scholarly journals Future Land-use Changes in the transboundary Sio-Malaba-Malakisi Basin of East Africa: Simulations using the CLUE-S model and Classified Satellite Land Cover Datasets

Author(s):  
Stanley Atonya ◽  
Luke OLANG ◽  
Lewis Morara

A comprehensive undertanding of land-use/cover(LUC) change processes, their trends and future trajectories is essential for the development of sustainable land-use management plans. While contemporay tools can today be employed to monitor historical land-cover changes, prediction of future change trajectories in most rural agro-ecological landscapes remains a challenge. This study evaluated potential LUC changes in the transboundary Sio-Malaba-Malakisi River Basin of Kenya and Uganda for the period 2017-2047. The land use change drivers were obtained through a rigorous fieldwork procedure and the Logistic Regression Model (LGM) to establish key factors for the simulation. The CLUE-S model was subsequently adapted to explore future LUC change trajectories under different scenarios. The model was validated using historical land cover maps for the period of 2008 and 2017, producing overall accuracy result of 85.7% and a Kappa coefficient of 0.78. The spatial distribution of vegetation cover types could be explained partially by proximate factors like soil cation exchange capacity, soil organic carbon and soil pH. On the other hand, built-up areas were mainly influenced by population density. Under the afforestation scenario, areas under forest cover expanded further occupying 54.7% of the basin. Conversely, under the intense agriculture scenario, cropland and pasture cover types occupied 78% of the basin. However, in a scenario where natural forest and wetlands were protected, cropland and pasture only expanded by 74%. The study successfully outlined proximate land cover change drivers, including potential future changes and could be used to support the development of sustainable long-term transboundary land-use plans and policy.

2020 ◽  
Vol 13 (7) ◽  
pp. 3203-3220 ◽  
Author(s):  
Lei Ma ◽  
George C. Hurtt ◽  
Louise P. Chini ◽  
Ritvik Sahajpal ◽  
Julia Pongratz ◽  
...  

Abstract. Anthropogenic land-use and land-cover change activities play a critical role in Earth system dynamics through significant alterations to biogeophysical and biogeochemical properties at local to global scales. To quantify the magnitude of these impacts, climate models need consistent land-cover change time series at a global scale, based on land-use information from observations or dedicated land-use change models. However, a specific land-use change cannot be unambiguously mapped to a specific land-cover change. Here, nine translation rules are evaluated based on assumptions about the way land-use change could potentially impact land cover. Utilizing the Global Land-use Model 2 (GLM2), the model underlying the latest Land-Use Harmonization dataset (LUH2), the land-cover dynamics resulting from land-use change were simulated based on multiple alternative translation rules from 850 to 2015 globally. For each rule, the resulting forest cover, carbon density and carbon emissions were compared with independent estimates from remote sensing observations, U.N. Food and Agricultural Organization reports, and other studies. The translation rule previously suggested by the authors of the HYDE 3.2 dataset, that underlies LUH2, is consistent with the results of our examinations at global, country and grid scales. This rule recommends that for CMIP6 simulations, models should (1) completely clear vegetation in land-use changes from primary and secondary land (including both forested and non-forested) to cropland, urban land and managed pasture; (2) completely clear vegetation in land-use changes from primary forest and/or secondary forest to rangeland; (3) keep vegetation in land-use changes from primary non-forest and/or secondary non-forest to rangeland. Our analysis shows that this rule is one of three (out of nine) rules that produce comparable estimates of forest cover, vegetation carbon and emissions to independent estimates and also mitigate the anomalously high carbon emissions from land-use change observed in previous studies in the 1950s. According to the three translation rules, contemporary global forest area is estimated to be 37.42×106 km2, within the range derived from remote sensing products. Likewise, the estimated carbon stock is in close agreement with reference biomass datasets, particularly over regions with more than 50 % forest cover.


Author(s):  
D. L. Cornelio

Abstract. Significant land use changes in Fiji Islands caused soil degradation, pollution and biodiversity losses. The planting of trees is an option of sustainable land use with long term ecological and economic advantages. Spatial models based on ecological requirements of tree species facilitates decision making, planning and risks management before planting. A land suitability analysis with Geographic Information System (GIS) was carried out to identify areas in Vitilevu island for the planting of eleven native and exotic tree species. Altitudes, rainfall and forest cover maps were used as discrimination factors in boolean operations. The species with higher ecological potential for plantation were Syzygium decussatum (22% of the total area), Tectona grandis (19% of the total area), and Metroxylon vitiense (18% of the total area). The model is robust but can be enhanced by adding thematic layers of other environmental factors.


