【作者】 蔺海明；

【导师】 胡恒觉； 王立祥；

【作者基本信息】 甘肃农业大学 ， 作物栽培学与耕作学， 2003， 博士

【摘要】 加快生态环境保护和建设是西部大开发战略的重要内容，深入研究并提出河西绿洲生态环境恢复建设与发展的有效途径，有重要的科学价值与实践意义。可对河西走廊绿洲农业生态恢复建设与发展策略提供科学依据。采用生态足迹、环境资产负债、能学分析、问题树分析和比较评价等的研究模型和分析方法，全面系统地研究了河西绿洲农业生态环境的现状、演替规律、存在问题、生态足迹及资产负债动态变化、能流运转规律和恢复重建绿洲生态环境的对策等。通过深入研究得出如下结论： 1．河西地区生态足迹研究结论是：1985年前为生态盈余或平衡，之后步入生态赤字，且赤字程度不断加大。1949年～1980年为生态盈余阶段，1949年全区人均生态承载力为0.55hm~2，人均生态足迹为0.42hm~2，人均生态盈余0.13hm~2。1980年人均生态承载力和生态足迹均为1.02hm~2，二者正好平衡；1980年～1985年，人均生态承载力与生态足迹均呈快速增长阶段，出现短期的平衡状态；1985年～2000年为生态赤字阶段，该阶段人均生态承载力与生态足迹均为下降趋势。2000年人均生态承载力1.78hm~2，而人均生态足迹为2.08hm~2，人均生态赤字0.3hm~2。酒泉、武威、张掖3市和永昌县的生态赤字依次为0.63hm~2，0.30hm~2，0.14hm~2和0.13hm~2。生态赤字表明农业发展已远离可持续发展。无论从河西地方尺度还是从全球尺度看，河西地区处于非可持续性状态。 2．河西地区环境资产与负债的研究结论是：全区的环境资产不断减少，负债值逐年增大。其阶段性变化是1949年～1975年呈递减态势，由9.6减少到1.6。1980年～1991年有所回升，由2.1上升到4.4。1995年～2000年保持比较平稳，在3.2～3.3范围之内；环境负债呈现持续负增长，由1949年的-1.2增长到2000年的-28.1，并出现3个明显的时段，1949年～1970年的21年平均为-1.41，1975年～1985年的10年平均为-4.12，1991年～2000年的10年平均为-20.33，环境净资产1949年～1970年呈现下降趋势，但一直为正值(8.4～1.3)，1975年出现负值(-0.5)，到2000年负债达到-24.9，亦说明河西环境资产库存不断减少。 3．对河西绿洲农业生态系统能学特征及演变规律研究结论显示：无机投能水平1991年～2000年的与1949年～1960年比增加50倍，而同期有机投能水平增加97.2％，投能结构发生了根本性变化，由有机投能为主体的格局演变为以无机投能为主体的格局。1949年～1960年无机：有机一1：13．7，1991年～2000年则为1．9：1。1991年～2000年河西全区的产出能水平较 1949年～1960年增加 3．5倍，但同期产投比由2．34下降到1．98。目前投能水平正处投能适宜区内，仅达到理论投能临界值的65．8％，表明河西地区仍具有增加投能的空间。同时显示，河西投能总量近年来增加的主体是劳动效率性投能提高，而产品效率性投比并不算高。过去研究得出河西投能水平己接近或超过发达国家水平的结论并不确切。 4．在近半个世纪，河西走廊绿洲生态环境呈现局部（绿洲内部）改善，整体（绿洲外围）恶化的态势左000年的绿洲面积较1949年扩大3倍，耕地面积扩大84．3％～98．90，现有实际耕地面积95．3万hln‘～102．9万hm，比统计面积多出38．90～50．00；水资源总量呈现前增后减趋势，1981年～1990年径流量较1956年～1960年增加1．426亿 m‘，1991年～1997年较 1956年～1960年减少 5．208亿 m3。径流量疏勒河一直增加，黑河先增后减，而石羊河一直减少；虽然径流量稳中略减，但可资利用的水资源却严重紧缺，原因一是耕地面积剧增，农业用水过量；二是因平原水库。渠系水面蒸发使 2．5亿 m3～3刀亿 m’水无谓“逃逸”；三是人口增加，城市扩容，用水增加。 5．绿洲生态环境演替规律表现为：绿洲面积扩大的走向是溯河而上，向水系源头推移。绿洲周围形成7k—～10kffi的“生态裂谷带”，绿洲越大，“生态裂谷带”越大，该带既是扩大荒漠化的重灾区，也是沙尘暴的策源地；人工植被增加，天然植被锐减，人工植被扩大的正面效应是“人进沙退”，而无然植被锐减的直接结果是沙漠化面积扩大，水源减少，环境恶化；地表水分配方式由自然分配演变成人工分配，原有水生态平衡打破，生态用水锐减，在下游绿洲中心出现“生态空洞”。地下水因过量开采水位年下降0．sin～l刀m，含盐量上升，水质变差；农田土壤肥力由不稳定向稳定、再向提高演替，出现肥力上升与单产提高同步态势，但农药、残膜污染加重；农田生产力不断提高，向产量、效益、技术集约型演替。 6．提出了恢复和重建河西绿洲农业生态环境的总体思路；确定了恢复和重建河西绿洲生态环境的3个重点，涵盖IO个治理层面，侣项工程技术措施，构成恢复和重建河西绿洲生态环境工程体系，具有很强的操作性和实用性；为达到恢复和重建河西绿洲生态环境总体目标，提出8项具体建议，具有一定的学术价值和宏观指导意义。同时，对目前学术界尚有争论的水资源调蓄、高密度造林治沙，营造速生丰产林、投能水平与结构等进行了讨论，井提出新的学术见解。更多还原

