---
title: "D0 and D100 Option | Sediment Transport"
slug: "d0-and-d100-option"
description: "Learn about the D0 and D100 options for your datafile."
tags: ["1D river modelling"]
updated: 2022-11-01T15:42:20Z
published: 2022-11-01T15:42:20Z
canonical: "help.floodmodeller.com/d0-and-d100-option"
stale: true
---

> ## Documentation Index
> Fetch the complete documentation index at: https://help.floodmodeller.com/llms.txt
> Use this file to discover all available pages before exploring further.

# D0 and D100 Option

Dand D, the extreme sizes in the sediment distribution, are used when bed material sizes are listed in the model output. When a size is near an extreme in the range, such as the Dbed material size, then it often cannot be interpolated between two of the input sediment sizes. In such cases the extreme size, Dor D, is needed. The program takes by default Das half the finest size input and Das twice the largest size input. Use of this option enables the Dand Dsizes to be specified more precisely. Its use is recommended when the SORTED algorithm is selected because the Dsize will usually be needed in determining the active layer thickness, which is a factor of the Dsize in the bed material. An example of the structure of this section of the file is shown in Figure 5.

## Datafile Format –Bed material data block

Line 1 keyword 'D0D100'

Line 2 D0 D100

Where

D0, D100 = the extreme sizes in the sediment distribution, mm