eChapters

“Hydrology is the science that treats the waters of the earth, their occurrence, circulation and distribution, their chemical and physical properties, and their reaction with their environment, including their relation with living things. The domain of hydrology embraces the full life history of water on the earth.” (Federal Council for Science and Technology, “Scientific Hydrology”, Washington, 1962)

This definition puts in a nutshell what is most often inadequately done before undertaking exploitation of water resources. In short, it is the scientific inputs that are likely to be missed while planning water resources management projects. It is the “full life history of water” part of the above definition that is of specific relevance to the theme of this book, Isotope Hydrology.

Conventional hydrology is strong on measurement and quantification of different parts of the hydrological cycle (Fig.1.1), be it precipitation, run-off, evaporation, transpiration, infiltration, groundwater dynamics etc. Through chemistry and isotopes, we try to understand the processes themselves in order to delineate the history of that part of the hydrological cycle that is being studied. For example, if we are measuring river flow, we would like to know the contribution of different components; base flow, rainfall run-off and snow melt, if any.

Let’s see what we know and what do not know in the conventional hydrological practice. We know surface waters evaporate, form into clouds and precipitation occurs under favourable weather conditions. What we often do not know is the source of moisture, oceanic or inland.

1.1 Water and its Importance

Water has played a crucial role in sustainace of lives of all living beings including animals, plants and human beings in this earth since time immemorial. It is there since the creation of the nature and will probably remain till the destruction of the nature. It is used in multifarious uses including domestic, industrial, agricultural, recreational and many other uses. It occurs in the nature in practically three forms i.e. solid, liquid and gaseous forms. All the three forms are important to living beings; but the liquid form of water is more beneficial. The weight of the water helps in running hydroelectric turbines, the density of water helps in floating the ships, the steam energy produced by heating the water helps to run the locomotives and thus is beneficial in many ways. It is considered as the most important resource of the society. It has become part and partial in our life so that we cannot live without water. That is why water is called as life.

The entire world is now facing a crisis situation. The problems encountered to address the crisis are interactive with each other and there is no easy way to find solution. The world’s population is expected to increase by 70 per cent by the end of year 2050 and there is need to step up agricultural production for a hunger free world. Nearly 70 per cent of the fresh water is used in agriculture sector. The demand for water in agriculture sector can be judged by the fact that several thousands of litres of water is required to produce one kilogram of food grains. Whatever maybe the source from which water is drawn for agriculture, all the sources depend upon the precipitation for replenishment on continuous basis. The precipitation patterns are not consistent and are known for greater variability from season to season, year to year and from region to region. These inconsistencies are further increasing due to recent threat of climate change triggered by the atmospheric pollution. The atmospheric pollution due to increase of greenhouse gases in the atmosphere is responsible for rise in temperatures. The rise in temperature induced changes in global pressure and wind systems. The consequence effect of it is changes in rainfall patterns, frequent occurrence of extreme weather events like floods, droughts, heat waves, intensified cyclonic activity. Rise in temperatures is increasing evaporation of water and water requirement of crops as well. There is considerable increase of the chemicals in the agriculture sector in the form of fertilizers, pesticides, fungicides and weedicides how to increase crop production and protection of crops from biotic and abiotic stresses. Consequently, there is increased pollution of water resources which may adversely affect the availability of fresh water, which is essential and critical input in agriculture for increasing agricultural production. It calls for efficient utilization of water resources in agriculture. More concerted efforts are required immediately to:
• Improve water use efficiency in agriculture
• Reduce pollution of water resources
• Conservation of fresh water resources
• Reduce emissions in agriculture sector and
• Prevent dwindling of fresh water resources

1. GEOLOGY

Geology : Earth Science

 Geo = Earth + Logos = Science

 Def : The science which investigates the history of the earth is known as geology.

 Following are the important branches of geology.

1.Coal Geology : it is related with natural gas, coal deposits and their formation.

2.Crystallography : includes the crystal and atomic structure of the mineral. 3. Drilling Technology : it is related with the cores, core logging and coorelation of the lithology.

4.Engineering Geology and Surveying : it is related with engineering aspects of the earth.

