The Dissolve Boundaries tool aggregates features based on specified attributes. One or more fields can be selected to merge areas with matching attribute values.

## Workflow diagram

## Example

- An agricultural development company sampled thousands of terrestrial quadrats across a county. The data includes a soil_depth field and a suitability field. The values in the suitability field were calculated by classifying soil_depth values into categories of low or high. The quadrats can be dissolved based on the suitability field to determine where the most expansive suitable area is located.

## Usage notes

- The input must be a single layer of polygon features. The dissolved output features will always be polygon features.
- The tool has the option to calculate statistics on numerical fields for areas that are being dissolved together.
- Output from the tool can include multi-part or single part features. A multi-part feature is defined as one feature that is broken up into noncontiguous parts. For example, the state of Hawaii could be considered a multi-part feature because its separate geometric parts are classified as a single state.
- If no field(s) are entered in the Dissolve Fields parameter and Multi-part is set to Yes, the output will be one multi-part feature. If no field(s) are entered in theDissolve Fields parameter and Multi-part is set to No, only polygons that intersect will be merged.
- Additional statistics can be calculated using the Summary Fields parameter. The summary fields statistics available depend on the field type you are summarizing. A string attribute field can utilize the statistics ANY, COUNT, and COUNT DISTINCT. A numeric attribute field can use the statistics ANY, COUNT, COUNT DISTINCT, SUM, SUM OF SQUARES, MIN, MAX, RANGE, VARIANCE, and STANDARD DEVIATION. A date attribute field can utilize the statistics ANY, COUNT, MIN, MAX, and RANGE.

## Parameters

Parameter | Description | Data Type |
---|---|---|

Input Layer | The point features for which density will be calculated. | Features |

Dissolve Fields (optional) | The field or fields on which to aggregate features. Features with the same field values will be dissolved. | String |

Summary Fields (optional) | The statistics that will be calculated for specified fields. Different statistics are available depending if the specified field is a string, numeric, or date field. - ANY - This is a sample string from a field of type string.
- COUNT - Calculates the number of nonnull values. It can be used on numeric fields or strings. The count of [null, 0, 2] is 2.
- COUNT DISTINCT - Calculates the number of distinct, nonnull values. It can be used on numeric fields or strings. The count distinct result of [null, 4, 3, 4] is 2.
- SUM - The sum of numeric values in a field. The sum of [null, 1, 3] is 4.
- SUM OF SQUARES - The sum, over all observations, of the squared differences of each observation from the overall mean. The sum of squares of [null, 2.2, 3.1, 4.7] is 3.206.
- MIN - The minimum value of a numeric field. The minimum of [0, 2, null] is 0.
- MAX - The maximum value of a numeric field. The maximum value of [0, 2, null] is 2.
- MEAN - The mean of numeric values. The mean of [0,2, null] is 1.
- RANGE - The range of a numeric field. This is calculated as the minimum value subtracted from the maximum value. The range of [0, null, 1] is 1. The range of [null, 4] is 0.
- VARIANCE - The variance of a numeric field in a track. The variance of [1] is null. The variance of [null, 1,1,1] is 1.
- STANDARD DEVIATION - The standard deviation of a numeric field. The standard deviation of [1] is null. The standard deviation of [null, 1,1,1] is 1.
| String |

Multi-part | Specifies whether multi-part features are allowed in the output layer. A multi-part feature is defined as one feature that is broken up into noncontiguous parts. - Yes - The output will create any multi-part features if applicable.
- No - Only single part features will be created in the output.
| Boolean |

## Output layer

The output layer will contain:

- Any fields specified in the Dissolve Fields parameter.
- COUNT field which represents how many were features were dissolved into that feature.
- Any Summary Fields configured in the tool.

## Considerations and limitations

The Dissolve Boundaries tool can be used on polygon features only.