eChapters

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.

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.

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.

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.

In the Asian and Pacific ‘region, it is China alone which produces the largest quantities of agricultural waste and also crop residues. This is followed by India. From the production of rice, corn and wheat alone 587 million tons of residues are generated per year in China. Maheshwari (2014) has surveyed the proportions of waste that Malaysia generates from the production of rice, palm oil, rubber, coconut and forest products. In Myanmar the crop waste and residues constitute about 4 million tons per year out of which more than half constitutes rice husk.

The possibility of making genetic changes in the laboratory in plants, animals and microbes used in food started almost 10,000 years ago. Along with natural changes taken place during the evolution totally different species have come into existence. This has helped in increased food production with better taste and nutrition. The losses caused by biotic and abiotic stresses from fungi and bacterial pathogens have reduced.

All these methods of utilization and the conversion to useful energies depend on the climate, population density of the area and the basic infrastructure. It is important to work out the market for the products which are produced.
 
Bio-waste management: It needs to take from small actions to the ambitious ones. European Commission proposes to use wastes which could make up to 25% of total energy consumption by 2020. They propose to have directives for the promotion of renewable electricity (Directive 2001/77/EC) and biofuels (Directive 2003/30/EC). The waste production in Europe has gone upto 2 kg per capita per day. Recycling rates are also rising (European Commission, 2017). The Member states must develop a national action plan and outline the national policies to develop existing biomass resources and mobilise new biomass resources for different uses. A European project has studied the amount of renewable energy to be used in 2020. According to them it will be around 195 million tons of oil equivalents (Mton) of biomass which is biodegradable part of MSW. This will be 20% of renewable energy target. It has also been estimated that the amount of bio-energy from the MSW will be 20 Mton, which would account for around 7% of all renewable energy in 2020. This may be available after composting and anaerobic digestion (Atanasiu, 2010).

3a. Sources and problems of agricultural wastes
3b. Waste Reduction
3c. Waste Treatment
3d. Waste Disposal
3e. Clean Technology

Different Kinds of Agricultural Wastes
Table 1: Common Hazardous Wastes: Community Source

After the agricultural activities a number of by-products are obtained and these are known as agricultural waste. These include residues of different crops like stalks, straws, leaves, roots, husks and shells. The animal waste is in the form of manure. All these agricultural wastes are free of cost however; they can be utilized as an important resource (Lionel and Arnold, 1931). Agrawal (1998) has mentioned India as the final dumpyard. The wastes obtained from various resources can be converted into heat, steam, charcoal, methanol, ethanol, biofuel, compost, energy, biogas, construction and high valued chemical compounds. Many times these agri-industrial wastes are not completely utilized and either they rot in open areas or are burned in the fields.

In today’s times, a lot of innovation has come into agriculture. This very hard occupation requires an amalgation of farmers with the scientists. From the rural areas after education the technocrats are moving to the cities and this is creating a great loss to the agriculturists. As the population is growing so is the demand for food. Due to shortage in the storage systems the amount of wastage has increased a lot. It is an important aspect to be looked into. A lot of waste material is seen in the vegetable markets, city markets and near the slums. This causes a lot of pollution and spoils the environment. It is important to know why is it increasing and why the facilities for wastes do not exist.

Vegetation is a key component in hydrologic modeling. Transpiration, a component in hydrologic cycle, is contributed by vegetation. Most of the hydrologic model thus includes vegetation as a parameter. For accurate and appropriate model output, first requirement is good quality data. Most of the time, the data on vegetation is confusing, as in literature various researcher have used different values for common vegetation parameters. Here some common parameters of some important crops, which yield good quality results, are given.

Kharif crops are generally sown during last week of May and first week of June, while rabi crop are sown during last week of November and first week of December. But this period will vary from region to region as well as depends on variety of crop.

More information, more accurate and timely decision. In present high tech world, the more information you have it is easier to make an accurate decision. The information comes in many different ways, from reports to digital photos. A new way to analyze data is a geographic information system (GIS). GIS allows to bring all types of data together based on the geographic and locational component of the data. GIS is a useful tool for seeking innovative ways to solve the problems.

9.1 What is GIS?

A geographic information system (GIS) is a system designed to capture, store manipulate, analyze, manage and present all types of geographically referenced data. GIS can be defined as a computer-based system for digital entry, storage, transformation, analysis and display of spatial data. A geographic information system integrates hardware, software and geographically referenced data for further analysis. GIS allows users to interpret the georeferenced data in many ways that reveal relationships, patterns and trends.

Remote sensing is emerged as an important application of science in all fields for collection of information from a far. This chapter describes the fundamental concepts of remote sensing, electromagnetic radiation (EMR), the interactions between EMR and earth surface features, satellites etc.

