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Bathymetric Survey — The First Step of Every Assessment

Before a single equation is run, we survey the shape of the basin. The bathymetry — depth, area and volume as a function of depth — is the foundation on which every stratification index, oxygen budget, plume model and diffuser placement is built. No bathymetry, no defensible assessment.

Bathymetry Is the Design Basis, Not a Detail

Almost every number in an aeration or restoration assessment is derived from the basin shape

It Sets Depth & Volume

Mean depth, maximum depth and working volume come straight from the survey. These set the residence time, the stratification potential and the oxygen mass the water column can hold — the first inputs every model needs.

It Defines the Hypsographic Curve

The depth–area–volume (hypsographic) curve — how much area and volume sit at each depth — is what the stability indices integrate over and what fixes the sediment area driving oxygen demand.

It Drives Diffuser Placement

Per-position bed depth from the survey sets the local oxygen-transfer efficiency, the plume rise height and the bed clearance at every candidate diffuser — so the layout is engineered to the real basin, not an idealised box.

From Soundings to a Digital Basin

Survey-grade depth and position, processed into the curves the models consume

Echo-Sounding & Positioning

Single-beam or multibeam echo-sounders log depth along survey transects while RTK-GNSS fixes horizontal position to centimetre accuracy, referenced to a datum — producing a dense, georeferenced point cloud of the bed.

USV & Drone Platforms

Uncrewed survey vessels and drones extend coverage into shallow margins and confined or inaccessible water bodies safely and repeatably, capturing the shoreline and the bed without launching a manned boat.

Surface Model & Curves

The point cloud is gridded into a digital terrain model of the bed, the shoreline polygon is integrated for surface area, and the depth–area–volume curves and contour map are derived — the deliverables the engineering models read directly.

What the Survey Produces — and Why the Models Need It

Surface area is the integral of the shoreline polygon (the shoelace formula on the survey vertices). Volume is the depth integral of the area function, V = ∫ A(z) dz over the hypsographic curve, and the volume-weighted mean depth is simply V / A₀. These are not cosmetic figures: the Schmidt stability and the Lake number are moments computed over A(z); the sediment oxygen demand scales with the bed area at each depth; the days-to-anoxia resilience is V·DO divided by the demand; and the bubble-plume rise height and detrainment depend on the local depth at the diffuser. Get the bathymetry wrong and every one of those derived quantities is wrong with it — which is exactly why the survey is the first thing we do, not the last.

What the Survey Gives the Assessment

Each output is a direct input to a documented model downstream

Depth Contour Map

A contoured bathymetric chart of the basin to a defined datum, the base layer for diffuser layout and CFD geometry.

Hypsographic Curve

Area and volume as a function of depth — the curve the stability indices and oxygen-demand terms integrate over.

Morphometry

Surface area, mean and maximum depth, working volume and shoreline development — the headline geometry of the water body.

Per-Position Bed Depth

Local depth at every candidate diffuser position, setting oxygen-transfer efficiency, plume height and bed clearance.

Sediment-Area Map

The bed area at each depth band that drives sediment oxygen demand and internal nutrient flux.

Survey-Ready Mesh

A clean digital terrain model that becomes the geometry for plume and circulation CFD verification.

Need a bathymetric survey to start an assessment?

Reynolds & Bauhm captures survey-grade bathymetry and turns it into the depth–area–volume curves, morphometry and per-position bed depths that every stratification, oxygen-budget and plume model depends on.

Industries We Serve

Our expertise spans multiple industries with sector-specific water treatment solutions.