The Variation Rule and Anomaly Features of the Available Precipitation in the Growth Period of Crops in the Middle and Southern Part of Ningxia

[ Objective] The aim was to study the available precipitation and its abnormal characteristics during the growth period of crops in the mid- dle and southern part of Ningxia. [ Methed] Through Takahashi＇s evaporation equation, linear trend analysis, Mann -Kendall, Lepage, wavelet analysis, the characteristics of available precipitation and its abnormal characteristics during its growth period in Ningxia were analyzed based on monthly precipitation （March- September）, temperature, and NCAR/NCEP reanalysis data in 9 observation stations from 1961 to 2010. E Result l In recent 50 years, the available precipitation during the growth period of crops in central drought area and south hilly area varied a lot, more in the south and less in the north. The available precipitation in these two areas was reducing and varied a lot in different ages. The available precipitation was less in the middle drought region after 1970s and in the southern hilly region after 1990s and the available precipitation in middle drought area changed significantly. The available precipitation in the two areas appeared in July, August, and September, above 76% of general growth period, while that in March, April and May was 14% lower than that in growth period. No abrupt changes in central drought area and south hilly area. There were the periods of 5 -7 a and 2 -3 a oscillations in the middle drought region, 2 -3 a and 10 -12 a oscillations in the southern hilly region. There were negative anomaly field at 500hPa height in high-precipitation years between the Baikal and the China＇s northwestern, and there were positive anomaly field in low-precipitation years. [ Cenclusion] The study provided reference for the reasonable utilization of available water resources in cen- tral and south Ningxia.

Research of Water Quality Analysis,Treatment and Reuse Technology for Rainwater on the North University Campus

The pollution situation of different underlying surface and the change rule of each water quality index were researched,on the basis of rainwater quality monitoring by different approaches in a university campus. The results showed that due to some factors,such as the underlying surface material pollution,road materials,road surface pollution condition and surrounding atmospheric environment quality,the pollution of different underlying surface rainwater would be different. Main pollutants of rainwater runoff in the city campus area were such as COD,SS,NH;-N,TP,etc. Ultimately,along with the increase of accumulated rainfall,the pollutants tended to gradually decrease. The road rain pollution was more serious than roof runoff pollution and the early rain pollution was serious,but the late rain water quality was much better. According to the rainwater conditions,subsequent rainwater recycling technology and processing technology were determined as a way to alleviate the problem of water shortage and water pollution.