Land ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 99 ◽  
Author(s):  
David Fernández-Nogueira ◽  
Eduardo Corbelle-Rico

This work aims to provide a comprehensive, wall-to-wall analysis of land use/cover changes in the continental areas of Portugal and Spain between 1990 and 2012. This overall objective is developed into two main research questions: (1) Whether differences between the extent and prevalence of changes exist between both countries and (2) which are the hotspots of change (areas where a given land use/cover transition dominates the landscape) in each country. We used Corine Land Cover in three different points in time (1990, 2000, 2012) to explore eight characteristic land cover transitions and carried out a cluster analysis at LAU2 level (municipalities in Spain, parishes in Portugal) that allowed to identify the areas in which each transition was dominant. The main findings include the decline of agricultural area and the increase of urbanized and artificial covers in both countries, but different trends followed by forest cover, with an increase in Spain and a decrease in Portugal. At the same time, the spatial analysis provided an overview of the main gradients of change related to tensions between agricultural intensification–extensification, on the one hand, and deforestation–afforestation, on the other.


Author(s):  
Rahul Thapa ◽  
Vijay Bahuguna

Remote sensing and G.I.S help acquire information on changing land use and land cover (LULC), and it plays a pivotal role in measuring and monitoring such local and global changes. The present analysis has been executed on Landsat 5 TM, 1989 and Landsat 8 OLI/TIRS, 2020 images of Pachhua Dun, including Dehradun & Mussoorie urban agglomeration. The present study aims to detect the land encroachment or area of change; rate of change and monitoring spatio-temporal variation in LULC change between 1989-2020 using change detection technique, supervised maximum likelihood classification, and Overall accuracy & Kappa Coefficient (K) was applied as an accuracy assessment tool. The results derived from the change detection analysis exhibits that the highest growth rate was recorded in built-up areas +247.75% (110 km2) and revealed the annual rate of change of 3.55 km2. or  7.99%, the highest among all LULC class during the overall study period of 31 years. The result also found that among all LULC class, the most significant LULC conversion took place from agricultural land to built-up areas followed by open/scrubland and vegetation/forest cover; approximately 69.9km2 of the area under agricultural land was found to be converted into built-up areas. At the same time, 38.9 km2 area of vegetation/forest cover and 36.3 km2 of the area of open/scrubland have converted into agricultural land. Rising anthropogenic influence and unsustainable land-use practices in the study area have led to a large-scale human encroachment and rapid transformation of the natural landscape into the cultural landscape. This analysis provides the essential long-term Geospatial information related to LULC change for making optimum decision-making process and sustainable land-use planning in the Pachhua Dun-Dehradun District, Uttarakhand, India. 


Author(s):  
Judith Chepkorir Koskey ◽  
George Morara Ogendi ◽  
Charles Mwithali M'Erimba ◽  
Geoffry Mukonambi Maina

The Njoro and Kamweti River catchments are productive catchments that have and continue to experience major land-use changes with consequences on land cover and the associated environmental resources. It is, therefore, crucial to understand the type of changes occurring, spatial patterns, and the rates at which these changes are occurring. In this study, we quantified the changes in land use and land cover that occurred between 1988 and 2019 identifying areas of change and the average annual rate of change. Thematic Mappers (TM) and Enhanced Thematic Mappers Plus (ETM +) and Sentinel images were obtained for 1988 and 2019. Ground truthing was carried out to enable us to verify the accuracy of the remotely sensed data using in-situ observations to refine the classification output. The results obtained indicated that both catchments have experienced intense land-use changes but at different levels. Njoro River catchment’s forest cover and shrubland had decreased at a rate of 6.06 Km2/year and 0.92 Km2/year respectively and the most increase was recorded in farmlands (3.11 Km2/year) as the other land use classes also increased. In the Kamweti River catchment, forest cover showed a decrease at a rate of 0.21 Km2/year, and farmlands also a slight decrease of 0.1 Km2/year while the other land cover classes increased in area coverage during the period 1988-2019.  The changes in land use and land cover were attributed to increased demand for food and housing and thus continued degrading the two catchments especially the Njoro River catchment. Results obtained indicated that anthropogenic activities were the major contributing factors to the changes in Land Use Land Cover experienced in both catchments. We recommend continued analysis of the trends and rates of land cover conversions owing to their potential use by development planners. 


