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Drainage - definition

Agricultural drainage is the artificial removal and safe disposal of excess water either from the land surface or soil profile, more specifically, the removal and safe disposal of excess gravitational water from the crop root zone to create favourable conditions for crop growth to enhance agricultural production.

Benefits of drainage

a)It provides better soil environment for plant growth by creating favourable soil aeration conditions.

b)It improves the soil structure and in turn increases the soil infiltration.

c)High infiltration capacity reduces soil erosion.

d)It hastens the warming of the soils and maintains desirable soil temperature, which accelerates plant growth and bacterial activity.

e)It promotes increased leaching of salts and prevents accumulation of salts in the crop root zone.

f)In well drained soils, less time and less labour are required for tillage operations.

Technical Term      Definition

Drainage               Removal and disposal of excess water from agricultural lands is referred as drainage.

SUMMARY

The natural drainage systems are severely affected by the development processes and thus increased in waterlogged and salt affected areas. In major and medium irrigation projects due to inadequate designs coupled with poor management practices has raised groundwater table and in turn sizeable command areas are being affected both by water logging and soil salinization, Water logging and salt problem have been experienced in irrigation projects all over the country. Both adversely affect the growth and the yield of the crops. An area with water table within 2 m from the land surface is called as water logged area. It is potential to water logging if water table is between 2-3 m from the land surface. It has been estimated that around 16.71 million hectare land is affected by salt and waterlogging in India. The drainage is the remedy to these problems for sustainable agriculture.

            Drainage is defined as the natural or artificial removal of surplus ground- and surface water and dissolved salt from the land in order to enhance agriculture production. In the case of natural drainage the excess waters flows from the fields to lakes, swamps, streams and rivers. However, in an artificial system surplus ground or surface water is removed by means of sub surface or surface conduits. Improved drainage create a healthier environment for plant growth, It conserve soil and water; and provide drier field conditions for ease in farm operations for the crop production. Agricultural drainage is must to realize the full benefit of irrigation.

Agricultural land drainage is adopted for removal of excess surface and subsurface water, either from irrigation or rainfall in order to improve the profitability of land use.  Drainage also plays a role in removal of salts from the root zone. Therefore, land drainage is closely linked to irrigation in arid and semi arid regions. India has a long history of practicing irrigation and drainage in its semi arid irrigated regions. During the ancient times in the Indus Valley dams and drainage system were built for cultivation of different crops. The earlier experience of drainage was more concerned with surface drainage because from time immemorial India has been experiencing floods of varying magnitudes.

Introduction

In the process of creating a hole in the metal surface through a drill, we use a drilling machine. We use a tapper shank and parallel shank to tie the drill to the drill machine. We can also use a drilling machine to do extra experiments i.e., tapping rimming counter shrinking and counterboring. In simple language, we also say that a, it is a machine which is wildly used over world for making a circular hole in various metal workpiece for making desired design or structure.

Crop Water Requirements

In designing an irrigation system, the primary objective is to know the water requirement of crops. Water requirement of crops are determined either by f ield cultivation or by estimation through commonly used empirical formulae such as Blaney Criddle, radiation, Penman or pan evaporation method.

Definitions

Crop water requirement or evapotranspiration (ETcrop ): It may be defined as the rate of evapotranspiration of a disease free crop growing in a field of not less than one hectare under adequate fertility and water supply so that full productive potential can be achieved in prevailing environment. Evapotranspiration requirement of a crop refers the ETcrop and expressed in mm/day.

Reference crop evapotranspiration (ET0 ): It is the rate of evapotranspiration from an extended surface of 8 to 15cm tall green grass of uniform height, actively growing, completely shading the ground and not short of water. ET0 may be computed by using the empirical formulae and meteorological data for the specific period.

Introduction

Drip irrigation is an efficient method of application of water at the plant bottom at a rate nearly equal to the consumptive use rate of the plant, thereby minimizing the conventional water losses like percolation, runoff and evaporation from soil. It is a process of slow application of water on, above or beneath the soil by the surface, sub-surface, bubbler, and spray or pulse system. Fertilizer can also be applied with the drip water. Emitters or applicators are placed closed to the plants and used to spray water in the form of drops, tiny streams or miniature spray. In the drip system water applied from the point source advances in all direction in the soil outward from the source. Drip irrigation is essentially a low rate, low pressure, frequent and long duration application of water in plants root zone area.

Drip irrigation is also called as localized irrigation, trickle irrigation, daily f low irrigation, diurnal irrigation, drop irrigation, sip irrigation, and micro irrigation. A particular name is being popularized in any area depending on the choice of the people of that area. The International Commission for Irrigation and Drainage (ICID) has recommended the term micro-irrigation while the American Society of Agricultural Engineers (ASAE) has preferred drip irrigation. In India it is told as drip irrigation.

Aerial photography is objective of getting panoramic view of earth surface to analyze the features of earth and their interrelation at particular time period which may be changed in further events. In this concerned, the observation may play a vital role in achieving the goals of photography. Undoubtedly it is widely used in social function and so on, but still awaited for scientific or research use. Drone can measure the geometry of ground surface at lower altitude with more accuracy in the form of visual feature in natural colour. flight height of drone mainly limits the large area coverage due to lower flying and drone can work perfectly at low altitude planning with good quality feature/photography.

