Understanding the role of land use, land cover, and the climate change on the fluoride concentration and groundwater availability in Telangana region, India

Dr Machender Ganaboina

Department of Geology, Mahatma Gandhi University, Anneparthy, Nalgonda (TS) 508254

Professor A.L. Ramanathan

Professor, Jawaharlal Nehru University, New Delhi 110067

Abstract

The main objectives in conducting the present studies are to minimize the cost of investigation and to maximize the results for analyzing and evaluating the quality and availability of groundwater researches. Climate change is “a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods. Climate fluctuations are not unusual. In the North Atlantic Sector, for example, it is well known that the average temperatures and winds can fluctuate on decadal time scales. Climate changes caused by humans (anthropogenic) also evolve over the course of several decades. The natural decadal changes and those caused by humans are therefore superimposed upon one another. This makes it difficult to assess the impact of humans on climate with certainty. And also, proper understanding of the problem (Fluoride) of relation between geology, distribution, it is also proposed to investigate different aspects like land use and land cover, rainfall, climate, evapotranspiration, runoff, infiltration and water level fluctuation. To propose suitable remedial measures to reduce groundwater pollution in the area as well as water quality and availability. Correlation of Social problems of the area. The details of this research paper will also create awareness among the common public as to how to overcome the problems associated with groundwater pollution and remediation of the contaminated sites due to agricultural, industrial activities and urbanization. The Fluoride occurrence in groundwater is a natural phenomenon influenced by the local and regional geological setting. It is unique substance for which there are both lower and upper limits of concentration in drinking water with identified advantages and disadvantages. Granitic rocks contain a relative abundance of fluoride-rich minerals such as micas, apatite and amphiboles etc. Fluorite (CaF₂) is the principal fluoride mineral, mostly present as an accessory mineral in granites. To explore the causes of high fluorides in groundwater and surface water causing a widespread incidence of fluorosis in local population. Groundwater is affected by many factors such as physico-chemical characteristics of soil, rainfall, soil erosion, weathering of rocks, chemical reactions below land surface, role of micro-organism, human and agricultural wastes and industrial effluents. Soils serve as a medium through which groundwater is recharged and any constituent added to soil may adversely affect the quality of groundwater. Anthropogenic and geogenic activities are a major source of metal pollution of soils. Thus, we have proposed scientifically the study area for research work.

Keywords: LU & LC, climate change, fluoride and groundwater

Abbreviations

INTRODUCTION

Objectives of the Proposed Research Work

1. To Understanding the role of land use, land cover, of Telangana region.

2. To study the climate change on the fluoride concentration and groundwater availability in Telangana region.

3. To study of previous samples from different media like groundwater, stream water and tank water (i.e. surface water) and soils of Telangana region.

4. Study about the Structural and Geological control over Groundwater potentials and availability of the area.

5. Ascertain the quality of Groundwater and whether it quality is controlled by agricultural practices or parental material (rocks) or anthropogenic activity.

6. Assess the level of contamination.

7. Ascertain the suitability of water for domestic/irrigation/ industrial purposes.

8. To study the chemistry of water and soils of the area for assessment of environmental monitoring and Propose remedial measures to reduce the groundwater pollution.

9. Migration of the elements into the soils, groundwater, surface water.

METHODOLOGY

1. Collection of literature survey and rainfall data of Telangana State.

2. Preparation of Geomorphological, Geological map of the area.

3. Preparation of Drainage, Land use and Land cover, Slope, Soil Resource, Elevation with Contour maps, Groundwater prospecting maps and Structural maps of Telangana region.

4. To study of previous samples of groundwater, stream water, tank water from pre-to post-monsoons samples in the area.

5. Data processing and analysis was carried out by Softwares like GIS, Surfer, Grapher, Aquachem and SPSS.

6. Interpretation of field geological and structural and laboratory (chemical) data.

7. Organizing research outcome in the form of Report.

STUDY AREA

Telangana is a State in India situated on the centre-south stretch of the Indian peninsula on the high Deccan Plateau (Fig 1). It is the twelfth largest state and the twelfth-most populated state in India with a geographical area of 1,12,077 Sq. Km (43,273 sq mi) and 35,193,978 residents as per 2011 census. On 2 June 2014, The Telangana region was part of the Hyderabad state from Sept 17th 1948 to Nov 1st 1956, until it was merged with Andhra state to form the Andhra Pradesh state. After decades of movement for a separate State, Telangana was created by passing the AP State Reorganization Bill in both houses of Parliament. The area was separated from the northwestern part of Andhra Pradesh as the newly formed 29th state with Hyderabad as its historic permanent capital. Its other major cities include Warangal, Nizamabad, Khammam and Karimnagar. Telangana is bordered by the states of Maharashtra to the north, Chhattisgarh to the east, Karnataka to the west, and Andhra Pradesh to the east and south. The terrain of Telangana region consists mostly of hills, mountain ranges, and thick dense forests distribution of 27,292 sq. km. As of 2019, the state of Telangana is divided into 33 districts (Fig 2 & 3). The “Environment” is a complex system with physical, biological, geological, ecological, and geopolitical aspects. Studying it requires multidisciplinary research (e.g. Environmental geology, environmental chemistry, global climate change, biological diversity and ecosystems, environmental.

Past History of Telangana

Throughout antiquity and the Middle Ages, the region now known as Telangana was ruled by multiple major Indian powers such as the Cholas, Mauryans, Satavahanas, Chalukyas, Kakatiyas, DelhiSultanate, BahmaniSultanate, Golconda Sultanate. During the 16th and 17th centuries, the region was ruled by the Mughals. The region is known for its Ganga- Jamuni Tehzeeb Ganga - Jamuni Tehzeeb. During the 18th century and the Biritish Raj, Telangana was ruled by the Nizam Hyderabd. In 1823, the Nizams lost control over Northern Circars (Coastal India) and Ceded District (Rayalaseema), which were handed over to the East India Company. The annexation by the British of the Northern Circars deprived Hyderabad State, the Nizam's dominion, of the considerable coastline it formerly had, to that of a land locked area princely state with territories in Central Deccan, bounded on all sides by Biritish India. Thereafter, the Northern Circars were governed as part of Madras Presidency until India's independence in 1947, after which the presidency became India's Madras state. The Hyderabad state joined the Union of India in 1948 after an Indian military invation. In 1956, the Hyderabad State was dissolved as part of the linguistic reorganisation of states and Telangana was merged with the Telugu-speaking Andhra Pradesh (part of the Madras Presidency during the British Raj) to form Andhra Pradesh. A peasant-driven movement began to advocate for separation from Andhra Pradesh starting in the early 1950s.

