中国沙漠化研究的理论与实践

中国的沙漠化研究的理论与实践在过去的十多年里取得了一些成果。据此,本文对沙漠化的概念、成因、过程、指征、后果、发展趋势及其治理等方面进行扼要的介绍。研究表明,沙漠化是一种人为活动与自然资源、环境不相协调所产生的以风沙活动为主要标志的土地退化过程。我国北方沙漠化土地的蔓延速率从50年代末期至70年代中期的年均1560km2发展到近十多年来的年均2100km2;实践证明,沙漠化土地作为一种土地资源可以通过合理的整治过程而恢复其原有的生产潜力。

THEORY AND PRACTICE ON SANDY DESERTIFICATION IN CHINA

Arid and semi-arid regions occupy nearly half the area of China, where are abundant in natural resources and great potential for developing. However, these regions were suffered seriously from land sandy desertification which has become a very strong limiting factor for the local development. On the basis of research and practice for many years, the authors believe that sandy desertification is an environmental degradation process characterized by wind erosion resulted from excessive human activities against natural resources and environment under the condition of sandy land surface and arid with frequent gale. Between the important human and natural contributing factors in desertification, the former is the active and major one. The evolution of sandy desertificatien depends on the process of wind erosion after the ecosystem was destroyed by human impact, and is mainly characterized by the wind-erosion landforms. The sandy desertification lead to rapid declination of the biomass production and the land potential, and even loss of the land resources. It will be effective to combat desertification by revising the pattern and intensity of human economic activities. The trend of sandy desertification will depend fundamentally on the human impact in coming decades. The desertification study involves its histor cal and modern processes, and its area, causing types, evolution and combat measures have been defined for different period by means of field investigation in large range, observation, experiments and analyses. According to the study, the last 40 years was an accelerating period of sandy desertification development, from the end of 1950's to the middle of 1970's, the desertified land had expanded 1560 km² annually in average, and during the last decade it has gone up to 2100 km², the desertified land has reached 197 000 km² in North China. Remote sensing and wind tunnel experiments made the quantitative study possible for the desertification. A number of typical examples have proved that the desertified land as one of land resources can be restored in its potential productivities for agriculture and animal husbandary through different harnessing measures.