Using remotely sensed imagery to monitor savanna rangeland deterioration through woody plant proliferation: a case study from communal and biodiversity conservation rangeland sites in Mokopane, South Africa

Healthy rangelands are of economic and biodiversity conservation importance in the savannas of northern South Africa. The proliferation of woody plant species on the rangelands, known as bush encroachment, constitutes a degradation of rangeland quality, given the non-palatability of the encroaching species. Though the causes are not fully understood, heavy grazing and fire suppression are thought to be primary causes of bush encroachment. This study utilised multitemporal (1994, 2000 and 2008) SPOT images of two rangeland sites in Mokopane, South Africa in monitoring and assessing bush encroachment. The study sites were a fenced biodiversity conservation rangeland with game species in which fire is suppressed and an open access communal rangeland grazed by livestock. Field plot-derived encroachment categories of heavy encroachment, moderate encroachment, low encroachment and non-encroached were used in hybrid classification of the images, following radiometric normalisation and geometric registration. GIS overlay analysis using the non-encroached category enabled the quantification and mapping of change in the preferable open grass rangeland typifying savannas. The biodiversity conservation area was undergoing a trend of reduction in open grass rangeland, whereas the communal rangelands were getting more opened up by livestock trampling. Rangeland management practices of fire utilisation, stocking levels and stock concentration account for the differing trends. Lightly grazed and heavily grazed wild game-utilised rangelands under a fire suppression rangeland management regime had bush encroachment rates of approximately 34% and 56%, respectively, in 6 years. Multitemporal remote sensing proved to be useful for monitoring bush encroachment as indicator of state of savanna rangelands.     

Drought Hazard and Desertification Management in the Drylands of Southern Africa

Droughts have been occurring persistently in southern African dryland regions for over a century. The impacts of droughts on people, their domesticated animals, wildlife, rangelands and cropped lands have been shown to be astronomical. If left alone the rangelands often recover after the calamity, however human occupation has led to irreversible damage. Even though some communities have evolved viable and sustainable coping mechanisms, recent times have seen weakened coping strategies leading to loss of life in most of the 10 countries in southern Africa. While land degradation has many inter-related causes and effects, drought-related effects have proven most difficult to manage and/or overcome. Drought-related land degradation or desertification poses a huge threat to sustainable land and resource management in the region. The paper examines appropriate drought mitigating initiatives, linking them to land tenure and land management practices. Numerous interventions targeted at reducing poverty and improvement in resource management have failed to achieve desired effects due to rigidity and imposition, and failure of the external interveners to recognise and incorporate indigenous peoples’ preferences and coping strategies. Non-governmental organisations and authorities’ willingness to institute drought and desertification combating measures are reviewed, highlighting the role that community action plays in reducing adverse effects in the region. Linkages to trade patterns that perpetuate poverty and unwise use of resources are discussed. Adopting ‘people centred’ mitigating measures is emphasised. Success rests with both the people in the ‘south’ and those in the ‘north’. What is required is an informed global action.     

Native Seed Collection and Use in Arid Land Reclamation: A Low-Tech Approach

Loss of vegetation production in arid lands has been difficult to remediate and has signifi- cant economic impacts on human populations. Restoration efforts based on non-local materials and large-scale mechanization have not been capable of efficiently reversing the trend of environmental degradation. The use of traditional knowledge and simplified methods of seed harvesting, storing, marketing and soil preparation have proven that regeneration of native species and efficient land reclamation is possible in areas that have traditionally been considered degraded beyond redemption. This paper describes a method of land reclamation that combines tradition and simple mechanics that can be applied in all arid areas that face desertification. Because the work builds on cultural practices long used in non-industrialized societies, it is particularly adapted to rural areas. The methods described have the potential to open new low-tech economic opportunities to all segments of local non-urban populations while combating desertification and creating a more ecologically sound environment.     

A Decision Support System Approach for Rivers Monitoring and Sustainable Management

This paper presents a Decision Support System (DSS) approach developed in the context of the Copernicus project entitled System for Water Monitoring and Sustainable Management based on Ground Stations and Satellite Images (WATERMAN). The main objective of WATERMAN is the monitoring and management of the Strymon River in the Southern Balkans. The specific DSS integrates the main components of WATERMAN and helps the decision maker to monitor the Strymon region; to control and forecast the quantity and quality of the river water; as well as to make objective decisions about the state of the water based on data provided by radio computers, earth stations and satellite images processed by mathematical and statistical models and Geographical Information Systems (GIS).     

