Sources of Irrigation water

Considerations for using surface water as a source:

1.     Lowest available water

2.     Crop water requirement

-          Water needed (S1)= R1-x1

-         R1= Crop water requirement

-         x1= Effective rainfall

3.     Water quality ( salinity & toxicity)

4.     Water right – Other users

-         Domestic water supply

-         Navigation

-         Fish culture

-         Industry

-         River morphology

5.     control structure

-         initial cost

-         operating & maintenance cost





Consideration for Ground water as a source:

1.     Crop water requirement

2.     Availability of surface water source

3.     Position of ground water table

4.     Water quality

5.     Ground water recharge.

6.     Environmental impact



Conjunctive use of Surface water & Ground water:

-         Use of both SW & GW

-         Factors governing the percentage of sharing SW & GW

i)       Natural recharge

ii)    Artificial recharge

iii)  Aquifer characteristics

iv)  Availability of surface water

v)    Availability of fuel

vi)  Operation & Maintenance cost for pumps

vii)           Economic consideration

Concept of multipurpose irrigation project

- A multipurpose project is one which serves more than one purpose
- Such as irrigation project can serve the following purposes.

§ Storage, control & utilization of water for irrigation.
§ Development of hydro-electric power.
§ Flood control
§ Silt control in rivers & canals
§ Inland navigation
§ Water supply
§ Fish culture
§ Recreation

- A multipurpose project entails the study of different sciences. Such as-
o Engineers
o Agriculturist
o Soil Scientists
o Hydrologist
o Meteorologist
o Administrators
o Planners
o Farmers. - Beneficiary
o Economist
o Sociologist

Considerations for development of any water resources project

1. Economic consideration:
- Cost-benefit ratio
- Cost Involves: Investigation, planning, design, construction, operation, maintenance.
- Benefits: which can be converted to money.

2. Social & economic consideration of beneficiary:
- Land ownership pattern
- Local availability of labour
- Existing farming practices facilities
- Crop type & calendar
- Transportation, storage & marketing facilities
- Banking facilities
- Technical advisory services
- Overall education level/consciousness
- Peoples participation.

3. Environmental consideration:
- EIA: Environmental Impact Assessment.
- Submergence of land & forestry
- Atmospheric pollution for organic decomposition
- Water logging
- Water borne diseases.
- Fish habitats.

Type of Irrigation Project
(A) W.r.t procurement process of water
1. Storage type
2. Diversion type
3. Combination of storage & diversion
4. River pumping.
5. Ground water pumping
6. Reclamation of wastes & sewage water

(B) W.r.t area coverage:
1. Major irrigation project: > 10,000 ha,
2. Medium irrigation project (2,000-10,000) ha
3. Minor irrigation project < 2,000 ha

(c) W.r.t purpose of the project:
1. Single purpose
2. Multipurpose.

Irrigation practice in Bangladesh:
Water management in Bangladesh involves a wide range of interventions in the country’s land and water regime but two main categories can be distinguished;
- Irrigation
- Flood control and drainage

National water policy:

Main objective is to promote agricultural growth through private development of groundwater and where feasible, with surface water development.

There are six main elements in the Government policy.
1. Encourage and promote continued development of minor irrigation without affecting drinking water supplies.
2. Encourage future ground water development for irrigation by both public and private sectors.
3. Improve resources utilization through conjunctive use of all forms of surface water and ground water for irrigation.
4. Strengthen crop diversification programs for efficient water utilization.
5. Address the problem of agricultural chemicals polluting surface water and ground water.
6. Strengthen systems of monitoring water use, water quality and ground water recharge.

Categories:
Two Categories of irrigation: minor and major irrigation
- minor irrigation is mostly by farmer-operated and owned tube-wells and low lift pumps. and 92% of the total.
- major irrigation is mostly by BWDB surface irrigation project.
- Minor irrigation is mainly done by STW.
- STW irrigation is most developed in NW, NC and SW regions.
- Surface water irrigation is mainly in NE, SE and SC regions where there is a higher density of small perennial channels and other water bodies.

Land resources:
Bangladesh has a total area of 14.7 Mha and a net cultivable land of 8.3 Mha. But at the end of 2025 this will reduce to about 7.7 Mha.

Cropping patterns:
Ø Kharif I (March to July): Pre-monsoon season. Aush is planted. Jut is also.
Ø Kharif II (July to December): The monsoon. Aman is planted.
Ø Rabi (November to April): The winter season. Boro is main crop. And others are wheat, pulses, oilseeds, vegetables etc.

