【作者】 白祥；

【导师】 金海龙；

【作者基本信息】 华东师范大学 ， 自然地理学， 2010， 博士

【摘要】 湖泊湿地是干旱区湿地的主要类型之一,对维持“山地—绿洲—荒漠—湖泊(MODELS)"生态系统的稳定性至关重要。艾比湖湖泊湿地独特的地理与生态区位使其生态过程对博尔塔拉蒙古自治州、天山北坡经济带和亚欧大陆桥新疆段社会经济的可持续发展影响深远。近60年来,在自然背景与人类活动的双重胁迫下,艾比湖湖泊湿地面积急剧萎缩,裸露湖底成为我国四大沙尘源区之一,艾比湖流域成为新疆仅次于塔里木河下游的第二大生态退化区。本文以艾比湖湖泊湿地为研究靶区,以艾比湖湖泊湿地生态脆弱性现状、动态过程的生态要素表征、退化驱动机制为研究对象,以现代地学、生态学、水文学、恢复生态学等学科理论为指导,运用野外调查、室内试验、遥感解译、模型构建等方法,分析和探讨了艾比湖湿地水体、土壤、植被等生态要素的空间分异,湿地面积变化,水、土、植被等生态要素的变化,湿地与非湿地之间的转化,湖泊湿地生态过程的自然与人为驱动力等问题,并运用统计方法和数学模型,结合收集到的水文、气象、社会经济资料,构建出艾比湖湖泊湿地退化驱动机制模型,依据模型对湖泊湿地变化趋势进行了预测。本论文的主要结论如下：(1)近60年来艾比湖湖泊湿地退化严重。湖泊湿地面积萎缩导致裸露湖底演化成为沙尘暴源区,湖泊湿地生态系统和湖滨荒漠生态系统逆向演替导致湿地生物多样性受到严重损害。(2)艾比湖湖泊湿地生态脆弱性在水体、土壤、植被等生态要素空间分异表现显著。艾比湖湿地五种主要水体类型中,浅层地下水各项理化指标空间分异最为显著,泉水各项理化指标空间分异最不突出。土壤理化性质空间分异表明湖泊湿地动态过程对土壤质量有较大影响。艾比湖湿地不同区域植物物种多样性差异大,物种多样性指数变化范围为0.1285-1,Margalef指数和Gleason指数在表征研究区植物物种丰富度时具有很好的一致性,均表明艾比湖湖泊湿地植物物种丰富,植物生态优势度差异较小,在0.2321-1之间变动。(3)艾比湖湿地生态过程在湖泊湿地面积变化、湿地与非湿地转化、水、土、植被等生态要素的改变等三个层面均有所体现。艾比湖湖泊湿地面积年内变化较大,面积最大值多出现在3月-5月,最小值多出现在7月-10月。近60年湖泊湿地的年际变化经历了急剧减小→相对稳定→再次干缩三个阶段。湖泊水体矿化度表现出急剧升高、逐渐减小、缓慢升高的趋势。近30年湖泊湿地周边典型区域土壤养分的变化呈现有机质含量减小、土壤钾元素含量迅速减小等特征。湖周植被由湿生、中生向旱生、超旱生和盐生、耐沙生种类方向演替。1990-2005年的15年间,湿地与非湿地相互转化体现出湖泊湿地持续增大,河流湿地先减小、后增大的特点。土地利用/覆被趋势和状态指数(Pt)为0.5070,湿地与非湿地之间的转化多体现为单向转化。(4)参数t检验和Mann-Kendall非参数检验结果表明：近50年来艾比湖湿地四季及年平均气温普遍升高,年平均降水量增加,年相对蒸发量下降,艾比湖流域五条主要河流年径流量均有不同程度的增加。Hurst指数分析表明,艾比湖入湖地表径流的增长趋势仍将持续下去。运用时间序列周期方差分析外推的方法确定艾比湖入湖河流的变化周期为21年,其中博尔塔拉河为21年,精河为18年。此外,古尔图河变化周期为18年,奎屯河、四棵树河同为8年。趋势叠加预测模型和均生函数预测模型对入湖地表径流的预测结果与Hurst指数分析结果一致,在未来9年艾比湖入湖地表径流以平水年为主,兼有偏丰水年出现,入湖地表径流较为充沛。就地表径流的变化趋势而言,其有利于艾比湖退化湿地的生态恢复。(5)对艾比湖流域5个气象站点1960-2007年温度、降水资料以及流域5条主要河流6个水文站点1957-2007年径流资料的统计分析表明,影响入湖地表径流变化的主要气候因子是温度变化。年平均温度、夏季平均温度和秋季平均温度发生突变的年份为1996年。计算结果显示,1997-2007年11年间年径流量在气候变化的影响下增加了14.92%。对气候因子与艾比湖湖泊湿地面积之间进行灰关联分析,结果表明,艾比湖湖泊湿地面积变化主要受到流域内夏、冬气温变化的影响。进一步分析发现,温度变化是通过改变山区径流补给量而影响湖泊湿地生态过程的。(6)流域人类活动对湖泊湿地生态过程的影响主要是通过农业生产规模的改变而实现的,农业生产用水是流域内人类活动耗水最主要的方式。对艾比湖流域1990-2005年LUCC分析表明,耕地面积的持续扩大是这一阶段LUCC最突出的特征,趋势和状态指数(P)为0.8262,表明艾比湖流域LUCC处于极端不平衡状态。对11项主要社会经济要素进行主成分分析,结果表明,艾比湖湖泊湿地面积变化主要是由耕地面积尤其是经济作物的面积变化所决定。(7)通过对自然背景与人类活动驱动力的分析发现,决定艾比湖湖泊湿地退化过程最主要的影响因素为入湖地表径流量与耕地面积的变化。以耕地面积变化率、入湖地表径流量变化率、湖泊湿地面积变化率为组成要素,构建出反映艾比湖湖泊湿地退化驱动机制的径流变化率模型：并对改革开放以来艾比湖流域土地开发的情况进行分析,认为1977-1994年为土地持续开发模式,1995-2005年为土地稳定开发模式,对驱动机制模型的参数进行合理化筛选,确定了有利于湖泊湿地生态恢复的土地开发力度,将其定义为最佳开发模式。基于上述三种土地利用模式,对未来9年内湖泊湿地的退化趋势进行预测。结果表明：如果以1977-1994年土地开发力度对流域内的土地资源进行持续开垦,在气候条件等外在条件无突变的状态下,湖面积有可能将于2014年消失；如果以1995-2005年土地开发力度对流域内的土地资源进行稳定开发,在未来9年内湖面积将在231.39km2-591.19km2波动；如果以有利于湖泊湿地生态恢复的土地开发力度对流域内的土地资源进行合理开发,湖面积将在487.09km2-616.96km2的范围内波动。更多还原

【Abstract】 Lake wetland is the primary category of wetland in the dry area, which plays the key role in maintaining the stability of "mountain-oasis-desert-lake" system.Ebinur lake wetland is located in the unique geography and ecosystem area, whose degradation will severally threaten the ecosystem safety of the northern Tianshan mountain slope economic zone.Over the past 60 years, under the influences of natural backgrounds and human activities,Ebinur lake wetland area has declined quickly, whose bald bottom becomes one of four sandstorms sources and makes it become the second ecosystem degradation area next to lower reaches of Tarim River in Xinjiang. This thesis selects Ebinur lake wetland, the largest lake wetland in Xinjiang, as the study area and chooses the ecological vulnerability present situation, typical eco-features of degradation process and its driving system as study object. It is under the guidance of modern geography, ecology and adopts field research, experiment, remote sensing techniques, model construction