eChapters

Abstract

Aquifers are usually composed of permeable layers that can ways a considerable amount of groundwater. Usually, aquifer units are correlated through the concept of lithostratigraphy. For low-permeable aquifers, it is difficult to define the spatial distribution of hydrogeological units, and this study attempts to use geochemical methods to identify the groundwater flow paths in an area of Southeast coast of Tamil Nadu, India. Multiple geochemical analyses, including groundwater chemistry; stable isotopic compositions of d¹⁸O and 8D contents were performed.  Spatial distribution of d¹⁸O, dD, Cl-/HCO-₃ show that northeastern part of the study area seriously affected by seawater intrusion. The highly permeable aquifers at the east coastal region are characterized by high hydraulic conductivity as compared with other regions of the study area. Hydrogeochemical characteristics based on bivariate diagrams of major and minor ions show that changes in the chemical composition of groundwater are mainly controlled by the salinization process followed by cation-exchange reactions.

Real time weather data at different time intervals is very important for the crop weather studies, but through the agro-meteorological observatories such real time weather data are generally not collected. The acquisition of agro-meteorological data through conventional observatories requires services of trained personnel to collect, compile and creation of weather data base. With the advances in technology, weather observations are automatically recorded, stored and can be transmitted to the remote place with the help of Automatic Weather Station (AWS).

The agro-meteorological data after the quality control is used to establish a relationship between the crop and weather or to understand their interactions. In agrometeorological data analysis, statistical tools are used. The frequent use of statistics terms and their computational formulas are given below for ready reference:

Abstract

Dissolved Organic Carbon (DOC) consisting of water soluble organic molecules and by products of organic decomposition and chemical degradation processes, constitutes a critical link in carbon and nutrient cycles. The quality, or chemical and physical character, of DOC affects the degree to which it is transformed by biological and chemical processes. The significance of DOC was studied in layered coastal aquifers of the Pondicherry region during four different seasons. Pondicherry region has varied geological set up ranging from Cretaceous to Recent formations. A total of 52 groundwater samples were collected from various aquifers like Alluvium, Tertiary(Upper Cuddalore, Lower Cuddalore) and Cretaceous for two different seasons of pre- monsoon(PRM), and post-monsoon (POM). The samples were analyzed for major ions and DOC. The range of DOC in the study area is 0-14 mg/l. Very high DOC concentrations were measured during PRM in the samples from Alluvium and Lower Cuddalore Formation. The samples of these formations were compared with pH, Ionic strength, log pCO₂ and carbonate minerals concentration. The alluvial aquifer shows that pH governed dissolution along the coastal tracts and in Upper Cuddalore formation it’s based on interaction between aquifer matrix and groundwater.

Abstract

Groundwater is most favored as a source of drinking water in all over world. It is often thought to be cleaner and easier to treat when compared with surface water and as a result, many wells have been sunk. Uranium and other radionuclides in water can lead to health problems if present in higher concentrations. In order to study the behavior and to understand the influence of lithology in groundwater of Madurai district, a study was conducted by collecting a total of 216 samples of different seasons (Premonsoon, South west monsoon, Northeast monsoon and Post monsoon) with respect to lithology and the number of samples was depending upon their spatial coverage in the study area. The groundwater samples were analysed for U, Ca²⁺, Mg²⁺, Na⁺, K⁺, HCO₃^-, Cl^-, SO₄^2-, PO₄^3-, NO₃^-, F^-, H₄SiO₄, pH, EC, TDS. It was identified that the higher concentration of Uranium (156 ppb) were noted in the northern part of the study area. They are chiefly restricted to the Granitic terrain and nearby Charnockitic regions. The weathering process induces the release of higher U ions from the granitic terrain and the evaporated recharge water from the tank /reservoir  also induces the release of U ions from the rock matrix, it may also be due to fertilizer enriched agricultural return flows. The key source for all these processes and hydrogeochemical processes is identified to be lithology which inturn controls all the other processes in the study area.

