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title

📍 Fast, Accurate Python library for Raster Operations

⚡ Extensible with Numba

⏩ Scalable with Dask

🎊 Free of GDAL / GEOS Dependencies

🌍 General-Purpose Spatial Processing, Geared Towards GIS Professionals


Xarray-Spatial implements common raster analysis functions using Numba and provides an easy-to-install, easy-to-extend codebase for raster analysis.

Installation

# via pip
pip install xarray-spatial

# via conda
conda install -c conda-forge xarray-spatial

Downloading our starter examples and data

Once you have xarray-spatial installed in your environment, you can use one of the following in your terminal (with the environment active) to download our examples and/or sample data into your local directory.

xrspatial examples : Download the examples notebooks and the data used.

xrspatial copy-examples : Download the examples notebooks but not the data. Note: you won't be able to run many of the examples.

xrspatial fetch-data : Download just the data and not the notebooks.

In all the above, the command will download and store the files into your current directory inside a folder named 'xrspatial-examples'.

xarray-spatial grew out of the Datashader project, which provides fast rasterization of vector data (points, lines, polygons, meshes, and rasters) for use with xarray-spatial.

xarray-spatial does not depend on GDAL / GEOS, which makes it fully extensible in Python but does limit the breadth of operations that can be covered. xarray-spatial is meant to include the core raster-analysis functions needed for GIS developers / analysts, implemented independently of the non-Python geo stack.

Our documentation is still under construction, but docs can be found here.

Raster-huh?

Rasters are regularly gridded datasets like GeoTIFFs, JPGs, and PNGs.

In the GIS world, rasters are used for representing continuous phenomena (e.g. elevation, rainfall, distance), either directly as numerical values, or as RGB images created for humans to view. Rasters typically have two spatial dimensions, but may have any number of other dimensions (time, type of measurement, etc.)

Supported Spatial Functions with Supported Inputs

✅ = native backend    🔄 = accepted (CPU fallback)

Classification · Diffusion · Focal · Morphological · Fire · Multispectral · Multivariate · Pathfinding · Proximity · Reproject / Merge · Raster / Vector Conversion · Surface · Hydrology · Flood · Interpolation · Dasymetric · Zonal · Utilities


GeoTIFF / COG I/O

Native GeoTIFF and Cloud Optimized GeoTIFF reader/writer. No GDAL required.

Name Description NumPy Dask CuPy GPU Dask+CuPy GPU Cloud
read_geotiff Read GeoTIFF / COG / VRT ✅️ ✅️ ✅️ ✅️ ✅️
write_geotiff Write DataArray as GeoTIFF / COG ✅️ ✅️ ✅️ ✅️ ✅️
write_vrt Generate VRT mosaic from GeoTIFFs ✅️

read_geotiff and write_geotiff auto-dispatch to the correct backend:

read_geotiff('dem.tif')                              # NumPy
read_geotiff('dem.tif', chunks=512)                  # Dask
read_geotiff('dem.tif', gpu=True)                    # CuPy (nvCOMP + GDS)
read_geotiff('dem.tif', gpu=True, chunks=512)        # Dask + CuPy
read_geotiff('https://example.com/cog.tif')          # HTTP COG
read_geotiff('s3://bucket/dem.tif')                  # Cloud (S3/GCS/Azure)
read_geotiff('mosaic.vrt')                           # VRT mosaic (auto-detected)

write_geotiff(cupy_array, 'out.tif')                 # auto-detects GPU
write_geotiff(data, 'out.tif', gpu=True)             # force GPU compress
write_vrt('mosaic.vrt', ['tile1.tif', 'tile2.tif'])  # generate VRT

Compression codecs: Deflate, LZW (Numba JIT), ZSTD, PackBits, JPEG (Pillow), uncompressed

GPU codecs: Deflate and ZSTD via nvCOMP batch API; LZW via Numba CUDA kernels

Features:

  • Tiled, stripped, BigTIFF, multi-band (RGB/RGBA), sub-byte (1/2/4/12-bit)
  • Predictors: horizontal differencing (pred=2), floating-point (pred=3)
  • GeoKeys: EPSG, WKT/PROJ (via pyproj), citations, units, ellipsoid, vertical CRS
  • Metadata: nodata masking, palette colormaps, DPI/resolution, GDALMetadata XML, arbitrary tag preservation
  • Cloud storage: S3 (s3://), GCS (gs://), Azure (az://) via fsspec
  • GPUDirect Storage: SSD→GPU direct DMA via KvikIO (optional)
  • Thread-safe mmap reads, atomic writes, HTTP connection reuse (urllib3)
  • Overview generation: mean, nearest, min, max, median, mode, cubic
  • Planar config, big-endian byte swap, PixelIsArea/PixelIsPoint

Read performance (real-world files, A6000 GPU):

File Format xrspatial CPU rioxarray GPU (nvCOMP)
render_demo 187x253 uncompressed 0.2ms 2.4ms 0.7ms
Landsat B4 1310x1093 uncompressed 1.0ms 6.0ms 1.7ms
Copernicus 3600x3600 deflate+fp3 241ms 195ms 872ms
USGS 1as 3612x3612 LZW+fp3 275ms 215ms 747ms
USGS 1m 10012x10012 LZW 1.25s 1.80s 990ms

Read performance (synthetic tiled, GPU shines at scale):

Size Codec xrspatial CPU rioxarray GPU (nvCOMP)
4096x4096 deflate 265ms 211ms 158ms
4096x4096 zstd 73ms 159ms 58ms
8192x8192 deflate 1.06s 859ms 565ms
8192x8192 zstd 288ms 668ms 171ms

Write performance (synthetic tiled):

Size Codec xrspatial CPU rioxarray GPU (nvCOMP)
2048x2048 deflate 424ms 110ms 135ms
2048x2048 zstd 49ms 83ms 81ms
4096x4096 deflate 1.68s 447ms 302ms
8192x8192 deflate 6.84s 2.03s 1.11s
8192x8192 zstd 847ms 822ms 1.03s

Consistency: 100% pixel-exact match vs rioxarray on all tested files (Landsat 8, Copernicus DEM, USGS 1-arc-second, USGS 1-meter).


Reproject / Merge

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Reproject Reprojects a raster to a new CRS using an approximate transform and numba JIT resampling Standard (inverse mapping) ✅️ ✅️ ✅️ ✅️
Merge Merges multiple rasters into a single mosaic with configurable overlap strategy Standard (mosaic) ✅️ ✅️ 🔄 🔄

Utilities

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Preview Downsamples a raster to target pixel dimensions for visualization Custom ✅️ ✅️ ✅️ 🔄
Rescale Min-max normalization to a target range (default [0, 1]) Standard ✅️ ✅️ ✅️ ✅️
Standardize Z-score normalization (subtract mean, divide by std) Standard ✅️ ✅️ ✅️ ✅️

Surface

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Aspect Computes downslope direction of each cell in degrees Horn 1981 ✅️ ✅️ ✅️ ✅️
Northness North-south component of aspect: cos(aspect) for linear models Stage 1976 ✅️ ✅️ ✅️ ✅️
Eastness East-west component of aspect: sin(aspect) for linear models Stage 1976 ✅️ ✅️ ✅️ ✅️
Curvature Measures rate of slope change (concavity/convexity) at each cell Zevenbergen & Thorne 1987 ✅️ ✅️ ✅️ ✅️
Hillshade Simulates terrain illumination from a given sun angle and azimuth GDAL gdaldem ✅️ ✅️ ✅️ ✅️
Roughness Computes local relief as max minus min elevation in a 3×3 window GDAL gdaldem ✅️ ✅️ ✅️ ✅️
Sky-View Factor Measures the fraction of visible sky hemisphere at each cell Zakek et al. 2011 ✅️ ✅️ ✅️ ✅️
Slope Computes terrain gradient steepness at each cell in degrees Horn 1981 ✅️ ✅️ ✅️ ✅️
Terrain Generation Generates synthetic terrain from fBm or ridged fractal noise with optional domain warping, Worley blending, and hydraulic erosion Custom (fBm) ✅️ ✅️ ✅️ ✅️
TPI Computes Topographic Position Index (center minus mean of neighbors) Weiss 2001 ✅️ ✅️ ✅️ ✅️
TRI Computes Terrain Ruggedness Index (local elevation variation) Riley et al. 1999 ✅️ ✅️ ✅️ ✅️
Landforms Classifies terrain into 10 landform types using the Weiss (2001) TPI scheme Weiss 2001 ✅️ ✅️ ✅️ ✅️
Viewshed Determines visible cells from a given observer point on terrain GRASS GIS r.viewshed ✅️ ✅️ ✅️ ✅️
Min Observable Height Finds the minimum observer height needed to see each cell (experimental) Custom ✅️
Perlin Noise Generates smooth continuous random noise for procedural textures Perlin 1985 ✅️ ✅️ ✅️ ✅️
Worley Noise Generates cellular (Voronoi) noise returning distance to the nearest feature point Worley 1996 ✅️ ✅️ ✅️ ✅️
Hydraulic Erosion Simulates particle-based water erosion to carve valleys and deposit sediment Custom ✅️ ✅️ ✅️ ✅️
Bump Mapping Adds randomized bump features to simulate natural terrain variation Custom ✅️ ✅️ ✅️ ✅️

