Investigating syndromes of agricultural land degradation through past trajectories and future scenarios

Land degradation (LD) is regarded as one of the most important processes leading to environmental degradation. LD specifically refers to a reduction in terms of economic productivity and capacity of providing ecosystem services by cropland, rangeland, and woodlands. Archetypal patterns or "syndromes" of LD can then be evaluated in the past, and scenarios developed for the future, informing sustainable land management strategies. Land cover is the visible result of the interactions between natural and socio-economic systems. It often reveals the occurrence of LD, either because it bears a direct effect on the processes or because it is associated with unsustainable land uses. Land use and land cover (LULC) are therefore essential for interpreting change trajectories associated with LD and deriving prediction rules. Whenever available, LULC data providing comparable classifications as well as the needed spatial resolution and time coverage can be derived from existing thematic cartography. In alternative, a procedure for the semi-automatic generation of LULC data from archive Landsat (7,5) satellite imagery since the mid-eighties, is under development. The procedure combines pixel and object oriented classifications and makes use of multi resolution segmentation for down dating and updating procedures. Past trajectories in LULC are analysed at regional level together with trends in other relevant drivers, for investigating associated land degradation syndromes (e.g. urban sprawl and soil sealing, aridity and climatic aggressiveness, water and soil erosion, agricultural pressure) through quantitative indicators of vulnerability (e.g. ESAI-Medalus, ESI LADA-FAO) and more "narrative" and participative interpretations (e.g. "story lines"). Climatic forecasts, population projections, as well as land use modelling are also used for developing LD scenarios.In the context of the research project AGROSCENARI (Scenarios of agriculture adaptation to climate change) promoted by the Italian Ministry of Agriculture, the research line "Land Degradation Processes and Climate Change" intends to investigate trajectories and syndromes as well as scenarios of land degradation, especially in face of climate change, in a number of test areas in the country. Methodological issues and preliminary results are discussed in this paper, with particular reference to the case of the Emilia-Romagna Region and to degradation processes associated to urban growth and sprawl.

Land degradation (LD) is among the major environmental and anthropogenic problems driven by land use-land cover (LULC) and climate change worldwide. For example, poor LULC practises such as deforestation, livestock overstocking, overgrazing and arable land use intensification on steep slopes disturbs the soil structure leaving the land susceptible to water erosion, a type of physical land degradation. Land degradation related problems exist in Sub-Saharan African countries such as Botswana which is semi-arid in nature. LULC and LD linkage information is still missing in many semi-arid regions worldwide.Mapping seasonal LULC is therefore very important in understanding LULC and LD linkages. This study assesses the impact of seasonal LULC variation on LD utilizing Remote Sensing (RS) techniques for Palapye region in Central District, Botswana. LULC classes for the dry and rainy seasons were classified using LANDSAT 8 images at Level I according to the Food and Agriculture Organization (FAO) International Organization of Standardization (ISO) code 19144. Level I consists of 10 LULC classes. The seasonal variations in LULC are further related to LD susceptibility in the semi-arid context. The results suggest that about 985 km² (22%) of the study area is susceptible to LD by water, major LULC types affected include: cropland, paved/rocky material, bare land, built-up area, mining area, and water body. Land degradation by water susceptibility due to seasonal land use-land cover variations is highest in the east of the study area where there is high cropland to bare land conversion.

IntroductionSoil erosion and land degradation pose significant threats to sustainable resource management in the Beshilo Watershed, Northeastern Ethiopia. These challenges are driven by steep slopes, unsustainable agricultural practices, and deteriorating soil health, necessitating a comprehensive assessment to inform effective mitigation strategies.Methods This study integrates geospatial analysis and field surveys to evaluate land degradation severity and identify soil erosion hotspots. The Revised Universal Soil Loss Equation (RUSLE) model, land use/land cover (LULC) analysis, and normalized difference vegetation index (NDVI) mapping are employed alongside FAO soil data, including soil organic matter (SOM), texture, and permeability assessments. GPS-documented inventories of active landslides and gullies further enhance the analysis.ResultsThe findings reveal alarming soil erosion rates, with RUSLE values ranging from 0 to 1,288 t/ha/year, an average annual loss of 68.3 t/ha/year, and a total soil loss of 664,333 tonnes‐far exceeding Ethiopia’s tolerable limits of 12‐18 t/ha/year. Approximately 38.5% of the watershed is categorized as high or severe erosion risk. GIS analysis reports a standard deviation of 100.06 for soil loss, highlighting spatial variability. LULC analysis shows that 73.4% of the area is under cultivation, while forest cover has declined to 7%. NDVI values range from ‐0.24 to 0.58, indicating severe vegetation degradation. Soil assessments report low SOM levels (1‐3%), weak soil structure ratings (1‐4), and a predominance of sandy loam texture (78%), all contributing to heightened erosion vulnerability.Discussion and ConclusionThe results highlight the urgent need for targeted Sustainable Land Management (SLM) interventions to mitigate soil erosion and rehabilitate degraded lands. Recommended measures include terracing, agroforestry, vegetative buffer strips, and integrated soil and water conservation strategies. These findings provide essential data to support evidence-based policymaking and the implementation of effective land management practices in erosion-prone regions.

