Errors in levelling and it's solutions

Errors in Levelling

• Errors  in  Levelling  will always occur,  and may be  minor  to  the  point  of  being insignificant or  significant enough  to  warrant adjustment.  Errors in levelling come  from three main  sources: 

1. Instrumental  Errors

2. Personal  Errors

3.  Environmental Errors

 Common errors are listed below, under these headings. 

 Instrumental Errors

• Instrument not adjusted Staff not vertical Staff not standardised - worn at the base  or at the joins 

Personal Errors

• Incorrect readings

•  Incorrect  bookings
•  Incorrect addition - the three checks not applied 
• Bubble not centred before  each reading Parallax not eliminated 
• Staff not vertical 
• Staff not fully  extended
•  Poor change  point - staff settles into ground
•  Poor instrument station - tripod settles into the ground 

Environmental Errors 

• Wind  -  strong wind  causes the instrument to vibrate  and  makes the staff unsteady.
• Temperature  - heat may  cause a  shimmering  effect at ground level near base  of staff and make accurate sightings  difficult. These types  of errors may  be categorised under the  headings ‘gross,  systematic or random’. 

Gross Errors 

These are  often caused  by the observer or  staff-person and are due  to carelessness,  inexperience  or fatigue.   They are  shown listed  under the  heading `Personal Errors'.

Systematic Errors

 These are often due to the  instrumental  defects  listed  under `Instrumental Errors'.   The most important of these is the  collimation error where the  whole error for a single shot (intermediate) is carried  over  into the staff reading.    As  previously noted, equalising the lengths  of backsights  and foresights  eliminates the error.   In situations  where  a large number  of  intermediate  sights  are made, for example building  sites,  then the two peg test should be regularly carried out.
The  non-verticality of the  staff will  also  cause incorrect  readings.   Any  circular bubble used in conjunction  with the  staff should be checked  periodically against a plumbline and adjusted if necessary.

 Random Errors 

These  are  due mainly to  environmental  conditions with  resulting small  errors which tend to  be compensatory.  Extreme wind or  temperature can cause errors.   In windy weather  shelter the instrument,  if  possible, and  keep  sights and the  staff short.  In hot sun reduce  the length of  the sights, keeping  them  at least 0.5  m above ground  level to minimise the effects of refraction.

Sources of Error 

1. The main source of error  is the residual collimation  error of the  instrument.   From  the  two  peg  test  it should  be apparent that  this  error would  be  eliminated by  equalising the lengths  of the  backsight and foresight distances.
2. The staff not  held  vertical.  Fitting  a staff  bubble  to  the  staff, or  by  swaying  the staff backwards and  forwards in  the  direction of  the  level until a  minimum reading  is obtained  eliminates this  error.
3.  An error  in  reading  the staff. This  is minimised by  reducing  the  length of sight so that  the  readings are  easily defined.
4.  The staff moving off  the position at  a change point  when it is  turned  to face  the new instrument setting. Using a change  plate on soft  ground or clearly marking the  change  point on  hard  ground  eliminates  this  error.
5. The instrument settling in soft ground. Setting up on  firm ground,  pushing  the tripod  legs  well into  the  ground and avoiding excessive movement  about  the instrument, eliminates  this  error. 
6. Errors due  to refraction  from warm layers  of air at  ground  level. This  is minimised  by  keeping  readings at  least 1m  above  the  ground.
7.  Errors due  to  the  staff not being  fully extended.  This may be  due either  to carelessness on the  staff man’s  part  or  to  wear  on  the  joints or  retaining  spring. 
8. Finally,  it is  important  to  eliminate  parallax in  the  instrument  by  bringing  the cross hairs  into sharp  focus  using  the eye-piece  focusing  screw.  The  procedure should  always  be  carried  out before  commencing  any reading  to  a  staff. 

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How levelling is worked |Introduction &Types

Introduction to Levelling. 

Levelling  is the process of determining  the difference  in elevation between  two or more points  on the earth's  surface.   It is  of particular importance  to engineering works,  both  in  the  design  stages and  during construction operations.

Methods of obtaining difference of height

   There are many different ways of  obtaining differences  in height.

Spirit Levelling 

Spirit levelling is any of levelling  that  uses  a spirit  level (bubble), similar  to  the bubble  in a carpenter’s level, as part of  the procedure.  It is  the  term  usually applied to  the  traditional use  of  level and  staff  in  obtaining differences in  height.
The  term Differential  Levelling  is  also  used to  describe the  same  process. The  telescope of  a  level provides a  horizontal  line (line of  collimation  or a  line  of sight). The  height  of  points  are determined by  measuring downwards  from  this  line, by sighting  on  to  a  graduated staff held  on  each  point in  turn.  