Irrigation Engineering:

- Is an applied subject dealing with investigation, planning, design, execution, control & servicing of irrigation and related works.
- Is an inter disciplinary area

Concept of multipurpose project:
-         A multipurpose project is one which serves more than one purpose
-         Such as irrigation project can serve the following purposes.

§  Storage, control & utilization of water for irrigation.
§  Development of hydro-electric power.
§  Flood control
§  Silt control in rivers & canals
§  Inland navigation
§  Water supply
§  Fish culture
§  Recreation

-    A multipurpose project entails the study of different sciences. Such as-

o   Engineers
o   Agriculturist
o   Soil Scientists
o   Hydrologist
o   Meteorologist
o   Administrators
o   Planners
o   Farmers. - Beneficiary
o   Economist
o   Sociologist

Considerations for development of any water resources project

1. Economic consideration:
- Cost-benefit ratio
- Cost Involves: Investigation, planning, design, construction, operation, maintenance.
- Benefits: which can be converted to money.

2. Social & economic consideration of beneficiary:
-  Land ownership pattern
- Local availability of labour
- Existing farming practices facilities
-  Crop type & calendar
- Transportation, storage & marketing facilities
- Banking facilities
- Technical advisory services
- Overall education level/consciousness
-  Peoples participation.

3. Environmental consideration:

-         EIA: Environmental Impact Assessment.
-         Submergence of land & forestry
-   Atmospheric pollution for organic decomposition
-   Water logging
-   Water borne diseases.
-   Fish habitats.

Type of Irrigation Project
(A) W.r.t procurement process of water

1. Storage type
2. Diversion type
3. Combination of storage & diversion
4. River pumping.
5. Ground water pumping
6. Reclamation of wastes & sewage water

(B) W.r.t area coverage:
1. Major irrigation project: > 10,000 ha,
2. Medium irrigation project (2,000-10,000) ha
3. Minor irrigation project < 2,000 ha



(c) W.r.t purpose of the project:
1.     Single purpose
2.     Multipurpose.                          

Irrigation practice in Bangladesh:

Water management in Bangladesh involves a wide range of interventions in the country’s land and water regime but two main categories can be distinguished;

-         Irrigation

-         Flood control and drainage



National water policy:

Main objective is to promote agricultural growth through private development of groundwater and where feasible, with surface water development.

          There are six main elements in the Government policy.
1.           Encourage and promote continued development of minor irrigation without affecting drinking water supplies.
2.           Encourage future ground water development for irrigation by both public and private sectors.
3.           Improve resources utilization through conjunctive use of all forms of surface water and ground water for irrigation.
4.           Strengthen crop diversification programs for efficient water utilization.
5.           Address the problem of agricultural chemicals polluting surface water and ground water.
6.           Strengthen systems of monitoring water use, water quality and ground water recharge.



Categories:

Two Categories of irrigation: minor and major irrigation

-         minor irrigation is mostly by farmer-operated  and owned tube-wells and low lift pumps. and 92% of the total.

-         major irrigation is mostly by BWDB surface irrigation project.

-         Minor irrigation is mainly done by STW.

Irrigation as a subset of production systems and the environment

One can not simply start irrigation without also improving other production inputs (which may also be limiting crop production)

Inputs:
- Fertilizers
- Labor availability
- Markets of produce
- Pest control
- Cultivation equipment
- Drainage

Yield-water application interaction:



           Fig: General crop water production function


Shape = f (depends on soil, climate, crop type, fertility, precipitation etc.).

Law of conversion of mass:
- Water can not be destroyed or created.
- It must be accounted for with in an irrigation system or river basin.
- The only “Consumptive” or consumed portion of diverted water is evapotranspiration, or Et.

Water rights: In addition to determining the adequacy of a water sources one must also consider the effect of a diversion or change in water use on other users. Many of these users may hold a “Water right.”
A water right is a legal deed detailing the ownership of the right to divert and beneficially and consumptively use of water.

A water right usually has 3 parts:
1. Length of the time
2. Maximum rate of diversion
3. Maximum land area which can be irrigated

Unfortunately there is no overall water law, formal system of water rights or regulatory instruments for water use and allocation in Bangladesh.

Followings are available:
1. The irrigation Act (1876)
2. Bangladesh water and power development boards ordinance (1972)
3. Local government ordinance (1983)
4. Irrigation water rate ordinance (1983)

Main thing is that in practical no law is maintained and there is no monitoring.

Importance of Irrigation

Definition of Irrigation: Irrigation is the artificial means of supplying water to plants for its growth and maturity

Necessity of Irrigation:
1. Rainfall < water requirement for plants
2. Rainfall is sufficient but the spatial distribution is not as per requirement
3. Rainfall is sufficient, the spatial distribution is also good but the temporal distribution is not as per requirement
4. Advanced scientific development, such as use of fertilizer, insecticide etc.

