Flood Return Periods: Understanding 50-, 100- and 500-Year Events
Understand return periods, annual exceedance probability and flood risk over a project's lifetime.
Knowledge Base
Expert insights on flood risk analysis, hydrological reporting, and river rehabilitation projects.
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Reading Flood Hazard Maps: Depth, Velocity and Extent
Interpret flood extent, depth and velocity together, checking scenarios, elevation references and model limits.
Parcel Flood Risk: Ground and Building Elevations
Learn how parcel, building, road and entry elevations are compared with floods and why fill options need joint modelling.
Data and Project Files Required for Flood Analysis
A practical guide to preparing location, survey, rainfall-flow, structure and authority-request files for a flood study.
Uncertainty and Scenario Analysis in Flood Models
Use scenarios to examine uncertainty in discharge, terrain, roughness and boundary conditions.
Rainfall Intensity, Duration and Frequency: IDF Curves
Distinguish rainfall depth from intensity and check duration, frequency, units and data limits in IDF curves.
Determining a Catchment's Time of Concentration
Assess concentration time using flow paths, surfaces and method limits, distinguishing it from storm duration and model lag.
The Rational Method: Flow Calculation, Units and Limits
Apply Q = 0.278 C i A with consistent units and understand peak discharge, runoff coefficients, critical duration and limitations.
The SCS-CN Method: From Rainfall to Direct Runoff
Explore curve number, retention and initial abstraction, distinguishing runoff depth, volume and peak discharge.
Delineating Catchments from Digital Terrain Models
Delineate from outlets, flow direction and accumulation while checking depressions, culverts and urban drainage.
Terrain for HEC-RAS: Resolution, Elevations and Survey Quality
Prepare hydraulic terrain by checking resolution, vertical accuracy, channel bed and structure representation together.
HEC-RAS Boundary Conditions: Hydrographs, Stage and Normal Depth
Choose flow, stage and normal-depth boundaries carefully, checking timing and elevation references.
Manning Roughness and Sensitivity Analysis
Justify Manning n using surfaces, vegetation, geometry and flow, with Cowan estimates and sensitivity checks.
HEC-RAS 2D: Cell Size, Breaklines and Time Steps
Build meshes around hydraulic controls and assess cell size, breaklines, time steps, stability and sensitivity together.
Hydraulic Model Calibration and Validation
Use observed levels, flows and flood marks, distinguishing calibration, independent validation and numerical checks.
Normal and Critical Depth in Open Channels
Distinguish normal depth, critical depth and actual profiles using Manning, Froude number and an example section.
River Channel Sections: Rectangular and Trapezoidal Options
Compare rectangular and trapezoidal sections through area, perimeter, velocity, freeboard, site constraints and maintenance.
Evaluating Freeboard in Hydraulic Design
Assess allowances above water levels considering uncertainty, waves, blockage and maintenance.
Bank Protection: Riprap, Gabions and Vegetation
Choose protection using shear, scour, filters, transitions and maintenance, not material names alone.
Sediment Transport and Bed Stability in River Rehabilitation
Examine sediment supply, transport capacity, deposition and scour, with data, scenario and maintenance requirements.
Climate Change and Flood Discharges
Basin- and scenario-specific climate sensitivity assessment of flood discharges.
Hydraulic Sizing of Bridges and Culverts
Discharge, water level, freeboard and scour assessments for bridges and culverts.
What Is 2D Flood Analysis? Comparing HEC-RAS 1D and 2D
HEC-RAS 2D flood analysis: terrain data, mesh, boundary conditions, maps and result checks.
DSİ Flood Reports and the Building-Permit Process
Understand flood reports, authority opinions and building permits in Turkey: report scope, required data, method selection and steps after delivery.
Preparing a Hydrological Study Report
Hydrological study steps based on rainfall data, catchment properties and project requirements.