​Economy and IT of Telangana

The economy of Telangana is the eighth- largest state economy in India with ₹8.43 lakh crore (US$120 billion) in gross domestic product and a per capita GDP of ₹181,000 (US$2,600). The state has emerged as a major focus for robust IT software, industry and services sector. The state is also the main administrative centre to a large number of Indian defence aero-space and research labs like Bharath Dynamic limited, Defence metallurgical Research Laboratory, Defence Research and Development Organization and Defence Research and Development Laboratory.

Cultural of Telangana

The cultural hearts of Telangana, Hyderabad, and Warangal, are noted for their wealth and renowned historical structures – Charminar, Qutb Shahi Tombs, Paigah Tombs, Falaknuma Place, Chowmahalla Place, Warangal Fort, Kakatiya Kala Thoranam, Thousand Pillar Temple, Cheruvu gattu, Pedda gattu temple and the Bhongir Fort in Yadadri Bhuvanagiri district. The historic city Goclonda during the Kakatiya reign was once known for the mines that have produced some of the world's most famous gems, including the Koh-i-Noor, Hope Diamond, Daria-i- Noor, Regent Diamond, Nassak Diamond and Noor-ul-Ain. Religious edifices like the Lakshmi Narasimha Swamy Temple in Yadadri Bhuvanagiri district, Makkah Masjid in Hyderabad, and Medak Cathedral are several of its most famous places of worship.

Geographic Location

Telangana is situated largely in an upland region of the Deccan (peninsular India). Much of its surface area is occupied by the Telangana Plateau in the north and the Golconda Plateau in the south and is composed of gneissic rock (gneiss being a foliated rock formed within Earth’s interior under conditions of heat and pressure). The average elevation of the plateau area is about 1,600 feet (500 metres), higher in the west and southwest and sloping downward toward the east and northeast, where it meets the discontinuous line of the Eastern Ghats ranges. Drainage is dominated by the basins of the Godavari River in the north and the Krishna River in the south. As a result of erosion, the topography of the plateau region consists of graded valleys with red sandy soil and isolated hills. Black soil is also found in certain parts of the area.

Fig 1: Location map of Telangana State (Red and black Colour) in India. 

Fig 2: The Administrative Boundaries of Telangana State.

Fig 3: The state of Telangana is divided into 33 districts.

The state is divided into 33 districts (Table 1.) two new districts Mulugu and Narayanpet were formed on 17 Feb 2019, which are further divided into 68 revenue divisions and they are in turn divided into 584 mandals.

Regional Geology

The geology of the area in general comprises of granites and gneisses of Peninsular gneissic complex of Archean age. The terrain around entirely covers mainly of grey and pink granites of Archean, with plains and small mounds of Pre-Cambrian granitoides with small dolerite dykes, pegmatite and quartz intrusions of basic enclaves (Table 2.). The area possesses few outcrops, and therefore, the lithological and structural mapping has to be carried out to understand the geology of the concern basin. The Red, black and loamy soils are the prominent soil horizons in the study area. These soils are developed due to weathering of granitic and mafic rocks. Red soils are present in the dry upland areas while black and loamy soils are developed in water logged areas. The drainage in the area is dendritic type and it is controlled by undulatory topography, geographical location, physiography, climate, rainfall and drainage with a third order streams is predominant in the basin.

Groundwater in granites and gneisses occurs along the weathered and fracture zones. The maximum depth of the weathered zone is about 10-25 feet but majority of the wells that are encountered falling in the depth range of 26-35 feet. The topography characteristics are found to have extensive influence on the groundwater regime. It is found that the deeper wells are capable of sustaining daily pumping for about 4-6 hours. It is found that the position of water table is influenced not only by the rainfall but also controlled by topography, geology, structures and hydrogeological conditions. The groundwater resources can be replenished through construction of percolation tanks, judicious land management and groundwater pattern etc,. Desirable results of water/soil analysis may further decipher about the quality of water.

Hydrogeology

Hydrometeorological information besides being important in groundwater studies plays an important role in various multipurpose projects, agriculture, irrigation, industries, aviation, shipping and fishing atmospheric processes. Jagannadhan and Dhar (1966) discussed the meteorological factors causing floods, their seasonal characteristics and also indicated basic hydrological data necessary for planning, designing and management of various hydrological aspects. Mani et al (1969) dealt with the indigenous design and manufacture of hydrometeorological equipment. Committee for Indian Hydrological Programme has been acting as a Catalyst to promote hydrometeorological studies. Krishna Rao (1971) dealt the status of work related to compilation of various agro climatological factors contributing to groundwater recharge.

Occurrence of Groundwater mainly depends on rainfall and it is the most important factor of Groundwater resource of any area. Rainfall refers to amount of Liquid Precipitation based on intensity and it is categorized into three types i.e., Light, moderate and Heavy. Precipitation is the principal and ultimate Source of Groundwater therefore; its distribution is an important aspect of Groundwater study. Hydrometeorological data delineate the presence of the Groundwater balance in an area. The most useful Hydrometeorological elements are Precipitation, Evaporation, Evapotranspiration, Humidity, Temperature, Soil moisture etc.

Krishna Rao, (1971) stressed importance of Hydrometeorological data in computing Groundwater Potentials. Subramanian, (1979) stated “study of climate is necessary to elevate water balances in an area” Hydrometeorological studies provide better understanding of groundwater resources. Hydrology of the area mainly depends on climatic conditions and geomorphic conditions.

