eChapters

The application of agricultural chemicals for control of insects, pests, fungi, weeds and plant diseases plays an important role in crop production. Before 1980 few chemicals were known for control of plant pests.  The chemical pesticides have played an important role in the rapid advancement of agricultural production. Chemical pesticides are getting popular due to non availability of labours especially for weeding operation during kharif season. The chemical pesticides and herbicides are applied with the help of different types of sprayers and dusters.

Fertilizers are required where soils are deficient in plant food elements. When land is planted to crops over a long period of time, the plant food elements slowly get reduced and productivity of crop goes down. Sandy soil looses plant food elements rapidly because heavy rainfall or application of irrigation water leaches these elements out from the soil. Adding chemical fertilizer increases fertility of soil. Principally nitrogen, phosphorous and potassium are added to the soil to promote greater yields. Uniform distribution and proper placement of fertilizer in the soil have become increasingly important factor in providing maximum crop response at minimum cost. Placing the fertilizer near the seeds at the time of sowing results in more effective utilization of nutrients. In the row crops side dressing of fertilizer is done which has immediate benefit when placed in the moist soil within the root zone.

Weeds are a serious menace and these reduce the quality and yield of crops substantially. Chemical as well as mechanical methods are being used to control the weeds. The weeding was traditionally done by “khurpa” up to mid 60s. This tool requires its operation in a sitting posture, which reduces the work rate. The use of long handled tools like “kasola” became popular because these allowed their operation in a standing posture, which increases the mobility and thus the work rate. Weeder is a mechanical device to remove the weeds (unwanted plants) from the cultivated crop. A wide variety of weeders are used in the countries, which may be categorized in three groups viz. manual weeder, animal or tractor drawn weeder and power weeder or self-propelled rotary weeder (Singh, 2007; Pandey et al., 1997; Pandey and Ganesan, 2005).

The seed drills and planters developed and manufactured in advanced countries are designed to meet the requirements of farmers for the different crops and agro-climatic conditions. These machines are capable of operating at high working speed, cover the large area per unit time and provide the desired plant emergence and stand in the fields. The machines are available to handle the seeds of cereals, pulses, oil seeds and other crops widely grown in the developed countries. In developing countries even though these machines can be made available but they are beyond the reach of small farmers. The level of mechanization of sowing and planting is at a very low level.

Tillage operations are the basic operation, which need to be performed at proper moisture and temperature condition (climatic factor) to attain high degree of germination and better plant growth. Tillage may be defined as mechanical manipulation of soil for the purpose of germination and plant growth but it also does the followings:

Introduction

The work on field drains and farm ditches are essential for providing proper irrigation to the crop. Leveling of field is equally important for smooth operation of various field activities including irrigation. Land grading in irrigated agriculture helps in uniform application of water, better water regulation and saving in irrigation time. Land grading helps in conservation of soil and moisture under rainfed conditions. It provides desired surface drainage under irrigated and rainfed conditions. Land leveling helps in the smooth operation of sowing/planting and harvesting equipment.

The Indian agriculture is characterized by agro-ecological diversities in soil, rainfall, temperature and cropping system. Besides favorable solar energy, the country receives about three trillion cubic meter of water from rainfall. Of the total geographical area of 329 million hectares the net sown area has remained at about 140-142 million hectares during the last 40 years. The gross cropped area however has increased to about 200 million hectare in 2011-2012 (Anonymous, 2013). The total operational holding is estimated at 105 million with average size of the holdings of 1.6 ha. The Indian agriculture is not only characterized by small fragmented land, but also hill farming and shifting cultivation are also practiced. Out of an estimated 142 m ha net cultivated area around 40% is irrigated and rest is rain fed. About 65% of the population depend upon agriculture for their livelihood.

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.

Xerophyte: Plant adapted for survival in desert or physiologically dry soil.

Xylem: The water-conducting woody tissue in vascular plants.

Xylomycetophagy: Cultivation and feeding upon symbiotic fungi growing in woody tree tissues; for example, some Scolytidae.

Xylophage (adj. xylophagous): An eater of wood.

Xylophagy: Feeding on xylem tissues.

Yellow fever: An infectious, mosquito-transmitted viral disease.

Wettable powder (WP): An insecticide formulation consisting of finely ground solid particles of active ingredient plus inert carrier; forms a suspension when added to water.

Waggle dance: A communication dance of honey bees. A form of recruitment in the honey bee in which direction and distance to a food source are indicated.

Waiting period: See time interval.

Waiting period: The prescribed period between last application of a pesticide to crop and harvest.

Warble: The swelling on the host body caused by the larva of a warble fly.

Warm-blooded (Homoiothermous): Animals in which body temperature normally does not change with changes in atmospheric temperature e.g.birds and mammals.

