eChapters

Abstract

Drying is an age old practice of food preservation. Removal of moisture from the food materials is usually carried out at atmospheric pressure and elevated temperature. In the presence of oxygen, drying can cause oxidation of some compounds leading to quality deterioration. Drying at higher temperature adds to the losses and can be responsible for enzymatic and non enzymatic browning, loss of aroma, nutrients, antioxidants, pigments etc. On the other hand, drying under sub atmospheric pressure helps in retaining the themosensitive compounds present in natural foods as drying can be accomplished in oxygen free environment. Under vacuum, evaporation of moisture can be possible at lower temperatures.

Abstract

Refractance Window (RW) drying is a relatively new drying technology. This method is carried out by spreading a thin film of food slurry on a conveyor belt made up of a transparent polyester material. The slurry is thermally heated as it moves along the conveyor belt, resulting in rapid drying of the product. RW drying is similar to Drum Drying, but conducted at lower temperatures (95–97^ºC) and without direct contact with the heat source. RW drying offers low operating costs with excellent retention of color, flavor and nutrients.

Abstract

Fruit leather is a concentrated source of nutrient, energy and minerals processed from fruits in the form of sheet or leather. It is eaten as a desert or snack since ancient time. Fruit leathers have a greater benefit than fresh fruits if equilibrium ingredients are established and seasonal surplus of fruits are utilized and contributed to minimize post-harvest losses. The process of making fruit leathers involve making fruit puree and adding additives and preservatives for the purpose of enhancing taste and shelf-life. Drying, the key unit operation in making fruit leathers, is the most energy intensive and time consuming step in the process, modern drying techniques can be implemented to overcome the limitations. By novel means of processing technologies or enrichment could lead fruit leather to introduce high quality food product in the market. Continuous research and development can lead to a new era of production and development of fruit processing and overcome the obstacles during processing. In addition study on chemical and biochemical hazards involved in overall process will guide to ensure product safety. Market research tools e.g. quality function deployment method and other market analysis methods could be applied to understand the product trend, demand, consumer expectations and the scopes of improvement.

Abstract

Medicinal herbs are economically and nutritionally important plants, which are rich in health-promoting compounds. Herbs are the backbone of both the traditional Chinese and Indian medicine, which has long history as part of their culture. Ensuring the quality of herbs is a crucial step for integrating the traditional medicine into science-based modern medicine. Drying is an essential technique in preservation of herbs as it affects directly the quality attributes of the dried products, whereas many producers lose much profit due to poor drying techniques. So, employing a suitable drying technology and selection of appropriate drying conditions are very important for producing high quality herb products. The aim of this article is to summarize the advances in drying technologies of medicinal plants, describe the current status and identify future research opportunities. The current work provides more data and information for selecting optimum technology for herb drying and would trigger innovative drying technologies to enhance drying kinetics and quality of herb drying.

Abstract

Food proteins are among the commonly used ingredients by food manufacturers to produce different products with desired characteristics. Due to several nutritional and functional properties, proteins have different functions in various food products in addition to their role in metabolic system of the human body. Dilute or concentrated solutions of pure proteins or unprocessed food products which are rich in protein are very sensitive to deterioration or degradation by microorganisms and thus have short shelf life at ambient temperatures due to their highly moist structure and high protein content. Drying is one of the best methods that can guarantee preservation, a longer shelf life, chemical or thermal stabilization and resistance against other stresses. A full understanding of stresses encountered during drying is needed to choose an appropriate drying process and to optimize this process for maximum product quality. A number of methods have been used by various researchers to dry protein-containing foods. Among these methods, freeze drying and spray drying are the most common techniques. Sun drying, convective hot air drying, vacuum drying, heat pump drying, radio frequency drying as well as combined or hybrid drying methods with two or more of the drying methods have also been developed.

Abstract

Application of solar energy for drying of agricultural food products is one of the most attractive and cost-effective drying techniques. However, the intermittent nature of the solar energy is one of the major shortcomings of the solar drying system that can be alleviated by storing excess energy during the peak time and using it in off sun hours or when the direct availability of solar energy is inadequate. The use of sensible and latent heat storage systems in solar dryer is an effective way of storing thermal energy for drying purpose. This chapter will present information on different thermal energy storage (TES) materials, their advantages and disadvantages. The information available in the literature regarding the studies conducted on TES assisted solar drying systems is also covered in this chapter. In addition, some of the models that have been used by different researchers to test the performance of different TES materials are also reviewed.

