The objective of this research is to study the relationships between the biomass of the submerged aquatic vegetation, the nutrients, and the primary production in the Condoriri River. Field measurements were conducted to determine variations of physicochemical parameters, biomass, and nutrients in water and aquatic plants during dry and wet seasons. Macrophyte biomass had correlations of negative gradients with electric conductivity (EC) (R2=0.33, P<0.03) and phosphorus content (R2=0.47, P<0.01). Alkaline pH>7.5 and EC (132.5 μS·cm-1) affected the growth of the aquatic plants. The nutrient loads during the wet season were related to high macrophyte biomass. Submerged aquatic vegetation influenced the river metabolism in both seasons. Primary production and macrophyte biomass exhibited a good agreement (R2=0.79).
Tropical Cyclone (TC) activity is an important feature of China's climate that can have important impacts on precipitation and cause extensive property damage. In particular, precipitation from TCs contributes a significant portion of overall precipitation in China. This study deals with TCs that influenced China and focus on TC precipitation's temporal and spatial regularity analysis. Surface TC precipitation datasets were generated by interpolation of precipitation contour maps based on station-observed precipitation from Typhoon Yearbook1) compiled by Shanghai Typhoon Institute of China Meteorological Administration (CMA_STI), and the interpolation results were verified by satellite-based derived precipitation data products from Fengyun(FY-2C)2) geostationary Meteorological Satellite. Based on the interpolated precipitation data (STI), two aspects were found in this research. Firstly, the TC precipitation gradually decreased from the southeast to the northwest of China, and the main area of TC precipitation concentrated in the southeast of China, including Hainan, Fujian, Zhejiang and Guangdong, while the most significant TC precipitation fluctuations arise in Shanxi, Henan and Hebei provinces. Secondly, there is no trend that was detected to pass 95% confidence level in annual TC precipitation and maximum TC precipitation from 1951 to 2008 in China, but a cycle of 5.43 years based on 95% confidence level was detected to be existing for annual maximum TC precipitation in China.