Abstract. Land degradation (LD) is among the major environmental and anthropogenic problems driven by land use-land cover (LULC) and climate change worldwide. For example, poor LULC practises such as deforestation, livestock overstocking, overgrazing and arable land use intensification on steep slopes disturbs the soil structure leaving the land susceptible to water erosion, a type of physical land degradation. Land degradation related problems exist in Sub-Saharan African countries such as Botswana which is semi-arid in nature. LULC and LD linkage information is still missing in many semi-arid regions worldwide.Mapping seasonal LULC is therefore very important in understanding LULC and LD linkages. This study assesses the impact of seasonal LULC variation on LD utilizing Remote Sensing (RS) techniques for Palapye region in Central District, Botswana. LULC classes for the dry and rainy seasons were classified using LANDSAT 8 images at Level I according to the Food and Agriculture Organization (FAO) International Organization of Standardization (ISO) code 19144. Level I consists of 10 LULC classes. The seasonal variations in LULC are further related to LD susceptibility in the semi-arid context. The results suggest that about 985 km² (22%) of the study area is susceptible to LD by water, major LULC types affected include: cropland, paved/rocky material, bare land, built-up area, mining area, and water body. Land degradation by water susceptibility due to seasonal land use-land cover variations is highest in the east of the study area where there is high cropland to bare land conversion.

Land is a key environment and natural resource assets in Agriculture. It is also the case that the viability of arable land has a direct relationship with productivity. Land degradation caused by soil erosion is a major threat to the sustainability of agriculture. Soil erosion is one of the main forms of land degradation in Ghana, a problem that has been studied and researched by numerous scholars both local and abroad. Since 2006, the agricultural sector’s contribution to Gross Domestic Product has declined, possibly because of the negative effects of land degradation i.e. soil erosion challenges among others. The paper assesses the cost of land or soil degradation in the Agricultural Sector and its effect on the economy of Ghana with focus on the on-site effects of soil erosion on agricultural productivity. The study draws on the productivity loss and nutrient replacement cost approaches in estimating the cost of soil degradation in the agricultural sector. The results show the Northern region as the most prone to soil degradation, and that the real cost of agricultural soil degradation as a percentage of real Gross Domestic Product is approximately 2.5% on average, for a 4 year period from 2006 to 2012, which is equivalent to approximately GH¢ 964.92 million in monetary terms. The Sustainable Land Management (SLM) practices would be key in efforts to mitigate land degradation; enhancing agricultural biodiversity, and reducing poverty. SLM should thus be implemented particularly in the northern part of the country.

Influence of biophysical aspects on the performance of sustainable land management measures in the Usambara highlands of Tanzania

Optimizing soil and water management in dryland farming systems in Cabo Verde

Land degradation is a primary form of global environmental deterioration. Soil erosion and land desertification are common land degradation processes in many regions. In this research, we take the Zhuoshui River basin in central Taiwan as the study area, and investigate the environmental sensitivity of different land use/land cover to land degradation subjected to historical and future climate scenarios. In order to understand the quality of land resources in the study area, we used the evaluating framework of the Mediterranean Desertification and Land Use (MEADALUS) model with revisions according to the localized mountainous characteristics in central Taiwan, and calculated the Environmentally Sensitive Areas Index (ESAI) of the study area. The ESAI is comprised of five indicators, which include climate, soil, vegetation, management, and landslide indicators. For the climate index, observed data from 2001 to 2020 of weather factors were used in the historical scenarios. On the other hand, data of weather factors generated by MIRCO5 GCM considering RCP2.6 and RCP8.5 scenarios in near-term and long-term time scales were used for the climate indicator in the future scenarios. The results depict the spatial variation of environmental sensitivity to land degradation in the Zhuoshui River basin using numerical values ranging from 1 to 2, where higher values correspond to more severe degradation. It is evident that the upper reaches of the Zhuoshui River exhibit lower degrees of land degradation due to dense vegetation, higher elevations, and limited human presence. In contrast, the downstream areas show a higher trend of land degradation, with the wet season exhibiting lower degradation trends compared to the dry season. Furthermore, there is a slight upward trend in land degradation since 2015, primarily attributed to climate indicators, as soil and vegetation indicators, as well as anthropogenic management indicators, show no significant changes. The land degradation index shows relatively subtle differences between future scenarios and historical scenarios, with land degradation index variations ranging from -13% to 22%. Negative values in the degradation index differences indicate an improvement in the degree of degradation, while positive differences denote an exacerbation of land degradation. According to the land use distribution in the Zhuoshui River basin, the land degradation trends for forests and national parks show relatively consistent variations between the dry and wet seasons. However, in the middle and lower reaches of the basin, apart from the RCP85 scenario for the long-term period, the other three scenarios exhibit higher differences in land degradation index changes for agricultural and urban areas compared to historical values. The research provides a reference for preventing continued land degradation and conserving terrestrial ecosystems and biodiversity in the study area.