Warning: Signal word used to designate a moderately toxic pesticide; oral LD₅₀ = 50 to 500 mg/kg body formulated.

Vagina: A pouch-like or tubular genital chamber of the female genitalia; external opening of the female reproductive system; or the terminus of the female reproductive tract that opens to the outside; or the terminal portion of the female reproductive tract which receives the copulatory organ of a male in mating (L. sheath).

Valid name: The name of a taxonomic category which is available nomenclaturally and also is recognized as valid on Zoological grounds (cf. Available name).

Valvar lamina: The posterior margin (usually prolonged posteriorly) of the eighth abdominal sternite (female Odonata).

Valve: In animals, any structure that limits or closes an opening; the thin folds in veins, lymph vessels, or hearts or the circular muscles about a tubular exit; also, either external shell of bivalve mollusk, brachiopod, or some crustaceans.

Valvifer (s): A basal sclerite of a valve of the ovipositor, articulating with the tergum; or proximal structures of the ovipositor that bear the valvulae; in female insect genitalia, derivations of gonocoxites 8 and 9, supporting the valves of the ovipositor.

Valvulae: Distal structures of the ovipositor borne on the valvifers; the three pairs of processes forming the sheath and piercing structures of the ovipositor.

Ultra low volume spraying (ULV): The application of pesticides in extremely concentrated or undiluted form using 10 liters or less per hectare (1 gal per acre); highly concentrated pesticide applied without dilution at a rate of 0.5 gallons per acre or less.

Umbilical cord: The cord containing blood vessels supported by connective tissue that unites the embryo or fetus of a mammal with the mother during development in the uterus. (L. umbilicus = navel).

Ungulate: Having hoofs, as a deer or (L. ungula = hoof).

Unguligrade: Walking or adopted for walking on hoofs. (L. ungula = hoof + gradior = to step).

Ungue: Pretarsal claw.

Unguiculate: Having claws, as a cat. (L. unguis = claw).

Tactile: Referring to the sense of touch.

Taenidium (pl. taenidia): The spiral thickening of the tracheal wall that prevents collapse; helical fold in the cuticular lining of tracheae and tracheoles (Fig. 230); cuticular ridges that support the walls of tracheae; a spiral or circular thickening of the inner surface of the tracheae.

Sabadilla: A botanical insecticide extracted from seeds of Schoenocaulon officinale

Safener: A chemical additive that reduces the phytotoxic properties of a pesticide.

Salivarium or salivary reservoir: The cavity into which the salivary gland opens, between the hypopharynx and the labium.

Salivary gland: The exocrine gland that produces saliva and typically associated with the labial segment; highly variable in size, structure, and function.

Saltation: Discontinuous variation produced at a single step by mutation (cf. Mutation).

Race: A subspecific category that is based on particular attributes, such as behavioral or physiological (other than morphological) differences; similar to a subspecies; often used in describing plant pathogens.

Race: Subspecies (q.v.).

Race: A naturally occurring group within a species usually visually indistinguishable but with some physiological difference from other members of the species, e.g., with a different plant host range. cf. strain.

Radial cell: A cell bordered anteriorly by a branch of the radius; the marginal cell (Hymenoptera).

Radial cross vein: A cross vein connecting R₁ and the branch of the radius immediately behind it.

Radial sector: The posterior of the two main branches of the radius.

Radiation: See Adaptive radiation.

Quadrangle: A cell immediately beyond the arculus (Odonata, Zygoptera).

Quadrat: A four-sided defined area from which a sample is collected, used in population determination.

Quadrivoltine: Four life cycles per year.

Qualitative defenses of plants: Toxins and small-molecular-weight compounds (such as alkaloids) that are active against the physiological systems of phytophagous insects; complex, digestibility-reducing substances (such as tannins) that reduce the ability of insects to feed on plants.

Quantitative specificity: In serology, the principle that a given kind of antibody will react more strongly, under comparable conditions, with the particular kind of antigen used in its formation than with any other substance (cf. Antibody, Antigen, and Precipitin reaction).

Pacemaker: A region from which waves of contraction in the heartbeat cycle are propagated.

Paedogenesis: Reproduction by the juvenile form; the production of eggs or young by an immature or larval stage of an animal; reproduction by larviform individuals.

Paeudotrachea: A ridged groove on the ventral surface of the labellum of some higher Diptera, used to take up liquid food.

Page precedence: The principle that when two or more conflicting homonyms or synonyms are published in the same work (or portion of a work) and, as a consequence, are of the same date, the names shall have priority according to the sequence in which they first appear in the work (or portion) concerned.

Paint gun: Type of small, hand-carried, air-blast machine.

Pair-wise coevolution: see Specific coevolution.

