Journal of Geography, Environment and Earth Science International

Quantifying Forest Cover Change at District and Forest Reserve Levels in Southern and Eastern Sierra Leone Using Landsat Data

Thu, 29 Oct 2026 00:00:00 +0000

Aim: In Sierra Leone, the paucity of data on forest cover distribution and degradation limits the design and implementation of forest protection measures and the evaluation of the effectiveness of such measures. In view of the above, this study presents the first comparative analysis of district-level and forest reserve-level forest cover change in Sierra Leone, using a case study of the southern and eastern regions of the country.

Study Design: A case-study research design and a remote-sensing approach using optical satellite imagery were adopted to quantify forest cover change at district and reserve levels over a 40-year interval.

Place and Duration of Study: The study mapped and quantified forest cover change in Moyamba and Bo (Southern Region) and Kenema and Kailahun (Eastern Region) districts in 1986 and 2026. For each district, a forest reserve was identified and changes in its forest cover over the four decades were mapped and quantified.

Methodology: Landsat imagery was acquired in 1986 (Landsat-5) and 2026 (Landsat-8). A simplified land-use land-cover (LULC) classification scheme was adopted, comprising six classes: forest, farm bush, grassland, mangrove, water body and others, to which the Support Vector Machine (SVM) classifier was applied. Post-classification change detection was used to quantify LULC changes, and the corresponding district- and forest reserve-level statistics were summarised in bar charts. Accuracies were assessed using confusion matrices based on Google Earth imagery and ground-truth data for the 1986 and 2026 LULC maps, respectively.

Results: The LULC classification achieved overall accuracies of 85.9% for the 1986 map and 96.6% for the 2026 map, and the higher accuracy recorded in the 2026 map is attributable to the improvement in radiometric resolution in Landsat-8 relative to Landsat-5. Forest declined across all districts, and a similar trend was recorded at the forest reserve level, except for Kangari in Bo, which recorded a slight increase of 1.4%. The decline in forest occurred in tandem with increases in either farm bush or grassland, or both. The overall decline in forest cover at the district level was greater (-35.2%) than that at the forest reserve level (-12.2%). Moyamba District, which is located along the Atlantic coast recorded a substantial decline (-28.6%) in mangrove.

Conclusion: The lesser forest loss in forest reserves suggests a possible effect of protection measures. However, as unprotected forests decline, protected forests and mangroves would face increasing threats. Thus, there is a need to understand the dynamics of community forests, protected forests, and forest reserves. Moreover, studies are required of transboundary forest reserves, such as the Gola Forest, where cross-border differences in approaches and priorities have varying implications for forest management.

Towards a Cadastral Domain Model for Kenya’s Land Information Systems

Collins Mwange — Sat, 31 Oct 2026 00:00:00 +0000

Kenya has pursued several initiatives to digitise land records, including ArdhiSasa, yet cadastral information remains fragmented across administrative and technical systems. Inconsistent data structures and the absence of a common conceptual model complicate the representation of parcels, rights, restrictions and related transactions. This study aimed to develop a Unified Modelling Language (UML) cadastral domain model appropriate to Kenya’s land administration context. A desk review of relevant research, government reports and statutory provisions was used to identify domain entities, attributes and relationships. A draft model was then examined and refined using questionnaire responses from land administration and geospatial practitioners reached through the Institution of Surveyors of Kenya. The proposed model represents actors, spatial units and legal interests through classes including Person, Property, Tenure and Interest. It also describes property conversion, spatial aggregation, adjacency, registration records, survey-related information and financial transactions associated with land administration. Inheritance, associations and associative classes are used to express the relationships between these entities without committing the conceptual structure to a particular software platform. The model provides an organised description of cadastral information that may inform the design of land information management systems and support future efforts towards data consistency and interoperability. As the study focuses on conceptual modelling and expert review, the operational suitability of the model requires further evaluation through system implementation and testing.

