Elsevier

Science of The Total Environment

Volume 572, 1 December 2016, Pages 1269-1280
Science of The Total Environment

A novel substance flow analysis model for analysing multi-year phosphorus flow at the regional scale

https://doi.org/10.1016/j.scitotenv.2015.10.055Get rights and content

Highlights

  • We developed a model for analysing multi-year phosphorus (P) flow at the regional scale.

  • The model includes all key systems and subsystems of P flow at the regional scale.

  • The model can indicate the changes and trends in P flow over many years.

  • The model allows necessary modifications and can include any degree of complexity.

  • The model can provide vital information to make improved P management decisions.

Abstract

Achieving sustainable management of phosphorus (P) is crucial for both global food security and global environmental protection. In order to formulate informed policy measures to overcome existing barriers of achieving sustainable P management, there is need for a sound understanding of the nature and magnitude of P flow through various systems at different geographical and temporal scales. So far, there is a limited understanding on the nature and magnitude of P flow over multiple years at the regional scale. In this study, we have developed a novel substance flow analysis (SFA) model in the MATLAB/Simulink® software platform that can be effectively utilized to analyse the nature and magnitude of multi-year P flow at the regional scale. The model is inclusive of all P flows and storage relating to all key systems, subsystems, processes or components, and the associated interactions of P flow required to represent a typical P flow system at the regional scale. In an annual time step, this model can analyse P flow and storage over as many as years required at a time, and therefore, can indicate the trends and changes in P flow and storage over many years, which is not offered by the existing regional scale SFA models of P. The model is flexible enough to allow any modification or the inclusion of any degree of complexity, and therefore, can be utilized for analysing P flow in any region around the world. The application of the model in the case of Gippsland region, Australia has revealed that the model generates essential information about the nature and magnitude of P flow at the regional scale which can be utilized for making improved management decisions towards attaining P sustainability. A systematic reliability check on the findings of model application also indicates that the model produces reliable results.

Introduction

Phosphorus (P) is an indispensable nutrient requirement for plant growth, hence, an essential element for sustaining global food production. The modern global agricultural/food production system is heavily reliant on a substantial input of P as chemical fertilizer which is primarily sourced from the mining of phosphate rock (PR), a non-renewable and finite resource. The lifetime of global reserves of PR is uncertain, and estimates range from one to a few hundred years (Cordell et al., 2009, Vaccari, 2009, Van Kauwenbergh, 2010, Cooper et al., 2011, Cordell and White, 2014). Perhaps more importantly, these global reserves are geographically restricted to a few countries, and therefore, the majority of countries rely on P import to sustain their food production (USGS, 2014). Studies (Cordell et al., 2009, Schroder et al., 2010, Childers et al., 2011, UNEP, 2011, Metson et al., 2012, Scholz et al., 2014, Chowdhury, 2015) suggest that there exists a number of challenges for the global P resource, for instance, dwindling reserves and increasing demand, geopolitical constraints, excessive loss, and high discharge to water bodies; which if not properly tackled may lead to P scarcity in many countries and hamper global food security. The sustainable management of P is essential not only for global food security but also for minimizing P induced pollution of water bodies and associated harmful consequences (Carpenter, 2008, Conley et al., 2009, Smith and Schindler, 2009, Xu et al., 2010, Conley, 2012).

In order to provide informed and effective policy and management response to overcome these challenges, there is a need for a sound understanding of the nature and magnitude of P flow through various systems at different geographical and temporal scales. Taking this important fact into consideration, efforts are already underway, and a number of substance flow analyses (SFAs) of P have been performed for the quantitative assessment of P flow in different systems around the world. Our in-depth and systematic review of recent SFAs of P at different geographical and temporal scales (Chowdhury et al., 2014) revealed that there is a limited understanding on the nature and magnitude of multi-year P flow at the regional scale (an agriculturally oriented region within a country) which comprises a significant mass flow of P. Therefore, this paper presents a SFA model that can be utilized for the quantitative analysis of multi-year P flow at the regional scale to provide a better understanding of the nature and magnitude of P flow for formulating improved and effective policy towards sustainable P management. This paper also briefly presents the findings of the model application in a case study along with a reliability check for these findings.

Section snippets

Methods

In order to develop the regional scale multi-year P flow model, we have systematically utilized the SFA method that applies the mass-balance principle for a systematic quantitative analysis of flows and stocks of a substance within a system defined in space and time (Brunner and Rechberger, 2004). As an effective decision support tool for P management (Brunner, 2010), in the recent times, this method has been extensively used for analysing P flow in various systems. The method for the

Results and discussion

This section explains the operational aspects of our model, the unique features that make it superior to available SFA models, its reliability in analysing P flow, and its limitations and uncertainties.

Conclusions

Utilizing the method of SFA, this study has developed a novel model in the MATLAB/Simulink® software platform that can be utilized to analyse the nature and magnitude of multi-year P flow at the regional scale. Both structurally and operationally, the model takes into account all relevant P flows and storage relating to all key systems, subsystems, processes or components, and associated interactions of P flow to represent a typical P flow system at the regional scale. One of the key advantages

Acknowledgements

We gratefully acknowledge the financial support received from the Department of Industry, Innovation, Climate Change, Science, Research and Tertiary Education (DIICCSRTE), Australia through its Australia Awards Endeavour Scholarships and Fellowships scheme. Besides, we acknowledge the financial support of the Melbourne School of Engineering, The University of Melbourne, Australia. We are also thankful to Dr. Sajeeb Saha, Research Fellow, Electrical and Electronic Engineering, The University of

References (37)

  • Z. Yuan et al.

    A bottom–up model for quantifying anthropogenic phosphorus cycles in watersheds

    J. Clean. Prod.

    (2014)
  • P.H. Brunner et al.

    Practical Handbook of Material Flow Analysis

    (2004)
  • P.H. Brunner

    Substance flow analysis as a decision support tool for phosphorus management

    J. Ind. Ecol.

    (2010)
  • S.R. Carpenter

    Phosphorus control is critical to mitigating eutrophication

  • D.L. Childers et al.

    Sustainability challenges of phosphorus and food: solutions from closing the human phosphorus cycle

    Bioscience

    (2011)
  • Chowdhury, R.B., 2015. Modelling multi-year phosphorus flow at the regional scale: the case of Gippsland, Australia....
  • D.J. Conley et al.

    Controlling eutrophication: nitrogen and phosphorus

    Science

    (2009)
  • D.J. Conley

    Ecology: save the Baltic Sea

    Nature

    (2012)
  • Cited by (0)

    View full text