eChapters

Clouds are visible mass of little drops of water or frozen crystals suspended in the atmosphere above the surface of the earth. The World Meteorological Organisation defined cloud as a visible aggregate of minute particles of water or ice or both, in the free air. This aggregate may include larger particles of water or ice and particles such as those present in fumes, smoke or dust.

Clouds are the most important form of suspended water droplets caused by condensation. The typical size of these water droplets and ice crystals range from less than 1 µm to 50 µm. When surrounded by billions of other droplets or crystals, they become visible as clouds. In the atmosphere sufficient moisture is required to allow condensation to take place. Then, moisture needs a suitable surface upon which it can condense. In free air, condensation begins on hygroscopic nuclei such as aerosols. These are microscopic particles and include dust, smoke, salts and chemical compounds. Nuclei range in size from 0.001 µm radius to over 10 µm. On an average, oceanic air contains one million condensation nuclei per litre and land air holds some 5 or 6 millions. On hygroscopic particles such as sea salts, condensation can begin before the air is saturated. Supersaturation in clouds rarely exceeds one per cent. On average, clouds contain only four per cent of the total water in the atmosphere at any one time. Almost all clouds exist in the troposphere, although the tops of some severe thunderstorms occasionally extend to the stratosphere. Clouds move along with the wind and remain stationary in calm winds. They grow vertically and horizontally, depending on the temperature of the cloud and its ambient temperature. They may dissipate or precipitate. Under favourable atmospheric conditions, they burst and fall as rain. Clouds are essential to the earth-atmosphere system. They complete the following functions.

Cloud has been defined as a visible aggregation of minute water droplets and / or ice particles in the air, usually above the ground level.

CLASSIFICATION OF CLOUDS

Though confusion apparently arises from the number of kinds or species, the genera seems reasonably clear out, if we are able to recognize their main characteristics.

Clouds are usually classified according to their height and appearance. For convenience, we list them in descending order. High clouds, middle clouds and low clouds are some forms do not fit in any of these categories. But fortunately their particular characteristics make them easily identifiable as vertical development clouds. We must exercise some caution in studying on height. There is some seasonal as well as latitudinal variation and there is some overlapping from time to time. However, the appearance of clouds is quite distinctive for each height category.

Clouds are visible mass of little drops of water or frozen crystals suspended in the atmosphere above the surface of the earth. The World Meteorological Organisation defined cloud as a visible aggregate of minute particles of water or ice or both, in the free air. This aggregate may include larger particles of water or ice and particles such as those present in fumes, smoke or dust.

Clouds are the most important form of suspended water droplets caused by condensation. The typical size of these water droplets and ice crystals range from less than 1 μm to 50 μm. When surrounded by billions of other droplets or crystals, they become visible as clouds. In the atmosphere sufficient moisture is required to allow condensation to take place. Then, moisture needs a suitable surface upon which it can condense. In free air, condensation begins on hygroscopic nuclei such as aerosols. These are microscopic particles and include dust, smoke, salts and chemical compounds. Nuclei range in size from 0.001 μm radius to over 10 μm. On an average, oceanic air contains one million condensation nuclei per litre and land air holds some 5 or 6 millions. On hygroscopic particles such as sea salts, condensation can begin before the air is saturated. Supersaturation in clouds rarely exceeds one per cent. On an average, clouds contain only four per cent of the total water in the atmosphere at any one time. Almost all clouds exist in the troposphere, although the tops of some severe thunderstorms occasionally extend to the stratosphere. Clouds move along with the wind and remain stationary in calm winds. They grow vertically and horizontally, depending on the temperature of the cloud and its ambient temperature. They may dissipate or precipitate. Under favourable atmospheric conditions, they burst and fall as rain.

Coastal areas are defined as the interface or transition areas between land and sea, including large inland lakes. Coastal areas are diverse in function and form, dynamic and do not lend themselves well to definition by strict spatial boundaries.

