OpenDSAS (Digital Shoreline Analysis System)

OpenDSAS is a high-performance, cross-platform reimplementation of the USGS
Digital Shoreline Analysis System (DSAS).
It is designed for fast, memory-efficient shoreline change analysis in command-line workflows.

Compared to the official USGS DSAS:

• 🚀 Up to 100× faster execution
• 💾 Uses only ~5% of the memory
• 🖥️ Optimized for Linux + CLI/HPC environments

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🔍 Why OpenDSAS?

OpenDSAS is ideal if:

• Your shoreline analysis is large-scale, time-consuming, or memory-intensive
• You prefer command-line workflows and Linux HPC environments
• You need parallelized computation on large datasets

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📦 Installation

pip (Linux, macOS arm64, Windows)

pip install opendsas

This installs the same static dsas binary published in Releases, wrapped in a platform wheel — no compiler or build step required.

Linux

Download the pre-built static binary — this URL always points to the latest release:

curl -LO https://github.com/lubyant/OpenDSAS/releases/latest/download/opendsas-linux-x86_64
chmod +x opendsas-linux-x86_64
sudo mv opendsas-linux-x86_64 /usr/local/bin/dsas

For ARM (servers, Raspberry Pi), use opendsas-linux-arm64 instead of opendsas-linux-x86_64.

The binary is fully statically linked — it runs on any Linux distribution (Ubuntu, Debian, RHEL, Alpine, etc.) with no dependencies.

macOS

Install via Homebrew using the OpenDSAS tap:

brew tap lubyant/opendsas https://github.com/lubyant/OpenDSAS
brew install lubyant/opendsas/opendsas

Requires Apple Silicon (M1/M2/M3). An Intel build is not provided.

Windows

Download opendsas-vX.Y-windows-x86_64.exe from Releases, rename it to dsas.exe, and add it to your PATH.

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Build from Source

Prerequisites

• CMake ≥ 3.14
• C++20-compatible compiler (GCC 11+, Clang 14+, MSVC 2022+)
• macOS only: brew install libomp

All other dependencies (nlohmann/json, shapelib, argparse) are fetched automatically by CMake.

git clone https://github.com/lubyant/OpenDSAS.git
cd OpenDSAS

cmake -B build -S . -DCMAKE_BUILD_TYPE=Release
cmake --build build -j$(nproc)

# optional: install to system PATH
sudo cmake --install build

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⚙️ Usage

Supported Input Formats

Both Shapefile (.shp) and GeoJSON (.geojson / .json) are accepted for all input files.
All input and output files in a single command must use the same format — mixing formats (e.g. a .geojson input with a .shp output) is an error.

Quick Example

# Shapefile inputs
dsas --baseline baseline.shp --shoreline shoreline.shp --transect-length 1000 --transect-spacing 10

# GeoJSON inputs
dsas --baseline baseline.geojson --shoreline shoreline.geojson \
     --output-intersect intersects.geojson --output-transect transects.geojson \
     --transect-length 1000 --transect-spacing 10

Command-Line Options

Root Command

Option	Description	Default
-h, --help	Show help message	—
-v, --version	Print version info	—
--baseline [FILE]	Path to baseline file (.shp or .geojson)	—
--bid-field [STR]	Field name for baseline ID in baseline data	id
--shoreline [FILE]	Path to shoreline file (.shp or .geojson)	—
--date-field [STR]	Field name for date in shoreline data	Date
--date-format [STR]	Date format in shoreline data	%Y/%m/%d
--output-intersect [FILE]	Output intersections file (must match input format)	intersects.shp
--output-transect [FILE]	Output transects file (must match input format)	transects.shp
--smooth-factor [N]	Smoothing factor	1
--transect-length [N]	Transect length	500
--transect-spacing [N]	Spacing between transects	30
--intersection-mode [MODE]	Intersection rule: closest or farthest	closest
--transect-orientation [MODE]	Transect orientation: left, right, or mix (half left, half right)	mix
-bi, --build_index	Build spatial index (faster queries, slower initial build)	false

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Cast Command

Generate transects from a baseline.

Click to expand cast options

Option	Description	Default
-h, --help	Show help message	—
-v, --version	Print version info	—
--baseline [FILE]	Path to baseline file (.shp or .geojson) (required)	—
--bid-field [STR]	Field name for baseline ID in baseline data	id
--output-transect [FILE]	Output transects file (must match input format)	transects.shp
--smooth-factor [N]	Smoothing factor	1
--transect-length [N]	Transect length	500
--transect-spacing [N]	Spacing between transects	30
--intersection-mode [MODE]	Intersection rule: closest or farthest	closest
--transect-orientation [MODE]	Transect orientation: left, right, or mix	mix

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Cal Command

Generate intersections and calculate erosion rates using predefined transects.

Click to expand cal options

Option	Description	Default
-h, --help	Show help message	—
-v, --version	Print version info	—
--transect [FILE]	Path to transect file (.shp or .geojson) (required)	—
--shoreline [FILE]	Path to shoreline file (.shp or .geojson) (required)	—
--date-field [STR]	Field name for date in shoreline data	Date
--date-format [STR]	Date format in shoreline data	%Y/%m/%d
--output-intersect [FILE]	Output intersections file (must match input format)	intersects.shp
--intersection-mode [MODE]	Intersection rule: closest or farthest	closest
--transect-orientation [MODE]	Transect orientation: left, right, or mix	mix
-bi, --build_index	Build spatial index (faster queries, slower initial build)	false

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🗂 Preparing Input Data

Input files may be Shapefile (.shp) or GeoJSON (.geojson / .json).
All files in one command invocation must use the same format.

Shoreline File

Must contain a Date field (or the name given by --date-field):

Date
YYYY/MM/DD

• Example: 2000/01/01
• A shoreline ID field is auto-generated (custom IDs not yet supported)

Baseline File

Must contain an Id field (or the name given by --bid-field):

Id
baseline id

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📤 Output

OpenDSAS generates two output files (Shapefile by default; format matches your inputs):

1. intersects.shp

BaselineId	TransectId	ShoreID	Date	ref_dist	X	Y
baseline id	transect id	shoreline id	intersection date	distance to baseline	x	y

2. transects.shp

TransectId	BaselineId	ChangeRate
transect id	baseline id	shoreline change rate

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🛠 Roadmap

• GUI frontend

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📚 Citing OpenDSAS

If you use OpenDSAS in your research, please cite it as:

@misc{OpenDSAS,
  author       = {Lu, Boyuan; Wang, wei},
  title        = {OpenDSAS: A High-Performance Digital Shoreline Analysis System},
  year         = {2025},
  publisher    = {GitHub},
  journal      = {GitHub repository},
  howpublished = {\url{https://github.com/lubyant/OpenDSAS}},
}

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📜 License

MIT License