The distribution of groundwater depends on the vertical and lateral extent of rock formations and their nature, weathering, fracturing and interconnected void spaces (Raghava Rao 1969). Though the hydrologist chiefly concerned with the groundwater, however for proper understanding of the relations between geology, distribution and occurrence of groundwater in general way all the aspects of the hydrologic cycle (fig.4) must be understood.

Rainfall

The type, Intensity, frequency, duration and distribution of rainfall and its relation to topography play an important role in groundwater recharge of the area. The Physical, structural features of the rocks and nature of the soil also contribute to the groundwater recharge of the area. Principal source of the groundwater in the region is precipitation. Most of the precipitation in the area is from the southwest monsoon during the months of June to October. Analysis of rainfall data is an important factor of Hydrogeological study. Hydrologic cycle is the circulation of water from Ocean to atmosphere, from there to Lithosphere and Lithosphere to Ocean through complex and independent process including Precipitation, Runoff, Groundwater flow, Evaporation, and Evapotranspiration (Fig 4 & 5.). Thus, Hydrologic cycle determines water resources at all stages. The rainfall data of Bibinagar, Bhongir, Chityal, Narkatpalle, Kattangur, Nakrekal, Tipparti and Vemulapalle mandals.

Fig 4. Hydrological cycle.

Rainfall variation

Rainfall distribution depends not only on terrain conditions but also on topography, soil profile and bed rock geology. Several investigators put their effort on precipitation and elevation relationship. Many geologists have been observed “correlation of mean seasonal precipitation with elevation, Slope, Orientation etc” finally he was concluded that 30% of variation in precipitation occurred is due to elevation difference.

Fig 5. Hydrological Budget map.

Rain-gauge station

The number of gauges necessary to achieve a measurement of the rainfall within the selected confidence limit, can be determined by assuming that the area is meteorologically homogenous, the distribution is normal, and that there are no systematic sampling errors. According to Karanth (1987), has classified rainfall into low, moderate and heavy based on intensity of rainfall (Table 3).

In Telangana some areas we are discussing rainfall example Bibinagar, Bhongir, Chityal, Narkatpalle, Kattangur and Nakrekal mandal (Tables:4 to 14) the rainfall occurs between June and October during the onset of south west monsoon. The humidity is very high and it varies between 60 and 80 % during the monsoon period. The highest rain fall would occur the months from June to September. The area receives an average annual rainfall of 900 mm from the southwest and northeast monsoon in a year. The highest precipitation generally occurs during the southwest monsoon. The intensity and amount of rainfall is unpredictable during the northeast monsoon period (October & November). The cyclonic storms that commonly originate in the Bay of Bengal and are generally affected the normal monsoon.

Table 4. Statistical data of rainfall of the Bibinagar Mandal for the period from year 1989 to 2008 (data from Central and State Groundwater Boards).

Table 5. Statistical data of rainfall of the Bhongir Mandal for the period from year 1988 to 2008 (data from Central and State Groundwater Boards).

Statistical data of rain fall of the Bibinagar and Bhongir mandals of the Telangana region for the periods from 1988 to 2008 is listed in Tables. 4 and 5 and the same data were shown in the Bar diagram or Rain fall charts (Figures.5 a to g and 6 a to f). As per the rain fall data of the area, maximum precipitation takes place during south - west monsoon especially from June to September months.

Figs.6. Bar diagram of rainfall from the Bibinagar Mandal for the periods from 1988 to 2008.

Fig 1

Figs.7. Bar diagram of rainfall from the Bhongir Mandal for the periods from 1988 to 2008.

Fig.8 Hydrographs of Chityal, Narkatpalle,
Kattangur, Nakrekal, Tipparti& Vemulapalle.

Runoff

Runoff is one of the most important parameters in the hydrological cycle. Runoff is the water discharged through streams consisting wholly or in part of water contributed by over land flow and groundwater flow. Runoff is of two types i.e., surface runoff and sub-surface runoff. Surface runoff is that water which travel over the ground surface to the channels and rivers. The subsurface runoff is the laterally moved infiltrated water through the soil layer it enters stream channels. Runoff water includes that part of the precipitation that does not filter through the soil or is lost by evaporation, but runs over the ground surface to reach the outlet of basin. The actual runoff is equal to rainfall minus loss owing to percolation and evapo-transpirations. These losses vary greatly depending upon climatological factors such as precipitation, evaporation, transpiration and location.

The surface runoff in the catchment is mainly controlled by intensity, duration of rainfall, soil conditions, land cover and terrain slope. The land is the critical character, affecting on the hydrological response in the surface hydrologic modelling, specifically, the evapo-transpiration, infiltration, runoff and erosion, aerial distribution of precipitation, humidity and temperature of atmosphere. Geological and topographical conditions and density of precipitation has pronounced opposite effects on the surface and groundwater runoff. High permeability of ground surface, low slope and intensity of precipitation results less surface and more groundwater runoff. The compact soils will make the movement of water easy, permeable soil favours infiltration and reduces the runoff. Regardless permeability of the terrain, if the soil is fully saturated with water, infiltrations will be less and runoff is more. For these factors the amount of runoff in a given area varies from month to month and from season to season. Depending on the type of land and intensity of rainfall, runoff may be of two types i.e., immediate which is produced as soon as water hits the ground and delayed runoff which consists of water that first filters through the soil and then returns to the ground surface. A shower of intensity greater than the intensity of infiltration produces runoff with some water percolating into the ground. In the investigated area North and North-East parts comprise a hill track which is sloping towards the centre portion of the area, where runoff is relatively more than the other parts.

Runoff is a component of precipitation that appears in surface streams of either permanent or intermittent nature. Slope, drainage density, stream distribution are the influencing factors for runoff. Generally runoff is controlled by two factors.

1. Physical characteristics of the area

2. Climate

The physical characteristics are extent of the area, slope and elevation, orientation, soil type and drainage system and finally vegetation etc. The climate and geology also contribute their own share to the runoff process. Distribution of rainfall with its time and directions of stream movement and evapotranspiration. Intensity of flow, duration is one of the important climatic factors of runoff. If the rainfall intensity exceeds then the infiltration capacity will occur.