Economic importance of coastal areas

Many of the world’s major cities are located in coastal areas, and a large portion of economic activities are concentrated in these cities. The coastal zone is an area of convergence of activities in urban centres, such as shipping in major ports, and wastes generated from domestic sources and by major industrial facilities. Many of the world’s most productive agricultural areas are located in river deltas and coastal plains, which contribute for national economic growth.

Introduction

India contains around 7517 km of coast line, which is surrounded by the Arabian Sea on the west, the Bay of Bengal on the east, and the Indian Ocean to its south. The Indian Coastal ecosystem, where land and water join to create an environment with a distinct structure, diversity, and f low of energy. They include salt marshes, mangroves, wetlands, estuaries, and bays and are home to many different types of plants and animals. (Marale. 2013). The geographic and land use details of Indian coastal zone is presented in Table 1.

Coastal ecosystems of india

India has a long coastline of 7,517 km that span 13 maritime states and union territories, surrounded by the Indian Ocean, Arabian Sea and Bay of Bengal. It has an Exclusive Economic Zone of 2.02 million square kilometers. The country has a diverse range of habitats: continental area and offshore islands and a variety of coastal ecosystems such as estuaries, lagoons, coral reefs, mangroves, salt marshes, sea grass beds, backwaters, rocky coasts, mudf lats, sand dunes, and coastal beaches. Coasts and islands form 2.8% of India’s geographical area. The coastal ecosystem consists of 43,230 km² of coastal wetlands with 97 major estuaries and 34 major lagoons; 4921 km² of mangroves with 31 mangrove areas, and 3062.97 km² of coral reefs with 5 coral reef areas (MoEFCC, 2018). A network of 14 major, 44 medium and numerous minor rivers together with their tributaries with a total length of over 40,000 km, contribute to the coastal sea directly or indirectly. By area, tidal/mudf lats are predominant and by length, more than half of the Indian coastline is sandy. The states of Gujarat, Tamil Nadu and Andhra Pradesh have extensive coastline (Fig. 1).

This chapter documents shoreline changes of the Dakshina Kannada and Udupi districts of Karnataka State for the period between 1967 and 2005 studied by comparing the SOI topographic maps with IRS-1C/1D LISS-III satellite imageries through GIS techniques. Examination of coastal geomorphology, sediment flux and effectiveness of seawalls had indicated that the 130km long coastline of Dakshina Kannada and Udupi districts is essentially stable, but for seasonal variations. It has been estimated that, out of 130km, about 55km long coast is vulnerable to sea erosion, of which, 25km is covered byseawalls and covering another 10km length underway. It is revealed through field examination that protection of coastline through these measures is satisfactory only along few patches while other stretches of seawalls simply shift the zone of erosion to adjacent coastline owing to many reasons including quality of construction, unscientific positioning of seawalls, etc. It is also inferred that same is the case of many other coastlines elsewhere including Kerala coast. These experiences warrant scientific design and implementation of coastline protection measures.

INTRODUCTION

The 130km long coastal zone of Dakshina Kannada and Udupi districts is one of the densely populated coastal zones of India. The coastline is almost straight, regular and oriented towards N22°W, N12°W and N6°W directions at south of Mangalore, north of Mangalore and north of Malpe respectively. Barrier beaches and spits, ancient beach ridges, marshes, swamps and tidal flats characterize this zone. Natural features and man-made structures interrupt the shoreline. The natural features include estuarine mouths of Netravati-Gurpur rivers near Mangalore, Mulki-Pavanje rivers near Mulki, Udyavara river near Malpe, Sita-Swarna rivers near Barkur, Kollur-Chakra-Haladi rivers near Kundapur and rock exposures near Someshwar, Surathkal, Mulur, Kapu and north of Malpe (Fig. 1). The man-made structures include one major and four minor ports; breakwaters at the Netravati-Gurpur estuary, New Mangalore Port and Malpe harbor and a number of seawalls placed at various places along the coastline (Fig. 2). All these structures/features bring about local irregularity and contribute to erosion and accretion along the shoreline to some extent. Apart from these, source of beach material, coastal processes like wave refraction, longshore current, littoral drift etc.

