Joaquín Andreu

AQUATOOL, A GENERALIZED DECISION-SUPPORT SYSTEM FOR WATER-RESOURCES PLANNING AND OPERATIONAL MANAGEMENT

Abstract This paper describes a generic decision-support system (DSS) which was originally designed for the planning stage of dicision-making associated with complex river basins. Subsequently, it was expanded to incorporate modules relating to the operational stage of decision-making. Computer-assisted design modules allow any complex water-resource system to be represented in graphical form, giving access to geographically referenced databases and knowledge bases. The modelling capability includes basin simulation and optimization modules, an aquifer flow modelling module and two modules for risk assessment. The Segura and Tagus river basins have been used as case studies in the development and validation phases. The value of this DSS is demonstrated by the fact that both River Basin Agencies currently use a version for the efficient management of their water resources.

GIS-based models for water quantity and quality assessment in the Júcar River Basin, Spain, including climate change effects.

This paper describes two different GIS models - one stationary (GeoImpress) and the other non-stationary (Patrical) - that assess water quantity and quality in the Júcar River Basin District, a large river basin district (43,000km(2)) located in Spain. It aims to analyze the status of surface water (SW) and groundwater (GW) bodies in relation to the European Water Framework Directive (WFD) and to support measures to achieve the WFD objectives. The non-stationary model is used for quantitative analysis of water resources, including long-term water resource assessment; estimation of available GW resources; and evaluation of climate change impact on water resources. The main results obtained are the following: recent water resources have been reduced by approximately 18% compared to the reference period 1961-1990; the GW environmental volume required to accomplish the WFD objectives is approximately 30% of the GW annual resources; and the climate change impact on water resources for the short-term (2010-2040), based on a dynamic downscaling A1B scenario, implies a reduction in water resources by approximately 19% compared to 1990-2000 and a reduction of approximately 40-50% for the long-term (2070-2100), based on dynamic downscaling A2 and B2 scenarios. The model also assesses the impact of various fertilizer application scenarios on the status of future GW quality (nitrate) and if these future statuses will meet the WFD requirements. The stationary model generates data on the actual and future chemical status of SW bodies in the river basin according to the modeled scenarios and reflects the implementation of different types of measures to accomplish the Urban Waste Water Treatment Directive and the WFD. Finally, the selection and prioritization of additional measures to accomplish the WFD are based on cost-effectiveness analysis.

A decision support system for water quality issues in the Manzanares River (Madrid, Spain).

The Manzanares River, located in Madrid (Spain), is the main water supplier of a highly populated region, and it also receives wastewater from the same area. The effluents of eight Waste Water Treatment Plants (WWTPs) downstream of the river, which represent 90% of the flow in the middle and lower parts of the river, are the primary sources of water pollution. Although the situation has improved slightly in the last two years, the water in the river is highly polluted, making it uninhabitable for aquatic life. Water quality modelling is typically used to assess the effect of treatment improvements in water bodies. In this work, the GESCAL module of the Aquatool Decision Support System Shell was used to simulate water quality in the Manzanares River. GESCAL is appropriate for modelling in an integrated way water quality for whole water resources systems, including reservoirs and rivers. A model was built that simulates conductivity, phosphorous, carbonaceous organic matter, dissolved oxygen, organic nitrogen, ammonia, and nitrates. The period from October 2006 to September 2008 was selected for calibration due to the many treatment modifications that occurred during this time. An earlier and longer period, from October 2000 to September 2006, was used for validation. In addition, a daily model was used to analyse the robustness of the GESCAL model. Once the GESCAL model was validated, different scenarios were considered and simulated. First, different combinations of nutrient elimination among the different WWTPs were simulated, leading to the conclusion that investments have to focus on three of the proposed WWTPs. Moreover, these treatments will not be sufficient to maintain fish habitat conditions at all times. Additional measures, such as the increment of the flow in the river or oxygen injection, were simulated. Incrementing the flow of the Manzanares River has been shown to be an efficient means of increasing water quality, but this implies an increment in the risk of water scarcity situations in the Madrid water supply system.

Design of Efficient Water Pricing Policies Integrating Basinwide Resource Opportunity Costs

AbstractBy ignoring the opportunity cost of water use, water is undervalued, which can lead to significant errors in investments and water allocation decisions. The marginal resource opportunity cost (MROC) varies in time and space, as resource availability, demands, and users’ WTP vary. This spatial and temporal variability can only be captured by basinwide hydro-economic models integrating water demands and environmental requirements, resources, infrastructure, and operational and institutional restrictions. This paper presents a method for the simulation of water pricing policies linked to water availability, and the design of efficient pricing policies that incorporate the basinwide marginal value of water. Two approaches were applied: priority-based simulation and economic optimization. The improvement in economic efficiency was assessed by comparing the results from simulation of the current system operation and the pricing schedule. The difference between the benefits for the simulated current mana...

A Model for Solving the Optimal Water Allocation Problem in River Basins with Network Flow Programming When Introducing Non-Linearities

The allocation of water resources between different users is a traditional problem in many river basins. The objective is to obtain the optimal resource distribution and the associated circulating flows through the system. Network flow programming is a common technique for solving this problem. This optimisation procedure has been used many times for developing applications for concrete water systems, as well as for developing complete decision support systems. As long as many aspects of a river basin are not purely linear, the study of non-linearities will also be of great importance in water resources systems optimisation. This paper presents a generalised model for solving the optimal allocation of water resources in schemes where the objectives are minimising the demand deficits, complying with the required flows in the river and storing water in reservoirs. Evaporation from reservoirs and returns from demands are considered, and an iterative methodology is followed to solve these two non-network constraints. The model was applied to the Duero River basin (Spain). Three different network flow algorithms (Out-of-Kilter, RELAX-IV and NETFLO) were used to solve the allocation problem. Certain convergence issues were detected during the iterative process. There is a need to relate the data from the studied systems with the convergence criterion to be able to find the convergence criterion which yields the best results possible without requiring a long calculation time.

