Conventional hydrological models erratically replicate slow hydrological dynamics, necessitating model modification and paradigm shift in hydrological science. The system dynamics approach successfully explains patterns of slow hydrological behaviors at inter-annual and decadal scales by dividing a hydrological system into different hierarchies and building endogenous linking structure among stocks. In spite of the simplicity, it holds potential to integrate hydrological behaviors across scales.

The hydrological processes of a watershed system are affected by both natural conditions, such as rainfall and drought, and human activities, such as deforestation and afforestation. Therefore different hydrological responses to climatic and anthropogenic changes are expected. Using a spectral approach, this study confirmed that the driving factors of water storage and streamflow generation mechanism vary over time. This is important for water resources management under changing world.

Quantifying the impact of upstream water use on downstream water scarcity is critical for water management. Comparing natural and observed runoff in China's 12 basins, this study found surface water use increased 1.6 times for the 1970s-2000s, driving most arid and semi-arid (ASA) basins into water scarcity status. The water stress decreased downstream in ASA basins due to reduced upstream inflow since the 2000s. Upstream water use caused over a 30 % increase in water scarcity in ASA basins.

The strong decadal variations in surface solar radiation, known as "global dimming and brightening", are considered to be related to anthropogenic activities. Based on a comprehensive set of sunshine duration measurements in China, the present study investigates to what extent these changes occurred, only in cities or also in remote areas. The quantification of this "urbanization effect" enables a more accurate determination of the large scale variations of surface solar radiation over China.