[Anthropogenic Ammonia Emission Inventory and Its Spatial Distribution in Chang-Zhu-Tan Region].

Based on the best available activity data and emission factors, an anthropogenic emission inventory of NH3 was established for the Chang-Zhu-Tan region with spatial resolution of 3 km x 3 km. The results showed that the total quantity of NH3 discharged from anthropogenic sources in the Chang-Zhu-Tan region was 7.27 x 10(4) t, and the average intensity of NH3 emission was 2. 59 t x km(-2). The livestock and poultry industry, and the farmland ecosystem, were the major contribution sources of the anthropogenic NH3 emissions, accounting for 58. 60% and 29.73%, respectively. As for NH3 emission from the livestock and poultry industry, the major contributors were beef, laying hen and pork pig, accounting for 26.26%, 21.40% and 18.43%, respectively. In the Chang-Zhu-Tan region, the quantities of NH3 emissions from Ningxiang county, Xiangtan county and Liuyang city were larger than those of the other districts, accounting for 17. 49%, 12. 82% and 12.02%, respectively. The intensities of NH3 emission from Shifeng and Yuetang districts were larger than those from other districts, reaching up to 9.14 t x km(-2) and 5.01 t x km(-2), respectively. The spatial distribution characteristics revealed that the NH3 emission mostly originated from large point sources.

Evaluating controlling factors to Al(i)/(Ca + Mg) molar ratio in acidic soil water, southern and southwestern China: multivariate approach.

Al(i)/(Ca + Mg) molar ratio in soil water has been used as an indicator to the effects of acid deposition on terrestrial ecosystems. However, the main factors controlling this ratio have not been well documented in southern and southwestern China. In this study, we presented the variation in inorganic aluminum (Al(i)) and Al(i)/(Ca + Mg) molar ratio in different sites and soil horizons based on two to three years monitoring data, and evaluated the main factors controlling Al(i)/(Ca + Mg) molar ratio using principle component analysis (PCA) and partial least square (PLS) regression. Monitoring data showed although Al(i)/(Ca + Mg) molar ratios in most soil water were lower than assumed critical 1.0, higher molar ratios were found in some soil water at TSP and LXH site. Besides acid loading, both soil properties and soil water chemistry affected the value of Al(i)/(Ca + Mg) molar ratio in soil water. Partial least square (PLS) indicated that they had different relative importance in different soil horizons. In A-horizon, soil aluminum saturation (AlS) had higher influence on Al(i)/(Ca + Mg) molar ratio than soil water chemistry did; higher soil aluminum saturation (AlS) led to higher Al(i)/(Ca + Mg) molar ratio in soil water. In the deeper horizons (i.e., B(1)-, B(2)- and BC-horizon), inorganic aluminum (Al(i)) in soil water had more and more important role in regulating Al(i)/(Ca + Mg) molar ratio. On regional scale, soil aluminum saturation (AlS) as well as cation exchange capacity (CEC) was the dominant factor controlling Al(i)/(Ca + Mg) molar ratio. This should be paid enough attention on when making regional acid rain control policy in China.