Catchment Area Delineation
Definition
Catchment Area Delineation is the GIS-based process of identifying the boundaries of a drainage basin or service zone that contributes surface flow to a particular point or facility. This is a foundational step in hydrological modeling and resource management, ensuring that all upstream contributing regions are accounted for.
Application
Applied in flood modeling, stormwater management, and water quality analysis, delineation helps planners design infrastructure like dams, treatment plants, and culverts. In urban contexts, it supports efficient public service allocation and risk mapping. Tools in ArcGIS, QGIS, and HEC-HMS are commonly used for automated catchment delineation.
FAQ
1. Why is catchment delineation important in hydrology?
It ensures that all water sources influencing a point are included in models, improving accuracy in flood prediction and water balance calculations.
2. Why is catchment delineation important in hydrology?
High-resolution DEMs, stream network layers, flow direction and accumulation data are essential inputs.
3. Why is catchment delineation important in hydrology?
While often used interchangeably, 'watershed' can refer to a broader region, while 'catchment' often denotes the specific area draining to a point of interest.
4. Why is catchment delineation important in hydrology?
HEC-HMS, Arc Hydro, TauDEM, and QGIS Hydrological Analysis Toolbox are commonly used for automated workflows.