Barometric Heighting 

Barometric Heighting  is the determination of  differences in height  based on  the premise that  atmospheric pressure  decreases as altitude increases. The difference in atmospheric pressure is  obtained  by  using an  aneroid barometer.   This method  is suitable for exploratory  surveys  where  portability, compactness and time  are important  considerations, and a high degree of  accuracy is not required, although careful observation  can  obtain  results  of  the order  of  ±0.1m. 

Trigonometrical Heighting 

Trigonometrical heighting  is  the determination of  difference in  height  by  measuring vertical  angles and distances. The term  often relates to long sights where allowance must be made for the curvature of  the  earth. To obtain an accurate difference in height between  the two points, it  is essential that  both  the distance and the vertical angle is measured from both  the observation  station  to the  target  station and from the target  station  to  the  observation  station. 

Electronic Levelling

 This is a general  term used to describe  not so much  the method, but  the  type  of equipment used. It includes  alignment lasers,  rotating  head  lasers and digital readout levels.

1. Level line:  A level line is a line lying in a level surface. It is therefore to the plumb line at all the points. 

2. Horizontal plane:  Horizontal plane through a point is a plane tangential to the level surface at that point. 

3. Horizontal line: It is a straight line tangential to the level line at a point 

4. Vertical line: It is the line normal to the level line at a point . 

5. Datum: Datum is any surface ro which elevation are referred. The mean sea level affords a convenient datum world over, and elevation are commonly given as so much above or below sea level. It is often more convenient however, to assume some other datum,  specially if only the relative elevations of points are required. 

6. Elevation: The elevation of a point on or near the earth surface of the earth is its vertical distance above or below an arbitrarily assumed level surface or datum. The difference in elevation between two points is the vertical distance between the two level surfaces in which the two points lie. 

7. Vertical Angle: is the angle between two intersecting lines in a vertical plane. Generally one of these  lines is horizontal. 

8. Mean Sea Level : Mean sea level is the average height of the sea for all stages of the tides. At any particular place it is derived by averaging the hourly tide heights over along period of 19 years.

The  Level 

The level is the instrument  used to obtain  height  differences of  points above  or below  a horizontal  line.  If  this horizontal  line  is  at  a  known height  with respect  to  a known datum, then  the reduced level of  points may be determined.  Although  the  fundamental principle of  a levelling  instrument  is  to establish  a horizontal line, accuracy  requirements  vary widely.  

For this reason  many  different types of  levels have been  designed, each  of which provides optimum performance within its  given accuracy classification. 

Levels are  essentially a  telescope, with  a compensator for  setting  a line of  sight horizontally.   It will  provide  a magnification of  the  levelling staff graduations, and at the  same  time  it  must  be  free  of  parallax. 

Types of Levels

 1. Dumpy  levels 

2. Tilting  levels 

3. Automatic  levels
The dumpy level originally designed by Gravatt, consist of a telescope tube firmly secured in two collars fixed by adjusting screws to the stages carried by the vertical spindle. The modern dumpy level has the telescope  and vertical spindle cast in one piece and a long bubble tube is attached to the top of the telescope. This form  is known  as solid dumpy. 

 Both Dumpy  and Tilting  levels have  the  line  of  collimation (sight) set horizontal  by means of  a  levelling  tube  (bubble).  This will  set the  line  of sight at  90°  to  the  vertical axis ie  to  the  direction  of  gravity. 

Automatic levels will still produce a horizontal  line of  sight if the telescope is almost horizontal which will put it in  the range of  the compensator.  To level these instruments,  the  vertical  axis  is  set  vertical  by centring  the circular  bubble.

Cross hairs. 

When sighting through the telescope of a level the observer will see one vertical cross hair and usually three horizontal crosshairs. 

 The long central horizontal  crosshair is the crosshair used to obtain  a reading  from the  staff  during  levelling.  The  two smaller  horizontal crosshairs are called  stadia  lines and  are used by  a  surveyor to measure the distance  between the  level and  the staff.

 Parallax 

With  all optical instruments,  the  image of  the target  must  be  sharply focused on  the crosshairs  before  any observations are  made.  If  this  is not so, parallax will occur, and could  result  in  staff readings  being  taken which  are  not  the  ‘true’ readings.  The phenomenon of parallax can be observed when  the observer's  head is moved   up or  down  or from side  to  side when looking  through  the  eyepiece,  and  the crosshairs appear to move  with respect to  the image behind  them.  Accurate sighting is therefore  impossible. The diagram  below shows parallax as the target  image is formed slightly in  front  of the  crosshairs (it could  also  be  formed  behind  the  crosshairStaff.

