Catchment Area Module¶

File: computing/misc/catchment_area.py

Overview¶

This module generates catchment area raster layers by clipping pan-India catchment data to specific regions of interest. It supports both standard administrative boundaries (state/district/block) and custom project-based ROIs.

Purpose¶

Processes catchment area data for: - MWS (Micro-Watershed) applications with administrative boundaries - Custom Projects with user-defined ROI paths - Distributes to GEE, GeoServer (via GCS), and database

Architecture¶

flowchart TD
    A[Celery Task Triggered] --> B{Has state/district/block?}
    B -->|Yes| C[Build Standard ROI]
    B -->|No| D[Use Custom ROI Path]
    C --> E[Load MWS FeatureCollection]
    D --> F[Load Custom FeatureCollection]
    E --> G[Load Pan-India Catchment Raster]
    F --> G
    G --> H[Clip to ROI]
    H --> I[Call Raster Generation Function]
    I --> J{Asset Exists?}
    J -->|No| K[Export Raster to GEE]
    K --> L[Check Task Status]
    L --> M[Sync to GCS]
    M --> N[Sync GCS to GeoServer]
    N --> O{Success?}
    O -->|Yes| P[Update Sync Status]
    P --> Q[Return True]
    J -->|Yes| R[Skip Export]
    R --> M

Components¶

Main Task: generate_catchment_area_singleflow()¶

Location: Line 25

Parameters: | Parameter | Type | Description | |-----------|------|-------------| | state | str, optional | State name | | district | str, optional | District name | | block | str, optional | Block/tehsil name | | gee_account_id | int, optional | GEE account identifier | | proj_id | int, optional | Project ID for custom projects | | roi_path | str, optional | Custom ROI asset path | | asset_suffix | str, optional | Custom asset suffix | | asset_folder | list, optional | Custom asset folder path | | app_type | str | Application type (default: "MWS") |

Returns: bool - Whether layer was successfully synced to GeoServer

Helper Function: catchment_area_raster_generation()¶

Location: Line 85

Handles the actual raster export and synchronization logic.

Parameters: | Parameter | Type | Description | |-----------|------|-------------| | raster | ee.Image | Clipped raster image | | roi | ee.FeatureCollection | Region of interest | | proj_id | int, optional | Project ID | | state | str, optional | State name | | district | str, optional | District name | | block | str, optional | Block name | | description | str | Layer description | | asset_id | str | GEE asset identifier |

Processing Logic¶

1. ROI Determination¶

flowchart LR
    A{Standard Mode?} -->|Yes| B[Build MWS ROI Path]
    A -->|No| C[Use Custom ROI]
    B --> D[get_gee_asset_path]
    C --> E[get_gee_dir_path]
    D --> F[Load FeatureCollection]
    E --> F

2. Data Source¶

catchment_area_raster = ee.Image(CATCHMETN_AREA)  # From constants.pan_india_urls

3. Raster Processing¶

raster = catchment_area_raster.clip(roi_boundary.geometry())

Integration Points¶

computing/misc/catchment_area.py
├── computing.utils
│   ├── save_layer_info_to_db()   # Database persistence
│   └── update_layer_sync_status() # Status tracking
├── utilities.gee_utils
│   ├── ee_initialize()           # GEE authentication
│   ├── check_task_status()       # Task monitoring
│   ├── valid_gee_text()          # Text sanitization
│   ├── get_gee_asset_path()      # Asset path generation
│   ├── is_gee_asset_exists()     # Asset existence check
│   ├── sync_raster_to_gcs()      # GCS synchronization
│   ├── sync_raster_gcs_to_geoserver() # GeoServer sync
│   ├── export_raster_asset_to_gee() # Raster export
│   ├── make_asset_public()       # ACL management
│   └── get_gee_dir_path()        # Directory path generation
├── utilities.constants
│   └── GEE_PATHS                 # GEE path configurations
├── constants.pan_india_urls
│   └── CATCHMETN_AREA            # Pan-India catchment URL
└── projects.models
    └── Project                    # Project model for custom projects

Output¶

Dataset Name: Catchment Area

Raster Sync Workflow¶

flowchart LR
    A[GEE Asset] --> B[sync_raster_to_gcs]
    B --> C[Google Cloud Storage]
    C --> D[sync_raster_gcs_to_geoserver]
    D --> E[GeoServer]

This module uses the Raster Sync Pattern: 1. Export raster to GEE asset 2. Sync GEE asset to Google Cloud Storage (GCS) 3. Sync GCS to GeoServer for WMS/WCS publication

Usage¶

Standard Administrative Boundary¶

from computing.misc.catchment_area import generate_catchment_area_singleflow

result = generate_catchment_area_singleflow.delay(
    state="Rajasthan",
    district="Jaipur",
    block="Sanganer",
    gee_account_id=1
)

Custom Project¶

result = generate_catchment_area_singleflow.delay(
    proj_id=123,
    roi_path="projects/earthengine-legacy/assets/projects/custom/roi",
    asset_suffix="project_123",
    asset_folder=["CustomProject"],
    app_type="WATERBODY",
    gee_account_id=1
)

Dependencies¶

• ee (Google Earth Engine Python API)
• Celery - Distributed task queue
• projects.models.Project - For custom project support