Including Variability across Climate Change Projections in Assessing Impacts on Water Resources in an Intensively Managed Landscape

Round 1

Reviewer 1 Report

Please see the attached.

Comments for author File: Comments.docx

Author Response

Thank you for the kind suggestions which help us improve the manuscript. Please see the attached document for detailed response. 

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper reports on a study that demonstrates how combining stochastic weather generators and future climate projections can support efforts to assess future risks of negative water resource outcomes.  This study develops an ensemble approach for creating daily climate realizations combining a stochastic weather generator and downscaled General Circulation Model (GCM) projections. The generated ensemble of climate data is then used to drive an integrated socio-hydrologic model using the Envision 418scenario-based modeling framework. 

 

The paper is well-written and well-structured and is within the scope of the Journal and may be of potential interest to the audience of the Journal. However, I suggest the authors to take into account the following major considerations.

 

·      The authors develop and apply a framework for combining statistically downscaled outputs from multiple GCMs with a stochastic weather generator to quantify the impacts of climate change on a coupled socio-hydrologic system in a probabilistic fashion.They state that currently available downscaled datasets used for climate change impacts studies at regional scales, but may not adequately capture uncertainties within climate models in ways that can support robust quantification of the uncertainties in important outcomes like insufficiencies in water supply.  However, my major concern is that the authors did not describe the uncertainties that manifest in the study at all. I would like to see a description of uncertainties that may be related to the coupled socio-hydrology systems model, but also a critical reflection on their policy implications in the Discussion section.

·      Regarding the to the coupled socio-hydrology systems model, made some assumptions, which need more explanation or follow up in the discussion

o  “While future changes in water rights depend on future real estate transactions, growth in the extent of urban areas, and potential changes in water rights laws, we assume that the attributes of the water rights data remain the same over time” Lines 67-69.Lines 70-72. I can imagine that the water rights data remain the same within a time frame of 20 years but the study applies time horizon that exceeds 20 years. Given that the author investigate an intensively managed region, this argument may not hold. So please provide a more solid argumentation on how to account for this.

o  “Further, we do not take into account technological changes that may significantly increase water use efficiency in the agricultural sector and lead to a lower irrigation water demand and actual water use in the future” Lines 70-72. I would like to see a critical reflection on the potential impact of technological changes on the results of this study.

 

Minor points:

·      Line 65: what are forcing realizations?

·      Lines 94-95: please add that the PAST scenario is the baseline scenario

·      Line 120: please use “subject to”

·      In the figures, the graph for RCP4.5 and RCP8.5 are hard to distinguish in black and white mode, please use dashed lines

Author Response

Thank you for the kind suggestions which help us improve the manuscript. Please see the attached document for detailed response. 

Author Response File: Author Response.pdf