Human migration,climate variability,and land degradation: hotspots of socio-ecological pressure in Ethiopia

Regional Environmental Change - In Ethiopia, human migration is known to be influenced by environmental change—and vice versa. Thus, degradation of environmental conditions can contribute to...     

Urbanization and its effects on land and water resources in Ijebuland,southwestern Nigeria

Environment, Development and Sustainability - The many widely reported significant environmental changes in sub-Saharan communities caused by population change and expansion of built-up areas have...     

Toward achieving a sustainable management: characterization of land use/land cover in Sokoto Rima floodplain,Nigeria

Land use change is the main driving force of global environmental change and is considered as very central to the ongoing debate on sustainable development. Even though large volume of literature materials is available of land use/land cover (LU/LC) change for many areas, very little is known of it in the floodplain of the Sokoto Rima River Basin of Nigeria despite the basin’s strategic importance. Thus, this study characterized the basin’s LU/LC and its change using computer-based digital classification of near-anniversary Landsat 5 TM imagery of November 23, 1998, and Landsat 8 OLI of December 2, 2013. The results of the digital classification were complimented with field-based observations on major observable characteristics of every LU/LC identified. Thirteen classes (forest area, dense grassland, grassy fallow, grazed open grassland, open cultivation, open grain fallow farmland, pepper cultivation, rice farmland, scrubland, sugarcane farmland, dry bare land, sand deposit and wetland/water) were characterized and the nature and extent of their changes assessed. 40 % of the basin’s uses is under cultivation, 22 % is under fallow, 27 % is either degraded or non-cultivable, while 11 % is forested. Change events include forest loss, increase in area cultivated, expansion of shrub/scrubland and pervasiveness of grazing. The changes were more pronounced in the upper than either the central and southern segments of the basin. In general LU/LC changes in the basin are reflection of increased human population pressure and effects of climate change. The LU/LC patterns and changes suggest underutilization and mismanagement of the floodplain which have impact on soil, hydrology and biodiversity with serious implication for livelihood and food security. The study recommends that interventions are needed to promote enhanced and sustainable management of land, water and vegetation resources in the basin, with particular emphasis on empowering the local land users to participate actively toward sustainable management of the floodplain.     

Potential impacts of climate change on agricultural land use suitability of the Hungarian counties

Central and Eastern European countries are a hotspot area when analyzing the impacts of climate change on agricultural and environmental sectors. This paper conducts a socio-economic evaluation of climate risks on crop production in Hungary, using panel data models. The region has a special location in the Carpathian basin, where the spatial distribution of precipitation varies highly from humid conditions in the western part to semiarid conditions in eastern Hungary. Under current conditions, crop systems are mainly rainfed, and water licences are massively underexploited. However, water stress projected by climate change scenarios could completely change this situation. In the near future (2021–2050), most of the crops examined could have better climatic conditions, while at the end of the century (2071–2100), lower yields are expected. Adaptation strategies must be based on an integrated evaluation which links economic and climatic aspects, and since the results show important differences in the case of individual systems, it is clear that the response has to be crop and region specific.     

Toward a ‘Sustainable’ land degradation? Vulnerability degree and component balance in a rapidly changing environment

Land degradation is a process negatively affecting environmental sustainability and requires permanent monitoring for understanding its nonlinear trajectories of change over time and space. Environmental sustainability is linked to a theoretical definition of dynamic balance among various components contributing to the ecosystem quality and functioning. The aim of this study is to develop a diachronic analysis (1960–2010) of the equilibrium/disequilibrium condition of key environmental factors (climate, soil, vegetation, land-use) influencing the vulnerability of land to degradation in a Mediterranean country experiencing processes of desertification at the local scale. Three indicators of components’ balance have been proposed and tested for spatial and temporal coherence. Land classified at high vulnerability and low component’s balance has been identified as a possible target for mitigation strategies against desertification; the surface area of this class increased rapidly during 1960–2010 and concentrated in high-intensity agricultural lowlands of northern Italy.     

