Soil

Introduction

The Soil cluster provides a series of components that define the basic characteristics of the soil (content ratio, water, organic matter), that calculate the water holding capacity based on the soil type, and that create parametric diagrams based on these information.

Soil Type

Soil types in BeingAliveLanguage are referenced from USDA soil texture classification system, which differentiates 12 soil types by the ratio of three primary particles: sand, silt and clay. The soil types are summarised in the textural triangle¹ on the left.

Beyond the three particles, water, organic matter and air play a role in soil system as well. By specifying the soil type, the possible range of water content in a soil type can be estimated using existing research data, while organic matter content should be measured from field test considering its seasonal and regional variations. The following chart on the right shows available water in various soil types.

Soil Content Representation

The soil contents are visualized in a unified triangle frame which is deliberately chosen for connection to USDA soil system and the preferable tessellation ability. The three primary particles - sand, silt, and clay - are represented with triangles of three sizes from large to small. Information about water content, including wilting point, current water stage, field capacity and saturation, is shown by triangles between the soil core triangle and outmost layer. The organic matter inside the soil, located at the outmost part of the soil, is illustrated by radial hatching.

Component Usage

Please refer to the following sections for each component from this cluster. Some of the components also generate required information for component usage in the Root and Climate cluster.

Soil Base

This component creates a triangle grid inside the given solid boundary.

Soil Analysis

This component defines the soil type and generates information of soil based on the ratio of the three soil contents.

General Soil Separates

This component generates a soil map according soil base and soil contents. If rock curves are provided, the rock area will be bypassed.

The component takes a pre-generated soil base (a triangle map) and defined soil information to generate diagrams representing the soil composition. The locations of the different-size triangles are randomly distributed.

Optional rock curves can be added to generate a soil map that avoids the unfavoured area.

General Soil Separates with Randomness Control

This component offers enhanced control over the randomness of the triangles' distribution. Given that the majority of the parameters align with those found in the General Soil Separates component, we will focus on introducing the additional stage parameter here, which is utilized to regulate the randomness.

• Randomness: Index 1 indicates a relatively even distribution with a low level of randomness, while index 8 represents highest level of randomness, shown in the following diagram.

• State Preservation: Due to certain technical issues with 'Possion's Disk Sampling with Elimination'², the state preservation with seed is currently unstable within this component. This instability implies that saving and reopening the file may result in changes of the distribution.

Example S1

Download the GH file

This example demonstrates the usage of Soil Base, Soil Analysis, and Soil Separates components to create a specific soil contents.

Soil Compaction

This component generates diagram of soil compaction based on given the given compaction area and strength.

Soil compaction refers to 'the process in which a stress applied on soil causes densification as air is displaced from the pores between the soil grains'.³ The dynamics of compaction are influenced by many factors, such as soil water content, texture, and applied stress. Moreover, the severity of compaction diminishes with increasing depth, meaning surface soil tends to be more compacted than the soil at greater depths. This component models such phenomena and use inputs such as soil triangles, compacted depth, and stress strength to generate a corresponding compaction diagram.

• Notes on Particle Collision: Since the component does not incorporate built-in collision detection, there is a possibility that particles may overlap with others. This scenario often arises when the Compact Depth parameter is set to a low value, while Strength is set high. In such instances, it is recommended to adjust these values accordingly.
  Another common collision scenario occurs at the boundary between compacted and non-compacted soil, specifically when only a portion of the soil has been compacted. To address this issue, some manual intervention may be required. For example, users could consider separating the boundaries of non-compacted part from the compacted part whening using Soil Base component and the General Soil Separates component to generate soil triangles.

Soil Water Visualization

This component generates a soil diagram with essential water information.

Taking defined soil information and desired soil triangles as inputs, the component generates five group of curves which stand for core triangles, wilting point triangles, field capacity triangles, saturation triangles and current water triangles.

Soil Water Content Hatch

The hatch of different water content could be customized using outputs from Soil Water Visualization component and Pattern Hatch component embedded in Grasshopper. It is highly recommended to graft the triangles before linking to the hatch component, as this can speed up the operation considerably. If colorful pattern is favored, one could also consider creating nurbs surfaces from the triangles and coloring the surfaces.

Example S2

Download the GH file

This example demonstrates the usage of Soil Compaction and Soil Water Visulization components to compact the soil and and visualize its water content.

Soil Organic Matter

To visualize the organic matter inside the soil, we differentiate the interior and surface organic matter:

• interior organic matter: organic matter that exists inside the soil.
• surface organic matter: organic matter that exists on the soil surface.

As in reality, organic matter from the top surface will gradually merge into the soil and increase interior organic matter near the top, users should adjust the density of the two parts so that the visualization delivers the correct information.

Soil Interior Organic Matter

This component generates the diagram of soil interior organic matter for the given soil base map.

Soil Surface Organic Matter

As the diagram of the top surface is not related to the specific distribution of the soil content, organic matter in this realm can be generated independently without the specific information of soil content, we provide two components (dependent-version and independent-version) that work similarly to generate the diagram of the soil's surface organic matter:

dependent version

The dependent version (top) use output of from the component Soil Interior Organic Matter, so that the density of the two parts match automatically.

independent version

The independent version (bottom) use the output from the component Soil Base, allowing the user to freely define the parameters.

Example S3

Download the GH file

This example demonstrates the usage of Soil Interior Organic Matter and Soil Surface Organic Matter components to visualize organic matter.