2011 ◽  
Vol 13 (5) ◽  
pp. 695-700
Author(s):  
Zhihua TANG ◽  
Xianlong ZHU ◽  
Cheng LI

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Aman Srivastava ◽  
Pennan Chinnasamy

AbstractThe present study, for the first time, examined land-use land cover (LULC), changes using GIS, between 2000 and 2018 for the IIT Bombay campus, India. Objective was to evaluate hydro-ecological balance inside campus by determining spatio-temporal disparity between hydrological parameters (rainfall-runoff processes), ecological components (forest, vegetation, lake, barren land), and anthropogenic stressors (urbanization and encroachments). High-resolution satellite imageries were generated for the campus using Google Earth Pro, by manual supervised classification method. Rainfall patterns were studied using secondary data sources, and surface runoff was estimated using SCS-CN method. Additionally, reconnaissance surveys, ground-truthing, and qualitative investigations were conducted to validate LULC changes and hydro-ecological stability. LULC of 2018 showed forest, having an area cover of 52%, as the most dominating land use followed by built-up (43%). Results indicated that the area under built-up increased by 40% and playground by 7%. Despite rapid construction activities, forest cover and Powai lake remained unaffected. This anomaly was attributed to the drastically declining barren land area (up to ~ 98%) encompassing additional construction activities. Sustainability of the campus was demonstrated with appropriate measures undertaken to mitigate negative consequences of unwarranted floods owing to the rise of 6% in the forest cover and a decline of 21% in water hyacinth cover over Powai lake. Due to this, surface runoff (~ 61% of the rainfall) was observed approximately consistent and being managed appropriately despite major alterations in the LULC. Study concluded that systematic campus design with effective implementation of green initiatives can maintain a hydro-ecological balance without distressing the environmental services.


2021 ◽  
Vol 10 (5) ◽  
pp. 272
Author(s):  
Auwalu Faisal Koko ◽  
Wu Yue ◽  
Ghali Abdullahi Abubakar ◽  
Akram Ahmed Noman Alabsi ◽  
Roknisadeh Hamed

Rapid urbanization in cities and urban centers has recently contributed to notable land use/land cover (LULC) changes, affecting both the climate and environment. Therefore, this study seeks to analyze changes in LULC and its spatiotemporal influence on the surface urban heat islands (UHI) in Abuja metropolis, Nigeria. To achieve this, we employed Multi-temporal Landsat data to monitor the study area’s LULC pattern and land surface temperature (LST) over the last 29 years. The study then analyzed the relationship between LULC, LST, and other vital spectral indices comprising NDVI and NDBI using correlation analysis. The results revealed a significant urban expansion with the transformation of 358.3 sq. km of natural surface into built-up areas. It further showed a considerable increase in the mean LST of Abuja metropolis from 30.65 °C in 1990 to 32.69 °C in 2019, with a notable increase of 2.53 °C between 2009 and 2019. The results also indicated an inverse relationship between LST and NDVI and a positive connection between LST and NDBI. This implies that urban expansion and vegetation decrease influences the development of surface UHI through increased LST. Therefore, the study’s findings will significantly help urban-planners and decision-makers implement sustainable land-use strategies and management for the city.


2012 ◽  
Vol 7 (No. 1) ◽  
pp. 10-17 ◽  
Author(s):  
S. Wijitkosum

Soil erosion has been considered as the primary cause of soil degradation since soil erosion leads to the loss of topsoil and soil organic matters which are essential for the growing of plants. Land use, which relates to land cover, is one of the influential factors that affect soil erosion. In this study, impacts of land use changes on soil erosion in Pa Deng sub-district, adjacent area of Kaeng Krachan National Park, Thailand, were investigated by applying remote sensing technique, geographical information system (GIS) and the Universal Soil Loss Equation (USLE). The study results revealed that land use changes in terms of area size and pattern influenced the soil erosion risk in Pa Deng in the 1990–2010 period. The area with smaller land cover obviously showed the high risk of soil erosion than the larger land cover did.


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