Prioritizing ecosystem services in rapidly urbanizing river basins: A spatial multi-criteria analytic approach

• Spatial MCA involving scenarios, hydrologic modeling, preference weighting, and optimization.
• Application to regional spatial planning in metropolitan Jakarta, Indonesia.
• Flood mitigation and erosion control threatened by future land use change.
• Service bundles offer synergies that might not be realized under sector-based strategies.
• Our approach is useful in areas experiencing rapid land use change.

Spatially explicit information on ecosystem services can be an important input to regional spatial planning, but must be framed in a particular social context in order to be useful. We present a case study in metropolitan Jakarta, Indonesia, where stakeholders are discussing a spatial plan to help mitigate flooding risk, conserve scarce agricultural land, and restore forests in the upper catchment areas. We demonstrate an application of a four-step spatial multi-criteria analytical (MCA) approach that involves scenario development, ecosystem service quantification and mapping, preference weighting, and optimization to maximize preferred ecosystem services while minimizing cost. We improve upon similarly-oriented MCAs by incorporating information on ecosystem service potential, supply, beneficiaries, and likely costs to conserve them, with the aim of assisting stakeholders in negotiating future land development. Stakeholder-weighted preferences provide information on potential areas of conflict or agreement, but the aggregated weights do not have a significant impact on the optimization model's outputs. Our results also reveal possible synergies between, for example, biodiversity conservation and erosion control, which are typically considered and planned for by separate stakeholder groups. We also find that if we include monetary estimates of flood damages by sub-basin and population data by groundwater basin, optimal solutions include more expensive interventions when compared to a model omitting this information. Overall, our approach offers a transparent way to collect and process relevant information on regional ecosystem services, and can be particularly useful in areas where land use is changing rapidly and land use controls are either weak or decentralized.