__NOTOC__{{Language-box|english_link=Water Portal / Rainwater Harvesting / In situ rainwater harvesting | french_link=La collecte des eaux de pluie in situ | spanish_link=Captación de agua de lluvia in situ | hindi_link=वाटर पोर्टल / वर्षाजल संचयन / यथास्थान वर्षाजल संचयन | malayalam_link=Coming soon|tamil_link=Coming soon | korean_link=원위치 빗물 집수 | chinese_link=原地集雨 | indonesian_link=Panen Air Hujan / Panen Air Hujan Langsung in Situ | japanese_link=In situ雨水貯留}} [[Image:in situ2In situ - rainwater harvesting.jpg|thumb|right|250px200px|In situ rainwater harvesting in Jodhpur, Rajasthan. Photo: [http://www.greenfieldeco.com/photogallery.php Greenfield Eco Solutions Pvt. Ltd]]]In arid and semi-arid regions, where precipitation is low or infrequent during the dry season, it is necessary to store the maximum amount of rainwater during the wet season for use at a later time, especially for agricultural and domestic water supply. One of the methods frequently used in rainwater harvesting is the storage of rainwater '''in situ'''. Topographically low areas are ideal sites for in situ harvesting of rainfall. This technique has been used in the arid and semi-arid regions of northeastern Brazil, Argentina, and Paraguay, primarily for irrigation purposes. The in situ technology consists of making storage available in areas where the water is going to be utilized.
Generally this technology is simple and easy to use. Governmental organizations and the agricultural community generally work together to support and promote the in situ rainwater storage. Educational and information programs should be provided to inform users of the benefits of this technology, and the means of implementing rainwater harvesting while preventing soil loss.
===Suitable conditions===This technology is applicable to low topographic areas increases water supply for irrigation purposes in arid or and semi-arid climatesregions. It promotes improved management practices in the cultivation of corn, cotton, sorghum, and many other crops. It also provides additional water supply for livestock watering and domestic consumption.
In situ technology has been extensively used is applicable to low topographic areas in arid or semi-arid climates. Extensive use is found in northeastern Brazil, in the Chaco region of Paraguay, and in Argentina. It can be used to augment the water supply for crops, livestock, and domestic use. With the mechanization of agriculture, its use has diminished, but it is still recommended for regions where the volume of rainfall is small and variable. The approach used depends primarily on the availability of equipment, the nature of the agricultural and livestock practices, and the type of soil.
'''Cultural Acceptability'''<br>
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===Design & design limitations, construction===
All rainfall harvesting systems have three components: a collection area, a conveyance system, and a storage area. In this application, collection and storage is provided within the landscape. Topographic depressions represent ideal collection and storage areas. In many situations, such areas are impermeable, being underlain by clay soils that minimize infiltration. Methods of rainwater harvesting in situ, including site preparation of agricultural areas in Brazil, are described below.
====Use of Furrows as Rainwater Storage Areas====
[[Image:furrowRainwater Furrow.jpg|thumb|right|250px|Half-moon furrows around newly planted Acacia seedlings catch and retain rainwater. Photo: [http://www.fao.org/docrep/009/a0100e/a0100e07.htm FAO] - T.F. SHAXSON]]
Furrows may be used as an in situ means of storing harvested rainwater. They are built prior to or after planting to store water for future use by the plants. A variation on the use of topographic depressions to store rainfall, this method uses flattened trenches between the rows of crops to store water. Furrows may have mud dams or barriers every 2 m to 3 m along the row in order to retain water for longer periods of time and avoid excessive surface runoff and erosion. Raised beds may also be used to trap the water in the furrows, or uncultivated areas may be left between rows, spaced at 1 m apart, to assist in capturing rainwater falling on the land surface between furrows.
The Guimarães Duque method was developed in Brazil during the 1950s, and uses furrows and raised planting beds, on which cross cuts to retain water are made using a reversible disk plow with at least three disks. The furrows are usually placed at the edge of the cultivation zone.
===Costs, operation & maintenance===
This technology requires very little '''maintenance''' once the site is chosen and prepared. Maintenance is done primarily during the course of normal, day-to-day agricultural activities, and consists primarily of keeping the collection area free of debris and unwanted vegetation. Where only parts of the rows are cultivated, rotating the areas that are plowed will enable more efficient maintenance of the available storage area.
'''Table 1. Estimated Cost ($) of Different Site Preparation Methods for Rainwater Collection Areas in Agricultural Areas of Brazil.'''
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The equipment used in the construction of the furrows and storage areas must be improved. Relatively inexpensive plows and tractors can reduce the cost of implementation and contribute to the more widespread use of this technology by small farmers. New methods of soil conservation should be explored.
