# Multidimensional Assessment of Lake Water Ecosystem Services Using Remote Sensing
## 5 Conclusions  
We conducted a comprehensive, long-term, multidimensional ecosystem service assessment that can potentially benefit policymakers. First, we revealed some neglected degradations in traditional output-based assessment, such as the water provisioning capacity per unit of surface water is flimsy, and the number of counties with degradation is increasing. Second, we identified the relatively stable distribution of water provisioning services during 1998-2018 and the various spatial clustering patterns from three dimensions. Third, we revealed the dependence between high-level efficiency and high-level output, low-level output, and low-level efficiency, which could potentially be used in the water resources utilization and ecosystem service management. Fourth, we identified nine severely degraded counties and revealed that the Western Minnesota counties are more degraded than the others, which is particularly important to the sustainable ecosystem utilization and ecological services enhancement. Last but not least, we modeled the relationships between the principal influencing factors and the multidimensional assessment results, which reveals that human activities impact water provisioning services in Minnesota more than climate changes.  
In summary, the contributions of this study are as follows: First, we expanded the perspective of ecosystem services assessment from 'output' to an 'output-efficiency-trend' multidimensional framework, measuring the provisioning capacity of ecological services per unit area of the ecosystem and the trend while assessing the output. Thus, we revealed some degradations which could not be identified in traditional output perspective assessment. Secondly, we identified the priorities for policymakers to underpin better protection of lake ecosystems; the higher the degradation level of a county, the higher the priorities it should have. Finally, we revealed that human activities have a more substantial impact than climate change on output and should be paid more attention to output enhancing policy formulation and management implementation. While efficiency and trend are more sensitive to climate changes than human activities, combat climate-changing measures are essential for improving efficiency and development.  
The following are available online at [[https://www.mdpi.com/article/10.3390/rs13173540/s1](https://www.mdpi.com/article/10.3390/rs13173540/s1)]([https://www.mdpi.com/article/10.3390/rs13173540/s1](https://www.mdpi.com/article/10.3390/rs13173540/s1)), Table S1: Multidimensional assessment spaces and their properties, Table S2: The F test reference table.  
Conceptualization: Q.W. and D.S.; methodology, Q.W. and D.S.; software, Q.W. and D.S.; validation, Q.W., D.S. and Y.S.; formal analysis, Q.W.; investigation, D.S.; resources, Q.W. and D.S.; data curation, D.S.; writing--original draft preparation, D.S.; writing--review and editing, Q.W. and Y.S.; visualization, D.S.; supervision, Q.W.; project administration, Q.W. and Y.S.; funding acquisition, Y.S. All authors have read and agreed to the published version of the manuscript.  
This research was supported by the Technology Innovation Center for Land Spatial Eco-restoration in the Metropolitan Area, MNR, Shanghai, 200003 (Project number: CXZX202004). We would also like to thank the China Scholarship Council for sponsoring [PERSON] to study at the University of Tennessee as a visiting scholar.  
Not applicable.  
The data presented in this study are available on request from the corresponding author.  
We thank the anonymous reviewers for their constructive comments that greatly improved the quality of our manuscript.  
The authors declare no conflict of interest.