Group on River Basin Economics and Policy Modeling (GRBEPM)

Jose Albiac

April 27, 2021

Hydroeconomic modeling: a useful tool for water management in river basins

Zaragoza Team (Spain)

Meeting: The Ebro River Basin

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The researchers in the Zaragoza team are: Encarna Esteban, Jose Albiac, Daniel Crespo, Safa Baccour and Elena Calvo

In water resources, we study the problems of water scarcity and the problems of water quality degradation from agricultural nonpoint pollution

The research topics deal with agriculture and forestry, evaluating the policies of the primary sector and the impacts on the environment. The research focus on sustainable interventions for the management of land and water resources

The evolution of methodologies

We started working at irrigation district level using crop growth simulation packages

We used mathematical optimization, at first with linear programing and later on with dynamic programing

We worked in the Monegros irrigation district, where biophysical information was available

We used biophysical information to represent yield and pollution functions

Then we moved to analyze water allocation at large spatial levels, working in the large interbasin transfer from the Ebro Basin to the Jucar and the Segura basins

We analyzed 400.000 ha of irrigated cultivation to find out the benefits and costs of the interbasin water transfer (1000 Mm³) with costs around 6 billion Euros

We have worked also on groundwater in La Mancha aquifers in Spain, comparing collective action in Eastern La Mancha with complete mismanagement in Western La Mancha

Eastern La Mancha

Western La Mancha

Then, Taher Kahil started working in hydroeconomic modeling with the help of Ariel Dinar and Frank Ward in the Jucar Basin

The hydroeconomic model included the hydrology of the basin, the economic activities, and the environment

Streamflows in the Jucar River along La Mancha aquifer

An important issue is the assessment of the impact that the Easter La Mancha aquifer is having on water scarcity in the basin, and the water policies for more sustainable water management

This is the Modeling Framework: the hydrologic, economic and environmental components and the linkages among them

Now, we are working in the Ebro Basin

Irrigation districts and main cities

Population 3.2 million inhabitants, Economic activities: Services (63% GDP), Industries (33%), Agriculture (4%)

Water resources in the Ebro Basin (Mm³)

2) the allocation of water between economic activities and aquatic ecosystems. Environmental benefits are estimated from the response of aquatic ecosystems to stream flows in river sections. Decisions on withdrawals and environmental flows maximize social benefits, the sum of economic and environmental benefits (Daniel)

1) the environmental flows at the mouth of the basin sustaining the Ebro Delta, and the conflict between upstream and downstream states.

The downstream state (Cataluña) is asking for very large flows that compromise economic activities in upstream states (Daniel)

We have addressed three issues in the Ebro Basin:

Ebro River flow and minimum environmental flow at the mouth (Mm³)

3) We assess water scarcity and agricultural nonpoint pollution in the basin. Hydrological, economic and pollution features capture spatial and sectoral interactions.

Mitigation and adaptation policies under droughts are evaluated, along with water quantity and water quality tradeoffs (Safa)

1) Environmental Flows at the Ebro Mouth

Benefits from current (3,000) and ACA 2015 (5,870) environmental flows, under severe drought (10⁶ €)

Drought losses increase heavily when minimum environmental flows at mouth are doubled (from 3,000 to 5,870 Mm³)

Environmental Flows at the Ebro Mouth

But further expanding minimum environmental flows up to 7,150 Mm³ is unfeasible

Environmental benefits in river sections depend on the response of aquatic ecosystems to stream flows

The function characterizing ecosystem status explains Weighted Usable Area (WUA) by stream flow (X) in river reach i :

Environmental benefits of policies under normal and drought conditions

2) Water Allocation between Economic Activities and Aquatic Ecosystems

“Environmental institutional cooperation” yields the higher environmental flows, although “Environmental water markets” achieve slightly higher social benefits

Water Allocation between Economic Activities and Aquatic Ecosystems

Stream flows along the Ebro main stem during drought, by policy

In this study, we assess water scarcity and pollution abatement policies in the Ebro

3) Water Scarcity and Agricultural Nonpoint Pollution

GHGs emissions in the baseline (Livestock 7 MtCO₂eq; Crops 1 MtCO₂eq)

Mitigation and adaptation policies are evaluated to address GHGs emissions to the atmosphere and nitrate loads into water courses

We look also at the tradeoffs between water quantity and water quality in the basin.

Water Scarcity and Agricultural Nonpoint Pollution

Nitrate loads in the baseline

At the source:

Livestock 204,000 tNO₃-N

Crops 32,000 tNO₃-N

Entering water bodies:

Livestock 81,000 tNO₃-N

Crops 13,000 tNO₃-N

Water Scarcity and Agricultural Nonpoint Pollution

Nitrogen applied, leached, and excreted for each policy under normal and drought conditions

Water Scarcity and Agricultural Nonpoint Pollution

GHG emissions for each policy under normal and drought conditions

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Zaragoza Research Team “ECONATURA”

Universidad de Zaragoza-CITA

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Research financed with projects INIA, European Union, Ministry of Science and Innovation, La Caixa-Gobierno de Aragón, and MAPFRE Foundation

Selected references (Available in ResearchGate):

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Crespo D., J. Albiac, A. Dinar, E. Esteban, T. Kahil. 2021. Integrating ecosystem benefits in hydroeconomic modeling for sustainable water allocation. Preparing for publication.

Baccour, S., J. Albiac, T. Kahil, E. Esteban, D. Crespo, A. Dinar. 2021. Hydroeconomic modeling for assessing water scarcity and pollution abatement policies in the Ebro River Basin, Spain. Under review.

Crespo D., J. Albiac, T. Kahil, E. Esteban, S. Baccour. 2019. Tradeoffs between Water Uses and Environmental Flows: A Hydroeconomic Analysis in the Ebro Basin. Water Resources Management 33: 2301-2317

Kahil M., A. Dinar y J. Albiac. 2015. Modeling water scarcity and droughts for policy adaptation to climate change in arid and semiarid regions. Journal of Hydrology 522: 95-109.

Esteban E., J. Albiac. 2011. Groundwater and ecosystems damages: Questioning the Gisser-Sánchez effect. Ecological Economics 70: 2062-2068.

Albiac J. 2009. Nutrient Imbalances: Pollution Remains. Science 326 (5953): 665 (Letter).

Albiac J., M. Hanemann, J. Calatrava, J. Uche, J. Tapia. 2006. The rise and fall of the Ebro water transfer. Natural Resources Journal 46 (3): 727-757.

Martínez Y. , J. Albiac. 2004. Agricultural pollution control under Spanish and European environmental policies. Water Resources Research 40 (10).