Spatiotemporal variations of soil moisture in the Tarim River basin, China

- Long-term ECV soil moisture product is validated using in situ data in the Tarim River basin, China.
- Soil moisture relations with precipitation and temperature are analyzed.
- The ECV data captures the large scale dynamics of regional water cycle.
- Precipitation is more important factor than temperature controlling soil moisture.

Based on in situ soil moisture and river runoff records in the Tarim River basin, usability of the long term Essential Climate Variable (ECV) soil moisture dataset is validated in the arid climatic region of China. The spatio-temporal variation of soil moisture and its possible influencing factors in the 1988-2013 is also preliminary analyzed in the current paper. Results reveal that the ECV soil moisture can capture the large scale dynamics of regional water cycle quite satisfactorily, showing good agreement with in situ observations in their seasonal and interannual variability. In the period of 1988-2013, the ECV soil moisture shows obvious increasing trends in the northwest and the southwest parts of the Tarim River basin, particularly in spring (March-May) and autumn (September-November). Statistical analysis further suggests that the variations of soil moisture in the Tarim River basin are more controlled by precipitation, and temperature is less effective in controlling of soil moisture variations.