methods to analyze and discuss Ebinur lake’s eco-elements space differences, such as water, earth, plants; meanwhile it analyses the features of wetland area,eco-factors like water, earth and plants as well as the transformation between wetland and non-wetland in the wetland degradation process.It applies many methods and math model,together with the collected water, climate, social economic files to construct the model of Ebinur lake wetland degradation process. Furthermore, it predicts the degradation tendency in accordance with this model.The thesis main contents are as follows:(1)Ebinur lake wetland has been decreasing dramatically in the recent 60 years.The decrease of wetland results in the change of bald bottom becoming the origin of sand and the wetland ecosystem and lake surrounding desert ecosystem deteriorate change has greatly harmed the creatures diversity.(2)The big space differences of Ebinur lake present degradation situation are obvious. The space differences of Physical and Chemical property on different types of water show a characteristic as follows:the biggest one is shallow underground water and the smallest is spring water. Among these the water mineralized degree shows the discipline of underground water-lake water-deep underground water-spring water. The potassium containing amount space difference is small, but the ammonia-nitrogen containing amount space difference is big. The earth of Ebinur Lake wetland contains lower water amount, and shows the discipline of surrounding wetland-river flowing into lake mouth-spring spreading area-desert. The Ebinur lake’s surrounding earth’s pH value space spreading characteristics are:north-south, east-west, and northwest-southeast. Ebinur Lake wetland earth contains comparatively low amount of organic matter, and its space difference shows the characteristic of Aqiksu River surrounding earth organic matter containing amount-lake surrounding organic matter amount. Different plants’sub-creatures show obvious varieties in Ebinur lake wetland, and have apparent space difference. Two sorts of creatures’ variety Margalef and Gleason show common tendency in the study area. The eco-advantage degree shows clear differences.(3)Ebinur Lake wetland’s degradation process presents in the following fields: the wetland area change, eco-factors change, such as water, earth and plants and transformation between wetland and non-wetland. Ebinur lake wetland area varies greatly in one year. The largest area time is between March and May, while the smallest July and October. Over the past 60 years the annual change can be divided three stages:increasingly degradation, relatively stable and slowly dry. The water mineralizing degree shows the tendency of increasingly rise, gradually decrease and slowly rise. In recent 30 years typical area’s earth nutrition change shows characteristic of organic matter amount decrease, earth potassium element decrease rapidly. The lake surrounding plants changes in the direction of wet growth, neutral growth, super dry growth, salty growth and sandy growth. In the 15 years of 1990, wetland and non-wetland change process shows the characteristic of lake wetland grows constantly, river wetland grows first and decreases then, smash wetland decreases first and then increase.