Grant-in-Aid for international Scientific Research
|Allocation Type||Single-year Grants |
|Research Institution||University of Tsukuba |
NISHIZAWA Toshie (1988, 1990) Professor, Institute of Geoscience, The University of Tsukuba, 地球科学系, 教授 (90062512)
西澤 利栄 (1989-1990) 筑波大学, 地球科学系, 教授
MULLER Kieth 国立セルジッペ大学, 人文学部, 助教授
PINTO Magdal IBGE(国立地理統計院), 国際地図部, 部長
SILVA Leonid SUDENE(東北開発庁), 国際協力部, 部長
YAGASAKI Noritaka Associate Professor, Dept. of Geography, Yokohama National Univ., 教育学部, 助教授 (30166475)
NAITO Toshihiko Assistant Professor, Institute of Botany, University of Tohoku, 理学部, 助手 (20004393)
HIDA Noboru Professor, Department of Geography, Akita University, 教育学部, 教授 (70015832)
YAMASHITA Shuji Professor, Department of Geography, Tokyo Gakugei University, 教育学部, 教授 (80064731)
MASUDA Fujio Assistant Professor Institute of Geos., University of Tsukuba, 地球科学系, 講師 (30091929)
SAITO Isao Associate Professor, Institute of Geos., University of Tsukuba, 地球科学系, 助教授 (90006586)
MULLER Keith D. Visiting Researcher Department of Geography Federal Univ. Serjipe
PINTO Maria Magdalena Vi Professor, Division of Maps, IBGE.
FILHO Leonides Aves da S Director of International Cooperation, SUDENE
TSUCHIYA Akio Graduate Student, Institute of Geos., University of Tsukuba
|Project Period (FY)
1988 – 1990
Completed (Fiscal Year 1990)
|Budget Amount *help
¥36,400,000 (Direct Cost: ¥36,400,000)
Fiscal Year 1990: ¥13,500,000 (Direct Cost: ¥13,500,000)
Fiscal Year 1989: ¥14,900,000 (Direct Cost: ¥14,900,000)
Fiscal Year 1988: ¥8,000,000 (Direct Cost: ¥8,000,000)
|Keywords||Northeast Brazil / Desertification / Animal grazing / Deforestation / Salinization / Urban climate / Coating stand|
This is the report of a continuous three year research projecting Northeast Brazil with the title of "the Regional Differentiation of Changes in the Ecosystems caused by Changing Patterns of Land Use and Water Use". Our research project is undertaken in 1988, 1989, and 1990 in cooperation with SUDENE and IBGE.
The purpose of our field work of this project was to clarify the processes of desertification of the environment in Northeast Brazil which is caused by human impact. Generally, human impact mainly consists of crop raising, animal grazing, deforestation, and irrigation.
Subsistence farming combining a number of crop such as maize, two or three kinds of beans, watermelon, and squash is prevalent. These crops are interplanted with the arrival of seasonal rains and after the harvest fields are generally converted to grazing during the dry season. This pattern of agricultural land use is repeated annually. Normally, in the past, cultivated land was converted to fallow after several year
s of cropping. As the vegetation grew during the fallow period, a secondary growth of vegetation called "capoeira" resulted. However, recent population increase and economic pressure have already modified this pattern of agricultural land use. Further, irrigation from man-made lakes or river, strongly influences farming systems. In the case of irrigation farming, soil salinization is extremely important. Soil salinization is closely related to the drainage of irrigated ater, and to the quality of irrigated water, Moreover, wash-out of salinity from soil by rainfall also affects salinization. The effect of wash-out also depends on the topography of farmland. Grazing of livestock in the semi-arid interior includes cattle, sheep, and goats. Cattle grazing predominates in the regions of relatively less dry climates, and sheep and goats in drier regions. Our findings show that the predominant livestock types are determined not only by the growth of caatinga, but also the composition of edible floristic species in the vegetation and the stubble following the harvest of crops.
The species composition of the original caatinga is mainly influenced by environmental factors, especially water deficit and water storage. However, its species composition changes gradually by human impact such as animal grazing and deforestation.
Finally, we must examine deforestation. Deforestation has been recognized as the most severe cause of desertification in the world. Deforestation is a severe problems in the semi-arid interior of Northeast Brazil as well. Deforestation of caatinga results from the use of trees for firewood, charcoal, and brick and tile production.
As an additional part of this research we conducted measurements of air temperature and humidity at some cities. Because there is a substantial lack of data and information about urban climates of tropical cities, results from such a research can be a great contribution. Less