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| THE ANALYSIS OF THE OASIS ENVIRONMENTAL CHANGE AND ITS REASON OF THE LOWER REACHES OF THE ARID REGION——A Case Study of Minqin County in the Lower Reaches of Shiyang River in Hexi Corridor, Gansu Province |
| YANG Yong-chun |
| The Department of Resources and Environment Institute, Lanzhou University, Lanzhou 730000, China |
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Abstract Based on investigating social materials, this paper analyzes the oasis environmental change and its reason of the Minqin in the Arid Region in Western China, which is lower reaches of Shiyang River in Hexi Corridor, ansu Province. The desertification and salinization in Minqin Basin show Minqin basin ecosystem has been in the brink of bankruptcy and its environment has gone worse. However, the precipitation has been generally steady since 1950, so human factor is a main reason of ecological environment change. Furthermore, it is discussed that it is human mechanism that causes the oasis change with human behavior of water use and quantity balance of water use. Minqin oasis change is related to expanding mechanism of traditional agriculture which can not be easily broken in limited time. We think all the oasis environmental changes of the lower reaches in the Arid Region in Western China have exposed the worse trend that is speeding in the recent and modern period. Minqin Basin has the process of the rapid decline of the underground water level, desertification, salinizification, degenerating vegetative cover that have greatly affected the agricultural production since 1950's.The human reason caused the environmental change is chiefly the unlimited demand of agricultural water use incited by enlarging farming land caused by rapid increasing population of the Shiyang reaches. The surface water decline flowing from the upper reaches and the increasing water use demand have explained the decline of underground water level and the worse quality of the underground water that caused the rapid salinizification and the rapid decline of the crop production which is one of the main facto rs of the enlarging farming land.All of these factor mentioned have contributed the degenerating vegetative cover and the disaster of the ecosystem. As a result, if the hum an mechanism causing the aggravating environment cannot be broken quickly, all human actions to reverse the worse trend of the oasis change in the same area will have little function.
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Received: 18 June 2001
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2003, Vol. 18 
