Keywords
global limits, world water models, prim, exploratory modelling
Start Date
1-7-2012 12:00 AM
Abstract
Safe operating space for human activities that will not push the planet out of the ‘Holocene state’ that has seen human civilizations arise, develop, and thrive can be defined with respect to among others global freshwater use. Establishing such limits is a methodological challenge because they are critically depended on local conditions, the role of management, and financial and institutional capacity in magnifying or ameliorating problems. Moreover estimates of these limits are plagued by uncertainty arising out of conflicting models, regional variations, limitation of expansion of water use through financial and institutional capacity, and uncertainty about the realization and efficiency of trans-boundary water transfers. This paper aims at investigating the limits to global freshwater use through exploratory modelling and analysis. To this end, the behaviour of a dynamic world water model that also included the socio-economic system is explored across a wide variety of uncertainties. The resulting dynamics are analysed and dynamics indicative of water shortage are identified. In order to identify the conditions for occurring of these dynamics, we use the Patient Rule Induction Method (PRIM). PRIM can be used for data analytic questions where the analyst tries to find simultaneous combinations of values for input variables that result in similar characteristic values for the outcome variables. Specifically, one seeks a set of subspaces of the input variable space within which the values of output variables are considerably different from the average value over the entire input domain. In as far as these output sub-spaces are indicative for unsustainable water conditions, the boundaries of their congruent input parameter spaces constitute limits to global fresh water use.
Safe Operating Spaces for Human Water Use: Applying Exploratory Modeling and Patient Rule Induction to ANEMI
Safe operating space for human activities that will not push the planet out of the ‘Holocene state’ that has seen human civilizations arise, develop, and thrive can be defined with respect to among others global freshwater use. Establishing such limits is a methodological challenge because they are critically depended on local conditions, the role of management, and financial and institutional capacity in magnifying or ameliorating problems. Moreover estimates of these limits are plagued by uncertainty arising out of conflicting models, regional variations, limitation of expansion of water use through financial and institutional capacity, and uncertainty about the realization and efficiency of trans-boundary water transfers. This paper aims at investigating the limits to global freshwater use through exploratory modelling and analysis. To this end, the behaviour of a dynamic world water model that also included the socio-economic system is explored across a wide variety of uncertainties. The resulting dynamics are analysed and dynamics indicative of water shortage are identified. In order to identify the conditions for occurring of these dynamics, we use the Patient Rule Induction Method (PRIM). PRIM can be used for data analytic questions where the analyst tries to find simultaneous combinations of values for input variables that result in similar characteristic values for the outcome variables. Specifically, one seeks a set of subspaces of the input variable space within which the values of output variables are considerably different from the average value over the entire input domain. In as far as these output sub-spaces are indicative for unsustainable water conditions, the boundaries of their congruent input parameter spaces constitute limits to global fresh water use.
