eChapters

Hydraulic turbines is a device which transforms the hydraulic energy or potential energy existing with the working medium to mechanical energy. The working medium is normally water which run the hydraulic turbine. The hydraulic energy is available with water by virtue of its height or altitude. The water which flow through the mountains is stored by constructing a dam or reservoir.

In drip irrigation water is distributed throughout the field from a system of pressurized pipelines. The pressure must be sufficient to overcome the frictional losses and elevation differences. The system also deserves discharge from all the emitters and the emitters must dissipate the pressure difference between the inlet to emitters and atmospheric pressure.

The flow through the drip pipes may be laminar or turbulent or a combination of both. The laminar flow is characterized by the layers of cylindrical tubes of which the maximum velocity is at the center about double of the average velocity. The turbulent flows having pulsatory cross current velocities and maximum velocity is about only 1.25 time of the average velocity. Turbulent f lows loss more energy than laminar flow due to development of the cross current velocity.

Reynolds Number

The criterion for distinguishing the flow from laminar to turbulent was developed by Osborne Reynolds (1842-1900) and was named as Reynolds number; Re . The Reynolds number in circular pipes flowing full is expressed as

11.1. Hydraulic system

It is a mechanism in a tractor to raise, hold or lower the mounted or semi-mounted equipment by hydraulic means. All the present day tractors are equipped with a hydraulic control system for operating three point hitches. Some of the tractors are fitted with a hydraulic brake system and a few others are fitted with a hydraulic steering system. Tipping trailers, front mounted loaders or dozers are examples of multi use of hydraulics.

11.2. Principle

The working principle of a hydraulic system is based on Pascal’s law (Fig 11.1.) This law states that the pressure applied to an enclosed fluid is transmitted equally in all directions. A small force acting on a small area can produce higher force on a surface of larger area.

14.1 Introduction

Hydro-electric power is electricity produced by the movement of fresh water from rivers and lakes. Gravity causes water to flow downwards and this downward motion of water contains kinetic energy, that can be converted into mechanical energy, and then from mechanical energy into electrical energy in hydro-electric power stations. (“Hydro” comes from the Greek word hydra, meaning water). At a good site hydro-electricity can generate very cost-effective electricity.

Hydro-climatology is defined as the investigation of the impact of climate upon the waters of the earth. This topic includes hydrometeorology, the water processes of evaporation (surface and near surface), rainfall-runoff, and groundwater studies (Langbein, 1967; Wendland, 1998). Hydroclimatology provides a systematic foundation to assess how the climate system causes spatiotemporal changes in the hydrologic cycle with respect to global or local aspects. Variations in the relationship between the hydrologic cycle and the climate system underlie droughts, floods, and future impacts of global warming on available water resources. Both land and satellite based data and computer programming and modelling contribute to our knowledge of the spatiotemporal changes of physical processes shared by the hydrologic cycle and the climate system (Shelton, 2009).

Abstract

The Mesozoic sediments contribute around 54% of the oil and 44% of the gas reserves of the world (Bois et al. 1982). Indian Mesozoic basins occupy an area of about 400 x 103 sq. km and are characterized as frontier basins under category II - IV. These basins are mostly overlain by the Deccan Traps of Late Cretaceous age and are least explored. Deccan Syneclise is one of the largest Mesozoic basins in India, covering an area of ~ 273 x 103 sq. km. Geophysical studies have inferred hidden sub-trappean Mesozoic sediments with thickness up to 2.5 km. It is considered that requisite heat generation due to Deccan Trap volcanism soon after the Cretaceous sedimentation may have acted as a catalyst in hydrocarbon generation. Surface geochemical prospecting surveys along with carbon isotopic studies have been used to assess hydrocarbon generation potential of this part of the basin. The area adjoining Nandurbar beneath Narmada-Tapti region of Deccan Syneclise was selected for geochemical studies where geophysical studies have shown considerable sediment thickness. Surface geochemical studies indicate the generation of light gaseous hydrocarbons, C1 and SC2+ in the range of 3 to 1187 ppb and 1 to 1449 ppb, respectively. The carbon isotopic signatures of selected soil gas samples dC13 CH4 in the range of - 24 to -39.4‰ PDB) suggest thermogenic origin

Abstract

A total of 30 groundwater samples were collected in four different seasons (Pre Monsoon, South West Monsoon, North East Monsoon and Post Monsoon) from the coastal aquifers of Kalpakkam region of Tamilnadu. The samples were collected covering the seasonal and lithological variations to infer the influence of natural geochemical processes and anthropogenic sources on the groundwater chemistry. The collected samples were analysed for the parameters like EC, pH and Major ions. The saturation index of silicates and carbonates shows that state of saturation to over saturation, but the sulphate minerals is dominantly under saturated. In the inverse modeling three models are obtained using PHREEQC and the error percentage is noted as 7.45%.

