were observed, including bright soil indicating excavation activity, a lack of vegetation surrounding the immediate area, sharp angularity in the sides of the pit, or the presence of turbid water in a pit, the site was considered active. The presence of multiple active mine sites within 1 square kilometer is recorded as an attribute with each point. The type of mining activity (whether generic, excavation, washing, or previously active) is also recorded in the attributes of each point. It should be noted that this dataset is not an exhaustive record of mining activity in CAR -- it is possible that there are artisanal mine sites beyond the extent of these points, however the dataset is complete to the extent of the satellite imagery and fieldwork observations available at this time. Additional information regarding the coverage of imagery, the methods of interpretation, and specific findings can be found in the Open-File Report that publishes this and associated datasets (DeWitt and others, 2018).
      Purpose: The purpose of this dataset is to catalog the geographic areas of active small-scale and artisanal diamond mining sites in the Central African Republic that have been interpreted from very high resolution (VHR) satellite imagery between the dates of January 1, 2013 and November 29, 2017.
      Supplemental_Information: A second dataset, titled "The Central African Republic Diamond Database (2018) - Archival ASM and Diamond Occurrences Dataset" is closely associated with this dataset, and should also be used in describing the geographic distribution of CAR's diamond resources
    Time_Period_of_Content:
      Time_Period_Information:
        Range_of_Dates/Times:
          Beginning_Date: 2013
          Ending_Date: 2017
      Currentness_Reference: ground condition
    Status:
      Progress: Complete
      Maintenance_and_Update_Frequency: None planned
    Spatial_Domain:
      Bounding_Coordinates:
        West_Bounding_Coordinate: 14.414062495844
        East_Bounding_Coordinate: 27.421874995324
        North_Bounding_Coordinate: 11.070173525592
        South_Bounding_Coordinate: 2.3499775496997
    Keywords:
      Theme:
        Theme_Keyword_Thesaurus: USGS Thesaurus
        Theme_Keyword: gem resources
        Theme_Keyword: placer deposit mining
      Theme:
        Theme_Keyword_Thesaurus: CommonGeographicAreas
        Theme_Keyword: Central African Republic
      Theme:
        Theme_Keyword_Thesaurus: LithClass6.2
        Theme_Keyword: Alluvium
      Place:
        Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
        Place_Keyword: Central African Republic
    Access_Constraints: none
    Use_Constraints: Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research.
    Point_of_Contact:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Peter G. Chirico
          Contact_Organization: U.S. Geological Survey
        Contact_Address:
          Address_Type: mailing and physical
          Address: 12201 Sunrise Valley Dr.
          City: Reston
          State_or_Province: VA
          Postal_Code: 20192
          Country: USA
        Contact_Voice_Telephone: 703-648-6950
        Contact_Electronic_Mail_Address: pchirico@usgs.gov
    Data_Set_Credit: U.S. Department of State, U.S. Agency for International Development
    Cross_Reference:
      Citation_Information:
        Originator: Jessica D. DeWitt
        Originator: Peter G. Chirico
        Originator: Sarah E. Bergstresser
        Originator: Inga E. Clark
        Publication_Date: 2018
        Title: The Central African Republic Diamond Database – A Geodatabase of Archival Diamond Occurrences and Areas of Recent Artisanal and Small-scale Diamond Mining
        Publication_Information:
          Publication_Place: Reston, VA
          Publisher: U.S. Geological Survey
  Data_Quality_Information:
    Attribute_Accuracy:
      Attribute_Accuracy_Report: The accuracy of the mining interpretation within the Carnot region was assessed through comparison to field data collected by the U.S. Agency for International Development (USAID)’s Property Rights and Artisanal Diamond Development II (PRADD II) project. Between August 1, 2016 and January 30, 2017 the PRADD II project staff visited and mapped many artisanal mining sites throughout the Carnot region. Of the 262 points independently collected by this mapping endeavor, 65 field sites fell within or immediately adjacent to gridcells selected as suitable for current mining in the Recent Mining Activities Dataset and were used to assess the dataset’s accuracy (Figure 5). The comparison of these field observations with the Recent Mining Dataset is done using a confusion matrix. The Recent (2013-2016) Mining activity dataset was found to have an overall accuracy of 75% when compared to field observations collected by the PRADD II project. For more details regarding the accuracy assessment of this dataset, see DeWitt and others (2017).