Other Equipment  

1. Levelling Staff:
  The Levelling Staff may be rigid, telescopic or hinged, and is usually made of metal or fibreglass. Most are either 3m or 5m in length when extended.   It is essential that a staff has a solid ‘foot’ or base.   A staff must have some provision for attachment of a levelling bubble to ensure that the staff is held vertical.    There are two types in common use:
 i. Direct reading staff with 5mm graduations.
ii. The 'E' type, with 10mm graduations and alternate metre graduations in black and red.
2. Change  Plates
 Change Plates  are  used to provide a solid base upon  which to place the foot of  the staff when in soft ground such as on grass or sand, or on smooth, hard surfaces, such as  concrete. They  may be  of  two  types:

•   A long spike with  a  metal plate on  top
•   A triangular  plate  with  small feet  to  push  into  the  ground. In both cases a raised  centre  section  to  place  the foot of  the  staff on  is  necessary. 

3. Staff  Bubble
 Since  a  vertical distance is  required,  it  is  necessary to  hold  the staff vertically. The staff  bubble assists  the staff  person to  hold the  staff vertical. It consists  of  a circular bubble and stock  and  is  held against  the side of the staff.

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What is Surveying |introduction ,defination. History of survey in ancient

INTRODUCTION

Definition

 Surveying is  the process  of determining  the relative position  of natural and manmade features  on or under the earth’s surface, the presentation of this information either  graphically in the form of plans  or  numerically in  the form of  tables, and the setting out  of measurements on the earth’s  surface.  It usually involves measurement, calculations, the production of plans, and the determination of specific locations.

 The  surveyor  may be  called on  to determine heights and  distances; to set out buildings, bridges and  roadways; to determine  areas  and volumes and to draw plans at a predetermined  scale.

Types

There are two major  categories  of surveying: 

1. Plane Surveying . 

Plane  surveying deals  with  areas of limited extent and  it is assumed that the earth’s  surface is  a plane and therefore no corrections necessary for the earth’s  curvature.

2. Geodetic Surveying.

 Geodetic surveying  is concerned  with  determining the size  and  shape of the earth and it also provides  a high-accuracy framework for the control of lower order surveys.  The highest  standards  of accuracy are  necessary. Geodetic surveys cover relatively large areas  (eg a state or  country) for which the effects of earth curvature must be considered.

Branches

1. Topographic  Surveys are  concerned with the measurement and  mapping of the physical features  of the earth. These features  are all natural  and manmade features.
2.Engineering Surveys cover  surveys  carried out as  part  of the preparation for, and  carrying  out of, engineering works,  including  roads, railways, pipelines, drainage etc.
3. Cadastral  Surveys are concerned  with the measurement, definition and mapping  and  recording of property boundaries.
4. Hydrographic Surveys are those  made  for determining the  shape  of the bottom of lakes, rivers,  harbours and oceans. They also include the measurement  of the flow  of water in  streams and the estimation  of  water resources.
5. Aerial Surveys are made  from an aeroplane, and for the purpose of  mapping the terrain.  The  control for such  a  map  is obtained  from ground  surveys,  but the details  are obtained  from aerial  photographs.  This includes making measurements and interpretations from aerial photographs.
6. Astronomic Surveys are surveys made  to determine  the latitude, longitude and azimuth from observations to the stars.
7. Mining Surveys are those made to  determine  survey  control for the development  of both surface and underground mines  within the mining industry, and the determination of volumes in mine production.
8. Computing is  a specialised area of  surveying  where complex  computer programs  are  used to solve problems within the surveying industry.
9. Consulting  is  another specialised  area of  surveying where  specialist surveyors are hired for a  short period  of time to advise on the  requirements for a specific  task  or to perform the specific surveying

