Spatiotemporal Characterization of Land Cover Impacts on Urban Warming: A Spatial Autocorrelation Approach

Round 1

Reviewer 1 Report

• 88  Our study focuses on the Boise-Meridian metropolitan region with a total population of more  than 23 million in 2017 [22].  => 2.3 million ??, check the number

• Figure 1. Study area located in the Boise-Meridian metropolitan region, Idaho. => What does the red colored part mean?

• 189 between the LST and the three spatial 188 autocorrelation indices – G of NDVI, G of NDBI, and local Moran’s I of NDVI. => Why are NDBI and Moran’s I omitted?
• Figure 5. => In general, the results of G and Morans'I are mapped using GIS software, but not the graphs.  Maps should also be presented for analysis results such as spatial autocorrelation, if you want to present the clustered or hotspot region.
• 421 Our statistical analyses identify a cooling effect from green vegetation and a warming effect from built-up areas, both of which had intensified over time. => Maps should also be presented for analysis results such as spatial autocorrelation, if you want to present the clustered or hotspot region such as built-up areas or cooling effect areas.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

This manuscript adds to already burgeoning literature on urban heat island (UHI) effects and is presented more a case study application of UHI on the Boise-Meridian Metropolitan Area, almost following similar methodology as in the case of Phoenix and other desert cities. This beg a question: What is the novelty of this manuscript other than to present a case study on a perhaps less studied city like Boise? 

One way to highlight the novelty of this manuscript is to highlight how this research developed a methodology of applying spatial autocorrelation indices (although not new) with land cover maps depicting spatial configuration at a landscape level. Although this method has been tested elsewhere (i.e., not new), it offers a contrast to the conventional method of relying on landscape matrices. This should be clearly communicated in the abstract as well as in the introduction section (perhaps within the first two paragraphs) to highlight why the readers should pay attention to this study (not just for Boise case, but also for its methodological advances). 

There are a few other comments, which I hope will help improve the quality of this manuscript:

1) In Urban-rural gradient analysis: it has four different direction;however, this method assumes a concentric zone built-up development. In most cases in the US southwest, urban growth do not follow this fix path of urban growth radiating outwards—some cities have follow the concentric zone patterns while others have witnessed coalescing of small cities into a metropolitan city, in which four direction sampling strategy would be less helpful (see Zhang et al 2013). Perhaps synthesizing why did the authors chose this over other sampling types could make the sampling strategy more credible.

Zhang, S., A York, C. Boone, and M Shrestha. 2013. Methodological Advances in the Spatial Analysis of Land Fragmentation. Professional Geographer, 65(3): 512-526. DOI: 10.1080/00330124.2012.700501

2) Selection of spatial autocorrelation to quantify landscape patterns: That is a great method to examine spatial characteristics (e.g., land surface temperate, land systems) but the authors need to be cognizant of the fact that spatial autocorrelation violates a fundamental theory of randomization in spatial statistics, which means the sample selected (any unit of analysis) that are near to each other are likely to similar to other and there could be biases in signature classification. This also means there are likely to be inherent biases in discrete categorization of land cover type selected in the analysis. Just mentioning the limitation would be an honest thing to do and would not devalue the significance of this study.

There are areas, especially in the introduction section, where more careful editing could help improve the quality of this manuscript. The first three paragraphs do not offer anything that is not already known in the UHI. Perhaps starting with how the conventional UHI studies' reliance on the landscape matrices is problematic could serve as a sound rationale for this manuscript than as a case of Boise (which did not seem to be unique other than urban growth pattern following the railway line).

There is also some minor copy-editing that this manuscript could use. For instance, it is a good idea to replace gender insensitive terms like "Man-made" to a gender-neutral word "human-induced" or "human-dominated." 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf