Alberto Montanari University of Bologna 1 Advanced Hydrology

Learning Objectives Water Resources Management is about solving problems to secure water for people, based on a sound scientific understanding of hydrologic and hydraulic processes. This includes protection from excess water and from water shortage, as well as providing sufficient water for a sustainable environment. At the end of this class you will: • be aware of water resources issues at local (state), national and global scale, • be able to qualitatively and quantitatively describe the main processes in the hydrologic cycle, and • be able to provide solutions for typical water resources problems found in practice. 2

Program • Introduction: definitions, quantification of the water cycle, practical problems. • Illustration of a case study: the Emilia-Romagna region, Italy. • Assessment of water resources availability: rainfall-runoff modelling. • Assessment of water resources availability: generation of synthetic hydrological variables. • Water resources management: decision theory and decision under uncertainty. • Water resources management: the impact of climate change. 3

Some informations about myself I usually prefer not to indicate fixed receiving hours. I am usually working in my office and therefore I am willing to receive students any time. Appointments can be fixed by email. Email: alberto. montanari@unibo. it Phone: +39 051 2093356 (93356 from internal phones) Web: www. albertomontanari. it Details on the final examination Details on final year projects 4

Suggested text book This textbook covers the first part of the course, which provides and introduction to hydrology. Additional textbooks and notes will be suggested during the following classes. 5

What is Water Resources Engr. /Manag. ? 6 Figure 1. 1. 1 (p. 1) Ingredients of water resources management (from Mays, 1996).

What is Hydrology (1)? From Wikipedia: Hydrology is the study of the movement, distribution, and quality of water throughout the Earth, including the hydrologic cycle, water resources and environmental watershed sustainability. A practitioner of hydrology is a hydrologist, working within the fields of either earth or environmental science, physical geography, geology or civil and environmental engineering. Domains of hydrology include hydrometeorology, surface hydrology, hydrogeology, drainage basin management and water quality, where water plays the central role. Oceanography and meteorology are not included because water is only one of many important aspects. Hydrological research can inform environmental engineering, policy and planning. Water covers 70% of the Earth's surface (from Wikipedia) 7

What hydrologists do? From Usgs. gov: The hydrologist studies the fundamental transport processes to be able to describe the quantity and quality of water as it moves through the cycle (evaporation, precipitation, streamflow, infiltration, ground water flow, and other components). The engineering hydrologist, or water resources engineer, is involved in the planning, analysis, design, construction and operation of projects for the control, utilization, and management of water resources. Water resources problems are also the concern of meteorologists, oceanographers, geologists, chemists, physicists, biologists, economists, political scientists, specialists in applied mathematics and computer science, and engineers in several fields. Hydrologists apply scientific knowledge and mathematical principles to solve water-related problems in society: problems of quantity, quality and availability. They may be concerned with finding water supplies for cities or irrigated farms, or controlling river flooding or soil erosion. Or, they may work in environmental protection: preventing or cleaning up pollution or locating sites for safe disposal of hazardous wastes. Persons trained in hydrology may have a wide variety of job titles. Scientists and engineers in hydrology may be involved in both field investigations and office work. In the field, they may collect basic data, oversee testing of water quality, direct field crews and work with equipment. Many jobs require travel, some abroad. A hydrologist may spend considerable time doing field work in remote and rugged terrain. In the office, hydrologists do many things such as interpreting hydrologic data and performing analyses for determining possible water supplies. The work of hydrologists is as varied as the uses of water and may range from planning multimillion dollar interstate water projects to advising homeowners on drainage problems.