Abstract

Amongst all types of major land-use change, extending irrigated agriculture using a surface-water source has the greatest influence on groundwater – both significantly increasing recharge and changing water quality as excess irrigation water infiltrates into shallow aquifers. Hence, in order to understand the impact of the landuse on the groundwater system the study has been aimed to understand the process by adopting geophysical, geochemical and microbial analysis of groundwater samples. The study has been conducted in Chidambaram taluk, with a total area of 92.51Sq.km. A total of 39 groundwater samples were collected for the analysis of major cation and anion along with the microbial analysis, like Total Coliform, Total Viable Counts, Fecal coliforms, Vibrio cholera and Total Streptococci. The geochemical studies reveal that there is no correlation between these parameters and the microbial population. The migration of the water from the elevated regions (urban region) is witnessed and the concentration of the microbial population is higher in these regions except in the southern region which has impermeable clay and this arrest the movement of water.

Heat units also called growing degree-days (GDD), effective heat units, or growing degree units, are a heuristic tool in phenology. GDD is a simple means of relating plant growth, development and maturity to air temperature. The concept is widely accepted as a basis for building phenology and population dynamic models. Degree day units are often used in Agrometeorology, Agronomy, Entomology and Pathology essentially to estimate or predict the lengths of the different phases of development in crop plants, insects, pathogens etc.

7.1 Introduction

The current atmospheric CO₂ concentration is the highest during last 650,000 to 800,000 years (Luthi et al., 2008), and also probably in the last 20 million years (Pearson and Palmer, 2000). Since last two decades, it is increasing at a rate of about 2 ppm/yr with the current concentration of 389 ppm in 2010 (WMO, 2011). The current trend of energy use based on fossil fuel consumption may raise it to 900 - 1100 ppmby the end of 21^st century (Kiehl, 2011).

Global warming is the most prominent environmental issue across the world. It is caused by the increased concentration of greenhouse gases (GHGs) in the atmosphere and leads to a phenomenon widely known as ‘greenhouse effect’. Amongst various sources of greenhouse effect, agriculture is considered a major contributor primarily through the emission of greenhouse gases such as methane, nitrous oxide and carbon dioxide.

Abstract

Geochemical processes occurring within the groundwater and reactions with aquifer minerals have a profound effect on water quality. Hydrogeochemical composition of groundwater can also be indicative of its origin and history of passage through underground materials which water has been in contact. Assessing groundwater quality and developing strategies to protect aquifers from contamination are necessary aspects for proper planning and designing water resources. Anthropogenic activities like explosion of population, industrial growth, inputs of fertilizer, pesticides, and irrigation has been a crucial factor for determining the quality of groundwater. In this scenario, 43 groundwater samples were collected from the Dindigul district of Tamilnadu, a Hard rock terrain. The samples wereanalyzed for major cations and anions along with heavy metals to derive the different quality parameters and to obtain the pollution indices of different samples. This study focuses to find out the spatial relationship between the analyzed fluoride concentration in groundwater and pollution indices derived from the heavy metal concentration in the groundwater of the study area and their variation with respect to season.

In his classic book ‘The Ascent of Man’, Bronowski has written, “When I was a young man, we all thought that mastery came from man’s domination of his physical environment. Now we have learned that real mastery comes from understanding and moulding the living environment.” Our Biosphere, the living environment that supports us all, has problems and we humans are mainly responsible. We do not live ‘gently’ on the earth. The seven billion of us require air, water, food, energy, housing and amenities and we have developed the earth to provide them and have also created problems. That the problems exist are serious is the bad news. That we are recognizing them and that man has shown ability to organize and grow in ascending order from time to time is the good news.

It has been repeatedly proving that Science& Technology that is close and in harmony with nature is proving winner in the long run. If the past 60 years led to the Green Revolution in agriculture which often became Greed Revolution, the next 60 year should be the emergence of love for nature, diversity and Sustainable Green Revolution. The two goals – Sustainability and Productivity are inter-related.