History of surveying

• It is quite probable that surveying had  its origins in ancient Egypt. The Great Pyramid of Khufu at Giza  was built  c.  2700 BC, 755  feet long and  480 feet high. Its nearly perfect squareness and north-south orientation affirm the ancient Egyptians'  command of surveying.  
• Evidence  of  some  form  of  boundary  surveying as early  as  1400  BC has  been found in the fertile valleys and plains  of the 
• The Egyptians had the groma, which  was used to  establish  right angles. It was made  of a  horizontal wooden cross,  pivoted at the  middle and  supported from above. From  the end of  each  of the  four  arms  hung  a  plumb bob.  A plumb  bob  is a  shaped weight  that hangs  from a string.  Because  of  the  weight, the string  will always  be vertical. 
• The  Greeks  used a  form  of log line for recording the distances  run from point  to point along the  coast while making  their  slow  voyages from  the Indus to the Persian Gulf  about 325 BC.  
• The  Greeks  introduced the astrolabe,  which is  an instrument to  measure the altitude of stars  above the horizon, in the 2nd  century BC. It took the form  of a graduated  arc  suspended  from  a  hand-held  cord. A  pivoted  pointer that  moved over the graduations  was pointed at the  star. The  instrument was not used  for nautical surveying for several centuries, remaining a scientific aid  only. 
•  During their occupation  of Egypt,  the Romans acquired Egyptian surveying instruments, which they improved  slightly  and to which they added  the water level and the plane  table. 
•  About 15 BC  the Roman architect and engineer Vitruvius mounted  a large  wheel of known circumference in a small frame,  in much the same fashion  as the wheel is mounted on a wheelbarrow; when it  was pushed  along the ground by hand  it automatically dropped a  pebble into a container  at each revolution, giving  a measure of the distance travelled. It  was, in effect, the  first odometer.
• Arab traders  brought the magnetic  compass  to the  west in the 12th century AD.
•  Plane tables  were in  use in  Europe in the 16th  century. Surveyors practised the principle  of  graphic triangulation  and  intersection.  In 1615  Willebrord  Snell,  a Dutch mathematician, measured an  arc of  meridian by  instrumental  triangulation.  
• In 1620 the English mathematician Edmund  Gunter  developed a surveying chain, which was  superseded only by the steel tape in the beginning of the 20th century. 
• By the late 18th century modern surveying can be said to have begun. One of the most  notable  early feats  of  surveyors  was the measurement in  the 1790s of the meridian from  Barcelona,  Spain, to  Dunkirk,  France, by two  French engineers, Jean Delambre and Pierre  Méchain. This was to establish the basic  unit for the metric  system  of measurement.  
• Many improvements and  refinements  have been incorporated in all the  basic surveying instruments. These  have  resulted in increased accuracy and  speed  of operations  and have opened up possibilities  for improved methods in  the field. 
• During the  nineteenth  century, the combination of a hot air balloon  and a  camera were used to produce maps and plans. It was difficult to survey large areas because the  balloons  were slow  moving and a  new  photographic  negative had  to be loaded into the camera after each  photograph  was taken. In 1862 union soldiers used  cameras mounted in hot air balloons to  map behind the  confederate lines. 
• It was not until the turn of the twentieth  century, with the developments of the aircraft and invention of the roll of photographic film, that aerial photographs started to be  used  extensively within the survey industry. 
• The first light  wave Electronic  Distance  Measurement instrument  was developed in 1943 to measure the velocity of light. Once the velocity of  light was known, it was then possible to reverse the process  so that a distance could  be measured. 
• In 1954, the light wave was replaced  by a radio wave to increase the distance that could be  measured. In the late 1960s, lasers were first used with EDMs. 
• In the mid to late 1970s, the United States of America sent their first Global Positioning System satellites into space.  The final  development  was the extensive use of computers to perform most common data  processing and recording  of survey data. 

Procedure of surveying

The following  sequence  of steps is  commonly followed  when  carrying  out  a survey: 

(i) Reconnaissance.  

During the  reconnaissance  phase, the  surveyor will  obtain an overall picture of the area that the project will be conducted in. They will  select  where the control points will be located, the accuracy required for the control, and  which survey instruments  will be required for the project. 

(ii)  Measurement  and Marking . 

During the measurement  and marking  phase, the  surveyor  will perform  all the observations  in the field required to accurately determine the control points, as  well as  placing and observing to any  temporary  points  such  as  wooden pegs. They  would also  perform  any  calculations  from the  observations,  such as angular  and linear misclose and area  and volume  calculations. 

(iii)   Plan  Preparation. 

 During the  plan preparation phase, the  calculations that were performed from the field observations would be further enhanced and used to produce the final plans for the project.

Responsibilities of a Surveyor. 

 The responsibilities of the  surveyor  are  many and varied, but can generally be reduced to the following:
1.  Responsibility to the Task.
The  surveyor is  responsible for completing the task required in the most efficient manner and in the  time available. All effort must be made  to ensure that the information supplied by the surveyor  is as  accurate  as  is  possible to  complete the task.  Not all tasks require the same order of  accuracy. By an understanding  of the task the surveyor  must decide on  the accuracy to  be achieved.
2.  Responsibility to the Client or Employer
 The surveyor has a responsibility to the  client or employer to produce what the client requires, within the budget restraints. This may need   patience and tact in  explaining to  the  client the  limitations to  a task.
3.  Responsibility to the Community.
The  surveyor has  a responsibility to the community  in general, to ensure that work undertaken by his team does not damage property or interfere with members of the community. Permission must  be sought  before  accessing private property  or before removing  trees or  shrubbery  to enable survey measurements.
4.  Responsibility to the team .
The surveyor, as the leader of the survey team, has a responsibility to the members of that team  and  must ensure  that their needs are met  regarding their leave, pay, OH&S etc. The surveyor has a  responsibility to  ensure that  all members of the team receive the training needed, not only to complete the  task  at hand,  but also to enable them to advance within their chosen professions.

Role of a Surveyor 

The  role  of the surveyor  is  that of the  leader of the team. With  that  role  come  the responsibilities  outlined above.
 The  role  of the surveyor  is  to perform  the measurements  necessary to  complete any task  required.

