eChapters

Introduction

GIS (Geographical Information System) based mapping takes cogence of three major geometrical dimensions, point, line and polygons and in GIS these three features correlate their relationship through a concept called Topology. Among the various applications where covariate processing requires specific attention, the landuse/ land cover and Digital Elevation Models/surfaces or terrains are the major area of interest. Use and processing of data for these covariates carries importance as accuracy of both these aspects would influence the derivatives extracted out of them further. For example, if landuse is improperly defined, the site for which planning is proposed may not sustain, similarly, point data/elevation data in case of DEMs would decide the exact topography of any landforms for their further utilization. For their use in GIS, while DEMs depend upon point data, the landuse/ land cover will be taken care by polygons. For the purpose of the study, we are going to discuss about these two covariates in the following paragraphs.

Generally, Covariate (covariable) (koh-vair-iãt) in statistics is defined as a continuous variable that is not part of the main experimental manipulation but has an effect on the dependent variable. In other words, as per ANCOVA (Analysis of covariance) definition: a covariate is a control variable.

2.1. The Physical environment
    Light
    Soil temperature
    Water dynamics

2.2. Chemical environment
    Production of phytotoxins

2.3. Biological environment
    Trophic dynamics
    Community structure
    Biodiversity

Climate, in general, is the totality of weather during a longer period and over wider area. Agro climate can be defined as the conditions and effects of varying weather parameters like solar radiation, rainfall etc., on crop growth and production.

Climatic classification is a method of arranging various data of climatic parameters to demarcate a country or region into homogenous zones i.e., places having similar conditions.

Introduction

It is estimated that about 16 per cent of total geographical area of India (329 m ha) has moisture index value below - 66.6% and is thus classified arid. This area is further classified into hot arid (36.8 m ha) and cold arid (15.2 m ha) regions (Ramakrishna et al., 2000). The hot arid region is characterized by extreme temperatures, low (<500 mm) and erratic rainfall, very high wind velocities, low humidity, high PET (>1800 mm) and frequent severe droughts which occur once in three years to alternate years in general. The soil moisture and soil temperature regimes are aridic and hyperthermic, respectively. The hot arid region exists in Rajasthan, Gujarat, Andhra Pradesh, Punjab, Haryana, Maharashtra, and Karnataka (Fig 1).

Introduction

In India, hot arid ecosystem covering an area of 31.7 million ha lies at north western part of the country and 62% of this area falls in western Rajasthan covering 12 districts i.e. Jodhpur, Jaisalmer, Jhunjhunu, Sikar, Hanumangarh, Sri Ganganagar, Bikaner, Barmer, Pali and Sirohi. The major landforms in arid western Rajasthan are dune and inter-dune plains having sandy to sandy-loam textured soils. Temperature remains high for most part of the year reaching up to 42-45°C during prolonged summer months (April to July), whereas annual rainfall is very low and highly sporadic (100-400 mm) mainly occurs during August and September. Annual potential evapotranspiration ranges from 1500-2000 mm. Loss of fertile top soil from denuded soil surface through wind erosion is frequent during summer months. The region is subjected to frequent occurrence of droughts, once in every three years, which further intensifies the process of desertification (Samra et al. 2006). Shorter growing period, sandy soils, very low available water capacity, inadequate nitrogen and phosphorus availability are the major constraints. Soils are prone to severe wind erosion, terrain deformation and nutrient depletion. The region is mostly mono cropped and double cropping is being practiced extensively in canal and tubes well command area. Extensive fallowing in the past even in very good rainfall years because of uneven undulating topography and severe windstorm are the cause of concern. Ground water is deep and is usually brackish, declining at alarming rate due to excessive withdrawal for irrigation and other purposes. The region, however, sustains on perennial vegetation of Prosopis cineraria, Tecomella undulata, arid shrubs and grasses, which are rich resources of fodder for animal because cropping is affected by vagaries of monsoon. During last two to three decades, a 2 to 3-fold increase in irrigated areas with cultivation of both kharif and rabi crops has been recorded and most of these increments are resulted through conversions from rainfed areas, grazing lands and sand dunes into irrigated areas.

Abstract

An unprecedented tsunami hit the Andaman and Nicobar Islands and the coasts of Andhra Pradesh, Tamil Nadu, Pondicherry and Kerala on the 26^th of December 2004. The loss of life and property, though wide spread in all these areas, was very severe in thickly populated low lying coasts, such as Nagapattinam in Tamil Nadu. Survey of India, in association with the Department of Science and Technology, Govt. of India, New Delhi has taken-up the task of carrying out post-tsunami Mapping of the entire east coast of Tamil Nadu using Digital aerial stereo images acquired immediately after the tsunami. The project aims to generate ortho-rectified photographs on 1: 8000 scale, which are to be used for preparing damage assessment maps of the affected coastal areas. This paper discusses various issues related to Control Surveying, Digital Photogrammetry and Large Scale feature extraction that are involved in the mapping process in general and its credibility for tsunami damage assessment in particular.