South Africa's arid and semiarid rangelands: Why are they changing and can they be restored?

Since the mid-19th century settled livestock ranching has been the major form of land use in South Africa, occupying 68% of the land surface. Decreases in livestock densities and ranch numbers during the past century imply that carrying capacities for domestic herbivores are falling. Differences in carbon isotope signals with soil depth and abrupt shifts in dominant plant species across ranch boundaries reveal that southern African rangelands are changing. Case studies suggest ways to control altered grassland composition, bush encroachment in arid savanna, and dominance by toxic and halophytic shrubs in arid shrublands. But climatic and biological factors constrain rates of passive recovery, and guidelines for active restoration are poor and techniques costly. Moreover, conservation of remaining good rangeland is seldom enforced, and economic considerations usually outweight the land user's desire to sustain diversity and productivity.     

A Knowledge-Based Approach to the Assessment of Watershed Condition

The Ecosystem Management Decision Support (EMDS) system is an application framework for knowledge-based decision support of ecological assessments. EMDS integrates geographic information system and knowledge base system technologies to provide an analytical tool for environmental assessment and monitoring. The basic objective of EMDS is to improve the quality and completeness of environmental assessments and the efficiency with which they are performed. The USDA Forest Service and the U.S. Environmental Protection Agency have cooperatively developed an EMDS knowledge base for watershed condition assessment. Specifically, this knowledge base evaluates watershed processes, patterns, general effects of human activity, and fisheries habitat suitability. Such assessments are based on spatially explicit input data concerning current conditions and reference conditions which are subsequently interpreted by user-defined "fuzzy" membership functions. In this paper we describe basic components of our knowledge base for assessing watershed condition and illustrate its application within northern Idaho and northwestern Montana.     

Community Based Interventions as a Strategy to Combat Desertification in the Arid and Semi-Arid Rangelands of Kajiado District, Kenya

Vegetation degradation, especially the disappearance of woody vegetation and a diminished grass cover, has aroused the concern of the Maasai community (semi-nomadic pastoralists) of Kajiado District, Kenya. The district is one of Kenya’s arid and semi-arid districts. Over recent years, they have observed their land resources deteriorate due to the desertification process caused by the land use practices of man. They have identified indicators of desertification such as increase of bare lands, which have been invaded by previously unknown grasses and weeds that are of no economic value, and also the disappearance of some useful plant species. It is due to the above concerns that a group of 30 farmers have been very keen to participate in on-farm research to strategize on ways to halt and even reverse the desertification process. The participatory research has identified useful trees that the farmers have been planting around homesteads, as woodlots on their farms to provide woodfuel, shade, and to act as windbreaks. They have also identified species for planting as live fences instead of using thorny tree branches as fencing material, which contributes further to the desertification process. Due to the termite menace on young tree seedlings, the farmers use indigenous knowledge to prepare concoctions using locally available materials, which they apply to planting holes and on seedlings. During awareness campaigns, the farmer research group highlights the need to conserve vegetation resources and also expounds on the concept of planting two trees after one is felled.     

10th anniversary review: addressing land degradation and climate change in dryland agroecosystems through sustainable land management

Sustainable land management (SLM) is proposed as a unifying theme for current global efforts on combating desertification, climate change and loss of biodiversity in drylands. A focus on SLM will achieve the multiple goals of the three UN Conventions (UNCCD, UNFCCC and UNCBD) and in particular will address the roots causes of poverty and vulnerability to climate change rather than a current focus on adapting to climate change. The interlinkages between land degradation, climate change and loss of biodiversity are outlined together with a proposed set of interventions to achieve multiple goals. It is argued that improved land productivity is a viable goal to reduce poverty in drylands provided it is linked to payments for environmental services and better crop and weather insurances and coupled with alternative livelihoods that are not primarily dependent on land productivity. Obstacles to the achievement of SLM are discussed and the steps necessary to overcome them are presented. It is suggested that promoting SLM would be a better focus for the UNCCD than combating desertification.     