Abstract

In Gadilam river basin, groundwater is found in both hard rock and sedimentary terrain and is the most important source of rural/urban drinking water supply. Gadilam river basin has gained its importance due to the presence of Neyveli Lignite open cast mine (NLC), group of industrial estate (SIPCOT), extensive depressurization of Cuddalore aquifer and boreholes of New Veeranam Scheme (NVS) in the downstream of the basin. A total of 178 water samples were collected in four different seasons at various lithologies. The collected samples were analyzed for various physico-chemical parameters using standard procedures. Geochemical indicators of groundwater were used to identify the chemical processes that control hydrogeochemsitry. Interpretation of hydrogeochemical data suggests that leaching of ions followed by weathering and anthropogenic impact controls the chemistry of the groundwater. Isotopic study reveals that recharge from meteoric source in sedimentary terrain and rock water interaction with significant evaporation prevails in hard rock region. This thorough understanding helps us to make judicial usage and to maintain the quality of this commodity.

Abstract

Quality of water is affected by natural and man induced contamination to groundwater system. Area chosen for study has gained its own importance due to the location of two lignite mines and a Thermal power plant in operation. Extensive large scale pumping of water is done for lignite mining. The mine drainage and drainage from thermal power plant along with agricultural return flow from lignite charged waters increases the severity of problem. In order to achieve a panacea for the above-mentioned situation, the study has incorporated and integrated in all related factors to get a meaningful interpretation for groundwater quality and quantity management in and around Neyveli area. The frequent failure of monsoon has added to the existing problem of over exploitation. To attain a panacea for water chemistry groundwater samples were collected for four different seasons. Higher EC and TDS values are observed in Southeast and Southwest part of the study area. In Southwest monsoon and Summer seasons HCO₃Cl dominates the anions, with few representations for SO₄. In Northeast monsoon and Post monsoon season Na + K – Ca + Mg is the dominant. Thermodynamic, studies reveal that groundwater of the region are stable with Kaolinite stability field in all the silicate systems. Bicarbonates derived from silicate mineral weathering are noted in the NW, Northern and in the mining region. These regions are located in the NW and NE part of the study area. Comparison of water quality to standards shows that the water can be used for drinking and for irrigation purposes except in few locations.

ABSTRACT

Mecheri Panchayat union lies in the northwestern part of Salem district and adjascent to Dharmapuri district of Tamil Nadu. It lies between the latitudes 11°43’ -12° and longitudes 77° 48’ -78° 03’ of Toposheet No. 58 E/13 of scale 1:50,000 published by survey of India in 1973. Mecheri Panchayat union covers a total area of about 177.6 Sq.Km with a population nearly 1 lakh, live in 150 hamlets. Groundwater is the only replenshable nature resources available to man. The use of groundwater has been growing steadily over the years for domestic, agricultural and industrial purposes. Hydrogeochemical study is a dynamic process undergoing constant change in space and time. In unconfined aquifers, the change likely to be quite rapid and cyclic in nature with respect to the mode of recharge and discharge and related to the nature of host aquifer. In this study an attempt has been made for understanding the chemical quality of groundwater in theunconfined aquifer of Mecheri union. Groundwater samples have been collected from 10 representative dug wells lying in the Mecheri union during December 2004 and analysed by the standard procedures of water analyses. It is essential in determining its usefulness for domestic, industrial and agricultural purposes. Presentation of Geochemical data in the form of graphical charts such as Collin’s bar, Stiff’s polygon diagram, Pie diagram, Piper tri linear diagram, USSL classification and thematical maps were prepared for recognizing various hydrogeochemical types in the Mecheri union. Deleterious effects of fluoride on the human beings are well known. Fluoride are known to be beneficial, when present in concentration ranging from 0.5 ppm to 1.2 ppm. But when it exceeds the limit 1.2 ppm it is found to cause fluorosis. Dental, skeletal and non-skeletal fluorosis may be caused depending upon the concentration of fluorides in drinking water. The main source of drinking water for the majority of people of Mecheri union is groundwater obtained through dug and bore wells. The analysis of groundwater samples showing high (> 1.5 ppm) fluorite content observed in the following villages, viz Mallikundam, Kuttapatti Aranganur, Banapuram, Sathappadi, Mecheri town, Virudasampatti and Amaram.