Abstract

Drying remained at the centre stage since the initiation of the food processing due to its promise to preserve agricultural products economically and add functionality to a food product unlike other thermal as well as non-thermal food processing operations. However, many existing drying techniques have their own limitations like nutrient loss, damage of the organoleptic quality, high cost etc. Therefore, research for better drying technologies is going on. Supercritical drying (SCD) is one such technology which utilizes higher dissolving power of super critical fluids (SCFs) to dry food products. The current chapter illustrates the mechanism of SCD as well as current state-of-art and promise of the drying technology. Also, some modelling approach of SCD has been included in the discussion to facilitate new designs and optimization of SCD for various food products.

Abstract
 
Spray drying is used as one of the best alternatives for extracting essential constituents of fruit and vegetables. Spray drying of fruits and vegetable juice/purees, which is an excellent source of bio-functional properties into a solid phase helps to enhance their stability and controlled release in different food matrices. Spray drying along with different carrying agents helps to retain essential active compounds in fruits and vegetables. Spray drying is generally carried in three steps viz. atomization of liquid feed by suitable atomizer; drying of droplets with the help of hot air and motion of droplets. Carrier agents like maltodextrin, wax starch, Gum Arabic and microcrystalline cellulose are added to the feed to increase glass transition temperature. Chapter presents the effects of different operating parameters of spray drying as well as effects of carrier agents on the physicochemical and functional properties of spray dried fruit and vegetables powders.

Abstract

Dietary antioxidants can be found naturally in various fruits, vegetables and food products.Typically, antioxidant phytochemicals commonly found in food products are Vitamin C, Vitamin E, carotenoids, polyphenols, melanoidins and indoles. The main characteristic of an antioxidant is its ability to scavenge free radicals and form stable end product which inhibit the chain oxidative mechanisms that lead to degenerative diseases which are harmful to human health. Drying is widely used in food processing to minimize food wastage and to extend food shelf-life. Pretreatment, drying methods and storage conditions are some of the processing parameters affecting the quality of dried products. Selection of processing conditions and storage environment are therefore critical in maximizing the retention of food antioxidants. This chapter aims to compile and summarize studies carried out for antioxidants namely antioxidant contents in dried food products, effect of processing parameters and quantification methods in the analyses of antioxidants.

Abstract

Water, the most important component of common foods, is considered to be desirable as well as undesirable in the different food systems. Water-solid interaction in food systems controls various biological, biochemical and biophysical reactions affecting their acceptability. The retention or release of water from solid has been quantified in the terms of sorption isotherm. Sorption isotherm techniques have been used to characterize and identify the type of water-solid interaction in different food products. Sorption isotherm provides various information useful in designing and optimization of drying, storage, packaging, predicting quality and shelf life of the product.

Abstract

Most dryers operate at low thermal efficiency. The development of models and control systems offers an opportunity to improve dryer operation and efficiency. Dryer control is very important and with deeper understanding of the drying concept, new “smart” dryers can be made more reliable and more cost-effective than classical dryers. This chapter will provide an overview of necessity of control and safety measure in food drying system, and terminology related with drying control system. Different control strategy includes conventional and advanced techniques implemented in drying operation are reviewed  here and simple outline of intelligence control system in drying technology are briefly described in succeeding section. Various hazards in drying process and risk and safety management will also be discussed.

Abstract

Packaging plays an important role in the food processing Industry. It makes food more convenient as well as gives the food greater safety assurance from microorganisms, biological and chemical changes such that the packed foods can have longer shelf life. In order to meet the huge demand of processed food with longer shelf life, various methods of preservation and packaging are being used in the food processing industry. Drying and dehydration is one of the method which helps preservation of a perishable commodity against deterioration or spoilage.

Abstract

By loosely inspiring the actions of neurons in the human brain, artificial neural networks (ANNs) are widely accepted as a powerful nonlinear adaptive approach to tackle complex, dynamic, highly nonlinear, and ill-defined problems in an increasing number of fields of food industry.They have been used extensively in food drying to solve problems of nonlinear function approximation, pattern recognition, data description, optimization, simulation, pattern recognition, control, data sorting, clustering, and noise reduction, due to their massively parallel structure and capability to learn from examples. In this chapter, after providing a brief description of ANN technology and its principles as well as the structure of the most commonly employed ANNs in this context, an example is given to explain how the ANN technique is used for modeling and controlling food drying process. Generally, modeling, prediction, and optimization of heat and mass transfer, thermodynamic performance indicators, and quality parameters as well as physico-chemical attributes of dried foods are the most popular subjects to attract researchers’ attention to apply the ANNs in food drying industry.

