scholarly journals One-way coupling of an integrated assessment model and a water resources model: evaluation and implications of future changes over the US Midwest

2013 ◽  
Vol 10 (5) ◽  
pp. 6359-6406 ◽  
Author(s):  
N. Voisin ◽  
L. Liu ◽  
M. Hejazi ◽  
T. Tesfa ◽  
H. Li ◽  
...  

Abstract. An integrated model is being developed to advance our understanding of the interactions between human activities, terrestrial system and water cycle, and to evaluate how system interactions will be affected by a changing climate at the regional scale. As a first step towards that goal, a global integrated assessment model including a water-demand model is coupled offline with a land surface hydrology – routing – water resources management model. In this study, a spatial and temporal disaggregation approach is developed to project the annual regional water demand simulations into a daily time step and subbasin representation. The model demonstrated reasonable ability to represent the historical flow regulation and water supply over the Midwest (Missouri, Upper Mississippi, and Ohio). Implications for future flow regulation, water supply, and supply deficit are investigated using a climate change projection with the B1 emission scenario, which affects both natural flow and water demand. Over the Midwest, changes in flow regulation are mostly driven by the change in natural flow due to the limited storage capacity over the Ohio and Upper Mississippi River basins. The changes in flow and demand have a combined effect on the Missouri summer regulated flow. The supply deficit seems to be driven by the change in flow over the region. Spatial analysis demonstrates the relationship between the supply deficit and the change in demand over urban areas not along a main river or with limited storage, and over areas upstream of groundwater dependent fields, which therefore have an overestimated surface water demand.

2013 ◽  
Vol 17 (11) ◽  
pp. 4555-4575 ◽  
Author(s):  
N. Voisin ◽  
L. Liu ◽  
M. Hejazi ◽  
T. Tesfa ◽  
H. Li ◽  
...  

Abstract. An integrated model is being developed to advance our understanding of the interactions between human activities, terrestrial system and water cycle, and to evaluate how system interactions will be affected by a changing climate at the regional scale. As a first step towards that goal, a global integrated assessment model, which includes a water-demand model driven by socioeconomics at regional and global scales, is coupled in a one-way fashion with a land surface hydrology–routing–water resources management model. To reconcile the scale differences between the models, a spatial and temporal disaggregation approach is developed to downscale the annual regional water demand simulations into a daily time step and subbasin representation. The model demonstrates reasonable ability to represent the historical flow regulation and water supply over the US Midwest (Missouri, Upper Mississippi, and Ohio river basins). Implications for future flow regulation, water supply, and supply deficit are investigated using climate change projections with the B1 and A2 emission scenarios, which affect both natural flow and water demand. Although natural flow is projected to increase under climate change in both the B1 and A2 scenarios, there is larger uncertainty in the changes of the regulated flow. Over the Ohio and Upper Mississippi river basins, changes in flow regulation are driven by the change in natural flow due to the limited storage capacity. However, both changes in flow and demand have effects on the Missouri River Basin summer regulated flow. Changes in demand are driven by socioeconomic factors, energy and food demands, global markets and prices with rainfed crop demand handled directly by the land surface modeling component. Even though most of the changes in supply deficit (unmet demand) and the actual supply (met demand) are driven primarily by the change in natural flow over the entire region, the integrated framework shows that supply deficit over the Missouri River Basin sees an increasing sensitivity to changes in demand in future periods. It further shows that the supply deficit is six times as sensitive as the actual supply to changes in flow and demand. A spatial analysis of the supply deficit demonstrates vulnerabilities of urban areas located along mainstream with limited storage.


2021 ◽  
Vol 167 (3-4) ◽  
Author(s):  
Camilla C. N. de Oliveira ◽  
Gerd Angelkorte ◽  
Pedro R. R. Rochedo ◽  
Alexandre Szklo

2017 ◽  
Author(s):  
Abigail C. Snyder ◽  
Robert P. Link ◽  
Katherine V. Calvin

Abstract. Hindcasting experiments (conducting a model forecast for a time period in which observational data is available) are rarely undertaken in the Integrated Assessment Model (IAM) community. When they are undertaken, the results are often evaluated using global aggregates or otherwise highly aggregated skill scores that mask deficiencies. We select a set of deviation based measures that can be applied at different spatial scales (regional versus global) to make evaluating the large number of variable-region combinations in IAMs more tractable. We also identify performance benchmarks for these measures, based on the statistics of the observational dataset, that allow a model to be evaluated in absolute terms rather than relative to the performance of other models at similar tasks. This is key in the integrated assessment community, where there often are not multiple models conducting hindcast experiments to allow for model intercomparison. The performance benchmarks serve a second purpose, providing information about the reasons a model may perform poorly on a given measure and therefore identifying opportunities for improvement. As a case study, the measures are applied to the results of a past hindcast experiment focusing on land allocation in the Global Change Assessment Model (GCAM) version 3.0. We find quantitative evidence that global aggregates alone are not sufficient for evaluating IAMs, such as GCAM, that require global supply to equal global demand at each time period. Additionally, the deviation measures examined in this work successfully identity parametric and structural changes that may improve land allocation decisions in GCAM. Future work will involve implementing the suggested improvements to the GCAM land allocation system identified by the measures in this work, using the measures to quantify performance improvement due to these changes, and, ideally, applying these measures to other sectors of GCAM and other land allocation models.


2014 ◽  
Vol 9 (4) ◽  
pp. 509-518
Author(s):  
R. Shahsavan ◽  
M. Shourian

Water storage using dams is a perfect solution for agricultural, industrial, drinking water supply, flood control, hydroelectric power generation, and other purposes. Integrated management of water resources involves the development, management, protection, regulation and beneficial use of surface- and ground- water resources. The reliability of water supply reservoirs depends on several factors, e.g. the physical characteristics of the reservoir, the time series of river discharge, climatic conditions, the amount of demand, and the method of operation. If a portion of a dam's volume is kept empty for flood control, the confidence values of taking the bottom water demand will be reduced. In this paper, a yield-storage model developed in a MATLAB software environment is used to determine the optimal capacity of Darband dam in northeast Iran (the study phase). The reservoir's performance with respect to demand downstream, e.g. from industry and agriculture, and for potable use, was studied, and the results compared for scenarios in flood control volume change conditions. The results show that, for a capacity of 80 Mm3, the reliability values for meeting agricultural, environmental, and potable water demand are estimated at 0.922, 0.927, and 0.942, respectively. If the reservoir's capacity is changed from 80 to 350 Mm3, the reliability values increase by only about 7%.


2005 ◽  
Vol 32 (1) ◽  
pp. 159-163 ◽  
Author(s):  
Duan Wei

Beijing is located in a semiarid region, and water shortage is a common problem in the city. Along with the rapid increase in water demand, due to fast socioeconomic development and an increase in population, a shortage of water resources and a deterioration of the water environment have become obstacles to sustainable socioeconomic development in Beijing. In the long run, sustainable water resources management, water conservation, and completion of the south to north water diversion project will solve the problem. This paper introduces the water resources situation in Beijing; analyzes future water demand; and discusses the actions of water saving, nontraditional water resources exploitation, wetland construction, and water environment protection. The paper also explains the importance of the south to north water diversion project and the general layout of the water supply strategy, water distribution system, and methods to efficiently use the diverted water in Beijing.Key words: water resources, water supply, water saving, water recycling, water diversion.


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