Funding for this research was provided by:
the High-Tech Research and Development Program of China (2013AA122801)
the Natural Science Fund of China (41205104)
the Natural Science Fund of China (41201331)
the National Basic Research Program of China (2012CB955302)
the Fundamental Research Funds for the Central Universities (2012LYB38)
the High Resolution Earth Observation Systems of National Science and Technology Major Projects (05-Y30B02-9001-13/15-9)
the youth talent support program of College of Global Change and Earth System Science (312231103)