Abstract

The area of study extends about 65 km from Gamasa City to Burg El-Burullus. The coastal sand dunes are very near to the shoreline in Baltim and El-Burg and far from the shoreline in Gamasa. It is narrow with relatively steep slope northward near Burg El-Burullus and Baltim, while it increases in width eastward to become wide with gentle slope near Gamasa. The coastal sand dunes are very mobile and move toward the agricultural lands, roads (international coastal road), resorts, and other developmental activities. The sand dunes in the study area are classified into two categories, the old fixed dunes and recent mobile dunes. The main directions of wind blow are N, W, and NW directions. It causes the movement of mobile dunes (Barchan and longitudinal). Several methods have been used for dune fixation like the tar spraying, wind fences and stones. Wind fences are not costly and nonpolluting if compared with stonewall and tar spraying, which prevent the land utilization for agricultural purposes.

Cocoa is popularly known as cacao in many cocoa growing nations. Cocoa beans are the source of commercial cocoa. The cocoa products viz., cocoa liquor, cocoa butter, cocoa cake, cocoa powder and cocoa chocolate are widely consumed across the World. Cocoa powder is essentially used as flavour in biscuits, ice cream, dairy drinks and cakes. Apart its use as flavour it is also used in the manufacture of coatings for confectioners or frozen desserts. Cocoa powder is also consumed by the beverage industry for example for the preparation of chocolate milk. Besides the traditional uses in chocolate manufacture and confectionery, cocoa butter is also used in the manufacture of tobacco products, soap and cosmetics. It is also a folk remedy for burns, cough, dry lips, fever, malaria, rheumatism, snakebite and wounds. It is reported to be antiseptic and diuretic. Looking at the industry needs for various purposes, there is a heavy demand for cocoa. At present, the gap between supply and demand in cocoa appears to be more at the national level. To fill the gap, various agro-technologies and crop improvement strategies are to be chalked out, for which the response of the crop to various environmental factors are to be understood. Weather aberrations during the flowering and fruiting result in the final cocoa production. Therefore, it is important to understand the effect of weather on flowering and fruiting pattern of cocoa to minimize the crop losses against the weather abnormalities. Though it is known that cocoa yield is highly variable and sensitive to various weather factors, the studies on crop weather relationships in cocoa and its response to climate change/variability are relatively scant

The Coconut palm, also known as the Cocos Nucifera L., is one of the most fascinating and beautiful palms in the world. The coconut is believed to have originated in southeast Asia (Indonesia, Malaysia, Philippines) or Micronesia. Coconut has been cultivated in India since ages and plays an important role in social, economic and cultural activities of the people. The palm is amenable to both plantation and homestead management and it can be either a major crop or a minor one in a homestead garden of mixed crops. While responding favourably to scientific management, the palm also tolerates negligent farming to a certain extent. Thus, it can adapt to the divergent farming situations and management practices that are prevalent in different agro-climatic regions. The coconut palm is usually found near the sea on sandy beaches where it can tolerate salt spray and brackish soils. It is also grown under different soil types such as loamy, laterite, coastal sandy, alluvial, clayey and reclaimed soils of the marshy low lands. The ideal soil conditions for better growth and performance of the
palm are proper drainage, good water holding capacity, and presence of water table within three metres and absence of rock or any hard substratum within two meters of the surface. The coconut palm can also grow well inland, within altitudinal limit of 600 m to 1000 m in the Tropics. It requires an equatorial climate with high humidity. A year-round warm and humid climate favours thegrowth of coconut. The palm does not withstand prolonged spells of extreme weather/climate variations under rain fed conditions. A welldistributed rainfall of 1300–2300 mm per annum is preferred. It is known as a coastal tree since it is grown along the Coasts and Islands and does not tolerate high diurnal temperature range, that is the difference between the maximum and minimum temperatures.

