Mapping and monitoring the impacts of climate variabilities on rangelands in North Darfur, Sudan
Date
2022
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Abstract
In North Darfur, rangelands are of great importance as they support economic activities such as pastoralism and help in environmental management by reducing desertification. However, alterations or shifts in rangelands may take place due to climate variabilities posing problems for resource and land managers as they seek to familiarise to variations in the environment and monitor and partially control effects of climate variability. Shifts in rangeland quality and quantity which may be experienced owing to climate variabilities pose problems for environmental managers as they are working on conserving and mitigate adverse impacts of climate variabilities on rangelands. The region has experienced various environmental and social impacts because of its ecological structure and geographical location. Massive alteration of the rangelands on farmlands have been experienced, leading to conflicts between farmers. Therefore, the monitoring of the rangelands for a longer season in North Darfur could lead to the increase in rangeland productivity. Conventionally, field-based surveys including focus groups, in-depth interviews, ethnography, questionnaires, and intercepts were implemented to monitor land use changes on bare land, rangelands, waterbodies, and farmlands. However, these methods have low spatial coverage making them unreliable in studying land uses and land cover change, especially over long periods of time. In this study, remote sensing (RS) Landsat 4,5,7 and 8 images and temperature and rainfall products were used for the period between 1985 and 2020 at five-year intervals. For each image, 29 scenes were downloaded to cover the whole study area. Using the climate data, rainfall and temperature anomalies were calculated to quantify climatic trends. Random forest classification was run in Aeronautical Reconnaissance Coverage Geographic Information System (ArcGIS). The land cover classes used in this study were bare land, farmlands, rangelands, and water bodies. Additionally, the Soil Adjusted Vegetation Index (SAVI) was used monitoring rangeland productivity in North Darfur. The findings of the study outlined and proved the early part of the period studied rangelands were dominant, covering up to 20% of the study area. Rangelands also covered most of the southern parts of the study area. However, by 2020, rangelands only covered 8% of the total area. Waterbodies concurrently decreased significantly, covering just 1% in 2020, where previously they had covered 18%. In contrast, farmlands became more dominant in the southern part of North Darfur by 2020, covering 33% of the total area while bare grounds increased to 58%. It is recommended that the government and the environmental managers in Sudan implement measures that help in safeguarding rangelands for sustainability.
Description
Research Report submitted in partial fulfilment of the requirements for the degree of Master of Science in Geographical Information Systems and Remote
Sensing to the Faculty of Science, School of Geography, Archaeology & Environmental Sciences, University of the Witwatersrand, Johannesburg
Keywords
Rangelands, Climate variabilities