Modelling land use change across elevation gradients in district Swat, Pakistan

District Swat is part of the high mountain Hindu-Kush Himalayan region of Pakistan. Documentation and analysis of land use change in this region is challenging due to very disparate accounts of the state of forest resources and limited accessible data. Such analysis is, however, important due to concerns over the degradation of forest land leading to deterioration of the protection of water catchments and exposure of highly erodible soils. Furthermore, the area is identified as hotspot for biodiversity loss. The aim of this paper is to identify geophysical and geographical factors related to land use change and model how these relationships vary across the district. For three selected zones across the elevation gradient of the district, we analyse land use change by studying land use maps for the years 1968, 1990 and 2007. In the high-altitude zone, the forest area decreased by 30.5 %, a third of which was caused by agricultural expansion. In the mid-elevation zone, agriculture expanded by 70.3 % and forests decreased by 49.7 %. In the lower altitudes, agriculture expansion was 129.9 % consuming 31.7 % of the forest area over the forty-year time period. Annual deforestation rates observed were 0.80, 1.28 and 1.86 % in high, mid and low altitudes, respectively. In the high-altitude ecosystems, accessibility (distance to nearest road and city) had no significant role in agriculture expansion; rather land use change appears significantly related to geophysical factors such as slope, aspect and altitude. In the low-elevation zone, accessibility was the factor showing the closest association with agriculture expansion and abandonment. The analysis illustrates that land use change processes vary quite considerably between different altitudinal and vegetation cover zones of the same district and that environmental constraints and stage of economic development provide important contextual information.     

Representing large-scale land acquisitions in land use change scenarios for the Lao PDR

Regional Environmental Change - Agricultural large-scale land acquisition (LSLA) is a process that is currently not captured by land change models. We present a novel land change modeling approach...     

Examination of land use/land cover changes,urban growth dynamics,and environmental sustainability in Chittagong city,Bangladesh

As in many other developing countries, cities in Bangladesh have witnessed rapid urbanization, resulting in increasing amounts of land being taken over and therefore land cover changing at a faster rate. Until now, however, few efforts have been made to document the impact of land use and land cover changes on the climate, environment, and ecosystem of the country because of a lack of geospatial data and time-series information. By using open source Landsat data integrated with GIS technologies and other ancillary data, this study attempts to classify land use and create land cover maps, enabling post-classification change detection analysis. By this method, we document the spatial and temporal trajectory of urban expansion in Chittagong, the second largest city in Bangladesh, over a 36-year period. The findings suggest that, over the study period, 56 % of the land cover has undergone change, mainly because of the expansion of built-up areas and other human activities. During the 36-year period, the built-up area around Chittagong city has expanded by 618 %, with an average annual rate of increase of 17.5 %. As a result of rapid urbanization, the vegetated hills near urban development areas face serious threats of further encroachment and degradation, given that 2178 ha of hills have already been intruded over the study period. Because urbanization processes in Bangladesh have traditionally been viewed as the result of population growth and economic development, very little work has been done to track the potential growth trajectory in a physical or spatial context. This study, therefore, will contribute to the current understanding of urban development in Bangladesh from a temporal and spatial point of view. Findings will be able to assist planners, stakeholders, and policy makers in appreciating the dynamism of urban growth and therefore will facilitate better planning for the future to minimize environmental impacts.     

Scenarios and story lines: drivers of land use change in southern Mexico

The study presents three scenarios of land use and cover change (LUCC), the most important factor for environmental degradation in southern Mexico. We developed story lines and quantitative projections for regional scenarios based on historic LUCC processes, environmental policies, socioeconomic drivers, stakeholder consultations and official planning documents to gain a better understanding of drivers of LUCC, and quantitative scenarios were modeled with DINAMICA-EGO. Regionally specific interactions between social and natural systems are recognized, and detrimental policies and policy options for landscape conservation and management for sustainability are acknowledged in a base line, variant and alternative scenario. Incongruent policies and ineffective ground implementation of conservation actions were identified as the critical underlying drivers of deforestation and forest degradation that could lead to a severe reduction in natural forests, while the local socioeconomic situation stays precarious. The baseline scenario parts from an analysis of historic LUCC processes and shows the consequences of LUCC tendencies: 73% of temperate forests and 50% of tropical forests would get deforested until 2030. In the variant scenario, these tendencies are adjusted to planning goals extracted from official documents and recent changes in public policies. The alternative scenario further addresses policy options for fostering conservation and sustainable development, but because of the time lag of implementation, still 59% of temperate forests and 36% of tropical forest would get lost until 2030. Nevertheless, this represents a reduction of 13% of forest loss and 11% less pastureland due to the proposed measures of conservation, and sustainable management, including strategies for reforming agricultural systems, agricultural and forestry policies and trade, land tenure and livelihood risk management.     

