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青藏高原湖泊面积变化在反映气候变化方面具有非常重要的意义。通常的阈值法提取湖泊面积由于受到冻湖、山体阴影和冰雪的影响,进行大范围提取时会存在阈值选择的不确定性和较难实现自动化提取等问题。基于归一化差异水体指数NDWI(Normalized Difference Water Index)、数字高程数据和雪盖指数NDSI(Normalized Difference Snow Index),提出了针对冻湖的湖泊面积插补迭代自动提取方法。结果表明,此方法能够实现非冻湖和冻湖阈值的自动确定,不仅可以在大范围内准确地完成湖泊面积提取,而且能减少山体阴影、冰雪的干扰。该方法相较于传统的基于水体指数的阈值法,具有更高的分类精度。
The change of lake area in the Qinghai-Tibet Plateau is very important in reflecting the climate change. The usual threshold method to extract the lake area due to the impact of frozen lake, mountain shadow and ice and snow, there will be the uncertainty of the threshold selection and difficult to automate the extraction of large-scale extraction problems. Based on Normalized Difference Water Index (NDWI), Digital Elevation Data (NDWI) and NDSI (Normalized Difference Snow Index), an automatic interpolation method of lake area interpolation for frozen lake was proposed. The results show that this method can automatically determine the threshold of frozen lake and frozen lake, which not only can accurately extract the lake area in a wide range, but also can reduce the shadow of the mountain and the interference of snow and ice. Compared with the traditional threshold method based on water body index, this method has higher classification accuracy.