Land management indicators
Fire protection:This indicator is related to the existence of protective infrastructures against forests fires and managed natural resources. The indicator contributes to the definition of the level of control and protective management against forest fire in a territory affected by desertification over a long period. It is assessed by calculating the ratio between surface of forest and other wooded land designated or planned to be protected by infrastructures and natural resources managed against fire vs. the total territorial surface area. The following classes are distinguished: (a) no protection, (b) low protection, < 25 % of total surface protected/total territorial surface; (c) moderate protection, 25 - 50 % of total surface protected/total territorial surface; (d) high protection, 50 - 75% of the total surface protected/total territorial surface; (e) very high protection, >75% of total surface protected/total territorial surface.
Sustainable farming: Sustainable farming is defined as an agricultural system evolving towards greater human utility, increased efficiency of resource use, minimum depletion of non-renewable resources, and environmental interaction favourable to humans and to most other species. The type of sustainable farming is defined for each study field site. Sustainable farming may include actions such as: (i) minimum tillage or non-tillage, (ii) enhancing vegetation cover, (iii) tillage of soil in the up-slope direction, (iv) minimum depth of plowing, etc. Minimum tillage may have favourable effects on soil aggregation and protection of soil crusting and soil erosion. If the soil moisture level is optimal, a minimum tillage is generally favourable because the implements break up the clods, incorporate the organic matter into the soil, kill weeds, and create a more favourable seed bed. Tillage is thus considered necessary in the normal management of some soils. However, frequent tillage operations have detrimental effects on surface soil degradation. In the first place, by mixing and stirring the soil, tillage generally hastens the oxidation of organic matter in soils. Secondly, tillage operations, especially those involving heavy equipment, tend to break down the stable soil aggregates. Maximum soil degradation occurs when a soil is tilled with a mouldboard plow followed by several diskings. In a no-till system, the residues are concentrated on the surface of the soil enhancing aggregate stability and protecting the soil from erosion. Enhancing vegetation cover comprises an effective sediment filter, usable in agricultural and other lands. Many fields cannot be efficiently cropped or, if cropped, are extremely susceptible to erosion. Irregularly shaped and unproductive dry areas can be kept under natural vegetation for controlling runoff and sediment loss.
Reclamation of affected areas: According to UNCCD, the main processes included in National Action Plans as leading to desertification are soil erosion, acidification, salinization and heavy metal contamination. Soils affected by acidification, salinization or heavy metal contamination are considered here as affected areas sensitive to desertification. Such areas can be reclaimed by applying various techniques depending on the degradation process. This indicator is assessed qualitatively subjected to personal judgment or by measuring electrical conductivity of the soil for salt affected soils, concentration of available heavy metals for contaminated soils, and soil pH for acidified soils. The following characterization is followed: no reclamation, adequate drainage, adequate salt leaching, adequate liming of acidified soils, low heavy metals availability.
Reclamation of mining areas; Reclamation of mining areas is defining by evaluating the measurements undertaken for soil erosion control such as terracing, vegetation cover, etc. The following classes are distinguished: (a) no actions undertaken, (b) low, incomplete protection, less than 25% of the area protected; (c) moderate, partial protection, 25-75% of the area protected; (d) adequate, complete protection, >75 of the area protected.
Soil erosion control measures: It includes actions undertaken to reduce soil erosion caused by various factors such as surface water runoff, tillage operations, wind blowing, etc. Soil erosion control measures may include: contour farming, stabilization structures, vegetated waterways, strip cropping, terraces and small water reservoirs. The efficacy of the existing soil erosion control measures are defining on a self explanatory way as following: : (a) no actions undertaken, (b) low, incomplete protection, less than 25% of the area protected; (c) moderate, partial protection, 25-75% of the area protected; (d) adequate, complete protection, >75 of the area protected.
Soil water conservation measures: Soil water conservation techniques may include the following: mulching, weed control, temporary storage of water runoff in small ponds, management of soil surface for maximum water vapour adsorption, cultivation, etc. Considering that the amount of rain occurring under arid or semi-arid climatic conditions is nil compared to the evapotranspiration rates during the dry period (May-October), water vapour adsorption becomes one of the most important source of available water at least for the growing annual vegetation. Under such climatic conditions, soil physical characteristics such as surface mulching, and density of the growing plants greatly affect water vapour adsorption and soil water conservation. Management of the land by (a) reducing the density of the growing vegetation and increasing the soil-atmosphere interface, (b) using surface mulches such as rock fragments or plant residues partially covering the soil surface, and (d) plowing the soil for increasing macroporosity can beneficially and significantly affects water vapour adsorption and soil water conservation. The existing techniques on soil water conservation are recorded for each study site.
Terracing (presence of): Terraces are constructions built mainly in hilly areas to reduce water erosion losses from cultivated erodible soils and for water conservation. Terracing of hilly areas is a measure to combat desertification. Adsorption of water by the soil increases during heavy rainfall events and soil erosion is reduced in terracing land. If terraces are well designed, terraces control sheet and gully erosion by reducing slope length. Water runoff from the upper side of the terraced interval is held within the terrace, infiltrates and it is stored in the soil. The assessment of land terracing is determined by the extent in which an area is covered by terraces. It is defined as the ratio of the area protected to the total area, expressed as a percentage using the following classes: (a) no terracing, (b) low, <25% of the area is protected; (c) moderate, 25-50% of the area is protected; (d) high, 50-75% of the area is protected; (e) very high, >75% of the area is protected. The assessment can be made by: (a) simple field observations, or (b) aerial photographs interpretation.
