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1.
Negative environmental impacts of violent conflict have been observed worldwide. Whether or not active global conflicts are declining in number remains hotly debated, the number of countries entering post-conflict periods is on the rise, and the impact of this transition on land cover changes remains poorly understood. In Colombia, though large-scale armed conflict has concluded, the post-conflict period represents an ongoing threat to forest conservation, putting at risk commitments to meet global conservation goals and even those stipulated in the peace accord. This paper aims to assess land cover change associated with the Colombian conflict in the Andes-Amazon region between 1988 and 2019. First, we use the Landsat archive to map land cover and characterize the spatial patterns of change at the regional level. Second, to empirically identify the effect of conflict on land cover change, we employ a difference-in-difference approach using local conflict events data. During conflict (1988–2011), land cover in the Andes-Amazon remained relatively stable, however during the post-conflict period (2012–2019), the conversion from forest to agriculture increased by 40%. We find that forest cover surrounding conflict events (1 km radius) decreased significantly, on average by ~ 19% during conflict, which accelerated to ~ 30% in the post-conflict period. Similarly, agriculture expansion is most substantial during the post-conflict period, but exclusively in municipalities with population below the 50th percentile. Landscape metrics show that in peripheral municipalities (<50th), agriculture occurs in clumped distributions during the conflict period. Meanwhile, during the post-conflict period, this expansion happens more quickly, with significantly greater agricultural patch sizes than during the conflict period. We conclude that a slow implementation of conservation governance, the emergence of illegal land markets, and illicit land uses (i.e., coca and illegal cattle ranching) may accelerate land cover change in the coming years. 相似文献
2.
城市化进程下土地利用格局变化以及驱动力分析是当前国内学者研究的热点。本文利用C5决策树分类方法分别提取北京、上海1990s以来的三期遥感影像分类图,揭示两市城市用地格局变化的空间规律及其异同点。结果表明:过去的20 a来北京地区以北京市辖区为中心呈现低密度式蔓延扩张;上海城市用地呈“单中心、多卫星城”同时扩张,并且东部沿江地区发展速度较快。将研究区按扩张程度分为:高度扩张区、中度扩张区、低度扩张区。从空间上看,上海城市用地扩张比北京明显,在扩张的过程中占用了大量耕地,上海地区尤为明显。同时,人口增长、产业结构调整等是城市化进程中土地利用变化的主要驱动力因子,需要将来更多的相关研究。 相似文献
3.
The paper analyses land use trajectories in savannah woodlands in the Central-West Region, Burkina Faso and the Upper East Region in northern Ghana by use of satellite images and historical archives. Observed trends differ in terms of spatial location and correlation with population pressure from normally accepted characterizations. Colonial forestry policies are proposed as key determinants of present-day land use patterns. However, these reinforced pre-colonial land use patterns inasmuch as land gazetted as forest reserves were tracts affected by vectors of human and livestock disease. It is suggested that the transformation of wooded agricultural landscapes in the Sudano-Sahelian region is the outcome of historically and culturally embedded interactions between complex social, economic and ecological processes which operate at widely varying scales and which change over time; the implications hereof for modelling of global environmental issues is discussed. 相似文献
4.
Long-term studies of land system change can help providing insights into the relative importance of underlying drivers of change. Here, we analyze land system change in Germany for the period 1883–2007 to trace the effect of drastic socio-economic and institutional changes on land system dynamics. Germany is an especially interesting case study due to fundamentally changing economic and institutional conditions: the two World Wars, the separation into East and West Germany, the accession to the European Union, and Germany's reunification. We employed the Human Appropriation of Net Primary Production (HANPP) framework to comprehensively study long-term land system dynamics in the context of these events. HANPP quantifies biomass harvests and land-use-related changes in ecosystem productivity. By comparing these flows to the potential productivity of ecosystems, HANPP allows to consistently assess land cover changes as well as changes in land use intensity. Our results show that biomass harvest steadily increased while productivity losses declined from 1883 to 2007, leading to a decline in HANPP from around 75%–65% of the potential productivity. At the same time, decreasing agricultural areas allowed for forest regrowth. Overall, land system change in Germany was surprisingly gradual, indicating high resilience to the drastic socio-economic and institutional shifts that occurred during the last 125 years. We found strikingly similar land system trajectories in East and West Germany during the time of separation (1945–1989), despite the contrasting institutional settings and economic paradigms. Conversely, the German reunification sparked a fundamental and rapid shift in former East Germany's land system, leading to altered levels of production, land use intensity and land use efficiency. Gradual and continuous land use intensification, a result of industrialization and economic optimization of land use, was the dominant trend throughout the observed period, apparently overruling socio-economic framework conditions and land use policies. 相似文献
5.
A significant challenge in resource management is addressed: the perceived trade-off between economic growth and ecosystem restoration and conservation. Traditional approaches to management regard restoration as a potential cost to economic productivity. In this study we show that by considering a broader range of economic values, including ecosystem services values, an argument can be made that restoration of lake ecosystems also leads to favourable economic outcomes when commonly disregarded values are considered. Our case study analyses the ecological outcomes of different catchment mitigation and land use scenarios in terms of water quality results in a lake, assessing changes in land use values based on opportunity costs, and ecosystem services values. We show that when considering the value of ecosystem services, intensive agricultural land use is not necessarily the most economically valuable form of land use within a lake catchment. Indeed, a shift towards alternative land uses within a catchment can lead to both ongoing economic benefits and improvements in water quality. In this context, land-use change offers an option for water quality improvement that minimises lake and land mitigation costs, while adding value to catchment land use. An argument is made supporting land use change towards indigenous forest types, which can sustain alternative sources of income such as a range of recreational values, while supporting important ecosystem functions for the region. 相似文献