Determination of Transport Pathways and Mutual Exchanges of Atmospheric Moisture between Source Regions of Yangtze and Yellow River Basins

Knowledge of the quantitative importance of the moisture transport pathways and mutual moisture exchange of the source regions of the Yangtze (SYZR) and Yellow (SYR) rivers’ basins, the adjacent origins of China’s two longest rivers, can provide insights into the regional atmospheric branch of the hydrological cycle over the source regions. The method with the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model and a Lagrangian moisture source diagnostic to identify the major moisture transport pathways quantifies their importance to two types of daily precipitation events—daily precipitation more than 10 mm (PM) events and daily precipitation less than 10 mm (PL) events—for the two rivers’ regions during the summer (June–August, 1986–2015) and finds the characteristics of mutual moisture exchange. The results indicated that both the Bay of Bengal group pathway and the northwest China group pathway play significant roles in PM and PL events over the SYZR, contributing 41.87% and 39.12% to PM events and 41.33% and 33.16% to PL events, respectively. The SYR has five main moisture path groups; the Bay of Bengal group pathway, the northwest China group pathway, and the southeast China group pathway play significant roles in PM and PL events over the SYR, contributing 32.34%, 23.28%, and 34.36% to PM events and 34.84%, 36.18%, and 19.83% to PL events, respectively. The volume of moisture passing from the SYZR to the SYR is approximately 60 times that of the reverse, constituting about 6.9% of the total moisture released in SYR precipitation. It is worth noting that the moisture release was concentrated in the nearer west group pathway, and the main moisture uptake locations were beyond the source region of the two rivers (remote sources) in the PM events. The aggregate moisture release high-frequency moisture transport path groups are found in the southeastern parts of Zhiduo County and the southeast of Zaduo County

Research On Technological Utilizing in an Automatic Device for Collecting Rain and Snow in Qinghai Province, China

Based on the climatic conditions in the northwest and the widely used water storage method in the northwest rural areas, we designed a rain and snow collection device, which is realized by an inductor and an “M” collection curtain, which uses the rotation of the motor and the supply of the heating film. Water purification and storage can be obtained through compound grit tanks, biochar adsorption systems, etc. The collected water resources can be integrated with water purification and storage through flood control and antifreeze devices. Real-time senses the changes of water level and water temperature. In this article, a calculation model for the optimal sedimentation effect is also established, which can calculate the minimum scale parameters of the sedimentation tank under different weather conditions, and provide guidance for the construction of the system. In addition, we tested the actual collection capacity of the system, and the results showed that the system has high practical value. At present, there is no a complete and systematic study integrated with it in the Northwest region. This system can alleviate the lack of water resources in some areas to a certain extent, play a positive role in the rural ecological environment and lessen floo

Coordination control of hybrid AC/DC microgrid

The hybrid AC/DC microgrid is considered to be the more and more popular in power systems as increasing DC loads. In this study, it is presented that a hybrid AC/DC microgrid is modelled with some renewable energy sources (e.g. solar energy, wind energy), typical storage facilities (e.g. batteries), and AC, DC load, and also the power could be transformed smoothly between the AC and DC sub-grids by the bidirectional AC/DC converter. Meanwhile, coordination control strategies are proposed for power balance under various operations. In grid-connected mode, the U–Q (DC bus voltage and reactive) or PQ method is adopted for the bidirectional AC/DC converter according to the amount of exchange power between AC and DC system in order to improve the DG utilisation efficiency, protecting the converter and maintain the stable operation of the system. In islanded mode, V/F control is applied to stabilising the entire system voltage and frequency, achieving the power balance between the AC and DC systems. Finally, these control strategies are verified by simulation with the results showing that the control scheme would maintain stable operation of the hybrid AC/DC microgrid