A semi-circular bund (also known as a demi-lune or half-moon) is a rainwater harvesting technique consisting in digging semilunar holes in the ground with the opening perpendicular to the flow of water. [1] [2]
These holes are oriented against the slope of the ground, generating a small dike in the curved area with the soil from the hole itself, so they capture the rainwater running downhills. [3]
These structures allow water to seep into the soil, retaining in the subsoil a greater amount of moisture. But also, it prevents the loss of fertile soil. [4]
Semi-circular bunds are used to reforest arid zones with irregular rain patterns, allowing the growth of plants and trees, such as in the Sahel. [5]
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 arid. It is the spread of arid areas caused by a variety of factors, such as overexploitation of soil as a result of human activity and the effects of climate change. Geographic areas most affected include the Sahel region in Africa, the Gobi Desert and Mongolia in Asia as well as parts of South America. Drylands occupy approximately 40–41% of Earth's land area and are home to more than 2 billion people.
Energy-efficient landscaping is a type of landscaping designed for the purpose of conserving energy. There is a distinction between the embedded energy of materials and constructing the landscape, and the energy consumed by the maintenance and operations of a landscape.
Horticulture is the cultivation of plants in gardens or greenhouses, as opposed to the field-scale production of crops characteristic of agriculture. It includes the cultivation of fruits, vegetables, nuts, seeds, herbs, sprouts, mushrooms, algae, flowers, seaweeds and non-food crops such as grass and ornamental trees and plants. It also includes plant conservation, landscape restoration, landscape and garden design, construction, and maintenance, and arboriculture, ornamental trees and lawns.
A mulch is a layer of material applied to the surface of soil. Reasons for applying mulch include conservation of soil moisture, improving fertility and health of the soil, reducing weed growth, and enhancing the visual appeal of the area.
Water conservation includes all the policies, strategies and activities to sustainably manage the natural resource of fresh water, to protect the hydrosphere, and to meet the current and future human demand. Population, household size and growth and affluence all affect how much water is used. Factors such as climate change have increased pressures on natural water resources especially in manufacturing and agricultural irrigation. Many countries have already implemented policies aimed at water conservation, with much success. The key activities to conserve water are as follows: any beneficial reduction in water loss, use and waste of resources, avoiding any damage to water quality; and improving water management practices that reduce the use or enhance the beneficial use of water. Technology solutions exist for households, commercial and agricultural applications. Water conservation programs involved in social solutions are typically initiated at the local level, by either municipal water utilities or regional governments.
Dryland farming and dry farming encompass specific agricultural techniques for the non-irrigated cultivation of crops. Dryland farming is associated with drylands, areas characterized by a cool wet season followed by a warm dry season. They are also associated with arid conditions, areas prone to drought and those having scarce water resources.
Rainwater harvesting (RWH) is the collection and storage of rain, rather than allowing it to run off. Rainwater is collected from a roof-like surface and redirected to a tank, cistern, deep pit, aquifer, or a reservoir with percolation, so that it seeps down and restores the ground water. Dew and fog can also be collected with nets or other tools. Rainwater harvesting differs from stormwater harvesting as the runoff is typically collected from roofs and other surfaces for storage and subsequent reuse. Its uses include watering gardens, livestock, irrigation, domestic use with proper treatment, and domestic heating. The harvested water can also be committed to longer-term storage or groundwater recharge.
Biological soil crusts are communities of living organisms on the soil surface in arid and semi-arid ecosystems. They are found throughout the world with varying species composition and cover depending on topography, soil characteristics, climate, plant community, microhabitats, and disturbance regimes. Biological soil crusts perform important ecological roles including carbon fixation, nitrogen fixation and soil stabilization; they alter soil albedo and water relations and affect germination and nutrient levels in vascular plants. They can be damaged by fire, recreational activity, grazing and other disturbances and can require long time periods to recover composition and function. Biological soil crusts are also known as biocrusts or as cryptogamic, microbiotic, microphytic, or cryptobiotic soils.
Rain gardens, also called bioretention facilities, are one of a variety of practices designed to increase rain runoff reabsorption by the soil. They can also be used to treat polluted stormwater runoff. Rain gardens are designed landscape sites that reduce the flow rate, total quantity, and pollutant load of runoff from impervious urban areas like roofs, driveways, walkways, parking lots, and compacted lawn areas. Rain gardens rely on plants and natural or engineered soil medium to retain stormwater and increase the lag time of infiltration, while remediating and filtering pollutants carried by urban runoff. Rain gardens provide a method to reuse and optimize any rain that falls, reducing or avoiding the need for additional irrigation. A benefit of planting rain gardens is the consequential decrease in ambient air and water temperature, a mitigation that is especially effective in urban areas containing an abundance of impervious surfaces that absorb heat in a phenomenon known as the heat-island effect.