Hydrology

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Flow Direction (D8) Computes D8 flow direction from each cell toward the steepest downhill neighbor O'Callaghan & Mark 1984 ✅️ ✅️ ✅️ ✅️
Flow Direction (Dinf) Computes D-infinity flow direction as a continuous angle toward the steepest downslope facet Tarboton 1997 ✅️ ✅️ ✅️ ✅️
Flow Direction (MFD) Partitions flow to all downslope neighbors with an adaptive exponent (Qin et al. 2007) Qin et al. 2007 ✅️ ✅️ ✅️ ✅️
Flow Accumulation (D8) Counts upstream cells draining through each cell in a D8 flow direction grid Jenson & Domingue 1988 ✅️ ✅️ ✅️ ✅️
Flow Accumulation (Dinf) Accumulates upstream area by splitting flow proportionally between two neighbors (Tarboton 1997) Tarboton 1997 ✅️ ✅️ ✅️ 🔄
Flow Accumulation (MFD) Accumulates upstream area through all MFD flow paths weighted by directional fractions Qin et al. 2007 ✅️ ✅️ ✅️ 🔄
Flow Length (D8) Computes D8 flow path length from each cell to outlet (downstream) or from divide (upstream) Standard (D8 tracing) ✅️ ✅️ ✅️ 🔄
Flow Length (Dinf) Proportion-weighted flow path length using D-inf angle decomposition (downstream or upstream) Tarboton 1997 ✅️ ✅️ ✅️ 🔄
Flow Length (MFD) Proportion-weighted flow path length using MFD fractions (downstream or upstream) Qin et al. 2007 ✅️ ✅️ ✅️ 🔄
Watershed Labels each cell with the pour point it drains to via D8 flow direction Standard (D8 tracing) ✅️ ✅️ ✅️ ✅️
Basins Delineates drainage basins by labeling each cell with its outlet ID Standard (D8 tracing) ✅️ ✅️ ✅️ ✅️
Stream Order Assigns Strahler or Shreve stream order to cells in a drainage network Strahler 1957, Shreve 1966 ✅️ ✅️ ✅️ ✅️
Stream Order (Dinf) Strahler/Shreve stream ordering on D-infinity flow direction grids Tarboton 1997 ✅️ ✅️ ✅️ ✅️
Stream Order (MFD) Strahler/Shreve stream ordering on MFD fraction grids Freeman 1991 ✅️ ✅️ ✅️ ✅️
Stream Link Assigns unique IDs to each stream segment between junctions Standard ✅️ ✅️ ✅️ ✅️
Stream Link (Dinf) Stream link segmentation on D-infinity flow direction grids Tarboton 1997 ✅️ ✅️ ✅️ ✅️
Stream Link (MFD) Stream link segmentation on MFD fraction grids Freeman 1991 ✅️ ✅️ ✅️ ✅️
Snap Pour Point Snaps pour points to the highest-accumulation cell within a search radius Custom ✅️ ✅️ ✅️ ✅️
Flow Path Traces downstream flow paths from start points through a D8 direction grid Standard (D8 tracing) ✅️ ✅️ 🔄 🔄
HAND Computes Height Above Nearest Drainage by tracing D8 flow to the nearest stream cell Nobre et al. 2011 ✅️ ✅️ 🔄 🔄
TWI Topographic Wetness Index: ln(specific catchment area / tan(slope)) Beven & Kirkby 1979 ✅️ ✅️ ✅️ 🔄