(4)The results of parameter and non-parameter statistic test show that the yearly average temperature and in different seasons has an increasing trend. Yearly mean rainfall increasing too.But yearly evaporate has a decline trend. The streamflow of five main rivers in Ebinur lake basin shows different level increasing trend.The Hurst index analysis presents the streamflow which flows into Ebinur lake will keep increasing trend in future.The period analysis reveals that the change period of streamflow which flows into Ebinur lake is 21 years, while the streamflow in Bortala River is 21 years. The change period of Jing River is 18 years.In addition, the change period of Gurtu River is 18 years. Both of Kuitun and Sikeshu River change periods are 8 years.The hydrological forecasting results by trend superposition model and mean gengerating function model presents the same change trend with Hurst analysis and shows the streamflow in the river which flows into Ebinur lake will increasing in the next 10 years.(5)Using the temperature and rainfall materials from 1960 to 2007 from five weather station in Ebinur lake basin, the author concludes that the key to climate change is the temperature change. The abrupt change year of yearly average temperature,mean temperature in summer and autumn is 1996 and the year of streamflow which flow into Ebinur lake is 1997. Because of this, the increase in stremflow under climate change is 14.92% during 1997-2007. Relationship between the main climate factor and the area of Ebinur lake wetland shows that the two most important climate factor which influence the Ebinur lake wetland are the changing of summer and winter temperature in Ebinur lake basin. Futhermore,temperature change causes the wetland degradation by means of changing the mountain streamflow supply force.(6)Human activity causes the change of lake wetland by means of changing agriculture producing scale. The author founds out that agriculture water usage is the main human activity water consuming form according to the analysis of human activities characteristics between 1950 and 1990. The author analyses the land use and plants covering and finds out that apparent characteristic of land use and plants covering transformation in this period is that farming land increasing tendency and condition Pt index is 0.8262,which shows the land use and plants covering in Ebinur Lake is in extreme unbalanced condition. The author selects economic factors such as total area of farming, economic crop, a food crop to find which factors are the decision to area of lake wetland. The results is area of farming especially the area of economic crop.(7)Through the analysis of natural backgrounds and human activities driving factors, it is concluded that the key factor to the degradation of Ebinur wetland is the streamflow and farming area. According to farming area change rate, streamflow change rate, lake wetland area change rate, the author forms the model: which reflects wetland degradation driving factor. According to historical data, the author analyzes the farming area change rate, streamflow change rate and lake area change rate and concludes that it is abnormal development stage between 1977 and 1994 and normal development stage between 1995 and 2005.In accordance with overall conclusion, together with computer parameter model result, the author chooses stable development, constant reclamation and appropriate reclamation and predicts the wetland area in the following 9 years. If the reclamation could be kept stable,the lake area can be 231.39km2-414.39km2,while if constant reclamation continues, the lake will disappear completely in 2014.However, the appreciate reclamation will keep the lake area between 501.94km2-543.24km2.更多还原