科尔沁典型地区流动沙地景观特征分析

Spatial analysis of distribution pattern of the mobile dune patches in the typical regions of Korqin Sandland

本文采用3s技术，对科尔沁典型地区进行取样，分析了在农业生产活动由强～弱～强的梯度变化过程中，流动沙丘斑块空间属性也有相应的变化规律。各级别从斑块的形状特点来看，在以牧业活动为主区域向以农业活动为主区域过渡中，流动沙丘斑块形状趋于复杂。同时，各级斑块面积与分维数的关联分析表明：当斑块面积极小时（〈0．2km^2）时，极易受外界影响而使得形状复杂；当斑块面积大于0．2km^2时，斑块与分维数显著性较差，且为正相关，斑块面积的越大其稳定性越强。

Because the lack of studies on impacts of spatial distribution characteristics of certain patch on ecology process were lack, therefore, this paper sampled and studied the variety of spatial distribution pattern of the mobile dune patches with the grads in the typical regions of Horqin Sandy land with the application of 3S technique. The results showed that the spatial attributes of mobile dune patches had corresponding change law with agricultural activity gradient （strong-weak- strong）. The numbers and areas of mobile dune patches mainly distributed in pastoral activity dominated region （sample 4 to sample 8 ）, reduced from central part to north and south where agricultural activity was dominant. Mobile dunes under different levels presented the same changing trend. On the transition grads from the pastoral activity dominated region to agricultural activity dominated region, the shape of mobile dune patches was complex. At the same time, among the correlative analysis between patch areas and fractal dimension of the mobile dunes at different classes, signifi- cant negative correlation was showed at small patch class （0. 0level） ： patches suffered the impacts easily and the shape become complex at this class when the patch areas were less than 0. 2km2. The positive correlations between the patch areas and the fractal dimensions were not obvious when the patch areas were lager than 0. 2kin2. The patch stability increased along with the patch area increased.