Title: Projected changes in wind speed and its energy potential in China using a high‐resolution regional climate model
Journal: Wind Energy
Abstract: Following its commitment to Paris Agreement in 2015, China has started to explore potential renewable energy solutions with low carbon emissions to mitigate global warming. Though wind energy is one of the most cost‐effective solutions and has been favored for climate policy development around the world, its high sensitivity to climate change raises some critical issues for the long‐term effectiveness in providing sustainable energy supply. Particularly, how wind speed and its energy potential in China will change in the context of global warming is still not well understood. In this paper, we simulate the near‐surface wind speed over China using the PRECIS regional climate modeling system under different RCP emission scenarios for assessing the possible changes in wind speed and wind energy availability over China throughout the 21st century. Overall, the PRECIS model can reasonably reproduce the mesoscale climatological near‐surface wind speed and directions as documented in reanalysis data across most regions of China, while some local discrepancies are reported in the southwestern regions. In the future, the annual mean wind speed would be decreasing in most regions of China, except for a slightly increase in the southeast. The expected changes in wind speed are characterized with different amplitudes and rates under different RCP emission scenarios. The changes in the spatial distribution of wind speed seem to be sensitive for RCP climate emission scenarios, especially in the late 21st century. The spatiotemporal changes in wind energy potential exhibit a similar behavior to those in near‐surface wind speed, but the magnitudes of these changes are larger. In general, the wind power density is expected to increase by over 5% in winter in the major wind fields in China (ie, Northwest, Northcentral and Northeast), while significant decreases (by about 6% on average) are projected for other seasons (ie, spring, summer and autumn). By contrast, the wind energy potential in the northeast would increase over most months in the year, especially in winter and summer. The results of this research are of great importance for understanding where and to what extent the wind energy can be utilized to contribute renewable energy system development in China in support of its long‐term climate change mitigation commitment.
The following paper about the projected changes in wind speed and its energy potential in China has recently been accepted for publication by Wind Energy:
Guo, J., G. Huang, X. Wang, Q. Lin, and Y. Li. Projected changes in wind speed and its energy potential in China using a high-resolution regional climate model. Wind Energy, accepted on August 21, 2019.
More details will come soon once the paper is published.
Title: Urban flood prediction under heavy precipitation
Journal: Journal of Hydrology
Abstract: Increasing city resilience to floods under climate change has become one of the major challenges for decision makers, urban planners, and engineering practitioners around the world. Accurate prediction of urban floods under heavy precipitation is critically important to address such a challenge as it can help understand the vulnerability of a city to future climate change and simulate the effectiveness of various sustainable engineering techniques in reducing urban flooding risks in real urban settings. Here, we propose a new model for urban flood prediction under heavy precipitation. The model divides an irregular urban area into many grid cells with no limitation on the spatial resolution as long as the DEM data of the same resolution are available. It is capable of reflecting the frequent inflow or outflow interactions among grid cells and capturing the rapid generation of surface runoff in urban areas during heavy rainfall. The model also accounts for typical characteristics of urban areas, such as large-scale impermeable surfaces and urban drainage systems, in order to simulate urban floods more realistically. In addition, the model uses both surface elevation and instantaneous surface water depth of all grid cells to dynamically determine the directions of horizontal inflow and outflow during each time step of model simulation. This enables the model to capture the reverse-flow phenomenon which is commonly seen in flat urban areas during heavy storms. By applying the proposed model for reproducing the 2016 flood in Lafayette Parish, Louisiana, we demonstrate its effectiveness in predicting real-world flood events.
Title: Projected changes in temperature, precipitation, and their extremes over China through the RegCM
Journal: Climate Dynamics
Abstract: As the second biggest economy in the world, China has been experiencing significant impacts of global climate change. Developing future projections of regional climate over China is an indispensable step for designing appropriate mitigation and adaptation strategies against future climate change. To this end, this study focuses on exploring how the regional climate over China, including the mean and extreme climate, will be affected in the context of global warming throughout this century. The RegCM model is used to develop high-resolution climate scenarios for the whole country of China driven by boundary conditions of the Geophysical Fluid Dynamics Laboratory (GFDL) model under the Representative Concentration Pathways (RCPs). RegCM performance on simulating the present climate over China is evaluated and the results indicate that it is capable of reproducing the spatial distributions of temperature and precipitation. Future projections from RegCM suggest that an increase of 2 °C in daily mean temperature is expected in China by the end of the twenty-first century under RCP4.5 while an increase of 4 °C would be seen under RCP8.5. The Tibetan Plateau is likely to expect the most substantial temperature increase as well as the most significant decrease in extreme cold climate in China. In comparison, the annual total precipitation over China is projected to increase by 58 mm/year at the end of the twenty-first century under RCP4.5 and by 71 mm/year under RCP8.5. The projected changes in precipitation show apparent spatial variability due to the influences of local topography and land cover/use.
The following paper about a new model for urban flood prediction under heavy precipitation has recently been accepted for publication by Journal of Hydrology:
Wang, X., G. Kinsland, D. Poudel, and A. Fenech. Urban Flood Prediction Under Heavy Precipitation. Journal of Hydrology, accepted on July 24, 2019.
More details will come soon once the paper is published.