Infiltration

Infiltration is the passage of water through the soil surface into the ground. It replenishes the soil moisture deficiency and the excess moves downward by force of gravity called percolation and builds up the groundwater table. The maximum rate at which water can enter the soil at a particular point under a given set of conditions is called infiltration capacity and it depends on many factors such as soil type, moisture content, Organic matter, Vegetative cover and season. It is of no use to the crops (except paddy) and it does not help to leach any superfluous salts out to the root zone.

The factors affecting the infiltration are the intensity and duration of rainfall. Rainfall is the main source of recharge for all groundwaters in the area, a study of its incidence, distributions both in space and time, intensity, Variability, frequency etc., is of considerable importance for the study of recharge of groundwater by rainfall. In the absence of availability of data, the effective contribution to groundwater recharge may be taken as one third of the annual rainfall taking away all the losses owing to runoff, evaporation and transpiration (Panduranga Rao, 1974). Of this quantity, perhaps some portions get absorbed in the upper layers, and is also evaporated and lost by evapotranspiration. Approximately, the percentage contribution to the groundwater can be estimated from the available volume of pore space in relation to total annual rainfall minus losses owing to runoff and evapotranspiration. Therefore, the percentage contribution may represent 10 to 15 percent of annual rainfall.

The infiltration rate limited by the transmission capacity of various layers of the soil. The properties of soil such as texture, structure, clay content, porosity and continuity of pores influence the rainfall infiltration. The effect of soil moisture is of two ways. At the beginning of rain, after day and rainfall-less period, the soil will be quite dry and cracked. When rain comes on such soils water infiltrates into the ground through pores and cracks. The rate of infiltration is high at the beginning due to the strong capillary potential created under the surface. After sometime when all the pores in the soil water zone gets filled up with water, then rate of infiltration called the “Saturation infiltration rate” is very much less than the initial infiltration rate. Water infiltrated enters into groundwater table in three stages, First infiltration of water into the soil zone, then into the zone of aeration, lastly reaching of percolated water into the saturated zone. The present study area of granitic terrain it is observed from open well and bore wells, that the area is covered with considerable thickness of soil from few centimeters to 2 meters. The subsoil of morrum (residuum) often comprises a fairly high degree of thickness varying from 10 to 15 meters. Subsoil is underline by weathered, fractured and jointed rocks up to a depth of 40 to 50 meters.

Evapotranspiration

Evaporation and transpiration is an important factor in hydrological cycle. “Evaporation and Transpiration are closely connected to each other; no exact demarcation is possible. Under field conditions it is practically impossible to differentiate between evaporation and transpiration and both are lumped together as Evapotranspiration”. The main factors of Evapotranspiration are solar radiation intensity and duration, relative humidity, wind conditions, clouds altitude and atmospheric pressure. Estimates of evaporation from free water surface and the soil and transpiration from vegetation is of great importance in hydro-meteorological studies. The process of molecules of water at the surface of water soil acquires enough energy through sun radiation to escape the liquid and to pass into the gaseous state. Transpiration is the process by which plants loss water to the atmosphere. These two effects are considered together and known as “evapotranspiration”. Through action of evaporation, transpiration and sublimation a large amount of water is returned to the atmosphere as vapor from water surfaces and enclosed. The rate of evaporation depends on many factors such as temperature, relative humidity, wind velocity, barometric pressure and pollution of water. The rate of evaporation losses under a given set of meteorological conditions differs from one surface to another and types and stages of vegetative growth (Davis and Dewiest, 1966).

The detailed investigation of evaporation losses for various areas in the region are still lacking and exact measurement of evaporation losses is beyond the scope of the present work. The total amount of rainfall over the area as a whole based on the average rainfall per year. In the field tests for the evaporation, generally the evaporation is calculated one third of the precipitation. The evaporation is greatest on flat and barren lands and more in hot weather than in winter and also it varies with the seasons and humidity of atmosphere. Evaporation is nothing but loss of water from any region. It is a natural process from liquid state to gaseous state. About 70% of annual precipitation on the land surface of the earth returns to the atmosphere by way of Evaporation and transpiration. Evaporation and transpiration are the key for the precipitation and precipitation is the important component in Hydrologic cycle. Evaporation depends on availability of water, temperature, humidity, vegetation and wind etc.

CLIMATE CHANGE AND DISASTERS

Climate change is “a change of climate (Fig 9.) which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods." (UNFCC)

Fig 9. Climate change scenario map.

