玛纳斯流域生态需水变化与景观格局的响应关系研究

Study on the Repones Relationship Between Ecological Water Requirement and Landscape Pattern in Manas River Basin

选取西北干旱区水土开发的典型区域玛纳斯河流域为研究对象,基于遥感和GIS技术,与气象站点实测资料相结合,采用FAO56Penman-Monteith法,在ArcGIS建好彭曼模型计算研究区生态需水。利用TM数据解译出1990年、2000年、2010年3期土地利用分类图对玛纳斯河流域进行景观生态学研究,最后尝试性分析生态需水与景观格局关系。结果表明:(1)各区域生态需水变化趋势存在差异,主要表现在山区生态需水增加,平原区生态需水减少。景观格局分析发现2000—2010年中部平原的西面和北面成片出现连通现象,是生态环境恶化较为严重区域。(2)空间上,山区生态耗水量增加,植被多样性指数上升,蔓延度指数下降。时间上,生态耗水量增加,周边的蔓延度指数上升,多样性下降;(3)空间上,绿洲景观格局指数变化与生态需水定额无明显关系,时间上,生态需水定额减小,但在人类活动影响下,周边的景观连通性下降,多样性上升,与山区的结论相反。生态需水定额的减少,将有利于植被的生长,但由于人类活动的影响,生态环境遭到破坏。

The typical region of Manas River Basin, which is dramatic exploitation and use of water and land resources in the arid area of the northwestern of China, was chosen. Based on GIS and RS technology, the observed weather data and FAO56 Penman Motith method, we calculated the ecological water requirement in the study area. We carried out landscape ecology research using three periods of land use patterns abstracted from TM data in 1990, 2000 and 2010 in Manas River Basin. Finally, this paper analyzed the relationship between ecological water requirement and the landscape pattern tentatively. The results showed that： （1） the spatial change trend was different, ecological water requirement would increase in the mountains, and reduce in the plain area, and the connected phenomenon appeared in the oasis of the west and north under landscape pattern analysis during the period from 2000 to 2100, the ecological environment would be destroyed; （2） in the mountains area, the increase of ecological water consumption resulted in the vegetation diversity index increase and contagion index decrease in the space, also, it caused the surrounding contagion index increase and diversity decrease with time; （3） in the oasis, there is no obvious relationship between ecological water demand quota and landscape pattern index in space. The ecological water consumption increased, however, the impact of human activities resulted in the surrounding contagion index decrease and diversity increase with time, which is in contrast to the conclusions of the mountains. Reduction of ecological water require- ment quota would be conducive for the growth of vegetation. Otherwise, the ecological environment would be destroyed because of the influence of human activity.