Monitoring and analysis of natural vegetation in a Special Protected Area of Mountain Antichasia—Meteora, central Greece

Natural ecosystems are renewable resources with special environmental, social, and economical attributes and characteristics. The increasing need of human beings for a better environment results in the use of new technologies that offer many advantages in detecting changes in the ecosystems. Remote sensing tools, technology, and the spatial analysis of the Geographic Information System were used in determining any changes in this study which attempts to classify land cover over a 10-year period. The study area is in Thessaly, central Greece, and has been classified as a Special Protection Area, because of its important wild fauna. The results have shown that current technologies can be used for modeling environmental parameters which improve our knowledge of the attributes, characteristics, situation, trends, and changes of natural ecosystems. The changes over time that have been observed result from the development of the vegetation or to anthropogenic and socioeconomic reasons. Rational range management will be a very comprehensive tool for farmers. This action will have a positive impact on flora in the rangelands. The core strategy is to combine forest, pasture, and livestock so that each component produces usable products.     

Connecting Research to Combating Desertification

With and without the encouragement of the United Nations Convention to Combat Desertification and its Committee on Science and Technology, scientific research has been undertaken throughout the drylands with the expectation of contributing to combating desertification. Little of this research has been applied in developing countries for its identified purpose. The main reason for this is the limited translation of scientific research into an accessible format for application by development agencies or rural communities.     

浅析新疆环境应急管理与决策支持系统

针对在处理、处置突发性环境污染事故中存在的突出问题，阐述了利用GIS等技术在设计开发新疆环境应急管理与决策支持系统的总体设计理念，对其总体应用框架、主要应用功能等进行了分析。该系统设计既满足应急管理需要又考虑了污染源日常管理的工作需要，将在实际应用中发挥重要作用。     

Dynamics of aeolian desertification and its driving forces in the Horqin Sandy Land,Northern China

Aeolian desertification is one of the most serious environmental and socioeconomic problems in arid, semi-arid, and dry subhumid zones. Understanding desertification processes and causes is important to provide reasonable and effective control measures for preventing desertification. With satellite remote sensing images as data source to assess the temporal and spatial dynamics of desertification from 1975 to 2010 in the Horqin Sandy Land, dynamic changes of aeolian desertification were detected using the human–machine interactive interpretation method. The driving factors of local desertification were analyzed based on natural and socioeconomic data. The results show that aeolian desertified land in the study area covered 30,199 km² in 2010, accounting for 24.1 % of the study area. The total area of aeolian desertified land obviously expanded from 30,884 km² in 1975 to 32,071 km² in 1990, and gradually decreased to 30,199 km² in 2010; aeolian desertified land represented an increasing trend firstly and then decreased. During the past 35 years, the gravity centers of desertified lands that are classified as extremely severe and severe generally migrated to the northeast, whereas those that are moderate and slight migrated to the northwest. The migration distance of severely desertified land was the largest, which indicated the southern desertified lands were improved during the last few decades. In addition, the climatic variation in the past 35 years has been favorable to desertification in the Horqin Sandy Land. Aeolian desertified land rapidly expanded from 1975 to 1990 under the combined effects of climate changes and unreasonable human activities. After the 1990s, the main driving factors responsible for the decrease in desertification were positive human activities, such as the series of antidesertification and ecological restoration projects.     

A DSS for sustainable development and environmental protection of agricultural regions

This paper presents a decision support system (DSS) for sustainable development and environmental protection of agricultural regions developed in the framework of the Interreg-Archimed project entitled WaterMap (development and utilization of vulnerability maps for the monitoring and management of groundwater resources in the ARCHIMED areas). Its aim is to optimize the production plan of an agricultural region taking in account the available resources, the environmental parameters, and the vulnerability map of the region. The DSS is based on an optimization multicriteria model. The spatial integration of vulnerability maps in the DSS enables regional authorities to design policies for optimal agricultural development and groundwater protection from the agricultural land uses. The DSS can further be used to simulate different scenarios and policies by the local stakeholders due to changes on different social, economic, and environmental parameters. In this way, they can achieve alternative production plans and agricultural land uses as well as to estimate economic, social, and environmental impacts of different policies. The DSS is computerized and supported by a set of relational databases. The corresponding software has been developed in a Microsoft Windows XP platform, using Microsoft Visual Basic, Microsoft Access, and the LINDO library. For demonstration reasons, the paper includes an application of the DSS in a region of Northern Greece.     

