一种基于八分位法的工业热污染区提取方法

Extraction Method of Industrial Heat Pollution Area based on Octave Method

针对工业热污染区提取准确率低、误差大及遗漏率高等问题,提出一种基于八分位法的工业热污染区提取方法。即首先基于改进的单通道算法获得地表温度,其次采用八分位法提取高温异常区,通过叠加建筑用地,得到疑似工业热污染区。然后,以彩钢房为判断标准,利用Google Earth影像进一步提取工业热污染区。通过对比分析热岛强度(HI)、改进的箱线图和八分位法3种方法的精度差异,发现潜在热异常是导致结果降低的主要因素。其中,热岛强度和改进的箱线图法均受到人类活动影响,提取的工业热污染区中居民区和商业区所占比例不小于工业区,误判率较高,八分位法提取精度最高,效果更佳,且从一定程度上避免了潜在热异常带来的影响。为验证结果精度,随机选取10%的工业热污染区像素点作为验证点,经Google Earth核实,发现利用八分位法提取的工业热污染区精度均在70%以上,最高可达92%。因此,八分位法提取工业热污染区简单有效,结果准确可靠,能够避免目标区内潜在热异常的影响,能够为环境保护、工业去产能监测提供技术支撑服务。

Aiming at the problems of low accuracy,large error and high omission rate in the extraction of industrial thermally polluted areas,an extraction method for industrial thermally polluted areas based on the octant method was proposed.That is,firstly,the surface temperature is obtained based on the improved single-channel algorithm,and then the high temperature anomalous area is extracted by the octet method,and the suspected industrial thermal pollution area is obtained by superimposing the building land.Then,using the color steel room as the criterion,Google Earth images were used to further extract the industrial heat-polluted areas.By comparing and analyzing the difference in accuracy of the three methods of Heat Island intensity(HI),improved boxplot,and octave method,it is found that the potential thermal anomaly is the main factor leading to the reduction of results.Among them,the intensity of the heat island and the improved box plot method are affected by human activities.The proportion of residential and commercial areas in the extracted industrial thermal pollution area is not less than that of the industrial area,and the false positive rate is high,The effect is better,and the impact of potential thermal anomalies is avoided to a certain extent.In order to verify the accuracy of the results,randomly selected 10%of industrial thermally polluted pixels were used as verification points.After verification by Google Earth,it was found that the accuracy of the industrial thermally polluted areas extracted by the octave method was more than 70%,up to 92%.Therefore,the octave method is simple and effective for extracting industrial thermally polluted areas,and the results are accurate and reliable.It can avoid the potential thermal anomalies in the target area,and can provide technical support services for environmental protection and industrial capacity reduction monitoring.