eChapters

Importance

Drought is a climatic anomaly characterized by deficient supply of moisture, which may result from sub-normal, untimely and unevenly distributed rainfall. Among the various hazards of nature, drought is one of the major disasters because it brings innumerable miseries to the mankind. Almost every year some part or the other of the country suffers from such calamities. Drought is a recurring phenomena and its occurrence cannot be avoided. However, its impact can be minimized through application of science and technology by developing drought management plans.

The world’s drylands include hyper-arid, arid, semi-arid and dry sub-humid areas where rainfall is highly scanty and variable. Droughts are common in areas / zones where water is the principal limiting factor for agriculture (https:// www.fao.org/3/t0122e/t0122e03.htm) . Dryland soils are characterized by low levels of moisture, organic matter, and biological activity, consequently such soils are very poor in fertility devoid of plant nutrients. When, these soils suffer further degradation in fertility, resulting in erosion, desertification, and salinization when crops are grown on such soils inappropriately without any scientific basis. However, the major factor limiting agricultural production on drylands is the lack of adequate moisture for crop growth or drought.

Introduction

Drought is defined as “when a region receives below average precipitation,  resulting in prolonged shortages in its water supply, whether surface  or ground water or atmospheric. It can have a substantial impact on the  ecosystem and agriculture of the affected region.” When drought arises in  a particular area, obviously it affects the crop and livestock production. In  order to reduce the effect of drought on farm productivity and to stabilize farm  income, farmers have to take some systematic measures, and such measures  are referred to as drought coping mechanisms. The objective of the study was  to identify the determinants of the adoption of drought-coping mechanisms to  balance and stabilize the farm income of the stakeholders. The study also helps  to know how to mitigate the effect of drought on farmer’s livelihoods.

The existing literature on the adoption of drought coping mechanisms is  quite meager. Akwango et al., (2016), Chandan Kumar Jha et al., (2017),  Emmanuella Ellis (2017), Ronald Twongyirwe et al., (2019) assessed the adoption strategies by considering multinomial logistic regression and the  results state that the use of different tree planting, crop varieties, soil and water  conservation, early and late planting, and furrow irrigation. The data related to  the adoption of any agriculture technology have qualitative response variables  with two or more categories. Most of the studies used qualitative response  models such as the logit model, probit model, and multivariate techniques like  discriminant analysis to measure the farmer’s perception toward the adoption  of any agriculture technology. In this study, we chose machine learning models  such as Decision tree, to assess the classification ability and to determine the  factors influencing adoption.

5.1 Introduction

Out of the many climatic events that influence the earth’s environmental fabric, drought is perhaps the one that is most linked with desertification. Drought is a natural hazard originating from a deficiency of precipitation that results in a water shortage for some activities or some groups and is often associated with other climatic factors (such as high temperatures, high winds and low relative humidity) that can aggravate the severity of the event. Drought differs from aridity in that the latter is restricted to low rainfall regions and is a permanent feature of the climate. Drought occurrences are common in virtually all climatic regimes.

Widespread and severe drought conditions in Asia, Latin America and the Caribbean in 2000 have raised serious concerns about the continuing vulnerability of the world community to extended periods of droughts and water shortages. In 2000, major droughts affected much of south-eastern Europe, the Middle East, and the area through central Asia to northern China. Especially hard hit was Afghanistan, Bulgaria, Iraq and the Islamic Republic of Iran and parts of China. In North America, months of above-average temperature coincided with below-normal precipitation through northern Mexico and much of the southern and western regions of the USA, leading to one of the worst wildfires in the past 50 years.

By August 2001, much of Western Asia, Central Asia, and the Middle East was suffering the third year of a continuing drought that severely reduced many countries’ crop yields. The countries most affected were Afghanistan, India, Islamic Republic of Iran, Pakistan, and Tajikistan.

1. Introduction
Drought’ which apparently means lack of water, is one of most vulnerable natural hazards. It alone causes a huge crop loss annually. But history says it not only affects crop but destroys human lives.in the year 1972 almost 600000 people died due to starvation caused by huge drought in Northern India. In simple language drought means shortage of water mainly caused by abnormal climatic condition and damaging to the environment. Ideally there is no such proper definition of drought because it should be region specific and circumstances specific. A per McMahon and Diaz Arenas (1982) define drought as “a period of abnormally dry weather sufficiently prolonged for the lack of precipitation to cause a serious hydrological imbalance, carrying connotations of a moisture deficiency with respect to man’s usage of water”. Apart from these several general definitions have been provided by many authors. Beran and Rodier (1985) gave a definition based on hydrological aspect of drought that, ‘The chief characteristic of a drought is a decrease of water availability in a particular period and over a particular area’. India meteorological department (IMD) has defined drought as a situation in a subdivision in a year when the actual rainfall is less than 75% of the normal annual rainfall. Basically, to define drought the impact on environment and society and their complex interaction must be considered. Drought is defined as a state of total water capacity being within the range of 12-20% for a period of 16 days and can be distinguished from water deficit, which is the state of water capacity falling below 30%. Drought affects crop development, production, productivity and quality and on other hand soil physical, chemical and biological properties.
2. Classification of Drought
As per the hydrological point of view drought can be classified into different Categories: i) On the basis of source from which water is available: -a. Meteorological Drought b. Hydrological drought c. Agricultural Drought. ii) On the basis of time of occurrence: - a. permanent drought area b. Seasonal Drought Area contingent drought. iii) On the basis of medium: - a. soil drought atmospheric drought.

