The urban heat island (UHI) phenomenon is an important research topic in the scholarly community. There are only few research studies related to the UHI in the Seoul metropolitan area (SMA). Therefore, this study examined the impact of urbanization on the formation of UHI in the SMA as a geospatial study by using Landsat data from 1996, 2006, and 2017. For this purpose, we analyzed the relative variation of land surface temperature (LST) with changes of land use/land cover (LULC) rather than absolute values of LST using gradient, intensity, and directional analyses. It was observed that the impervious surface (IS) has expanded, and the UHI effect was more penetrating in the study area, with considerable loss of other LULC including green surfaces along with the rapid urbanization of the study area. In this study, we divided the IS into persistent IS (PIS) and newly added IS (NAIS). The spatial distribution of the IS, forest surface (FS), PIS, and NAIS was observed based on gradient zones (GZs). The results show that GZ1 recorded a difference of 6.0 °C when compared with the GZ109 in 2017. The results also show that the city center was warmer than the surrounding areas during the period of study. Results reveal that the mean LST has a strong significant positive relationship with a fraction of IS and PIS in 2006 and 2017. On other hand, the mean LST has a strong negative relationship with a fraction of FS and NAIS in the same time points. Relatively low temperatures were recorded in FS and NAIS in both time points. Further, it was proved that the local climate of the SMA and its surroundings had been affected by the UHI effect. Therefore, urban planners of the SMA should seriously consider the issue and plan to mitigate the effect by improving the green surfaces of the city. More greening-oriented concepts are recommended in both horizontal and vertical directions of the SMA, that can be used to control the negative impact associated with UHI. The overall outputs of the study could be used as a proxy indicator for the sustainability of the SMA and its surroundings.

This study examines spatial knowledge of the local community and the participatory resource mapping (PRM) approach to demarcate land boundaries in the eastern boundary of Wilpattu National Park, Sri Lanka. Sri Lanka has four types of major administrative boundaries, namely, provinces, districts, divisional secretariat divisions (DSD), and Grama Niladari (GN) divisions. The smallest community segments are clustered inside each GN division. The lack of proper demarcation of these smallest community segments, called ‘villages’, has been identified as a significant issue when implementing community development plans and applications in government and non-government projects. Thus, the deliverables of community-based projects become less effective. The objective of this study was to explore means of demarcating land boundaries, to separately identify small community segments using participatory GIS (PGIS) techniques. The study was conducted covering 12 GN divisions adjoining the eastern border of Wilpattu National Park (WNP). The methods used included PGIS interviews and group discussions with PRM steps. Overall, around 100 selected community members, spread across 12 GN divisions, were chosen to participate in the study. Community society meetings were conducted in each village, and essential topographic information in the area was collected with the knowledge of local society members and GIS tools. Later, this was digitized and verified to improve the presentation and accuracy of the results. As a result, the study could identify villages in each GN division, while generating more precise digital maps. Through this study, it can be confirmed that PGIS has remarkable potential in land use planning applications. The study further shows the potential of the application of PGIS in community-based projects and their deliverables to the community, and in enhancing community education on spatial thinking and planning, while facilitating community empowerment and innovation.

<p><strong>Abstract.</strong> Nowadays, mapping of agricultural crop canopy in different growing stages are vital data for crop field monitoring than field-based observations in large scale agricultural crop fields. By mapping agricultural crop canopy, it is very easy to analyse the status of an agricultural crop field by using different vegetation indices. Further, the data can be used to estimate the yield. These information are timely and reliable spatial information to the farmers and decision makers. Mapping of crop canopy in an agricultural crop field in different growing stages are very challenging using satellite imagery mainly due to the difficulty of recording with high cloud coverage. Also, the cost for satellite imagery are higher in proportion to the spatial resolution. It takes some time to order a satellite imagery and sometimes can’t cover some growing stages. This problem can be solved by using low cost RGB based UAV imageries which can be operated at low altitudes (below the clouds) which and when necessary. This study is therefore aimed at mapping of a maize crop canopy using RGB based UAV imageries. UAV flights at different growth stages were carried out with a high resolution RGB camera over a maize field in Ampara District, Sri Lanka. For accurate crop canopy mapping, very high-resolution multi-temporal ortho-mosaicked images were derived from UAV imageries using free and open source image processing platforms with spatial resolution in centimetre level. The resultant multi-temporal ortho-mosaicked images can be used to map and monitor the crop field’s precise and efficient manner. These information are very important for farmers and decision makers to properly manage the crop fields.</p>