In hydrology, oasification is the antonym to desertification by soil erosion. This technique has limited application and is normally considered for much smaller areas than those threatened by desertification.
A taanka or paar, is a traditional rainwater harvesting technique, common to the Thar desert region of Rajasthan, India. It is meant to provide drinking water and water security for a family or a small group of families. A taanka is composed of a covered, underground, impermeable cistern on shallow ground for the collection of rainwater. The cistern is generally constructed out of stone or brick masonry, or concrete, with lime mortar or cement plaster. Rainwater or surface run-off from rooftops, courtyards, or artificially prepared catchments flow into the tank through filtered inlets in the wall of the pit.
Sustainable landscaping is a modern type of gardening or landscaping that takes the environmental issue of sustainability into account. According to Loehrlein in 2009 this includes design, construction and management of residential and commercial gardens and incorporates organic lawn management and organic gardening techniques.
Sand dams are a simple, low-cost and low-maintenance, replicable rainwater harvesting technology. They provide a clean, local water supply for domestic and farming use and are suited to semi-arid areas of the world.
Desert greening is the process of afforestation or revegetation of deserts for ecological restoration (biodiversity), sustainable farming and forestry, but also for reclamation of natural water systems and other ecological systems that support life. The term "desert greening" is intended to apply to both cold and hot arid and semi-arid deserts. It does not apply to ice capped or permafrost regions. It pertains to roughly 32 million square kilometres of land. Deserts span all seven continents of the Earth and make up nearly a fifth of the Earth's landmass, areas that recently have been increasing in size. As some of the deserts expand and global temperatures increase, the different methods of desert greening may provide a potential solution. Planting suitable flora in deserts has a range of environmental benefits from carbon sequestration to providing habitat for native desert fauna to generating employment opportunities to creation of habitable areas for local communities. The prevention of land desertification is one of 17 sustainable development objectives outlined by the United Nations, desert greening is a process that aims to not only combat desertification but to foster an environment where plants can create a sustainable environment for all forms of life while preserving its integrity.
Stormwater harvesting or Stormwater reuse is the collection, accumulation, treatment or purification, and storage of stormwater for its eventual reuse. While rainwater harvesting collects precipitation primarily from rooftops, stormwater harvesting deals with collection of runoff from creeks, gullies, ephemeral streams, underground conveyances. It can also include catchment areas from developed surfaces, such as roads or parking lots, or other urban environments such as parks, gardens and playing fields.
Water storage is a broad term referring to storage of both potable water for consumption, and non potable water for use in agriculture. In both developing countries and some developed countries found in tropical climates, there is a need to store potable drinking water during the dry season. In agriculture water storage, water is stored for later use in natural water sources, such as groundwater aquifers, soil water, natural wetlands, and small artificial ponds, tanks and reservoirs behind major dams. Storing water invites a host of potential issues regardless of that water's intended purpose, including contamination through organic and inorganic means.
Land surface effects on climate are wide-ranging and vary by region. Deforestation and exploitation of natural landscapes play a significant role. Some of these environmental changes are similar to those caused by the effects of global warming.
Melesse Temesgen is an Ethiopian agricultural engineer, hydrologist and businessman. He was born on 7 July 1964 in Gojjam, Ethiopia. He is the CEO of Aybar Engineering PLC.
Rainwater management is a series of countermeasures to reduce runoff volume and improve water quality by replicating the natural hydrology and water balance of a site, with consideration of rainwater harvesting, urban flood management and rainwater runoff pollution control.
Rainwater harvesting in the Sahel is a combination of "indigenous and innovative" agricultural strategies that "plant the rain" and reduce evaporation, so that crops have access to soil moisture for the longest possible period of time. In the resource-poor drylands of the Sahel region of Africa, irrigation systems and chemical fertilizers are often prohibitively expensive and thus uncommon: so increasing or maintaining crop yields in the face of climate change depends on augmenting the region's extant rainfed agriculture systems to "increase water storage within the soil and replenish soil nutrients." Rainwater harvesting is a form of agricultural water management. Rainwater harvesting is most effective when combined with systems for soil regeneration and organic-matter management.