8.1 What is Remote Sensing?

Remote sensing is nothing but acquiring information about an object without touching the object itself. In other words, remote sensing is the acquisition of information about an object or phenomenon, without making physical contact with that object. In present era, the term generally refers to the use of aerial sensor technologies to detect and classify objects on the Earth by means of propagated signals. As remote sensing is obtaining information about objects without making physical contact with them, remote sensing can be described as ‘reconnaissance from a distance’, ‘teledetection’ or a form of the common phrase ‘look but don’t touch’.

The artificial neural network (ANN), a data driven model, is inherently suited to the problems that are mathematically difficult to describe. An ANN is a flexible mathematical structure that is capable of identifying complex nonlinear relationships between input and output data sets, where explicit knowledge of the internal processes is not available. In this chapter general structure of ANN is described and also explained briefly with a case study.

7.1 What is Artificial Neural Network?

An Artificial Neural Network (ANN) is an information processing paradigm that is inspired by the way biological nervous system, such as brain process the information. An ANN is an adaptive (Adaptive means that the system parameters are changed during operation i.e. training phase), most often nonlinear system that learns to perform a function (an input/output map) from data. In more practical term, neural networks are non-linear statistical data modeling tools. They can be used to model complex relationships between inputs and outputs or to find out patterns in the data.

Artificial Intelligence (AI) technology is increasingly used in our everyday lives. It is used in a variety of industries from gaming, journalism/media, to finance, as well as in the research fields from water resources to robotics. In this chapter concept and applications of AI are discussed in brief.

6.1 Historical Background

After World War II, a number of people worked independently on intelligent machines. The English mathematician Alan Turing was the first who explained the concept of intelligent machines through a lecture in 1947. He stated that intelligent machines could be developed by programming computers rather than by building machines. Since late 1950 many researchers are working on intelligent machines, mostly on programming computers

Data mining is a powerful technology which helps in extracting future trends and behaviour from large databases. Thereby it helps decision makers to make knowledge-driven decisions. One common form of real-world data is time series. The suitable models are required to analyze time series data. This chapter provides a short introduction to stochastic system, uncertainty, basic statistics time series analysis and some stochastic models.

In this era of computer, mathematical models become integral part of hydrologic studies due to advancement in soft technology. But question always arises as ‘Why should modeling?’ It was well expressed by Rosenblueth and Wiener (1945) as

No substantial part of the universe is so simple that it can be grasped and controlled without abstraction. Abstraction consists in replacing the parts of the universe under consideration by a model of similar but simpler structure. Models, formal or intellectual on the one hand, or material on the other are thus a central necessity of scientific procedure.

Modeling is heart of hydroinformatics. Simulation modeling became integrated part of modern science to justify feasibility of selected option among various competitive alternatives. Simulation modeling is a tool to evaluate the performance of a system, existing or proposed, under different configurations of interest and over long periods of real time. This chapter describes basic concepts, model simulation, model variables, modeling process, model performance etc. in brief.

Data collection is a tedious and time consuming work, particularly from remote places. So many times the collected data is noisy. But data is the base for future planning and management of water resources. Planning based on noisy data could lead to failure. The modern data collection and subsequent control system i.e. telemetry and SCADA, are introduced in this chapter.

Water is a social requirement. Society now become aware about it’s dependence upon water and hence realized the importance of water in sustaining not only the development but also life. Water: too little, too much, too dirty; is general scenario in the world. But with increase in population water become limiting resource and is becoming scarcer and scarcer day by day. As water become scarcer commodity, the users (stakeholders) become more conscious regarding their share in water and ultimately this situation may lead to water conflicts. Earlier water related problems were generally tackled by hydro-engineers, but now in present climate changed scenario these problems go beyond the hydraulics and hydrology. Now a days politicians, ecologists, Non Government Organizations (NGOs), the media and the stakeholders etc are playing a crucial role in decision making in respect to water management issues. Now water projects are designed in reference to social context (Social context means cultural, economic, political, sociological, legal and other such aspects). When social factors are taken into consideration while tackling the water problems, it could not possible to satisfy all involved. Thus it is required to agree upon a compromise solution acceptable to all. Over recent few decades, information and communication technology (ICT) flourishes with great advances. It provides the ways to search for compromise solutions. In this chapter information, hydroinformatics, evolution of hydroinformatics and role of internet in hydroinformatics are discussed.

