Glacier Change In Geladandong Region Based On CART Decision Tree Method

Glaciers are considered to be the most sensitive indicator and storage of climate change and are also closely related to climate change,water resources,sea level rise and glacial disasters.Therefore,the monitoring of glacier change information has important scientific and practical significance.In recent decades,global warming has caused large areas of glaciers in our country and even in the world to retreat,which has a direct impact on the change of runoff from glaciers supplying rivers.The study of glacial change has also evolved from traditional single direct observations to multiple data sources and multiple indirect observations.The development of 3S technology has provided strong support for glaciology research and can help us to effectively extract glacial change information,thus revealing the law of glacial change.The glaciers in the western part of China belong to the mountain glaciers in the middle and low latitudes.The mountain glaciers in the middle and low latitudes have strong sensitivity to the climate and have high research value.The article research area is Geladandong glacier.The paper uses remote sensing imagery,DEM data,meteorological data,and glacial cataloging data to extract glaciers in the Geladandong area using the CART decision tree method.The visual interpretation method is used to correct the extraction result and improve the extraction accuracy.Through research and analysis,the following conclusions have been drawn:(1)Glacial area of Geladandong in 1992,2002,2009,and 2015 was 918.16km2,896.43km2,870.78km2,and 839.19km2,respectively.(2)According to the area of the patch,each Geladandong is 0-0.2km2,0.2-0.5km2,0.5-1km2,and the area of glaciers larger than 1km2 in the four-level glaciers is more than 1km2,accounting for 99%of the total area of the remaining grades.1%.(3)According to the gradient,it is divided into four gradient grades:0-15°,15-25°,25-35°,and 35°.The largest glacier area is 0-15° accounting for 58.95%of the glacier area in the study area.(4)From an altitude point of view,the most widely distributed elevation range of the glacier is 5,600-5,800 m,and the smallest distribution area is 5,200-5,400 m.The distribution area gradually increases from 5,200-5,800 m and gradually decreases from 5800 to 6600.(5)From the aspect of orientation,the most glaciers are the shady slopes,followed by the shady slopes and the semi-sunny slopes.The sun slope with the smallest area of distribution.(6)From the length of a typical glacier,the largest retreat is the 5Z221H001 glacier,and the smallest retreat is 5Z213B0001.(7)Comparisons between the changes in the glacial area of Geladandong and other glaciers in western China have found that the variation of the Geladandong glacier is smaller than that of the Qilian Mountains and Tianshan Mountains,and is greater than Nyainqentanglha Mountain and the Pamirs Plateau.(8)According to the analysis of meteorological data,the temperature in the glacier area of Geladandong;area is continuously rising,and the precipitation is becoming larger,but the area of the glaciers is decreasing.