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1986 | Buch

Hydrological Forecasting

Design and Operation of Hydrological Forecasting Systems

verfasst von: Jaromir Nemec

Verlag: Springer Netherlands

Buchreihe : Water Science and Technology Library

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In the past two decades several activities in the field of water resources management have been enhanced and intensified. This . rise had at least two independent reasons. The first and main one was the constantly increasing water demand for agriculture and industry on one side and the concern about the deteriorating environment on the other. While this last concern was lately overshadowed by deterioration of national economies, the quantity of available water resources has certainly not increased with the growing scarcity of funds for its development and protection. Furthermore, the standard of living, which raised across the world, even in India and China, countries which concentrate more than a third of the world population, has made people and their governments more aware of natural disasters caused by weather. Since a large percentage of losses in human life and material damage from weather-related disasters are caused by water, either by its excess or scarcity, the concern about water has been increasingly associated with these disasters. The second reason for intensified water resources management is man's spectacular technological advance in electronics, computers and use of satellites. The Koran says that two things cannot be predicted: the sex of the child in its mother's womb and the quantity of water that falls from the sky and flows in rivers. Technological progress has disproved both of these caveats.

Inhaltsverzeichnis

Frontmatter
1. Introduction
Abstract
Hydrological forecasting is the prior estimate of future states of hydrological phenomena in real time, not to be confused with hydrological design-data computation (prediction)*. While the actual use of the words “forecast” and “prediction” is a matter of semantics or convenience, the substance of the technical activities connected with each is basically different. Both these activities require historical data (time series) and may use the same or similar methods of hydrological analysis and modelling. However, hydrological forecasting comprises additional technical activities connected with other hydrological and non-hydrological subjects, such as network design, data processing, remote-sensing techniques, telecommunications, operational use of computers, etc. In view of this, the subject of hydrological forecasting should not be viewed as one particular hydrological technique, but as an economic activity using many technological developments, both hydrological and non-hydrological. Thus a prior knowledge of hydrological analysis and modelling, of network design techniques, of telecommunications and remote-sensing systems, of on-line and off-line computer use, etc., is necessary if the activity of hydrological forecasting is to be exercised successfully and efficiently.
Jaromir Nemec
2. Components of hydrological forecasting systems
Abstract
A concrete HFS system depends on many conditions which, in addition to those of a technical nature and the natural environment (basin and river), include the social and administrative structures of the specific country. For this reason a general description of the design and operation of the components of a HFS can include only those sub-systems which are indispensable for the system in general.
Jaromir Nemec
3. Selection of forecasting procedures
Abstract
In order to help national services to evaluate different forecasting procedures, mainly deterministic conceptual models, WMO conducted, from 1970 to 1975, an intercomparison project of conceptual models (WMO, 1975) for rainfall-runoff modelling and from 1976 to 1983 a project for intercomparison of snowmelt runoff models. A third project, to compare updating procedures and model behaviour in real-time operational conditions, which permit updating and improving of models behaviour is to be conducted in 1987.
Jaromir Nemec
4. Forecast updating and evaluation
Abstract
The forms in which forecasts are issued are basically set from the beginning of an HFS design by the real or potential user’s need. They depend on all elements by which the forecasts are classified (see section 1.4) namely on forecast variables, type of forecast, forecast lead time as well as means and frequency of forecast dissemination.
Jaromir Nemec
5. Benefit and cost analysis of hydrological forecasts
Abstract
In section 1.1 are enumerated reasons for establishing a HFS for different purposes, specified in section 1.4. Indeed the best reason for the establishment of such systems, particularly in developing countries, are examples of their benefits derived either in developed, industrialized countries or in neighbouring developing countries with similar climatic conditions. It should however be noted, that the benefits are not always the same and thus in a more careful analysis, during periods of national financial stringencies, the question will necessarily arise, if an HFS is an endeavour worth the investment. In the case of specific climatic conditions, such as those existing in regions subjected to tropical cyclones (typhoons, hurricanes), the justification of establishment of flood forecasting systems needs hardly a substantiation. Indeed the consideration of the following numbers will probably be sufficient.
Jaromir Nemec
6. Examples of design of HFS in WMO-assisted projects
Abstract
This system was designed in 1969 and commissioned in 1974. The rivers concerned were the Niger itself from its source to its confluence with the River Bani in Mali, and its main tributaries, the Milo and Tinkisso in Guinea and the Sankarani and Bani in Mali. A total of 77 hydrometric and rainfall stations were taken over by the project and available for the calibration of the forecasting models. At the beginning of the project, 12 stations were equipped with radio-transmitters and could be used for real-time data transmission, and thus for operational forecasts. The size of the basin and its physiography, consisting of the high mountains of Fouta Djallon in the upper reaches of the rivers and of flat valleys entering the arid plain of the middle reach after the confluence of the Niger with the Bani (the inner delta of the Niger), required more detailed real-time information on the flows and rainfall. For this reason 15 additional radio stations were established, each to transmit both rainfall and discharge data daily during the rainy and flood season, including the period of flood recession. The total of 27 radio stations were installed so that each larger tributary could be monitored by a discharge station, either before or after its confluence with a river of second or first order (Niger).
Jaromir Nemec
Backmatter
Metadaten
Titel
Hydrological Forecasting
verfasst von
Jaromir Nemec
Copyright-Jahr
1986
Verlag
Springer Netherlands
Electronic ISBN
978-94-009-4680-4
Print ISBN
978-94-010-8580-9
DOI
https://doi.org/10.1007/978-94-009-4680-4