基于移动设备的电子草图软件的设计与实现

针对目前大比例尺数字测图中传统草图法、简码法和电子平板法存在诸多不便的问题,提出了将传统草图法和简码法相结合的电子草图法,介绍了基于电子移动设备的电子草图软件的设计与实现,并以近年发展迅速的安卓平台为例,阐述了电子草图软件在实现过程中的关键问题。     

Remote sensing-based geostatistical hot spot analysis of Urban Heat Islands in Dhaka,Bangladesh

Urban Heat Island (UHI) refers to a phenomenon whereby urban areas experience higher temperatures compared to the surrounding areas. Remote sensing-based Land Surface Temperature (LST) measurements can be utilized to measure UHI. This study emphasized on geostatistical remote sensing-based hot spot analysis ($G_i^{*}$) of UHI in Dhaka, Bangladesh as a way of examining the influences of Land Use Land Cover (LULC) on UHI from 1991 to 2015. Landsat 5 and 7 satellite-based remote sensing indices were used to explore LULC, UHI and environmental footprints during the study period. The Urban Compactness Ratio (C_oR) was used to calculate the urban form and augmented characteristics. The Surface Urban Heat Island (SUHI) intensity (ΔT) was also used to explore the effects of UHI on the surrounding marginal area. Based on our investigations into LULC, we discovered that around 71.34 per cent of water bodies and 71.82 percent of vegetation cover decreased from 1991 to 2015 in Dhaka city. Contrastingly, according to C_oR readings, 174.13 km² of urban areas expanded by 249.77 per cent. Our hot spot analysis also revealed that there was a 93.73 per cent increase in hot concentration zones. Furthermore, the average temperature of the study area had increased by 3.26°C. We hope that the methods and results of this study can contribute to further research on urban climate.