المؤلفون: Kangi, Gladys, Dondeyne, Stefaan, Kleinschroth, Fritz, Van Orshoven, Jos

المصدر: Land Degradation & Development; 1/30/2024, Vol. 35 Issue 2, p867-883, 17p

مصطلحات موضوعية: REMOTE sensing, MOTOR imagery (Cognition), EFFECT of human beings on climate change, RAINFALL, LANDSAT satellites, WATER levels

مصطلحات جغرافية: ETHIOPIA, KENYA

مستخلص: Deltas, being areas where river sediments accumulate, are sensitive to changes in climate and anthropogenic processes that affect sediment generation. The Omo Delta, on the Ethiopia–Kenya border, is constantly changing due to fluctuating lake levels, a variable climate, and rapidly changing land use. Due to field data scarcity and the region's limited accessibility, we relied on remote sensing (RS) data to investigate delta extent between 1990 and 2018 and attempted to disentangle the effect of climatic from anthropogenic variables. We obtained a time series of delta extent from Landsat imagery using Random Forest (RF) classification. Using parametric and non‐parametric regression techniques, we regressed the delta extent on Lake Turkana levels, Omo River discharges, Omo‐Gibe Basin rainfall, tree cover loss, and irrigation extent. The RF algorithm distinguished water from land with high (>90%) accuracies and revealed Omo Delta extent fluctuations ranging from 949 km2 in 1993 to 651 km2 in 2000. Lake water level, which depends on the rainfall over the Omo‐Turkana Basin, emerged as the best predictor of delta extent. However, the annual rainfall over the Omo‐Gibe Basin showed no correlation with delta extent. The regression models further show a connection between delta extent, irrigation extent, and tree cover loss. We conclude that rainfall indirectly influences delta extent across the Omo‐Turkana Basin. Regression models indicate additional cumulative effects of human activity in the Omo‐Gibe Basin but fall short in explaining delta dynamics. [ABSTRACT FROM AUTHOR]

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المؤلفون: Kerbo, Aklilu Amiga, Degaga, Degefa Tolossa, Beyene, Abebe Damte

المصدر: Land Use Policy; Jun2024, Vol. 141, pN.PAG-N.PAG, 1p

مصطلحات موضوعية: LAND cover, LAND use, EUCALYPTUS, FARMERS' attitudes, MOTOR imagery (Cognition), TREE crops, FOREST products

مصطلحات جغرافية: ETHIOPIA

مستخلص: Gurage Zone is one of the areas of Ethiopia experiencing rapid land use and land cover (LULC) changes over the past few decades. This study assessed the contribution of eucalyptus expansion to LULC changes based on a detailed household level survey, key informant interviews, focus group discussions and a set of Landsat imageries. Both descriptive statistics and econometric model were employed for the analysis of drivers of eucalyptus plantation. LULC change detection technique was used to examine the changes in LULC over time. This study achieved a mean classification accuracy of 89.17% and 0.83 overall Kappa statistics for the tree LULC maps. The result of descriptive analysis revealed that more than 42% of the sampled households have planted eucalyptus trees on crop land. The study indicated that eucalyptus plantation which was fourth in LULC ranking in 2000 has increased by 68.3% in 2021 to become the second largest land cover next to crop land. On the other hand, from 2010 to 2021, the area covered by crops showed a decline. This indicates eucalyptus tree to be the major cause of LULC change in the study area. The econometric estimation identified the micro-level drivers such as land size and access to market to be important factors influencing eucalyptus plantation. This study suggests that the rapid expansion of eucalyptus plantation on fertile soil requires an immediate policy response in order to balance food crop production and eucalyptus plantation in Gurage Zone. • The area covered by eucalyptus plantation increased from almost 12% in 2000 to 20% in 2021. • Smallholder farmers' eucalyptus tree plantations were the main cause of LULC changes. • Micro-level drivers influencing LULC changes include factors such as land size and market accessibility. • Policy actions are necessary to keep a balance between the demand for forest products and food production. [ABSTRACT FROM AUTHOR]

: Copyright of Land Use Policy is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)