Abstract

Inspired by the human eye to brain assessment process, computer vision technology has demonstrated its potential for monitoring and controlling of several operations in food industry. Computer vision technology is, therefore, applied extensively in food drying process for monitoring nutritional value and sensorial characteristics because of its promising characteristics such as reliable objectivity and repeatability. In this chapter, after providing a brief explanation of the computer vision technology and its prerequisites and principles, an example is given to elucidate how this technology is used for monitoring the visual attributes of foodstuffs during drying process. Overall, monitoring the visual properties of food products like size, shape, color, and texture in off-line mode are the most popular issues to fascinate researchers’ attention to apply the computer vision technology in food drying. Nevertheless, industrial applications of the computer vision technology for real-time monitoring and control of food drying facilities as final goals of its introduction in food drying industry seem to be limited. For future studies, it is suggested to apply this unique technology along with advanced soft computing methodologies for in-line monitoring and control of food drying process in order to achieve high quality dried products. Finally, outlooks and potential employment of this technology in food drying domain are discussed as well.

It is difficult to ascertain which came first, food or human being. It is the same situation as chicken and egg where we lack evidence to indicate which came first on earth.

It does not matter which came first but we know for sure that human being needs food and he or she needs everyday and throughout his or her life. In other words, a human being cannot survive without food indicating permanent unbreakable bondage between food and human being. It supports the basics of human civilization-food, agriculture and humanity.

1.    I deem it a singular honour to deliver Dr. Sen Memorial Lecture. Dr. Sen, who was both an administrator and a visionary, was instrumental for:

SYNOPSIS

Food is an essential element without which human being cannot survive. We need it for our maintenance and growth everyday and through the longevity of our life. As we understand food, it is a bunch of essential elements which is essentially needed for the engine of human body to run non-stop. The understanding of food is much required by masses who consume it every day. The present paper attempts to describe the knowledge on food, feeling on food by consumers, prevailing food, hunger and malnutrition, healthy food and studies required on consumable foods.

SYNOPSIS

We lag in nutritional awareness. The therapeutic values of plant foods, such as vegetables, fruits, grains, legumes, nuts, seeds, herbs, spices and other foods like dairy products, fluids and meats are to be brought to light. The values of important nutrients, may lead to the basis for nutritional education lacking at present. There is need to bring awareness and add to the knowledge of the younger generation. A food is something that provides nutrients. Nutrients are substances that provide: energy for activity, growth, and all functions of the body such as breathing, digesting food, and keeping warm; materials for the growth and repair of the body, and for keeping the immune system healthy.

SYNOPSIS

The availability of food is of paramount importance without which it is hard for human beings to survive. The recognized way of making food available is to produce but it is also equally important that food produced is utilized well without loss of edible food materials. The paper discusses on unused food, under- utilized food within and across countries, and puts emphasis on utilization and handling of food. In perspective, the paper highlights the steps to be taken up to save and utilize the food already produced.

SYNOPSIS

In all probability the ancient farmer’s market originated on the streets of villages and later on, on the streets of towns. The street food survived through decades and centuries and now it has assumed its new role in fulfilling the readymade food demand of the working people of mega cities. The street food has now more relevance to the growing urban population. With the lapse of time and migration people to the cities, the business and activities of street food got expanded in qualitative and quantitative terms worldwide.

SYNOPSIS

With the change of time, and the progressive development in life-style, the menu of food has undergone significant changes in communities, countries, regions and worldwide. This is influenced by the travel, migration of the people, and enhancement of the socio-economic status among the masses.

SYNOPSIS

Nature produces plants with healing properties. Hundreds of phytochemicals and antioxidants have been identified in various food plants. Many plants or plant parts are eaten as food. There are several plant species which are cultivated for food, and many have several distinct cultivars. Seeds of plants are a good source of food for animals, including humans, because they contain the nutrients necessary for the plant’s initial growth, including many healthful fats, such as Omega fats. In fact, the majority of foods consumed by human beings are seed-based foods.

SYNOPSIS

Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal or fish origin. Plant foods are the most abundant sources of nutrition on earth. Only plants contain powerful substances called phytochemicals, which protect us from cancer, heart disease, and an array of other serious illnesses.