【Abstract】 Speeding up the tempo of environmental protection and construction is one of the major issues in the West Development Strategy. Making a thorough study to find out the reliable measures to ecological resumption in this oasis agricultural area has an important scientific and practical significance. It can provide scientific basis for making a better decision for the ecological resumption. A systematic research has focused on the present ecological condition, development traces, existing problems, ecological footprint, assets and liabilities, energy flow and transformation, and resuming measures through applying such research modes and analyzing methods like ecological footprint, environmental assets and liabilities, systematic analysis, problem tree analysis, comparative evaluations etc. Based on the research, the conclusions drawn are as follows:1.Research on the ecological footprint in this area has shown that the ecological carrying capacity was on the remainder stage from 1949 to 1980. Each person’s ecological carrying capacity in 1949 was 0.55hm2, the ecological footprint was 0.42hm2, on an average level, each has an ecological remainder of 0.13 hm2. In 1980, both the ecological carrying capacity and footprint for each person were 1.02 hm , which showed well balance. From 1980 to 1985, both the ecological carrying capacity and footprint were on a rapid growth stage, which showed a relative balance for a short period. From 1985 to 2000, the ecological carrying capacity was on deficit stage, both the ecological carrying capacity and footprint assumed a decline tendency. Each person’s ecological carrying capacity and footprint were 1.78 hm2 and 2.08 hm2, each had a deficit of 0.3 hm2. The study shows that the ecological deficit in Jiuquan, Wuwei, Zhangye three cities and Yongchang county were 0.63hm , 0.30 hm 0.13 hm and 0.11 hm respectively. These deficits have shown that the agricultural development in this area has deviated far away from a sustainable one. No matter viewed locally or globally, agricultural development in this area can’t be sustainable.2.Research on environmental assets and liabilities in this area has shown that the environmental assets have been reducing continually. Changed bystages, it assumed a decreasing tendency during 1949 to 1975, from 9.6 to 1.6. Then it somewhat rose during 1980 to 1991, from 2.1 to 4.4. From 1995 to 2000, it kept relatively stable, with changing ranges of 3.2 to 3.3. The environmental liabilities also has been decreasing, from -1.2 in 1949 to -28.1 in 2000. During this period, it assumed three obvious stages. On an average level, it decreased by -1.41 from 1949 to 1970, -4.12 from 1975 to 1985 and -20.33 from 1991 to 2000. The environmental net assets assumed a decline tendency from 1949 to 1970, with decreasing ranges of 8.4 to 1.3. In 1975, the decreasing rate began with a negative value (-0.5), and decreased to -24.9 in 2000, which has also shown the environmental assets deposits are decreasing continually.3.Conclusions drawn on the basis of the study on energy characteristic and developing law of Hexi Oasis Agro-ecological system have shown that the inorganic energy input from 1991 to 2000 was increased by 50 times compared with that from 1949 to 1960, while the organic energy input at the same period was increased by 97.2%. The structure of energy input also changed radically, from an organic energy input dependant pattern to an inorganic energy input dependant one. The ratio between the total amounts of energy input and the organic energy input from 1949 to 1960 was 1:13.7, and was 1.9:1 from 1991 to 2000. The energy output capacity from 1991 to 2000 in the whole area was increased by 3.5 times compared with that from 1949 to 1960. But the proportion between output and input at the same period decreased from 2.34 to 1.98. Currently the energy input level is just within an appropriate range, only reached the theoretical energy input critical value of 65.8%. This means, on one hand, there are still spaces for energy input in this area, on the更多还原