1.0 Overview

Natural resources sustain life and are critical for economic development of nations. In developing countries like India where more than half the population is rural, economic development is inextricably linked with agricultural development. In these countries, the food and livelihoods security of the poor are critically associated with access to the services provided by the natural resources - land, soil, water, biodiversity and climate resources. The natural resources are finite, and with increasing population, economic growth, urbanization, and demands for food and other agricultural commodities, these are being increasingly strained. As a result, the productive capacity of the natural resource base is shrinking and deteriorating. Sustaining the productive capacity of natural resources for future generations, while meeting the food and other demands of the growing populations, is the major development challenge of the twenty first century.

In India, during the last forty years the net sown area under agriculture has remained nearly constant at 141 million ha. In the same period, the population has more than doubled (from 541 million in 1970 to 1186 million in 2010) and per capita income grew by more than 3.5 times (from Rs 14824 in 1970 to Rs 53331 in 2010). As available land resources for agriculture are finite, increases in agricultural production to meet the growing demands of the population have to come from intensification of agriculture on the same lands. As a result, the quality of soils on these lands is gradually deteriorating both at the farm and ecosystem levels. The major threats to soil quality come from loss of organic carbon, erosion, nutrient imbalance, compaction, salinization, water-logging, decline in soil bio-diversity, urbanization, and contamination with heavy metals. More than 100 million ha of the total cultivated land of 141 million ha is stated to be under some form of soil degradation.

Similarly, utilizable fresh water resources of India are finite at about 1123 billion cubic meters (BSM), of which about 690 BCM are from surface water resources and 433 BCM are from groundwater. This supply is shared among multiple uses: human and animal consumption, agriculture, urban uses, industry and for provision of environmental services. The total water demand in 2010 is estimated at 710 BCM and is projected to increase to 1180 BCM by 2050. Several parts of India are already facing severe water shortages as a result of the growing demand for water. The quality of water resources is also impacted by agricultural intensification and development, and is increasingly a matter of concern. By the year 2050, when population is expected to stabilize, the shortages will only intensify. The country as whole can be on the verge of becoming a water scarce country, with nearly all the presently estimated utilizable water resources being put to use.

Biodiversity natural resources refer to the abundance of different species and ecosystems in nature. These resources are the primary sources of present and future productive agriculture and human well being, as they provide the basic resources for use in breeding crops and livestock, soil formation and structure, soil fertility, nutrient cycling and the provision of water services. India is among the 12 mega diversity regions of the world. It is known to have more than 18,000 species of higher plants including, 160 major and minor crop species and 325 of their wild relatives. Increasing pressure from human population growth, agricultural intensification, urbanization, pollution and degradation of land, soil and water resources are having a negative impact on the plant, animal and microbial biodiversity resources of the country and their productivity.

ABSTRACT

Due to complex hydrogeological conditions it becomes very difficult to prospect the ground water resources especially in drought prone areas where the water table is very deep. The interpretation of geoelectrical sounding curves also becomes ambiguous. A semi empirical method namely theinverse slope method [Shankar Narayan and Ramanujachari, NGRI] is widely used since it is simple to operate without standard curves etc and it gives fairly good results. In some Government organizations like PWD [Ground Water Department] and TWAD Board of Tamilnadu, this inverse slope method is widely used for ground water exploration. Based on this methodology, ample of bore well points have been recommended in complicated hard rock terrains and the success rate is found to be encouraging. The study area, Kavalpatti, of Palani taluk in Dindigul district is a crystalline rock terrain, where geological, hydrogeological and geoelectrical investigations have been carried out to explore the ground water potential zone for agricultural purpose. The bore well drilled to a depth of 32 m has yielded 370 lpm. The interpreted geoelectrical section has been correlated with the litholog of bore well. Some bore well statistics [bore well points recommended based on this method] has been furnished, which reveals that this methodology is encouraging.