Introduction

Famous French postmodern philosopher Jean Baudrillard commented on information once. “Information can tell us everything. It has all the answers. But they are answers to questions we have not asked, and which doubtless don’t even arise.” This seemingly paradox observation fits contemporary Internet age perfectly. Internet is a vast repository of information of all kinds and is bursting on its seams. The seeker needs to search with monumental grit and determination to have a full handle on the range of information available for any particular search. A search string for GIS returns more than 1185000 results, in a mere 0.26 seconds. Recommending a comprehensive resource list is not possible as new material gets continually added by way of additions and updates. However for a beginner the list given below will be handy. The flip side is GIS has innumerable resources and a broad range of content. Software vendors, organizations, individuals, universities and companies have provided a wealth of information. The readers are exhorted to make use of the materials to improve their understanding of the subject.

Introduction

The term geographic information systems (GIS) has come to mean, variously, an industry, a product, a technology, and a science. As such, the term invokes different perceptions dependent on whether the viewpoint is that of the software developer, the system marketer, the data provider, the application specialist, or the academic researcher, among others. A newcomer to the field is likely to be bewildered by the multiple uses of the same term, or, seen alternatively, different definitions of the same term. For instance some find it distasteful to use of the conventional acronym GIS and prefer Geospatial Technology. With all the variety of perceptions predicting the future of GIS is a cumbersome business. The most certain inference we can gain from the available trends is, it is growing and is poised for further growth. Geotechnology along with Nanotechnology and Biotechnology is considered as of the three most promising growth industries for the near future.

Topology building

Boolean operations

Query and model building

Customization

Introduction

At human scales, the world consists of objects, events, processes, and a background environment. Cognition is about knowledge: its acquisition, storage and retrieval, manipulation, and use by humans and other intelligent creatures. Cognition includes sensation and perception, thinking, imagery, reasoning and problem-solving, memory, learning, and language. Cognitive structures and process are part of the mind, which emerges from a brain and nervous system inside of a body that exists in a social and physical world. Spatial cognition deals with the cognition of spatial properties of the world, including location, size, distance, direction, shape, pattern, movement, and inter-object relations. GIS design will be largely influenced by spatial cognition.

Introduction

The GIS database is a model of real world. It goes without saying that there is an inherent discrepancy between GIS database and the real world it represents. This is so because all models are fraught with cognitive issues and remain as approximations. To realize the objectives of a GIS, geographical data collected, entered and processed are to be sufficiently error free and reliable.

Errors can be statistical errors like mistakes, wrong inputs or faulty field surveys or system errors like excessive tolerances or high RMS error. The spatial database has further problems in the sense that the real world phenomena are not always intrinsically discrete. For instance where is the bank of a shallow river? Where is the boundary between two soil types? These are but a few questions revealing the fuzzy nature of geographic data. Many soil scientists, geographers have noticed that carefully drawn boundaries or iso-lines on maps in general give misrepresentations of change that are often gradual, vague or fuzzy. Traditional cartography as a medium of spatial data handling had a solution to such problems. But now when digital data are handled, they need to be stored with certain precision. Moreover, the spatial variation of natural phenomena is not just a local noise function or inaccuracy that can be removed by collecting more data or by increasing the precision measurement but is often a fundamental aspect of nature that occurs at all scales. (Goodchild, 1980; Mark and Aronson, 1984). This means residual unmapped variation is a remarkable problem in geographical information processing. It is therefore a prerequisite to fully understand how errors arise or propagated in GIS and what might be the effects of errors on output.

Introduction

Data input or capture is the operation of encoding the data and incorporating in the database. The creation of a clean error free digital database is a complex and critical task determining the very usefulness of a GIS. GIS data represent not only where the graphic or cartographic features occur, but also the associated attributes of them.

Data input to a geographical information system involves

(a) Entering the spatial data (digitizing);

(b) Entering the non-spatial, associated attributes and

(c) Linking the spatial to the non-spatial data.

At each stage necessary verification and checking procedures shall be deployed to ensure an error free database.

Introduction

The concept of database is the approach to information organization in computer-based data processing. (Date, 1995 and Everest, 1986).

A Geographic Information System is as good as the data contained in it. Accurate and efficiently organized data are critical to the durability of the system. Data collection, capture and organization will occupy much of the time in building a GIS solution. The analysis potential of a GIS will depend on the database. It is essential to understand database concepts to practice GIS. It is erroneous to view these GIS databases as mere stores of information. The database is used to abstract very specific sorts of information about reality and organize it in a way that will prove useful during subsequent analysis. The database should be viewed as a representation or model of the world developed for a very specific application.

Conversion of real world geographical variation into discrete objects is done through data models. They represent the linkage between the real world domain of geographic data and computer representation of these features. Data models discussed here are for representing the spatial information.