ABSTRACT

The sources of fluoride in groundwater are minerals like fluorite, apatite, mica, amphiboles,cryolite and fluor.spar. The undue concentration of fluoride greater than 1 mg/l has befallen a major toxicological and geoenvironmental issue in India. Excess of fluoride in groundwater causes skeletal and dental fluorisis. The study area forms part of Salem district with records of endemic fluorisis. To decipher process and chemistry of fluoride, a total of 46 groundwater samples were collected from major litho units of the study area (Peninsular gneiss and Charnockite) and analyzed for fluoride using standard procedures for two seasons viz. pre and post monsoon. In pre-monsoon, maximum and minimum fluoride in Peninsular gneiss and charnockite were ranging from 2.85 to 0.4 mg/l and 4.02 to 0.37 mg/l respectively. The coresspnding figures in post monsoon ranges from 2.84 to 0.32 mg/l and 1.91to 0.37 mg/l respectively. Higher concentration was noted in charnockite folowed by peninsular gneiss in pre monsoon and the effect of dilution was well noted in post monsoon season. Statistical analysis undercovers the relationship of fluoride minerals with other ions. Modeling results represent the leaching of fluoride minerals and their variation along with seasons.

Introduction

Water is among the most precious gifts of nature to mankind. Most of the ancient towns of the world grew on the banks of the river, and some of the ancient civilizations are known by the names of rivers. Rivers have always been important sources of drinking water and the means of sustaining human, animal and plant life. Whenever one is dealing with water resources development and utilization, it has to be kept in mind that not only quantity of water but also quality of water is very important. The well being and development of our society is dependent on the availability of water. An increase in groundwater development and utilization for industries and urban water supply has created improper disposal of liquid waste. Defective well constructions, sewage and waste disposal in man made lakes with in the city, open quarries with water and failure to seal the abandoned wells in city area have provided possible openings for downward movement of polluted water into subsurface formations without undergoing the process of natural filtration.

INTRODUCTION

Remote Sensing is an indigenous tool for the Environmental Impact Assessment study. It plays vital role in preparing various thematic maps for understanding the changes that have taken place in an area before and after the establishment activities. In this study we have utilized the capability of the remote sensing techniques in understanding the mining environment. Our study area is in and around the Dalmiapuram Cement Industry in the central part of Tamil Nadu state and it covers part of Trichy and Perambalur districts. It falls between 11₀ 02’ 42’’and 1₀ 03’ 08’’E and 79₀ 09’ 39’’and 79₀ 10’ 30’’N.Dalmiapuram Cement Industry is located in the Kovandakurichi village of Pullambadi block, Trichy district. The mines for cement manufacturing are Perianagalur (PNR), Periathirukonam (PTK), Kallakudi (KLK), Kovandakurichi (KVK) and A&K Mines.

The litho units are Limestone beds containing various proportions of bioclastic and siliciclastic materials. They show wackstone to rudstone fabric and have clasts of re-deposited bound stones. Deposition in a periodically restricted shallow marine setting was indicated by lithological and faunal information. Lower contact is an unconformity surface associated with marine flooding and the upper contact is non-depositional and erosional with overlying biostormal member.

Common groundwater investigations include necessary considerations of the system’s influx sources, flow regime, discharge points and geomorphological characteristics of the area. Often, hydrogeomorphological mapping of an area is required as to determine these characteristics. The primary data can be acquired from the survey of India toposheet map and the satellite images. The secondary data set includes the satellite imageries, the preparation of digital elevation model (DEM) and digitized precipitation maps.

