A procedure for such site assessment has been described by Hall and Thompson 1981 and, if applied, should not only allow the most suitable site among several possible to be selected but permit the impact of effluent irrigation at the chosen site to be modelled. In many areas, other sources of irrigation have been adopted and the dry beds of tanks have been reclaimed for agriculture. The Saran 66 km , the Tirahut 257 km , Dun 95 km , Nepal east 80. At that time, there were fewer than half the current number of people on the planet. This is called on-stream storage see Figure 11. This method should be adopted only when other flooding methods are impossible. This canal will be built at a uniform height of only 500 metres; and it will be more than twice as long encircling the entire southern and central plateau.
This underground water, when under natural pressure, may be pushed up to the surface to form springs, which provide water to rivers and lakes. Slope may be related to discharge as follows. Millions of of all sizes are currently extracting groundwater throughout the world. In general, the goal is to supply the entire field uniformly with water, so that each plant has the amount of water it needs, neither too much nor too little. The sub-soil water is exploited through deep well pumping. Several alternatives are available and a combination of these alternatives will offer an optimum solution for a given set of conditions.
Water stress Main articles: and The concept of water stress is relatively simple: According to the , it applies to situations where there is not enough water for all uses, whether agricultural, industrial or domestic. If the surface water source is also subject to substantial evaporation, a groundwater source may become. Role in new agricultural strategy : The successful implementation of the High Yielding Programme enhances agricultural production to a great entent. Perforated Fixed Pipe Sprinklers: In this method parallel pipes are installed at a suitable spacing say 15 m and supported on the posts. Fertilizers are used economically since they can be injected through the water. A toxicity problem is different from a salinity problem in that it occurs within the plant itself and is not caused by water shortage.
The advantage of deep furrow is that in initial stages the roots are not damaged. Fields with irregular shapes are easily accommodated. It provides irrigation to about 4. In this method it is possible to maintain more discharges successfully. Deep furrow irrigation system is generally used for sugar cane, orchards, and some field crops also. What is important is to maintain a downward movement of water through soils. Sprinkler System This is an irrigation system based on overhead sprinklers, sprays or guns, installed on permanent risers.
After elimination of marginal sites , each site under serious consideration must be investigated by on-site borings to ascertain the soil profile, soil characteristics and location of the water table. Due to the low water level, pumps will normally be needed to irrigate fields from such a reservoir Figure 13. The Project envisages the construction of two mammoth canals, the Himalayan Catchment Canal and the Central Deccan and Southern Plateau Canal, spanning the length and breadth of the country. It is unsuitable for crops that are sensitive to water logging the method suitable where broadcast crops, particularly pastures, alfalfa, peas and small grains are produced. This may have drawbacks in areas having a high water table, which allows secondary salinization between pondings, vi.
Recreational usage is usually non-consumptive. Flood irrigation - water is applied over the entire field to infiltrate into the soil e. In Madhya Pradesh, Bihar, Haryana. In those instances, where soil salinity cannot be maintained within acceptable limits of preferred sensitive crops, changing to more tolerant crops will raise the area's production potential. If there is any doubt about the effect of wastewater salinity on crop production, a pilot study should be undertaken to demonstrate the feasibility of irrigation and the outlook for economic success.
Management of water, soil, crop and operational procedures, including precautions to protect farm workers, play an important role in the successful use of sewage effluent for irrigation. Good method where power costs are low. Evaporation from open water can easily reach 7 mm per day in arid or semi-arid countries. Inland groundwater may also be brackish in places where the soil contains many soluble salts. International Association of Hydrological Science. Deep or slip ploughing is costly and usually requires the growing of annual crops soon after to allow the settling of the land. Lateral lines can be up to about 50 meters long and are usually 1.
Several cultural and crop management practices that are valid under saline water use will be valid under wastewater use. Drip systems can provide the best uniformity but require the most materials. Water stress can also exacerbate conflicts and tensions which are not directly caused by water. Steeper slopes may also be adopted, but then it is necessary to see that the water is not overflowing the banks of furrows. The rate of delivery of effluent either as m 3 per day or litres per second.
Further, by blending, the microbial quality of the resulting mixture could be superior to that of the unblended wastewater. Water and conflicts Main article: Competition for water has widely increased, and it has become more difficult to conciliate the necessities for water supply for human consumption, food production, ecosystems and other uses. Mode of supply: supply at farm gate or effluent available in a storage reservoir to be pumped by the farmer. Irrigation also has other uses in crop production, including frost protection, suppressing weed growth in grain fields and preventing. Length of furrows may be up to 800 m for field crops, about 30 m or less for gardens. In arid areas, the importance of agricultural use of treated effluent makes it advisable to be as systematic as possible in planning, developing and managing effluent irrigation projects and the public must be kept informed at all stages. Crop evapotranspiration is mainly determined by climatic factors and hence can be estimated with reasonable accuracy using meteorological data.