Introduction

Data are the most critical element of a GIS. It is reported that more than two thirds of the time and expenditure to develop a GIS is spent on data collection and organization. Understanding and appreciating the criticality of data is of paramount significance to practice GIS. This chapter is complementary to database concepts chapter discussed in Level II and deals with the fundamentals to start with and the concepts of building an information organization.

Data - A Definition and Certain Points to Ponder

“Data” are defined as a body of facts or figures, which have been gathered systematically for one or more specific purposes.”

Introduction

All spatial data stored in a GIS are associated with a map projection, either implicitly (so-called “unprojected” data stored with raw longitude, latitude coordinates) or explicitly (where the data have been transformed into a known map projection). Map projections are a particularly important feature of spatial data because they introduce error and distortion, since a sphere cannot be transformed to a plane without some stretching and twisting of the sphere’s surface.

The typical GIS package supports anywhere from 5 to 50 map projection types, and most projections may be modified or customized by varying their parameters. This flexibility is important for two reasons First, in order to use two or more layers together in a GIS for visualization or analysis, all data must be projected in the same way. Second, certain types of analyses, such as the measurement of area, are only valid when using certain types of projections (and conversely, are completely wrong when using an inappropriate projection).

Introduction

In a technology that consistently maintains a fantastic development curve with capabilities doubling up year-to-year, freezing the hardware specification is not easy or very meaningful. GIS (not geography) owes to its genesis and progress to the developments in information technology front. It may be asserted that any and all upgrade in the hardware industry will only add to its own ability to effectively process more and more data and handle more complex routines. The personal computers of today are seen to be adequate to run typical GIS software. A reference hardware specification is discussed here. GIS software development is an involved process but then the software developers have made good use of hardware capabilities available and have released upgrades consistently. Hardware developments are such that they defy a static spcification. However a reference specification as on 2009. An overview of various software packages used in the past as well as present is attempted. ESRI released a new version in 2002 and claimed that their ArcGIS is an “integrated collection of GIS software products for building a complete GIS that enable users to deploy GIS functionality wherever it is needed, in desktops, servers, or custom applications; over the Web; or in the field.” The details are discussed below. While a number of software overviews are available, this text is not aimed at providing a tutorial to any of the software packages nor do the comparisons made are to promote any particular software. Similarly, it is presumed that the reader is familiar with the hardware elements and functionality. Lot of information about the software packages are available on their respective web sites and the reader is exhorted to look for current, additional and in depth information required in the pages. A brief discussion on Liveware or human resource can be found at the end of the chapter.

Introduction

A system is a simplified version of reality and is defined as a collection of interrelated parts that work together. Most systems share certain common characteristics. These common characteristics include the following:
Systems have a structure that is defined by its parts and processes. Systems are generalizations of reality.
Systems tend to function in the same way as nature. This involves inputs getting changed in a process and realization of new outputs.
The various parts of a system have functional as well as structural relationships between each other.
Owing to the functional relationships that exist between the parts there is a flow and transfer of some type of energy and/or matter. In case of information systems there is a flow of information in the structure.
The parts that make up a system show certain degree of integration. In other words the parts work well together.

2.1 Introduction

Rain and snow are the two chief sources of water of the earth. In-situ conservation of rainwater helps the plants to meet some of their consumptive uses directly. Not all the amount of rainwater that falls at a point is conserved by the soil reservoir to support the plant growth. Some part of it flows over the soil surface as surface runoff and some seeps down as infiltration and finally adds to the under ground reservoir. Therefore, rain or snow, which is not used directly by the plants, becomes a potential source of either surface or ground water for irrigation. In areas with extreme low temperature, snow contributes major source of water supply wherever, in humid and sub humid regions, rain is the principal source. Precipitation, rain or snow, is the first stage of the continual cycle of water in its round from atmosphere to the earth and return by evaporation from water bodies, snow surfaces and land surfaces. The continual cycle of distribution of water is governed by the process called as hydrologic cycle. Thus, precipitation or atmospheric water is the first form of water above the earth’s surface, the second form being the surface water on earth and the third form is the subsurface water or underground water. The study of occurrence, distribution and circulation of precipitation through the unending hydrologic cycle forms the basic part of study of hydrology. As mentioned above, the part of precipitation that is not used by the plants in-situ flows over the soil surface as runoff and contributes to either surface or ground water supply.

Introduction

Maize (Zea mays, or corn as it is known in some countries) is the principal cereal crop in tropical and subtropical regions throughout the world. The increasing use of maize as a staple food reflected the much higher yields per hectare, compared with wheat, rye and barley. Because maize was cheap, it became the dominant food and main source of dietary energy and protein for poor people, particularly those in rural and underprivileged segments of society. Maize is considered to be a native of the Americans. There are different views about the introduction of maize in India. One view is that maize was introduced into India by the Portuguese during the seventh century. Other view is that maize was introduced in Pre-Colombian era through the Atlantic Arabian trade route. This is supported by the more recent variability that has been observed in the maize collections made from the north eastern Himalayan region. However, the historic records regarding the cultivation of maize in India date back only to the Maratha Empire.

