nasdi/standardized_precipitation

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Service Description: The Standardized Precipitation Index (SPI) is widely regarded as one of the most accessible tools for quantifying and reporting meteorological drought. At shorter timescales, SPI values are highly correlated with soil moisture, while at extended timescales, they reflect variations in groundwater and reservoir storage. The SPI model derives probability distributions from historical precipitation records, which are then normalized using an incomplete gamma function across multiple timescales. SPI values indicate the number of standard deviations the observed anomaly departs from the long-term period of record, with positive values corresponding to wetter-than-average conditions. These values are intended to provide an overall assessment of agricultural growing conditions within a region for a specified time period. On the monthly scale, time periods calculated are 1, 2, 3, 6, 9, 12, 18, 24 months. On the weekly scale, each ISO week is numbered from 1 to 52 (sometimes 53) within a year. An ISO week starts on Monday and ends on Sunday. The time periods can be filtered using the tType field in the service where a suffix "m" denotes a monthly time scale and "w" denotes a weekly time scale. Historical record goes back to 1980. Indices values were calculated using the xclim python package. For more information, visit: https://open.canada.ca/data/en/dataset/cdc59a23-ca37-4645-b96d-4e7737404e54

Name: nasdi/standardized_precipitation_index

Description: The Standardized Precipitation Index (SPI) is widely regarded as one of the most accessible tools for quantifying and reporting meteorological drought. At shorter timescales, SPI values are highly correlated with soil moisture, while at extended timescales, they reflect variations in groundwater and reservoir storage. The SPI model derives probability distributions from historical precipitation records, which are then normalized using an incomplete gamma function across multiple timescales. SPI values indicate the number of standard deviations the observed anomaly departs from the long-term period of record, with positive values corresponding to wetter-than-average conditions. These values are intended to provide an overall assessment of agricultural growing conditions within a region for a specified time period. On the monthly scale, time periods calculated are 1, 2, 3, 6, 9, 12, 18, 24 months. On the weekly scale, each ISO week is numbered from 1 to 52 (sometimes 53) within a year. An ISO week starts on Monday and ends on Sunday. The time periods can be filtered using the tType field in the service where a suffix "m" denotes a monthly time scale and "w" denotes a weekly time scale. Historical record goes back to 1980. Indices values were calculated using the xclim python package. For more information, visit: https://open.canada.ca/data/en/dataset/cdc59a23-ca37-4645-b96d-4e7737404e54

Single Fused Map Cache: false

Extent:

Initial Extent:

Full Extent:

Time Info:

[2015/01/11 12:00:00 UTC, 2026/04/26 12:00:00 UTC]

Pixel Size X: 20377.28883405864

Pixel Size Y: 20377.288834058636

Band Count: 1

Pixel Type: F32

RasterFunction Infos: {"rasterFunctionInfos": [ { "name": "nasdi_standardized_precipitation_index", "description": "Standardized precipitation index (SPI)", "help": "" }, { "name": "None", "description": "Make a Raster or Raster Dataset into a Function Raster Dataset.", "help": "" } ]}

Mensuration Capabilities: Basic

Has Histograms: false

Has Colormap: false

Has Multi Dimensions : false

Rendering Rule:

Min Scale: 0

Max Scale: 0

Copyright Text: Agriculture and Agri-Food Canada

Service Data Type: esriImageServiceDataTypeGeneric

Min Values: N/A

Max Values: N/A

Mean Values: N/A

Standard Deviation Values: N/A

Object ID Field: OBJECTID

Fields:

OBJECTID ( type: esriFieldTypeOID, alias: OBJECTID )
Shape ( type: esriFieldTypeGeometry, alias: Shape )
Name ( type: esriFieldTypeString, alias: Name, length: 200 )
MinPS ( type: esriFieldTypeDouble, alias: MinPS )
MaxPS ( type: esriFieldTypeDouble, alias: MaxPS )
LowPS ( type: esriFieldTypeDouble, alias: LowPS )
HighPS ( type: esriFieldTypeDouble, alias: HighPS )
Category ( type: esriFieldTypeInteger, alias: Category , Coded Values: [0: Unknown] , [1: Primary] , [2: Overview] , ...6 more... )
Tag ( type: esriFieldTypeString, alias: Tag, length: 100 )
GroupName ( type: esriFieldTypeString, alias: GroupName, length: 100 )
ProductName ( type: esriFieldTypeString, alias: ProductName, length: 100 )
CenterX ( type: esriFieldTypeDouble, alias: CenterX )
CenterY ( type: esriFieldTypeDouble, alias: CenterY )
ZOrder ( type: esriFieldTypeInteger, alias: ZOrder )
Shape_Length ( type: esriFieldTypeDouble, alias: Shape_Length )
Shape_Area ( type: esriFieldTypeDouble, alias: Shape_Area )
dateEnd ( type: esriFieldTypeDate, alias: dateEnd, length: 8 )
tType ( type: esriFieldTypeString, alias: tType, length: 30 )

Default Mosaic Method: ByAttribute

Allowed Mosaic Methods: ByAttribute,None,LockRaster

SortField: dateEnd

SortValue: 3000

Mosaic Operator: First

Default Compression Quality: 75

Default Resampling Method: Bilinear

Max Record Count: 1000

Max Image Height: 4100

Max Image Width: 15000

Max Download Image Count: 20

Max Mosaic Image Count: 1

Allow Raster Function: true

Allow Copy: true

Allow Analysis: true

Allow Compute TiePoints: false

Supports Statistics: true

Supports Advanced Queries: true

Use StandardizedQueries: true

Raster Type Infos:

Has Raster Attribute Table: false

Edit Fields Info: null

Ownership Based AccessControl For Rasters: null

Child Resources: Info Statistics Key Properties Legend Raster Function Infos

Supported Operations: Export Image Query Identify Measure Compute Histograms Compute Statistics Histograms Get Samples Compute Class Statistics Query Boundary Compute Pixel Location Compute Angles Validate Project

nasdi/standardized_precipitation_index (ImageServer)