Avian Diversity and Abundance in the Muga Silkworm (Antheraea assamensis) Ecosystem of Assam Across Larval Instars and Agro-climatic Zones

Mon, 09 Nov 2026 00:00:00 +0000

Open rearing of the muga silkworm (Antheraea assamensis) exposes developing larvae to a diverse assemblage of visiting birds. This study characterised avian abundance, species richness, Shannon diversity and predatory/depredatory composition at six muga-rearing locations in Assam's Upper Brahmaputra Valley Zone (UBVZ; Sivasagar) and North Bank Plain Zone (NBPZ; Lakhimpur), covering all five larval instars. Line-transect observations conducted during the Chotua and Jethua rearing seasons in 2020–2022 yielded 9,724 bird records. The NBPZ accounted for 5,961 records (61.3%), compared with 3,763 (38.7%) in the UBVZ. Across locations, the mean classified composition was 66.45% predatory and 33.55% depredatory birds. Gobindapur had the greatest overall abundance (2,238 records) and species richness (43 species), whereas MSDP Borahibari had the lowest (1,167 records; 29 species). Abundance was highest during the third instar (2,949 records) and lowest during the first instar (1,035 records); mean Shannon diversity also peaked in the third instar (3.011). Maximum single-location richness, however, was greatest during the fourth instar (34 species). During the fourth and fifth instars combined, common myna was the most abundant species in both districts. These descriptive patterns indicate that bird visitation varies spatially and across larval development. Because bird counts do not directly measure predation or silkworm mortality, the findings support stage-specific monitoring and consideration of non-harmful management rather than estimates of bird-induced crop loss.

CA–Markov Urbanisation Scenario for 2021–2050 and Historical Landscape Metrics along the Mumbai–Agra Highway in Nashik District India

Charushila Diliprao Nikam, Santosh A. Bhailume — Tue, 10 Nov 2026 00:00:00 +0000

Urbanisation along major transport corridors can redistribute land-use pressure beyond existing built-up cores but overlapping buffer summaries may obscure the location of prospective conversion. This study evaluates a conditional 2050 land-use and land-cover (LULC) scenario for the Mumbai–Agra National Highway corridor in Nashik District, India, using historical evidence for 1991–2021. The documented classification workflow combined Object-Based Image Analysis and Random Forest classification of four Landsat datasets; reported overall accuracies ranged from 91.8% to 94.1%. The present analysis audits the scenario tabulations and derives non-overlapping distance rings from cumulative 2 km, 5 km and 10 km buffers. Percentages recalculated from the reported class areas and fixed buffer extents indicate that built-up share increases from 39.60% to 62.27%, 31.02% to 55.57% and 20.27% to 51.63%, respectively. In the 5–10 km ring, built-up share increases from 9.52% to 47.70%, with a compound annual growth rate of 5.72%; this ring accounts for 60.87% of the projected built-up increment within 10 km. Historical landscape indices report increasing patch subdivision and dominance, but unspecified calculation levels and inconsistent metric metadata prevent firm class-specific ecological conclusions. The 2050 class-area totals differ from the stated buffer extents by +0.04 km², −0.40 km² and +1.00 km². Transition matrices, suitability weights, cellular settings, hindcast validation and sensitivity results are unavailable, so the scenario is not independently reproduced or validated. The ring comparison identifies where the reported scenario concentrates potential conversion pressure and supports conditional, distance-specific planning priorities.

Hydro-Climatic and Environmental Influences on Population Vulnerability to Typhoid Fever in Lagoon Communities of Douala IV Municipality, Cameroon

Philip Fon Gah, Zephania Nji Fogwe — Tue, 10 Nov 2026 00:00:00 +0000

Low-lying lagoon settlements may experience flooding, impaired drainage and faecal contamination of domestic water sources, but these mechanisms are not equivalent to demonstrated typhoid transmission. This observational study describes monthly climatic conditions, four related typhoid-report series and environmental exposure indicators in six communities of Douala IV Municipality, Cameroon. The available records comprise monthly rainfall and temperature for 2025, field-survey reports, health-centre records, laboratory-labelled reports, and summary information for 180 households. Monthly reporting series were compared using descriptive statistics and exploratory Pearson correlations; an ordinary least-squares model and a study-specific equal-weight normalised index were also assessed. Rainfall rose from 30 mm in December to 742 mm in August. The field, health-centre and laboratory series contained 4,138, 5,532 and 4,716 annual records, respectively. Their arithmetic sum (14,386) was not established as a count of distinct patients because record overlap could not be assessed. The monthly sum peaked in April (1,715) and reached its minimum in August (868). Rainfall was not significantly correlated with the monthly sum (r = −0.430, p = .163); the temperature association was also non-significant (r = .474, p = .119). A two-predictor model explained 22.5% of its variation (R² = .225, p = .317). Among households, 72.2% reported frequent flooding, 52.8% poor drainage and 61.1% use of open or closed wells. Faecal-coliform positivity was reported in 56.45% of tested water samples, although test counts and protocols were unavailable. A descriptive composite index averaged 0.396; it is not an independently validated infection-risk measure. These findings document substantial environmental exposure potential and differences among surveillance sources, but cannot establish population incidence or causal climatic effects.