A socio-hydrological model is used to forecast future conditions in a river basin arising from changes in climate and the economy in order to learn about macroeconomic conditions that would yield pathways for sustainable development and how they may be affected by changes in climate and the economy. The study uses a system dynamics model with endogenous social values and preferences and exogenous climate and economic drivers. Basin scale sustainability is defined as a function of economic growth, provision of environmental services and equality within the basin. The analysis reveals that a diversified basin economy is important to achieve sustainable development. Under current climate conditions, a higher level of diversification in the basin's economy increases sustainability. Higher current capital growth rates, e.g., >2% of the current rate, would also lead to more sustainable development of a kind that is less affected by the availability of water and robust to vagaries of climate change. The results suggest that policy-makers and resource managers should focus on measures to diversify the economy when it is thriving, but also consider the capacity of society to adapt to unpredictable shocks to the system.@en

Sustainable water resources management relies on understanding how societies and water systems coevolve. Many place-based sociohydrology (SH) modeling studies use proxies, such as environmental degradation, to capture key elements of the social component of system dynamics. Parameters of assumed relationships between environmental degradation and the human response to it are usually obtained through calibration. Since these relationships are not yet underpinned by social-science theories, confidence in the predictive power of such place-based sociohydrologic models remains low. The generalizability of SH models therefore requires major advances in incorporating more realistic relationships, underpinned by appropriate hydrological and social-science data and theories. The latter is a critical input, since human culture - especially values and norms arising from it - influences behavior and the consequences of behaviors. This paper reviews a key social-science theory that links cultural factors to environmental decision-making, assesses how to better incorporate social-science insights to enhance SH models, and raises important questions to be addressed in moving forward. This is done in the context of recent progress in sociohydrological studies and the gaps that remain to be filled. The paper concludes with a discussion of challenges and opportunities in terms of generalization of SH models and the use of available data to allow future prediction and model transfer to ungauged basins.

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This study demonstrates a socio-hydrological model used to examine what future conditions could be like in the Murrumbidgee basin, Australia, arising from change in climate and the economy. The model uses a coupled socio-hydrological dynamical system with endogenous social values and preferences. The dynamical system is represented by a suite of differential equations that can evolve over time. The model exogenous drivers were economic and climatic-based. The model revealed possible future scenarios and the exogenous forcing conditions that led to sustainable basin development. The model revealed that a higher level of diversification in the basin’s economy increases its sustainability and how this is enhanced by the moderate growth of the national economy. This highlights the link between a diversified basin economy and sustainability and how policy-makers and resource managers should focus on measures that diversify a basin’s economy when the national economy is expanding when it is perhaps easiest to implement. @en

Water diversion for environmental purposes threatens many agricultural communities. This paper focuses on the water-agriculture-environment nexus in the Murrumbidgee River Basin, Australia, and attempts to explain how reduced water allocation to agriculture aimed at protecting the environment in turn impacted the wider economy and the community. Predictably reduced water allocation saw declines in agriculture production and employment. Despite this, paradoxically, the basin unemployment rate declined and basin median household income increased. To understand and interpret this, we first analyze available labour, economic and hydrology data, and then develop a simple dynamic model to interpret the observed pattern of basin employment and unemployment. Data analysis revealed the likely causes behind the paradox as (a) out-migration of people from the basin, and (b) absorption of the labour force in the fast growing non-agricultural sectors of the diversified basin economy. The model simulations reinforced this interpretation. Further model simulations under alternative realities of out-migration and sectoral transformation indicated that basins embedded in faster growing national economies, and are more diversified to begin with, are likely to be more conducive to agriculture sector reform (e.g., reduced water allocation) and environmental regeneration. This is a sobering message for other regions experiencing environmental degradation due to extensive agricultural development.

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This study is focused on the water-agriculture-environment nexus as it played out in the Murrumbidgee River Basin, eastern Australia, and how coevolution of society and water management actually transpired. Over 100 years of agricultural development the Murrumbidgee Basin experienced a “pendulum swing” in terms of water allocation, initially exclusively for agriculture production changing over to reallocation back to the environment. In this paper, we hypothesize that in the competition for water between economic livelihood and environmental wellbeing, economic diversification was the key to swinging community sentiment in favor of environmental protection, and triggering policy action that resulted in more water allocation to the environment. To test this hypothesis, we developed a sociohydrology model to link the dynamics of the whole economy (both agriculture and industry composed of manufacturing and services) to the community's sensitivity toward the environment. Changing community sensitivity influenced how water was allocated and governed and how the agricultural sector grew relative to the industrial sector (composed of manufacturing and services sectors). In this way, we show that economic diversification played a key role in influencing the community's values and preferences with respect to the environment and economic growth. Without diversification, model simulations show that the community would not have been sufficiently sensitive and willing enough to act to restore the environment, highlighting the key role of sectoral transformation in achieving the goal of sustainable agricultural development.

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Increasingly the competition for water between food production and the environment threatens the viability of agricultural communities. This paper focused on this water-food-environment nexus in the Murrumbidgee River Basin, Australia, and how it contributed to the evolution of the regional economy and changing demographic patterns. Paradoxically, against expectations, changes in water management favouring the environment coincided with falling unemployment and increase in average regional income, despite a decline in agriculture. To understand this, and to explore how the competition for water played out in the Murrumbidgee Basin, we develop and use a socio-hydrologic model that explicitly considers bi-directional feedbacks between human and water systems. The modelling shows that in response to widespread ecosystem degradation, community sentiment forced new water management policies that favoured ecosystems which inevitably led to reductions in agriculture production. In response, the basin economy reorganized through sectoral transformation to the manufacturing and service sectors, improved agricultural practices, and out-migration of basin residents. The sectoral transformation was facilitated by capital available for investment in manufacturing and service sectors with knock-on impacts on population dynamics and unemployment. Collectively these contributed to a sustainable transformation of the basin economy. The study shows how transformation of the basin economy and demographics mitigated potentially adverse economic outcomes and enabled society to cope with water management decisions that favoured the environment. The dynamics outlined here highlight the adaptive capacity of people and movement of capital in a free economy, supported by appropriate strategies and funding, to cope with water stress.@en