eChapters

Abstract

A total of 30 groundwater samples were collected in four different seasons (Pre Monsoon, South West Monsoon, North East Monsoon and Post Monsoon) from the coastal aquifers of Kalpakkam region of Tamilnadu. The samples were collected covering the seasonal and lithological variations to infer the influence of natural geochemical processes and anthropogenic sources on the groundwater chemistry. The collected samples were analysed for the parameters like EC, pH and Major ions. The saturation index of silicates and carbonates shows that state of saturation to over saturation, but the sulphate minerals is dominantly under saturated. In the inverse modeling three models are obtained using PHREEQC and the error percentage is noted as 7.45%.

Abstract

The geochemical signature and vulnerability of groundwater of the East Coastal aquifers of  India from Pondicherry to Nagapattinam were determined. The coastal aquifers are fragile and this situation becomes more intense in aquifer systems like that of the Pondicherry to Nagapattinam region. A total of 136 water samples were collected during pre and post monsoon of 2008 and 2009 respectively. Out of which 45 samples for each pre and post monsoon from shallow groundwater and 23 samples for each pre and post monsoon from deeper groundwater.. The samples collected were analysed for major, minor cations and anions. Selected samples were also analysed for stable isotopes (d¹⁸O and dD). The analysed samples were studied for; their utility for different purpose, the nature of the geochemical classification, their variations in ion ratios, extent of sea water intrusion and the percentage of mixing, The study reveals that chief mechanism controlling shallow groundwater is the salts precipitated in the pore spaces during the Pre monsoon were leached and dissolved during the subsequent monsoon apart from sea water intrusion. Southern part of the study area  is more vulnerable than the Northern part of the study area.

Abstract

In semiarid climates, a significant component of recharge to basin aquifers occurs along the mountain front. In this scenario Mountain Front Recharge study has been carried along the foothills of Courtallam ,Tamil Nadu. A total of 53 groundwater samples were collected along the foothills and measured for major cations and anions using standard procedure. Saturation index (SI) of carbonate minerals like Aragonite,Magnesite, Calcite and Dolomite,LogpCO₂ and Ionic strength obtained from WATEQ4F output. pH plays a significant role in the saturation index of the minerals. Most of the Carbonate minerals shows undersaturation  with the pH range 7.5. Positive relationship between SI and HCO₃ is noticed. A sharp increase of pCO₂ values towards the foothills region suggests that the groundwater has been recharged by, acquiring longer flow path during its infiltration into deeper level near foot hill region. The SI of these carbonate minerals was spatially distributed to identify the areas of higher SI and also it is compared with the water level fluctuation to understand the recharge process along the foothill region as well as riparian zone.

Abstract

Quality of water is affected by natural and man induced contamination to groundwater system. Area chosen for study has gained its own importance due to the location of two lignite mines and a Thermal power plant in operation. Extensive large scale pumping of water is done for lignite mining. The mine drainage and drainage from thermal power plant along with agricultural return flow from lignite charged waters increases the severity of problem. In order to achieve a panacea for the above-mentioned situation, the study has incorporated and integrated in all related factors to get a meaningful interpretation for groundwater quality and quantity management in and around Neyveli area. The frequent failure of monsoon has added to the existing problem of over exploitation. To attain a panacea for water chemistry groundwater samples were collected for four different seasons. Higher EC and TDS values are observed in Southeast and Southwest part of the study area. In Southwest monsoon and Summer seasons HCO₃Cl dominates the anions, with few representations for SO₄. In Northeast monsoon and Post monsoon season Na + K – Ca + Mg is the dominant. Thermodynamic, studies reveal that groundwater of the region are stable with Kaolinite stability field in all the silicate systems. Bicarbonates derived from silicate mineral weathering are noted in the NW, Northern and in the mining region. These regions are located in the NW and NE part of the study area. Comparison of water quality to standards shows that the water can be used for drinking and for irrigation purposes except in few locations.

