Downscaling Precipitation in the Data-Scarce Inland River Basin of Northwest China Based on Earth System Data Products
Downscaling Precipitation in the Data-Scarce Inland River Basin of Northwest China Based on Earth System Data Products
复制标题
基于地球系统数据产品的西北数据稀缺内陆河流域降水降尺度
DOI：
10.3390/atmos10100613
复制
发表时间：
2019
期刊：
影响因子：
2.9
通讯作者：
Wang Chong
中科院分区：
文献类型：
--
作者：
Zuo Jingping;Xu Jianhua;Chen Yaning;Wang Chong
Precipitation is a key climatic variable that connects the processes of atmosphere and land surface, and it plays a leading role in the water cycle. However, the vast area of Northwest China, its complex geographical environment, and its scarce observation data make it difficult to deeply understand the temporal and spatial variation of precipitation. This paper establishes a statistical downscaling model to downscale the monthly precipitation in the inland river basin of Northwest China with the Tarim River Basin (TRB) as a typical representation. This method combines polynomial regression and machine learning, and it uses the batch gradient descent (BGD) algorithm to train the regression model. We downscale the monthly precipitation and obtain a dataset from January 2001 to December 2017 with a spatial resolution of 1 km × 1 km. The results show that the downscaling model presents a good performance in precipitation simulation with a high resolution, and it is more effective than ordinary polynomial regression. We also investigate the temporal and spatial variations of precipitation in the TRB based on the downscaling dataset. Analyses illustrate that the annual precipitation in the southern foothills of the Tianshan Mountains and the North Kunlun Mountains showed a significant upward trend during the study periods, while the annual precipitation in the central plains presented a significant downward trend.
