Arc Hydro Tools -

This is the foundational step for most hydrological modeling. It transforms raw Digital Elevation Models (DEMs) into hydrologically corrected surfaces.

| Step | Tool/Process | Output | |------|--------------|--------| | 1. DEM Manipulation | Fill Sinks | Depressionless DEM | | 2. Flow Direction | D8 Algorithm | Flow direction grid | | 3. Flow Accumulation | Accumulate Streams | Accumulated flow (cell count/area) | | 4. Stream Definition | Stream Definition (threshold) | Binary stream grid | | 5. Stream Segmentation | Stream Link | Stream segments | | 6. Catchment Delineation | Catchment Grid Delineation | Drainage area for each segment | | 7. Drainage Line Processing | Drainage Line, Adjoint Catchment | Vectorized river network & nested catchments | | 8. Network Construction | Hydro Network, Longest Flow Path | Connected geometric network & basin length | arc hydro tools

Arc Hydro acts as a bridge between geographic information systems (GIS) and specialized hydrologic simulation models. Its primary functions include: Pre-modeling by Arc Hydro Tools This is the foundational step for most hydrological modeling

Arc Hydro includes a predefined schema (the Arc Hydro Data Model) that links spatial features with temporal data. DEM Manipulation | Fill Sinks | Depressionless DEM | | 2