Roobavannan, M, Van Emmerik, THM, Elshafei, Y, Kandasamy, J, Sanderson, MR, Vigneswaran, S, Pande, S & Sivapalan, M 2018, 'Norms and values in sociohydrological models', Hydrology and Earth System Sciences, vol. 22, no. 2, pp. 1337-1349.View/Download from: UTS OPUS or Publisher's site
© Author(s) 2018. 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.
Roobavannan, M, Kandasamy, J, Pande, S, Vigneswaran, S & Sivapalan, M 2017, 'Allocating Environmental Water and Impact on Basin Unemployment: Role of A Diversified Economy', Ecological Economics, vol. 136, pp. 178-188.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier B.V. Water diversion for environmental pu rposes 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.
Roobavannan, M, Kandasamy, J, Pande, S, Vigneswaran, S & Sivapalan, M 2017, 'Role of Sectoral Transformation in the Evolution of Water Management Norms in Agricultural Catchments: A Sociohydrologic Modeling Analysis', Water Resources Research, vol. 53, no. 10, pp. 8344-8365.View/Download from: UTS OPUS or Publisher's site
© 2017. American Geophysical Union. All Rights Reserved. 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.
Levy, MC, Garcia, M, Blair, P, Chen, X, Gomes, SL, Gower, DB, Grames, J, Kuil, L, Liu, Y, Marston, L, Mccord, PF, Roobavannan, M & Zeng, R 2016, 'Wicked but worth it: Student perspectives on socio-hydrology', Hydrological Processes.View/Download from: Publisher's site
Yoshikawa, S, Yanagawa, A, Iwasaki, Y, Sui, P, Koirala, S, Hirano, K, Khajuria, A, Mahendran, R, Hirabayashi, Y, Yoshimura, C & Kanae, S 2014, 'Illustrating a new global-scale approach to estimating potential reduction in fish species richness due to flow alteration', Hydrology and Earth System Sciences, vol. 18, no. 2, pp. 621-630.View/Download from: Publisher's site
Changes in river discharge due to human activities and climate change would affect the sustainability of freshwater ecosystems. To globally assess how changes in river discharge will affect the future status of freshwater ecosystems, global-scale hydrological simulations need to be connected with a model to estimate the durability of freshwater ecosystems. However, the development of this specific modelling combination for the global scale is still in its infancy. In this study, two statistical methods are introduced to link flow regimes to fish species richness (FSR): one is based on a linear relationship between FSR and mean river discharge (hereafter, FSR-MAD method), and the other is based on a multi-linear relationship between FSR and ecologically relevant flow indices involving several other flow characteristics and mean river discharge (FSR-FLVAR method). The FSR-MAD method has been used previously in global simulation studies. The FSR-FLVAR method is newly introduced here. These statistical methods for estimating FSR were combined with a set of global river discharge simulations to evaluate the potential impact of climate-change-induced flow alterations on FSR changes. Generally, future reductions in FSR with the FSR-FLVAR method are greater and much more scattered than with the FSR-MAD method. In arid regions, both methods indicate reductions in FSR because mean discharge is projected to decrease from past to future, although the magnitude of reductions in FSR is different between the two methods. In contrast, in heavy-snow regions a large reduction in FSR is shown by the FSR-FLVAR method due to increases in the frequency of low and high flows. Although further research is clearly needed to conclude which method is more appropriate, this study demonstrates that the FSR-FLVAR method could produce considerably different results when assessing the global role of flow alterations in changing freshwater ecosystems.©Author(s) 2014. CC Attribution 3.0 License.
Koirala, S, Hirabayashi, Y, Mahendran, R & Kanae, S 2014, 'Global assessment of agreement among streamflow projections using CMIP5 model outputs', Environmental Research Letters, vol. 9, no. 6, pp. 064017-064017.View/Download from: Publisher's site
Hirabayashi, Y, Mahendran, R, Koirala, S, Konoshima, L, Yamazaki, D, Watanabe, S, Kim, H & Kanae, S 2013, 'Global flood risk under climate change', Nature Climate Change, vol. 3, no. 9, pp. 816-821.View/Download from: UTS OPUS or Publisher's site
A warmer climate would increase the risk of floods. So far, only a few studies have projected changes in floods on a global scale. None of these studies relied on multiple climate models. A few global studies have started to estimate the exposure to flooding (population in potential inundation areas) as a proxy of risk, but none of them has estimated it in a warmer future climate. Here we present global flood risk for the end of this century based on the outputs of 11 climate models. A state-of-the-art global river routing model with an inundation scheme was employed to compute river discharge and inundation area. An ensemble of projections under a new high-concentration scenario demonstrates a large increase in flood frequency in Southeast Asia, Peninsular India, eastern Africa and the northern half of the Andes, with small uncertainty in the direction of change. In certain areas of the world, however, flood frequency is projected to decrease. Another larger ensemble of projections under four new concentration scenarios reveals that the global exposure to floods would increase depending on the degree of warming, but interannual variability of the exposure may imply the necessity of adaptation before significant warming. © 2013 Macmillan Publishers Limited. All rights reserved.