Identifying potential service flow and actual service flow: Source-flow-sink-use framework and case study.

Area of Science:

• Ecology
• Environmental Science
• Spatial Analysis

Background:

• Ecosystem service flows (ESFs) assessment and management require understanding the delivery chain from generation to utilization.
• Spatial characteristics and interconnections within the ESF delivery chain have been under-examined.

Purpose of the Study:

• To propose and apply a source-flow-sink-use framework to analyze freshwater supply service (FS) delivery chains.
• To quantify potential and actual freshwater flows, and to develop improved freshwater security indexes (FSI).
• To reveal spatial patterns of freshwater supply security.

Main Methods:

• Developed a source-flow-sink-use framework distinguishing potential and actual service flows.
• Quantified supply, demand, potential flow, actual flow, flow depletion, and storage of FS at multiple scales.
• Improved freshwater security indexes (FSI) and mapped regional freshwater supply security patterns.

Main Results:

• Potential service flow showed a west-low, east-high pattern; actual service flow was lower with greater spatial heterogeneity.
• Static, potential, and actual FSI revealed distinct freshwater supply security patterns: slight surplus, surplus, and southern surplus with northern deficit.
• The study provides a quantitative basis for understanding ESFs and their management.

Conclusions:

• The source-flow-sink-use framework enhances ESF assessment by incorporating spatial dynamics.
• Findings offer crucial insights for spatial planning and ecosystem management, particularly for freshwater resources.
• This research contributes to a more comprehensive understanding of ecological processes in service delivery.