Drought, a recurring and often devastating feature of climate variability, presents a unique challenge due to its slow onset, complex nature, and farreaching consequences. Unlike hazards with clear event boundaries, drought manifests across diverse spatial and temporal scales and impacts nearly every facet of the environment and human activity. Effectively understanding and managing this phenomenon necessitates an equally comprehensive approach: drought monitoring. This chapter introduces the essential concepts and methodologies underpinning this critical field, highlighting the remarkable breadth required to capture the full picture of drought conditions. • The scope of drought monitoring is inherently vast. Geographically, it spans from tracking localized water stress affecting a single farm or watershed to assessing conditions across entire regions, nations, and continents. Temporally, monitoring efforts must consider short-term deficits unfolding over weeks or months (critical for agriculture) as well as long-term hydrological imbalances developing over seasons, years, or even decades (impacting reservoirs and groundwater). Understanding current conditions crucially relies on comparing them against a deep historical context, requiring decades of baseline data

Drought is a complex and multifaceted issue that affects various aspects of the environment, economy, and society. Its far-reaching consequences underscore the need for a comprehensive and collective approach to mitigate its impacts. 2.1 Drought Prone Area Delineation Drought-prone area delineation involves using scientific criteria like low and erratic rainfall, groundwater potential and agricultural indicators to identify regions susceptible to drought. Modern methods use GIS (Geographic Information Systems) to integrate data from satellite imagery, weather patterns, soil conditions, and vegetation to precisely map drought-vulnerable zones. This spatial analysis allows for targeted interventions such as improved water management techniques and sustainable agricultural practices in the most affected areas. Here are some additional details on the universal nature of drought and the benefits of a global response:

Introduction

Drought is the most common adverse environmental factor which limits crop production in different parts of the world. Often drought is accompanied by relatively high temperatures, which promote evapotranspiration, and hence could accentuate the effects of drought and thereby further reduce crop yields. Since these events occur more frequently in tropical and semitropical regions where most of the developing countries are situated, droughts are often associated with food shortages and an overall setback to developmental activities. Therefore, raising of drought-resistant crops is common sense to achieve stability in production and to enhance the possibility of self-suficiency in food. Consequently, breeding for drought resistance is a major objective of many research programmes in the international and national institutions. This has been so for the past several decades. But, it is disappointing that, there has not been any measurable success in these programmes compared with the success achieved in breeding for yield; or breeding for disease resistance or breeding for quality attributes. In fact, this was amply expressed by Arnon (1980) when he stated “Breeding for drought resistance has been a consistent theme for as long as I remember and probably the greatest source of wasted breeding efforts in the whole field of plant breeding.” However, the fact remains that we do hear of drought resistant varieties in many crops. For example, C-306 in wheat, Lalnakanda in rice and M 35-1 in Sorghum are some of the better known examples in India. It is also claimed that a large number of cultures among the Assam Rice Collection exhibit a considerably high degree of drought tolerance. Many land races and wild relatives of several crop species are said to contain drought resistant traits, which could be profitably utilised in breeding programmes. This situation is not unique to India alone but is a common experience in different parts of the world. However, to afirm a conviction a short questionnaire to assess the current state-of-art on breeding for drought resistance was distributed to 75 distinguished plant breeders and plant physiologists all over the world. The questionnaire and a summary based on the responses is as follows:

Drought Early Warning Systems (DEWS) form the essential foundation for effective and proactive drought management strategies. These systems are crucial in facilitating a fundamental shift from reactive approaches, where responses are implemented after the onset of a crisis, to proactive risk reduction measures that aim to anticipate and mitigate the adverse effects of drought before they fully materialize. By providing timely and accurate information about impending drought conditions, DEWS empower governments, communities, and individuals to make informed decisions and take preemptive actions, thereby minimizing the potential economic, social, and ecosystem losses associated with these events (Fig.6.1). Recognizing the risks posed by drought in a timely manner is of paramount importance for ensuring an effective and comprehensive response that can alleviate suffering and reduce overall vulnerability. The implementation of robust drought early warning systems plays a critical role in minimizing the negative consequences of drought and building longterm resilience to this recurring natural hazard.

