【作者】 王水献；

【导师】 董新光；

【作者基本信息】 新疆农业大学 ， 水利水电工程， 2008， 博士

【摘要】 水土资源利用相互作用的方式和程度,取决于区域的自然环境和人为因素的综合影响,自然环境条件是区域水土资源的基本背景,在某种程度上具有控制作用,社会、经济、技术和政策等人文因素是土地利用/覆被变化的诱导因素,在一定程度上起着决定性作用。开都-孔雀河流域位于新疆腹地、天山南麓,是塔里木河流域的一部分。自二十世纪五十年代以来,由于其大规模的水土资源开发,导致区域生态环境发生很大变化。本文是在完成开孔河流域水土开发对生态环境影响研究基金项目的基础上,结合水资源调查、与水有关的生态环境调查、盐碱化遥感调查和国家“973”前期研究专项的成果,建立了开孔河流域水土资源数据库,以遥感影像为主要信息源,利用GIS空间分析技术,定量分析了1973年、1990年和2000年的土地利用/覆被变化过程及其变化速率,分析了自然和社会经济的影响力。并利用遥感技术和方法、生态水文分析法,分析了土地利用/覆被变化对水资源、水质、地下水的生态效应以及水盐分布与植被分布的影响。其主要结果如下:(1)近30年间开孔河流域绿洲的土地利用状况发生了显著的变化,主要表现为耕地的大量增加和天然植被的逐步减少。土地利用程度综合指数表明,开孔河流域土地的土地利用程度始终保持着提升,处于发展期,且后期的土地利用程度提高较前期快。土地利用综合变化趋势指数表明,开孔河流域土地的土地利用综合变化趋势在1973-1990年,研究区处于准平衡状态,类型转换呈现双向态势;在1990-2000年,研究区处于不平衡状态,对于每一类来讲,主要都是单向的不平衡转换。而其驱动力主要来自于人口增长、社会经济发展等两大因素。(2)从景观格局分析,近30年焉耆盆地绿洲区耕地面积迅速扩大逐渐呈连片趋势,并已成为绿洲景观类型中面积最大的斑块类型;天然植被斑块的数量增加,斑块面积减少,聚集度明显减小,这种变化与耕地呈明显的相反趋势,表明天然植被景观的破碎化;就斑块密度指标而言,体现了各类景观类型都呈现出破碎化的趋势;农村居民点和城市的斑块数持续增加,表明区域人口持续增加,而人口增加和经济的增长,对绿洲天然植被区进行了强度开发。趋势模拟也表明在未来时期焉耆盆地人为干扰仍然是土地利用变化的主要方面。(3)绿洲农业的发展深刻的影响着流域的河流、湖泊环境。研究表明,农业灌溉、排水排盐影响了博斯腾湖水质进而影响了孔雀河以及下游水质。河流中总磷、总氮、氨氮浓度增高发生区也多在河水流经的农业区。绿洲农业的发展,大大促进了该地区农用化学品的施用量。而不合理化肥施用方式导致化肥利用率较低,化肥随灌溉水的流失严重。大量的引水不但导致了湖泊水位的急速下降,农业排水排盐也使曾经的淡水湖泊变成了微咸水湖泊;同时也致使湿地芦苇产量的减少和其功能的丧失。(4)基于地学统计原理表明,几十年的绿洲农业水土资源开发对地下水产生很大影响,半方差函数分析结果表明,随着农业灌溉排水以及地下水开采量的不断增大,地下水埋深在小尺度上的随机变异己完全被较大尺度上的空间结构性变异所取代。而地下水矿化度在小尺度上的结构性变异己完全被较大尺度上的随机性变异所取代。经过几十年的灌溉排水,焉耆盆地低矿化度的面积逐渐增加,高矿化度分区面积得到减少;而地下水埋深下降;焉耆盆地边缘地下水埋深的时空变化在更大程度上取决于人类生产活动对地下水的开采。在人类活动最为集中的绿洲中心地带,地下水埋深下降不显著,同时,水质越好的区域地下水埋深降低越明显。通过对研究区地下水矿化度空间变异特征分析表明,地下水体盐化朝着加重方向发展。(5)由水盐演变与植被分布的研究表明,绿洲灌区内部生物多样性取决水盐双梯度影响。盐分不断向湖畔积聚是引起焉耆盆地湖畔生态系统生境恶化的主导因子。在绿洲内部,河畔边缘其物种多样性与地下水埋深关系表明,对埋深小于3m的区域,在埋深小于1.5m时,随着地下水埋深的加大,物种多样性减少;在埋深大于2m时,随着地下水埋深加大,其物种多样性在增加,但埋深在3-5m之间,由于缺乏资料,需进一步研究,来确定绿洲灌区水盐调控最佳生态水位。更多还原

