Water Resources Research Act Program

Details for Project ID 2014HI433B

Managing for multiple ecosystem services with changing land use in West Maui

Institute: Hawaii
Year Established: 2014 Start Date: 2014-03-01 End Date: 2016-02-28
Total Federal Funds: $20,208 Total Non-Federal Funds: $40,627

Principal Investigators: Kirsten Oleson

Abstract: Problem: Land-based sediments and nutrients have a direct impact on the water quality of coastal Hawaii, and pose one of the biggest threats to the health of shallow coral reefs ecosystems in the main Hawaiian Islands. Land use changes, including transitions from agriculture to urban development, are a major driver of water quality changes. Managers in west Maui recognize the need to balance development and conservation goals. Past and future development will affect important ecosystems that deliver benefits to humans. These benefits are known as ecosystem goods and services. Despite ongoing management actions, there is a critical unfulfilled need to evaluate the potential trade-offs posed by alternative resource management strategies across a broad suite of threats, resource uses, ecosystem services, and stakeholder groups. Approach: To provide a way to evaluate trade-offs in the management of coupled ecological and socioeconomic systems, we are building a decision-making tool that quantifies, maps, and values ecosystem goods and services. Our initial focus is on hydrologic ecosystem services including water quantity and quality, and sediment and nutrient retention. Our decision-support tool will be able to reveal the biophysical impacts (erosion, runoff, infiltration) that result from specific land management actions (e.g., land use, adoption of best management practices, restoration). The primary goal of this proposal is to address the need by managers for decision support tools by providing key research support to the model development process. The project is comprised of two field studies designed to provide key needed data: Biophysical: We will collect field data to parameterize and calibrate more accurate hydrological models, including sediment and nutrient retention and groundwater recharge modules. In order to most effectively model watershed hydrology and sediment transport processes, detailed data sets reflecting vegetation cover, land use, and soil properties (such as infiltration capacity and erodibility) are necessary. Field surveys that can ground truth aerial and satellite imagery are necessary to qualitatively assess an assumption of the sediment models. In addition, tailored land use maps are needed to most effectively create management units that can be used for decision-making. Economics: We will design a valuation study focused on key hydrologic ecosystem services important for Hawaii that are linked to water quality: tourism and recreation. The study will be designed to collect information on people’s willingness-to-pay for improved visibility, reduced frequency of beach closures, and thriving coral reefs. Each of these is a predicted outcome of better land management. Our biophysical models are aimed at quantifying these impacts. Possessing the economic values will enable us to assign an economic value to the ecological improvements achieved from different land management strategies. Outputs: The data collected and analyzed in this project will serve to build a better decision support tool for use specifically in Hawaii and similar tropical montane environments. The tool will be able to compare across multiple ecosystem services and facilitate understanding of tradeoffs between management strategies and the potential impacts to hydrological ecosystem services. The proposed outputs of the project include:  An improved decision support tool tailored for Hawaii's unique hydrological conditions  A GIS-based map of source areas of sediment in the Wahikuli and Honokowai watersheds  A spatial assessment of nutrient concentrations in the soils and sediments of the watershed  Summary of recommendations for changes to hydrologic models that describe sediment export  Non-market valuation methods for ecosystem services related to water quality developed, tested, and applied  Visitation distribution and statistics to key beach zones  Estimates of beach users’ willingness-to-pay for water quality-related coastal ecosystem services