IWRM Incorporating Water Use and Productivity Indicators of Economic Clusters Using a Hydro-Economic SDSS

Reviewer 1

The study presented in the text is focused on the application of a spatial decision support system (SDSS) to analyze allocation decisions in four interlinked basins in Northeastern Brazil during a period of water scarcity. The authors used an innovative method of allocation that simulates the use of economic instruments by using hydro-economic indicators as economic weights of hotspots and individual users for water allocation.

The normalized concentration index and exploratory spatial data analysis were applied to socioeconomic data to identify hotspots in economic sectors. The economic allocation transfers water from Agriculture and Industry to the Services sector, which is justified given the low indicators of the main sectors of Agriculture and Industry in the region. Additionally, the regional transfer results show that without using economic criteria and maintaining the current distribution network, there is a transfer of water stored in drier to humid regions.

Overall, the study presented in the text seems to be well-conducted and provides valuable insights into the use of a spatial decision support system for water allocation in a region experiencing water scarcity. The application of economic weights to hotspots and individual users for a water allocation is an innovative approach that could be useful in other regions facing similar challenges. However, it would be helpful to have more information on the specific hydroeconomic indicators used in the study and their selection criteria. Additionally, the potential limitations and uncertainties associated with the application of the SDSS should be acknowledged and discussed.

Thank you for your review and evaluation. We have taken into account all your suggestions and changed the manuscript accordingly. Please see below the list of changes or answers to each point raised.

Related to the more information required on the hydroeconomic indicators used, we have included the sentence below at the end of the paragraph starting from the line 242 associated to the water use indicators.

“Thus, these two indicators can support managers in monitoring goal 6.4 (FAO 2018) as this goal is associated with an increase in the efficiency of water use in all sectors, as well as a substantial reduction in situations of water stress “

Moreover, after presenting all the indicators used and their weights, we have included a paragraph (see below) (from line 281) related to the potential of the SDSS to generate other indicators and weight them through a friendly-user interface:

“Obtaining such indicators was only possible due to the platform that integrates water allocation with economic models, which manages to associate water use with socio-economic data (jobs and income). Other indicators from that platform can be obtained and used, as well as different weights for each one can be chosen by managers. The SDSS foresees the development of new functionalities in a friendly interface that allows the user to generate other hydro-economic indicators, as well as change the weights of each one to obtain other new results that can support the allocation decision in situations of scarcity”

Please separate the discussion and conclusion sections of the manuscript to avoid confusion. Also, include a way forward.

We separated the discussion and conclusion sections of the manuscript. Furthermore, we extended the conclusion and added a way forward,

Reviewer 2

The manuscript is well written with aims and objectives clearly defined. The results are well presented and supported by Figures and Tables. However, the title is too lengthy, and would suggest refining it to make it shorter.

Thank you for your review and evaluation. We have taken into account all your suggestions and changed the manuscript accordingly. Please see below the list of changes or answers to each point raised.

Please see below the list of changes or answers to each point raised.

We changed the title to:

“IWRM incorporating water use and productivity indicators of economic clusters using a hydro-economic SDSS”

In page 2 Line 66-67: A platform linking a network-based system model to an economywide model, made available in a Spatial Decision Support System (HEAL System). What does HEAL indicate? Usually, we write Spatial Decision Support System as SDSS.

HEAL is an abbreviation for our SDSS. We added the full text for the abbreviation (Hydro Economic Allocation System - HEAL).

In page 5, Line 206: Hotspot Analysis determines the Getis-Ord Gi* statistic. Please justify the application of Getis-Ord Gi* in this analysis compared to Kriging (KDE) analysis

Our aim was to determine statistically significant economic cluster (selection of a group of municipalities). Therefore, we have chosen the Getis-Ord Gi*, which calculates a Z score and P value for each municipality in the study area. The used economic data was only available at this municipality level (defined by boundary polygons of the municipalities); therefore, the extent is pre-defined. Clarification: Weighting is applied to water users within the sectorial hotspot limit. The chosen method captured local (known and unknown) hotspots (group of municipalities) very well. KDE is non-parametric, it does not identify statistically significant hotspots and is more used to create a smooth distribution (using an extent which has to be defined), this method would fit better if economic data/weighting were directly on user level (point data) – seems an interesting different approach for water allocation. We changed the already given explanation for Getis-Ord Gi* and made clearer that it was a preferred chosen method, considering the objective and available data.

In page 5: Figure 2, User weighting ....... slightly blurry.

We improved the Figure and increased the Font Size in the manuscript; however, we have also submitted a high-resolution image to the editor this should also fix the problem.

In Materials and Methods: What is the justification for taking into consideration a specific drought period (2012-2018) in Northeast Brazil? The study does not mention any other historical drought period in the study area.

The word “Specific” is misleading, we changed it to “the latest severe”.

In Table 1 and 2 the fonts are different from Times New Roman, same for Figure 5. Should be consistent.

We changed the font to combine with the manuscript.

Reviewer 3

The paper is well-written and structured. The sections are logically designed. The research question and method were well presented, as well as the result section. It would be great if the authors improved/extended the discussion section. Overall, I suggest the paper for publication.

Thank you for your review and evaluation. We have considered all your suggestions and changed the manuscript accordingly. Please see below the list of changes or answers to each point raised.

We separated the discussion/ conclusion sections of the manuscript and greatly improved/extended this section of the manuscript.

A minor comment about figure1, Please show the study area in Brazil.

We’ve added the case study area in Brazil (Figure 1).