Tasks of a Surveyor 

The tasks performed by a  surveyor  will depend on which branch of  surveying they practise  in. The most common tasks involve the determination of height and distances.
1. For the Cadastral Surveyor, the main tasks involve the determination of property boundaries.
2. For the Topographical Surveyor, the main  tasks involve the location of  detail  on the earth’s  surface for the production of maps.
3. For the Engineer Surveyor, the main tasks include  the setting  out of buildings, sewers, drains, bridges and roadways;  determining areas and volumes of  regular and irregular  figures; the preparation  of detailed drawings and plans.
4.  For the Mine  Surveyor, the main  tasks include the setting out of mine  lease boundaries and the calculation of end-of-month volumes.

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IMPACTS OF GLOBAL WARMING ON IRRIGATION AND DRAINAGE DEVELOPMENT

Irrigated agriculture is expected to play a major role in reaching the broader development objectives of achieving food security and improvements in the quality of life, while conserving the environment, in both the developed and developing countries.  Especially as we are faced with the prospect of global population growth from almost 6 billion today to at least 8 billion by 2025. In this context, the prospects of increasing the gross cultivated area, in both the developed and developing countries, are limited by the dwindling number of economically attractive sites for new large scale irrigation and drainage projects. Therefore,any increase in agricultural production will necessarily largely on a more accurate estimation of crop water requirements on the one hand, and on major improvements in the operation, management and performance of existing irrigation and drainage systems, on land other. The failing of present systems and the inability to sustainably exploit surface and ground water resources can be attributed essentially to poor planning , design , system management and development. Concerning agricultural development, most of the world's 270million ha. of irrigated land.Added to this, the systems have to with stand the pressures of changing needs,demands and social and economic evolution. Consequently,the infrastructure in most irrigated and drained areas needs to be renewed or even replaced and thus redesigned and rebuilt, in order to achieve improved sustainable production. This process depends on a number of common and well-coordinated factors,such as new and advanced technology,environmental protection, institutional strengthening, economic and financial assessment, research thrust and human resource development. Most of these factors are well-known and linked to uncertainties associated with climate change, world market prices and international trade. These uncertainties call for continued attention and suitable action on many  fronts,  if productivity and flexibility in agricultural systems are to solution.

PROBLEMS AND SOLUTIONS :

All the above factors and constraints compel decision makers to review the strengths and weaknesses of current trends in irrigation and drainage and rethink technology, institutional and financial patterns, research thrust and manpower policy so that service levels and system efficiency can be improved in a sustainable manner. To develop this process in a well-planned and controlled way the following aspects need to be adequately addressed: 

•  Technology;
•  Institutional and financial aspects; 
•  Research thrust; 

Human resources and networking.

Technology in irrigation and drainage development is concerned with the planning, design and control of the systems, including water conveyance, regulation  structures, water quality and environmental protection measures. It is also current climate forcing is unprecedented and can be attributed to greenhouse gas emissions, deforestation, urbanization, and changing land use and agricultural practices . The increase in greenhouse gas emissions into the atmosphere is responsible for the increased air temperature, and this, in turn, induces changes in the different components making up the hydrological cycle such as evapotranspiration rate, intensity and frequency of precipitation, river flows, soil moisture and groundwater recharge. Mankind will certainly respond to these changing conditions by taking adaptive measures such as changing patterns in land use. However, it is difficult to predict what adaptive measures will be chosen, and their socio-economic consequences. Concerning global patterns the following considerations can be drawn from analysis of the hydrologic and meteorological time series available: 

•  Average global temperature rose by 0.6 ˚C during the 20th century 
•  1990’s was the warmest decade and 1998 the warmest year since 1861
• The extent of snow cover has decreased by 10% since the late 1960
• Average global sea level rose between 0.1 - 0.2 metres during the 20th century
•  Precipitation increased by 0.5 to 1% per decade in the 20th century over the mid and high latitudes of the northern hemisphere and by between 0.2 and 0.3% per decade over the tropics (10˚ N to 10˚ S)
• Precipitation decreased over much of the northern sub-tropical (10˚ N to 30˚ N) land areas during the 20th century by about 0.3% per decade
• The frequency of heavy rain events increased by 2 to 4% in the mid and high latitudes of the northern hemisphere in the second half of the 20th century. This could be the result of changes in atmospheric moisture, thunderstorm activity, large-scale storm activity, etc.
• Over the 20th century land areas experiencing severe drought and wetness have increased
• Some regions of Africa and Asia recorded an increase in the frequency and intensity of drought in the last decade
• CO2 concentration has increased by 31% since 1750
• 75% of CO2 emissions is produced by fossil fuel burning, the remaining 25% by land use change especially deforestation
• Methane CH4 has increased by 151% since 1750 and continues to increase. Fossil fuel burning, livestock, rice cultivation and landfills are responsible for emissions [15]; 
• Nitrous Oxide (N2O) has increased by 17% since 1750 and continues to increase. This gas is produced by agriculture, soil, cattle feed lots and the chemical industry. 