SYNOPSIS

Many plants or plant parts are eaten as food. In addition to essential vitamins, minerals, and fibers, plant foods contain phytochemicals and antioxidants, which actively provide protection against diseases. Several studies carried out all over the world have demonstrated the protective values of fruits. Fruits are the ripened ovaries of plants, including the seeds within. Many plants have evolved fruits that are attractive as a food source to animals, so that animals will eat the fruits and excrete the seeds some distance away.

SYNOPSIS

Animal source foods (ASF) include any food item that comes from an animal source such as meat, milk, fish, eggs, cheese and yogurt. Many individuals do not consume ASF or consume little ASF by either personal choice or necessity as ASF may not be accessible or available to these people. Animals are used as food either directly or indirectly by the products they produce. Animal source foods (ASF) include any food item that comes from an animal source such as meat, milk, fish, eggs, cheese and yogurt.

SYNOPSIS

Fish has now become an important animal protein for mankind. It is a rich source of essential amino acids, vitamins and minerals. Fish meat is easily digestible compared to other animal meat and has a higher Protein Efficiency Ratio when compared to casein, the milk protein. Fish oils like body oils of fishes like sardine, mackeral, anchoviella, herring, salmon etc. are the richest source for Omega-3 long chain poly unsaturate fatty acid like Eicos- pentanoic acid (EPA) and Docosahexaenoic acid (DHA) having therapeutical applications for man. A number of fishery products and by-products like squalene, chitin, chitosan, oyster meat, mussel meat, shark bones etc.

SYNOPSIS

Flavor is the sensory impression of a food or other substance, and is determined mainly by the chemical senses of taste and smell. The flavor of the food, as such, can be altered with natural or artificial flavorings which affect these senses. Smell is the main determinant of a food item’s flavor. While the taste of food is limited to sweet, sour, bitter, salty, umami (savory), pungent or piquant, and metallic – the seven basic tastes – the smells of a food are potentially limitless.

SYNOPSIS

Vegetables are essential for well-balanced diet since they supply phytonutriceuticals. About 3 billion people in the world are malnourished due to imbalanced diets. Regular consumption of a vegetable rich diet has undeniable effects on health since they have been strongly associated with improvement of gastrointestinal health, good vision, and reduced risk of heart disease, stroke, chronic diseases such as diabetes, and some forms of cancer.

SYNOPSIS

There is an increasing awareness about quality of food among consumers all over the world. Organically produced food is considered to be nutritionally superior, but the available information is not conclusive.

SYNOPSIS

There have been conflicting practices, recommendations regarding a healthy diet in human beings. Unscientific food habits are limitation to good health and active life. Because of various social, cultural, religious and economic factors human beings in the same climatic conditions and living situations, have been practicing different food habits leading to many health problems. What to eat, how much to eat and when to eat are not clear with the masses. This paper attempts to throw light on these aspects.

SYNOPSIS

Human health is defined as a state of physical, mental, physiological and social well being. It is also considered as a state of body and mind, where there is a balance of body humors or secretions. The paper introduces the readers to common diseases caused through various agents like deficiency disorders, food and water, air-borne, vector, viruses, and life-styles. It also describes healthy food, health management, food management, and healthy life style.

Note: With my personal experience, I have learnt many lessons during the course of my journey of life. The reader should ponder over it and prepare own food profile and menu for the benefit of maintaining good health. My paper does not provide any prescription but provides illustration of my experiences only, which may be of some use in knowledge and practice of food. The medical and health experts need to be consulted as appropriate.

Synopsis

If the human being was born first, he or she needed food immediately to survive. Thereafter, human beings continued to need food and continued to eat food throughout his or her life. Hence, the relationship between human being and food is permanent and the requirement of food for the human being to be alive is everlasting. The paper provides the background, definition of right to food, and adequate food, historical events, legal perspectives, operational guidelines, and advances in its application and derives conclusion.

SYNOPSIS

Inspite of the fact that governments in various food summits and conferences have made commitments on food and nutrition security, presently more than a billion people are suffering from hunger and malnutrition worldwide. The food and nutrition policies need to be revisited and updated to address both man-made food scarcities and natural disasters of present and future to mitigate hunger and malnutrition.

On different occasions I have expressed my views on hunger and food security. Here are some of the views published earlier.

1. Food Security bill: Why it is an opportunity lost

Several years ago I and Dr M S Swaminathan were speaking at a conference on hunger at Rome. Also speaking at one of the sessions was the Brazilian Minister for Zero Hunger Programme, the dream programme of ex-President LuizInácio Lula da Silva. After he had listened to us, he sat down with us to know of how India was battling hunger, specially the way India was managing its food self-sufficiency and the massive food procurement programme.

