基于遥感技术北方城市热岛效应变化定量识别

以城市人口迅速增长和城市用地迅速扩张为显著特征，随着城市化进程快速推进，城市热岛效应也愈 加显著。为快速提取城市地表温度信息，以探究城市热岛效应的时空分布，基于中等分辨率常规易得的 2000-2018时段内Landsat 影像热红外波段的辐射信息，定位于热岛效应显著的北方典型城市长春市，采用单 窗算法，分别对不同年份的影像进行地表温度计算，并生成长春市地表温度专题图。以此为基础，结合相应 时段内的地面观测温度数据识别长春市热岛效应时空变化，探究典型区内热岛效应强度变化规律和影响因 素。结果表明，研究时段内长春市热岛效应的时序变化特征表现为夜晚较白天强，秋冬较春夏强; 空间变化 表现出明显的空间差异性，但整体上为温度高值区增加; 土地类型的热岛效应强弱关系: 建筑用地＞ 绿地＞ 林地＞ 水体。

Energy-Efficient Routing Protocol for Underwater Acoustic Sensor Networks

Characterized by rapid urban population growth and rapid expansion of urban land use，the urban heat island effect is becoming more and more significant． To quickly extract urban surface temperature information and explore the spatial and temporal distribution of urban heat island effect，based on the medium-resolution conventional and easily available radiation information of Landsat images in 2000-2018，the Changchun，a typical northern city with a significant heat island effect is taken as example to be explored． Using the single window algorithm to calculate the surface temperature of the images in different years and generate the thematic map of Changchun surface temperature． The experiment is combined with the ground observation temperature data in the corresponding period to identify the temporal-spatial changes of the heat island effect in Changchun and to explore the regular of change and influence factors of the intensity of the heat island effect in typical areas． The results show that the temporal change characteristics of the heat island effect in Changchun during the study period are strong at night and weak by day; strong in autumn and winter，while weak in spring and summer． Spatial variation show obvious spatial differences． But a whole， the high temperature zone increases． The relationship between the heat island effect of the land type: Building land ＞ Green land ＞ Forest land ＞Water body．