The Stratospheric Ozone (O3) layer has been depleting since 1979 [16]. Current scientific research is focused on the enhanced greenhouse effect as the most likely cause of climate change in the short-term. Until recently, forecasts of anthropogenic climate change have been unreliable, so that scenarios of future climatic conditions have been developed to provide quantitative assessments of the hydrologic consequences in some regions and/or river basins. Scenarios are “internally-consistent pictures of a plausible future climate.

 These scenarios can be classified into three:

•  Hypothetical scenarios;
•  Climate scenarios based on General Circulation Models. 
• Scenarios based on reconstruction of warm periods in remarks

CLIMATE CHANGE AND IRRIGATION REQUIREMENTS

 Agriculture is a human activity that is intimately associated with climate. It is well known that the broad patterns of agricultural growth over long time scales can be explained by a combination of climatic, ecological and economic factors. Modern agriculture has progressed by weakening the downside risk of these factors through irrigation, the use of pesticides and fertilizers, the substitution of human labour with energy intensive devices, and the manipulation of genetic resources. A major concern in the understanding of the impacts of climate change is the extent to which world agriculture will be affected. Thus, in the long-term, climate change is an additional problem that agriculture has to face in meeting global and national food requirements. This recognition has prompted recent advances in the coupling of global vegetation and climate models. In the last decade, global vegetation models have been developed that include parameterizations of physiological processes such as photosynthesis, respiration, transpiration and soil water intake . These tools have been coupled with GCMs and applied to both paleoclimatic and future scenarios. The use of physiological parameterizations allows these models to include the direct effects of changing CO2 levels on primary productivity and competition, along with the crop water requirements. In the next step the estimated crop water demands could serve as input to agro-economic models which compute the irrigation water requirements (IR), defined as the amount of water that must be applied to the crop by irrigation in order to achieve optimal crop growth.  Estimates of long-term average climate change have been taken from two different GCMs:  

1.  The Max Planck Institute for Meteorology (MPI-ECHAM4), Germany;

 2.  The Hadley Centre for Climate Prediction and Research (HCCPR-CM3), United Kingdom. 

  

PLANNING AND DESIGN OF IRRIGATION AND DRAINAGE SYSTEMS UNDER CLIMATE CHANGE 

Uncertainties as to how the climate will change and how irrigation and drainage systems will have to adapt to these changes, are challenges that planners and designers will have to cope with. In view of these uncertainties, planners and designers need guidance as to when the prospect of climate change should be embodied and factored into the planning and design process . An initial question is whether, based on GCM results or other analyses, there is reason to expect that a region’s climate is likely to change significantly during the life of a system. If significant climate change is STRATEGIC ACTION PROGRAM The above described themes and principles tackle the root cause of the major problems encountered in irrigation and drainage system development. To be effective, they have to be translated into actions through the formulation of programs that take into account the actual conditions of the environment where they are expected to be implemented. These programs would have to include:  adoption of a comprehensive approach that considers land and water use and management and the environment in an integrated manner;  promotion of regional co-operation to ensure that the concerns of all parties are translated into sound decisions;  recognition of the relationships between different land uses and availability of water resources (quantity and quality);  encouragement of broad based participation, including governments, professional and research institutions and non-governmental organizations;  endorsement of phased programs of action at the international (river basin), national, regional and local levels.

 CONCLUDING REMARKS  

1. Despite the enormous advances in our ability to understand, interpret and ultimately manage the natural world we have reached the 21st century in awesome ignorance of what is likely to unfold in terms of both the natural changes and the human activities that affect the environment and the responses of the Earth to those stimuli. One certain fact is that the planet will be subjected to pressures hitherto unprecedented in its recent evolutionary history.
2.  Most of the world’s irrigation and  drainage  facilities were developed on a step-by-step basis over the centuries and were designed for a long life (50 years or more), on the assumption that climatic conditions would not change in the future. This will not be so in the years to come, due to global warming and the greenhouse effect. Therefore, engineers and decision-makers need to systematically  review planning principles, design criteria, operating rules, contingency plans and water management policies. 
3. An integrated approach to food production and irrigation and drainage systems development is needed , so as to maximize water application , reduce deep percolation and intercept , isolate and recycle low-quality water effluents . 
4. Possible impacts of climate variability that may affect planning principles and design criteria include changes in temperature, precipitation and runoff patterns, sea level rise, flooding of coastal irrigated and rainfed lands. 
5. Uncertainties as to how the climate will change and how irrigation and  drainage systems  will have to adapt to these changes are issues that water authorities are compelled to cope with. The challenge is to identify short-term strategies to face long-term uncertainties. The question is not what is the best course for a project over the next fifty years or more, but rather, what is the best direction for the next few years, knowing that a prudent hedging strategy will allow time to learn and change course.
6. The planning and design process needs to be sufficiently flexible to incorporate consideration of and responses to many possible climate impacts. The main factors that will influence the worth of incorporating climate change into the process are the level of planning, the reliability of the forecasting models, the hydrological conditions and the time horizon of the plan or the life of the project.
7. The development of a comprehensive approach that integrates all these factors into irrigation and drainage  project selection, requires further research of the processes governing climate changes, the impacts of increased atmospheric carbon dioxide on vegetation and runoff, the effect of climate variables on water demand for irrigation and the impacts of climate on infrastructure performance.
8. Resource http://www.ipcc-data.org/observ/clim/cru_climatologies.html