It is also said that the main difference between the past and today is that our problems are truly global. We are also aware that globally and nationally the rich-poor divide is growing and though world produces enough food, nearly 800 million people remain food insecure. Among 8 millennium goals, eradication of poverty and hunger and environmental sustainability are perhaps the most prominent and complimentary.

The words “Economy” and “Ecology” have the same root. Both these words are derived from Greek ‘Oikos’ means house or house holds and both imply thrifty economical way of dealing with valuable resources. However, for some reason we seem to find these two words coming opposite each-other in many situations.

The destruction and degradation of the environment has become the greatest problem of our century. Our survival will depend on how well we are able to redefine our technologies and our relationship with nature. We therefore need a new sustainable eco-agri revolution and a country like India is in an ideal situation to give a model for that. In the new economy, good ecology will be fundamental to good business.

African agriculture is in crisis, and Africa’s farmland is losing its fertility at an alarming rate. Farmers grow the same crops in the same fields year. They don’t fertilize, and they don’t terrace their fields. When the soil wears out, the clear a new piece of land (wwww.npr.org). N. Kozana Diamini Luma, the Chairperson of the African Union Commission has emphasized that ‘the year 2014 – the year of Agriculture in Africa’ will be used as an opportunity to accelerate the drive for food security. The major thrust for that has to be on ensuring that the farmers make their profession on economic activity that generate wellbeing for all in a sustainable manner (1, 2).

Any living organism in its natural habitat is called a wildlife. It may be plant animal or a microbe. The significance of wild life lies in setting up the balance of population in nature by maintaining food chains and food webs. It acts as the gene banks in relation to breeding of plants and animals for introduction of desirable characters such as high yield of economic product and resistance to diseases. The scientists are performing studies to screen and select useful genes in economically important organisms.

Air is one of the most important constituents of man’s environment. It is calculated that a roan breathes about 22,000 times a day inhaling about 16 kg of air by weight. Air is present everywhere and its entrance from one place to another cannot be checked. Clean and pure air is very essential for the health and survival of man.

El Nino is the name given to the occasional development of warm ocean surface waters along the coast of Ecuador and Peru. When this warming occurs the usual upwelling of cold, nutrient rich deep ocean water is significantly reduced. El Nino normally occurs around Christmas and lasts usually for a few weeks to a few months. Sometimes an extremely warm event can develop that lasts for much longer time periods. In the 1990s, strong El Ninos developed in 1991 and lasted until 1995, and from fall 1997 to spring 1998.

Higher Farm Production with Lower Input Cost

There is a great need to reduce the input costs and at the same time improve the farm productivity in a sustainable manner. A model has been worked out based on a number of field demonstration studies in different parts of India, Africa and Far Eastern countries. A model in which input cost can be reduced by nearly 20 percent and at the same time the crop production can be enhanced upto 20 percent is possible and can be a boon to farmers in most parts of the world. This is the model, which can be easily adopted in an evolutionary way. As suggested by Jonathan Foley (BOX – 1), use of high-tech, precision farming systems, as well as approaches borrows from organic farming, we can boost farm productivity substantially.

At an Agri Summit, I had a very difficult task to chair a session on “Sustainable Future”, with two well-known but extremely opposite personalities. On my left was a globally well-known environment activist talking about all the evils of chemical fertilizers and chemical pesticides. On my right was the President of Pesticide Association with equally strong views about how the chemical pesticides have greatly helped in feeding the hungry world. My task was further made difficult by a large lobby of green activists in the audience and also a number of seasoned industrialists with opposite views. Such a scenario is becoming increasingly common.

Composting is organic matter that has been decomposed and recycled as fertilizer and soil conditioner. It is a natural process of decomposition and recycling of organic material into humus rich soil amendment.

At the simplest level, the process of composting requires making a heap of organic material sprinkled with water which break down to humus after a period of weeks or months. However, modern bio composting is a multi-step, closely monitored process with measured inputs of water, air and carbon and nitrogen rich (in proper C:N ratio) materials.