Dynamic Feedback Coupling of Continuous Hydrologic and Socio-Economic Model Components of the Upper Thames River Basin

The main contribution of this work consists of formulating a novel simulation framework used in analysis of climate change impact assessment. The model developed consists of a continuous hydrologic component coupled (via feedback) to a socioeconomic component developed using system dynamics. The hydrologic component of the model responds to changes in socio-economic conditions (such as changing economic, demographic and land use patterns), while socio-economic conditions are continually influenced by hydrologic quantities (such as available ground water recharge, flow and precipitation). As the two components are connected via feedback, each dynamically influences, and is influenced by, the other thereby mimicking such interactions in the real world. The combined model represents a comprehensive integrated water resources management tool developed to test climatic impact and change of both hydrologic and socio-economic conditions in the area. The model is developed for the Upper Thames River basin, located in southwestern Ontario, Canada. The study area encompasses a number of growing urban and rural communities, with the largest community being the City of London. The entire basin is approximately 3,500 km2, with an approximate population of 420,000 (of which 350,000 live in the City of London). Agricultural land occupies approximately 80% of basin’s land area, while forest cover and urban land take up about 10% each. Hydrology of the basin is quantified with a continuous hydrologic model component, and incudes detailed modules describing snow accumulation and melt; losses; transformation of surface excess to river runoff; representation of baseflow; as well hydrologic river routing methods. The socio-economic characteristics are expressed with a component describing dynamics of urban and rural population; business and housing, as well as detailed land and water use patterns. The overall (or combined) model couples two components, and is thus capable of testing a wide range of socioeconomic policies and management strategies (like changes in demographics, housing, jobs, land and water use practices), as well as able to produce detailed hydrologic output (like frequency of floods/drought, timing and regularity of flows) typically used for impact analysis and/or engineering design. Simulation of the model is performed for three different climate scenarios (no change, increased precipitation, and increased temperature) obtained from an external weather generator (a tool used to simulate alternate regional climate characteristics based on historical information as well as latest knowledge of global climate models). The climate scenarios are coupled with a range of socio-economic scenarios where different management strategies are explored (such as proceeding with the belief that regional water resources are infinite, implementing a strict water conservation policy, a combination of water conservation with limiting land development, as well as implementing a switch from ground to surface water use basin wide). The main findings revealed by simulation of different scenarios include the following: (i) climate change has the potential to significantly alter flooding characteristics of the region by increasing risk levels (and its corresponding frequency of occurrence) of extreme conditions; (ii) frequency of extremes of drought conditions are likely to remain at their current levels and, (iii) the most significant regional socio-economic factor is availability of water, shown as a limiting agent to growth of population and regional economy. Recommendations are suggested to area’s water resources professionals that urge them to consider revising existing management guidelines in light of knowledge of altered hydrologic and socio-economic conditions in the basin as a result of climatic change.https://ir.lib.uwo.ca/wrrr/1016/thumbnail.jp

Inverse Flood Risk Modelling of The Upper Thames River Basin

This report aims to present an alternate approach to climate change impact mod- elling of water resources. The focus of the project is on the analysis of existing wa- ter resources management guidelines specifically targeting critical hydrologic events (extreme floods in this case). The critical hydrologic events are converted to their corresponding meteorologic conditions via use of an event based hydrologic model. The local climatic signal is generated by use of a non-parametric weather generator linked to outputs from a global climate model for three climate scenarios, and their corresponding frequency curves generated. Then, a critical hydrologic event of inter- est is selected, its corresponding meteorological condition obtained, and its frequency of occurrence (one for each climate scenario) determined. A scenario selected specifically to study the problem of flooding in the basin showed more frequent occurrence of flooding for nearly all magnitudes of floods. An- other scenario, selected for studying droughts depicts a lesser tendency of extreme flooding events. Therefore, ranges of estimates of changes of frequency of occurrence of critical hydrologic events are obtained in response to changing climatic conditions. Based on these estimates, recommendations for changing current basin management guidelines are provided. They are categorized into three distinct categories: (i) regula- tory (where a review of rules, regulations and operation of current flood management infrastructure are suggested); (ii) budgetary (where investment in new infrastructure, as well as increased maintenance costs of present and future infrastructure, can lead to a need of having higher operating budgets); and (iii) engineering (recommending a review of current design standards of critical infrastructure).https://ir.lib.uwo.ca/wrrr/1014/thumbnail.jp

