With the development of geographic information processing platform based on cloud computing, free and fast processing of massive remote sensing data has become possible. Prof. Niu Zheng’s Team of the “Digital Belt and Road Research Project” of CASEarth carried out ecological environmental monitoring using cloud computing resources and recently, the team completed the monitoring of the surviving environment of Tibetan antelope with massive remote sensing imagery.
Researchers found that, although the number of Tibetan antelope individuals has recovered significantly to more than 200,000 in 2016 under strict protection measures since the 1990s, Tibetan antelopes are still faced with an existential threat from climate change. Tens of thousands of Tibetan antelopes travel hundreds of kilometers to lamb at Zhuonai Lake every summer. However, affected by the warming and humidifying climate on the Qinghai-Tibet Plateau, the precipitation in Hoh Xil has been increasing for nearly half a century. Besides, Zhuonai Lake had a rapid rise in water levels after the heavy rains in August 2011 and had a levee breach in mid-September, which caused flooding and massive overflow of lake water. The new riverbed formed by flooding blocked the migration route of Tibetan antelopes from the “Three-River Headwaters” Region to the south shore of Zhuonai Lake for lambing.
The team has monitored the conservation of wildlife on the Qinghai-Tibet Plateau for a long time. They collected and processed images of 30-meter resolution US terrestrial satellites (Landsat TM/ETM+/OLI) from June to July each year (2008-2014) before and after the levee breach of Zhuonai Lake, and analyzed the changes in the water area before and after such levee breach.
The results show that the lake area decreased by more than 40% after the levee breach. The substantial shrinking of lake shoreline of Zhuonai Lake and serious land desertification have directly led to the deterioration of the habitat of Tibetan antelopes and the increase of drinking distance. This study also used the activity point data of Tibetan antelopes in the same period which clearly demonstrated the impacts of levee breach of Zhuonai Lake on the population activity of Tibetan antelopes. According to researchers, after levee breach of Zhuonai Lake, some Tibetan antelopes began to lamb around Kusai Lake in the lower reaches of Zhuonai Lake. According to relevant existing studies, changes in migration routes and lambing places are likely to adversely affect the reproduction of the Tibetan antelope population. Besides, after the levee breach of Zhuonai Lake, a large amount of water flowed into the lower reaches of Haidingnuoer Lake and the salt lake. Some scholars predict that the salt lake will overflow in the next 1-2 years. Its water with a high concentration of salt may further damage the grassland ecosystem on which Tibetan antelopes live in Hoh Xil.
This researchwas published in the journal Science. This study is a typical application of BigEarth Data in the field of animal protection and ecological environment monitoring. The findings can effectively serve scientific decision-making.
Comparison of Landsat Satellite Composite Images before (2008-2011) and after (2012-2014) Levee Breach of Zhuonai Lake