【作者】 黄晨晖；

【导师】 时坚；

【作者基本信息】 广西师范大学 ， 生态学， 2008， 硕士

【副题名】以广西刁江流域为例

【摘要】 近年来土地利用变化及其对环境的影响已成为全球变化研究的前沿和热点,因为土地利用作为地球表层系统最突出的景观标志,能够集中地反映人类活动对生态环境的影响。随着人类活动的日益加强,天然岩溶生态环境遭到极大破坏,其中关于岩溶地下水变化的问题十分突出。人类通过对土地利用的改变从而对脆弱敏感的岩溶水文系统产生了重大的影响。国外Mark Ellaway等许多学者研究了土地利用对岩溶水质的影响,但多集中于单点或地块尺度和某种土地类型导致的水质变化研究,缺乏对流域或更大区域尺度及土地利用组合类型变化对水质影响的研究;而对水量受到的影响也仅仅是局限于森林或草场的变化对岩溶地下水的补给量是增加还是减少以及修建排水系统等人类活动造成含水层补给量较少、泉水枯竭的研究;国内袁道先院士、贾亚男、蒋勇军等科研工作者利用往年的土地利用现状图、地下水资料和监测数据,以流域为研究对象,从时间和空间序列上分析了其研究区内土地利用对岩溶水水质的影响规律,得出岩溶水水质的变化与土地利用的变化表现出动态一致性,并且土地利用对岩溶水水质时空的改变既有有利的一面,也有不利的一面;而对岩溶水水量的变化仅有农业土地利用的转变和过量开采地下水资源引起的水量明显变化的研究。本文在总结前人研究经验和成果的基础上,以广西刁江流域——西南地区典型岩溶流域为研究对象,结合2006年广西地质调查研究院对刁江流域近二十年来水质状况和旱片干旱缺水情况做的初步分析,运用遥感和GIS技术,解译和分析了研究区内土地利用情况,并根据地表水单因子质量现状评价和岩溶水质量综合评价以及水量变化的结果,首次在刁江流域内从时间和空间上研究了土地利用对岩溶水水质水量的影响关系,得出了以下结论:1.从时间上看,研究区内岩溶地下水的水质变化与地表水的变化有很好的一致性,上游众多采、选矿厂对地表水的影响是使上游岩溶水水质某些离子浓度偏高的主要原因,而中下游地区出露的岩溶水点主要受到的是附近居民农田耕作和生产生活的影响。2.同种离子不同浓度值在空间分布上受到土地利用类型的影响主要表现在:Ca2+、HCO3-以较高的浓度集中分布在灌木林、疏林地、裸岩和石砾地土地利用类型当中,Cl-、SO42-、NO3-各自以相对高的浓度值集中于长老乡、下坳乡、板岭乡、拉仁乡一带具开阔连片耕地分布的峰丛谷地中,而板磨小学附近的龙尾下降泉Cl-浓度值较高,乡村公路边的九渡水厂地下河天窗SO42-浓度值较高,说明农耕化肥的使用、密集的人口状况,易于对水质产生影响,但对Al3+、F-等离子浓度值在空间分布上受到土地利用影响的作用途径,还有待于进一步探究。3.分析相关资料和重点对八个岩溶水点2003年与2004年同期出水流量的比较结果,证实研究区内地下河流量有逐年减少的趋势,主要原因是:矿山开采改变了原有的土地利用方式,使植被覆盖率降低,流入地下河系统的尾矿砂又使管道堵塞,降低了有效径流量,导致岩溶出水点流量减少,此外,大量抽取地下水用于灌溉和生产生活也是造成岩溶水量减少的原因之一。4.研究不同土地类型对同一离子浓度的作用程度的结果显示:居民和工矿等特殊用地大于耕地、而耕地又大于林地对离子浓度的影响程度(SO42-浓度现象不明显除外),这说明了人类活动频繁的地区对岩溶水水质的重要影响。5.选取研究区内一小块峰丛洼(谷)地——三只羊地区又做了深入研究,进一步的证明了工矿用地、居民定居点和耕地三种用地类型对岩溶水质质量的影响起主导作用,城乡经济快速发展和人口增加导致建设用地的大幅度增长,为满足生产生活需要大量抽取地下水,都使得岩溶水水量有明显的减少。综上所述,本文找到了影响研究区内岩溶水水质水量变化的主要土地利用类型,对其影响途径和影响程度进行了阐述,这将对改善研究区内人民生产生活用水质量和解决局部区域的干旱缺水问题有着重要的实际意义,也将为实现刁江流域岩溶生态系统的良性循环、资源和环境的保护以及当地经济的可持续发展提供一定的科学依据。更多还原