Keywords: Tsunami, Digital Photogrammetry, Tsunami damage assessment in India.

Concept and Definition

Desertification is a major problem in the drylands of India, affecting the way of life for its inhabitants. The problem is more severe in the arid lands in the northwestern part of the country. There have been a few numbers of definitions of the word “Desertification”. However for simplicity of its origin and meaning we would refer to two of the frequently used ones; (1) proposed in 1991 by UNEP: “Land degradation in arid, semi-arid and dry sub-humid areas resulting mainly from adverse human impact and (2) prepared for the Earth Summit at Rio, held in June 1992, for inclusion in Agenda 21, as “Land degradation in arid, semi-arid and dry sub-humid areas resulting from climatic variations and human activities. (Anonymous 1992).

Comparing two of these initial definitions, it would show that first one indicated desertification as a state of natural resources like soil and vegetation, mainly resulting from human activity while the second one included climate as a major cause. However, it reduced the emphasis of human activities as being the primary responsible factor and tried to link the possible impact of climate change on desertification. But the simplicity of the 1992 definition of desertification helped researchers to bring in sharp focus on the special environmental and socio-economic problems of the drylands.

So over the years, the key words that explains the term “desertification” has been changing or are being amended for specific purposes. This would at least mean that the problem of desertification is still debated world-wide, and its impact is not limited to some nations/regions as was presumed and discussed in first of UNCCD platforms. Therefore, as a precaution and combating this process, few catchy words like non-sustainable management, productivity, over-exploitation of natural resources, dryland livelihood, droughts are found to surround the word desertification. Earlier, some, people equated desertification with advancing boundaries of the existing desert and in India, examples of expansion / contraction of geographical boundary of Thar desert was a public debate among various researchers and planners. In the same time, some of the definitions tried to broaden its geographical scope so that greater populations suffering from adverse effects of land degradation would benefit out of various remedial measures.

The earth has two motions. (1) Rotation and (2) Revolution. The earth rotates about its axis (west to eastward) with a speed of 464 m/s or 1669 km/hr. Its angular speed of rotation is about 7.29 x 10^-5 radians/sec or 0.26244 radians per hour. This rotation causes day and night and diurnal variations of weather.

The rotating earth revolves round the sun in an elliptical orbit (with the sun at one of its Foci) with a speed (orbital speed) of about 1.073 x 10⁵ km/hr or 29770 m/s or 29.8 km/s. This revolution causes seasons. It has been stated earlier that the apparent path of the sun with respect to the celestial sphere is called ecliptic.

The Intergovernmental Panel on Climate Change (IPCC) in its fifth assessment report (AR5) stated that warming of the climate system is unequivocal and is more pronounced since the 1950s. The atmosphere and oceans warmed, the amounts of snow and ice have diminished, and rise in sea level is noticed. Each of the last three decades has been successively warmer at the earth’s surface than any preceding decade since 1850 and the globally averaged combined land and ocean surface temperature data show a warming of 0.85°C over the period 1880 to 2012. The recent years viz., 2015, 2016 and 2017 were the hottest years on record. The warming trend in India since 1961 has indicated an increase of 0.9°C, which is likely to impact many crops, negatively impacting food production. There are already evidences of negative impacts on yields of wheat and paddy in northern India due to increased temperature, water stress, and reduction in number of rainy days. Coastal agriculture has the onus of providing livelihood to nearly 20 % of Indian population. The water logging and coastal salinity are the major factors affecting the agricultural output from the regions.

Abstract

A large tsunami triggered due to a massive earthquake of 9.3M in the offshore of Sumatra on 26^th December 2004 created havoc in several countries of the Indian Ocean. The deadly tsunami waves lashed the towns adjoining the coastline of several countries including Indonesia, Thailand, Malaysia, India and Sri Lanka causing more than 1,50,000 deaths. The earthquake occurred along the plate boundary is marked by a subduction zone between the Indian plate and the Burmese micro plate. In Andhra Pradesh, six coastal Districts were affected and amongst them four south coastal districts experienced maximum damage. In the present study, Tuppalapalem (vagarru revenue village) of Vakadu mandal, Nellore District was selected as a case study for discussion in the article. The objective of the study was to make an inventory of the damages to the natural and physical resources, by preparing pre and post-tsunami maps on geomorphology, land use / land cover, tsunami inundation and finally the tsunami risk zonation map on 1:8,000 scale. In this process, water and soil samples of the affected regions were also collected and chemical analysis was carried out. The data on damages were collected using a specially formulated data sheet. High resolution IKONOS data of January 2000 and IRS data of January 2005 were used for the generation of respectively the pre and post-tsunami geomorphology and land use / land cover maps. Ground truth data were also incorporated in these thematic maps.