Imagine the lifeblood of a nation’s energy grid thinning to a trickle. This is the stark reality when prolonged droughts grip regions heavily reliant on the oncemighty force of hydroelectric power. While the allure of clean, renewable energy from flowing water has positioned hydropower as a cornerstone of electricity generation globally, its dependence on a consistent and abundant water supply renders it exceptionally vulnerable to the increasingly frequent and intense droughts sweeping the planet. This chapter embarks on a critical exploration of the intricate and often strained relationship between these two forces: the essential need for water in sustaining hydroelectric power and the devastating impact of its absence during drought conditions Moving beyond a simple definition, we will delve into the multifaceted ways in which droughts cripple hydroelectric facilities, from dwindling reservoir levels that starve turbines to the cascading effects on energy security, economic stability, and ecological balance. We will traverse the globe, examining compelling case studies from drought-stricken regions, revealing the tangible consequences for communities and industries. Furthermore, this chapter will unpack the complex interplay of factors that exacerbate

Drought, characterized by prolonged periods of abnormally low rainfall, is a recurring and devastating natural phenomenon with profound implications for global agriculture. Among the sectors most vulnerable to the adverse impacts of drought is livestock production. This chapter, “Droughts and Livestock Production,” delves into the intricate relationship between these two critical elements, exploring the multifaceted challenges and consequences that drought poses to livestock farming across diverse geographical contexts The chapter will examine how water scarcity, a hallmark of drought, disrupts the delicate balance of feed availability, animal health, and overall productivity within livestock systems. It will further analyze the varied impacts of drought on different livestock species, considering their unique physiological needs and vulnerabilities. Beyond the immediate 

The 21st century has ushered in an era of unprecedented drought challenges, with far-reaching implications for global ecosystems, economies, and human societies. The increased frequency, severity, and duration of droughts worldwide have pushed water resources, agricultural systems, and communities to the brink, underscoring the pressing need for comprehensive understanding and proactive management. • One of the most striking aspects of modern droughts is their capacity to affect vast geographic areas, transcending national borders and impacting multiple sectors simultaneously. The 2012 drought in the United States, for instance, affected over 80% of the country, leading to significant economic losses in agriculture and beyond. Similarly, the 2018 Cape Town water crisis brought the city to the edge of “Day Zero,” where the taps would run dry, highlighting the devastating potential of droughts on urban water systems. • The impacts of droug

Introduction
India is the seventh largest having 329.73 million ha of geographical area and second most populous country having more than a billion population in the world. There is no other substitute other than to use every square inch of land and every drop of water effectively and efficiently. Though there was markedly increase in annual food grain production from 51 (1950-51) million tones t0 206 million tones (2000-01), still the death on hunger is visualized.
The demand for food is increasing with ever-increasing population growth rate. So there is no option other than to increase food production. There is very little or no scope of horizontal expansion due to land limitation, the question of vertical expansion is the only way to fit with the situation. Genetically improved crop variety, hybrids, mechanized agriculture, higher rate of fertilizers and chemicals application may give one or two more green revolution, but the question lies how far it can sustain greenness?
Adoption of improved crop cultivars, cropping system, increasing cropping intensities, precision farming can hold good to get out of this situation where whole system is to be considered.
The cropping intensities in the states like Assam, Bihar, MP, Orissa, UP and West Bengal are 137.7, 137.8, 125.6, 154.6, 148.6 and 159.6 percent, respectively (FAI,1994-95). This indicated that a vast majority of lands remain fallow during dry season due to lack of proper technologies, which are under rainfed conditions, neglected. Except West Bengal, more than half of the arable land remains fallow during rainless period. Increasing cropping intensities in rainfed uplands is not easily achievable but there is great potential of intensification of cropping in rainfed lowland by utilizing natural resources and conserved residual moisture. Pulses like black gram, green gram, lentil, lathyrus, chick pea and oilseeds like linseed, groundnut, rapeseed could not only increase the cropping intensities but also come forward to increase national productivity.

Introduction

Agroforestry being old as an art and new in its scientific terms has been gaining importance in the modern era due to shift of world from technology to nature in search of resilient way of sustaining livelihood (Dutta et al., 2023, Sharma et al., 2023 Bishaw et al., 2022, Agnoletti et al., 2022). The simplicity of the agroforestry system is the flagship reason of its widespread applicability and reliability in agricultural domains. There has been change in the world perspective regarding the nature and natural resources in recent times. Although there has been forest over 31 per cent of the world’s total geographical area (FAO and UNEP, 2022) but the stabilization of ecosystem and sustainable development is difficult without subsequent interaction between the tree, crop and livestock component on farm lands, being collectively called as agroforestry.