===Manuals, videos, and links===
====Contacts====
*
'''José Barbosa dos Anjos
''', Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Centro de Pesquisa Agropecuaria do Trópico Semi-Árido (CPATSA), BR-428 km 152, Zona Rural, Caixa Postal 23, 56300-000 Petrolina, Pernambuco, Brasil. Tel. (55-81)862-1711. Fax (55-81)862-1744. E-mail: jbanjos
@cpatsa.embrapa.br. * '''Everaldo Rocha Porto''', Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Centro de Pesquisa Agropecuaria do Trópico Semi-Árido (CPATSA), BR-428 km 152, Zona Rural, Caixa Postal 23, 56300-000 Petrolina, Pernambuco, Brasil. Tel. (55-81)862-1711. Fax (55-81)862-1744. E-mail: [email protected]. * '''Luiza Teixeira de Lima Brito''', Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Centro de Pesquisa Agropecuaria do Trópico Semi-Árido (CPATSA), BR-428 km 152, Zona Rural, Caixa Postal 23, 56300-000 Petrolina, Pernambuco, Brasil. Tel. (55-81)862-1711. Fax (55-81)862-1744. E-mail: luizatlb@cpatsa.embrapa.br.
*
Everaldo Rocha Porto'''Eduardo Torres''',
Empresa Brasileira Instituto Argentino de
Pesquisa Agropecuaria Investigaciones de las Zonas Aridas (
EMBRAPAIADIZA),
Centro Dependiente del Consejo Nacional de
Pesquisa Agropecuaria do Trópico Semi-Árido Ciencia y Tecnologia (
CPATSACONICET),
BR-428 km 152Universidad Nacional de Cuyo y Gobierno de la Provincia de Mendoza,
Zona RuralCasilla de Correo 507,
Caixa Postal 235500 Mendoza,
56300-000 Petrolina, Pernambuco, Brasil. Tel. (55-81)862-1711República Argentina. Fax (
5554-
8161)
862-1744. E-mail: [email protected]287955.
* Luiza Teixeira de Lima Brito'''Maria Sonia Lopes da Silva''', Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Centro de Pesquisa Agropecuaria do Trópico Semi-Árido (CPATSA), BR-428 km 152, Zona Rural, Caixa Postal 23, 56300-000 Petrolina, Pernambuco, Brasil. Tel. (55-81)862-1711. Fax (55-81)862-1744. E-mail: luizatlbsoniag@cpatsa.embrapa.br.
* Eduardo Torres'''Aderaldo de Souza Silva''', Instituto Argentino Empresa Brasileira de Investigaciones de las Zonas Aridas Pesquisa Agropecuaria (IADIZAEMBRAPA), Dependiente del Consejo Centro Nacional de Ciencia y Tecnologia Pesquisa de Monitoramento e Avaliacao de Impacto Ambientalt (CONICETNPMA), Universidad Nacional de Cuyo y Gobierno de la Provincia de MendozaRodovia SP-340 km 127.5, Bairro Tanquinho Velho, Caixa Postal 69, Casilla de Correo 50713820-000 Jaguariuna, 5500 MendozaSão Paulo, República ArgentinaBrasil. Tel.(55-4198)67-5633. Fax (5455-614198)28795567-5225.
* Maria Sonia Lopes da Silva, Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Centro de Pesquisa Agropecuaria do Trópico Semi-Árido (CPATSA), BR-428 km 152, Zona Rural, Caixa Postal 23, 56300-000 Petrolina, Pernambuco, BrasilLarge wiki on water use for agriculture: [http://web. Telarchive. (55-81)862-1711. Fax (55-81)862-1744. E-mailorg/web/20151025174729/http: soniag@cpatsa//agropedia.embrapaiitk.brac.in:80/ Agropedia]
* Aderaldo de Souza Silva, Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Centro Nacional de Pesquisa de Monitoramento e Avaliacao de Impacto Ambientalt (NPMA), Rodovia SP===Acknowledgements===[http://www.oas.org/dsd/publications/Unit/oea59e/begin.htm#Contents Source Book of Alternative Technologies for Freshwater Augmentation in Latin America and the Caribbean]. 1.2 Rainwater harvesting in situ. UNEP -340 km 127International Environmental Technology Centre United Nations Environment Programme.5, Bairro Tanquinho VelhoUnit of Sustainable Development and Environment General Secretariat, Caixa Postal 69Organization of American States, 13820-000 JaguariunaWashington, São Paulo, BrasilD. TelC.(55-4198)67-5633. Fax (55-4198)67-5225, 1997.