Abstract

Radon being the radioactive daughter product of Uranium; the interrelationship between U and Rn has been established in the present study. It is found that Radon coexist with Uranium in the region. A total of 61 samples were collected spatially from hand pumps and bore wells of the study area. Major ions such as Ca²⁺, Mg²⁺, Na⁺, K⁺, F^-, Cl^-, HCO^3-, NO^3-, H₄SiO₄,PO₄- and SO₄^2- and U, Rn were analysed. The lithological influence of U and Radon occurrence is also highlighted. Hard rocks especially Granites are the source for both U and Rn in the study area whereas the lack of correlation exist between U and Rn in sedimentary terrain can be attributed to difference in flow conditions and chemical properties of these elements. 

Key words: Radon, Uranium, Granite, Ground water, Source.
 

11.1 Introduction

The laws governing the flow of water in wells are referred to as the hydraulics of wells. Just like surface water flows from a higher elevation to a lower elevation by gravity, groundwater also flows from a region of higher water table to a region of lower water table. This difference of water table measured by any two piezometers divided by the longitudinal distance between them is called as hydraulic gradient. Hydraulic gradient plays a dominant role in deciding the flow of groundwater. This hydraulic gradient together with the hydraulic conductivity of the aquifer material forms the main law of well hydraulics called as Darcy’s law. An understanding of Darcy’s law together with some other laws as discussed subsequently in this chapter is essential in order to know the discharge of a well in a particular formation. Darcy’s law is valid for studying groundwater flow in alluvial formations. However, it is not valid for aquifers having hard rock areas.

10.1 Introduction

During rain or heavy irrigation, a part of the rainfall or irrigated water moves below the effective root zone of the crop which moves further below and adds to the water table lying above the impermeable bed or hard rock which is called as  ground  water  reservoir. At  times  the  accumulated  surface  water  is  also recharged to the soil reservoir both naturally as well as artificially that add to the underlying ground water reservoir. This groundwater is an important source of water for irrigation as well as domestic uses. It is the most abundant fresh water resource of the earth. Underground water reservoirs contain large stock of fresh water resources. Total quantity of groundwater within 800 m distance below  the  ground  surface  is  more than  30  times  the  total  water  in  all fresh water lakes, more than 60 times the total water in soil and other unsaturated rock materials, more than 300 times the water vapour in the atmosphere and 3000 times the average volume of all rivers and rivulets in the world (Lenka, 2001). But the distribution of groundwater is not uniform.

Bhuva is a small village in north-west Gujarat – India.  My mother was born there. The loving people of Bhuva called me ‘Bhano’ (Sister’s Son / Nephew) and it was my favourite place to go as a child. I have my fondest memories of Bhuva, but could not visit for several decades, until when I was once at the Junagadh Campus of Gujarat Agricultural University, to inaugurate the International Conference on New Developments in Agriculture. Bhuva was not too far and I decided to go there. Soon as I reached, a familiar face, now aged with time, recognized me from a distance and with tears rolling from his old eyes (and mine) he hugged me, calling out “MaroBhano, MaroBhano” (My sister’s son, my sister’s son)! Now in his eighties, it was overwhelming to meet Nanji Ata, who I always remembered being wise, educated and cheerful. He was a relatively progressive farmer with about 6 to 7 acres of land, a few cows and a buffalo. Though water was scarce and saline, he managed to make a good living and was considered a well to do man.

It is well recognized that sustainable management and sustainable livelihoods are inseparable. If neglected and if the present trends are not corrected in time, everyone’s future is threated. On the other hand, there is increasing recognition of living examples and demonstrated evidences of how the eco agricultural practices can help provide a solution to some of the major problems of today and tomorrow. Also, the main stream international agencies are emphasizing that agro-ecological approaches are the way forward. What the policy makers, farmers and people would like to know is How !it has been our experience that in most countries of the developing world the answer to ‘How’ of eco-agricultural is being demanded!