The Earth’s climate is influenced by many factors, including solar radiation, wind, and ocean currents. Researchers try to integrate all of these influencing variables into their models. Many of the processes involved are now well understood. But interaction among the various factors is very complex and numerous questions remain unresolved as we all learned in school, the world’s oceans are one of the most important elements in the global climate system. But what does “climate” actually mean? The difference between weather and climate can be expressed in a single sentence: “Climate is what you expect; weather is what you get.” This reveals a fundamental difference between weather and climate. Weather research is concerned with the formation, movement, and prediction of the individual elements of weather, such as a particular low-pressure system or a hurricane. Climate research, on the other hand, deals with the more comprehensive totality of low-pressure systems and hurricanes, and is dedicated to addressing questions such as how many mid latitudinal storms or hurricanes will occur next year, or whether they will become more frequent or intense in the coming years as a result of global warming. So, the term “weather” refers to short-term events in the atmosphere while “climate” relates to longer time periods. For describing climate, as a rule, a time span of 30 years is generally used as a frame of reference. People mainly perceive climate change as changes in atmospheric variables, for example, variations in temperature or precipitation. In principle, due to its chaotic dynamics, the atmosphere itself can generate many natural climatic changes. One example of this is the North Atlantic oscillation (NAO), which significantly influences the climate over parts of Europe and North America. It is a kind of pressure fluctuation between the Icelandic Low and the Azores High that determines the strength of winter westerly winds across the North Atlantic. If these are strong, the result is mild and rainy weather in Western Europe; if they are weak it is dry and cold. These kinds of natural oscillations make it difficult to recognize anthropogenic climate changes due to an enhanced greenhouse effect. The atmosphere is not an isolated system. It interacts with other components of the Earth system – the oceans, for example. But it is also in contact with the cryosphere (ice and snow), the biosphere (animals and plants), the pedosphere (soil) and the lithosphere (rocks). All of these elements together compose the climate system, whose individual components and processes are connected and influence each other in diverse ways. These components all react to change at different rates. The atmosphere adjusts to the conditions at the Earth’s surface such as ocean temperature or ice cover within a few hours to days. Furthermore, weather is variable and can only be predicted a few days in advance. In fact, it has been shown that the theoretical limit of weather pre while “climate” relates to longer time periods. For describing climate, as a rule, a time span of 30 years is generally used as a frame of reference. People mainly perceive climate change as changes in atmospheric variables, for example, variations in temperature or precipitation. In principle, due to its chaotic dynamics, the atmosphere itself can generate many natural climatic changes. One example of this is the North Atlantic oscillation (NAO), which significantly influences the climate over parts of Europe and North America. It is a kind of pressure fluctuation between the Icelandic Low and the Azores High that determines the strength of winter westerly winds across the North Atlantic. If these are strong, the result is mild and rainy weather in Western Europe; if they are weak it is dry and cold. These kinds of natural oscillations make it difficult to recognize anthropogenic climate changes due to an enhanced greenhouse effect. The atmosphere is not an isolated system. It interacts with other components of the Earth system – the oceans, for example. But it is also in contact with the cryosphere (ice and snow), the biosphere (animals and plants), the pedosphere (soil) and the lithosphere (rocks). All of these elements together compose the climate system, whose individual components and processes are connected and influence each other in diverse ways. These components all react to change at different rates. The atmosphere adjusts to the conditions at the Earth’s surface such as ocean temperature or ice cover within a few hours to days. Furthermore, weather is variable and can only be predicted a few days in advance. In fact, it has been shown that the theoretical limit of weather pre-Climate fluctuations is not unusual. In the North Atlantic Sector, for example, it is well known that the average temperatures and winds can fluctuate on decadal time scales. Climate changes caused by humans (anthropogenic) also evolve over the course of several decades. The natural decadal changes and those caused by humans are therefore superimposed upon one another. This makes it difficult to assess the impact of humans on climate with certainty. In contrast to the dynamic North Atlantic region, the effects of climate change are easier to detect in more stable regions such as the tropical Indian Ocean. There is no doubt that the oceans drive interannual or decadal climate fluctuations. Decadal fluctuations of Atlantic hurricane activity or precipitation in the Sahel correlate remarkably well with oscillations of ocean temperature in the North Atlantic. Although the precise mechanisms behind these decadal changes are not yet fully understood, there is general agreement that variations in the Atlantic overturning circulation play an important role. This hypothesis is also supported by the fact that Atlantic sea surface temperature anomalies occur in cycles of several decades, with a pattern which is characterized by an inter hemispheric dipole. When the rate of northward warm water transport increases, the surface air temperature rises in the North Atlantic and falls in the South Atlantic. If it becomes cooler in the north and warmer in the south, it is an indication of weak ocean currents. The air-temperature difference between the North and South Atlantic is therefore a measure of the overturning circulation strength. Modern climate models can simulate the present-day climate and some historical climate fluctuations reasonably well. These models describe the climate with satisfactory reliability, especially on a global scale. But for smaller geographical areas the models are less.

Long term variation in global temperature, the geologic record shows a wide range of variation in global temperature (Fig 10.) on a variety of scales. Radiative forcing due to a variety of causes has been postulated for many extreme climatic events. Tertiary and Quaternary periods have experienced wide fluctuations over relatively short spans of time with overall cooling towards the present. The Quaternary is characterized by repeated continental glaciation. The Cretaceous Period was the warmest time in all of geological history (average global temperature is estimated to have been 20 degrees C).

Fig 10. Climate change Over Geologic Time scale

The world oceans, global climate drivers reliable. It is much easier to infer the globally averaged temperature than to predict the future precipitation in Berlin. Extensive measurement series are required to better understand regional climate. For many regions of the Earth, in the Southern Ocean for example, there are long time periods in the past with only a limited number of measurements. Today data are provided in these areas by satellites. Many mathematical models now exist that can help to understand the impacts of human activity on climate. As one aspect, they simulate climate response to external natural and anthropogenic forcing, but they also reveal how climate interacts with the biogeochemical cycles such as the carbon cycle. Climate research is thus developing into a more comprehensive study of the Earth system, and today’s climate models are evolving into Earth system models. This is necessary in order to study the multiple interactions. For example, the impact of global warming on the stratospheric ozone layer can only be investigated when the chemical processes in the atmosphere are taken into account. Another example is acidification of the seawater due to uptake of anthropogenic CO₂ by the ocean. No one has yet been able to predict how the warming and acidification of the ocean will influence its future uptake of anthropogenic carbon dioxide, upon which the carbon dioxide levels in the atmosphere and thus the future temperature change depends. There is a mutual interaction between the ocean and the atmosphere. To a large extent the ocean determines the intensity of climate change, and its regional expression in particular. On average, warming is taking place globally. But individual regions, such as the area of the Gulf Stream, may behave in different ways. On the other hand, the ocean itself reacts to climate change. Understanding this complex interplay is a task that will take years to accomplish.

Natural Hazard “When a natural process poses a threat to human life or property; we call it a natural hazard”. Disaster “may be defines as a serious disruption of the functioning of a community or a society causing widespread human, material, economic or environmental losses which exceed the ability of the affected community or society to cope using its own resources” (Table 15.).

Disaster Risk = function (Hazard, Exposure, Vulnerability)

Disasters

1) Natural

2) Man made

Table 15. Classification of Natural disasters.

Atmosphere

Volatile turbulent fluid, strong winds, Chaotic weather, clouds, water vapor feedback Transports heat, moisture, materials etc. Heat capacity equivalent to 3.2 m of ocean. In geological terms, “short-term” refers to hundreds to thousands of years, Variation in greenhouse gases accounts for some variation in global temperature (Fig 11.). Variation in incoming solar radiation also accounts for some of the global temperature change Over the past 155 years the Earth’s temperature has increased by 0.8 degrees C. Prior to 1800 temperatures were low (Fig.12) (known as the Little Ice Age).