Predicting hot-spots of land use changes in Italy by ensemble forecasting

In the context of environmental change projections at the regional level, not only the climate but also the land use plays a key role. The limited availability of historical information reduces the possibility to calibrate land use change (LUC) models. Even in case of successful calibration, using it both for diagnostic and prognostic studies does not guarantee the reliability of single future simulations. Through ensemble forecasting, useful LUC predictions are evaluable. In this work, after introducing a modified version of the well-assessed CLUE-S model, we present reasonable hot-spots of LUC in Italy for the end of 21st century, derived from the agreement of a 32 simulation ensemble performed alternating two choices for five model configurations or inputs: (1) two different climate projections (reflecting A2 and B2 emission scenarios by IPCC, respectively); (2) two different degrees (slight and strong) of demographic increase; (3) the conservation (or not) of protected areas; (4) the influence (or not) among adjacent land uses in determining their shift; and (5) the importance (or not) of past/recent LUC trends. Results, in terms of LUC hot-spot distribution, were evaluated at administrative, biogeographical, physiographic, and watershed level. The main findings highlighted that some trends of land use substitution will be likely opposite to the past and that a more detailed spatial scale can detect situations neglected by coarser scale evaluations, and due to different transpositions of directives from high-levels to local scales. Biogeographical and physiographic settings seem strongly influencing LUCs, and administrative and catchment units across Italy show very different developments and a highly fragmented territory in terms of LUC hot-spots, all that to be considered in landscape and resource planning.     

Determination of the optimal land use allocation pattern in Nowshahr County,Northern Iran

Regional models of land use change are evaluated as a way of identifying land use pattern based on recent quantitative and probabilistic approaches. Differentiation between models in this area is the result of the approach to the concept of land use and type of indicators used in the modeling process. Since the determination of the optima land use pattern, due to the different uses of land based on the availability of regional capabilities and spatial difference in land use, depends on an integrated model, there must be a model that can assess the existing conditions of the region and present reasonable models of land use according to regional capacities and potentials. In this research, we developed a model to present the Optimal Land Use Allocation Pattern (OLUAP) for maximizing the advantages of change and determining the methods of influencing land use change priorities. This model uses spatial models and analysis, moderates the cost-benefit function, and calculates the allocation priorities of various areas based on regional conditions. The model results show that a wide scope of Nowshahr area is allocated to natural and agricultural uses. At the same time, a limited area has been assigned to urban and industrial uses. In addition, it shows that northern strip of the region due to higher accessibility of services and infrastructures is more suited than other regions to urban and industrial areas, and these two uses have first and second priority, respectively. Besides, according to the man-made environment and the special environmental conditions, the model allocates the central lowlands and southern parts sporadically to agricultural and natural areas as first and second priorities. Since the model is spatial optimization, the suggestions of the model show the OLUAP. Therefore, one can see the optimal condition for each plot and compare it with the existing land use.     

Simulating and delineating future land change trajectories across Europe

Explorations of future land use change are important to understand potential conflicts between competing land uses, trade-offs associated with particular land change trajectories, and the effectiveness of policies to steer land systems into desirable states. Most model-based explorations and scenario studies focused on conversions in broad land use classes, but disregarded changes in land management or focused on individual sectors only. Using the European Union (EU) as a case study, we developed an approach to identifying typical combinations of land cover and management changes by combining the results of multimodel simulations in the agriculture and forest sectors for four scenarios from 2000 to 2040. We visualized land change trajectories by mapping regional hotspots of change. Land change trajectories differed in extent and spatial pattern across the EU and among scenarios, indicating trajectory-specific option spaces for alternative land system outcomes. In spite of the large variation in the area of change, similar hotspots of land change were observed among the scenarios. All scenarios indicate a stronger polarization of land use in Europe, with a loss of multifunctional landscapes. We analyzed locations subject to change by comparing location characteristics associated with certain land change trajectories. Results indicate differences in the location conditions of different land change trajectories, with diverging impacts on ecosystem service provisioning. Policy and planning for future land use needs to account for the spatial variation of land change trajectories to achieve both overarching and location-specific targets.

