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PART B. TECHNOLOGY PROFILES
4.2 Automatic Surge Flow and Gravitational Tank Irrigation Systems
This technology was developed and applied in Mexico during the 1970s. It
is essentially an intermittent gravity-flow irrigation system. It has been
used almost exclusively for small-scale agriculture and domestic
Prior to the development of this technology, electronically controlled
valves were used to produce intermittent water flows for irrigation. These
valves are expensive and require some technical training to operate. The
diabeto (from Greek diabetes or siphon) was developed for the
purpose of replacing these valves with a device that would be more
cost-effective and easier to operate and maintain with a minimum
consumption of energy. The system consists of a storage tank equipped with
one or more siphons, as shown in Figure 37. The storage tank must be
designed to keep a predetermined head in the system to ensure that the
water discharged during the siphoning process does not exceed the water
flow into the storage tank, thereby draining the tank.
Another system that produces similar results is the use of a storage
tank with a bottom discharge. This system as shown in Figure 38, is
equipped with a floater, shown in Figure 39, which allows the cyclical
opening and closing of a gate at the bottom of the tank. In effect, the
operation of the floater is similar to the mechanism in the storage tank
of a toilet flushing system.
The materials normally used in the construction of the water storage
tanks are gravel, cement, and reinforced concrete. The siphons are usually
built of a flexible plastic material; PVC is not recommended.
Figure 37: Schematic of an Automatic Surge Flow
Irrigation System (Diabeto).
Source: P. Martínez
Austria and R.A. Aldama, "Dispositivo de Control para la Aplicación
del Riego Intermitente," Revista Ingeniería Hidráulica
en México, Mayo-Agosto, 1991.
Figure 38: Schematic Representation of a Gravitational
Tank Irrigation System.
Source: V.N. García,
Diseño y Aplicación del Riego Intermitente por Gravedad.
Universidad Nacional Autónoma de México, Facultad de
Ingeniería, México, D.F., 1995, (Tesis para obtener el grado
de Doctor en Ingenieria Hidráulica).
The design of these systems must consider irrigation water use,
available hydraulic load, topographic characteristics in the area of
application, physical dimensions of the irrigated land, slope and location
of furrows, and soil characteristics. Design manuals, based on laboratory
and field experiments, have been developed in Mexico.
Extent of Use
This technology has been used primarily in the arid and semi-arid
regions of Mexico. The diabeto can be used in any gravity irrigation
system, but has been particularly useful in the irrigation of 100 to 300
m2 fields, using furrow irrigation, and in domestic gardening. This
technology is best suited for small-scale (< 4 ha) irrigation in rural
areas. At present, it is widely used only in Mexico.
Operation and Maintenance
The diabeto and the gravitational tanks with bottom discharges
function automatically, based on flow control devices, and do not need
outside energy sources. The water is discharged into a channel that
distributes it into the furrows and to the irrigated crops. Maintenance is
very simple, requiring only periodic cleaning of the tanks, siphons,
and/or discharge pipes.
Level of Involvement
Up to now, educational institutions, small private agricultural
enterprises, and the Mexican Government have promoted this technology.
However, it would be desirable if local communities got more involved in
Figure 39: Schematic Representation of an Automatic Fluid
Water Control Device used in Gravitational Tanks.
V.N. García, Diseño y Aplicación del Riego
Intermitente por Gravedad, Universidad Nacional Autónoma de México,
Facultad de Ingeniería, México, D.F. 1995 (Tesis para
obtener el grado de Doctor en Ingenieria Hidráulica).
A surge flow, automatic irrigation device such as the one shown in
Figure 37 costs about $600. This includes an 11.25 m3 storage tank,
feeding system, and siphon. A device of this size can irrigate up to 4 ha.
A similar gravitational tank irrigation system, with the same tank
capacity, 150 m of piping, and gates, has an estimated cost of $1 500. A
smaller system for domestic gardening can cost around $80. The operation
and maintenance costs of these systems are practically nil. Effectiveness
of the Technology With the surge flow, automatic irrigation systems and
the gravitational tank technologies, irrigation efficiencies of over 75%
have been achieved in the state of Zacatecas, Mexico. This represents a
significant improvement over the 25% rate reported using traditional
irrigation technologies. A saving of about 25% in energy consumption costs
has also been observed.