SYNOPSIS

Urban and rural agriculture are different entities in terms of stakeholder involvement and enabling environment for farming but they are dialectically interlinked in providing food and nutrition security of any country. Urban agriculture is more suitable on the production of nutritious crops, while rural agriculture’s first priority is to produce more food from staple. Attaining nutrition security is more complex than it is previously thought. However, while existing systems of production should continue at field levels by developing more nutritionally rich cropping patterns, its integration with farmers’ farming systems remains more important.

Synopsis

Food safety has become increasingly important with globalization due to various factors such as increased volume and diversity of trade in foods, greater public demand for health protection, changing hazards e.g., resistant microbes, more sophisticated methods for detection of hazards, changes in production and consumption pattern, etc. Food safety contributes significantly to food security as unsafe and poor quality food leads to illnesses as well as food wastage. This leads to a strong need to emphasize not only on availability of food but also ensure that the same is safe.

SYNOPSIS

Food security is a complex issue, linked to availability and access to food, malnutrition in the population, economic development, environment, and local and global trade. Malnutrition hinders healthy growth and proper development of the human immune system affecting neurological and cognitive development especially in children.

SYNOPSIS

India has been conspicuous as one of the most malnourished nations, as every child out of two is malnourished. Moreover, the levels of under nourishment is substantially high among tribal communities. The present investigation has been made to examine the levels of food insecurity at the micro level in four regions identified in the tribal dominated areas of Maharashtra on the basis of macro level indicators. A comparison of food insecurity between the two communities reveals a high incidence of food insecurity among the tribal as compared to that of non-tribal. The nutritional status of tribal children is much lower than that of their non-tribal counterparts.

SYNOPSIS

Food and nutritional challenges continue to be tackled in East and Southern African countries. Prevailing rates of high malnutrition among children and often in adults in vulnerable geographical locations do suggest the need for appropriate interventions. Of several global nutrition interventions during the 1980s, successful implementation of nutrition programmes in Tanzania, Uganda, Malawi and Ethiopia have established strategies / approaches that are promising.  In Tanzania, the Iringa nutrition programme (WHO/UNICEF Joint Nutrition Support Programme) was implemented during 1983-1988.

SYNOPSIS

After the break-up of the Soviet Union in 1992, the countries of Central Asia and the Caucasus (CAC) began making the transition from controlled to market economies. All of the countries have programs for economic and social development as well as food security. Over the last decade, the regional population increased 11%, from 72 million in 2002 to 79 million in 2012. Agricultural production has increased throughout the region. For example, vegetable production per decade has nearly doubled due to an increase in the area of the crops grown and to increased yields, and was more than 19 million t in 2011.

The present publication has highlighted the issues on different aspects of food sector expressed by very distinguished authors. The issues have been discussed and illustrated how we conceive food as an item, what and how much food is known to consumers, what are common food sources, the relationship between food and health, food and nutrition security programmes in different regions of the world and how do we perceive food and nutrition policy challenges?

1.1 Water and its Importance

Water has played a crucial role in sustainace of lives of all living beings including animals, plants and human beings in this earth since time immemorial. It is there since the creation of the nature and will probably remain till the destruction of the nature. It is used in multifarious uses including domestic, industrial, agricultural, recreational and many other uses. It occurs in the nature in practically three forms i.e. solid, liquid and gaseous forms. All the three forms are important to living beings; but the liquid form of water is more beneficial. The weight of the water helps in running hydroelectric turbines, the density of water helps in floating the ships, the steam energy produced by heating the water helps to run the locomotives and thus is beneficial in many ways. It is considered as the most important resource of the society. It has become part and partial in our life so that we cannot live without water. That is why water is called as life.

2.1 Introduction

Precipitation is the general term for all forms of moisture emanating from clouds and then ultimately falling on the land surface. It is the total supply of water derived from the atmosphere in the forms of rain, snow, hail, mist, dew, sleet, fog etc. The liquid form of precipitation is called as rainfall whereas the frozen forms of precipitations are snow, hail and sleet. Of all the different forms of precipitation, rain and snow are the two dominant factors that contribute maximum amount of water. In Indian condition, rainfall is the most important form of precipitation that contributes the highest amount of water causing stream flow. Unless otherwise stated, the term rainfall will be used in this book synonymously with precipitation. It is the primary input vector of the hydrologic cycle. Generally it is expressed as the depth water on a horizontal surface over any specified time interval. If the specified time interval is day, then the amount of precipitation is called as daily precipitation. Similarly, the precipitation being contributed over time interval of a month, season and year is termed as monthly, seasonal or annual precipitation. Its form and quantity are influenced by the action of different climatic factors such as wind, temperature and atmospheric pressure. The study of precipitation forms a major portion of the subject of the hydrometeorology.