Improving value transfer through socio-economic adjustments in a multicountry choice experiment of water conservation alternatives

This study tests the transferability of the nonmarket values of water conservation for domestic and environmental purposes across three south European countries and Australia applying a common choice experiment design. Different approaches are followed to test the transferability of the estimated values, aiming to minimise transfer errors for use in policy analysis, comparing both single- and multicountry transfers, with and without socio-economic adjustments. Within Europe, significant differences are found between implicit prices for environmental water use, but not for domestic water use. In the Australian case study, alleviating restrictions on domestic water use has no significant value. Pooling the three European samples improves the transferability of the environmental flow values between Europe and Australia. Results show that a reduction in transfer error is achieved when controlling for unobserved and observed preference heterogeneity in the single- and multicountry transfers, providing additional support for the superiority of socio-economic adjustment procedures in value transfer.

Managing water quality under drought conditions in the Llobregat River Basin

The primary effects of droughts on river basins include both depleted quantity and quality of the available water resources, which can render water resources useless for human needs and simultaneously damage the environment. Isolated water quality analyses limit the action measures that can be proposed. Thus, an integrated evaluation of water management and quality is warranted. In this study, a methodology consisting of two coordinated models is used to combine aspects of water resource allocation and water quality assessment. Water management addresses water allocation issues by considering the storage, transport and consumption elements. Moreover, the water quality model generates time series of concentrations for several pollutants according to the water quality of the runoff and the demand discharges. These two modules are part of the AQUATOOL decision support system shell for water resource management. This tool facilitates the analysis of the effects of water management and quality alternatives and scenarios on the relevant variables in a river basin. This paper illustrates the development of an integrated model for the Llobregat River Basin. The analysis examines the drought from 2004 to 2008, which is an example of a period when the water system was quantitative and qualitatively stressed. The performed simulations encompass a wide variety of water management and water quality measures; the results provide data for making informed decisions. Moreover, the results demonstrated the importance of combining these measures depending on the evolution of a drought event and the state of the water resources system.

Integrating water management, habitat modelling and water quality at the basin scale and environmental flow assessment: case study of the Tormes River, Spain

Abstract Multidisciplinary models are useful for integrating different disciplines when addressing water planning and management problems. We combine water resources management, water quality and habitat analysis tools that were developed with the decision support system AQUATOOL at the basin scale. The water management model solves the allocation problem through network flow optimization and considers the environmental flows in some river stretches. Once volumes and flows are estimated, the water quality model is applied. Furthermore, the flows are evaluated from an ecological perspective using time series of aquatic species habitat indicators. This approach was applied in the Tormes River Water System, where agricultural demands jeopardize the environmental needs of the river ecosystem. Additionally, water quality problems in the lower part of the river result from wastewater loading and agricultural pollution. Our methodological framework can be used to define water management rules that maintain water supply, aquatic ecosystem and legal standards of water quality. The integration of ecological and water management criteria in a software platform with objective criteria and heuristic optimization procedures allows realistic assessment and application of environmental flows to be made. Here, we improve the general methodological framework by assessing the hydrological alteration of selected environmental flow regime scenarios. Editor D. Koutsoyiannis; Guest editor M. Acreman Citation Paredes-Arquiola, J., Solera, A., Martinez-Capel, F., Momblanch, A., and Andreu, J., 2014. Integrating water management, habitat modelling and water quality at the basin scale and environmental flow assessment: case study of the Tormes River, Spain. Hydrological Sciences Journal, 59 (3–4), 878–889.

Methodology for Drought Risk Assessment in Within-year Regulated Reservoir Systems. Application to the Orbigo River System (Spain)

Drought occurrence and its related impacts are a major concern in many river basins throughout the world. In the last years, drought management procedures have moved from a crisis approach towards a more sensitive preparedness approach. Drought plans development has arisen as an effective way of providing measures and actions to manage drought situations. However, due to each river basin has different operation characteristics, drought management requires a different approach in order to be efficient. Decision support tools are a great ally of water managers, especially in situations of high water stress and hydrologic uncertainty, allowing them to in-deep analyze the system and finding the best measures to minimize the risk of a system failure. This paper studies the difficulties of only using an indicator system based in current and past data to assess the drought risk in within-year regulated reservoir systems. It proposes the complementary use of a general risk assessment methodology to anticipate the future probable status of the system and defining the current drought scenario. It shows how the complementary use of a monitoring system and a risk assessment decision support system may improve the drought detection process allowing water managers optimizing the selection of mitigation measures and minimizing the probability of overreaction during a drought situation.

Drought Planning and Management in the Júcar River Basin, Spain

In the Jucar River Basin, water scarcity and hydrological variability produce frequent and long hydrological droughts. Preparation for droughts is achieved through (a) integrated river basin planning, including proactive measures that minimize the risk of operative droughts (i.e., failure of the system to provide water services); (b) special drought plans, including continuous monitoring of drought indexes in order to detect the risk in medium- to short-term management, and sets of proactive and reactive measures for different scenarios (i.e., normal, pre-alert, alert, and emergency); and (c) participatory drought management by means of a special drought committee, to mitigate the impact of droughts and find suitable compromise solutions to provide an equilibrium between economic sectors needs and environmental protection. We will illustrate how these three processes were applied in the recent 2005/2008 drought, and highlight the importance of up-to-date integrative decision support systems in enhancing and facilitating our ability to address drought.