Hydrology has been a subject of investigation and engineering for millennia. For example, about 4000 B. C. the Nile was dammed to improve agricultural productivity of previously barren lands. Mesopotamian towns were protected from flooding with high earthen walls. Aqueducts were built by the Greeks and Ancient Romans, while the History of China shows they built irrigation and flood control works. The ancient Sinhalese used hydrology to build complex irrigation Works in Sri Lanka, also known for invention of the Valve Pit which allowed construction of large reservoirs, anicuts and canals 9 which still function. Ancient Hydrologic History Nile River The longest river in the world (6650 km) Loucks and van Beek, 2006

Ancient Hydrologic History There were many Nilometers in Egypt, but the most important ones were at Elephantine Island. The Nilometer was important as it measured the rise of the floodwaters of the Nile. If the Nile did not rise enough, the land would experience famine conditions. If the Nile rose too high, it would flood and destroy the villages. Every temple in Egypt had a Nilometer because it was a symbol of life. http: //www. bibleplaces. com/aswan. htm 10

Ancient Hydrologic History But hydrology is a young science…. 11 [After Eagleson et al. , 1991, p. 20] 18 Disaster WATER 1 ELL = 1. 1 m NILOMETER READING IN ELLS 20 16 14 12 10 Abundance Security Happiness Suffering Hunger SECURITY

Major Reservoirs of Water 12 [does not add to 100% due to rounding, numbers differ slightly depending on study used]

Water Cycle 13

Water Cycle 14 From Chow et al. , Applied Hydrology, page 6

15 Oki, T. and Kanae, S. 2006. Global hydrological cycles and world water resources. Science, 313, 1068 -1072.

Temporal evolution of natural catastrophes from 1980 to 2012 Source: Munich. RE, Nat. Cat. SERVICE Floods are the first cause of fatalities and economic losses among natural disasters worldwide

Floods Damage survey in St. Genevieve, Missouri, during the 1993 Midwest floods [courtesy of FEMA]. 17 Floods cause extensive damage: “during 1991 -1995, flood related damage totaled more than US$200 billion (not inflation adjusted) globally, representing close to 40% of all economic damage attributed to natural disasters in the period -- (Pielke Jr. and Downton, 2000, citing IFRCRCS, 1997). In the United States, annual flood damage runs in the billions of dollars (Pielke Jr. and Downton, 2000). Improved prediction of floods could reduce these costs substantially, in addition to reducing flood-induced loss of life.

Droughts 18

Water Availability is Decreasing Water availability is decreasing for: • Climate change (need to be very careful); • Overexploitation; • Pollution 19

Water Availability is Decreasing 20

Water Availability is Decreasing 21

By the year 2025 nearly 2 billion people will live in regions or countries with absolute water scarcity, even allowing for high levels of irrigation efficiency. The Future? 22 http: //en. wikipedia. org/wiki/Water_resources Year World Population (billions) 2010 6. 8 2020 7. 6 2030 8. 2 2040 8. 7

Oki, T. and Kanae, S. 2006. Global hydrological cycles and world water resources. Science, 313, 1068 -1072. (Rws > 0. 4) = Water Stress Rws = Water Scarcity Index Rws Total Water Withdrawal – Desalinated Water Renewable Freshwater Resources 23 Rws

Typical Domestic Water Use • 100 -600 L/person/day (high-income countries) • 50 -100 L/person/day (low-income) • 10 -40 L/person/day (water scarce) • Differences in domestic freshwater use: – Piped distribution or carried number/type of appliances and sanitation 24

Human Usage 25

Water Stress • Based on human consumption and linked to population growth • Domestic requirement: – 100 L/person/day = 40 m 3/person/year – 600 L/person/day = 240 m 3/person/year • Associated agricultural, industrial & energy need: – 20 x 40 m 3/person/year = 800 m 3/person/year • Total need: – 840 m 3/person/year – 1040 m 3/person/year 26

Water Stress [m 3/person/year] • • 27 • Water scarcity: <1000 m 3 /person/year – chronic and widespread freshwater problems Water stress: <1700 m 3 /person/year – intermittent, localised shortages of freshwater Relative sufficiency: >1700 m 3 /person/year

The Lake Aral disaster 28

The Lake Aral disaster 29

The Lake Aral disaster 30

The Dublin Principles of 1992 as Guiding Principles for Water Management: 31 In commending this Dublin Statement to the world leaders assembled at the United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro in June 1992, the Conference participants urge all governments to study carefully the specific activities and means of implementation recommended in the Conference Report, and to translate those recommendations into urgent action programmes for water and sustainable development.

What is the role of hydrology for water resources management? • • 32 Estimation of water resources availability Estimation and reduction of hydrological risks Development of hydrological scenarios Ensure proper information to decision makers