About#

The PEM Project (Planejamento Espacial Marinho do Brasil, or Marine Spatial Planning for Brazil) is a national initiative aimed at developing spatially explicit guidelines for the sustainable and strategic use of the Brazilian marine environment.

This page provides a conceptual overview of the general workflow, which forms the core of the PEM methodology and underpins all regional plans.

By following this structured and data-driven workflow, the PEM methodology ensures reproducibility, transparency, and scientific robustness in the assessment of marine spatial planning outcomes.

All analytical steps are implemented through R and Python scripts, available in this repository, which can be adapted for different regions and data resolutions.

See also

For implementation details see the User Guide

PEM Workflow#

The PEM workflow represents the most abstract and reproducible component of the PEM method.

It begins at a zero level of information, where only spatial data are available, and transforms these datasets into spatially explicit indicators and decision-support maps.

Input Data#

At the foundation level, the workflow integrates diverse spatial datasets, including:

  • Bathymetry – ocean depth and seabed morphology.

  • Habitats – distribution and characteristics of marine ecosystems.

  • Uses of the ocean – spatial footprint of human activities across sectors such as fisheries, energy and transportation.

  • Coastal hubs – ports, cities, and infrastructure nodes that influence or depend on marine uses.

These datasets serve as the basis for constructing higher-level spatial information layers.

Management and Planning Units (UPG)#

An important component of the PEM workflow is the creation of Management and Planning Units (UPG) — spatial zones that organize and guide marine management actions.

These units are derived from input data such as bathymetry, habitats, and coastal uses, combined with expert-defined thresholds for distance, depth, and sensitivity. The process groups similar areas into nested spatial units, allowing analysis and planning at multiple scales.

UPGs are used to support decision-making and scenario analysis, ensuring that management strategies reflect ecological patterns, human activities, and the connectivity between land and sea.

Spatial Indexes#

Through a series of converging analytical processes, the raw data are transformed into three key spatial indexes, each representing a different dimension of marine use performance:

  1. Benefit Index (B) — quantifies the economic and social benefit derived from the use of each spatial unit of the ocean.

  2. Habitat Risk Index (R) — captures the environmental fragility and sensitivity of marine habitats exposed to human activities.

  3. Conflict Index (C) — expresses the intensity of overlap or competition between different marine uses within the same area.

Each of these index is calculated as a relative measure, allowing comparisons across spatial scales and scenarios of marine use.

Integrated Performance Index#

The core integrative indicator of the PEM framework is the Marine Use Performance Index, or IDUSE-Mar (Índice de Desempenho do Uso de Serviços Ecossistêmicos do Mar). This index synthesizes the three dimensions—benefit, risk, and conflict—into a single expression of marine use performance:

\[D = \frac{B}{R \times C} \quad \text{where } D \in [0, 1]\]

Where:

  • \(D\) is the performance of marine use;

  • \(B\) is the benefit;

  • \(R\) is the risk; and

  • \(C\) is the conflict.

A higher value of \(D\) indicates a more sustainable and efficient use of the marine space—high benefits with relatively low risk and conflict.

Benefit Index#

The benefit index is derived from the spatialized intensity and value of marine uses. It aggregates sectoral information into a normalized economic density indicator:

\[B = \sum_{j = 1}^{N} \mathcal{B}(U_j) \quad U \in \mathbb{U}\]

Where \(U_j\) represents each use sector \(j\).

For each municipality \(i\) and time step \(t\), the benefit is computed as a function of local value and activity:

\[B_{i, j, t} = f(V_{i, t}, U_{j, t}), \quad B \in [0, 1]\]

Each sectoral benefit \(B_j\) is normalized such that:

\[\sum_{i = 1}^{N} B_i = 1\]

Habitat Risk Index#

Risk (R) — follows the conceptual structure of the InVEST Habitat Risk model, estimating the likelihood of impact based on exposure, consequence, and habitat sensitivity.

Conflict Index#

Conflict (C) — measures spatial incompatibility or overlap between uses, reflecting competition for marine space or interference between activities.

Scenario-Based Analyses#

All indices (\(B\), \(R\), and \(C\)) are computed for specific use scenarios. Scenarios may represent current conditions, projected developments, or management alternatives, allowing the IDUSE-Mar to serve as a comparative tool for evaluating policy or spatial planning options.