Plant diseases significantly reduce crop productivity, quality, and economic returns, making early and accurate detection essential for effective crop protection. This chapter examines the application of machine learning and computer vision for identifying diseases at an early stage. It discusses agricultural image acquisition using RGB, hyperspectral, and sensor-based technologies, followed by image preprocessing, segmentation, feature extraction, and classification. Machine learning algorithms such as support vector machines, random forests, and convolutional neural networks are considered for disease recognition. The chapter also explores the integration of AI with IoT and mobile technologies and presents practical applications while addressing challenges involving datasets, environmental variability, model generalization, and computational requirements.

1.1. What is Earth?

The Earth is a layered body consisting of three parts: core, mantle, and crust. The radius of the Earth is nearly 6370 km of which crust, mantle and core share a depth of 40, 2850 and 3480 km, respectively (Figure 1.1). Exterior of the Earth contains the outer lithosphere which is surrounded (70% of surface) by water (hydrosphere). Solid and liquid sphere are surrounded by gas (atmosphere). The atmosphere is of 320 km above the lithosphere / hydrosphere. It is believed that there is a progressive increase in temperature with depth, if one goes to the core from the Earth crust. There is a rise of approximately about 1°F for every 64 feet depth on an average. Therefore, one could imagine that the interior of the earth is in molten condition.

An earthen dam is an embankment constructed primarily from compacted soil to impound runoff and create a reservoir. Such dams support irrigation, water supply, groundwater recharge, hydropower generation, and flood moderation. Their successful performance depends on suitable site conditions, proper materials, adequate compaction, controlled seepage, stable slopes, and safe disposal of surplus water. This chapter introduces the advantages and limitations of earthen dams, construction materials, types of embankment sections, and their principal components. Particular attention is given to cut-offs, impervious cores, casing or shells, foundations, filters, drainage systems, spillways, outlets, slope protection, and common causes of deterioration or structural failure.

6.1 Introduction

Urbanization is now a global phenomenon, but in developing countries the implications are more pronounced. Natural growth of population, reclassifications of habitation and migration trends are important in urban population in India. The population of India, which accounts for 27 per cent of the total population, was 285 million according to 2001 census. International experience shows that the pace of urban development accelerates when a country’s urban population crosses close to 25 percent of the total population (like in India).(Kumar and Chakrabarti, 2010). 

11.1 Introduction

Economic analysis is the most important parameter for determining the optimum size of farm pond. It is, no doubt that a big size farm pond can meet the irrigation demand of the crops grown in the command areas in addition to meeting the other demand in the command areas. But a big size farm pond is an oversize structure which necessitates large investment to be incurred which may not be economically viable. On the other hand, a small size structure may not be able to meet the crop water demand and also other demands in the command areas and so is called as under-designed structure. It has been observed that as the size of the farm pond gradually increases from a certain minimum size, the total investment cost increases. At the same time, the benefits from the increasing storage capacity of the farm pond also get increased. In such cases, from a purely business point of view, the most economical capacity is that which provides the highest rate of return on investment. As the size of the farm pond increases, the proportion of the benefit/profit to the cost also increases from certain minimum size, attains maximum value at a particular size and then declines as the size further increases. This particular size of the farm pond at which the net profit is maximum, is called as the optimum size. It is to be noted that at the optimum size, the other economic indicators like the benefit-cost ratio and internal rate of return are also high. The variation of net profit with size of the farm pond is a concave curve. The size of the farm pond corresponding to the peak of the curve which represents the highest net profit is the optimum size of the pond.

The principle of obtaining the optimum size of farm pond is to first assume a certain minimum size say five percent of the farm area and conduct the economic analysis by studying the costs and net profits of the assumed size. Then the size is gradually increased and the economic analysis is conducted for each increased size. Then a curve relating the size of the farm pond and net profit is drawn. Such a curve is generally concave shaped. The size of the structure corresponding to the maximum net profit gives the optimum size. It is to be noted that any size chosen more or less than the optimum size would give less net profit and benefit-cost ratio than that of the optimum size.

About two-thirds of the developing world’s three billion rural people live in about 475 million small farm households, working on land plots smaller than two hectares. Many are poor and food insecure and have limited access to markets and services. Their choices are constrained, but they cultivate their land and produce food for a substantial proportion of the world’s population. Besides farming, they have multiple economic activities, often in the informal economy, to contribute towards their small incomes. These small farms depend predominantly on family labour. In China, nearly 98 percent of farmers cultivate farms smaller than 2 hectares – the country alone accounts for almost half the world’s small farms. In India about 80 to 85 percent of farmers are small. In Ethiopia and Egypt, farms smaller than 2 hectares constitute nearly 90 percent of the total number of farms. In Mexico, 50 percent of the farmers are small; in Brazil smallholders make up for 20 percent of the total number of farmers (Rapsomanikis, 2019).