Assessment of urban water security based on catastrophe theory

Abstract

In this study, a model for assessing urban water security is developed using an evaluation method of catastrophe theory. To overcome the defects of the traditional catastrophe evaluation method, two aspects of improvement are assessed. One is expanding the scope of application of the traditional catastrophe approach, i.e., new normalization formulae for five lower level indicators contained in the index at the higher level is proposed in theory. The other is solving the problem that the synthetic values are generally high and the differences are not obvious based on the theories of Cramer's Rule and Vander monde determinant. The assessment results in Wuhan city are in good agreement with the actual situation. The comparison between the results of the improved method and a fuzzy comprehensive evaluation method verifies the science and reliability of the developed method. Consequently, it is concluded that the improved method can be an effective tool for assessment of urban water security and provide a valuable reference for improving inadequacies in urban water security.

Comprehensive assessment and hierarchical management of the sustainable utilization of urban water resources based on catastrophe theory

“…Therefore, it is not possible to verify the obtained results with the findings of previous studies. But similar works have been done to study water security [21,22] and ground water potential zones [25]. These researches were to develop a means of quantifying the systems over time, the same as our work.…”

“…So the method avoids the subjective in weight decisions. Due to its dialectic characteristics and advantages as a simple mathematical construct with clear physical meaning, the catastrophe theory has been widely employed in multi-index comprehensive assessment studies, such as, coal and gas outburst prediction [20], water security [21,22], land ecological security [23], rural information level [24], ground water potential zones [25], and insect pest control [26]. We argue that the change of utilization of water resources state can be considered as a particular catastrophic behavior, a small and gradual change in the steady equilibrium state of a sub-system can rapidly cause the whole system to reach the crush state.…”

Examining Water Security in the Challenging Environment in Togo, West Africa

“…The catastrophe evaluation method was improved by Reference [37] with the purpose of accommodating sub-systems to have high-level indicators (more than four) and incorporate the gradations of evaluations' samples. The multi-criteria evaluation method consists of three steps: (1) dividing the system into sub-systems, parameters, and then indicators (organized in each sub-system based on the their inner logic relationships and their importance) [35], (2) normalizing the initial data obtained using catastrophe theory and fuzzy mathematics (based on the adequate catastrophe model) [38], (3) finalizing the value of each subsystem based on the principle of a minimum value or the principle of a mean value (depending on whether the indicators are complementary to each other or interchangeable within one system) [35].…”

River–human harmony model to evaluate the relationship between humans and water in river basin

“…Since the dimensions are too abstract to be measured directly, they should be divided into basic indicators. Yang et al 8 have summarized the indicator selection criteria, that is, the indicators should be theoretically well-founded, clear in content, relatively stable and independent, measurable and comparable, easy to quantify, regionally specific and acquirable. When selecting the indicators in this study, we primarily considered the diversity of data, availability and integrity.…”

“…Hence, for a few decades the focus of discussion has been the imbalance of relationship between humans and river. The conflicts have been indicated as water vulnerability, water poverty, water deterioration, water scarcity and water security [5][6][7][8] . In recent times, more and more countries are facing water-related problems; these are not limited to countries lacking water, but also to water-rich countries 9 .…”