Air borne spores and pollens were collected by using Durham Pollen Sampler from 38 metre building top platform in northern suburb of Beijing and observations were carried out accordingly. Distribut
Based on the observed data of soil moisture from locating experiments from 1986 to 1990, the pattern of field water circulation in dryland of northern China, where the mean annual precipitation is 300
The biggest load of water resources for agricultural economy in the Huang-Huai Plainwill only arcount for 67.1 % of the forecasted irrigated area in 2010. The irrigated area and thequantity of water d