The technology is recommended for arid and semi-arid areas where low
precipitation and high evaporation rates prevail, and where small storage
areas and depleted aquifers exist.
- This technology can utilize water from small wells of limited
capacity, reused wastewater, and small streams.
- Hydraulic energy is used as the driving force; these systems do not
require external energy sources.
- The systems are low-pressure.
- Irrigation time and labor force requirements are small, as the
systems are automatic. The technology is low in cost.
- It is easy to operate and maintain.
- It is applicable to small-scale agricultural systems.
- It is more efficient than traditional irrigation systems.
- The technology is not recommended for furrow irrigation in fields
with dimensions greater than 200 m long and 25 meters wide, as the
volume of water required in such applications will require extremely
large storage tanks.
- For greater efficiency, the irrigated lands should be leveled.
The technology has been tried and tested in Mexico, although it has the
potential to be used in many other countries. Governments and
international institutions can help disseminate information on its use.
Further Development of the Technology
To improve the applicability of this technology to areas using drip
irrigation, a device that will automatically mix fertilizers into the
water stream provided by the diabeto is under development. Also,
development of modular systems is under way. Ultimately, the development
of educational programs on the implementation and effective use of this
technology will be necessary.
Polioptro Martínez Austria,
Instituto Mexicano de Tecnología del Agua, Coordinación de
Tecnología Hidráulica, Paseo Cuahunáhuac 8532, 62550
Jiutepec, Morelos, México. Tel. (52-73)19-3663. Fax (52-73)20-8725.
Alvaro Aldama Rodriguez, Instituto Mexicano de Tecnología
del Agua, Paseo Cuahunáhuac 8532, 62550 Jiutepec, Morelos, México.
Tel. (52-73)19-3663. Fax (52-73)20-8725.
Nahún García Villanueva, Instituto
Mexicano de Tecnología del Agua, Subcoordinación de Hidráulica
Rural y Urbana, Paseo Cuahunáhuac 8532, 62550 Jiutepec, Morelos,
Mexico. Tel. (52-73)19-4000, ext. 510.
José Natividad Barrios Domínguez,
Universidad Autónoma de Zacatecas, Facultad de Ingeniería,
Bishop, A.A., et al. 1981. "Furrow Advance Rates Under Surge Flow
Systems." Journal Irrigation and Drainage, vol. 107, IR3.
Biswas, A.K. 1992. "Sustainable Water Development: a Global
Perspective," Water International, 17(2).
-. 1995. "Institutional Arrangements for International Cooperation
in Water Resources," International Journal of Water Resources
Development, 11(2). FAO. 1990. An International Action Programme on
Water and Sustainable AgricultuGarcía, V.N. 1995. Diseño
y Aplicación del Riego Intermitente por Gravedad. México,
D.F., Universidad Nacional Autónoma de México, Facultad de
Ingeniería. (Tesis para obtener el grado de Doctor en Ingenieria
Jensen, M.E. 1990. "Arid Lands Impending Water Population Crises."
In Proceedings of the ASCE International Symposium on
Hydraulics/Hydrology of Arid Lands, (San Diego, Cal.). Reston, VA.,
Martínez Austria, P. 1994. "Efficient Use of Irrigation
Water." In Garduño and Arreguin (eds.), Efficient Water
Use, Chapter 4. Urbana, Ill., International Water Resources
-, and R. A. Aldama. 1990. "A Simple Fluidic Device for Surge Flow
Irrigation." Paper presented to the XXIV Congress of the
International Association for Hydraulic Research, Madrid. 9-13 September.
-, and -. 1990. Dispositivo Fluídico para Riego
Intermitente, Jiutepec, Morelos, México, Instituto Mexicano de
Tecnología del Agua. (Serie Divulgación, No. 26) -, and
-. 1991. "Dispositivo de Control para la Aplicación del Riego
Intermitente." Revista Ingeniería Hidráulica en México,
Schiller, E.J. 1992. "Water Resources: An Emerging Crisis.
Sustainable Water Resources Management in Arid Countries," Canadian
Journal of Development Studies, Special Issue, pp. 7-12.
Stringham, G.E., and J. Keller. 1979. "Surge Flow Automatic
Irrigation." Paper presented to the ASCE Irrigation and Drainage
Specialty Conference, Albuquerque, N.M., U.S.A.