Research and Analysis on Refined Precipitation Forecast Method of Highway during Flood Season in Gansu Province

In this paper, T639 global spectral model numerical forecast products issued by numerical prediction center of China Meteorological Administration and precipitation data at 676 regional stations of Gansu during flood season were used firstly for interpretation. Then, through the establishment of multiple linear stepwise regression equation, daily precipitation forecast with the time interval of 6 h during 0 -72 h in May, 2013 in Gansu Province was obtained. By precipitation forecast verification analysis, it was found that the precipitation forecast in Hexi region and central Gansu Province had best effect; forecast in some places of east Hedong region had relatively good effect; part of the city or state forecast effect in the plateau slope zone was relatively lower. The refined precipitation forecast had certain reference and use value in the post-production Gansu Province highway forecasting during flood season.

Causes and Changes of Drought in China:Research Progress and Prospects

Drought is one of the most serious and extensive natural hazards in the world.Subject to monsoon climate variability,China is particularly influenced by drought hazards,especially meteorological drought.Based on a comprehensive understanding of the current status of international drought research,this paper systematically reviews the history and achievements of drought research in China since the founding of the People’s Republic of China,from four main perspectives:characteristics and spatiotemporal distribution of historical and recent drought events,drought formation mechanism and change trend,drought hazard risk,and the particular flash drought.The progress and problems of drought research in China are analyzed and future prospects are proposed,with emphasis on the multi-factor synergetic effect for drought formation;the effect of land-atmosphere interaction;identification,monitoring,and prediction of flash drought;categorization of drought and characteristics among various types of drought;the agricultural drought development;drought response to climate warming;and assessment of drought hazard risks.It is suggested that strengthening scientific experimental research on drought in China is imperative.The present review is conducive to strategic planning of drought research and application,and may facilitate further development of drought research in China.

Experimental Study of the Imbalance of Water Budget over the Loess Plateau of China

The imbalance of land-surface water budget was discovered in past studies, but there have been few further investigations on the relevant causes. To probe into the problem, annual variations of precipitation and land-surface evapotranspiration were analyzed by using the historical observation data from a compre- hensive land-surface observation base of LOPEX （Loess Plateau Experiment）. A remarkable imbalance in the land-surface water budget was found, and the total annual imbalance reached 20.6%. Then, the impact factors related to additional water budget components and observational methods were studied. The total annual imbalance could be reduced to 3.8% by using a combination of compensated land-surface water bud- get components and the surface evapotranspiration values obtained from the large-scale weighing lysimeter rather than from the eddy correlation method.