Objectives of Irrigation:
1. Ensure enough moisture essential for plant growth
2. Provide crop insurance against short duration of drought
3. Cool the soil and atmosphere to provide a suitable surrounding
4. Wash out / dilute harmful salts, chemical in the soil
5. Reduce hazards of soil piping
6. Soften the tillage pan

Advantage of Irrigation:
1. Increase of food production
 Multiple cropping
 Growing high yielding varieties
 Timely agricultural operation
 Control of weed

2. Modify soil or climate environment – leaching
3. Elimination of mix cropping
4. Lessen risk of catastrophic damage caused by drought
5. Increase income/national cash flow
6. Increase labor employment
7. Increase standard of living
8. Increase value of land
9. Domestic and industrial water supply
10. Improve communication and navigation facilities
11. Improvement in the ground water storage
12. Development of recreation facilities
13. Improve fish culture
14. Generation of hydro-electric power

Disadvantage of Irrigation:
1. Water logging
2. Ill aeration of soil
3. Pollution of under ground water
4. Result in colder and damp climate causing diseases like malaria


Social and environment aspects of irrigation

 Agriculture is the largest sector of the Bangladesh economy
 The largest source of employment
 Of 17 million rural households, 11 million are engaged in farming
 Two types: small holding farmers and medium-holding farmers
 Constraints to productivity and expansion of irrigation among small holders include lack of access to cheap credit, low incentive to invest in inputs and irrigation, insecurity of crops, lack of knowledge etc.
 Require good attention to low interest credit and information packages.
 Main environmental issue is the effects on ponds and stream flows in dry season.
 Use of fertilizer deteriorates water quality
 Some research shows that arsenic problem may also related with the ground water irrigation
 Irrigation structures reduce fish migration of the river system. Some fish friendly structures reduce this problem. Example: Pilot Fish-pass project connecting the Manu River and Kawadighi Haor in North East Region.

ENVIRONMENTAL SCIENCE

INTRODUCTION
Environmental Science is related to the sector of geo-hydrology hydrology,  and meteorology insofar as idea of groundwater flows is needed to realise pollutant transport. Engineers related to environment  are also connected with reduction and elimination of pollution,  industrial ecology and green engineering.

Environmental Science also introduce with the collection of huge data on the environmental consequences of proposed actions and the effect of assessment of proposed actions for the purpose of policy maker and assisting society   in the making process for decision.  The component of Environmental Science under Civil Engineering deals with the treatment of chemical, biological, and/or thermal waste, the purification of water and air, and the remediation of contaminated sites, due to prior waste disposal or accidental contamination. Aim of this course is to provide the students a basic understanding of Environmental Science for the sustainable development of the society.

ENVIRONMENTAL ENGINEERING  LEARNING OBJECTIVES
1. Clearly understanding the relation between man and environment and the complications of environment.
2. Gathering knowledge about biosphere, ecosystem and biodiversity.
3. Studying the effect of different parameters like agriculture, urbanization, and solid waste management etc. of lithosphere.
4. Studying the issues related with atmosphere such as air pollution, global warming, ozone layer depletion etc.
5. To provide basic understanding of hydrosphere related topics like water pollution and prevention, wetland management, problems related with health and toxicology.

LEARNING OUTCOMES
1. The effect of human and their activities on environment would be understood.
2. Students would gather information on the environmental consequences of proposed actions and the assessment of effects of proposed actions.
3. The student would be benefited by knowing the treatment of chemical, biological, and/or thermal waste, the purification of water and air, and the remediation of contaminated sites, due to prior waste disposal or accidental contamination.
4. Another outcome of this course is to provide the students a basic understanding of Environmental Science for the sustainable development of the society.

Friend this is a introductory post. I am going to give you the proper instruction about bellow article:  

Topics for discussion

Introduction to environment and  man. Major environmental components.

Brief history of earth, bio-geo-chemical cycles, environment  and the population ; basic population dynamics.

Biosphere: ecosystem and ecological concept, Flow of energy and matter  through an ecosystem.

Biodiversity; Lithosphere: environment and agriculture ; urbanization; waste management of hazardous and solid.

Solid and hazardous waste management; Atmosphere: chemistry of air; urban air pollution.

Global warming; acid rain;  ozone layer depletion; Hydrosphere: water chemistry.

Pollution of water and prevention

Water pollution and prevention; and coastal management and wetland

Alternative energy sources.

Environmental health and toxicology.

Sustainable development.

Concluding