Integrated Modeling Approach for Sustainable Land-Water-Food Nexus Management

Round 1

Reviewer 1 Report

The comments given already on this manuscript have been well incorporated.

 

Thank you

Author Response

(1)Improvement of the English language and style.

Re: We are grateful for the reviewers’ suggestion. We have checked the typographical and grammatical errors and polished the language.

Author Response File: Author Response.docx

Reviewer 2 Report

The authors in the revised version of the article responded and took into account most of the comments contained in the previous review. I think the authors have made great progress in terms of text quality and analysis. I have attached a few comments that should be included in the text.

Comments for author File: Comments.pdf

Author Response

(1)Please write based on how many years of observation Table 1 with meteorological data has been prepared.

Re: The meteorological data in Table 1 is based on observation data in the period of 2010-2015.

 

(2)The article should present the results of FSSR food self-sufficiency ratio calculations.

Re: The results of FSSR food self-sufficiency ratio of different crops and regions have been presented in Figure 4.

Figure 4 Food self-sufficient ratio of three-river headwaters area

 

(3)Please add more detailed information about the results to the summary.

Re: We have revised the conclusion to address this issue.

A land-water-food nexus framework with optimal allocation of agricultural water and land resources under food security and resource constraints was presented. The crop water footprint was combined with agricultural production restructuring to meet various water, land and food security constraints. A water footprint-based fuzzy fractional programming (WFFP) method was developed for sustainable land-water-food nexus management. It is superior to the existing crop planning method by incorporating crop water footprint with the optimization process. WFFP method can also tackle multi-objective by ratio optimization, which does not lead to objectively weighing multiple objectives. Fuzziness associated with the selling price and production cost of crops was effectively tackled and incorporated into the modeling process. The developed WFFP method has been successfully applied to Three (Yangtze-Yellow-Lantsang) Rivers Headwaters Region, an arid irrigation area in northwestern China, which was one of the most water-scare and ecologically vulnerable areas worldwide. The efficient utilization of agricultural water resources was given priority to crop planning and management. A WFFP model tailored to the study case was formulated with the goals to maximize economic benefits and minimize the blue water footprint at fields under the physical limitations of water and land resources.

Results show that potato and vegetables have the lowest average water footprints in TRHR, while rapeseed, highland barley, pea and wheat have the largest average water footprints. Vegetables, peas and potato should be the three most cultivated crops in the study area. Based on the daily dietary guidelines for Chinese residents, oil crops (rapeseed) and pea can basically meet local demands (Huangnan and Hainan), while the cereal was faced a huge shortage. Considering its low crop water footprints and high production capacity, Hainan and Huangnan should be planted more wheat and highland and potato, cereal shortage can be relieved to a certain extent. If following vegetable intake of residents of Qinghai Province in the period of 1984-2012 (41 kg per capita), the vegetable supply of four Tibetan autonomous prefectures can reach self-sufficiency. Optimal plans regarding crop cultivation reconfiguration with minimized crop water footprints were generated. Compared to the status quo, the optimized plan would increase economic benefits by 2% and save water by 34%, respectively, within the limit of available irrigation water.

A land-water-food nexus framework with optimal allocation of agricultural water and land resources under food security and resources constraints was presented. The crop water footprint was combined with agricultural production restructuring to meet various water, land and food security constraints. A water footprint-based fuzzy fractional programming (WFFP) method was developed for sustainable land-water-food nexus management. It is superior to existing crop planning method by incorporating crop water footprint with optimization process. WFFP method can also tackle multi-objective by ratio optimization, which does not lead to objectively weighting multiple objectives. Fuzziness associated with the selling price and production cost of crops was effectively tackled and incorporated into the modeling process. The developed WFFP method has been successfully applied to an arid irrigation area in northwestern China which was considered to be one of the most water-scare and ecologically vulnerable areas worldwide. Efficient utilization of agricultural water resources was given priority to crop planning and management. A WFFP model tailored to the study case was formulated with the goals to maximize economic benefits and minimize blue water footprint at fields under physical limitations of water and land resources. 

 

(4)A list of all marks must be added.

Re: Thanks for the reviewer’s suggestion. There are many variables used in the model, and all variables were explained for the first time of their occurrences. Therefore, a list of variables was not added.

Author Response File: Author Response.docx

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Improvement is required in the presentation language.

The interlinkages of the land-water-food nexus have not been well presented and therefore requires to be reviewed, modified The Methodology section doesn't give enough information on the proposed analyses for land-water-food nexus management and have rather extended the used model with unnecessary details to the individual parameters.

The conclusion of this paper is very narrow and therefore doesn't encourage the reader to adapt the same methods, or perhaps provide any novel information.

I would also encourage some extended statistical analyses too which shall support the overall theme and give conclusive recommendation e.g. for example 2% economic increment might be the model's less precision and you can't necessarily recommend this model to be replicated for the very benefit and redesigning or reshaping the present land use and land cover system.

Reviewer 2 Report

An interesting article presenting currently a very important problem of water resources management and their rational use. The work uses the footprint-based fuzzy fractional programming (WFFP) method to optimize crops in the studied area.

Too few references to literature. Too few references from 2015-2019. Please add about 20 references. Please check markings in formulas 7 and 8. CWU appears in these formulas. This variable has not been discussed before. Maybe this is a typing mistake. I am asking for improvement or clarification in the text. The users of CROPWAT can choose one from four alternative methods to calculate the Peff. Please describe in the work what these methods are and what they characterize. On page 8, there is no reference to the volume of food demand and the production capacity of the study area. Please write based on how many years of observation Table 1 with meteorological data has been prepared. Please present some tables in the form of charts. There are no charts at work, only tables. Please provide calculation results of crop water requirements (CWR). The article should present the results of FSSR food self-sufficiency ratio calculations. It is necessary to add a discussion of the results. Please provide in detail the results of the calculation of profits that result from the optimized area of individual crops. I am thinking of the profits resulting from the greater self-sufficiency of individual regions. It is worth considering calculations that will take into account various climate change scenarios, e.g. reducing rainfall. Please refer the obtained results to other parts of China. Please add more information about the results to the summary. The summary is currently too general. A list of all marks must be added. It should be described in more detail fuzzy fractional programming

Reviewer 3 Report

The authors have developed a great work. All the contents are perfectly explained and the basis of the water footprint for crops is improved with this fuzzy methodology.