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Top software for civil engineering

1. Drafting softwares

 AutoCAD from Autodesk. 

   Drafting needs AutoCAD, alla over the     world. It is being used in wide range of   indursties for drafting of building   designs elevations. Here is a quick tip   for you .If you are a student you can use   the latest version of AutoCAD for free with education license. 

2. Design and Analysis

In design and analysis of beams column of the buildings.
Here is the some software which are recommended by many civil engineering professional for students.

1. STAADpro.

Autodesk revit is a building information modelling software for architects, landscape architects, structural engineers, mechanical, electrical, and plumbing 

2. Tekla structure.. 

Tekla structure is a building information modelling software that in corporate different kind of buildings and also used for planning of a project . 

PLANNING &MANAGEMENT

For construction management and planning software like

1. MS office
2. MS project. 

1. Primavera

Primavera is an enterprise project portfolio management software.. It includes project management, scheduling, risk analysis, opportunity management, 

MODELLING & ARCHITECTURE 3D-ANIMATION & RENDERING

1. 3D-Max

2. Sketch up

TRANSPORRATION

MX Road

Vissim 

GEOTECHNICAL ENGINEERING

1Geoslope

2. Plaxis

3. GEO5...

BUILDING INFORMARION MODELLING

Collabration between different function related to architecture engineering and construction industry is achieved by combining all these data with the help of building information modelling and thus carrying out planning, design construction operation and maintance.

1. Revit by Autodesk.

2. Tekla. 

SURVEYING & INFRASTRUCTURE DESIGN

1 Autodesk civil3D

2 ArcGIS

The system provides an infrastructure for making maps and geographic information available throughout an organization, across a community, and openly on the Web.

MATHEMATICAL CALCULATION & ANALYSIS

 For mathematical programming language like

1Math work.

2 Python

3 Mathcad.  

The mathcad interface allows users to combine a variety of different elements mathematics, descriptive text, and supporting imagery into the form of a worksheet, which is naturally readable. Because the mathematics are core to the program, the math is inherently live, dynamically recalculating as upstream values are altered. This allows for simple manipulation of input variables, assumptions, and expressions, which in turn update in real-time. 

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Futuristic Material for Buildings | TRANSLUCENT CONCRETE

Translucent concrete

• Translucent lightweight Concrete is anew material with various applications in the construction field,architecture, decoration and even in furniture industry. Intoday’s time where whole of the research isconcentrated towards non utilization of natural resources as much aspossible and toreduce its consumptionwhich are decreasing with time,Lightweight LiTraCon (Lightweight light transmitting concrete) is alightweight translucent concrete building material made of fine concrete embedded withup to5% by weightofconcrete mixwhich areimpregnated inside the concrete cubes so that light can be transmitted from theoutside in or inside out of the building. Due to great economic growth, urbanization, population growth, spaceutilization worldwide, there is drastic change in concrete technology. Most of the big buildings are built closeto each other all in the same areas like sky scrapers There arises one of biggest problem in deriving naturallight in building due obstruction of nearby structures. When buildings are stacks closed to eachother, there isnot much natural sunlight passing through it.A wall made of "Light LitraCon" has the strength of traditional concrete and an embedded array of glassrodsthat can display a view of the outside world. Thousands of optical glassrodsform amatrix and run parallel toeach other between the two main surfaces of every blocks where in which Shadows on the lighter side willappear with sharp outlines on the darker one. An opticalglassfibre is a flexible transparent fibre made ofglass (silica)or plastic, slightly thicker than a human hair & is a three layered cable made up of Buffercoating, cladding and core with transmits light through the core ofglass rods.

Materials

1. Ordinary  Portland  Cement  of  53 Grade. Manufactured Sand of  pertaining  Sieve  size  (<4.75mm)  as  per  IS  standards. 