The purpose of irrigation scheduling is to decide upon the amount of water to be applied for irrigation and timing of irrigation in order to avoid wastage of precious water. The irrigation scheduling is also used to determine the number of irrigations required for a crop during its growth cycle and judicious use of water depending upon the weather forecasts issued from time to time. The irrigation scheduling has to be planned for either full irrigation or supplementary irrigation depending upon the availability of water resources and the season during which crops are grown. Crops grown during the dry season requires full irrigation and crops grown during the rainy season require supplementary irrigation. The third category of irrigation is protective irrigation which is practiced in dryland areas. The protective irrigation is given when the crops are experiencing severe moisture stress due to prolonged dry spells wherever the farmers has access to small ponds and tanks developed within his own field as water harvesting structures.
10.1. Full Irrigation
Under full irrigation, the crops are provided with irrigation right from land preparation till the crop is getting ready for harvest maturity. The full irrigation will be usually planned for maximum yields of the crop (Fig.10.1).

OBSERVATION

The examination of the IRS - 1A imagery under raw and the digitally enhanced modes vividly display heavy concentration of suspended sediments in certain sectors along the east coast of Tamil Nadu. Such pockets of suspended sediments are seen as long and linear bodies trending parallel to the coast to the strike length of 20 - 30 km and width of 5 - 10 km. Such Phenomenon of suspended sediments concentration are strikingly observed in two sectors. One in between Tuticorin harbour and Vaippar river mouth and the other just at the mouth of Ponnaiyar river along Cuddalore-Pondicherry coast. Both of them are observed along conspicuous (Fig.1& 2) concave coasts.

After precipitation, run-off and surface water storage in lakes and man-made reservoirs, the next steps in the hydrological cycle are infiltration through the unsaturated zone and groundwater dynamics in the saturated zone. Well-established applications of isotopes in groundwater hydrology are

The range of isotope applications in surface water hydrology is not as wide as in groundwater hydrology as the surface waters are more easily amenable to conventional hydrological methods. Following are the areas in which isotopes have a significant role in either improving the accuracy of measurements or in providing additional information, which is otherwise not easily available.

Abstract

Kaliasaur landslide located 18km from Srinagar on the NH-58 in Uttrakhand Himalayas has been repeatedly sliding for the last over 5 – 6 decades totally paralyzing the transport operations in the region and causing beeline of issues not only for the people living in the hilly state but also the tourists and the pilgrims. The study of Geosystems & geodynamics, large scale micro zonation and geotechnical studies using RMR and SMR techniques show that the slide is located in high hazard zone and follow the pattern of wedge and planar failures with vulnerable zone of factor of safety. The toe erosion by the acutely turning Alaknanda river and the mitigation measures in the form of slope disturbance in the upslope part rather protecting slide, has been responsible for the recurring slides. The study further revealed that excessive rainfall is also a triggering parameter and the crown part is widening. On the basis of the studies, mitigation measures have also been brought out.

Keywords: Kaliasaur landslides, Micro LSV zonation, Factors of landslides, Mitigation.

Abstract

Historically, the tiny island katchatheevu located in between Rameshwaram and Srilanka belongs to Ramnad Kingdom and it was handed over to Britishers and during the British’s rule. During that time both Indian and Srilankan fishermen communities were using this for their fishing related activities. On a goodwill, in 1994, the Government of India donated this island to Srilanka. Since then it has become a major issue and a perpetual problem to Indian fishermen that they could neither do fishing around nor berth their boats for drying their fishing nets. Under this scenario, an attempt was made to evaluate the geological setting of Katchatheevu island using E-Topo data which provides the sea bottom topography/morphology. The study revealed that the Katchatheevu island is the north eastern extension of the Pisasumunai of the Rameshwaram island and such arcuate nature of the land between the Pisasumunai and Katchatheevu is attributed to anticlockwisly spiralling littoral currents which would have dumped the sands and developed the island. Thus the study brings some newer information that the Katchatheevu is geologically a part of Indian land mass.

Studies and Findings

The boundary problems within the nations and amongst the nations, especially amongst the territorial nations, have started emerging as major issues of global concern. Katchatheevu Theevu located between India and Sri Lanka is one such a major issue, as the said island which originally belonged to Ramnad kingdom was handed over to Sri Lanka by India in 1974 and since then, the Indian fishermen community is facing untold miseries in the hands of Sri Lankans and hence it warrents immediate attention.