Flood

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Flood Depth Computes water depth above terrain from a HAND raster and water level Standard (HAND-based) ✅️ ✅️ ✅️ ✅️
Inundation Produces a binary flood/no-flood mask from a HAND raster and water level Standard (HAND-based) ✅️ ✅️ ✅️ ✅️
Curve Number Runoff Estimates runoff depth from rainfall using the SCS/NRCS curve number method SCS/NRCS ✅️ ✅️ ✅️ ✅️
Travel Time Estimates overland flow travel time via simplified Manning's equation Manning 1891 ✅️ ✅️ ✅️ ✅️
Vegetation Roughness Derives Manning's roughness coefficients from NLCD land cover or NDVI SCS/NRCS ✅️ ✅️ ✅️ ✅️
Vegetation Curve Number Derives SCS curve numbers from land cover and hydrologic soil group SCS/NRCS ✅️ ✅️ ✅️ ✅️
Flood Depth (Vegetation) Manning-based steady-state flow depth incorporating vegetation roughness Manning 1891 ✅️ ✅️ ✅️ ✅️

Multispectral

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Atmospherically Resistant Vegetation Index (ARVI) Vegetation index resistant to atmospheric effects using blue band correction Kaufman & Tanre 1992 ✅️ ✅️ ✅️ ✅️
Burn Area Index (BAI) Spectral distance to charcoal reflectance point for burn scar detection Chuvieco et al. 2002 ✅️ ✅️ ✅️ ✅️
Enhanced Built-Up and Bareness Index (EBBI) Highlights built-up areas and barren land from thermal and SWIR bands As-syakur et al. 2012 ✅️ ✅️ ✅️ ✅️
Enhanced Vegetation Index (EVI) Enhanced vegetation index reducing soil and atmospheric noise Huete et al. 2002 ✅️ ✅️ ✅️ ✅️
Green Chlorophyll Index (GCI) Estimates leaf chlorophyll content from green and NIR reflectance Gitelson et al. 2003 ✅️ ✅️ ✅️ ✅️
Modified Soil Adjusted Vegetation Index (MSAVI2) Self-adjusting soil line vegetation index, no L parameter needed Qi et al. 1994 ✅️ ✅️ ✅️ ✅️
Normalized Burn Ratio (NBR) Measures burn severity using NIR and SWIR band difference USGS Landsat ✅️ ✅️ ✅️ ✅️
Normalized Burn Ratio 2 (NBR2) Refines burn severity mapping using two SWIR bands USGS Landsat ✅️ ✅️ ✅️ ✅️
Normalized Difference Built-up Index (NDBI) Picks out built-up and urban areas from SWIR and NIR bands Zha et al. 2003 ✅️ ✅️ ✅️ ✅️
Normalized Difference Moisture Index (NDMI) Detects vegetation moisture stress from NIR and SWIR reflectance USGS Landsat ✅️ ✅️ ✅️ ✅️
Normalized Difference Snow Index (NDSI) Separates snow and ice from clouds using green and SWIR bands Hall et al. 1995 ✅️ ✅️ ✅️ ✅️
Normalized Difference Water Index (NDWI) Maps open water bodies using green and NIR band difference McFeeters 1996 ✅️ ✅️ ✅️ ✅️
Modified Normalized Difference Water Index (MNDWI) Detects water in urban areas using green and SWIR bands Xu 2006 ✅️ ✅️ ✅️ ✅️
Normalized Difference Vegetation Index (NDVI) Quantifies vegetation density from red and NIR band difference Rouse et al. 1973 ✅️ ✅️ ✅️ ✅️
Optimized Soil Adjusted Vegetation Index (OSAVI) SAVI with fixed L=0.16, tuned for sparse vegetation Rondeaux et al. 1996 ✅️ ✅️ ✅️ ✅️
Soil Adjusted Vegetation Index (SAVI) Vegetation index with soil brightness correction factor Huete 1988 ✅️ ✅️ ✅️ ✅️
Structure Insensitive Pigment Index (SIPI) Estimates carotenoid-to-chlorophyll ratio for plant stress detection Penuelas et al. 1995 ✅️ ✅️ ✅️ ✅️
True Color Composites red, green, and blue bands into a natural color image Standard ✅️ ✅️ ✅️ ✅️

