玛纳斯河流域景观格局演变特征与驱动机制分析

干旱区景观格局演变特征与驱动机制分析对区域水土资源可持续利用具有重要意义，选择了西北干旱区水土开发的典型区域玛纳斯河流域，基于GIS/RS技术对研究区的1990，2000，2005，2010年TM影像数据进行土地利用分类处理，运用景观生态学的原理分别从类型水平和景观水平上计算出8个景观指数，探讨景观格局变化以及其驱动力。结果表明:（1）研究区草地和未利用土地的优势逐渐减小，耕地的优势逐渐上升，景观多样性升高，优势度下降，趋于分离、破碎化方向发展。（2）人类活动使草地和未利用土地转为耕地，类型转化逐渐由双向转化逐渐趋向于单向转化，草地面积的变化和聚集度指数成线性关系，草地面积每减少1%，聚集度作出减少0.66的响应。（3）降水与气温都有明显的增长，前十年的永久冰川雪地的最大斑块指数和聚集度下降的幅度，均大于后十年，响应了M-K趋势分析“降雨、气温和径流的突变点都集中在1995年左右”。最后提出需要合理规划流域土地利用模式和水资源配置方案，不能挤占生态用水，要实现水土资源的合理开发。

Analysis on Landscape Pattern Change and Driving Mechanism in Manas River Watershed

The arid landscape pattern change and its driving mechanism analysis are of great significance on sustainable utilization of local water and land resources. Typical region of Manas River Watershed, which is dramatic exploitation and use of water and land resources in the arid area of the northwestern of China, was chosen as the study case. Based on the technique of geographical information system (GIS) and remote sensing (RS), land use analysis dispose about TM image data for study area of 1990, 2000, 2005, 2010 were to proceed. The methods of landscape ecology were used to calculate eight landscape indices, respectively, to explore the change of landscape pattern and its driving forces from class level and landscape level. The results show that: (1) the advantages of grassland and unused land in study area decrease gradually, the advantages of arable land increase gradually, landscape diversity elevates, and dominance declines, tending to the change of separation and crushing direction; (2) human activities make grassland and unused land convert to arable land, the type conversion transforms gradually from bidirectional transition to one-way transition, the change of grassland area and aggregation index presents a linear relationship, each 1% reduction in grassland area can make aggregation reduce by 0.656 7; (3) there is a clear growth on precipitation and temperature, the decline range of largest patch index for permanent glacier snow and aggregation in the first decade were all greater than later decade, which responsed the M-K trend analysis of ‘the point mutations of rainfall, temperature and runoff will concentrate around 1995’. Finally, in order to achieve the rational development of water resources, it was suggested that watershed land use patterns and water resources allocation plan should be rationally planned, and ecological water can not be occupied.