Development of Rainfall Intensity duration Frequency Curves for the City of London under the Changing Climate

The main focus of this study is the analysis of short duration high intensity rainfall for London, Ontario under the conditions of the changed climate. Predicted future climate change impacts for Southwestern Ontario include higher temperatures and increases in precipitation, leading to an intensification of the hydrologic cycle. One of the expected consequences of change is an increase in the magnitude and frequency of extreme events (e.g. high intensity rainfall, flash flooding, severe droughts, etc.). Changes in extreme events are of particular importance to the design, operation and maintenance of municipal water management infrastructure. Municipal water management infrastructure (sewers, storm water management ponds or detention basins, street curbs and gutters, catchbasins, swales, etc) designs are typically based on the use of local rainfall Intensity Duration Frequency (IDF) curves. IDF curves are developed using historical rainfall time series data. Annual extreme rainfall is fitted to a theoretical probability distribution from which rainfall intensities, corresponding to particular durations, are obtained. In the use of this procedure an assumption is made that historic extremes can be used to characterize extremes of the future (i.e., the historic record is assumed to be stationary). This assumption is not valid under changing climatic conditions that may bring shifts in the magnitude and frequency of extreme rainfall. Such shifts in extreme rainfall at the local level demand new regulations for water infrastructure management as well as changes in design practices. The objective of this report is to assess the change in IDF curves for use by the City of London under changing climatic conditions. The methodology implemented to assess changes in rainfall magnitude resulting from climate change includes the following components: (a) Development and use of a daily weather generator model for synthetic generation of rainfall under current and future climates; (b) Disaggregation of daily rainfall into hourly; (c) Statistical analysis of rainfall of various durations, and development of IDF curves under changed climatic conditions; (d) Comparative analysis of IDF curves; and (e) Recommendation for possible modification of municipal infrastructure design standards. The two IDF curves currently used by the City of London (i.e., MacLauren IDF curve for design of conveyance systems, and Atmospheric Environment Service IDF curve for storm water management facilities) could have not be reproduced in this research using the data currently available from Meteorological Service of Canada. The IDF curves in use by the City are based on data sets that are no longer available. In addition, methods used by either MacLauren or Meteorological Service of Canada to estimate rainfall quantiles for durations shorter than one hour are not available. Therefore, comparing the IDF curves generated in this research to those currently used by the City of London is not appropriate. More confidence is placed in the relative difference between the three scenarios generated in this research: simulated historic climate (no change), and wet and dry climates (change guided by outputs of global circulation model outputs). The results of simulations in this research indicate that rainfall magnitude (as well as intensity) will be different than historically observed. The climate change scenario recommended for use in the evaluation of storm water management design standards (i.e., the wet scenario) reveals a significant increase in rainfall magnitude (and intensity) for a range of durations and return periods. This increase has major implications on the ways in which current (and future) municipal water management infrastructure is designed, operated, and maintained. The main recommendation from this work is that the design standards and guidelines currently employed by the City of London be reviewed and/or revised in light of the information presented in this report.https://ir.lib.uwo.ca/wrrr/1020/thumbnail.jp

Generation of Synthetic Design Storms for the Upper Thames River Basin

The purpose of this report is to summarize methods available in the literature that synthetically generate rainfall hyetographs (plots of rainfall intensity vs. time). The outputs of selected methods are to be used as inputs to a hydrological model of the Upper Thames River basin, to be used for determination of hydrologic risks and extremes.https://ir.lib.uwo.ca/wrrr/1011/thumbnail.jp

