西北干旱区景观要素镶嵌结构的分形研究——以黑河流域为例

以黑河流域为区域背景，运用分形理论，定量化地研究西北干旱区景观镶嵌结构的复杂性与稳定性。研究结果表明：（1）各景观要素，按照镶嵌结构的复杂性程度（分维值D）排序，依次分别为：高山草原＞河滩地绿洲＞漫灌戈壁绿洲＞高山寒漠＞土质平地盐漠＞土质平地荒漠＞中山森林＞低滩地绿洲＞中山草原＞高山草甸＞草原化荒漠＞河湖滩地盐漠＞冰川和永久性积雪＞平沙地沙漠＞固定沙丘沙漠＞低平滩地盐漠＞人工绿洲＞荒漠草原＞居民点（城市）＞荒漠戈壁＞荒漠剥蚀戈壁＞高山草甸沼泽＞半固定沙丘沙漠＞流动沙丘沙漠＞丘陵山地荒漠＞高山灌丛草甸＞中山灌丛草原＞中山草甸草原。（2）各景观要素，按照镶嵌结构的稳定性程度（SK）排序，依次分别为：高山草原＞河滩地绿洲＞中山草甸草原＞中山灌丛草原＞高山灌丛草甸＞丘陵山地荒漠＞漫灌戈壁绿洲＞高山寒漠＞流动沙丘沙漠＞半固定沙丘沙漠＞土质平地盐漠＞土质平地荒漠＞中山森林＞低滩地绿洲＞高山草甸沼泽＞中山草原＞荒漠剥蚀戈壁＞高山草甸＞荒漠戈壁＞居民点（城市）＞荒漠草原＞草原化荒漠＞人工绿洲＞低平滩地盐漠＞固定沙丘沙漠＞平沙地沙漠＞河湖滩地盐漠＞冰川和永久性积雪。（3）在各景观要素的镶嵌结构中，高山草原是最复杂，同时也是最稳定的；自然绿洲的复杂性和稳定性都大于人工绿洲。镶嵌结构最为简单的是中山草甸草原。最不稳定的景观要素，恰恰就是维系绿洲生存的关键－冰川和永久性积雪。（4）在沙漠和荒漠化景观中，固定沙丘和平沙地沙漠的复杂性虽然高于半固定沙丘、流动沙丘、荒漠戈壁、荒漠剥蚀及壁及荒漠草原，但是其稳定性却低于半固定沙丘、流动沙丘、荒漠戈壁、荒漠剥蚀戈壁、荒漠草原及草原化荒漠。这就是说，固定沙丘并不稳定。（5）在草原景观中，荒漠草原的稳定性最差。

A Fractal Study on the Mosaic Structure of the Landscape of Northwest China-Taking the Drainage Area of Heihe River as an Example

Taking an example of the drainage area of Heihe River as a setting, studying on the fractal characters of mosaic made of glacier, oasis, desert, and so on with quantitative method, the authors conclude that there are some results as followings: (1) Each landscape factor can be ranked according to the complexity(the fractal dimension D) of the mosaic structure: alpine plain> bottomland oasis > flooding Gobi oasis > alpine arctic desert > soil flat salt desert > soil flat desert > middle-height mountain forest > low bottomland oasis > middle-height mountain plain > alpine meadow > grass-growth desert > river-lake salt desert > glacier and firn > flat sandlot desert >fixed dune > low-flat bottomland salt desert > man-made oasis > desert plain > settlement (urban) > desert Gobi > desert erosion Gobi > alpine meadow swamp >semi-fixed dune > moving dune > hill desert > alpine boskage meadow >middle-height mountain boskage plain > middle-height mountain meadow plain. (2) Each landscape factor can be ranked in the terms of the level of stability(SK): alpine plain > bottomland oasis > middle-height mountain meadow plain > middle-height mountain boskage plain > alpine boskage meadow > hill desert > flooding Gobi oasis > alpine arctic desert > moving dune >semi-fixed dune > soil flat salt desert > soil flat desert > middle-height mountain forest > low bottomland oasis > alpine meadow swamp > middle-height mountain plain > desert erosion Gobi > alpine meadow > desert Gobi > settlement(urban) > desert plain > grass-growth desert > man-made oasis > low flat bottomland salt desert >fixed dune > flat sandlot desert > river-lake bottomland salt desert > glacier and firn. (3) In the middle of the mosaic structure of landscape factors, alpine plain is the most complicated and stablest; the complexity and stability of the natural oasis is greater than that of the man-made oasis. The middle-height mountain meadow plain is the simplest mosaic structure. Glacier and firn, the key of sustaining oasis, are the most unstablest landscape factors. From this we know the truth that we must protect the glacial and firn on the alpine in order to sustain the stability of the oasis ecological system.