Perceived Status Of Ecosystem Services Emanating From A Forest Reserve: Evidence From Atewa Range Forest Reserve In Ghana.

Forest ecosystem services play an integral part in the realization of global sustainable development goals due to their potential contribution to climate change mitigation and forest-based livelihoods in marginalized rural parts of the world. The Atewa Forest Range Reserve has been recognized to support forest-based livelihoods in adjacent communities and even urban areas of Ghana. While this contribution is acknowledged, information on the current status of the reserve's ecosystem services which are under serious threats from human-induced activities, remains fragmented. Therefore, through a household survey of 150 respondents complemented by key informant interviews (n = 9), this research assessed the awareness and perceptions of people on the current status of the Atewa Forest Range Reserve and its ecosystem services as well as the major drivers of change that seem to threaten the provision of these ecosystem services. Our results point to provisioning services as the most widely utilized ecosystem service, leading to their significant decline with the potential to affect the livelihoods of the local populations. Respondents' awareness and the relative importance they ascribe to the reserve's ecosystem services reinforced their appreciation for these services and interest in their sustainable management. Our results suggest the need for understanding local perceptions of ecosystem services to guide the prioritization of management decisions for balancing both utilization and conservation goals. A co-management approach that fosters the strategic inclusion of local communities in decision-making regarding the forest reserve could contribute to collaborative relationships and further increase positive perceptions of locals to preserve the reserve's ecological functions.

Urbanization and flood risk analysis using geospatial techniques.

This research investigates the relationship between urbanization as a land use/land cover change and the increased flood disasters in Accra. Understanding this relationship will provide evidence for urban development planners, policy makers and flood managers to coordinate in responding to the problems effectively. This study maps and analyzes the changes in urbanization from 1991 to 2015. The research reviews the trends of flood events in Greater Accra and analyzes the relationship between the pattern of urbanization and the increase in flood disaster events from 1991 to 2015. The research revealed that there was an increase in urban land use/land cover change of up to 95.51% and 129.14% in the periods 1991-2002 and 2002-2015 respectively. The pattern of urbanization took place in an unplanned style, where physical developments in waterways became high. The findings show that the pattern of flood disasters increased from 1991 to 2015 with evidence showing two years having repeated flood events.

Geospatial analysis of flood emergency evacuation sites in Accra.

Cities face frequent flood disasters with devastating impact on lives and property. Geospatial analysis using high elevation points can help to map out emergency evacuation centres for decision making on flood risk management. This research maps and analyses flood emergency evacuation centres in Accra. The objectives of this research were to map out flood hazard and vulnerable settlements, analyse the spatial distribution and identify the optimal locations for flood emergency evacuation sites. The data for this study comprises digital elevation models, stream networks, settlement data, flood risk zone maps of the study site and existing documents on flood disaster risk of the study area. This study adopted the weighted linear combination method to estimate site suitability for emergency evacuation sites. ArcGIS 10.6 was used to analyse the data. The research found that the optimal locations for potential evacuation centres are unevenly distributed between 300 m and 400 m above sea level, most which are in the north-eastern and north-western parts of Accra. The results can contribute to research, policy and decision-making on flood risk management in Accra and other localities with similar conditions. The research further contributes to literature on flood risk management and geographic information system. Contribution: This research is useful as mapping could increase awareness of evacuation sites to speed up rapid response to immediate impacts of flood events. The findings of the study will facilitate future decisions for demarcating potential flood emergency evacuation sites. The overall aim of this study is to contribute to literature, policy, spatial analysis and the practice of flood risk management in the study area. The research findings can also be applied to other flood-prone areas with similar contexts as the study site.

Framework of multi-level regionalization schemes based on non-point source pollution to advance the environmental management of small watersheds.

Regionalization exerts an important guiding role for sound environmental management, regional development, and schemes toward regionalizing ecological function, involving multiple levels. This paper formulated a framework for a detailed regionalization approach using the Ashi River watershed, China, as case study. Human activities, especially agriculture non-point source pollution (ANPS) and social factors, were identified as main factors. The results indicated that (1) the export coefficient model (ECM) can be used to determine ANPS loads in the watershed as well as total nitrogen and total phosphorus loads. (2) The minimum cumulative resistance model (MCR) showed that the middle and lower reaches had high risk for ANPS occurrence. (3) Based on the identified key factors, the watershed was divided into level IV and combined with existing level III using cluster analysis. Corresponding management countermeasures were proposed. This provides a scientific basis for pollution control planning and for management measures.

Evidence and impact of map error on land use and land cover dynamics in Ashi River watershed using intensity analysis.

Previously, applications of intensity analysis (IA) on land use and land cover change (LULCC) studies have focused on deviations from uniform intensity (UI) and failed to quantify the reasons behind these deviations. This study presents the application of IA with hypothetical errors that could explain non-uniform LULCC in the context of IA at four-time points. LULCC in the Ashi watershed was examined using Landsat images from 1990, 2000, 2010 and 2014 showing the classes: Urban, water, agriculture, close canopy, open canopy and other vegetation. Matrices were created to statistically examine LULCC using IA. The results reveal that the seeming LULCC intensities are not uniform with respect to the interval, category and transition levels of IA. Error analysis indicates that, hypothetical errors in 13%, 19% and 11.2% of the 2000, 2010 and 2014 maps respectively could account for all differences between the observed gain intensities and the UI; while errors in 12%, 21%, and 11% of the 1990, 2000 and 2010 maps respectively could account for all differences between the observed loss intensities and the UI. A hypothetical error in 0.6% and 1.6% of the 1990 map; 1.5% and 4% of the 2000 map; 1.2% and 2.1% of the 2010 map could explain divergences from uniform transitions given URB gain and AGR gain during 1990-2000, 2000-2010 and 2010-2014 respectively. Evidence for a specific deviation from the relevant hypothesized UI is either strong or weak depending on the size of these errors. We recommend that users of IA concept consider assessing their map errors, since limited ground information on past time point data exist. These errors will indicate strength of evidence for deviations and reveals patterns that increase researcher's insight on LULCC processes.

Mechanisms and reutilization of modified biochar used for removal of heavy metals from wastewater: A review.

Heavy metals (HMs) pose serious threat to both human and environmental health and therefore, effective and low-cost techniques to remove HMs are urgently required. Because HMs are difficult to be biodegraded and transformed, adsorption is a most promising treatment method in recent times. Biochar (BC), a low-cost and sustainable adsorbent material, has recently attracted much research attention due to its broad application prospects. While BC has many merits, it has a lower HMs adsorption efficiency than traditional activated carbon, limiting its practical applications. Furthermore, the HMs retained by BC are difficult to be desorbed, making the used sorbent material hazardous wastes if not well disposed of under natural conditions. Therefore, it is critical to seek effective surface modifications for BC, to improve its ability to HMs removal ability and the recyclability of BC loaded with HMs. This review represents and evaluates the reported modification methods for BC, the corresponding HMs removal mechanisms and the potential for reutilization of BC loaded with HMs. This review provides a basis for the effective practical application of BC in the treatment of HMs containing wastewater.