Detailed Water Volume Analysis in BioBase

BioBase software automates things, and water volume analysis was next on our list. Accurate water volume estimation is a foundational requirement for lake, pond, reservoir, and stormwater management, hydropower operations, sedimentation studies, and regulatory reporting. Until now, it was a complicated job of manual calculations left to civil engineers. As a result, despite its importance, everyday practitioners have been relegated to either using curves drawn on yellowing paper from the 1970’s or just “ballparking” water volume from some spot measurements and crude math. Not anymore!

BioBase now automates this process by generating hypsographic (otherwise known as hypsometric) water volume analyses for every upload and merged survey. These analyses quantify water volume as a function of depth, producing both visual and tabular outputs that are immediately usable for technical analysis.

Accessing Hypsographic Analysis in BioBase

Once a bathymetric surface is generated, hypsographic analysis is automatically available within the BioBase map (Figure 1).

Exporting Hypsographic Charts and Data

Figure 2 shows the export interface, including the option to generate hypsographic charts and CSV summary data.

From this menu, users can export:

• • A hypsographic chart visualizing depth, area, and volume relationships

  • A CSV file containing detailed depth-resolved area and volume statistics. Statistics are generated at one foot or one meter increments depending on your measurement preferences

These exports are generated directly from the mapped bathymetric surface.

What Is a Hypsographic (Hypsometric) Analysis and How Can It Help Me Manage Lakes?

Rather than reporting a single total volume, this approach answers questions such as:

• • How much water is stored above or below a given depth?

  • How does volume change as water levels rise or fall?

  • Where is storage concentrated within the basin?

  • How much well-oxygenated habitat volume do I have for the fish I am managing?

• • How much herbicide do I need to apply in order to achieve the concentration required to target and kill the invasive species in the lake?

This feature also helps practitioners with drawdown planning, sedimentation assessment, flood storage, stormwater capacity, and aeration sizing

Trapezoidal Volume Integration

BioBase estimates water volume using the trapezoidal method, a widely accepted numerical integration approach used in bathymetry, hydrology, and reservoir analysis.

The method operates by:

• • Dividing the bathymetric surface into discrete depth intervals (typically one-foot or one-meter increments)

  • Calculating horizontal surface area at successive depth levels

  • Estimating the volume between adjacent depth intervals by averaging their areas

  • Accumulating incremental volumes from the surface downward

Each depth interval represents a three-dimensional “slice” of the basin. Summing these slices produces cumulative water volume as a function of depth.

This approach is well suited for irregular basin geometries and discrete survey data and provides stable, repeatable results when applied at sufficiently fine depth resolution.

Interpreting the Hypsographic Outputs

Hypsographic Chart

BioBase generates a hypsographic chart that visualizes the relationship between depth, area, and cumulative volume (Figure 3). This chart allows users to quickly assess where volume is concentrated within the basin.

Example: Quantifying Fish Habitat Volume of An Endangered Cold Water fish

Cisco (Coregonus artedi) is an endangered cold water fish in Indiana. These species require cold, well-oxygenated water. This habitat is disappearing across the range of cisco due to effects of nutrient pollution and climate change. In a previous blog, we showcased how our fish layer, EcoFish™ could help fisheries investigators locate and monitor some of the few remaining populations of cisco in the state. The hypsographic feature coupled with a Temp-Dissolved Oxygen profile provides additional powerful information about the precise habitat volume available to cisco during the most stressful time of year. Specifically, calculating total fish habitat volume available for this snapshot in time. With continued Temp-DO monitoring, the actual 3-dimensional habitat volume can also be monitored and tracked over time.

Limitations and Considerations

While BioBase’s hypsographic volume analysis provides a robust and repeatable method for estimating water volume, users should consider the following limitations.

Survey Coverage

Hypsographic calculations assume that the entire waterbody or area of interest is fully covered by survey data. Areas that are not surveyed are not represented in the bathymetric surface and therefore do not contribute to calculated area or volume.

Incomplete coverage may result in:

• • Underestimated total volume

  • Distorted hypsographic curves

  • Incomplete cumulative summaries

For best results, surveys should include complete shoreline-to-shoreline coverage and capture the full depth range of the basin.

Vegetation and Bottom Obstruction

Water volume estimates depend on accurate detection of the true bottom surface. In areas with extremely dense aquatic vegetation, depth measurements may reflect the vegetation canopy rather than the underlying bottom.

In these conditions:

• • Depth values may be biased shallow

  • Areas at deeper intervals may be underrepresented

  • Volume estimates may be underestimated

Users should apply caution when interpreting results in heavily vegetated systems and consider survey timing or supplemental methods where vegetation obscures bottom detection. For example, conducting bathymetric surveys in early spring before peak vegetation growth. Or carefully reviewing the bottom tracking in dense vegetation and correcting depths accordingly.

Fit-for-Purpose Water Volume Mapping

BioBase is purpose-built for waterbody mapping and analysis, making it particularly well suited for water volume assessments.

Independent evaluations have demonstrated that alternative sonar-based mapping platforms can deliver accurate results at significantly lower cost than traditional, commercial survey approaches. BioBase builds on this foundation by adding hypsographic analysis to its suite of automated variables.

Conclusion

Hypsographic analysis transforms bathymetric maps from visual products into quantitative tools. By automatically generating depth-resolved area and volume summaries for every mapped waterbody, BioBase provides users with immediate insight into how much water is stored throughout a basin. Anyone can now do this with their off-the-shelf depthfinder. Consumer technology like Lowrance and BioBase has now automated this part of the equation of lake and reservoir management. Lake and reservoir management is difficult enough with enumerable unknowns. Not knowing anything about depth and water volume will only compound problems. Let BioBase take care of the mapping and you, as a manager can focus on management and conservation.