Our Soils – Our Waters & COP22

In the last several decades many international forums and institutions have discussed and agreed that food and water security are the most important issues for the future. The damage to the ecology directly affects the food, land, water, health and the livelihood. Agricultural progress serves as the best way to fight poverty, hunger and livelihood problems.

Though in the last few decades, billions of pages about hunger, food and water security have been written, thousands of conferences have been organized, the urgency of action plans and creating holistic models is the most important need. For this, we must require bold reforms and action oriented programs which can reach the smallest farmers and give an optimistic signal rather than a despondent picture. Developmental models that are holistic and close to nature, sustainable and based on inclusiveness considering ‘unto the last’ women and man are the need of the day.

In contrast to the traditional universities, agricultural universities have been entrusted with the Herculean task of technology dissemination at the grass root level such that the package of practices evolved by the agricultural scientists should reach out the end-users, viz. farmers , for adopting in the field, with consequent increment in the farm productivity and farmer’s income.

This unique mandate has been assigned to agricultural universities on the pattern of land grant colleges of the United States. Such vision and trust, envisaged by Pandit Jawaharlal Nehru and his devout lieutenants, herald creation of state agricultural universities (SAUs) in the early 1960s. The key role played by SAUs in the first green revolution and agricultural human resources development have been regarded as the milestones in the history of India post-independence, that made the country self-sufficient in food production and, in turn, to self reliance in milk, vegetables, fruits and inland fish production.

"Where is your Dhoti, Dr. Mehta ?” Dr. Varghese Kurien surprised me as I entered his office at IRMA (Institute of Rural Management Anand). That was April 2000, soon after I had taken over as the Vice Chancellor of the erstwhile Gujarat Agricultural University (GAU) and had decided to call on him during my visit to the Anand Campus. (At that time GAU was the largest University in the Asia with four main campuses – Dantiwada, Anand, Junagadh and Navsari and about 65 experimental farms / stations spreaded all over).

The Late Dr. APJ Abdul Kalam is described as a great patriot, visionary leader and the 11th President of India ( 2002 – 2007 ). The country would have celebrated his 84th birth day on 15th October 2015. To many like me, he was the most ideal role model that the youth of India needed, in recent time. He emerged as a complete human-being who touched the lives of people.

My first meeting with him was when he visited IPCL in eighties - as the DRDO Chief to discuss about Carbon Fiber and Composites. I was heading GSFC’s R&D Centre and other facilities like engineering plastic Nylon – 6 and their Composites and hence was invited to join the discussions. That interaction left a strong impression in my mind. Later when I became Vice Chancellor of Gujarat Agricultural University, I had many more opportunities to meet him and was often surprised at his deep rooted interest and knowledge in every sphere of Science & Technology. Subsequently, to my delight, I received an invitation from his office on the eve of 26th January evening - at home with the President and later was given more time for a one-to-one meeting the next day. Walking across the corridors of the Rashtrapathi Bhavan, the atmosphere looked rather formal and uneasy for me, but, as I was ushered into his room, I saw Dr. Kalam wearing his favourite blue shirt and smiling. He moved forward and greeted me with the same friendliness and warmth. As we started talking about Agriculture scenario, the work I was planning and the future prospects, I marveled at his understanding and insight and left the room truly inspired. 

Rivers are the most important system for water, for irrigation and human settlement. Historically, civilizations always nucleated near rivers, and latter also had social and religious significance. Rivers in India are considered holy and play the most important part in the lives of people, fauna & flora and the future environmental system.

The Ganga Basin is the largest river basin in India which includes the Ganga, the Yamuna, the Ghagra, the Gandak, the Kaveri basin etc. Compared to these, the Vishwamitri River, situated between Mahi River in North and Narmada River in South in Central Gujarat is a small seasonal river but it is very important for the city of Vadodara and Central Gujarat region. This seasonal river originates from Pavagadh hills and flows east to west. It is a typical small river with the kind of problems in most rivers in India and other countries – liquid and solid wastes, enouncements, blocking of water ways, floods in monsoon months and dry dumping basin during most other months etc.