Fig 11. Global Air Temperature map.

Fig 12. Climate change scenario map.

Ocean

The oceans cover around 70 per cent of the Earth’s surface. They play an important role in the Earth’s climate and in global warming. One important function of the oceans is to transport heat from the tropics to higher latitudes. They respond very slowly to changes in the atmosphere. Beside heat, they take up large amounts of the carbon dioxide emitted by humankind. 70% of Earth, wet, fluid, high heat capacity Stores, moves heat, fresh water, gases, chemicals, Adds delay of 10 to 100 years to response time. The oceans cover 70.8% of the Earth’s surface (Table 16.). The oceans are wet: water vapor from the surface provides source for rainfall and thus latent heat energy to the atmosphere. The heat capacity of the atmosphere is equivalent to that of 3.5 m of ocean. The oceans slowly adjust to climate changes and can sequester heat for years. The ocean is well mixed to about 20 m depth in summer and over 100 m in winter. An overall average of 90 m would delay climate response by 6 years. Total ocean: mean depth 3800 m. Would add delay of 230 years if rapidly mixed. In reality, the response depends on rate of ventilation of water through the thermocline (vertical mixing). Estimate of delay overall is 10 to 100 years. The ocean currents redistribute heat, fresh water, and dissolved chemicals around the globe.

Role of Land

Small heat capacity, small mass involved (conduction) Water storage varies: affects sensible vs latent fluxes, Wide variety of features, slopes, vegetation, soils, Mixture of natural and managed, Vital in carbon and water cycles, ecosystems. Heat penetration into land with annual cycle is ~2 m. Heat capacity of land is much less than water: Specific heat of land 4½ less than sea water, for moist soil maybe factor of 2, Land plays lesser role than oceans in storing heat. Consequently, the Surface air temperature changes over land are large and occur much faster than over the oceans. Heat penetration into land with annual cycle is ~2 m. Heat capacity of land is much less than water: Specific heat of land 4½ less than sea water, For moist soil maybe factor of 2, Land plays lesser role than oceans in storing heat. Consequently: Surface air temperature changes over land are large and occur much faster than over the oceans. soils, vegetation, slopes, water capacity. Land systems are highly heterogeneous and on small spatial scales. Changes in soil moisture affect disposition of heat: rise in temperature versus evaporation. Changes in land and vegetation affect climate through albedo, roughness and evapotranspiration. Land has enormous variety of features: topography, Soils, vegetation, slopes, water capacity. Land systems are highly heterogeneous and on small spatial scales. Changes in soil moisture affect disposition of heat: rise in temperature versus evaporation. Changes in land and vegetation affect climate through albedo, roughness and evapotranspiration.

The Role of ICE

Major ice sheets, e.g., Antarctica and Greenland. Penetration of heat occurs primarily through conduction. The mass involved in changes from year to year is small but important on century time scales. Unlike land, ice melts Þ changes in sea level on longer time-scales. Ice volumes: 28,000,000 km³ water is in ice sheets, ice caps and glaciers. Most is in the Antarctic ice sheet which, if melted, would increase sea level by ~65 m, vs Greenland 7 m and the other glaciers and ice caps 0.35 m. In Arctic: sea ice ~ 3-4 m thick and Around Antarctic: ~ 1-2 m thick, Huge heat capacity, long time scales (conduction), High albedo: ice-albedo feedback Fresh water, changes sea level, Antarctica 65 m (WAIS 4-6m), Greenland,7m, other glaciers 0.35m.

The Role of the Atmosphere in Energy

The atmosphere is the most volatile component of climate system, Winds in jet streams exceed 100 mph or even 200 mph; winds move energy around. Thin envelope around planet 90% within 10 miles of surface 1/400^th of the radius of Earth; clouds appear to hug the surface from space. The atmosphere does not have much heat capacity. “Weather” occurs in troposphere (lowest part) Weather systems: cyclones, anticyclones, cold and warm fronts tropical storms/hurricanes move heat around: mostly upwards and pole wards.

Fig 13a. Disaster map of Drought

Fig 13b. Disaster map of Tropical cyclones

Fig 13c. Disaster map of GLOF (Glacial Lake Outburst Flooding)

Fig 13d. Disaster map of Floods

FLUORIDE

The Agriculture and domestic purposes In Chinnaeru River Basin, Nalgonda District, Telangana State. The problem is raised on water quality for human beings, International and National scientific organization like World Health Organization (WHO), Central Groundwater Board (CGWB) raised problem (Reddy A G S et al., 2010) and (WHO 1984, 1996 & 2004), Nalgonda District is one of the poorest and most drought-prone districts of Telangana State in Southern India. The area has been associated with high groundwater pollution (fluoride) concentrations which have been reported to reach up to 10 mg/l (Ram Mohan, et al., 1993). Thousands of inhabitants suffering from paralysis bone diseases, deformities of vertebrae, hands and legs, deformed teeth, blindness and other conditions are common manifestations of this natural hazard in the district. The first fluorosis problem in Nalgonda district was reported (Siddiqui, 1968). There is an urgent need to make professional and scientific assessment of degree of soil and groundwater contamination, define the sources of contamination, the impact on the human health and specify remedial measures. Therefore, the study will help to understand the processes acting in the study area and the controlling factors. It will also help to access the level of contamination and to mitigate the existing problem. The details of this research study will also create awareness among the common public as to how to overcome the problems associated with fluoride, groundwater, soil pollution and remediation of the contaminated sites due to industrial activities, agriculture and urbanization. The primary objective of the study is to ascertain whether groundwater quality is controlled by Municipal wastage (anthropogenic) or litho types (rocks) or both. The study will help to identify the problems and potential of the area to generate a water resource database for overall development on a sustainable basis. In this regard harvesting of water resource judiciously in a smaller hydrological unit has the prime importance. Thus, the right mix of technology and traditional wisdom would be a winning combination, a plan that integrate- mega projects with micro efforts like rain harvesting and watershed management many give scientific solution for the development of backward areas. National and International levelThe groundwater/surface water, not only with similar chemical composition or ionic make up but also within the watershed or sub-basin, has different degree of fluoride concentration; the reasons for this discreet fluoride absorption could be delineated by attempting a comprehensive study of analytic results, which may open up new ideas for understanding more clearly the water-rock interaction contact chemistry. The geochemistry of groundwater has evaluated in Viappar river basin, Tamil Nadu, by adopting various methods like Gibbs plots, Kelley’s index, chloroalkali indices (CAI) and concluded host rock as the main source of dissolved solids in the groundwater (Pandian & Shankar, 2007). The Nalgonda district in South India is well known for high concentration of fluoride in groundwater (Ram Mohan, 1991). (Reddy A G S et al., 2010) Prevalence of fluorosis disease is rampant among majority of rural habitations of the district where groundwater is the only source for drinking and irrigation requirements. International The study has been carried out with the objective to find out the causes of pollution and its impact on human society. Vicinity of many agricultural zones leads to high level of metal toxicity that is derived from the poorly treated wastages on the open land. The study was under taken on Water Quality. Determine the extent and distribution of Fluoride, Nitrates etc., to delineate the source as geogenic or anthropogenic. Fluoride in drinking water has now become one of the most important geo-environmental and toxicological issues in the world. Fluoride has considerable physiological importance for man and animals.