To deal with the increasingly severe land degradation in the downstream of the Heihe River Basin(HRB) in northwest China, an Ecological Water Diversion Project(EDWP) was implemented since 2000. A comprehensive analysis of the effects associated with the project on land degradation is necessary. According to the concept of Land Degradation Neutrality (LDN), multi-sensor data has been used to extract information on Land Use/Land Cover (LULC), aeolian desertification, and vegetation dynamics, which were chosen as monitoring indices to reveal the process of land degradation in the HRB. Then, these results were combined with meteorological data, socio-economic statistics, and hydrological data to discuss the main driving factors influencing the land degradation process to evaluate the effects of the EWDP on land degradation in the HRB. The results showed that the process of land degradation in the HRB could be divided into two stages, in which the degradation trend was dominant from 1990 to 2000, and the rehabilitation trend was dominant from 2000 to 2015. Although both climate variation and human activities have been favorable to land degradation development in the HRB, climate factors have no significant influence on land degradation in the midstream and downstream in the HRB. The decrease of available water resources is the dominant driving factor of a series of ecological environment problems in the downstream of the HRB, and the land degradation process of the HRB has been stopped and reversed mainly attributed to the EWDP. The EWDP facilitated the recovery of the deteriorated ecosystem by improving the efficiency of surface water resources reallocation in the downstream. Still, the EWDP indirectly led to the sink of the groundwater table in the midstream with resulting in local vegetation degradation.

This study was conducted with the objective of determining the returns to sustainable land management (SLM) at the national level in Bhutan. The study first uses satellite data on land change (Landsat) to examine land use change in 1990–2010 and its impact on sediment loading in hydroelectric power plants. The study then uses the Soil and Water Assessment Tool (SWAT) model to analyze the impact of land use change and land management on sediment loading. The results from the land use change and SWAT analyses are used to assess the economic benefits of SLM. We estimate the benefits and costs of SLM practices and compare them with the land-degrading practices that are most prevalent in Bhutan—that is, business as usual. An analysis of the drivers of adoption of SLM practices is also done to draw conclusions about strategies that Bhutan could use to enhance adoption of SLM practices. The land cover change results show that the vast majority of forested areas remained as such between 1994 and 2010. SWAT results show that with long-term SLM practices such as contouring, increased forested cover and density, terracing, and other SLM practices, soil erosion from forested area could be reduced by 50 %. Analysis of returns to SLM practices showed that citrus orchards are the most profitable enterprises in 13 of the 20 districts (dzongkhag), but they require farmers to wait for at least six years before the first harvest. Improved pasture management is the second most profitable enterprise—underscoring the potential role it can play to meet the growing demand for livestock products as household incomes increase. Returns to community forest management are low but profitable at a 10 % discount rate. Considering the drivers of SLM adoption, our research shows an inverse relationship between returns to land management and their corresponding adoption rates. The factors that increase adoption of SLM were land security, access to extension services, and roads. In summary, Bhutan’s policies and its cultural and historical background have set the country on the path to becoming a global green growth success story. Results of this study vindicate the country’s efforts to invest in sustainable land and forest management and highlight the additional policies and strategies that will enhance achievement of Bhutan’s SLM objectives.