Objective synonym: An absolute or nomenclatural synonym resulting from the proposal either of a replacement name for a supposedly preoccupied name or of names based on the same specimen, illustration, or taxonomic entity (cf. Synonym, Subjective synonym).

Obligate parasite: A parasite that requires a living host to survive and reproduce and which cannot exist in any other way.

Obligatory: Compulsory, or exclusive; e.g. obligatory diapause is a resting stage that occurs in every individual of each individual of each generation of a univoltine insect.

Oblique sternals: Lateral abdominal muscles in other than longitudinal or dorsal-ventral orientation

Naiad: The immature stage in insects with incomplete metamorphosis that feed and develop in water; an aquatic, gill-breathing, immature instar of hemimetabolous insect.

Narcotic: A chemical that causes reversible depression of the nervous system.

Narrow spectrum (as applied to insecticides): Having an effect on only a narrow range of insects.

Nasus: A nose, the snout of certain termite soldiers (nasutes).

Nasute (pl. nasuti): A type of soldier caste in certain termites; this form bears a median frontal rostrum or snout through which it ejects a defensive fluid; the jaws are small or vestigial.

Nasutus (pl., nasuti): An individual of a termite caste in which the head narrows anteriorly into a snoutlike projection.

Natality: Population ‘increase’ factor; birth rate; often measured as total number of eggs or eggs per female per unit of time.

Macro: Large.

Macro-and microconsumers: In an ecosystem the primary consumers, feed on plants while other consumers, e.g., secondary and tertiary consumers are called macroconsumers. The decomposers, like bacteria and fungi, are called microconsumers.

Macro-and micronutrients: Some salts or elements needed in relatively large amount are termed macronutrients while some others though essential for maintaining the life-system are required in minute amounts and are the micronutrients.

Macroclimate: General climate prevailing over a large area, considered as a unit. The opposite is microclimate.

Macroevolution: Major phylogenetic patterns that develop over wide spans of geological time.

Macrofauna: The larger members of a particular fauna. Open to different levels of interpretation for they may be larger vertebrates or alternatively the larger insects of a habitat. The opposite is microfauna.

Macrogamete: The female gametocyte of a malaria parasite, Plasmodium spp; see also Microgamete.

Macrophage: An eater of large particles; see also Microphage.

Label: Technical information about a registered pesticide in the form of printed material attached to, or printed on, the pesticide container. It is illegal to use the pesticide in ways inconsistent with the label.

Labella (sing. labellum): In certain flies, paired lobes at the apex of the proboscis, derived from labial palps; apical spongelike structure on the proboscis of nonbiting muscoid flies (Fig. 156).

Kairomone: A chemical produced by an individual of one species that has a beneficial effect on the recipient individual of another species; a chemical that is adaptively favourable to the receiving organism; an interspecific messenger substance that benefits the receiver but not the releaser (e.g., attractants, excitants); an interspecific chemical messenger that benefits the receiver but not the emitter; a communication chemical that benefits the receiver and is disadvantageous to the producer; see also Allomone; Synomone.

Karyological character: A character involving chromosome structure or number (cf. Taxonomic character).

Keeled: With an elevated ridge or carnia.

Keratin: The inert exoskeleton protein of vertebrate animals forming skin, hair, feathers, claws, nails, scales, etc.; similar in structure and function to the arthropod chitin.

Keratolytic: Pertaining to or promoting loosening or separation of the outer layer of the skin.

Jet: Liquid emitted from a nozzle orifice (in USA = nozzle).

JH: An abbreviation of juvenile hormone.

Johnston’s organ: A sense organ similar to a chordotonal organ, located in the second antennal segment of most insects; functions in sound reception in some Diptera (Fig. 153); an organ in the pedicel of the antenna, consisting of a cluster of chordotonal sensilla.

Ichthyology: Science dealing with the study of fishes – a class of aquatic vertebrates most of whom depend for respiration exclusively on oxygen dissolved in water (Gr. ichtys = fish + logos = study).

Idiobiont: A parasitoid that prevents its host from developing any further, by paralysis or death; see also Konobiont.

IGR: See insect growth regulator

Ileum: The second section of the hindgut, preceding the colon differentiated region of the anterior intestine of the hindgut preceding the rectum in some insects (Fig. 120).

Imaginal buds: See imaginal disc.

Hard pesticide: One which persists for a long time in the environment; particularly applies to organochlorine insecticides.

Habit, Habitus: The general appearance of an organism; facies.

Habitat modification: Alteration of the environment where an organism occurs, e.g., cultivating land for agriculture.

Habitat: The environmental conditions and associated organisms that occur in a particular site; the place where plants and animals live, usually with a distinctive boundary (e.g. field, pond, sand-dune, rocky crevice); the natural or usual dwelling place of an individual or group of organisms. (L. habitus = condition).