Inverse Drought Risk Modelling of the Upper Thames River Basin

This report aims to present an alternate approach to climate change impact mod- elling of water resources. The focus of the project is on the analysis of existing water resources management guidelines specifically targeting critical hydrologic events (ex- treme droughts in this case). The critical hydrologic events are converted to their corresponding meteorologic conditions via use of an appropriate hydrologic model (continuous based hydrologic model for drought analysis). The local climatic signal is generated by use of a non-parametric weather generator linked to outputs from a global circulation model for three climate scenarios, and their corresponding fre- quency curves generated. Then, a critical hydrologic event of interest is selected, its corresponding meteorological condition obtained, and its frequency of occurrence for each climate scenario determined. It is noted that all climate change scenarios showed less frequent occurrence of extreme droughts. However, potentially severe droughts are still possible (with a chance of 1 in 10 any given year, sometime less) in the basin; this coupled with the fact that drought damage assessments are non existent in the basin suggests that new or improved drought management guidelines should be investigated. Based on the analysis presented, recommendations are made for future work to in- clude: (i) drought impact studies (where impacts to agriculture, recreation, wetlands, reservoir operation, ground water withdrawal and streamflow quality are assessed); (ii) definition of local drought triggers (including guidelines on subwatershed scale, as well as monitoring how drought triggers change over time); (iii) water quality man- agement (setting in place practises that enhance water quality over short and long term); (iv) education programs (to bring up to date knowledge in science to all who stand to be adversely impacted by drought).https://ir.lib.uwo.ca/wrrr/1015/thumbnail.jp

State forecasting and operational planning for distribution network energy management systems

This paper describes the application of advanced metering infrastructure data for developing energy forecasting and operational planning services in distribution networks with significant distributed energy resources. This paper describes development of three services designed for use in distribution network energy management systems. These are comprised of a demand forecasting service, an approach for constraint management in distribution networks, and a service for forecasting voltage profiles in the low voltage network. These services could be applied as part of an advanced distribution network management system in order to improve situational awareness and provide early warning of potential network issues. The methodology and its applicability is demonstrated using recorded supervisory control and data acquisition and smart meter data from an existing medium voltage distribution network

Residential demand management using individualised demand aware price policies

This paper presents a novel approach to demand side management (DSM), using an “individualized” price policy, where each end user receives a separate electricity pricing scheme designed to incentivize demand management in order to optimally manage flexible demands. These pricing schemes have the objective of reducing the peaks in overall system demand in such a way that the average electricity price each individual user receives is non-discriminatory. It is shown in this paper that this approach has a number of advantages and benefits compared to traditional DSM approaches. The “demand aware price policy” approach outlined in this paper exploits the knowledge, or demand-awareness, obtained from advanced metering infrastructure. The presented analysis includes a detailed case study of an existing European distribution network where DSM trial data was available from the residential end-users

An optimal day-ahead load scheduling approach based on the flexibility of aggregate demands

The increasing trends of energy demand and renewable integration call for new and advanced approaches to energy management and energy balancing in power networks. Utilities and network system operators require more assistance and flexibility shown from consumers in order to manage their power plants and network resources. Demand response techniques allow customers to participate and contribute to the system balancing and improve power quality. Traditionally, only energy-intensive industrial users and large customers actively participated in demand response programs by intentionally modifying their consumption patterns. In contrast, small consumers were not considered in these programs due to their low individual impact on power networks, grid infrastructure and energy balancing. This paper studies the flexibility of aggregated demands of buildings with different characteristics such as shopping malls, offices, hotels and dwellings. By using the aggregated demand profile and the market price predictions, an aggregator participates directly in the day-ahead market to determine the load scheduling that maximizes its economic benefits. The optimization problem takes into account constraints on the demand imposed by the individual customers related to the building occupant comfort. A case study representing a small geographic area was used to assess the performance of the proposed method. The obtained results emphasize the potential of demand aggregation of different customers in order to increase flexibility and, consequently, aggregator profits in the day-ahead market