【Abstract】 Land utilization interacts with the water resource, and its type and extend of function depends on the synthetic effect of both the natural environment and the human factors in the field. Natural environment is the basic context of the water and land resource of the zone. To some degrees, the natural environment holds the domination. Human factors, take the society, economy, technology and policy for example, are the guiding factors, and play the role of leading to some extend. The basin of Kaidu-Kongque river located in the hinterland of Xinjiang Uigur autonomy region and the foot of south Tian mountain, and is a part of Tarim basin. Since the 1950s, because of its large-scale development of land and water resources, leading to the regional ecological environment of great change.This paper builds up the database of the water and land resources utilization of Kaidu-Kongque River basin, on the base of completing the research National Nature fund projects of the water and land resource development impact on environmental ecological. It involves the water resource investigation throughout the whole basin, the ecologic environmental investigation relating to water, the remote sensing investigation of the Salinization and the achievement of the national“973”special preparatory research, and selects the remote sensing impression as the major source of the information, making use of the GIS space analytical technology, quantitatively anatomizes the process and rate of the land utilization/coverage conversion in the year of 1973, 1990, 2000 and the ability of the nature and the social economy affection, calculates the effect of the land utilization/coverage conversion on the water reources, water quality, the ecological effects of groundwater, the ecological effects of water and salt pattern and the distribution of vegetation.with the technology of remote sensing, ecohydrologic analytical method. Its chief content is as follows:(1) In the past 30 years, the Oasis land-use conditions of Kaidu-Kongque River Basin have remarkable change, such as the large increase in farmland and natural vegetation gradually decrease. The exponent of Land use grade indicates that the exponent of land-use land has always a degree of upgrading, in a period of development, and the development is fast the latter than the prophase. The trend of integrative land-use change show that the study area is in a quasi-state balance, and has two-way conversion momentum in 1973-1990; the study area in an unbalanced state in the years 1990-2000, for each category of speaking, the imbalances are mainly one-way conversion. And its main driving force comes from the two factors such as population growth, socio-economic development.(2) From the landscape pattern analysis, in past 30 years, the acreage of infield is rapidly enlarged and become to the largest oasis landscape. The number of patch is increase and its area is reducing for natural vegetation, the aggregation degree is significantly reduced. On the contrary, farmland showed the opposite trend, which that the landscapes of natural vegetation fall to piece; from the index of patch density reflects that the various types of landscape present the trend of fragmentation. The patch numbers of rural and urban continue to increase, its show that the region’s population continued to increase. While the increase in population and economic growth, lead to the area of natural vegetation are strength developed. The simulation of Markov model also shows that the land change is main effect by people in Yanqi Basin in the future period.(3) The developments of oasis agricultural are profound influence on the basin’s rivers and lakes environment. Research shows that the water quality of Bosten Lake Kongque river affected by agricultural irrigation, drainage salt water. The concentration of TP, TN and NH4 has increased in the river flows through agricultural areas. The development of the agricultural oasis greatly resulted in the area of application of chemicals. Irrational use of fertilizers, and the way led to a lower utilization of fertilizers, fertilizers is serious loss of with the irrigation water. A lot of water has led to the rapid decline to lake water level, the Bosten Lake have also become a brackish lake from freshwater lake because of agricultural drainage salt drainage, at the same time also caused wetlands reed output reduction and the loss of its function.(4) Based on the principle of Geo-statistics show that the oasis agricultural development of water and land resources have significantly affected groundwater in the past decades. On the semi-variogram function analysis showed that the groundwater random variability on the small-scale is replaced by the structural variation on the larger scale space with the agricultural drainage and irrigation groundwater exploitation. And groundwater salinity in the small-scale structural variation has been totally larger scale replaced by the random variation. After decades of irrigation drainage, the area of low salinity is increased and high salinity zoning area be reduced in the Yanqi Basin and the groundwater level decreased. The groundwater level of the temporal and spatial variation in depth greater extent depends on the production of human activities on the exploitation of underground water in the edge of Yanqi Basin. But to the area of human activities in the most concentrated centre of the oasis, the groundwater level is not significantly decrease. At the same time, the groundwater level decreased more serious for the regional of better the quality. Through the study of groundwater Spatial variability of TDS analysis showed that groundwater salinization in the direction of increasing development.(5) The research of salt-water evolution and vegetation distribution show that the bio-diversity depends on the effects of water and salt dual-gradient in the interior oasis irrigation area. The ecosystem are worsen due to slat continued accumulation to Bosten lakefront in Yanqi Basin. The research on the relation of species diversity and groundwater level on the edge of the river that species diversity reduce along with the increasing depth of groundwater less than 1.5 m in depth, depth greater than 2 m, species diversity increased as the groundwater level up in the region groundwater depth less than 3 m. but in the depth between 3-5m, due to the lack of data, further study to determine the best groundwater level for water control in the oasis irrigation area.更多还原