4 research outputs found
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Future trade-offs to 2050: land cover change, biodiversity and agriculture in Zambia
In Zambia, demand for cereal to feed a growing population is predicted to
double by 2050. As pressure on agricultural land increases, there is an urgent
need to develop tools to minimise conflicts between competing land uses
Evaluating the land cover dynamics in the protected areas using GIS and Remote sensing techniques:the case of Nyerere National Park, Tanzania
Understanding land cover dynamics of protected areas is one area of active research and several studies have been done in this direction. However, such studies are limited with few parameters and lack a long-range spatial-temporal analysis to effectively understand land cover dynamics and thereby helping countries manage their protected areas sustainably. This research used Nyerere National Park (NNP) to explore its land cover dynamics from 1991 to 2021 and projected to 2050, vegetation health from 2000 to 2021 and surrounding human population from 1988 to 2021. The park’s land cover of 1991 and 2021 was explored using a smileCart classifier after training 897 samples of water, bareland, grassland, bushland and forest from the Landsat imagery. Its 2050 land cover was simulated using CA-Markov model. The park's vegetation health was studied using NDVI and EVI from the Landsat and MODIS imagery. Land cover classes with significant changes are forest and grassland. The forest areas showed a decreasing trend from 62%-to-52%-to-41% from 1991-to-2021-to-2050, while the grassland areas showed an increasing trend from 9%-to-17%-to-24%. The maximum NDVI values from the Landsat imagery showed a minimal decrease from 0.76 in 1991 to 0.75 in 2021. Many park’s areas have weak vegetation based on the overall NDVI and EVI results. The study also identified rapid increase in human population around the park, and agricultural activities taking place in some of its areas. The results of this study provide a new reference to NNP and other studies in all other protected areas
Agricultural expansion into forest reserves in Zambia: a remote sensing approach
Forest reserves play an important role in the provision of ecosystem goods and services; however, these reserves are facing increasing anthropogenic impacts primarily because of agricultural activities. In sub-Saharan Africa, studies on understanding the extent and impacts of agricultural expansion into forest reserves are generally lacking. Thus, this study aimed to assess the extent of agricultural expansion into forest reserves in Zambia on a national scale between 2000 and 2018 and explores the drivers. We used a remote sensing approach by employing Google Earth Engine (GEE) and Random Forests classifier to map land cover changes at five-time steps: 2000, 2005, 2010, 2015 and 2018. Landsat images were used to map six land cover classes (forest, cropland, wetland, grassland, settlement, and water body) determined by the Intergovernmental Panel on Climate Change (IPCC). A social survey was also undertaken to understand the drivers of agricultural expansion into forest reserves at two study sited located in eastern and north-western part of Zambia. Based on the land cover maps which were produced with high accuracies ranging from 82% to 94%, the results indicated a general decline of 10% in forest area and an increase of 25% in cropland. Almost 50% of the forest reserves in Zambia are experiencing some form of encroachment, and 10% of these are heavily encroached (>90% loss). Local communities indicated that population growth, loss of soil fertility, high market demand for crops, land tenure system, and lack of law enforcement are the major drivers of agricultural expansion into forest reserves. This study highlights the need for policy marker to consider trade-offs in agricultural expansion and conservation of forest reserves relation to population growth. Enhancing sustainable agricultural practices and strengthening the implementation of different legislative frameworks is key in addressing the challenges of conservation, while enhancing food security