A knowledge brokerage approach for assessing the impacts of the setting up young farmers policy measure in Greece

This study explores Knowledge Brokerage (KB) aspects of an ex-post Impact Assessment (IA) for the Rural Development Programme (RDP) measure of setting up young farmers, under the Common Agricultural Policy (CAP), at the regional level in Northern Greece. The measure supports the entry of young farmers in agriculture by moving land from older to younger farmers. The aim of the study was to test a set of KB tools for improving the interaction between researchers and policy makers. Our analysis mainly focused on a suite of IA Support Modules to guide practitioners, and on a technical tool kit, a web-based contextualisation platform, to support the IA of the specific test case. Offering a structured approach towards IA, both the Support Modules and LIAISE-KIT allow framing the context, organisation, scheduling and method selection in the light of KB objectives. The evaluation of how IA Support Modules influence the Science Policy Interface (SPI), in the case of the ex-post assessment, demonstrated the high relevance of KB activities for facilitating the interaction between researchers and regional policy makers. The assessment bridges the gap between knowledge producers developing scientific output to be applied in a specific context, and knowledge users, who want clear messages regarding the policy challenges they face. Other conclusions include the need for specific guidelines and training for knowledge users, especially with regard to the use of tools. According to our findings, a consequent application of KB activities is a crucial pre-condition for successfully implementing IAs in future RDP measures.     

玛纳斯河流域荒漠草地沙化遥感监测研究

以1989—2016年玛纳斯河流域TM/OLI遥感影像为数据源,利用混合像元分解技术,计算玛纳斯河流域草地总覆盖度和裸沙面积。在此基础上通过监测年与基期年的比较,计算草地覆盖度相对基期年的减少率和裸沙面积相对基期年的增加率两个监测指标,依据《天然草地退化、沙化、盐渍化的分级指标》(GB 19377—2003),对计算出的两个指标分别进行沙化等级评定和赋值,将两种评定结果相综合来监测草地沙化。结果表明,玛纳斯河流域近30年来荒漠草地沙漠化总体呈现先增加后降低的趋势。分析表明,玛纳斯河流域草地沙化是人为和自然因素双重作用的结果。     

Modeling Desertification Change in Minqin County,China

Monitoring environmental processes is becoming increasingly important wherever there is increasing population and economic development pressure placed on fragile environments. Remote sensing, digital image processing, and spatial analysis have proven to be useful technologies in both assessing and monitoring environmental change. In this study, they were used to assess desertification processes and change in Minqin County, China from 1988 to 1997. The results suggest that wind erosion was the dominant cause of desertification in more than half of the study area. Coupled with this were increases in salinization processes, affecting 33.62% of the land area in 1997. Overall, moderate desertification was found to be the dominant desertification grade (43.64% of total area), followed by extreme/severe desertification (26.15% of total area) in 1997. In addition, examination of landscape pattern changes indicated that desertification processes at the landscape level were becoming evident at increasing levels of fragmentation, complexity in shape, and isolation of patches. Major fluctuations in desertification type and grade were found at the fringes of oases, where an ongoing shift was taking place between cultivation, abandonment, and reclamation.     

A Landscape Approach for Detecting and Evaluating Change in a Semi-Arid Environment

Vegetation change in the American West has been a subject of concern throughout the twentieth century. Although many of the changes have been recorded qualitatively through the use of comparative photography and historical reports, little quantitative information has been available on the regional or watershed scale. It is currently possible to measure change over large areas and determine trends in ecological and hydrological condition using advanced space-based technologies. Specifically, this process is being tested in a community-based watershed in southeast Arizona and northeast Sonora, Mexico using a system of landscape pattern measurements derived from satellite remote sensing, spatial statistics, process modeling, and geographic information systems technology. These technologies provide the basis for developing landscape composition and pattern indicators as sensitive measures of large-scale environmental change and thus may provide an effective and economical method for evaluating watershed condition related to disturbance from human and natural stresses. The project utilizes the database from the North American Landscape Characterization (NALC) project which incorporates triplicate Landsat Multi-Spectral Scanner (MSS) imagery from the early 1970s, mid 1980s, and the 1990s. Landscape composition and pattern metrics have been generated from digital land cover maps derived from the NALC images and compared across a nearly 20-year period. Results about changes in land cover for the study period indicate that extensive, highly connected grassland and desertscrub areas are the most vulnerable ecosystems to fragmentation and actual loss due to encroachment of xerophytic mesquite woodland. In the study period, grasslands and desertscrub not only decreased in extent but also became more fragmented. That is, the number of grassland and desertscrub patches increased and their average patch sizes decreased. In stark contrast, the mesquite woodland patches increased in size, number, and connectivity. These changes have important impact for the hydrology of the region, since the energy and water balance characteristics for these cover types are significantly different. The process demonstrates a simple procedure to document changes and determine ecosystem vulnerabilities through the use of change detection and indicator development, especially in regard to traditional degradation processes that have occurred throughout the western rangelands involving changes of vegetative cover and acceleration of water and wind erosion.     