The study has revealed that the water in all the bore wells became brackish after tsunami. About 80 country boats, 40 fibre boats and nets were lost with an estimated loss of about one crore. The tidal waters damaged the bunds of the aqua-farms and deposited the transported sediments in them. The extensive casuarina plantations, were reduced by the onslaught of tsunami and the casuarina trees became brown due to their contact with tidal waters. From amongst the various geomorphic units mapped in the study area, the beach, spits, shoals, creeks, swales, palaeo creeks were inundated by tsunami where as beach ridges, dune complexes and stabilized sand dunes were not affected and hence inferred as barriers. Geomorphology, land use / land cover and the tsunami inundation maps, tsunami risk zonation map were prepared showing very high, high and moderate zones of tsunami risks. It is recommended to take up casuarina plantations extensively along the coast as a biowall, which will also provide employment to the local people. The shallow aquifers of the coastal environment were contaminated by the tidal waves. Hence, drinking water should be supplied through protected water supply schemes. As a part of the community development, proper awareness must be created through training and appraisal to the fisherman community to face such natural disasters. The coastal regulation zone act, which prohibits any construction activity within 500m of the high tide line, should be strictly enforced. Keeping in view of the experience, a holistic tsunami protection plan is needed to safe guard the Indian coasts.

Tamil Nadu has unique physiography with western and eastern Ghats on the west and northwest, Bay of Bengal in the east and Indian Ocean to the south. Tamil Nadu has high dependence on natural resources and hence faces the threat of climate change and its impacts. Available evidence shows that there is high probability of increase in the frequency and intensity of climate related natural hazards (Stephen, 2012). Out of 13 million hectares of geographical area, about 7 million hectares of land is under cultivation. Of this 55 per cent is irrigated and rest is under rain fed / dry lands. In Tamil Nadu, ground water has been harnessed fully and dry land productivity is found oscillating with ruling variability in seasonal monsoon rain and hence agricultural productivity is always under stake.

10.1 Introduction

Biomass fuels are a potential source of renewable energy. One of the major barriers to their widespread use is that biomass has a lower energy content than traditional fossils fuels, which means that more fuel is required to get the same amount of energy. When combined — low energy content with low density -the volume of biomass handled increases enormously. Compaction or densification is one way to increase the energy density and overcome handling difficulties.

Densification means compaction of loose material or to increase density of loose biomass so that its volumetric efficiency can be increased. Densification essentially involves two parts; the compaction under pressure of loose material to reduce its volume and to agglomerate the material so that the product remains in the compressed state. The resulting solid may be a briquette, a pellet and a cube. It will be briquettes if roughly, it has a diameter greater than 30 mm. Smaller sizes are normally termed pellets though the distinction is arbitrary. The process of producing pellets is also different from the typical briquetting processes. The densified product can be developed in the cubical shapes as well.

If the material is compacted with low to moderate pressure (0.2-5 MPa), then the space between particles is reduced. Further, increasing the pressure will, at a certain stage particular to each material, collapse the cell walls of the cellulose constituent, thus approaching the physical, or dry mass and more, density of the material. The pressure required to achieve such high densities are typically 100 MPa plus. This process of compaction is entirely depending on to the pressure exerted on the material and its physical characteristics including its moisture content.

Introduction  

Developing effective strategies for improving and stabilizing rainfed crop production continues to be a prime concern in the semi-arid region of western India. Rain water management is most crucial aspect in rainfed production systems. Growing uncertainties associated with rainfall pattern (Ali et al., 2007) add to the complexity of the challenge. The medium deep black soil region of Rajasthan is spread predominantly in Jhalawar, Kota, Baran, Bundi, and Sawai Madhopur districts of South-eastern Rajasthan (Fig. 1). This region is characterized by almost flat alluvial plains interspersed with hills of Arawali and Vindhyan ranges and rock outcrops. 

