Lake Area Changes In Badain Juran Desert And Its Influence Factors Based On Remote Sensing Images

It is significant to master the dynamic process of the lake changes in the Badain Jaran Desert opportunely and accurately, for the exploration of the water cycling mechanism of the desert lake and the efficient use of the desert water resource. In this paper, Lake area information in the Badain Jaran Desert in1973,1990,1995,2000,2004,2010,2013,2014was gotten by the desert lake water index and visual interpretation of the Landsat remote sensing images. By building the datasets of the lake area information, we analyzed the spatial and temporal characteristics of lake area change on long time series scale (40years) and on a year scale. In addition, the meteorological datasets from two meteorological station in Alxa Right Banner and Yabrai, at the southern edge of the Badain Jaran Desert, are used to analyze the main influence factors of the lake area changes. From the studies, the main conclusions are as follows:(1) During1973to2013, the number and the area of the desert lakes are both have changed. The number and the area of desert lakes tended to be decreased, and the rate of reduction was from fast to slow, but not all the desert lakes shrank.(2) Lakes in Badan Jaran Desert hinterland show considerable variation within one year. The number and the area of desert lakes both reached the maximum in April, and drop down in summer and autumn, and then go up in winter and spring, till maximize again in April of the next year, as the same as the previous condition. The rate of lake change tends to be fast in spring and summer while it tends to be slow in autumn and winter; the shrink of lake area has a significant spatial autocorrelation relationship.(3) Human factors on the lake changes were quite little. In the long time scale, the main reason for the change of lake area is due to the decrease of underground water recharge, not the local climate change. Within a year, lake area change is impacted quite slightly by precipitation, and it is mainly affected by the water evaporation, especially on small lakes. Additionally, the lake area changes are affected by strong lake water evaporation in summer and autumn, while the recovery of lake area in winter and spring is largely due to groundwater recharge.(4) The DLWI water index, which was proposed by our research group, has a high accuracy in the progress of desert lake water extraction; so that it can be used to accurately extract the water (not including the ice surface) information of the desert lakes.