The problem of the Quaternary, geological environment and desertification |
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Authors: | L Nianfeng T Jie Z Dianfa |
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Institution: | (1) College of environment and construction engineering, Changchun University of Science and Technology, Changchun City, Jilin Province, P.R. China, e-mail: tang@cust.jl.cn, CN |
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Abstract: | The Quaternary geological environment supplied mankind with a habitat and rich natural resources such as forest, meadow,
water, etc. Mankind has developed to modern civilization through a very long history. During the last 100 years the area of
desertification has been expanding, natural resources have been consumed, and eco-environments plundered. Mankind felled forests,
cultivated grassland, and increased farmland because of unceasing increasing population and the need for materials. In a period
of 50–100 years, mankind's destruction could change good meadow into desert. The following examples are evidence: Shangdu
grassland in Inner Mongolia and the west grassland of Jilin Province have been changing into desert rapidly. Two concepts
of destructive power (D) and bearing capacity (B) can be used to describe this process. When D<B, the ecosystem keeps good circulation, D=B, eco-balance reaches critical state, and D>B, ecosystem loses balance, the environment is destroyed and developed toward desert. The law of destructive power increasing
with time accords with logistic curves and can be expressed by a logistic model. Destructive power (D) increases with decrease of bearing capacity (B);D and B represent a reciprocal relation. With a logistic model the developing process of desertification can be studied and the developing
rate and strength of change can be forecasted.
Received: 20 July 1998 · Accepted: 1 December 1998 |
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Keywords: | Quaternary geological environment Bearing capacity Desertification Logistic model Land use |
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