A Liman (from Greek λιμήν) in

Israel Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...

is the name for an artificial earthen construction used to collect floodwater by damming a desert

wadi Wadi ( ar, وَادِي, wādī), alternatively ''wād'' ( ar, وَاد), North African Arabic Oued, is the Arabic term traditionally referring to a valley. In some instances, it may refer to a wet (ephemeral) riverbed that contains water onl ...

. The runoff water is slowed by the dam, thus flooding a small area and allowing the water to infiltrate into the soil. This way, a small groves of trees can be sustained in the desert. The

JNF-KKL Jewish National Fund ( he, קֶרֶן קַיֶּימֶת לְיִשְׂרָאֵל, ''Keren Kayemet LeYisrael'', previously , ''Ha Fund HaLeumi'') was founded in 1901 to buy and develop land in Ottoman Syria (later Mandatory Palestine, and subseq ...

has been funding the construction of limans in the Negev Desert.

Introduction

Limans were built in order to fight

desertification Desertification is a type of land degradation in drylands in which biological productivity is lost due to natural processes or induced by human activities whereby fertile areas become increasingly arid. It is the spread of arid areas caused by ...

without depleting

groundwater Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...

resources, which are becoming increasingly rare in arid ecosystems.Prinz, D. 2002. The role of water harvesting in alleviating

water scarcity Water scarcity (closely related to water stress or water crisis) is the lack of fresh water Water resources, resources to meet the standard water demand. There are two types of water scarcity: physical or economic water scarcity. Physical water ...

in arid areas. In Proceedings, International Conference on Water Resources Management in Arid Regions. 23–27 March 2002, 107–122. Kuwait: Kuwait Institute for Scientific Research Available at: Remaining soil humidity can be found in dry river beds (

wadis Wadi ( ar, وَادِي, wādī), alternatively ''wād'' ( ar, وَاد), North African Arabic Oued, is the Arabic term traditionally referring to a valley. In some instances, it may refer to a wet (ephemeral) riverbed that contains water o ...

) after

rain Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...

s occur, but these

are prone to

flash floods A flash flood is a rapid flooding of low-lying areas: washes, rivers, dry lakes and depressions. It may be caused by heavy rain associated with a severe thunderstorm, hurricane, or tropical storm, or by meltwater from ice or snow flowing o ...

. The result is massive

soil erosion Soil erosion is the denudation or wearing away of the upper layer of soil. It is a form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, air (wind), plants, and ...

and the destruction of infrastructure. Also, the infiltration is insufficient because of the water's velocity, even though the runoff would be able to allow for the growth of trees in appropriate places. The aim of building limans is to stop flash floods and to increase water infiltration, thus sustaining the

growth Growth may refer to: Biology * Auxology, the study of all aspects of human physical growth * Bacterial growth * Cell growth * Growth hormone, a peptide hormone that stimulates growth * Human development (biology) * Plant growth * Secondary growth ...

of drought-hardy

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

and

vegetation Vegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic character ...

underneath them.

Design

Limans are structures with small dams which catch runoff from a wadi to hold about 400-600mm of water, which suffices for the growth of drought-hardy tree species. Limans can be built ''wherever tributary wadis ..widen or come onto a large plain with potential

arable land Arable land (from the la, arabilis, "able to be ploughed") is any land capable of being ploughed and used to grow crops.''Oxford English Dictionary'', "arable, ''adj''. and ''n.''" Oxford University Press (Oxford), 2013. Alternatively, for the ...

.. A check-dam ..is built to retain runoff waters .. A

spillway A spillway is a structure used to provide the controlled release of water downstream from a dam or levee, typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure tha ...

regulates the level of the water ..to prevent the destruction of the check-dam.''. The

embankment Embankment may refer to: Geology and geography * A levee, an artificial bank raised above the immediately surrounding land to redirect or prevent flooding by a river, lake or sea * Embankment (earthworks), a raised bank to carry a road, railwa ...

height should be 3–4 times the designed water depth, and the outlet should be to the side of the main flow to prevent direct through flow. Also, grazers should be excluded from the site to prevent

soil compaction In geotechnical engineering, soil compaction is the process in which stress applied to a soil causes densification as air is displaced from the pores between the soil grains. When stress is applied that causes densification due to water (or other ...

which would in turn decrease

water infiltration Infiltration is the process by which water on the ground surface enters the soil. It is commonly used in both hydrology and soil sciences. The infiltration capacity is defined as the maximum rate of infiltration. It is most often measured in meter ...