【Abstract】 In recent years land use change and its impact on the environment has become the forefront and hot spots of global change research, because a land use is the most prominent landscape signs in the Earth’s surface system, it can reflect on human activities on the ecological environment.With increasing human activities, the natural karst ecological environment has been devastated, karst groundwater changes are very outstanding problems. Through land use change the human has produced a significant impact on the vulnerable and sensitive karst hydrological systems.Mark Ellaway, and many foreign scholars studied land use impact on karst groundwater quality, but it more concentrated in researches on a single point or block size and certain type of land led to changes in the water quality, and lacked researches on basin or greater regional scale and type of combined land use changes influenced the water quality; for water quantity, there were only confined that a change of forest or grassland on the supply of karst groundwater is increasing or decreasing and the construction of drainage systems and other human activities resulting in less aquifer recharge and water depletion; in the country Yuan Dao-xian Academicians, Jia Ya-nan, Jiang Yong-jun and other researchers , using previous land use maps, information and groundwater monitoring data, for the basin, in terms of time and space on the sequence, analyzed laws that land use effect karst water quality in respective research areas, the results showed the karst groundwater quality and land use changes were consistent in dynamic changes, and land use changed karst groundwater quality in the time and space had either a positive side or a negative side; for the researches of karst groundwater quantity changes, these only had agricultural land use conversion and excessive exploitation of underground water resources caused significant changes of water quantity.This paper on the basis of previous research experiences and achievements, for study in Diaojiang River Basin in Guangxi - the typical karst watershed of the southwest region, combining with doing the preliminary analysis of the situation by the Guangxi Institute of Geological Survey in 2006 for Diaojiang River Basin water quality in the last 20 years and drought and lack of water, using remote sensing and GIS technology, interpreted and analyzed land use circumstances of the study area, and in accordance with surface water quality evaluation of a single factor and karst groundwater quality integrated evaluation, as well as the results of water quantity changes, in Diaojiang River basin from time and space firstly studied effect connection between the land use and karst groundwater quality and quantity, drew the following conclusions:1. The duration of karst groundwater and surface water quality changes in the study area has a very good consistency, the upper reaches of many mining and mineral processing plant influenced the surface water is the main reason for certain high ion concentration of upstream karst groundwater quality, while in the middle and lower reaches the exposed karst water points are mainly influenced by farmland farming and production and life of the nearby residents.2. In the space distribution different concentrations of the same kind of ion by the impact of land use types mainly show: the higher concentration of Ca2+ and HCO3- centralize distribution in the shrub forest, woodland, uncovered rock and gravel, their relatively high concentration of Cl-, SO42-, NO3- focus on farmland planted with broader distribution of peak-cluster valley in the Zhanglao, Xia’ao, Banling and Laren village,Longwei drop-spring locating primary school of Banmo nearby has a higher concentration of Cl-, Jiudu waterworks skylights of underground river near roadside of village has a higher concentrations of SO42-,this accounts for easy to have an impact on water quality using agricultural fertilizers and owning dense population, but how to influence concentrations of Al3 +, F- and other ions in the spatial distribution under the ways of land use, still await further study.3. Analyze relevant information and focus on comparison results of the water flow of the eight karst groundwater points over the same period of 2003 and 2004, it confirms that in the study area the runoff of underground rivers is decreasing, the main reasons: mining changed the original land use and made the vegetation cover decreased, the tailings inflowing underground river system plug pipeline reduced the effective runoff, resulting in decreasing the flow of karst groundwater points, in addition, a large number extraction of groundwater for irrigation and production and daily life is also one of the reasons for reduction of karst groundwater.4. The extent results of studying the same kind of ion concentration influenced by different land type show: the resident points and mining, and other special used lands are greater than farmland, and farmland is greater than woodland on the impact of the ion concentration levels (except for SO42-concentration, its phenomenon not obvious), this explain the frequent activities of human in the Karst region is an important impact on karst groundwater quality changes.5. In the research region choose a small peak-cluster depression (valley)--three sheep region, doing in-depth studies, and further prove three land types of the mining land and the residents of settlements and arable land play a dominant role of influencing karst groundwater quality; urban and rural population and rapid economic development lead to a significant growth in construction sites, in order to meet production and life needs drew massive groundwater, this makes karst groundwater significantly reduced.Summing up the above, this paper found the main types of land use impacting karst groundwater quality and quantity changes in the research area, explained impact of ways and its impact on the extent, this will have an important practical significance for improving the production and life of people in the region on the quality of water and solving local regional droughty problem of water shortage, and will also provide a scientific basis for achieving virtuous cycle of Diaojiang River Basin Karst Ecosystem, resources and the protection of the environment and the sustainable development of the local economy .更多还原