| A quantitative study on human factors in the increasing of land agricultural productivity in arid area — A case study of Tarim River basin |
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| DOI：10.7606/j.issn.1000-7601.2004.03.38 |
| Key Words: land agricultural productivity human activities Tarim River Basin projection pursuit dynamic analysis arid area |
| Author Name | Affiliation | | LI Xiang-yun | School of Public Policy ＆ Management／Development Research Academy for the 21st Century,Tsinghua University,Beijing 100084,China；The institute of Geographic Science and N atural Resources Research,CAS,Beijing 100084,China | | YANG Jun | College of Resources and Environment,China Agricultural University,Beijing 100094,China | | YANG Li-xin | Xinjiang Agricultural University,Urumqi 830052,China | | WANG Li-xin | College of Resources and Environment,China Agricultural University,Beijing 100094,China |
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| Abstract: |
| The projection pursuit regression (PPR) , a new exploratory data analysis method, was used to make a quantitative evaluation on human factors in the increase of land agricultural productivity (LAP) in arid area. Taking the 40 counties in Tarim River basin as samples, using food output as dependent variable, and 5 factors of human activities (water, cultivated land, agricultural labor forces, fertilizer, mechanical power) as independent variables, 5 PPR models were set up at 5 time phases (1980, 1985, 1990, 1995, 2000) so as to study the contributing degrees of the factors of human activities in the LAP increasing. The computing results show that the contributing degrees of resource factors (water and land) have appeared some descend since 1990's but is still the dominant factors in LAP increasing. The increasing role of fertilizer is obvious. The results also prove that PPR is a practicable method for the similar studies. |
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