All agriculture universities have three main Directorates – Education, Research and Extension. Of the three, I have often observed that Extension Department comes in for maximum criticism. ‘Loose links’and ‘need to do much more in transfer of knowledge and technology’ are frequently emphasized at various levels – especially in meetings with farmers groups.

This is understandable – as it is said that less than 10% - often less than 6%, of lab scale knowledge and development reach the farmers fields in developing countries and even in many ‘developed’ counties. The situation is much more challenging when we consider a large population of small and marginal farmers – who as we saw can play extremely important role in eco-agriculture. A large percent of such farmers – women and men are practicing eco friendlyagriculture without realizing it. Their ‘ignorance’ can be converted in to advantage and new opportunity. The age old extension practice of reaching farmers through meetings, visit , seminars, camps, demonstrations all have limitations and need to be ‘scaled up’. New developments in information and communication Technology offer a great opportunity for a big jump in reaching the unreached. Again to alarge population of ‘Green Revolution’ – there is a new hope and opportunity.

Saline Water Agriculture has been drawing interest as one of the solutions for limitation of world fresh water supply, farmland availability, salinity ingression and the pressing future need of food supply. The cultivation of salt-tolerant crops on saline soil and with saline waters has significant social and economic potential.

It is often argued that fresh water agriculture near rivers and ponds was invented because of the need to sustain people and communities. Saline water agriculture is going to be needed for sustaining our future generations and civilization.

Bioshields offer barriers of vegetation, shrubs, small and big trees and if integrated as a well designed system they can greatly help our coastal as well as inland areas. Though primarily looked at for coastal regions, under a broader definition Bioshields can play important role in semi-desert areas, hills, etc. also.

Why Bioshield?

Bioshields or Biobarriers can make a major contribution in minimizing the effects of storms, cyclones and Tsunamis and at the same time offer short and long term ecological and livelihood benefits.

The recent earthquake in Nepal brings back memories of 26th January 2001. While the nation was busy in celebrating Republic Day, an earthquake shattered Gujarat especially Kutch and Saurashtra regions. A large number of buildings and houses collapsed within moments. Thousands were injured and many lost their lives and many more became homeless.

Kutch received quick responses from all over the world and a large number of individuals, institutions, government and semi-government bodies, professional experts, religious and social organizations etc. sprang into action to bring back some normalcy in the lives. However, long-term rehabilitation program based on scientific planning is most vital after such disasters.

It is estimated that the country needs about 245mt of food grains, 30mt of sugar and jaggery, 7 lakh of tea, 1.7 lakh t of coffee, 10mt of vegetable oil and 17m bales of cotton. For realizing this, irrigated agriculture has to play an important role. To achieve this water use efficiency (WUE) in the irrigation sector has to be improved considerably as bulk of the available water is used in agriculture. But, with the ever-increasing population and industrialization problems, the demand for water by these sectors is bound to increase manyfolds in future. The requirement of water by different sectors during 2025 is estimated to be 105 m ham, which is 30 m ha m more than the present one. The share of water utilization for agriculture is expected to get reduced from the present percentage of 8~ to a value of 73 by 2025. Further, the demand for water for agricultural purposes is estimated to increase from 470 krrr’ to 740 krrr’ in a period of four decades (Table 1). During the same period there will be four­fold increase in the water demand for non-agriculture purposes.

Since many decades environmentalists have warned of perils of chemicalised sports grounds, golf courses and cricket fields. They warn that our health is inextricably linked to the widespread use of toxic chemicals and also complain about the non-availability of safe alternatives.
Eco-sustainable sports fields must use the methods : 
    ·    That do not pollute
    ·    That are environment-friendly and effective
    ·    That economize on the use of water and energy