2. Glass  Rods  0.5 mm  in Diameter are  used     for  casting  concrete.

Methodology

Preliminary tests were conducted on the normal conventional concrete materials as per IS standards &specifications for its physical & engineering  properties, cubes were casted in the standard metallic moulds &vibrated to obtain the required sample size of specimen. The moulds were cleaned initially and oiled on all thesides before concrete sample is poured in to it. Thoroughly mixed concrete is poured into the moulds in threeequal layers and compacted using vibrating table for a small period of 5 minutes. The excess concrete isremoved out of the mould using trowel and the top surface is finished with smooth surface.The manufacturing process of transparent concrete is same as of the regular conventional concrete blocks withthe Only change isglass rodsare spread throughout the fine aggregate and cement mix & Small layers of theconcrete are poured on top of each other and infused with therodsin the wooden casted box. Lighttransmitting concrete is produced by adding 1%, 2%, 3%, 4% & 5% ofglass rodsbyweightinto the concretemixture, thetranslucent concrete mixture is made from fine aggregate materials only & does not containcoarse aggregates.Glass rodsand concrete are alternately inserted into moulds at an intervals of approximately1.5cmspacing&thecasted materials are cut into small panels or blocks of the specified thickness finally the surface istypically polished resulting in semi-gloss to high-gloss surface finish.After 24 hours the samples of both normal conventional concrete & translucent concrete were demoulded andput in curing tank for the respective periods of 7, 14, 21 and 28 days & a set of 5 samples were prepared foreach stage of curing. The temperature of curing tank was maintained about 25 degree during the analysis ofcharacteristic strength & the results were tabulated.
The main aim of the methodology is to-
 To calculate the compressive strength of  M25 grade plain concrete & translucent concrete by laboratory experiments as per IS specifications.

•  To calculate the Split tensile strength of  M25 grade plain concrete & translucent concrete by laboratoryexperiments as per IS specifications.
•  To calculate the Flexural strength of  M25 grade plain concrete & translucent concrete by laboratoryexperiments as per IS specifications
• Tests(physical properties) conducted on Concrete materials
• Test on cementFineness of cement.
• Normal Consistency of cement.
• Soundness test.Specific gravity.
• Initial setting time of cement.
• Final setting time of cement.

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Top 5 career option after civil engineering

1 Job &Internship

•  Mininum requirement B. Tech/B. E. 
•  You can start a job as a fresher in construction real estate and infrastructure and project industry as   a site engineer

• If you are finding it difficult to get a job it is always advisable to get into an internship in any company to your core domain. 

• Companies like L&T(Larsen&Turbo) pay4-5lacs per annum to fresher's but getting job in L&T is not an easy task. They hire on the basis on valid gate score.

2. Management studies in India

• Minimum requirement B. Tech/B. E.&CAT 

• MBA in construction management, real estate management, project management, infrastructure management

• You should attempt for CAT and try to get into IIMS. 

3 MS from outside India

• Minimum requirement B. Tech/B. E&GRE 
• Ms in civil engineering in U. S, Canada, U. K, South East Asia&Australia is considered the best among professionals . 
• Depending upon your GRE score you can choose one of the too ranking universities for MS in civil engineering 

4 Higher education in India

• Minimum requirement B. Tech/B. E &GATE.
• You should choose a specialization for M. E. /M. TECH from IITS, IISC, NITS, with a valid gate score. If your gate rank in between 200 to 300  u should select for iits and nits . So you need to do more and more hardwork. 

5. PSUs &IES

• If you want to serve under central government and different ministries.Then you should prepare yourself for UPSC  based exam Engineering Services Examination in which you work for the following wings like IRSE, CPWD, IDSE, BRO, NHAI etc.And other sate public services commission. 

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List of top 10 famous civil engineers in the world

• Most individuals would find it difficult to think of a life where civil engineers do not exist. Whether it is building roads, buildings, sewage systems, dams, bridges or airports, one would have to think of a civil engineer almost immediately. However, not all civil engineers end up working in these large, well-paying capacities. Some engineers may even just work in the smaller aspects of civil engineering like designing or looking into the research process or might even specialize in departments like structural construction, environment or even transportation. As the population grows around the world, the need for more civil engineers arises. According to recent studies, it is estimated that in the near future, there will be a sudden escalation in civil engineering jobs around the world. While designing, constructing and operating mammoth infrastructure is a part of their job description, civil engineers are also required to boost the conditions of old and existing structures, while conforming to social and environmental policies and norms. Around the world, in order to become a civil engineer and in order to be able to practice in a particular department, a person would need to have a good higher-secondary degree and a degree in mathematics, engineering or the sciences. Here is a compilation of a list of famous mind body therapists, learn more fascinating facts and details about them with their biographies that include trivia, interesting facts, timeline and life 

1 Isamdard Kingdoms Burnel.     British

2 Gustave Eiffel .    French

3 M. Visvesvaraya.    Indian

4 George Stepheson.   British

5 John Monash.   Australian

6 Ren Zhengfei.  Chinese

7 Leslie Groves.  American

8 Fazlur Rahman Khan.       Bangledeshi-American

9 Thomas Telforf.  Scottish

10 Abu Hamza-Al-Masri.  Egyptian

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