Suitable tree species

Because of its fast growth, '' Eucalyptus occidentalis'' was mostly used in the past. However, some scientific studies have had better results with ''

Eucalyptus sargentii ''Eucalyptus sargentii'', commonly known as Salt River gum, is a species of mallet, mallee or small tree that is endemic to Western Australia. It has rough bark on part or all of the trunk, smooth bark above, linear to narrow lance-shaped leav ...

''.Brunori, A., Nair, P.K.R., & Rockwood, D.L. 1995. Performance of two Eucalyptus species at different slope positions and aspects in a contour-ridge planting system in the Negev Desert of Israel. ''Forest Ecology and Management'' (75): p.41–48
PDF
/ref> Overall, any drought-hardy species are suitable, such as

tamarind Tamarind (''Tamarindus indica'') is a Legume, leguminous tree bearing edible fruit that is probably indigenous to tropical Africa. The genus ''Tamarindus'' is monotypic taxon, monotypic, meaning that it contains only this species. It belongs ...

acacia ''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus na ...

prosopis ''Prosopis'' is a genus of flowering plants in the family Fabaceae. It contains around 45 species of spiny trees and shrubs found in subtropical and tropical regions of the Americas, Africa, Western Asia, and South Asia. They often thrive in ari ...

pistachio The pistachio (, ''Pistacia vera''), a member of the cashew family, is a small tree originating from Central Asia and the Middle East. The tree produces seeds that are widely consumed as food. ''Pistacia vera'' is often confused with other sp ...

eucalyptus ''Eucalyptus'' () is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with several other genera in the tribe Eucalypteae, including '' Corymbia'', they are commonly known as euca ...

date palm ''Phoenix dactylifera'', commonly known as date or date palm, is a flowering plant species in the palm family, Arecaceae, cultivated for its edible sweet fruit called dates. The species is widely cultivated across northern Africa, the Middle Eas ...

and

carob The carob ( ; ''Ceratonia siliqua'') is a flowering evergreen tree or shrub in the Caesalpinioideae sub-family of the legume family, Fabaceae. It is widely cultivated for its edible fruit pods, and as an ornamental tree in gardens and landscap ...

Effects

Before the invention of Limans, their creators as well as scientists expected several positive and/or negative impacts: * They expected a negative soil salinisation due to salt deposition and/or high evaporation rates. This was not the case.Ffolliott, P.F. et al. 2000. International Arid Lands Consortium: Better Land Stewardship in Water and Watershed Management. USDA Forest Service Proceedings – Rocky Mountains Research Centre P-13: p.335–338. http://www.fs.fed.us/rm/pubs/rmrs_p013/rmrs_p013_335_338.pdf *

Carbon sequestration Carbon sequestration is the process of storing carbon in a carbon pool. Carbon dioxide () is naturally captured from the atmosphere through biological, chemical, and physical processes. These changes can be accelerated through changes in land ...

: Because of the biomass increase, a CO₂ uptake is expected.No literature could be found as of June 2012, which suggests that the issue might not have been studied yet. * Scientists were hoping for a

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Eart ...

uptake, but it could not be measured in limans. Instead, they found a shallow zone of methane production.Angel, R., & Conrad, R. 2009. In situ measurement of methane fluxes and analysis of transcribed particulate methane monooxygenase in desert soils. Environmental Microbiology 11(10): p.2598–2610. http://onlinelibrary.wiley.com/doi/10.1111/j.1462-2920.2009.01984.x/abstract * Because desert crusts prevent rainwater from infiltrating the ground, they generate surface run-off that can lead to flash floods and to top-soil erosion. Limans prevent both the loss of

surface runoff Surface runoff (also known as overland flow) is the flow of water occurring on the ground surface when excess rainwater, stormwater, meltwater, or other sources, can no longer sufficiently rapidly infiltrate in the soil. This can occur when th ...

and of

topsoil Topsoil is the upper layer of soil. It has the highest concentration of organic matter and microorganisms and is where most of the Earth's biological soil activity occurs. Description Topsoil is composed of mineral particles and organic matt ...

, as well as plant nutrients. On top of that, they provide a controlled place to deposit these resources. * So far, no ecological research has been conducted on

biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species (''species diversity''), and ecosystem (''ecosystem diversity'') l ...

within limans.

References

{{reflist Oases of Israel Negev

Introduction

Design

Suitable tree species

Effects

See also

References