Habituation: A form of associative learning in which a given stimulus no longer elicits a response; learning not to respond to a stimulus that provides no reward or punishment.

Habituation: Reduction in the response to a stimulus with repeated exposure, through modification of the central nervous system.

Haematophagous: Blood-sucking; blood –feeding.

Haemocoel (also hemocoel): The main body cavity of many invertebrates, including insects, formed from an expanded ‘blood’ system that is filled with blood (haemolymph) within which the internal organs lie.

Gain threshold: The beginning point of economic damage, expressed in amount of harvestable produce; when cost of suppressing insect injury equals money to be gained from avoiding the damage.

Galea: The lateral lobe of the maxillary stipes; tonguelike, distal lobe attached to the stipes of the maxilla; an apical lobe of the maxilla of an insect; the outer two-jointed lobe of the “pincers” present on the maxilla of insect mouthparts; in adult Lepidoptera the two are joined and enlarged to form the proboscis. (Fig. 63)

Gall: Swellings, deformities, or growths of plant tissue that result from the activities various types of pests, including bacteria, nematodes, mites and insects; an abnormal growth of plant tissues, caused by the stimulus of an animal or another plant (Fig. 128).

Gallicolous: Living in a plant gall either as the producer or inquiline.

F₁ generation: The first-generation offspring of a particular mating.

F₂ generation: Derived from a mating within the F₁ generation.

Face: The front of the head, below the frontal suture (Fig. 108).

Facet: The hexagonal external surface of an individual compound eye unit of ommatidium.

Facies: In taxonomy, the general aspect, appearance, or habits of a species or group.

Early postemergence: The application of herbicide after plant emergence and during the initial growth phases of crop or weed seedlings.

EC: See emulsifiable concertrate.

Ecdysial cleavage lines: Preformed lines of weakness along which the shed cuticle of the cranium splits during ecdysis; cuticle in the region of these lines lacks the exocuticle (Fig. 100).

Dall code: A code of nomenclature prepared by W.H. Dall at the direction of the American Association for the Advancement of Science (1877).

Damage boundary: The level of injury where damage can be measured.

Damage threshold: Pest population above which crop loss occurs.

Damage: Measurable reduction in crop growth or yield; or a measurable loss of host utility, most often including yield quantity, quality, or aesthetic appeal.

Damping off: Infection of newly formed roots and stems of young seedlings by fungi or bacteria, typically at soil level, resulting in decay or seedling death.

Danger: A signal word used on pesticide labels to inform the user that the pesticide is highly toxic, as defined by FIFRA. The word poison and the skull and crossbones symbol always accompany the signal word danger.

Caecae: Saclike or tubular structures open at only one end (blind), often opening from the mid-intestine (Fig. 41).

Caecum (pl. caeca): A blind-ending tube or sac or pouch sac of the alimentary canal (L. caecus= blind) e.g., haepatic caecae in the alimentary canal of insects (Fig. 41).

Calamistrum: One or two rows of curved spines on the metatarsus of the hind legs (spiders; fig. 608, clm).

Calibration: The adujustment of application equipment so that a defined quantity of chemical or other material is applied per unit time or area.

Calling: A vergin female moth releasing sex pheromones to attract males for the purpose of mating.

Calliphorin: A protein produced in the fat body and stored in the haemolymph of larval Calliphoridae (Diptera).

Bacillus thuringiensis (Bt): Soil-inhabiting bacterium that produces an insecticide effective against larval stages of many species of Lepidoptera, although some strains are effective against various beetle, mosquito, and blackfly larvae.

Backcross: A cross between a hybrid and one of its parents; a cross between a heterozygote and a homozygote (cf. Hybridization, Heterozygous, Homozygous).

Bacterial insecticide: Bacteria pathogenic to insects (e.g., Bt or B. popilliae). Applied using application techniques also used for chemical pesticides.

Bacterium (pl. bacteria): Microscopic, prokaryotic, single-celled organisms having cell walls but lacking membrane-bound organelles. Important in decomposition, nitrogen fixation and other symbiosis, and as pathogens. A significant component of soil food webs.

Bait (B): A pesticide formulation that combines an edible or attractive substance with a small amount of toxic active ingredient (usually about 5%). Baits containing poisonous chemical and food stuffs are primarily offered to pests as food for control of animal pests like mollusks, cutworms, and rodents.

“Age and Area”: The hypothesis (by Willis) that the older a species is, the wider will be its geographical distribution.

A-Without; lacking.

A.I.: See active ingredient.

A.O.U. Code: A code of nomenclature published in 1885 (revised 1908) by the American Ornithologists’ Union for the standardization of bird nomenclature.

Ab-Away from; off.

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.