Introduction

Rice is grown in more than 100 countries in the world and is an important crop for nutritional security of large part of the population. World rice production in 2007 was approximately 645 million tones. Around 50 countries have an annual production of more than 1 million tones. Ninety percent of the total rice is produced in Asian countries, with two countries, China and India, growing more than half the total crop. Top ten rice producing countries are China, India, Indonesia, Bangladesh, Vietnam, Thailand, Myanmar, Japan, Philippines, and Brazil. In Bangladesh, Cambodia, Indonesia, Lao PDR, Myanmar, Thailand, and Vietnam, rice provides 50-80% of the total calories consumed. Major part of the rice is consumed locally where produced and only 6-7% of world rice production is traded internationally.

Introduction

Barley is an important cereal crop grown all over the world and is used mainly for feed and malt purposes and little for human food. Barley is the world’s oldest grain, as evidenced by discoveries in ancient cities in the Middle East and North Africa. It has been cultivated for about 8,000 years, and today is the world’s fourth largest cereal crop. Considerable evidence is available that points to the role of barley as sustaining food source in the evolution of humans. Additionally, alcoholic beverages of various types and fermented foods prepared from barley are commonly referred to in the ancient literature. As other food crops (wheat, rice, corn and rye) became more abundant, barley was relegated to the status of “poor man’s bread”. In the United states, barley used as food is 1.5%, as animal feed 65% and in malt and alcohol production 30% (Newman and Newman, 2006). In 1991, barley used as food in European countries was even lower (0.3%) than the United States. In contrast, during the same time period food was the largest for barley in Morocco (61%), China (62%), India (73%), and Ethiopia (79%). However, current consumer interest in nutrition and human health may help restore barley’s status in the human diet. Nutritional qualities of barley have been known since ancient times. For example, Ajgaonkar 1972 described how ancient Indian physicians effectively stabilized type II diabetics some 2400 years ago. Treatment was remarkable simple and not really different from recommendations that are given to diabetic patients today, i.e., lose weight, change diet, and increase exercise.

Introduction

Improvement of wheat grain quality depends on the knowledge of quality requirements of different end-use products and the genetic components controlling different quality traits. In previous chapters we have dealt in-depth with quality requirements of different end-use products and their genetic components. Depending upon the goal of quality improvement, different strategies are adopted to improve wheat quality. It depends upon the number of genes controlling the traits as well as the availability of the simple methods for phenotyping the traits especially during early segregating generations. In addition stability analysis of the traits across the environments is essential before we go for breeding. Constraints in time, cost, and sample availability usually necessitate the use of predictive tests during early generations, followed by milling and baking tests on advanced lines that have met a number of agronomic, disease and predictive quality criteria. Knowledge of germplasm lines having specific quality traits is needed to initiate breeding for the improvement of wheat grain quality for different end-use products. The quality requirements of different major end-use products are provided in the following table (Table 1).

Introduction

Nutritional value of food stuff is defined by its ability to provide nutrients required by the body. Proteins, carbohydrates, fats, minerals and vitamins are main ingredients in food stuffs. Wheat is an important source of these nutrients. The distribution of nutrients within wheat kernel is typical of many cereals. Nutrients are generally found in the highest concentrations in the germ or embryo and in the aleurone cells surrounding the starchy endosperm followed by bran, whole wheat flour and white flour in decreasing order. Of special importance is that it contains the entire B complex, except for vitamin B12. B vitamins function as cofactors in many metabolic reactions involved in the release of energy. The germ, which includes the scutellum, is especially rich in vitamins B and E, high quality protein, unsaturated fats, minerals, and carbohydrates. The bran consists mostly of the insoluble carbohydrate cellulose, and contains incomplete protein, traces of B vitamins, and minerals including zinc and iron. The endosperm is the largest part of the grain, and consists mostly of the carbohydrate starch, incomplete protein, and trace amounts of vitamins and minerals. Significant variations in the content of grains occur because of variety, crop year, area, fertilizer, and soil type.