Classification

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Box Plot Classifies values into bins based on box plot quartile boundaries PySAL mapclassify ✅️ 🔄
Equal Interval Divides the value range into equal-width bins PySAL mapclassify ✅️
Head/Tail Breaks Classifies heavy-tailed distributions using recursive mean splitting PySAL mapclassify ✅️ 🔄 🔄
Maximum Breaks Finds natural groupings by maximizing differences between sorted values PySAL mapclassify ✅️ 🔄 🔄
Natural Breaks Optimizes class boundaries to minimize within-class variance (Jenks) Jenks 1967, PySAL ✅️ 🔄 🔄
Percentiles Assigns classes based on user-defined percentile breakpoints PySAL mapclassify ✅️ 🔄
Quantile Distributes values into classes with equal observation counts PySAL mapclassify ✅️ 🔄
Reclassify Remaps pixel values to new classes using a user-defined lookup PySAL mapclassify ✅️
Std Mean Classifies values by standard deviation intervals from the mean PySAL mapclassify ✅️

Focal

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Apply Applies a custom function over a sliding neighborhood window Standard ✅️ ✅️ ✅️ ✅️
Hotspots Identifies statistically significant spatial clusters using Getis-Ord Gi* Getis & Ord 1992 ✅️ ✅️ ✅️ ✅️
Emerging Hotspots Classifies time-series hot/cold spot trends using Gi* and Mann-Kendall Getis & Ord 1992, Mann 1945 ✅️ ✅️ ✅️ ✅️
Mean Computes the mean value within a sliding neighborhood window Standard ✅️ ✅️ ✅️ ✅️
Focal Statistics Computes summary statistics over a sliding neighborhood window Standard ✅️ ✅️ ✅️ ✅️
Bilateral Feature-preserving smoothing via bilateral filtering Tomasi & Manduchi 1998 ✅️ ✅️ ✅️ ✅️
GLCM Texture Computes Haralick GLCM texture features over a sliding window Haralick et al. 1973 ✅️ ✅️ 🔄 🔄
Sobel X Horizontal gradient via Sobel operator (detects vertical edges) Sobel & Feldman 1968 ✅️ ✅️ ✅️ ✅️
Sobel Y Vertical gradient via Sobel operator (detects horizontal edges) Sobel & Feldman 1968 ✅️ ✅️ ✅️ ✅️
Laplacian Omnidirectional second-derivative edge detector Standard ✅️ ✅️ ✅️ ✅️
Prewitt X Horizontal gradient via Prewitt operator (detects vertical edges) Prewitt 1970 ✅️ ✅️ ✅️ ✅️
Prewitt Y Vertical gradient via Prewitt operator (detects horizontal edges) Prewitt 1970 ✅️ ✅️ ✅️ ✅️

Proximity

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Allocation Assigns each cell to the identity of the nearest source feature Standard (Dijkstra) ✅️ ✅️ ✅️
Balanced Allocation Partitions a cost surface into territories of roughly equal cost-weighted area Custom ✅️ ✅️ ✅️
Cost Distance Computes minimum accumulated cost to the nearest source through a friction surface Standard (Dijkstra) ✅️ ✅️ ✅️
Least-Cost Corridor Identifies zones of low cumulative cost between two source locations Standard (Dijkstra) ✅️ ✅️ ✅️
Direction Computes the direction from each cell to the nearest source feature Standard ✅️ ✅️ ✅️
Proximity Computes the distance from each cell to the nearest source feature Standard ✅️ ✅️ ✅️
Surface Distance Computes distance along the 3D terrain surface to the nearest source Standard (Dijkstra) ✅️ ✅️ ✅️
Surface Allocation Assigns each cell to the nearest source by terrain surface distance Standard (Dijkstra) ✅️ ✅️ ✅️
Surface Direction Computes compass direction to the nearest source by terrain surface distance Standard (Dijkstra) ✅️ ✅️ ✅️

