Long-term land cover change in Zambia: An assessment of driving factors

2019 ◽  
Vol 697 ◽  
pp. 134206 ◽  
Author(s):  
Darius Phiri ◽  
Justin Morgenroth ◽  
Cong Xu
CATENA ◽  
2017 ◽  
Vol 151 ◽  
pp. 63-73 ◽  
Author(s):  
Samuel Bouchoms ◽  
Zhengang Wang ◽  
Veerle Vanacker ◽  
Sebastian Doetterl ◽  
Kristof Van Oost

2013 ◽  
Vol 8 (1) ◽  
pp. 084596 ◽  
Author(s):  
Zhongchang Sun ◽  
Xinwu Li ◽  
Wenxue Fu ◽  
Yingkui Li ◽  
Dongsheng Tang

Author(s):  
Peter Caccetta ◽  
Suzanne Furby ◽  
Jeremy Wallace ◽  
Xiaoliang Wu ◽  
Gary Richards ◽  
...  

2015 ◽  
Vol 12 (6) ◽  
pp. 5219-5250 ◽  
Author(s):  
A. Molina ◽  
V. Vanacker ◽  
E. Brisson ◽  
D. Mora ◽  
V. Balthazar

Abstract. Andean headwater catchments play a pivotal role to supply fresh water for downstream water users. However, few long-term studies exist on the relative importance of climate change and direct anthropogenic perturbations on flow regimes. In this paper, we assess multi-decadal change in freshwater provision based on long time series (1974–2008) of hydrometeorological data and land cover reconstructions for a 282 km2 catchment located in the tropical Andes. Three main land cover change trajectories can be distinguished: (1) rapid decline of native vegetation in montane forest and páramo ecosystems in ~1/5 or 20% of the catchment area, (2) expansion of agricultural land by 14% of the catchment area, (3) afforestation of 12% of native páramo grasslands with exotic tree species in recent years. Given the strong temporal variability of precipitation and streamflow data related to El Niño–Southern Oscillation, we use empirical mode decomposition techniques to detrend the time series. The long-term increasing trend in rainfall is remarkably different from the observed changes in streamflow that exhibit a decreasing trend. Hence, observed changes in streamflow are not the result of long-term climate change but very likely result from direct anthropogenic disturbances after land cover change. Partial water budgets for montane cloud forest and páramo ecosystems suggest that the strongest changes in evaporative water losses are observed in páramo ecosystems, where progressive colonization and afforestation of high alpine grasslands leads to a strong increase in transpiration losses.


Author(s):  
Ondřej Skoupý ◽  
David Procházka

Land cover change analysis is one of the most important tools for landscape management purposes, as it enables exploring of long-term natural processes especially in contrast with anthropogenic factors. Such analysis is always dependent on quality of available data. Due to long tradition of map making and quality and accuracy of preserved historical cartographic data in the Czech Republic it is possible to perform an effective land use change analysis using maps dating even back to early nineteenth century. Clearly, because map making methodology has evolved since then, the primary problem of land cover change analysis are different sources and thus different formats of analyzed data which need to be integrated, both spatially and contextually, into one coherent data set. One of the most difficult problems is caused by the fact that due to different map acquisition methodologies the maps are loaded with various errors originating from measurement, map drawing, storage, digitalization and finally georeferencing and possible vectorization. This means that some apparent changes may be for example caused by different methodology and accuracy of mapping a landscape feature that has not actually changed its shape and spatial position through the time. This work deals with spatial integration of data, namely identifying corresponding lines in map layers from different epochs and adjusting the borders plotted in the less accurate map to spatially correspond to the more accurate map. For such a purpose, a special program had to be created. It basically follows the work by Malach et al., 2009 who introduced their Layer Integrator. This work however presents a significantly different approach to creating an integration tool.


2020 ◽  
Vol 12 (24) ◽  
pp. 4048
Author(s):  
Yrneh Ulloa-Torrealba ◽  
Reinhold Stahlmann ◽  
Martin Wegmann ◽  
Thomas Koellner

The monitoring of land cover and land use change is critical for assessing the provision of ecosystem services. One of the sources for long-term land cover change quantification is through the classification of historical and/or current maps. Little research has been done on historical maps using Object-Based Image Analysis (OBIA). This study applied an object-based classification using eCognition tool for analyzing the land cover based on historical maps in the Main river catchment, Upper Franconia, Germany. This allowed land use change analysis between the 1850s and 2015, a time span which covers the phase of industrialization of landscapes in central Europe. The results show a strong increase in urban area by 2600%, a severe loss of cropland (−24%), a moderate reduction in meadows (−4%), and a small gain in forests (+4%). The method proved useful for the application on historical maps due to the ability of the software to create semantic objects. The confusion matrix shows an overall accuracy of 82% for the automatic classification compared to manual reclassification considering all 17 sample tiles. The minimum overall accuracy was 65% for historical maps of poor quality and the maximum was 91% for very high-quality ones. Although accuracy is between high and moderate, coarse land cover patterns in the past and trends in land cover change can be analyzed. We conclude that such long-term analysis of land cover is a prerequisite for quantifying long-term changes in ecosystem services.


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