Desertification in Russia: Problems and solutions (an example in the Republic of Kalmykia-Khalmg Tangch)

During the second half of the 20th century Kalmykia has undergone severe desertification. Under Soviet rule, rangelands were increasingly devoted to animal production, and pastures were converted to cropland in a campaign to increase crops. Pastures were grazed two to three times their sustainable production, saiga populations and habitat greatly decreased, more than 17 million ha were subjected to wind erosion, 380,000 ha were transformed into moving sands, and 106,000 ha were ruined by secondary salinization and waterlogging. By the 1990s almost 80% of the Republic had undergone desertification, and 13% had been transformed into a true desert. In 1986 the General Scheme of Desertification Control was formulated. The scheme called for rotating pastures, reclaiming blown sand using silviculture, tilling overgrazed pastures and sowing fodder plants, and developing water supplies for pastures. In its early years the scheme has been successful. But the management of restored pastures usually reverts to the same farms responsible for the poor conditions, and there is great apprehension that degradation could reoccur. This case study concludes that the general cattle and agriculture development in Kalmykia is unviable for ecological and economic reasons, that Kalmykia should implement an adaptive policy oriented toward conservation and accommodating the interrelation and variability of land resources, that the desertification problem can be solved only by changing agrarian policy as a whole, and that a desertification control program must become an integral part of economic and social development of the Republic.     

Land desertification monitoring and assessment in Yulin of Northwest China using remote sensing and geographic information systems (GIS)

The objective of this study is to develop techniques for assessing and analysing land desertification in Yulin of Northwest China, as a typical monitoring region through the use of remotely sensed data and geographic information systems (GIS). The methodology included the use of Landsat TM data from 1987, 1996 and 2006, supplemented by aerial photos in 1960, topographic maps, field work and use of other existing data. From this, land cover, the Normalised Difference Vegetation Index (NDVI), farmland, woodland and grassland maps at 1:100,000 were prepared for land desertification monitoring in the area. In the study, all data was entered into a GIS using ILWIS software to perform land desertification monitoring. The results indicate that land desertification in the area has been developing rapidly during the past 40 years. Although land desertification has to some extent been controlled in the area by planting grasses and trees, the issue of land desertification is still serious. The study also demonstrates an example of why the integration of remote sensing with GIS is critical for the monitoring of environmental changes in arid and semi-arid regions, e.g. in land desertification monitoring in the Yulin pilot area. However, land desertification monitoring using remote sensing and GIS still needs to be continued and also refined for the purpose of long-term monitoring and the management of fragile ecosystems in the area.     

Towards sustainable settlement growth: A new multi-criteria assessment for implementing environmental targets into strategic urban planning

For nearly one decade, the German political and research-agenda has been to a large extent determined by the ongoing question of how to limit the expansion of settlement areas around cities in order to preserve natural resources, make settlement growth more sustainable and to strengthen the re-use of existing inner-urban areas (see a.o. Kötter et al. 2009a, 2010; Schetke et al. 2009, 2010b). What is already under discussion within the international literature are the recommendations of the German Council for Sustainability to quantitatively reduce the daily greenfield consumption from the current rate of over 100 ha per day to a rate of 30 ha per day in 2020 and to bring urban infill development up to a ratio of 3:1 with greenfield development (German Council for Sustainability, 2004).). This paper addresses the added value beyond those abstract political targets and presents an innovative, multi-criteria assessment (MCA) of greenfield and infill sites to evaluate their sustainability and resource efficiency. MCA development and its incorporation into a Decision Support System (DSS) were accomplished by utilising a stakeholder-driven approach. The resulting tool can be applied in preparing and revising land-use plans. The paper presents the concept and the development process of the MCA-DSS. Test runs with planners prove that the evaluation of potential housing sites using individually weighted environmental indicators helps to identify those strategies of housing development that accord most closely with sustainability goals. The tests further show that the development of greenfield sites generally exhibits less sustainability than that of infill sites.