The Assessment of Global Trends in Land Degradation.- Status and Trends in Land Degradation in Africa.- Status and Trends in Land Degradation in Asia.- Trends in Land Degradation in Latin America and the Caribbean, the Role of Climate Change.- Trends in Land Degradation in Europe.- Climate and Land Degradation - an Overview.- Climate, Extreme Events and Land Degradation.- Effects of Some Meteorological Parameters on Land Degradation in Tanzania.- Rainfall and Land Degradation.- Frequency of Wet and Dry Spells in Tanzania.- Climate Variability, Climate Change and Land Degradation.- Fire Weather and Land Degradation.- Importance of Drought Information in Monitoring and Assessing Land Degradation.- The Role of Land Degradation in the Agriculture and Environment Nexus.- Using Weather and Climate Information for Landslide Prevention and Mitigation.- Drought Hazard and Land Management in the Drylands of Southern Africa.- Climate Monitoring in the Southern Africa Development Community.- Carbon Sequestration and Land Degradation.- Sustainable Land Management Through Soil Organic Carbon Management and Sequestration - The GEFSOC Modelling System.- Seasonal Variation of Carbon Dioxide, Rainfall, NDVI and it's Association to Land Degradation in Tanzania.- Land Degradation Control in Northern Africa.- Challenges and Trade-Offs in Environmental and Financial Approaches of the Afforestation of Degraded Lands.- The EU-Funded Medcoastland Thematic Network and its Findings in Combating Land Degradation in the Mediterranean Region.- Managing Land Use, Protecting Land and Mitigating Land Degradation: Tanzania Case Study.- Implementation of Initiatives for Addressing Climate Change and Land Degradation: A Look at the Philippine Context.- Successful Grassland Regeneration in a Severely Degraded Catchment: a Whole of Government Approach in North West Australia.- Land Degradation Management in Southern Africa.- Successful Experiences of Sustainable Land Use in Hyperarid, Arid and Semiarid Zones from Peru.- Role of Organic Agriculture in Preventing and Reversing Land Degradation.- Using Better Climate Prediction in the Implementation of National Action Programmes - (Eastern) Europe.- Improving NAP Implementation through Effective Use of Early Warning: Experiences in the IGAD Sub-Region.- Role of Drought Monitoring and Management in NAP Implementation.- Climate and National Action Programs in Latin America.- Conclusions and Recommendations.- Workshop Statement.

Linking trajectories of land change, land degradation processes and ecosystem services

Land degradation and desertification (LDD) and climate change are having increased effects in the Near East and North Africa (NENA) impacting the livelihoods of about 410 million people. Agriculture is a vital sector, contributing on average 14% to the Gross Domestic Product (GDP) (excluding oil producing countries) and providing jobs and incomes for 38% of the region’s economically active population. Nevertheless, most NENA countries import at least 50% of the calories they consume. Furthermore, it is estimated that the total area that is desertified or is vulnerable to desertification cover 9.84 million km2 or about 86.7% of the total NENA region. Soil erosion by water, wind, and sand and dust storms (SDS) cause losses of about USD 13 billion of GDP each year. To confront these hardships, the region must endorse proper land use planning, prioritization of target areas for restoration and adoption of sustainable land and water management (SLWM) to reverse the situation. This paper analyses the inter-linkages between LDD, resource base management and food security under different scenarios and offers mitigation and remediation options. These include knowledge management and sharing; establishment of a regional platform to facilitate dialogue; public and private investment opportunities; provision of tools to scale-out sustainable land and water management options; and creation of a conducive enabling environment supported by policies and strategies. The paper provides policy and decision-makers with priority actions and options to enhance productivity, and combat land degradation to improve food security in the region.

Agroforestry‐based sustainable land management (SLM) interventions provide opportunities for tackling land degradation and its associated socio‐economic issues. Agroforestry is not a guaranteed SLM fix as every agroforestry practice is not automatically relevant to each context. It is critical to identify key considerations for ensuring a good fit between agroforestry and the receiving environment. This study identifies and analyses key factors for assessing the context‐specific suitability of an agroforestry practice for SLM using a case‐study of homegarden agroforestry in a degraded catchment. An analysis of biophysical and socio‐economic characteristics of the catchment covering land degradation, SLM aspirations of residents, agriculture and agroforestry activities was conducted through literature review, field observations, GIS and remote sensing, stakeholder engagement and a questionnaire survey. Considerations in agroforestry practice assessment for SLM include agricultural and SLM objectives, which at our study site were increased crop production and arresting soil erosion. Availability of requisite resources, namely land, water and fencing; stakeholder interest in the tree and/or crop planting, species of interest and suitability of the species for the biophysical conditions should also be assessed. We propose a framework for systematically working through the relevant factors and assessing the suitability of an agroforestry practice for SLM intervention in a specific context. Based on the framework, homegarden agroforestry is an appropriate SLM intervention as it could meet stakeholders' SLM and agricultural objectives. Identification and systematic assessment of relevant factors are critical for ensuring the acceptability of agroforestry practice in a locality and the sustainability of associated SLM interventions.

Preface Global Pioneers in Soil Conservation: Common Elements and Lessons Learned