Zonal

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Apply Applies a custom function to each zone in a classified raster Standard ✅️ ✅️ ✅️ ✅️
Crop Extracts the bounding rectangle of a specific zone Standard ✅️ ✅️ ✅️ ✅️
Regions Identifies connected regions of non-zero cells Standard (CCL) ✅️ ✅️ ✅️ ✅️
Trim Removes nodata border rows and columns from a raster Standard ✅️ ✅️ ✅️ ✅️
Zonal Statistics Computes summary statistics for a value raster within each zone Standard ✅️ ✅️ ✅️ 🔄
Zonal Cross Tabulate Cross-tabulates agreement between two categorical rasters Standard ✅️ ✅️ 🔄 🔄

Interpolation

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
IDW Inverse Distance Weighting from scattered points to a raster grid Standard (IDW) ✅️ ✅️ ✅️ ✅️
Kriging Ordinary Kriging with automatic variogram fitting (spherical, exponential, gaussian) Standard (ordinary kriging) ✅️ ✅️ ✅️ ✅️
Spline Thin Plate Spline interpolation with optional smoothing Standard (TPS) ✅️ ✅️ ✅️ ✅️

Morphological

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Erode Morphological erosion (local minimum over structuring element) Standard (morphology) ✅️ ✅️ ✅️ ✅️
Dilate Morphological dilation (local maximum over structuring element) Standard (morphology) ✅️ ✅️ ✅️ ✅️
Opening Erosion then dilation (removes small bright features) Standard (morphology) ✅️ ✅️ ✅️ ✅️
Closing Dilation then erosion (fills small dark gaps) Standard (morphology) ✅️ ✅️ ✅️ ✅️
Gradient Dilation minus erosion (edge detection) Standard (morphology) ✅️ ✅️ ✅️ ✅️
White Top-hat Original minus opening (isolate bright features) Standard (morphology) ✅️ ✅️ ✅️ ✅️
Black Top-hat Closing minus original (isolate dark features) Standard (morphology) ✅️ ✅️ ✅️ ✅️

Fire

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
dNBR Differenced Normalized Burn Ratio (pre minus post NBR) USGS ✅️ ✅️ ✅️ ✅️
RdNBR Relative dNBR normalized by pre-fire vegetation density USGS ✅️ ✅️ ✅️ ✅️
Burn Severity Class USGS 7-class burn severity from dNBR thresholds USGS ✅️ ✅️ ✅️ ✅️
Fireline Intensity Byram's fireline intensity from fuel load and spread rate (kW/m) Byram 1959 ✅️ ✅️ ✅️ ✅️
Flame Length Flame length derived from fireline intensity (m) Byram 1959 ✅️ ✅️ ✅️ ✅️
Rate of Spread Simplified Rothermel spread rate with Anderson 13 fuel models (m/min) Rothermel 1972, Anderson 1982 ✅️ ✅️ ✅️ ✅️
KBDI Keetch-Byram Drought Index single time-step update (0-800 mm) Keetch & Byram 1968 ✅️ ✅️ ✅️ ✅️

Raster / Vector Conversion

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Polygonize Converts contiguous regions of equal value into vector polygons Standard (CCL) ✅️ ✅️ ✅️ 🔄
Contours Extracts elevation contour lines (isolines) from a raster surface Standard (marching squares) ✅️ ✅️ 🔄 🔄
Rasterize Rasterizes vector geometries (polygons, lines, points) from a GeoDataFrame Standard (scanline, Bresenham) ✅️ ✅️

Multivariate

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Mahalanobis Distance Measures statistical distance from a multi-band reference distribution, accounting for band correlations Mahalanobis 1936 ✅️ ✅️ ✅️ ✅️