    Logical_Consistency_Report: No formal logical accuracy tests were conducted
    Completeness_Report: Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
    Positional_Accuracy:
      Horizontal_Positional_Accuracy:
        Horizontal_Positional_Accuracy_Report: No formal positional accuracy tests were conducted
      Vertical_Positional_Accuracy:
        Vertical_Positional_Accuracy_Report: No formal positional accuracy tests were conducted
    Lineage:
      Process_Step:
        Process_Description: The Central African Republic - Archival Diamond Occurrence Dataset was used to identify geographic areas known for diamond mining activity within CAR. The extent of these sites were then designated as areas of interest, and analyzed through manual interpretation of high resolution satellite imagery to identify areas of recent mining activity. Very high resolution (VHR) satellite imagery with a ground sampling distance (GSD) of 2 m2 or less was acquired between January 1, 2015 and March 15, 2016. Although the entirety of the Carnot and Mouka-Ouadda focus areas were not able to be covered by VHR satellite imagery, areas known to be diamondiferous (particularly within the Mouka-Ouadda) were identified and prioritized using the Archival Diamond Occurrence dataset. Indicators used to visually interpret recent diamond mining activity from satellite imagery consisted of: the brightness of soil surrounding pits that indicate excavation activity, sharp angularity of pit edges indicating benching or recent excavation, the absence of vegetation surrounding the immediate area of the pit, and the presence and color of water in a pit. Additional details about satellite interpretation specific to the Carnot or the Mouka-Ouadda regions are provided in DeWitt and others (2017).  Sites interpreted as having recent (2013-2016) mining activity were joined to a grid of 1 square kilometer (1 km2) polygons, and only gridcells containing points were kept in the Recent (2013-2016) Mining Activity Dataset. Thus each point in this dataset describes the centroid of a 1 square kilometer (1 km2) area, which contains one or more active small-scale mining sites. Where multiple mining activity types were present within a single cell, the cell was given the ASM_Value of 1 to generically indicate that mining activity was present.
        Process_Date: 2016
  Spatial_Data_Organization_Information:
    Direct_Spatial_Reference_Method: Point
  Spatial_Reference_Information:
    Horizontal_Coordinate_System_Definition:
      Planar:
        Map_Projection:
          Map_Projection_Name: Transverse Mercator
          Transverse_Mercator:
            Scale_Factor_at_Central_Meridian: 0.9996
            Longitude_of_Central_Meridian: 21.0
            Latitude_of_Projection_Origin: 0.0
            False_Easting: 500000.0
            False_Northing: 0.0
        Planar_Coordinate_Information:
          Planar_Coordinate_Encoding_Method: coordinate pair
          Coordinate_Representation:
            Abscissa_Resolution: 10.0
            Ordinate_Resolution: 10.0
          Planar_Distance_Units: METERS
      Geodetic_Model:
        Horizontal_Datum_Name: D_WGS_1984
        Ellipsoid_Name: WGS 1984
        Semi-major_Axis: 6378137.0
        Denominator_of_Flattening_Ratio: 298.257223563
  Entity_and_Attribute_Information:
    Detailed_Description:
      Entity_Type:
        Entity_Type_Label: Recent_mining_1km2_areas_2013_2016
        Entity_Type_Definition: locations of ASM activity interpreted from high resolution satellite imagery
        Entity_Type_Definition_Source: USGS Artisanal Diamonds Project
      Attribute:
        Attribute_Label: OBJECTID
        Attribute_Definition: Unique identification number for each point record
        Attribute_Definition_Source: Automatically populated by ESRI ArcGIS 10.4
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 1
            Range_Domain_Maximum: 1815
      Attribute:
        Attribute_Label: Shape
        Attribute_Definition: Geometry of the GIS data record
        Attribute_Definition_Source: ESRI ArcGIS 10.4
        Attribute_Domain_Values:
          Unrepresentable_Domain: All records in this dataset are 'point' shapes.
      Attribute:
        Attribute_Label: ASM_Val
        Attribute_Definition: Type of artisanal and small-scale mining (ASM) activity observed in satellite imagery at a mine site.
