SLC Version 3.1 dataset and usage

SLC version 3.1(SLCv3.1) dataset is composed of line work, line attribute table, SLCv3.1 Component (CMP) Table, soil name file (SNF) and soil layer file (SLF). The line work is provided as ESRI E00 or Shape file with either Geographic or Lambert Conformal Conic (LCC) projection using the NAD83 earth model. The CMP, SNF and SLF are distributed as DBF file. More detailed specifications of the SLCv3.1 data compilation and data model are documented in the CanSIS web site.

SLCv3.1 data set is organized as both provincial and on national entities. The national mosaics of SNF and SLF are simply the concatenation of the individual province files. However due to some cross border polygons, the national SLCv3.1 CMP table is mosaiced after Area Weighted Correlation process. The Percent values of those cross border polygons will be different from the ones in the original CMP tables. However the total of component percentage should add up to 100% (+/-2% due to rounding). The order of the values, of the Component field, of the cross border polygons, has not been rearranged after the correlation.

According to the SLCv3 specification, a linkage named SOILTYPE has been constructed for the CMP, SNF and SLF. The original definition of the SOILTYPE is: SOILTYPE = PROVINCE+SOIL_CODE+MODIFIER+LU

However there is no such information as LU available in the CMP table. The SLCv3 Task Advisory Group (TAG) decided to construct the linkage using: SOILTYPE=PROVINCE+SOIL_CODE+MODIFIER. Also due to the unused space(s) of the MODIFIER field, the TAG suggested to use "_" to replace the empty space of the MODIFIER values wherever happens. It is up to users to refine the linking 
according to their need. For example, a user can pre-select records with LU = "A" from the SNF and conduct join or relate between the CMP and SNF after. However due to the nature of this version of
SLC, the linkage between the CMP and SNF and SLF should be agricultural land based. Any attemp to link the CMP to the SNF or SLF without using agricultural soil records may produce misleading oucomes.      
   
SLC version 3.1 dataset compilation includes several stages: 

1. SLCv3 line work adjustments, editing and SL numbering. The line work was created using the latest national hydro-base. The final line work has geographic in decimal degree (DD) and Lambert Conformal Conic (LCC) projection. The data line-work can be distributed as ESRI E00 or shape file format. Provincial coverages are also available. For more details please contact: 
Andre, Villeneuve 

2. SLCv3 component table design, creation, population, and validation. The component table is defined with 26 fields. For more details about the table 
definition, please visit SLC Component Table page. The first 9 of the 26 fields are populated by using integration of detailed soil survey (DSS) data under each SLC v3 polygon. Software tools have been developed for this work. The tools have been distributed to every province, and are still available through 
CanSIS. Contact Xiaoyuan Geng.  Validation of the contents of the 9 fields is done with CTS check tool developed by Glenn Lelyk. 

The rest of the 17 fields are populated by using standardized soil name file (SNF) and soil layer file (SLF). The algorithms and software tools are available through CanSIS. For more information please contact Xiaoyuan Geng at 613-759-1895.  

3. SLC v3 component table validation and correction. Component table validation and correction is part of data compilation cycle. It is conducted whenever and where ever there is such need. 

4. SLC v3 cross border polygon mapping and component table correlation.  Provincial boundaries create artificial segmentation of the SLC v3 polygons. For some provinces, the SLC components of the cross border polygons need to be adjusted or correlated before the final merge. Three possible correlation methods have been proposed and implemented (except the online editing option). 
   
The methods are: 
                a. Simple component records blending 
                b. Area weighted records blending and recoding 
                c. Manual expert based online editing  
Again the software tools for the cross border polygon visualization and correlation are available through CanSIS. Please contact Xiaoyuan Geng for more details. 

5. SLC v3 component table mosaicing. For national coverage and component table, append the correlated provincial component tables is required. Software tool for this work has been developed. Contact Xiaoyuan Geng.

6. SLC v3 archiving and distribution. SLC v3 data will be uploaded into NSDB, SDE and Oracle environment. As well as the conventional distribution approach, the SLC v3 related attributes will be distributed through Web Mapping and Geolinking methods.