Pathfinding

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
A* Pathfinding Finds the least-cost path between two cells on a cost surface Hart et al. 1968 ✅️ 🔄 🔄
Multi-Stop Search Routes through N waypoints in sequence, with optional TSP reordering Custom ✅️ 🔄 🔄

Diffusion

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Diffuse Runs explicit forward-Euler diffusion on a 2D scalar field Standard (heat equation) ✅️ ✅️ ✅️ ✅️

Dasymetric

Name Description Source NumPy xr.DataArray Dask xr.DataArray CuPy GPU xr.DataArray Dask GPU xr.DataArray
Disaggregate Redistributes zonal totals to pixels using an ancillary weight surface Mennis 2003 ✅️ ✅️ ✅️ ✅️
Pycnophylactic Tobler's pycnophylactic interpolation preserving zone totals via Laplacian smoothing Tobler 1979 ✅️

Usage

Quick Start

Importing xrspatial registers an .xrs accessor on DataArrays and Datasets, giving you tab-completable access to every spatial operation:

import xrspatial
from xrspatial.geotiff import read_geotiff

# Read a GeoTIFF (no GDAL required)
elevation = read_geotiff('dem.tif')

# Surface analysis — call operations directly on the DataArray
slope = elevation.xrs.slope()
hillshaded = elevation.xrs.hillshade(azimuth=315, angle_altitude=45)
aspect = elevation.xrs.aspect()

# Classification
classes = elevation.xrs.equal_interval(k=5)
breaks = elevation.xrs.natural_breaks(k=10)

# Proximity
distance = elevation.xrs.proximity(target_values=[1])

# Multispectral — call on the NIR band, pass other bands as arguments
nir = xr.DataArray(np.random.rand(100, 100), dims=['y', 'x'])
red = xr.DataArray(np.random.rand(100, 100), dims=['y', 'x'])
blue = xr.DataArray(np.random.rand(100, 100), dims=['y', 'x'])

vegetation = nir.xrs.ndvi(red)
enhanced_vi = nir.xrs.evi(red, blue)
Dataset Support

The .xrs accessor works on Datasets too. Single-input functions apply the operation to each data variable. Multi-input functions (multispectral indices) accept string kwargs that map band aliases to variable names:

ds = xr.Dataset({'band_4': red, 'band_5': nir})

# Single-input: slope computed for each variable
slope_ds = ds.xrs.slope()

# Multi-input: map variable names to band parameters
ndvi_result = ds.xrs.ndvi(nir='band_5', red='band_4')
Function Import Style

All operations are also available as standalone functions if you prefer explicit imports:

from xrspatial import hillshade, slope, ndvi

hillshaded = hillshade(elevation)
slope_result = slope(elevation)
vegetation = ndvi(nir, red)

Check out the user guide here.


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Dependencies

Core: numpy, numba, scipy, xarray, matplotlib, zstandard

Optional:

  • pyproj — WKT/PROJ CRS resolution
  • cupy — GPU acceleration
  • dask — out-of-core processing
  • libnvcomp — GPU batch decompression (deflate, ZSTD)
  • kvikio — GPUDirect Storage (SSD → GPU)
  • fsspec + s3fs/gcsfs/adlfs — cloud storage

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Notes on GDAL

xarray-spatial does not depend on GDAL. The built-in GeoTIFF/COG reader and writer (xrspatial.geotiff) handles raster I/O natively using only numpy, numba, and the standard library. This means:

  • Zero GDAL installation hassle. pip install xarray-spatial gets you everything needed to read and write GeoTIFFs, COGs, and VRT files.
  • Pure Python, fully extensible. All codec, header parsing, and metadata code is readable Python/Numba, not wrapped C/C++.
  • GPU-accelerated reads. With optional nvCOMP, compressed tiles decompress directly on the GPU via CUDA -- something GDAL cannot do.

The native reader is pixel-exact against rasterio/GDAL across Landsat 8, Copernicus DEM, USGS 1-arc-second, and USGS 1-meter DEMs. For uncompressed files it reads 5-7x faster than rioxarray; for compressed COGs it is comparable or faster with GPU acceleration.

Citation

Cite this code:

xarray-contrib/xarray-spatial, https://github.com/xarray-contrib/xarray-spatial, ©2020-2026.