The major health problems caused by fluoride are teeth mottling, skeletal fluorosis, thyroxine changes, kidney damage and deformation of bones in children as well as adults (Grandjean, et al., 1992; Handa, 1988; Jain, et al., 1999; Kundu, et al., 2001; Saxena & Ahmed, 2001; Subba Rao, 2003; Subba Rao, et al., 1998a, 1998b) due to ingestion of high fluoride concentration drinking water for a long-term are well known diseases. Highfluoride in groundwater and surface water have been reported from many parts of the world, particularly in arid and semi-arid areas of India, China, Sri Lanka, Spain, Mexico and many countries in Africa, Western USA and South America (Abu Rukah & Alsokhny, 2004; Ayoob & Gupta, 2006).

The scope of the present study encompasses zones of pollutants to areas of the basin and compares the basin results of the area with those of adjacent basin for regional outlook on groundwater quality, availability and distribution.

 Land Use and Land Cover

Fig14. Land use and land cover
Map of Telangana state. 

Fig15.  Soil Resource Map
of Telangana state. 

Fig 16.  Elevation with Contour Map of Telangana state 

Fig 17.  Groundwater Prospects Map of Telangana state 

Fig 18.  Telangana State Satellite Imagery. 

GEOMORPHOLOGY

Geomorphology has been characterized as the earth shape science, which is concerned with the form of the earth. During recent past the application of geomorphologic studies has been carried out much significance both in exploration of groundwater and mineral resources. For proper assessment of both surface as well as groundwater resources it is widely acknowledged that catchment approach gives the best results as in most cases the surface water basin groundwater basin are concurrent. Morphometry is the measurement and mathematical analysis of the configuration of the earth’s surface, shape and dimensions of its landforms (Chorley, 1953). Evaluation of the characteristics of the drainage network of a basin using quantitative morphometric analysis can give information about the hydrological nature of the rocks exposed within the drainage basin. A drainage map of a basin provides a reliable index of the permeability of the rocks and also gives an indication of yield of a basin. The geometry of a basin plays an important role in evolving quantitative parameters like, linear, areal and relief aspects of a basin.

The quantitative geomorphic methods involve means of measuring size and properties of drainage basin. According to Strahler (1952), the two general classes are: 1. Linear Scale measurements 2. Dimensionless measurements. The descriptive study of a basin involves all those process that in one way or other cause changes in the earth features. From hydrologic point of view the most important of these processes in river erosion which could be considered as having two phases namely, removal of rock and rock accumulation.

Fig 18:  Geomorphology map of Rangareddy District.

Land Use and Land Cover

Fig 19:  Land use and Land cover map of Rangareddy District.

SUMMARY AND CONCLUSIONS

1.     The Telangana region State it covers an area of 1,12,077 sq.km, and falls in the Toposheet No.56.

2.     The lithology of area is mainly made-up of granitic rocks (grey and pink granites, granite migmatite gneisses) of the granite-granodiorite-tonalite (GGT) in composition.

3.     The area belongs to a part of Eastern Dharwar craton of Pre-Cambrian age and is tectonically uplifted and deformed during Neo-Proterozoic period by the younger tecto no-thermal activity in the form of wide spread dolerite dyke swarms, younger granitoids, granulites and gabbroic rocks with widespread fracture system.

4.     Field and petrographic studies of the rocks suggest that they are metamorphosed and deformed at upper amphibolites facies conditions.

5.     The study area comes under semi-arid region and the average rainfall of the study area is 658.1mm/annum. The study area receives maximum rainfall in South - West monsoon period i.e., 70 %. The type, intensity, frequency, duration and distribution of rainfall and its relation to topography play an important role in groundwater recharge of the area. Most of the precipitation in the area is from the southwest monsoon during the months of June to October.

6.     The study of the drainage pattern and geomorphology of the research area the following conclusions can be drawn, Drainage pattern observed in the area is of dendritic to sub dendritic type, which is a characteristic of the granitic terrain. Most of the channels drained themselves into Musi River which is a major surface resource. The drainage pattern in the Telangana region is dendritic to sub-dendritic type. Its dendrite pattern is the characteristic feature in the granite terrain. In this pattern, the tributary streams come from all directions to meet main rivers. The drainage pattern in the area is well integrated, five to coarse textured and well oriented at places.

7.     The analysis of drainage pattern in the study area reveals the structure of drainage as dendritic to sub-dendritic. The basin has a stream frequency of 1.2 and it helps in distinguishing the groundwater recharge characteristics in the river basin.