The first step in the procedure of hydrogeomorphological mapping is to calculate the watershed/basin area, which serves as a mask to define the area of interest. The watershed/basin calculation relies on the digital elevation data and assumes that topographic aspect (dip direction of the cell surface) completely controls the extent to which surface flow emanating from each point in the study area can reach the low point in the valley. The calculation of the potential annual recharge of the aquifer combines techniques described above with data for recharge areas, DEM aspect, and precipitation. First, the catchment area of the recharge zones must be calculated in a process similar to the watershed analysis, returning the area associated with the catchment coded as “1”. A simple multiplication overlay with the precipitation data and the catchment areas yields a result giving the amount of precipitation for each catchment cell. Before using the precipitation data, we converted it to meters so as to keep units consistent. The precipitation amounts within the catchment area (i.e. each cell value) are to be summed, yielding the amount of water available for influx into the groundwater system. Finally precipitation per year data can be acquired.

Identifying surface areas of groundwater discharge is based on the observation that such areas provide a relatively constant source of moisture, which is readily exploited by vegetation in semi-arid region. Thus areas with year-round green vegetation are assumed to be indicators of discharge. The relative amount of vegetation in a scene can be estimated by calculating a vegetation index (Reddy et al, 1989 and Tucker 1979).

The world is head98ing towards a water crisis. Africa and West Asia are likely to be worst affected by water scarcity, but with increasing population, water may fall short even in the other parts of the world. According to the recent UN report, the supply of clean and fresh water is depleting at such an alarming rate in some regions, that within 30 years, about two third of population will suffer moderate to severe water stress.

In hydrogeomorphological context of social environment the water is an essential natural resource for sustaining life. The available water resources are under tremendous pressure due to increased demands. The time is not far when water, which is the free gift of nature, will become a scare commodity. Therefore, conservation and preservation of water resources are urgently required to be done at priority basis. Water management has always been practiced in our communities since ancient times. But such practices have faded away during the past few decades mainly due to lack awareness. Hydrogeologists feel that the water harvesting practices must be urgently implemented to overcome the problem of water crises. In India the Ministry of water Resources is endeavouring to make rainwater harvesting a part of every day life in villages and cities as a people’s movement. Hydrogeomorphological aspect of social environment include (a) Social - Cultural -Administrative Consideration (b) Education and Training in Hydrogeology for Professionals and Technicians (c) Education for Farmers and Women (d) Education for Masses. These are described as below:

The beginning of the 20^th century was heralded by methodological revolution in geomorphological studies brought in by Davis (1899). His classical model of geographical cycle defined by him ‘ as a period of time during which and uplifted landmass undergoes its transformation by the process of land sculpture ending into a low featureless plain (peneplain)’ dominated the geomorphological investigations all over the world throughout 1^st half of the 20^th century.

The statistical techniques by Horton (1932 and 1945) brought quantitative revolution in the field of geomorphology when he presented quantitative analysis of morphometric characteristics of fluvially originated drainage basin. Post 1950 geomorphology has undergone vast change in the methods and approaches to the study of landforms, conceptual framework, paradigm and thrust areas of study. The most outstanding contribution to the advancement of geomorphological knowledge in this period is the adoption of quantitative approach based on deductive scientific method to the study of landforms and processes at short spatial and temporal scales (Strahler, 1956 and Schumm, 1956).

Several attempts have been made in the world in past to classify large territories and landforms into morpho-units. Valuable contributions pertaining to landform analysis have been summarized below: Joerg (1914) subdivided North America into natural regions, Fenneman (1914) established physiographic boundaries and gave physiographic divisions of the United States, whereas Anderson (1941) gave physiographic divisions of Columbia plateau. Howard and Spock (1940) and Weaver (1965) presented the excellent ways of classification of the landforms while Wood and Snell (1960) applied the quantitative systems for the classification of the landforms. However, Linton (1951) and Hammond (1954 and 1965) gave techniques for mapping delineating small scale and large-scale landforms.

6.1 Introduction

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

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.

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.

Hydrological cycle involves four major steps, Viz., Evaporation, Transpiration, Condensation and Precipitation. Though the cycle has neither a beginning nor an end, the concept of cycle begins with the water of oceans, since it occur nearly ¾ of the Earth’s surface. Radiation from the Sun, evaporates water as water vapour from the oceans into the atmosphere. The water vapour rises and collects to form clouds. Under certain condition, the cloud moisture condenses and falls back to the Earth as rain, snow, hail etc. Precipitation reaching the Earth surface may be intercepted by vegetation or enter into the soil, may flow as run-off or may evaporate.

Evaporation may be from the surface of the ground or from free water surface. Transpiration may be from plants.

Condensation: The physical process by which a vapour becomes a liquid or solid – opposite of evaporation.