Introduction

Carbohydrates constitute nearly 80% of the total dry matter of wheat kernel. Starch is the predominant form, with cellulose, hemicellulose and pentosans present in lesser amount. Starch is present in discrete granules within the cells of the endosperm. Starch content is available in the range of 65% to 75% and generally related negatively to the protein content. Starch structure is a crucial determinant of many end-product uses of wheat. While the amylose /amylopectin ratio is a useful descriptor of starch structure, a more complete analysis of the population of the molecules which constitute a particular starch is considerably more revealing. The molecules range from the high degree of polymerization (10⁷ – 109 glucose units) and heavily branched amylopectin population, to the lower degree of polymerization (103 -106 glucose units), and infrequently branched amylopectin population. Starches with widely differing structures are suited to particular end uses. For example, starches with no amylose, the so called waxy starches are particularly suited to use as thickeners or gel forming agents because they form a clear stable gel with little retrogradation. In contrast, starch with high amylose content form hydrogen bonded insoluble aggregations which are suited to use in adhesives, plastics and as a source of dietary-fibre starch. The size and branching pattern of starch are also important determinants of the suitability of starches for particular end-uses due to the effects these parameters have on gelatinization temperature, starch swelling and viscosity.

Introduction

Bread wheat (Triticum aestivum L.) is one of the most widely cultivated and consumed crops in the world. Wheat is perhaps best known for its different end-use baking properties as determined by grain texture, protein content and quality. Wheat is generally traded by and classified into “hard” and “soft” market classes on the basis of grain hardness or texture of the wheat kernel (caryopsis). Soft wheats have softer endosperm texture that fractures easily, therefore requiring less energy to mill, yields smaller particles, and has less starch damage after milling when compared to hard wheats. Hard and soft are used with slightly different connotations in different parts of the world. In Western Europe, hard is applied primarily to durum wheats and the soft applied to bread wheat. Elsewhere the term is applied to different cultivars within the species Triticum aestivum. In general, hard wheats are used for bread baking, while soft wheats are used for cookies and cake making. Hard wheat requires more force to crack the kernel, maintains a larger particle size, passes through sieves more easily and has more damaged starch MacRitchie (1980). Higher starch damage is required for good bread making quality Tipples et al. (1994) but is detrimental to the biscuit making quality.

Introduction

Wheat is the most important cereal crop to the human kind. It is the main source of energy and nutrition in human diet. Wheat is consumed in the form of large number of end products as chapati, bread, biscuit, cakes, pretzels, noodles and pasta products. Millions of people are involved in milling, baking and pasta products industry with huge turnover per annum. However, each end-use product of wheat has it’s own specific requirement for example basically hard wheats along with strong gluten and high protein content are used for bead making. Soft wheat with weak gluten and low protein content are required for biscuit making Souza et al. (1994). Durum (tetraploid) wheat is used for pasta products as macaroni, vermicelli and spheghatti and Dicoccum for therapeautic purposes. Often chemical improvers are used to improve the dough properties for these products. Most of these chemicals have been banned because of their toxic effects. Therefore, only alternative is to develop varieties suited to meet the requirements of these end-use products. This needs better understanding of molecular basis of grain quality to accelerate breeding for producing wheat varieties for each end-use product separately. Storage proteins are the major component of grain which determines end-product quality. In this chapter detailed structure, genetics and functionality of gluten proteins are described.

Introduction

Dough is a complex mixture of flour constituents, water, salt and other ingredients depending upon the requirements of end-products. It is the principal intermediate stage in the transformation of wheat into different end-use products. Rheological properties of dough determine the behaviour of dough during mixing, rounding and molding used in making different products and also effect on the quality of finished product. Therefore, understanding the various features of dough rheology and their relations with product quality is important. The importance is enhanced further because of mechanization and automation of baking industry. Dough is composed of continuous phase in which gas cells are dispersed. The continuous phase is called “dough phase”. It consists of starch granules embedded in protein matrix along with some lipids, cell remnants and yeast cells in fermented dough. Gas production and retention is the most comprehensive quality requirements of the dough for bread making. The ability of the wheat dough to retain gas during fermentation and oven rise is unique. This depends on the ability of the dough to be stretched into thin membranes because of protein phase.

Introduction

Durum or macaroni wheat (T. turgidum var. durum) is an important crop used chiefly for the production of pasta in Western Europe and North America, and two layered bread, single layered bread, burghul, couscous, pasta, frek and feed in other parts of the world (Table 1). In North Africa and the Middle East, durum is also used for producing flat breads. On a global basis only a small amount of durum wheat is used for baking of pan-style and hearth-style bread. Also, durum wheat for baking is often used in blends with common wheat. In India, durum occupies approximately 2.0 mha area and production is estimated to be around 2.5-3.0 million tones annually amounting to 3-4% of the total wheat production. The consumption of pasta is increasing at the rate of around 5% annually and currently it is estimated to be around 10 Lakh tones. The demand for pasta products may increase further due to increasing population and improving standard of living.

