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基于改進(jìn)力導(dǎo)向模型的生態(tài)節(jié)點(diǎn)布局優(yōu)化

發(fā)布時間:2018-12-12 17:59
【摘要】:在西北干旱半干旱生態(tài)脆弱區(qū),構(gòu)建生態(tài)網(wǎng)絡(luò)可以連接破碎的生境斑塊,提高景觀之間的連通性。而生態(tài)節(jié)點(diǎn)的布局優(yōu)化能夠降低能量損耗,增加穩(wěn)定性,對維持區(qū)域生態(tài)環(huán)境安全穩(wěn)定具有重要意義。以生態(tài)脆弱區(qū)典型縣域磴口縣為研究區(qū),在現(xiàn)有生態(tài)網(wǎng)絡(luò)基礎(chǔ)上,改進(jìn)了HV算法的力導(dǎo)向(force-directed)模型,通過優(yōu)化生態(tài)節(jié)點(diǎn)的布局對生態(tài)網(wǎng)絡(luò)進(jìn)行優(yōu)化。研究結(jié)果表明,在磴口縣選取的局部研究區(qū)內(nèi),與HV算法相比,改進(jìn)force-directed模型優(yōu)化的生態(tài)節(jié)點(diǎn)布局覆蓋率達(dá)到90.79%,提升了4.08個百分點(diǎn);平均聚類系數(shù)升高至0.071,是未改進(jìn)HV算法的1.4倍;分布均勻度降低至2.629,比未改進(jìn)HV算法降低了0.629。通過模型優(yōu)化使得網(wǎng)絡(luò)結(jié)構(gòu)清晰、生態(tài)節(jié)點(diǎn)布局均勻,節(jié)點(diǎn)覆蓋率更高,表明優(yōu)化后生態(tài)網(wǎng)絡(luò)結(jié)構(gòu)更為穩(wěn)定。
[Abstract]:In the arid and semi-arid ecological fragile region of Northwest China, the ecological network can connect the broken habitat patches and improve the connectivity of landscape. The layout optimization of ecological nodes can reduce the energy loss and increase the stability, which is of great significance to maintain the regional ecological environment security and stability. Taking Dengkou County, a typical county in the fragile ecological region, as the research area, based on the existing ecological networks, the force oriented (force-directed) model of the HV algorithm is improved, and the ecological network is optimized by optimizing the layout of the ecological nodes. The results show that in Dengkou County, compared with the HV algorithm, the ecological node layout coverage of the improved force-directed model is 90.79%, which is 4.08% higher than that of the HV algorithm. The average clustering coefficient is increased to 0.071, which is 1.4 times of that of the unimproved HV algorithm, and the distribution uniformity is reduced to 2.629, which is 0.629 less than that of the unimproved HV algorithm. Through the model optimization, the network structure is clear, the distribution of ecological nodes is uniform, and the coverage of nodes is higher, which indicates that the optimized ecological network structure is more stable.
【作者單位】: 北京林業(yè)大學(xué)精準(zhǔn)林業(yè)北京市重點(diǎn)實(shí)驗(yàn)室;佛羅里達(dá)大學(xué)地理系;
【基金】:國家自然科學(xué)基金項(xiàng)目(41371189) “十二五”國家科技支撐計(jì)劃項(xiàng)目(2012BAD16B00)
【分類號】:X171

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