How can degradation be limited

Omuto, C. Land degradation assessment and a monitoring framework in Somalia. Soil erosion and sedimentation modelling and monitoring of the areas between rivers juba and Shabelle in southern Somalia. Somalia Water and Land Information Management. Ravi, S. Land degradation in drylands: Interactions among hydrologic—aeolian erosion and vegetation dynamics. Geomorphology, , Riva, M. Assessment of land degradation in Mediterranean forests and grazing lands using a landscape unit approach and the normalized difference vegetation index.

Applied geography, 86, Scholes, R. A biodiversity intactness index. Nature, , Sonneveld, B. Quantifying the impact of land degradation on crop production: the case of Senegal. Solid Earth, 7 1 , Stockholm Environment Institute. Sutton, P. The ecological economics of land degradation: Impacts on ecosystem service values.

Ecological Economics, , Taelman, S. Accounting for land use in life cycle assessment: the value of NPP as a proxy indicator to assess land use impacts on ecosystems.

Science of the Total Environment, , Tagore, G. Mapping of degraded lands using remote sensing and GIS techniques. Journal of Agricultural Physics, 12 1 , Tanser, F. The application of a remotely-sensed diversity index to monitor degradation patterns in a semi-arid, heterogeneous, South African landscape.

Journal of arid environments, 43 4 , Thiam, A. Toensmeier, E. The carbon farming solution: a global toolkit of perennial crops and regenerative agriculture practices for climate change mitigation and food security. Chelsea Green Publishing. Torrion, J. Land degradation detection, mapping and monitoring in the Lake Naivasha Basin, Kenya.

Tun, K. Assessment of land degradation and its impact on crop production in the Dry Zone of Myanmar. Land in Numbers Risks and Opportunities. Land Degradation and Migration: Will restoring the land keep people at home? Vargas, R. Vicente-Serrano, S. Drought variability and land degradation in semiarid regions: Assessment using remote sensing data and drought indices — Remote Sensing, 7 4 , Vieira, R. Identifying areas susceptible to desertification in the Brazilian northeast.

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Data Application of the Month: Land Degradation. Image: Nachtergaele et al. Table of contents 1. Application of land degradation information for disaster risk management References 1. Land degradation and the disaster management cycle 1.

Deforestation, flooding, landslides Soil degradation is a common feature of LD both as a cause and an effect of the LD process. Drought and human security Soil erosion and salinization - mostly caused by poor irrigation practices - can result in drought and famine episodes if unchecked in time. Climate change and food security Climate change is one of the leading causes of loss of biodiversity and ecosystem balance and function.

How to monitor and assess land degradation from space The basic process of land degradation management involves three steps: assessment, monitoring and implementation of appropriate mitigation measures. Approaches Normalized Difference Vegetation Index NDVI This is a basic measure of vegetation condition and health indicating the quality, quantity and development of vegetation in a given area. Image: Parmehr, E. Estimation of urban tree canopy cover using random point sampling and remote sensing methods.

Image: Mbatha, N. Climate, 6 4 , Change detection Change detection uses images taken at different time periods - usually Date 1 taken before the assessment period and Date 2 taken after the assessment period. Indicator monitoring Different features reflect electromagnetic energy in different signatures and thus can be identified and extracted using different feature extraction methods and software. Some of the indicators used for land degradation monitoring include, but are not limited to: Development of long-term surface features such as gullies, rills, sand dunes, badlands, salt crusts and other detectable soil surface salinity features, etc.

Condition and spatial variability of natural vegetation, crop cover, soil, erosion features such as gullies, etc Metternicht et al. Most soil indicators need to be assessed using hyper-spectral data which is currently expensive to obtain and can only be used for small areas. Vegetation indicators on the other hand have been used for a long time now and thus have much developed methodologies and easily accessible data sources.

Medium and coarse resolution satellite data, such as Landsat and MODIS, are the common data sets used for this purpose. Vegetation greenness, cover extent and biomass are some of the common proxies used to assess land degradation. Floods and landslides Floods and landslides can indicate locations where degradation is likely to occur firstly due to the indiscriminate sweeping action of the two forces, washing away vegetation and fertile top soils.

Other methods Rain Use Efficiency RUE , defined as the ratio of net primary productivity to precipitation over a given time Dubovyk, ; Tagore et al. The GLADA approach, a sequence of analyses: 1 calculate NDVI for mean annual and trend biomass productivity, 2 then integrating the result with climate data rain use efficiency and thereafter 3 linking it to net land productivity calculate changes in biomass production for dominant land use types , 4 finally land stratification based on land cover, soil and terrain data.

The table below gives an overview of some of the land degradation indicators or proxies and the studies that have used each of the listed indicators. Land degradation indicator Description Studies Land Cover Land cover data provides fundamental baseline information for land degradation assessments and monitoring.

Poor crop yield may serve to indicate poor state of the soils largely due to soil degradation in the given area Sonneveld et al. This is an NDVI data set that has been corrected for calibration, view geometry, volcanic aerosols and other effects not related to vegetation change. The current release of this data set, added to the Data Library on 06 August , contains NDVIg data on a global geographic projection evenly spaced in latitude and longitude for the period July to December For each grid point there are two values per month, the maximum NDVI value for the first fifteen days of the month, and the maximum value for the remainder of the month.

It is carefully assembled from different AVHRR sensors and accounting for various deleterious effects such as calibration loss, volcanic eruptions, orbital drift etc. The latest version of this data set spans the period The data and images have a 4 km spatial and 7-day composite temporal resolution. In the first phase 3 consistent global Land Cover LC products corresponding to the , and periods, climatological 7-day time series representing seasonal dynamics of the land surface, Medium Resolution Imaging Spectrometer MERIS Surface Reflectance SR time series which served as input for generating the global land over maps.