Introduction

For many years it has been an elusive task to provide a precise definition as to what constitutes quality in wheat. Each country has its own traditions in bread and other bakery products. Quality will mean different things to a miller, a baker, a grain handler or a plant breeder. As the baking industry becomes increasingly specialized, specific qualities are sought. Even among those wheat varieties generally recognized as having desirable quality traits, the influence of environment can be substantial, and this necessitates a high level of skill on the part of grain buyers to survey the current year’s crop and blend the wheat for a specific end-use. This genotype X environment effect on quality also limits the capacity of end-users to source identity-preserved wheat from a narrow geographic area. Those of us engaged in the field of plant breeding are concerned primarily with those traits that can be manipulated genetically, and we study their stability under a range of climatic conditions. Constraints in time, cost, and sample availability usually necessitate the use of predictive tests during early generations, followed by milling and baking tests on advanced lines that have met a number of agronomic, disease and predictive quality criteria.

Introduction

There are large numbers of wheat based products such as fermented pan bread, flat breads including chapati, biscuits, noodles and pasta products. Each product has its own specific requirements. For example fermented pan bread needs wheat with higher protein content, stronger and extensible gluten. Chapati requires hard wheat with high protein content and medium gluten strength. Waxy wheats have been found associated with improved shelf life of breads. White salted Japanese noodles need partial waxy wheats with soft grain characteristics and medium protein content and gluten strength. Partial waxy wheats with comparatively lower amylose content and higher starch paste viscosity improve texture of white salted noodles. Yellow alkaline noodles need comparatively harder wheat with medium strong gluten and without waxy trait. Pasta made from durum wheats requires stronger gluten, high protein content and higher content of yellow pigments. In this chapter detailed account of both fermented and flat breads will be given.

Introduction

Wheat is an important cereal crop and is widely cultivated across the world. Wheat is consumed in different forms and major products are chapati, bread, biscuit, noodles and pasta products. Wheat has three groups of cultivated species namely bread, durum and dicoccum wheats. The common or bread wheats account for approximately 95% of world production. Nearly all of the remaining 5% cultivated varieties are durum wheats used for pasta products and couscous and dicoccums represent very little of the total wheat production. The bread wheat is divided into two broad classes based on grain texture; hard and soft. Hard wheats with high protein content and strong gluten are used for making bread and some noodles while soft wheats with lower protein content and weak gluten for biscuit, cakes and pretzels. Semi-hard wheats having some combinations of the above characteristics are utilized for making unleavened breads such as chapati, Asian steamed bread and some noodles. There can be large disparity within wheats of various classes; therefore to provide consistent quality, it is divided into grades. The grading is determined by the test weight, protein content, moisture and foreign material. The major wheat exporting countries have distinct grading patterns designed to provide wheat for specific purposes and consistent quality.

16.1 Introduction

Producing more crops, livestock, fish and forest products per unit of water use is an essence of water productivity and is highly essential for both food and environmental security. A variety of options exist for improving the productivity of water in agriculture through breeding, better management practices and supporting policies and institutions. It is imperative to identify a range of means to enhance water productivity in agriculture, assess their potential and the consequences of their adoption. The production systems to be considered can vary from purely rainfed to irrigated, and from dry zones to semi-humid monsoonal areas.

The productivity of water used in agriculture has almost doubled during 1961 to 2001, It is mainly due to increases in crop yields. Irrigated rice yields doubled and rain-fed wheat yields rose by 160% in that period, with little variation in water consumption per kilo of output. Globally, FAO estimates that water needs for food per capita halved from about 6 m³/day to less than 3 m³/day during 1961 to 2001 which is a significant saving and an equally significant gain for other water users.

According to an estimate, a 1% increase in water productivity in food production enables to save about 24 lit/day of water per head of population, while a 10% increase would equal current domestic water consumption. Importance of saving water in agriculture can be realised from the above observation.

15.1 Introduction

The laws governing the flow of water in wells are referred to as the hydraulics of wells. Just like surface water flows from a higher elevation to a lower elevation by gravity, groundwater also flows from a region of higher water table to a region of lower water table. This difference of water table measured by any two piezometers divided by the longitudinal distance between them is called as hydraulic gradient. Hydraulic gradient plays a dominant role in deciding the flow of groundwater. This hydraulic gradient together with the hydraulic conductivity of the aquifer material forms the main law of well hydraulics called as Darcy’s law. An understanding of Darcy’s law together with some other laws as discussed subsequently in this chapter is essential in order to know the discharge of a well in a particular formation. Darcy’s law is valid for studying groundwater flow in alluvial formations. However, it is not valid for aquifers having hard rock areas.

