道路干扰对澜沧江流域景观格局的影响

道路交通在促进人类社会经济发展的同时,也给生态环境带来了诸多影响。研究道路交通的干扰强度、空间格局及其影响,对保护自然环境、维持生态系统健康意义重大。研究基于道路等级、道路所处的环境特征等因素构建道路干扰指数,定量评价了澜沧江流域道路网络的干扰强度,系统分析了流域道路干扰的空间格局特征及其对流域景观的影响。结果表明,澜沧江流域道路网络干扰程度存在明显的区域分异,中游和下游地区明显大于上游地区。流域道路干扰域为边界复杂的不规则多边形,呈现出以离散的强干扰区域为中心,干扰强度向外围逐渐减弱的空间格局。对比不同等级道路干扰域内的景观格局及其变化特征发现,耕地和建设用地等代表人类活动的景观集中分布于道路强干扰区域内,并且强干扰区域内景观组分的变化幅度远大于低干扰区域。从上述分析结果可以看出,道路对其沿线景观格局的变化具有很强的驱动作用,流域道路发展应避开生态环境敏感区域。

Effect of Road Disturbance on Landscape Pattern in the Lancang River Valley

Road plays an important role in the development of economy and society, but it also imposes a threat to environment and ecosystems. Research on such an effect is urgent for environmental protection and ecosystem conservation. This paper quantified the intensity of road network's disturbance in the Lancang River Valley with a road disturbance index, which was established based on the characteristics of a road and its surrounding environment, and then analyzed the spatial pattern of this disturbance and its impact on landscape. The results showed that there was obvious spatial difference of road disturbance intensity throughout the whole Lancang River Valley, the intensity in the middle and lower reaches was far more serious than that of the upper reaches. The road effect-zones were irregular polygons with intricate boundary and taking the spatially scattered severe effect-zones as centers, the disturbance intensity decreased gradually outwards. Comparing landscape patterns and their transformation characteristics among different road effect-zones, it was found out that cropland and built-up area were mainly distributed in severe effect-zones, and the transformation in severe effect-zones was far more violent than that in a weaker one. The above results suggested that road development was an important driving force for landscape change, so sensitive areas should be avoided in the decision-making for new development in the Lancang River Valley.