8.     The Fluoride (F^-) concentration varies from 0.4 -2.9 mg/l and 0.6-3.6 mg/l in groundwater during pre-and post-monsoons in some samples of Telangana region respectively. The fluoride content shows a little seasonal fluctuation from pre- to post-monsoon periods. It seems that it is relatively higher in post-monsoon period when compared to the pre-monsoon. 61% groundwater samples in pre-monsoon and 57% groundwater samples in post-monsoon have < 1.5 ppm and therefore these groundwater samples are good for human beings. However, a few groundwater samples contain > 1.5 ppm fluoride at Nymathpalli (3.6), Nagireddypalli (3.3), Bollepalli (3.3) in the south and Pagidipalli (2.7) in the north of the basin. The average F^- content (1.61) in the study area is far less than that of wailapalli in Nalgonda district (Sugreeva reddy et al., 2010) where people are affected by fluorosis due to high fluoride content (avg.2.96).

9.     The water–rock interaction and evapo–transpiration and atmospheric precipitation and arid to semi–arid climatic conditions are played major role in the in groundwater of Fluoride concentration. Due to invasion of Musi river floods which carries lot of organic material and human waste of the Hyderabad city.

REFERENCES

1. Arthus N Strahler., 1957, Quantitative analysis of watershed Geomorphology, American Geophysical Union, Vol.6, PP-913 -920.

2. Broscol, A.J.1959, Quantative analysis of Longitudinal Stream Profiles of Small Water Sheds:Project NR, 389-042. Tech. Report. 18, Columbia Univ.Dept. of Geol. ONR, Geography Br. New York.

3. Carlston, C.W., 1963. Drainage density and stream flow. V.S. Geol. Surv. Prof.paper 422-C, PP.1-8.

4. Chorley, R.J. Malm Donald, E.G and Pogorzelski, H.A 1957. A new standard for estimating drainage basin shape, AM.J. Sci. Vol.255, PP. 138-141.

5. Chorley, R.J., 1953. Climate and morphometry. J. Geol. Vol.65, PP. 628-638.

6. Glock, W.S., 1931. The development of drainage systems, Synoptic views. Geog. Rev.21(3), PP.475-482.

7. Horton, R.E., 1932. Drainage basin characteristics. Trans. Am. Geophysics Union, Vol. 13 PP. 350-361.

8. Miller, V.C., 1953. A Quantitative geomorphic study of drainage basin characterizing in the Clinth Mountain Area, Virginia and Tennessee. Project NR 389-042. Tech. rept. 3, Columbia Univ. Dept. of Geol. ONR, Geography Br., New York.

9. Ravindra.V., 1981.Hydrogeological investigations of Kalvar river basin, Hyderabad. Urban and R.R. districts, A.P., Ph.D Thesis submitted to O.U. Hyderabad.

10. Schumm, S.A., 1956. Evolution of drainage systems and slopes in Bad lands at Perth Amboy, New Jercy, Geol. Soc. Ane. Bull. 67, PP. 597-646.

11. Strahler, A.U., 1952. Dynamic basis of geomorphology – Geol.Soc. Amer. Bull. 63, 923-38 in drainage basin Form and process by K.J. Gregory and D.E. Walling, Pub. Edward Arnold. (1973).

12. Strahler, A.U., 1952. Dynamic basis of geomorphology – Geol.Soc. Amer. Bull. 63, 923-38 in drainage basin Form and process by K.J. Gregory and D.E. Walling, Pub. Edward Arnold. (1973).

13. Todd, D.K., 1959, Groundwater Hydrology, John Wiley and Sons, Inc. New York.

14. Wisler, C.O., Brater, E.F., 1959. Hydrology, John Wiley & Sons, Inc., New York.

15. Davis, S.N., and De Wiest, R.J.M., 1967. Hydrogeology, John Willey and Sons, Inc 2^ndEdn., 463 P.

16. Indian Meteorological Department, 1997 – Report of the Planning Commission.Govt., Of India.

17. Jagannadhan, P., and Dhar, O.N., 1966. The role of hydrometrology in Indian economy.Symp.Water Resources in India.Jr. Indian Geoscience Association.

18. Karanth, K.R., 1987. Groundwater Assessment Development and Management. Tata McGraw-Hill Publishing Company Ltd., New Delhi.

19. Krishna Rao, P.R., 1971. Hydrometeorological aspects of estimating groundwater potential in hard rock areas of Inda. Seminar Volume, Banglore, PP. 1-11.

20. PandurangaRao, M., 1974.Hydrogeological investigations and aquifier characteristics of tubewells in granitic terrain. Ph.D. Thesis, submitted to Osmania University, Hyderabad.

21. RaghavaRao, K.V., 1969. An estimation of the groundwater potential of India – First approximation. Invited speech at the “Soil and Water Management Symposium” at Hissar, Haryana.

22. Subramanyam, K.M., 1979. Groundwater resources.Water resources and their utilization in Andhrapradesh.A.P. Agricultural Univ. PP. 19 – 28.

ACKNOWLEDGEMENTS

It gives me a great pleasure to complete my research work under the supervision of Prof. A.L. Ramanathan, School of Environmental science, Jawaharlal Nehru University, New Delhi. I am extremely grateful to Prof. A.L. Ramanathan for his valuable guidance, constant encouragement and useful discussion, and is particularly indebted to him for a critical review of the manuscript.

Working in the field and laboratory would not have been possible without the cooperation of Shyam Ranjan, and Mr. Naveeen, to whom I am thankful, highly thank ful.

I am grateful to Honrable Vice-Chancellor, Professor. Khaja Althaf Hussain, Registrar, professor. M. Yadhagiri, Principal, Upender Reddy, University College of Science and Informatic, Mahathma Gandhi University, Nalgonda, for their help to get this opportunity.

I express my thanks to Director, Chairman of IAS, INSA and NAS and Mr C S Ravikumar, Coordinator of Science education Programme, Indian Academy of Sciences, Bengaluru, for providing this opportunity of Summer Research Fellowship Programme.

Thanks are due to my research colleagues and senior research fellows in the School of Environmental science, Jawaharlal Nehru University, New Delhi, for their support and best wishes.

Last but not the least I would like to express my deep sense of gratitude to my parents and sisters, for providing encouragement and motivation during my summer research fellowship work.