        Attribute_Definition_Source: USGS Artisanal Diamonds Project
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 1
            Enumerated_Domain_Value_Definition: Site has mining activity (generic)
            Enumerated_Domain_Value_Definition_Source: USGS Artisanal Diamonds Project
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 2
            Enumerated_Domain_Value_Definition: Primarily excavation activity (signs of active digging, including benching, angular pit sides, and spoil piles)
            Enumerated_Domain_Value_Definition_Source: USGS Artisanal Diamonds Project
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 3
            Enumerated_Domain_Value_Definition: Washing of gravel material in pits or other nearby water body
            Enumerated_Domain_Value_Definition_Source: USGS Artisanal Diamonds Project
        Attribute_Domain_Values:
          Enumerated_Domain:
            Enumerated_Domain_Value: 5
            Enumerated_Domain_Value_Definition: Site is currently inactive based on image indicators (see DeWitt and others, 2017), but exhibits signs of previous mining activity
            Enumerated_Domain_Value_Definition_Source: USGS Artisanal Diamonds Project
      Attribute:
        Attribute_Label: Obs_Yr
        Attribute_Definition: Year of satellite image acquisition, from which ASM activity was interpreted.
        Attribute_Definition_Source: USGS Artisanal Diamonds Project
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 2013
            Range_Domain_Maximum: 2016
            Attribute_Units_of_Measure: year
      Attribute:
        Attribute_Label: Num_Obs
        Attribute_Definition: Number of ASM activity observations (each indicating an individual ASM pit or mine site) within the 1 square kilometer area indicated by each record, for all the years of observation
        Attribute_Definition_Source: USGS Artisanal Diamonds Project
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 1
            Range_Domain_Maximum: 54
            Attribute_Units_of_Measure: observation
      Attribute:
        Attribute_Label: Latitude
        Attribute_Definition: Y coordinate, in decimal degrees of WGS 84, for the point record's location
        Attribute_Definition_Source: WGS 84
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 3.117499
            Range_Domain_Maximum: 8.785728
            Attribute_Units_of_Measure: decimal degrees
      Attribute:
        Attribute_Label: Longitude
        Attribute_Definition: X coordinate, in decimal degrees of WGS 84, for the point record's location
        Attribute_Definition_Source: WGS 84
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 15.20009
            Range_Domain_Maximum: 23.42385
            Attribute_Units_of_Measure: decimal degrees
      Attribute:
        Attribute_Label: N_UTM34N
        Attribute_Definition: Northing coordinate for the point record's location, in meters, UTM 34 N WGS 84
        Attribute_Definition_Source: UTM 34N WGS 84
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 345934.3
            Range_Domain_Maximum: 971934.3
            Attribute_Units_of_Measure: meters
      Attribute:
        Attribute_Label: E_UTM34N
        Attribute_Definition: Easting coordinate for the point record's location, in meters, UTM 34 N WGS 84
        Attribute_Definition_Source: UTM 34N WGS 84
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: -144751.6
            Range_Domain_Maximum: 767248.4
            Attribute_Units_of_Measure: meters
  Distribution_Information:
    Distributor:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Peter G. Chirico
          Contact_Organization: U.S. Geological Survey
        Contact_Address:
          Address_Type: mailing and physical
          Address: 12201 Sunrise Valley Dr.
          City: Reston
          State_or_Province: VA
          Postal_Code: 20192
          Country: USA
        Contact_Voice_Telephone: 703-648-6950
        Contact_Electronic_Mail_Address: pchirico@usgs.gov
    Distribution_Liability: Public domain data from the U.S. Government are freely distributable with proper metadata and source attribution. The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research.
    Technical_Prerequisites: This dataset is formatted as a feature class in an ESRI geodatabase. It requires the user to have geospatial software such as ESRI ArcGIS, Blue Marble Global Mapper, Que GIS, GRASS, or other GIS software.
  Metadata_Reference_Information:
    Metadata_Date: 20180405
    Metadata_Contact:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Peter G. Chirico
          Contact_Organization: U.S. Geological Survey
        Contact_Address:
          Address_Type: mailing and physical
          Address: 12201 Sunrise Valley Dr.
          City: Reston
          State_or_Province: VA
          Postal_Code: 20192
          Country: USA
        Contact_Voice_Telephone: 703-648-6950
        Contact_Electronic_Mail_Address: pchirico@usgs.gov
    Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
    Metadata_Standard_Version: FGDC-STD-001-1998
