Differential interferometric synthetic aperture radar (SAR) (DInSAR) has proven to be very useful in mapping and monitoring land subsidence in many regions of the world. Shanghai, China's largest city, is one of such areas suffering from land subsidence as a result of severe withdrawal of groundwater for different usages. DInSAR application in Shanghai with the C-band European Remote Sensing 1 & 2 (ERS-1/2) SAR data has been difficult mainly due to the problem of decorrelation of InSAR pairs with temporal baselines larger than 10 months. To overcome the coherence loss of C-band InSAR data, we used eight L-band Japanese Earth Resource Satellite (JERS-1) SAR data acquired during 2 October 1992 to 15 July 1998 to study land subsidence phenomenon in Shanghai. Three of the images were used to produce two separate digital elevation models (DEMs) of the study area to remove topographic fringes from the interferograms used for subsidence mapping. Six interferograms were used to generate 2 different time series of deformation maps over Shanghai. The cumulative subsidence map generated from each of the time series is in agreement with the land subsidence measurements of Shanghai city from 1990 - 1998, produced from other survey methods.

A culvert is an important structure in Road construction to allow the conveyance of Channels crossing the road. Culverts are sized for a road to accommodate the volume of water crossing the road network to avoid flooding. Ghana Highways has a standard manual for culvert sizing at channel crossing. This manual serves as a guide for the proper sizing of culverts, however, lots of culverts have been found to have failed. Among the reasons for the failure of culverts could be under-sizing, urbanization, climate change, lack of maintenance, etc. The Daboya-Mankarigu Road is situated in the Savanah Region of Ghana in the North Gonja District. The section of the road from Chainage 9 + 075 to 10 + 200 has been experiencing flooding from 2020 to 2021 with a flood depth of 3.315 m in 2020 and 2.00 m in 2021. This study seeks to use integrated GIS and hydrological-based methods to propose new culverts to supplement the existing culverts to control flooding at section (9 + 075 to 10 + 200) of Daboya-Mankarigu Road (IR10). Geographic Information system (GIS) model (SWAT), Hydrological and hydraulic models were used to determine the peak flow at the catchment to Propose new culverts to supplement the existing culverts. Using a design period of 25 years for culverts, the modified rational method was used to determine the Peak flow of the catchment. A 25-year peak flow of 367.155 m³/s was determined and used for hydraulic analysis of the existing culverts. From the study, the existing culvert structures at the section had a hydraulic capacity of 78.732 m³/s which could not accommodate the remaining flow of 288.423 m³/s in the catchment. An observation was made that the changes in the rainfall can cause a change in rainfall intensity. An increase in built-up areas in the catchment can also increase the runoff coefficient which can result in higher peak flow in the catchment. Climate change, change in slope, and Land use in the catchment were also determined to have a huge influence on the adequacy of culverts since the peak flow is dependent on these parameters in the catchment as the years go by. A 4No. 4 m × 4 m box culvert, 3No. 3.5 m × 3.5 m box culvert, and 13 No. 1200 mm pipe culverts with 2 each at different chainages were proposed at suitable locations to supplement the existing culverts using the HDS-5 equations in AutoCAD Civil 3D. A recommendation is made to consider the installation of these new culverts at the flood section to control flooding and avoid overtopping of water on the IR10 road section (Daboya-Mankarigu) in the north Gonja District.

In this paper, authors have shown the capability of using InSAR techniques to map land subsidence phenomenon in both qualitative and quantitative terms. The problem of loss of coherence in Shanghai has also been assessed in this study with both the C-band ERS-1/2 and L-band JERS-1 SAR data. DInSAR qualitative analysis using JERS-1 differential interferograms revealed three stages of land subsidence in Shanghai from 1992 to 1998. The results indicated that the extent of land subsidence increased from 1992 through to 1998. It follows therefore that, activities taking place in the city might, in one way or the other, influence the progress of land subsidence in Shanghai as asserted by some researchers.Department of Land Surveying and Geo-InformaticsAuthor name used in this publication: Xiao-li Din

The World Health Organization (WHO) recognized Buruli ulcer (BU), a skin disease caused by Mycobacterium ulcerans (MU), as the third most prevalent mycobacterial disease in 1998, following tuberculosis and leprosy. In Ghana, there have been over 2000 reported cases in the past decade, with outbreaks in 90 administrative districts, including Amansie West. The mode of transmission remains unclear, but research suggests water bugs may be involved. This study aimed to assess this transmission method by identifying potential water bug habitats using geospatial techniques. Water bugs are found to inhabit freshwater ponds, marshes, slow-moving pools, streams, and mats of vegetation. This study used the Normalized Difference Water Index (NDWI) to locate water bodies and marshy areas, the Atmospherically Resistant Vegetation Index (ARVI) to identify vegetation zones, and Land Surface Temperature (LST) to determine suitable areas for water bugs based on temperature. A spatial multi-criteria evaluation (MCE) pinpointed critical areas for Mycobacterium ulcerans-hosting water bugs, which were mainly located in illegal mining areas due to stagnant wastewater. Notably, 36 communities, including prominent ones like Manso Nkwanta and Pakyi Number 1 and 2, were situated within these critical zones. This study generated a geospatial distribution map highlighting the potential areas for Mycobacterium ulcerans-hosting water bugs in the Amansie West district, crucial for Buruli ulcer transmission. The study recommended improved environmental sanitation in the affected areas to combat this water bug-related health issue.