2.1 Beakers

Beakers are the one of most important vessels used in laboratory which is made up of heat resistant glass.

They are available in various capacities ranging from 10 to 3000 mL.

For convenience of pouring solution, spout is provided in the beaker.

They are used to perform titrations & for boiling solutions, etc.,

Beakers are constructed in tall and low forms.

The Resource of Land
One limited natural resource is land. The resource-generating regions found in terrain forms such as hills, valleys, plains, river basins, and wetlands are essential to the livelihood of the inhabitants. An ordered combination of minerals, organic matter, living things, air, and water is called soil. The soil is bound together by grass and tree roots. Land becomes unproductive and turns into wasteland when trees are reduced in size or grasslands are overgrazed.
Land is a valuable resource because it supplies the necessary substrate for the growth of vegetation, forestry, agriculture, and other industries. Approximately 54% of India’s land is used for agriculture. Land is necessary for man to construct dwellings, cultivate food, maintain pastures for domesticated animals, create towns and cities to support industries, and develop industries to produce things.
Degradation of Land
It can be characterized as any alteration to the land that lowers its quality or condition and, consequently, its capacity for yield. It happens anytime human activity alters the natural equilibrium of the environment through abuse or overuse. The main issues with land degradation are:
• Erosion by wind
• Water erosion including large-scale hillside movement
• Salinity of dry terrain
• The salinity caused by irrigation
• Surface scorching of soil
• Logging using water

Abstract

The softer rock types belonging to Tertiary period, intense deformation and the related more frequent tectonic weak planes, high degree of weathering and extensive road cutting are the inherent systems in provoking Landslides in Noney-Nungba segment of NH-53 in the state of Manipur. So Landslide Hazard Zonation mapping was carried out in this segment using BIS method and also geotechnical investigations were carried out in Awang Khull part-II slide and Raungdai slide and on the basis of type of failure and the morphotectonic conditions mitigation strategies were suggested.

Abstract

Landslides are the most common hazards in hilly regions. Rapid development and the resultant uncontrolled interactions with ecosystems are the major reasons for the landslides, besides the rainfall. So, the assessment of landslides hazard vulnerability is a prerequisite before making any developments related to settlements, hill resorts, hydropower projects and the related network of Ghat roads. The present study deals with the assessment of landslides in two different sites; Site-1 located in the Ghat section of Yercaud hills between 10/4 and 29/6 km stones in the southwestern slopes of Shevroy hills, Salem, and the Site-2 located in the Ghat road between Lower camp and Kumuli in Theni districts, Tamil Nadu. The Theni ghat road in the National Highway-220 is connecting Tamil Nadu with Kerala and is the lifeline for Sabarimala, Tekkadi and Munnar. Besides, a series of pan stacks conveying water from Periyar reservoir in Kerala to the power house located at Lower camp in Tamil Nadu also lie in this stretch of hills. Landslide vulnerability mapping was carried out in an area of 130sq.km in Site-1 and 6.7 sq.km in Site-2 by assigning numerical values to the causative factors of slope instability such as lithology, structure, slope morphometery, relative relief, land use and land cover, and ground water conditions following the BIS code No. 14496 (1998) for preparing landslide hazard zonation maps. The study in Yercaud hills revealed that out of 12 slope facets, facet 1 to 6, 9 and 12 fall under moderate landslide hazard zone whereas facets 7, 8, 10, and 11 fall under high hazard zone. The area falling in facets 3, 4 and 5 of Kumuli ghat section fall under high landslide hazard zone, the slope facets 1, 2, 9 and 10 fall in the moderate hazardous zone and other facets in low hazardous zone.

Abstract

Since the landslides have started spreading over to the most of the mountain provinces of all over the world, having developed expertise in Landslide vulnerability mapping, Factor of safety, Rock mechanic studies etc. the scientists and the technocrats have started focusing towards developing landslide early warning systems using instruments. As the instrumentation in such vast areas is not feasible satellite based monitoring of landslide movements is fast emerging. In this connection the paper discusses InSAR interferometry based landslide movements carried out in Nainital and Mansadevi areas, Uttrakhand Himalayas, India.

