Chen Z.,Wuhan Institute of Heavy Rain |
Chen Z.,Wuhan Region Climate Center
Wuhan Ligong Daxue Xuebao (Jiaotong Kexue Yu Gongcheng Ban)/Journal of Wuhan University of Technology (Transportation Science and Engineering) | Year: 2010
Using the yearly series of maximum 10 min averaged wind velocity observed by Yuyang weather stations from 1952 to 2000, the gale characteristics of Yuyang weather stations was analyzed. The reference wind velocity and design wind velocity were calculated by adopting the function of Extreme I and referencing the observed wind datum along Yangtze River nearby bridge location. Several conclusions are listed as following: (1) the bridge location takes EN wind as dominant wind direction and extreme value of maximum 10 min wind velocity is 24.7 m/s. (2) The annually averaged maximum 10 min wind velocity of the 10 meter high for different return periods(100, 50, 30, 10 year) are respectively 27.6 m/s, 25.4 m/s, 23.8 m/s and 20.2 m/s. (3) the averaged maximum 10 min wind velocity of the 10 meter high of bridge location for different return periods(100, 50, 30, 10 year) are respectively 29.0 m/s, 26.7 m/s, 25.0 m/s and 21.2 m/s. Finally, the design reference wind speed of every 10 m layer within 300 m high is extrapolated by using the index change of wind velocity in the surface layer changed by the height, which can be referred for design and construction of the bridge.
Liu K.,Wuhan Region Climate Center |
Liang Y.,Wuhan Region Climate Center |
Zhou J.,Wuhan Central Meteorological Observatory |
Liu M.,Wuhan Region Climate Center
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2014
In recent years, drought events in Honghu lake have shown a significant increasing trend, which has had a tremendous impact on local ecological and agricultural production. We conducted an analysis based on Honghu's hydrology and land-use data over the past 30 years and climate data from 1960 to 2011, using the water balance principle and statistical methods. The results showed that the Honghu water resource is most vulnerable in the spring. The water level at this time of year is just slightly higher-with 2 to 3 times the mean standard error-than that in winter, which leads to frequent and severe drought in Honghu. With global climate change, however, the local annual precipitation is increasing; the rainfall is concentrated in summer and is less in spring, especially in spring drought years, with a decreasing rate of 12.57 mm/ 10a, significant at 0.1. The precipitation in summer increases, but it is negatively correlated with the water level in the following spring, which means that an increase in precipitation in summer can aggravate the severity of the spring drought. The Honghu lake water level in May is highly dependent on spring rainfall, with a rate of 0.36 m/ 100 mm. Over the past 20 years, the agricultural structure in Honghu has changed significantly, with increasing aquaculture areas and decreasing dry crop areas. The aquaculture area of the two counties surrounding Honghu has increased nearly 7 times and, because of this, the agricultural irrigation water requirement has increased by more than 414 million cubic meters in the case of low rainfall, which is equivalent to 45% of the total water in Honghu lake's annual income. Increasing aquaculture consumes much of the water resource in spring and the coefficient between aquaculture and water level of Honghu is about -0.158 m/ 104 hm2 with a correlation coefficient of - 0. 4954, which is significant at 0. 1. Human activities, especially excessive aquaculture and climate change, are the main reason for the increasing frequency and severity of spring drought in Honghu, with aquaculture having the greatest impact. In order to maintain Honghu's ecological function and reduce the drought effects, measures should be taken to change both the agricultural structure and the way in which land is used.
Liu K.-Q.,Wuhan Region Climate Center |
Liang Y.-T.,Wuhan Region Climate Center |
Zhou J.-L.,Wuhan Center Station of Meteorology |
Liu M.,Wuhan Region Climate Center
Proceedings of the 2013 3rd International Conference on Intelligent System Design and Engineering Applications, ISDEA 2013 | Year: 2013
With the global climate change, the increasing economic activity and excessive development in recent years, the climate ecological environment of Honghu Lake changes with frequent occurrence, sharp reversal of flood and drought and the atrophy of the natural lake, which lead to loss or degradation of partial functions of the lake. How to rationally develop and protect the lake and its surrounding land resources has become a very urgent task. According to the climate data and the hydrological data in Honghu area in recent 50 years, land use change in recent years, effect on water level and utilizable precipitation because of different land use and the change characteristics of precipitation and drought of Honghu were analyzed. Analyses show that the precipitation increased in Honghu region in recent 50years, especially the heavy precipitation, so that the proportion of heavy rain to total precipitation and the concentration degree of heavy precipitation increase, which lead to increase of flood. With the increase of economic activity, land use changed greatly. Farmland area decreases and aquaculture area increased 6-7 times nearly 20years. Aquiculture area of three surrounding counties equals to 2-3 Honghu Lake area in 2010. Agriculture and fishery need great deal of water from April to May, which is the main reason for more disasters in drought year and ecological functions destruction of Honghu wetlands. © 2012 IEEE.