The system provides well curated biomass plot data in a unified format, which is aggregated from tree level data consistently across different networks. Reference and imagery are median observations from a set of quality assessment-passed growing season observations. The data serves as a valuable resource for several applications including land use land cover change, forestry, geology, agriculture, regional planning and education.

Level-1 data products are used to create higher-level science data such as surface temperature, surface water, burned area and snow covered area. Landsat Level-2 and Level-3 Science Products contain higher-level data to allow scientists to better document changes to Earth's terrestrial environment.

Landsat Analysis Ready Data ARD are processed to highest scientific standards, and placed in a tile-based structure to support time-series analysis.

Landsat Collections ensures that the data in the Landsat Level-1 archive are consistent in processing and data quality to support time-series analyses and data stacking. The Global Land Service systematically produces a series of qualified bio-geophysical products on the status and evolution of the land surface, at global scale and at mid to low spatial resolution, complemented by the constitution of long term time series.

The products are used to monitor the vegetation, the water cycle, the energy budget and the terrestrial cryosphere. The resulting raster database consists of rows and columns, which are linked to harmonized soil property data.

The use of a standardized structure allows for the linkage of the attribute data with the raster map to display or query the composition in terms of soil units and the characterization of selected soil parameters organic Carbon, pH, water storage capacity, soil depth, cation exchange capacity of the soil and the clay fraction, total exchangeable nutrients, lime and gypsum contents, sodium exchange percentage, salinity, textural class and granulometry.

The information in the table can be linked to the units of the map. SOTER databases provide data on key soil and terrain properties that are relevant input to agro-environmental applications such as food projection studies, climate studies carbon sequestration , land evaluation or hydrological catchment modelling. This mission helps scientists understand the links between Earth's water, energy and carbon cycles; reduce uncertainties in predicting weather and climate; and enhance our ability to monitor and predict natural hazards such as floods and droughts.

These data are modeled to represent estimated thicknesses by landform type for the geological present. These data were developed to support USDA-based curve-number runoff modeling at regional and continental scales.

Classification of HSGs was derived from soil texture classes and depth to bedrock provided by the Food and Agriculture Organization soilGridsm system. The total soil loss has been estimated to 35 Pg yr-1 of soil eroded in The estimates are lower compared to past studies in , On average, human populations in drylands have a lower quality of life than people in other areas. Worldwide, approximately half of the people living below the poverty line live in drylands and their societies are particularly vulnerable as a result of dryland ecosystem conditions and poverty.

Addressing desertification would therefore contribute to the eradication of extreme poverty and hunger. The creation of a "culture of prevention" can go a long way toward protecting drylands when desertification is just beginning and even when it is ongoing.

It has been shown that dryland populations , building on long-term experience and active innovation, can stay ahead of desertification by improving agricultural and grazing practices in a sustainable way. Rehabilitation and restoration approaches can help restore ecosystem services that have been lost due to desertification.

Restoration aims to reestablish a previous ecosystem state and all its functions and services , while rehabilitation seeks to repair specific parts of the systems, in order to regain ecosystem productivity. Effective restoration and rehabilitation of desertified drylands require a combination of policies and technologies and the close involvement of local communities. Examples of actions to restore and rehabilitate ecosystems include:.

Policies that create incentives for rehabilitation include capacity building , capital investment, and supportive institutions. The success of rehabilitation practices depends on the availability of human resources, sufficient funds and infrastructures, as well as on the degree of dependence on external technologies and cultural perceptions. The consequences of these include soil erosion, the loss of soil nutrients, changes to the amount of salt in the soil, and disruptions to the carbon, nitrogen and water cycles — collectively known as land degradation.

Land degradation leads to the reduction or loss of the biological or economic productivity and complexity of land. In drylands, land degradation is known as desertification. Biodiversity Drylands support an impressive array of biodiversity. This includes wild endemic species — such as the Saiga Antelope in the Asian steppe and American bison in the North American grasslands that do not occur anywhere else on earth — and cultivated plants and livestock varieties known as agrobiodiversity.

Biodiversity in drylands also includes organisms which live in the soil, such as bacteria, fungi and insects — known as soil biodiversity — which are uniquely adapted to the conditions. Soil biodiversity comprises the largest variety of species in drylands — determining carbon, nitrogen and water cycles and thereby, the productivity and resilience of land.

The loss of biodiversity in drylands is one of the major causes and outcomes of land degradation. Food and water provision Low precipitation and prolonged dry seasons in drylands can lead to water scarcity, and limit agricultural productivity and output. Drylands biodiversity maintains soil fertility and moisture to ensure agricultural growth, and reduces the risk of drought and other environmental hazards.

For example, vegetation is decomposed in the stomachs of large herbivores in the drylands, after which the dung is transformed into nutrients by bacteria in the soil, which are absorbed by plants. Bacteria and other microbes also break down plants and animals into decomposing residues — soil organic matter, which helps the soil easily absorb rainwater and retain moisture.

Each gram of organic matter can increase soil moisture by grams, and each millimetre of additional infiltration of water into the soil represents one million additional litres of water per square kilometre. Poor crop and soil management, and habitat destruction undermine the ability of drylands biodiversity to perform nutrient recycling, and water storage and filtration services.

This represents a significant contribution to man-made greenhouse gas emissions. Increasing the quantity of carbon contained in soil, for example through agriculture and pasture management practices which increase soil organic matter, can reduce the annual increase in carbon dioxide in the atmosphere. It is estimated that improved livestock rangeland management could potentially sequester a further 1,, million metric tons of carbon dioxide by