Keywords: SAR interferometry, Monitoring movements, Nainital & Mansadevi Landslides.

INTRODUCTION

Landslides pose greater threats to the population of India also, especially those living in mountainous regions, the top being the Himalayas. Many villages and vital transport routes are endangered by landslides and losses of lives and important infrastructure now become a routine phenomenon. Therefore, studies on surface displacements and landslide movements have become very important. However, due to the large aerial extent of the landslide prone provinces, this task may not be effectively carried out by ground based methods. In the recent years, the availability of interferometric Synthetic Aperture Radar (InSAR) data from a variety of satellite and airborne remote sensing sensors has emerged, as a potential tool that can yield accurate data on surface displacements. Although, monitoring of such low velocity deformations, as we observe in landslides, is only possible if considerably long time series images are available. InSAR derived displacement measurements are not only feasible but also moderate in their costs compared to many ground-based methods. This paper discusses Small Baseline Subset (SBAS) algorithm used to monitor landslide movements.

Abstract

The landslide is a disaster which causes rampant loss to life, property and ecosystems. With increased awareness and technological development, the number of monitoring stations near hazardous regions have increased. To give warning prior to the occurrence of a landslide, the soil/rock mechanics of the underlying bed needs to be studied and understood. This paper examines the current literature and elucidates some features of state-of- the-art landslide monitoring systems.

Keywords: Field based sensors, Wireless sensor network, Landslide monitoring

INTRODUCTION

Advancements in technology have helped us to understand nature better than before, yet the geotechnical parameters causing landslides could not be quantified accurately. The efforts taken in predicting landslides are clearly moving towards this objective and this can be seen by the number of monitoring stations that have been setup in landslide prone areas around the world. The data that is obtained at each location is important in understanding landslides. Each location is unique in terms of soil properties, groundwater, inclination of the slope and weather conditions and consequently, each deployment is unique.

The paper narrates the instrumentation based forewarning systems functioning around the world. The paper discusses these aspects hierarchically viz; Landslide prone areas in India, geotechnical instrumentations and their merits, influence of rainfall on landslides, correlation between rainfall and pore pressure, the relevance of different systems for different scenarios etc.

Abstract

The article briefly narrates the initiatives taken by the Department of Science and Technology, Govt. of India, New Delhi in providing solutions to rapidly growing Landslide Disasters in India. Duly considering the importance of the issue, the DST has embarked on a National Landslide Programme more than two decades ago and brought voluminous information on Landslide Vulnerability Mapping, Site Specific Landslide Investigations, Landslide Kinematics, Instrument Based Forewarning etc. by funding large number of research projects to various Academic/Research institutions in the country. In addition, the bilateral collaborative programme launched on Geohazards between India & Norway, resulted in bilateral flow of knowledge and capacity building amongst various tiers of the Academic, Research and the Planning Hierarchy, yielding tangible benefits.

Keywords: Landslides in India, DST’s Initiatives.

INTRODUCTION

Landslides cause extensive damages to roads, bridges, human dwellings, agricultural lands, forests and other establishments year after year resulting in immense losses of life and properties. The entire Himalayan region has been the target of intense development activities for the last few decades. Hence the instabilities along the natural slopes are accentuated by the human activities since the development schemes are often not properly planned and implemented (Valdiya 1980; Thakur 2001). This has become the case in most of the mountains in India. Keeping in view of the stability of the slopes, the need of the hour is to achieve sustainable development of the hilly regions while implementing various developmental schemes. So there has to be a major S&T role to play to minimize the landslide problems. This should include all possible corrective and preventive measures to minimize the losses due to this disaster.

Abstract

The state of Nagaland located in the northeastern part of the Indian subcontinent is also prone to landslides similar to the other north eastern states due to the softer lithologies, intense deformation and extensive anthropogenic activities. So in order to understand the landslide vulnerability and to evolve remedial measures, a 12 km stretch of the NH-2 from Kohima town in the south to Zhadima junction in the north was studied. The study comprises the preparation of landslide hazard zonation map using BIS method and detailed studies in six major landslides involving RMR, SMR and Kinematic analysis and also the suitable remedial measures for such landslide phenomenon.