14.1 Introduction

Groundwater is an important source of water for irrigation. It is the most abundant fresh water resource of the earth. Underground water reservoirs contain large stock of fresh water resources. Total quantity of groundwater within 800 m distance below the ground surface is more than 30 times the total water in all fresh water lakes, more than 60 times the total water in soil and other unsaturated rock materials, more than 300 times the water vapour in the atmosphere and 3000 times the average volume of all rivers and rivulets in the world (Lenka, 2001). But the distribution of groundwater is not uniform. At some places, it lies below a few metres whereas at other places, it is a thousand metres or more below the ground surface. In some places, there is abundant groundwater potential whereas at other places there is meager potential.

Groundwater is the water reaching the groundwater reservoir from the infiltrated water of precipitation which constitutes an important component of the hydrologic cycle. It is only the part of the subterranean water that occurs in the saturated pores of the containing rock materials underlain by water held in a zone of aeration. It should not be confused that all the water present in soil below the ground surface is groundwater.

13.1 Introduction

In agricultural lands, when the pores of the soil within the root zone of the crop get saturated with the subsoil water due to infiltration of high rainfall, excess irrigation or heavy seepage loss in the unlined canal systems, the air circulation within the soil pores get totally stopped. This phenomenon is called as waterlogging. In canal commands where there is continuous flow of water in the canals and canals are mostly unlined, there is heavy loss of seepage which raises the ground water table. This raising water table sometimes comes up to the ground surface which impedes surface drainage. By capillary action, under ground water rises to the crop root zone and submerges the roots of the crops for most of the time. This situation is called as waterlogging which creates salinisation and alkalinisation problems affecting the plant growth.

The height to which soil water rises above the water table by capillary action is called as capillary fringe. Generally, the height of the capillary fringe varies from 1 to 1.5 m. When the water table comes to 1.5 m below the surface of the soil, the land is said to be waterlogged. At times, due to poor drainage conditions, surface water cannot be freely drained out. The stagnate water in these low lying areas also causes waterlogging which enhances the weed growth consequently affecting the crop yield.

12.1 Introduction

Rainfall is the major source of water that contributes lion’s share for irrigation to crops. Before it reaches the earth, it is to a great extent pure in nature. By the time it falls on the ground surface, it comes in contact with various types of gases and suspended materials of the atmosphere and also after it flows as runoff on the surface it gets dissolved with many types of salts, impurities etc. that render the water to be impure. Many a time the industrial waste, agricultural wastes, pesticides, fungicides, chemical fertilizers etc. get mixed with water and make it unsuitable for irrigation use. Water being a universal solvent, it dissolves all most all organic impurities, salts etc. which makes it objectionable for both domestic and agricultural uses.

Irrigated agriculture is dependent on an adequate water supply of usable quality. In the past, water quality concerns were neglected because good quality water supplies were plentiful and readily available. This situation is now changing in many areas. Especially, in the arid and semi-arid zones, water quality is fast deteriorating which is posing threat to irrigated agriculture.

Conceptually, water quality refers to the characteristics of a water supply that will influence its suitability for a specific use. On the other hand, it refers to the situation of how well the quality meets the needs of the user. There are three quality indicators. They are physical, chemical and biological indicators. Even a personal preference such as taste is a simple evaluation of acceptability. For example, if two drinking waters of equally good quality are available, people may express a preference for one supply rather than the other; the better tasting water becomes the preferred supply. In irrigated agriculture, emphasis is placed on the chemical and physical indicators of the water and rarely the biological indicator is considered important.

11.1 Introduction

The entire amount of water that is diverted at the canal head regulator does not reach at the field for use of irrigation. Major amount of it is lost on way during its movement in the canal systems. During the passage of water from main canal to outlet at the head of the water course, water may be lost either by evaporation from the surface or by seepage through the peripheries of the channel. These losses are sometimes very high, and may go up to 50 % of the total water diverted into the main canal. Evaporation losses are low and may go to a maximum of about 7 percent.of total losses. The major loss of water in the conveyance system is the seepage loss. Seepage loss depends on the channel geometry and evaporation loss is proportional to the area of free surface. In determining the designed channel capacity, a provision of these water losses must be made. The provision for the water lost in the watercourses and in the field however, already made in the outlet discharge factor, and hence no extra provision is made on that account. However, excluding the above two losses, there is operational loss which when added to the evaporation and seepage losses, the total losses goes up the maximum 50 percent level. The operational loss includes spillage, over-toping, leakage through rodent holes, dead storage, initial infiltration and evapotranspiration from the vegetation along the watercourse. Evaporation and seepage losses of the canals are discussed below.