OVERVIEW OF UNMANNED AERIAL VEHICLE (UAV) TECHNOLOGY
Agricultural drone technology employs drones equipped with cameras and sensors to assist farmers in monitoring crops, applying pesticides, and analyzing soil conditions. This technology assists farmers in making informed decisions, enhancing yields, and minimizing chemical application.
A drone is fundamentally a flying robot that can be operated remotely or autonomously through software-driven flight plans within its embedded systems, which integrate with onboard sensors and a Global Positioning System (GPS).
Drones are remotely operated or autonomous aircraft engineered to function without a pilot on board. They are also referred to as Unmanned Aerial Vehicles (UAVs). They has the capability to function alone or be managed by human operators.
• They have gained significant popularity in recent years owing to their extensive range of applications and uses. Drones are available in a range of sizes and configurations, from compact portable models to larger variants. They possess an array of equipment that enables optimal functionality.
• The fundamental components of a drone consist of motors, propellers, flight controllers, batteries, and remote control systems. The motor and propeller are essential for generating push to elevate the drone from the ground, whilst the flight controller functions as the drone’s brain, responsible for data processing and movement regulation.
• The battery energizes the drone’s electronic components, while the remote control systems enable the operator to maneuver the drone. The drone functions by an integration of electronic components and software algorithms.

Agricultural drones have emerged as important tools for precision farming, crop surveillance, and field-level data acquisition. This chapter introduces drones as aerial intelligence platforms capable of collecting high-resolution spatial and spectral information about crops, soil, and environmental conditions. It discusses drone architecture, sensing technologies, remote sensing, crop monitoring workflows, and crop health assessment. Artificial intelligence and machine learning enable efficient analysis of aerial imagery for disease detection, irrigation management, precision spraying, crop stress assessment, and yield prediction. The chapter also examines autonomous drones, drone swarms, IoT integration, edge computing, and digital twins. Operational limitations, regulatory considerations, data management, and sustainability implications are also addressed.

Drought

There is no universally accepted definition of drought. Early workers defined drought as prolonged period without rainfall. Drought is a situation when the actual seasonal rainfall is deficient by more than twice the mean deviation. American Meteorological Society defined drought as a period of abnormally dry weather, sufficiently prolonged for lack of water to cause a severe hydrological imbalance in the area affected.

Prolonged deficiency of soil moisture adversely affected crop growth indicating incidence of agriculture drought. It is the result of imbalance between soil moisture and evapotranspiration needs of an area over a fairly long period as to cause damage to standing crops and to reduce the yields.

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.

Low rainfall or failure of monsoon rains is a recurring feature in India. This has been responsible for drought and famines. The word drought, generally, denotes scarcity of water in a region. Though, aridity and drought are due to insufficient water, aridity is a permanent climatic feature and is the culmination of a number of long term process. However, drought is a temporary condition that occurs for a short period due to deficient precipitation for vegetation, river flow, water supply and human consumption. Drought is due to anomaly in atmospheric circulation.

Drought is a situation when the demand for water is much greater than the availability of water. Drought is a creeping phenomenon and it is experienced only after it has set in. The scarcity of water compared to demand will have greater impact on every activity of human life including failure of crops, food shortages, decline in ground water table, drying tanks, lakes or reservoirs, acute shortage of drinking water for humans and livestock shortage for cattle etc.

Drought will have very serious impact on economy of households as well as that of nation. There are five different types of droughts depending upon the nature of shortage of water

10.1 Meteorological Drought

Meteorological drought occurs when the water received through rainfall during a given period is much less than long period average rainfall of the area. The meteorological drought is associated with either failure of rain or due to long gap between the successive rainfall events. In India, meteorological drought occurs due to failure of south west monsoon or long breaks in south west monsoon rainfall. In Tamil Nadu the drought occurs due to failure of north east monsoon rainfall during months of October to December.

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.

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.

There are reports in financial newspapers that the ongoing (2010) drought affecting nearly 200 districts in the country may not have much effect on GDP, since the farmers in the drought-affected areas contribute hardly 3 per cent to GDP.  It is sad that such a measure of the impact of drought on the lives and livelihoods of millions of rural families is even considered. It is this mindset, typical of the growing insensitivity to human suffering in our country, that is responsible for India being the home for the largest number of undernourished and malnourished children, women and men in the world.  No wonder we are finding it difficult to achieve the first among the UN Millennium Development Goals, namely, reducing hunger and poverty by half by 2015.  Unless we realise that agriculture in India is not just a food- producing machine, but is the backbone of the livelihood of over 60 per cent of our population, rural deprivation and suffering will not only continue to persist, but will get worse, leading to severe social unrest.

Improving water use efficiency or enhancing agricultural water productivity is a critical response to growing water scarcity, including the need to leave enough water in rivers and lakes to sustain ecosystems and to meet the growing demands of cities and industries. Rainfall is the main source of water for the existence of life on the earth. Timely onset of rainfall and its distribution during the crop growing season determine the success of agriculture and food production. Unfortunately, the human life has hardly any control over nature and prevailance of delayed onset of monsoon and dryspells during different stages of crop growth are commonly observed in the dryland agriculture. Drought is a weather-related natural disaster which makes greater impact on food production and it reduces life expectancy and the economic performance of large regions or entire countries. Drought is a recurrent feature of the climate. It occurs in virtually all climatic zones, and its characteristics vary significantly among regions. Drought differs from aridity in that drought is temporary; aridity is permanent characteristic of regions with low rainfall. Drought is related to a deficiency of precipitation over an extended period of time, usually for a season or more. This deficiency results in a water shortage for some activity, group or environmental sector. Drought is also related to the timing of precipitation. Other climatic factors such as high temperature, high wind and low relative humidity are often associated with 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