3.1 Runoff

Runoff is one of the important parameter of hydrologic cycle. It is defined as that portion of precipitation which is not absorbed by the deep soil strata but finds its way into the stream after meeting the demands of evapotranspiration, interception, infiltration, surface storage, and surface as well as channel detention. It includes surface runoff received into the channels after precipitation occurs, delayed runoff that enters the stream after passing through the land surface, and other delayed runoff from the temporarily detained pits, depressions, swamps or detained as snow fall. It is thus the flow collected from the drainage basin and appearing at the outlet of the basin. The runoff process is demonstrated in Fig. 3.1 as flow chart. Details of the runoff process are discussed as below.

4.1 Introduction

Precipitation is a major component of hydrological cycle. It occurs because of condensation of water vapour molecules in the atmosphere. When the precipitation falls on the grounds, it undergoes several phases before it appears as runoff in the streams. Certain amount of precipitations is intercepted by the foliage of plants and roofs and other parts of the building and other hydraulic structures. This intercepted water is called as interception loss which is evaporated to the atmosphere. Sometimes the dried surface of the buildings and other structures soak certain amount of precipitation while falling on them which also adds to interception loss. After striking the land masses, certain amount of the precipitated water gets infiltrated into the soil surface which then moves both in lateral as well as in vertical direction. This loss is called as infiltration loss. For the study of groundwater, infiltration loss is not a loss but rather it is a gain in terms of groundwater recharge. However for a surface water hydrologist, it is a loss since it decreases the amount of runoff contributing to the stream or any other water bodies.

5.1 Introduction

A steam can be defined as a flow channel in to which the surface runoff flowing over the land surfaces and base flow/ground flow flowing below the ground surfaces meet. It receives the total flow from a specified basin. Streamflow representing the runoff phase of the hydrologic cycle is the most important basic data for hydrologic studies. Interestingly, stream flow is the only part of the hydrologic cycle that can be measured accurately. Stream flow is a historical data and like rainfall and runoff, it is a stochastic hydrologic variable. It is also called as discharge or rate of flow. Discharge is defined as the volume of water flowing through a cross section in a unit time.

6.1 Introduction

When rainfall strikes a ground surface, some losses like initial and infiltration will occur. After these losses are fulfilled, runoff will begin. The runoff will ultimately reach a stream. The main routes through which runoff flows are (i) overland flow, (ii) interflow and (iii) groundwater flow. Overland flow which is also called as surface flow flows over the land mass and reaches a stream. Overland flow soon reaches a stream and if it occurs in sufficient quantity, it forms an important element in the formation of flood peaks. In small and moderate storms, there may have predominant initial and infiltration losses resulting minimum amount of surface runoff and this is especially true in case of permeable soils. If the soil is impermeable, then there may have reasonable runoff. However, surface runoff is an important factor in streamflow only for heavy or high intensity rainfall.

7.1 Introduction

Flood is an unusually high stage in a river resulted due to high rainfall or snow melt which causes large flow of runoff in it. During flood, the river overflows the banks and inundates the adjoining areas. Flood causes heavy damages to buildings and hydraulic structures besides causing catastrophic loss to human life and property. It causes great economic loss due to disruption of many structures and damage to agricultural fields. Many forest and aquatic lives are affected by the flood. Hundreds of crores of rupees are spent every year to control, forecast and manage the flood.

8.1 Introduction

The knowledge of statistics and probability is very helpful for correct prediction of hydrological data and correct prediction of hydrological data is useful in giving good performance in all water resources projects. Since hydrological data are highly stochastic varying both in space and time, it is essential to predict them as correct as possible. The hydrologic evens do not depend on physical and chemical laws but depend entirely on nature. They cannot be predicted exactly by using any relationship but can be predicted at different probability levels by fitting suitable probability distribution functions. Application of statistics and probability in the field of hydrology can help to predict the hydrologic events in a better way. In hydrology, objectives of statistics are as follows (Suresh, 2008):