The work discusses the principles of evaporation as one of the processes in the hydrologic cycle and the different methods to estimate the evaporation rate. Four different methods namely the energy balance, aerodynamics, combination method and Priestley-Taylor method are included in the discussion. In the end there are some examples with solutions.
Evaporation is the process that liquid water enters the atmosphere as water vapour and replenishes the humidity of the air. It is also considered as the pathway in which the water travels from its liquid state back into the hydrologic cycle as an atmospheric water vapor. Water bodies such as oceans, seas, lakes and rivers provide nearly 90 % of the moisture in the atmosphere through evaporation, as some study reveals.
Table of Contents
1.0 Introduction
2.0 Evaporation
3.0 Principles of Evapotranspiration
4.0 Estimation Methods of Evaporation
4.1 Energy Balance Method
4.2 Aerodynamic Method
4.3 Combination Method
4.4 Priestley-Taylor Method
5.0 Sample Problems
Objectives and Topics
This work aims to provide a comprehensive overview of the principles of evaporation within the hydrological cycle and to detail the mathematical methodologies utilized for estimating evaporation rates in various environmental conditions.
- Fundamental principles of the evaporation and evapotranspiration processes.
- Detailed application of the Energy Balance method for rate estimation.
- Analysis of the Aerodynamic method focusing on vapor transport factors.
- Implementation of the Combination and Priestley-Taylor methods.
- Practical calculation examples for professional engineering and hydrological applications.
Excerpt from the book
4.2 Aerodynamic Method
The first factor controlling the evaporation is the heat energy which was the main concern of the Energy balance method, but the second controlling factor is the ability to transport vapor. Aerodynamic method is concerned on this factor which is governed by the humidity gradient and wind speed.
Summary of Chapters
1.0 Introduction: This chapter introduces evaporation as a critical component of the hydrologic cycle and outlines the four primary estimation methods covered in the text.
2.0 Evaporation: This section defines evaporation as a physical process and identifies the key meteorological factors, such as solar radiation and wind, that influence it.
3.0 Principles of Evapotranspiration: This chapter explains the simultaneous occurrence of evaporation and transpiration in vegetated areas and defines the concept of Potential Evapotranspiration.
4.0 Estimation Methods of Evaporation: This chapter provides the theoretical framework and mathematical equations for the Energy Balance, Aerodynamic, Combination, and Priestley-Taylor methods.
5.0 Sample Problems: This chapter provides step-by-step practical calculations for determining evaporation rates using the previously introduced mathematical models.
Keywords
Evaporation, Hydrologic Cycle, Evapotranspiration, Energy Balance, Aerodynamic Method, Solar Radiation, Latent Heat, Humidity Gradient, Wind Speed, Potential Evapotranspiration, Priestley-Taylor Method, Vapor Pressure, Hydrology, Engineering Estimation
Frequently Asked Questions
What is the primary focus of this work?
The work focuses on explaining the physical process of evaporation and detailing the scientific methods used by engineers and hydrologists to calculate evaporation rates.
What are the main thematic areas covered?
The main themes include the physics of the water cycle, the influence of vegetation on moisture transport, and the application of specific mathematical models to estimate water loss.
What is the central research objective?
The primary objective is to equip the reader with the theoretical knowledge and practical calculation skills necessary to apply different evaporation estimation methodologies.
Which scientific methods are analyzed?
The text analyzes four specific methods: the Energy Balance method, the Aerodynamic method, the Combination method, and the Priestley-Taylor method.
What does the main body of the work address?
The main body systematically explores the principles behind each evaporation estimation method and provides detailed worked examples to demonstrate their practical application.
Which keywords characterize the work?
Key terms include Evaporation, Hydrologic Cycle, Energy Balance, Aerodynamic Method, and Potential Evapotranspiration.
Why is the Priestley-Taylor method included?
It is included because it provides a useful estimation approach specifically for conditions where detailed weather inputs like wind speed and relative humidity are unavailable.
How is the Energy Balance method calculated?
It is calculated by treating the latent heat flux as the residual term in the general energy balance equation, accounting for net radiation and sensible heat.
What is the purpose of the provided sample problems?
They serve as practical demonstrations of how to apply the theoretical formulas to real-world data, such as calculating evaporation rates based on specific temperature and radiation readings.
How is the roughness height utilized in the Aerodynamic method?
The roughness height is a parameter used within the vapor transfer coefficient calculation to account for the impact of surface characteristics on the ability to transport vapor.
- Quote paper
- Florante Jr Poso (Author), 2019, Estimation Methods of Evaporation. Examples for Revision, Munich, GRIN Verlag, https://www.grin.com/document/464154