Arabica coffee is reported to have originated in the tropical rain forests in Ethiopian highlands while Robusta is a native of the humid tropical lowlands of Central Africa, probably, Uganda. The major coffee producing countries
across the World are distributed between 23°N and 23°S of the equator. Beyond these latitudinal limits, temperature becomes a major limiting factor as coffee plants are sensitive to extreme temperature regimes. Thus within
the latitudes, altitude becomes a major factor. In areas, nearer to the equator, coffee plants require higher altitudes when compared to farther north and south (6.1 plate). The world’s largest coffee producer is Brazil with around 30% of total world output of coffee. Columbia comes in second with around two thirds of Brazil’s production. India is the sixth largest (after Brazil, Columbia, Vietnam, Indonesia and Ethiopia) producer of coffee. Coffee is reportedly introduced into the Western Ghats regions of South India around 1600 AD. However, commercial cultivation of coffee was opened in South India with the British enterprise and investment during late 1820s. Coffee occupies an important position among the plantation crops in India. It is cultivated mainly in the traditional States of Karnataka, Kerala, Tamil Nadu and to some extent in non-traditional areas viz., Andhra Pradesh and Orissa as well as in North Eastern States viz., Assam, Manipur, Meghalaya, Mizoram, Tripura, Nagaland and Arunachal Pradesh. Coffee in India is unique. Almost all coffee plantation are grown under the shade of forest/planted trees, where as it is grown under open conditions in all the major producing countries viz., Brazil, Vietnam and Columbia.

Soil sample collection is the first and most important step for soil quality analysis. A soil sample collected with due care and proper procedure is essential for getting reliable result of the analysis. The sample should represent the field and for practical purposes, an area of about 0.5 hectare is considered as one sampling unit. In case of conspicuous variation observed in the field in terms of texture, colour, slope etc, separate samples should be collected from areas differing in these attributes. In other words, sample should be collected from an area in the field with similar characteristics as seen through normal visual observation. Sampling should thus be avoided from areas like near trees, permanent vegetations, manure pits, manure piles or recently fertilized fields.

Soil Sampling procedure

1. For a particular field unit, one composite soil sample is prepared out of the samples collected from 7-8 spots distributed across the field unit. The entire field is covered by moving in a zig-zag manner from each sampling spot.
2. For each sampling point or spot, scrapping off the surface litter such as grasses or crop residues is done. Then, a “V” shaped pit of 15-20 cm length and of equal width is made. Depth of sampling depends upon the requirement and on the type of crop. For field crops like paddy, wheat etc, samples are collected from 15 cm depth. From the “V” shaped pits, take outslice of ½ inch thickness from both sides of the exposed pit surfaces from top to bottom.
3. The soil samples so collected from the 7-8 points are mixed thoroughly by hand and then is reduced to about 500 g by quartering process. The quartering process consists of a procedure in which the entire soil mass is divided into four quarters; the two opposite ones are discarded and the remaining two are remixed. This process is repeated till about 500g soil is obtained.

Soil is analyzed to know the nature of soil, to classify and advocate to farmers about the peculiarities of the soils and how much of fertilizers should be applied for better crop production.

A composite soil, of course, can not be moved to into a laboratory. The value of the laboratory work depends upon care in sampling. Each soil sample needs to be a fair representative of the specific area or horizon worth sampling.

If the sample is to be a representative of an area, it is necessary to take large number of samples spread over the area, pool them and sub-sample it so as to get a sample of desired size. For soil survey work, samples are collected from a profile which is typical of the soil of the surrounding area.

Precise collection and processing of soil sample is the first and foremost step for carrying out any soil study, therefore it is essential to collect the coil sample very accurately keeping in view the variations in slope, colour and texture of the soil management aspects. Soil sampling should be avoided from non-representative sites like recently fertilized plots, bunds, channels, marshy tracts and spots near trees, wells, compost piles etc. It should be kept in mind that erroneous samples will never yield accurate result in spite of very improved method of analysis. The depth of sampling may vary according to the need of soil study and extent of rhizosphere. However, in general the sampling depth for field crops is the plough layer (0 - 15 cm) but it could be up to one meter or as per the purpose of the study. Soil samples in dry farming areas should be taken depth wise as the roots of the crops in this conditions reaches to deeper layers in search of water and nutrients.

