The availability of water for humans has always been vital, because besides the support it received in the cultivation of land, creating wealth and getting her power. The management of water has resulted in human history disputes and confrontations. The man became sedentary about 3,000 years before Christ, to dominate the conduct of water, building dams in rivers carrying water where there was good land. With the mastery of this technique, begins on irrigated agriculture. While we are the first villages with adobe houses, as the populations in the region between the Tigris and Euphrates in ancient Mesopotamia. Possibly the domain of irrigation technique prompted a new way of life, safer and less risky than the wandering life of a hunter. From now could have food without having to move from one place to another. It was not necessary to seek sustenance continued transfers. With agriculture comes a new revolution to man control over water, the art of irrigation, getting food without having to make large migrations. For those people who were on the move, was a real change in their habits.

Besides the man who got support for your group or family, he realized he could store food crops and make sure not for a day or two as when a hunter. He now had food for several months or perhaps years. This technique discovered would change the concept of this wandering life, being born the first peoples. That incipient agriculture promoted the exchange of plant products, meat hunted by nomads, born of barter trade. These changes are so important in history were made possible, ultimately, by water, by its domain and use. Why I said that this precious liquid is and will be held up by disputes over its possession at all times in history, both past and future. Where there's water and land is wealth.

Objectives

Establishing an organization and necessary and proper distribution of water between the units, and obtain the high yields of irrigated crops. Establish rules correctly biased and the irrigation regime, ie, number of irrigation, irrigation period and irrigation rules.

Water Balance:  The water balance is established for a given place and period, by comparison between inputs and losses of water there and for that period. It also takes into account the provisioning and subsequent withdrawals on those reservations. Contributions are made of water from rainfall. The losses are due primarily to the combination of evaporation and plant transpiration, which is designated under the term evaporation transpiration. The two quantities are evaluated in water per unit area, but generally result in water heights, the most commonly used unit is the millimeter. As these two quantities physically homogeneous, they may be compared by calculating either their difference (rainfall less evaporation), or their relationship (rainfall over evaporation). The balance is clearly positive when the difference is positive or when the ratio is greater than one. We choose one or another expression in terms of amenities or various obstacles. The runoff from a unit area is counted in losses. The infiltration is considered a place in reserve in the form of groundwater or pore water in the soil. The study of water balance is complicated by the fact that the two variables considered are not independent. The evaporated amount obviously depends on the amount of water available: ceases when the volume of water supplied by rainfall is exhausted. This led to introduce the concept of potential evaporation transpiration: the amount of water that can only happen in the atmosphere depending on the state of it, assuming that the amount of water available is not a limiting factor. It is common in the study of water balances, comparing precipitation P and potential evaporation transpiration ETP, which allows to distinguish different situations depending on thresholds that are directly meaningful to a place or a given period: If P PET, actual evaporation is equal to the ETP, there will be runoff and stockpiling, the period is called surplus. The practical problems relating to measurements, the orders of magnitude considered, require changes in methods of study and presentation of water balance. Rainfall is usually measured by a dense network of observation stations old, fairly reliable and comparable. Potential evaporation transpiration measurements are possible, with devices like the evaporation meter of Piche (protected) or the ship Colorado. But the observation network does not include the same characteristics of density, comparability and reliability of rainfall, while often tends to proceed to the calculation of the balance sheets, evaluations of potential evaporation transpiration, which are made taking into account factors such relatively well-known potential evaporation transpiration.

Soil Water Regime

The soil water regime is a pervasive feature of all the phenomena of moisture ingress into the soil, its movement, the change in their physical and spending. Elements of water regime are the infiltration of soil moisture, condensation, evaporation, making moisture by the plant root system, seepage of moisture into the layers that lie deep, capillary absorption , freezing and melting, the portion of moisture by the solid phase, and so on. From a quantitative standpoint, the water regime is represented by the water balance equation and the equation of moisture movement. The soil water regime is one of the key factors in the formation of soils; depend on it many of the properties of the soil, and among the most important fertility. The water regime largely determines air systems, thermal and feeding ground for that to improve with the help of irrigation can be improved to such schemes.

The different proportions of the elements water regimes create different types of water regimes. To cover them, using more general indices of water regime, which are reduced to the comparison of two fundamental factors, which are atmospheric deposition and irrigation, as major components of income and total evaporation, as a major component of expenditure balance. In this case, the total evaporation capacity is matched by more determined evaporation from the surface of EO water and data were obtained at the meteorological stations. G. N. Visotski proposed use to the property of the types of water regimes the coefficient of wetting:

Plan for irrigation of an agricultural unit

The plan ensures irrigation system and irrigation of crops is an integral part of the production plan of each farm unit. The main objective of the annual water use is to take stock of this and work to see if the supply sources may or may not provide the water needed and to determine the need for sprinklers and irrigation equipment.

The water management plans depend on the following factors:

1. Capacity of the power supply.

2. Quantity and number of different crops will be irrigated.

3. Type and condition of the land to irrigate.

4. Technical condition of the irrigation system.

5. Organization of work in irrigation.

To compose an irrigation scheme for a farm unit and materials needed following information:

1. Plan irrigation scheme area in 1:10000 or 1:5000 scale, which contains the boundaries of each parcel, lot, district, or plan, that is, each farm unit must be clearly defined and the source, the channels and distribution boxes for each parcel of irrigation depending on the extension of the irrigation system. Scheme should be brought in hydrometric posts and observation wells for groundwater levels. In case of no plans at scales above, use other or just an outline.