     

Fine-grain spatial patterning and dynamics of land use and agrobiodiversity amid global changes in the Bolivian Andes

Our research addresses the gap in scientific research on the fine-grain spatial patterns and social–ecological interactions of land use and agrobiodiversity. The spatial dimension of agrobiodiversity dynamics potentially strengthens the social–ecological resilience and food security of smallholders by buffering risk and vulnerability. Our research integrates the scientific theories, concepts, and methods of spatial externalities, social–ecological interactions, geospatial land and global change sciences, and political ecology. We designed a case study of the Arbieto-Tarata landscape in the Bolivian Andes that comprises a globally significant agrobiodiversity hot spot of Andean maize. The Arbieto-Tarata landscape, which contains nearly 8000 fields at 2500–2800 masl, is representative of mixed-use smallholder agri-food systems amid global changes. Our research predicts spatial spillover and edge effects of combined social and environmental factors leading to the clustering of same-crop fields. Findings reveal significant levels of the predicted clustering between 2006 and 2012. The degree of this clustering is found to differ among geographic and environmental sub-areas reflecting fine-grain variation of local causal linkages. Extra-local causal linkages include high levels of migration, water resource shortages, and urbanization. Results show the influences of informal and formal coordination in the spatial clustering of same-crop fields. This field-level coordination improves the efficiency of resource allocations and lowers costs of production. It enables the viability of high-agrobiodiversity Andean maize in smallholder land use and agri-food systems amid global changes. The article discusses the broader policy and scientific implications of these findings including scaling up and support of the social–ecological resilience of agrobiodiversity globally.     

Quantification of land use/land cover changes in Pearl River Delta and its impact on regional climate in summer using numerical modeling

This study quantified land use/land cover (LULC) changes in Pearl River Delta (PRD) of South China and its impact on regional climate over the last two decades. The LULC change analyses were accomplished by applying a change detection method to a set of Landsat imagery and ancillary data acquired from 1970s to 2000. The results indicate that the urban expansion is the prevailing LULC change in the PRD. Impact of LULC change on regional climate was simulated by using a mesoscale climate model. Two different land cover datasets circa 1990 and 2000 were input to the model to investigate the impact of urbanization on regional weather and climate condition in summer 2005. The simulation results show that rapid urban expansion can substantially alter regional climate conditions in the PRD region including monthly mean temperature, precipitation, moisture, and surface heat fluxes.     

Multicriteria decision-making for efficient water and land resources allocation in irrigated agriculture

The irrational use of water in agriculture is often responsible for several problems concerning the depletion and/or the pollution of water resources. In these cases specific policy measures should be taken to protect water resources from harmful agricultural activities, mitigating at the same time their potential impact on farmers’ welfare. To this end, a multicriteria decision-making model is formulated that aims at allocating efficiently water and land resources in a rural area of Greece, by optimizing a set of important socio-economic and environmental objectives. According to the model’s output, past and current decisions on irrigated agriculture turned out to be oriented towards meeting exclusively the socio-economic objectives. Yet, there are several other possible allocations schemes that could be applied in order to improve the performance of environmental indicators and to contribute to a more sustainable use of natural resources. Moreover, the decision-making model can be further employed to assess a number of additional policy measures in irrigated agriculture. In this framework, the outcome of imposing various water pricing policies was evaluated. The efficiency of these policies was found tightly connected to the elasticity of water demand. Namely, higher elasticity seems to enhance the flexibility in resource allocation and the movement towards environmental objectives. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

My land? Your land? Scotland?—understanding sectoral similarities and differences in Scottish land use visions

Understanding agreement and differences between land use visions forms a first step for assessing and comparing alternative pathways towards a sustainable future. This study presents an analysis of 20 semi-structured interviews with representatives of the principal land use sectors in Scotland. The aim was to understand what, in their ideal vision, they would want rural Scotland to look like in 2050. Inductive content analysis was used to identify similarities and differences amongst interviewees. There was general agreement on the following: the importance of the environment; the wish for more partnerships, dialogue and collaboration; the desire for society to be more engaged and aware about land use; and a strong need for short-, medium- and long-term policies helping to achieve these goals. The most notable differences relate to land ownership and governance. The outcomes form a basis for further facilitated discussions, emphasising common ground and exploring where, how and to what degree land use sectors can prepare and plan in the light of uncertainties posed by Brexit and climate change. The method was effective for understanding commonalities and differences between stakeholder groups and is transferable to other countries or regions.