Climatic Factors and Crop Growth

Crop growth depends on internal and external factors. Internal factors are mostly genetic or hereditary factors which include high yielding ability, resistance to lodging, tolerance to adverse conditions such as drought, flood and salinity, tolerance to insect pests and diseases, and grain quality. The external factors include climate, edaphic, biotic, physiographic and socio-economic factors.

The coastal agro ecosystem is very important among the different agro ecosystems of our country both economically and environmentally. It spans over a length of 8129 sq. km. covering 9 states and 2 Island ecosystems. Agriculture and allied activities constitute the single largest component of India’s economy, contributing nearly 27 per cent of the total Gross Domestic Product (GDP) in the year 1999-2000 (TERI, 2002). Agriculture exports accounts for 13 to 18 per cent of total annual exports of the country (MoF, 2002). However, given that 62 per cent of the cropped area is still dependent on rainfall (MoEF, 2002). Coastal agricultural region comprises of hinterland, which has a varied geometric and topographical features of mountains valley, coastal plains, riverine systems, climatic conditions, different soils and water bodies, vegetation ranging from rich tropical rain forests to coastal mangroves and a wide range of crops that are cultivated in this region (Table 1). The agro climatic conditions of the coastal zones are congenial for growing various field and horticultural crops.

Introduction

Soil is considered one of the world’s limited, non-renewable resources. Under cropland conditions, it takes between 200 and 1000 years for 2.5cm of topsoil to form (Piementel et al., 1995). The continued maintenance of fertile soil is essential in order to meet basic human needs. It strengthens the provision of ecosystem services such as food production and climate regulation, and provides the basis of livelihoods for millions of people across the world (Ma, 2005). The multi-functionality of soils is key to the sustainable use of land and soils. A healthy soil performs six essential functions (Andrews et al., 2004) namely: i) Physical Stability and Support, ii) Water Relations, iii) Resistance and resilience- iv) Nutrient Cycling, v) Biodiversity and Habitat and vi) Filtering and Buffering. These soil functions are controlled by various soil properties. Among them soil structure is one of the most important properties of soil, which describes soil condition and has a great influence on crop production.

1. Introduction
Bioremediation is an environmentally friendly process that uses numerousdifferent microbes (e.g., fungi & bacteria), green plants, or combinations
of them to weaken and detoxify dangerous pollutants in a sequential orsuccessional manner. The pollutant composites are converted by biologicalorganisms through a response that takes place as part of their metabolicprocesses. They convert poisonous pollutants into carbon dioxide (CO2) andwater (H2O), microbial biomass, and other products that are less poisonous.The organic wastes are biologically degraded under controlled, harmless, andsafe condition into inoffensive products below the admissible limits establishedby supervisory authorities.

Introduction

Climate change has undoubtedly resulted in greater public and scientific involvement. Climate change refers to any change in climate over time, whether due to natural variability or as a result of human activity (IPCC, 2007). The United Nations Framework Convention on Climate Change (UNFCC) defined it as a change of climate that is attributed directly or indirectly to human activity which alters the composition of the global atmosphere and that is in addition to natural climate variability observed over comparable time periods. World Meteorology Organisation defines climate change as statistically significant variation in either the mean state of the climate or in its variability, persisting for an extended period (typically decades or longer). 

Agriculture and Food Security

Food security refers to a situation when people gain physical and access to enough food to meet the dietary requirements for a healthy life for all times. A household can have food security when all the members lead a hunger free life. It is estimated that nearly 800 million people in the world go to bed hungry every night. Food security exists when all people, at all times, have physical and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life (World Food Summit, 1996). This definition gives rise to four dimensions of food security: availability of food, accessibility (economically and physically), utilization (the way it is used and assimilated by the human body) and stability of these three dimensions.

INTRODUCTION

The discipline of Agrometeorology, an applied science is less than fifty years old. Its services are operationally used by individual farmers in developed countries, and by agricultural or development services in more than half of the countries of the world. Its contribution to agricultural production by examining forecast is sought in virtually all countries. In many countries, the respective governments have expressed the desire to use meteorological information to a much larger extent in day-to-day farm planning and operations. The climate database is used for the development of practical criteria in planning and management of irrigated and rainfed crop production system (Martin Smith, 2000).

Though a huge set of Agromet data exists in India, its utility has not been effective due to the scattered location of these data sources and the impediments for free flow of data to the users to analyze and interpret for real-time decision making in agriculture. There is also a considerable time lag between the actual observation and data availability. In view of the importance and the immediate exigency to centralize the database system for helping the researchers and planners, a central agrometeorological databank facility funded by DST from 1998 to 2003 and later by ICAR with the following objectives was established at Central Research Institute for Dryland Agriculture (ICAR), Hyderabad.