To study the relationship between the enlargement of Nanjing City and urban greenhouse effect,the temperature of Nanjing Station and its suburban stations during 1961-2000 was analyzed.The results showed that the temperature of Nanjing area has increased gradually and the urban heat island effect has developed quickly.The average temperature increment in winter is the greatest,followed by that in spring,autumn and summer,most of which was caused by the greenhouse effect in Nanjing area.Finally several effective countermeasures have been proposed correspondingly.
[Objective] This study was conducted to investigate the effects of different irrigation amounts on rice leaf physiology and water use efficiency. [Method] The irrigation test with three different treatments was carried out in the Agrometeo- rological Experimental Station of Nanjing University of Information Science ＆ Technology. [Reset] Under flood irrigation, the rice leaf temperature was lower than wet irrigation by 0.4-0.7 ℃; when the strength of photosynthetically active radiation was in the range of 800-1 800 gmol/（m^2·s）, the average stomatal conductance of rice leaves under flood irrigation was higher than that of the wet irrigation treatment by 0.123-0.183 mol H2O/（m^2·s）, and the leaf water use efficiency was higher than that of the wet irrigation treatment by 0.24 g/kg; after 10：00 every day, the water use efficiency under flood irrigation was always higher than that of the wet irrigation treatment; and compared with the wet irrigation treatment, the rice of the flood irrigation treatments had higher leaf water use efficiency, and final yields were also remarkably improved by 5.89%-13.97%. [Conclusion] This study will provide a practical reference basis for field management.
In this paper, the hydrology of Sun Jia Catchment, a small catchment with mixed agriculture in Subtropical Southeast, China, is studied. The objective of the research is to characterize the catchment flows in an agricultural catchment with an irrigation system in Subtropical China and to estimate catchment irrigation flow using hydrograph analysis methods. In the research, the weighting model and multiple regression model were established to estimate catchment irrigation outflow according to hydrographs of the inflows and outflows of the catchment. In the end, it is concluded that the estimated irrigation outflows amounted to 3 695 mm, 2 613 mm and 2 757 mm during 2001, 2002 and 2003, respectively, which covered 70%, 60% and 64% of the total catchment outflows in the corresponding years.