     

农村居民点整理对农户土地投入影响研究

近年来,农村居民点整理被作为城乡统筹发展的重要措施,在各地广泛开展。其在改善农民居住环境、为工业化和城镇化发展置换建设用地空间的同时,也对区域农地资源可持续利用产生了巨大冲击,其中,土地投入变化是农户响应这些冲击的重要表现。本研究沿着"农村居民点整理-区域土地利用条件变化-农户土地利用行为响应"的逻辑思路,形成了农村居民点整理对农户土地投入影响的分析框架,并在此基础上,从总体效应和不同政策影响两个层次,构建了农村居民点整理对农户土地投入影响的两个模型。依据江苏省调研数据,从资金和劳动力两个方面,实证分析农村居民点整理项目对农户土地投入的净效应,以及不同居民点整理政策对农户土地投入的影响方向和大小。结果表明,农村居民点整理促进了农户的土地资金投入,但对农户的土地劳动力投入具有负向影响。不同居民点整理政策对农户土地投入的影响具有显著差异,其中,置换住房的宅基地补偿政策和农地产权稳定政策对农户的土地资金投入具有较好的积极作用,而安置公寓房政策则更可能带来农户土地资金投入减少;农地产权稳定政策和安置公寓房政策显著负向影响农户土地劳动投入,但宅基地补偿政策对农户土地劳动投入影响不显著。本研究对这些结果进行了合理解释,同时也估算了户主年龄、户主受教育程度、农业收入比例、非农就业水平、农业补贴收入、耕作距离和土地经营面积等控制变量对农户土地投入的影响情况。最后从强化规划引导、内涵拓展、宅基地补偿策略优化、土地流转制度完善等方面,提出农村居民点整理政策调整和合理引导农户土地投入行为的对策建议。     

Future land use and land cover in Southern Amazonia and resulting greenhouse gas emissions from agricultural soils

Regional Environmental Change - The calculation of robust estimates of future greenhouse gas emissions due to agriculture is essential to support the framing of the Brazilian climate change...     

Uncertainty in the difference between maps of future land change scenarios

It is essential to measure whether maps of various scenarios of future land change are meaningfully different, because differences among such maps serve to inform land management. This paper compares the output maps of different scenarios of future land change in a manner that contrasts two different approaches to account for the uncertainty of the simulated projections. The simpler approach interprets the scenario storyline concerning the quantity of each land change transition as assumption, and then considers the range of possibilities concerning the value added by a simulation model that specifies the spatial allocation of land change. The more complex approach estimates the uncertainty of future land maps based on a validation measurement with historic data. The technique is illustrated by a case study that compares two scenarios of future land change in the Plum Island Ecosystems of northeastern Massachusetts, in the United States. Results show that if the model simulates only the spatial allocation of the land changes given the assumed quantity of each transition, then there is a clearly bounded range for the difference between the raw scenario maps; but if the uncertainties are estimated by validation, then the uncertainties can be so great that the output maps do not show meaningful differences. We discuss the implications of these results for a future research agenda of land change modeling. We conclude that a productive approach is to use the simpler method to distinguish clearly between variations in the scenario maps that are due to scenario assumptions versus variations due to the simulation model.     

Climate change, drought risk and land capability for agriculture: implications for land use in Scotland

Land capability classification systems define and communicate biophysical limitations on land use, including climate, soils and topography. They can therefore provide an accessible format for both scientists and decision-makers to share knowledge on climate change impacts and adaptation. Underlying such classifications are complex interactions that require dynamic spatial analysis, particularly between soil and climate. These relationships are investigated using a case study on drought risk for agriculture in Scotland, which is currently considered less significant than wetness-related issues. The impact of drought risk is assessed using an established empirical system for land capability linking indicator crops with water availability. This procedure is facilitated by spatial interpolation of climate and soil profile data to provide soil moisture deficits and plant available water on a regular 1-km grid. To evaluate potential impacts of future climate change, land capability classes are estimated using both large-scale ensemble (multi-simulation) data from the HadRM3 regional climate model and local-scale weather generator data (UKCP09) derived from multiple climate models. Results for the case study suggest that drought risk is likely to have a much more significant influence on land use in the future. This could potentially act to restrict the range of crops grown and hence reduce land capability in some areas unless strategic-level adaptation measures are developed that also integrate land use systems and water resources with the wider environment.