Interannual variations of summer rainfall over Asia and their associations with geopotential heights in the Northern Hemisphere, tropical convective activities and global sea surface temperature (SST) anomalies are investigated. The Empirical Orthogonal Function (EOF) analysis is applied to the summer rainfall data (JJAS) at 220 stations from 1951 to 1991 in order to reveal the spatial structure and its temporal evolution in the interannual variation of summer rainfall over the Asian region including from India to East Asia. The EOF 1 is detected as the component associated with the Warm Event of ENSO. In other words, the spatial pattern and its time coefficients of EOF 1 indicate that the amount of precipitation decreases over India and the north of China in El Nina years. The EOF 2 has a spatial structure with the same sign from India to East Asia; in particular accompanied with large signals in the middle latitude of East Asia. The variations of these EOFs are connected with those of tropical convective activities and SST anomalies. The variation of EOF 1 is suggested to be associated with the movement of heat source from southeastern Tibet to the southwestern part of China from the correlation coefficients pattern both for the geopotential height fields and the OLR. On the other hand, the EOF 2 is related to variations of convective activities extending from the north of the Philippines to the eastward along 15°N, which are accompanied by negative correlation coefficients to the variation of SST anomalies from the South China Sea to the eastern equatorial Indian Ocean.
Much rice grows on land served by irrigation systems where water moves to fields through canals and ditches. Some irrigation systems have plenty of water. Others do not. This study examines three systems which almost every year experience moderate shortages of water and occasionally experience severe shortages. Water distribution within the systems is managed entirely by farmers. The water diversion structures on the canals and ditches are highly manipulatable. The farmers have devised water distribution procedures that are readily adaptable to the varying needs of fields and varying levels of water availability from place to place and time to time. Therefore, crop losses owing to water shortages have been minimal.
China and Japan, as two superpowers in the Asian region, have one of most complicated foreign relations in centuries. Since the Chinese economic reform in 1978, Japan has provided financial assistance to China, making China the second largest country (behind Indonesia) to receive Japanese foreign aid in years. On the one hand, Japan has clear goals for its foreign aid programs based on geo-strategic considerations with respect to China. On the other hand, Japanese yen credit has often become a “souvenir” to soothe Sino-Japanese relations manipulated by both Japanese politicians and bureaucrats. Because of the both complicated geopolitical and geoeconomic relations between two countries, certain scholars have mistakenly concluded that the Japanese government does not rely upon predetermined motives when providing aid. This research, however, illustrates that Japanese yen credits to China have been a major geo-strategic tool of Japanese foreign policy of promoting Chinese economic reform.