Mainly two types of soil samples (disturbed and undisturbed) are used for determining the physical properties of soil. The disturbed soil samples are used for determination of particle size distribution, particle density, aggregation, column studies for diffusion-dispersion coefficients and soil-water diffusivity. Whereas, undisturbed (core) soil samples are used for the estimation of bulk density, porosity, retention and transmission characteristics of air and water.

Soil is a mass of large variability and thus its sampling is the most challenging problem for any soil analyst. Practically, soil sampling is a two step process which includes (i) collection of soil from homogeneous unit and (ii) processing which in turn includes drying, grinding, sieving, mixing, partitioning and storing.

1.1. Sources of Error in Soil Chemical Analysis

Different sources of error involved starting from soil sampling to chemical analysis of a sample can be divided into three main groups:

1. Sampling error : This error results from variability among the different samples drawn from same soil unit with respect to the objective of sampling.
2. Sub-sampling error : This error is due to variability introduced among sub samples of the same soil sample.
3. Analytical error : This error introduced due to variability from one chemical determination to another on same sub sample.

This chapter explains how representative soil samples should be collected, labelled, transported and prepared for analysis. It identifies essential sampling equipment, including spades, khurpis, augers, trays, sampling bags, markers and polythene sheets. The recommended procedure involves dividing land into uniform sampling units, collecting soil from several well-distributed locations and combining these portions into a composite sample. The chapter describes V-shaped sampling cuts, suitable sampling depths and sample reduction through quartering. It also lists the field information that should accompany each sample. Procedures for air-drying, grinding, sieving and mixing samples are presented, together with precautions for avoiding unusual areas and contamination.

Water colour is consequences of the plankton, humus, metal ions (iron and manganese), weeds and peat materials, presence in water. Iron oxides cause reddish color whereas Manganese oxides causes brown or brackish colour in water. Water colour of an aquatic body also indicates the density of planktons. Brownish colouration without any foul smell is an indication of good growth of zooplankton. Phytoplankton or algae are usually green in colour and these green alage in large quantities turn the green color of water. Water color suggests plankton or other aquatic life growth, clear and transparent colour of water indicates low and poor growth of plankton. Brownish green to greenish brown colour of water indicates well for aquaculture.
Principle
Natural waters colour comprising yellow-brownish in appearance. It has been observed that potassium chloroplatinate (K2PtCl2) tinted with small amounts of CoCl2 yield colours that are very much like the natural colours of water. 1 mg/L of Pt (K2PtCl6) produces a standard 1 unit of colour. The intensity of colour increases as pH rises. For this reason recording pH together with colour is advisable.

18.1 Introduction

The commercially available water quality simulation models with various dimensions (1D, 2D and 3D) and database software designed to quantify movement and concentration of contaminants in lakes, streams, estuaries, and marine environments. The following water quality models were described below (Table 18.1).

18.2 Environmental Fluid Dynamics Code

The Environmental Fluid Dynamics Code (EFDC) is a multifunctional surface water modeling system, which includes hydrodynamic, sediment-contaminant, and eutrophication components. It has been applied to over 100 water bodies including rivers, lakes, reservoirs, wetlands, estuaries, and coastal ocean regions in support of environmental assessment and management and regulatory requirements. IT is a state-of-the-art hydrodynamic model that can be used to simulate aquatic systems in one, two, and three dimensions. It has evolved over the past two decades to become one of the most widely used and technically defensible hydrodynamic models in the world. It uses stretched or sigma vertical coordinates and Cartesian or curvilinear, orthogonal horizontal coordinates to represent the physical characteristics of a waterbody. It solves three-dimensional, vertically hydrostatic, free surface, turbulent averaged equations of motion for a variable-density fluid. Dynamically-coupled transport equations for turbulent kinetic energy, turbulent length scale, salinity and temperature are also solved. The model allows for drying and wetting in shallow areas by a mass conservation scheme.

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.