2. Data on type and area occupied, or crops planted and their location in the plots.

3. Quantities of water needed in terms of crops and the standards considered in the plan.

4. Details about the leak in the channels and its coefficient of useful and beneficial use of water, and the gross standards.

5. Characteristics of soils in each field and also depth of wetting, the slope and irrigation technique used in that field.

6. Data on the ability of the channels.

7. Number of sprinklers, pumps and spray equipment and necessary existence.

Irrigation System Plan

It is made after irrigation plans prepared at the farm and make requests for water. Moreover these requests for water are compared with the possibilities of the source.

The plan irrigation system consists of 3 parts:

1. Sum of all consumer plans (plans, districts).

2. Comparison of the volume of water available for the system with water needs.

3. Water distribution plan within the system for each primer of each farm unit.

In this case were defined for the irrigation project area 1, eight batches of 218 ha each, which will be cultivated for bananas and sugar cane

Water Distribution

The correct distribution of particular importance as water absorbs a large irrigation system as a farm unit. When the water needs are beyond the amounts available is necessary to make a water distribution system for priority crops. Economic calculations are done to see what action to take. Sometimes they take the option to make only those that produce less irrigation water losses.

When a large water deficit is usually done in some cases, a system of water distribution d as a percentage of the amounts raised for each consumer, and this expenditure remains at all times in the primers. The distribution of water within the agricultural unit is made according to domestic needs.

For the irrigation project area 1, has the source reservoir Canoes, which has a main channel that derives the water sector, where they take the necessary flow required for the 8 lots for both crops grown by the calculations ( See Tables 1 and 2)

In practice there are various methods of distribution of water in an irrigation system:

1. Distribution with constant spending. Ensures a given expenditure, constant for each consumer (plan, district lot), throughout the irrigation season. The advantages of this method are that each channel runs a constant water flow and its capacity can be minimized and water losses. The consumption of water within the agricultural unit can be arranged to suit the same unit. This method is especially advantageous when driving water through pipes with minimum cross sections.

2. Distribution shifts. BOUT applies particularly in the smaller channels (tertiary and secondary). For each lot and parcel determines the period in which they should receive water (hours or days a week). This method has its advantages and disadvantages. Among the latter are not well meet the needs of water and wastage of this, moreover, did not have and account rainfall, existing temperature and winds.

3. Water distribution applications. Ensure water is always required. Its benefits can include correspondence with the water needs, but requires greater channel capacity.

This method is also demanding in-depth knowledge of the real needs of water by plants.

For the case of the distribution is taken constant expense, and water was taken during the time that is determined by irrigation schemes, bounded by hydrological modulation calculated for the season

Hydrological Modulation

Once the irrigation system calculated for each crop is determined on the day of hydrological modulation which in its first construction variant is often called preliminary or incomplete. When you have cultivated land and land in crop rotation with different watering regimes, hydrological modulation graphics are built for all cultivated land and in rotation.

In the case of the irrigation project were defined 8 lots each with 218 ha in extent, important data for the calculation and delineation of hydrological modulation where lots 1, 2, 4, 6 are cultivated sugarcane and 3.5 with lots banana (See Tables 1 and 2).

The hydrological modulation technical index is the most important economical irrigation system because it determines the maximum possible source of irrigation.

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It is necessary to achieve the decrease of q within the optimum permissible limit.

The graph hydrological modulation preliminary or incomplete, is characterized by:

Wide variations in the costs ordered when there are momentary highs (peaks) and minimum charges (holes).

Irregularities of the ordinates in time.

Existence of short-term interruptions in the delivery of water for irrigation.

The work of an irrigation system according to this chart of water supply can not be described as satisfactory, therefore takes place entirely on the graph of the final or complete hydrological modulation whose purpose is:

• Reduce the maximum ordinate

• Raising the minimum orders to the value

• Eliminate short-term interruptions in the delivery of water (? Days).

• Level ordinate irregularities.

• The completion of the hydrological modulation performed:

• A consideration of changing the duration of irrigation within the allowable limit without changing the average day of irrigation.

On account of changing irrigation shifts within permissible limits according to agro techniques.

As a result of the completion of the hydrological modulation:

• It rises irrigation capacity of the source of irrigation.

• Costs are reduced maximum rated the irrigation network and therefore reducing their size and their works.

• It improves work of the irrigation network in time.

When complete the graph of hydrological modulation is necessary to:

• Coordinate graphic forms the shape of the graph of expenditure, the expenditure on water supply for irrigation, if it, spending time varies.

• Coordinate with graphic hydrological modulation Working aggregates mechanically pump when water is supplied to the irrigation system.

• Coordinate graphic hydrological modulation the cost of completing the installations and sprinkler irrigation so that the cost of water supplied in accordance with the complete graph are multiples of the cost of irrigation and sprinkler irrigation approved.

Project Location

Once established, the required technical parameters of the irrigation project, the irrigation scheme will be located on the dial 3052 of the flags that holding is supplied by the Dam Las Canoas. It considers the exact location, the lengths of the sprinkler and therefore the areas of the lot in Area 1 is part of irrigation scheme.

• Written by Rajinder Soni.
• In category General.
• 15 years ago.

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