AutoPaCA:耦合过程-模式的城镇空间增长模拟模型

理解城镇增长过程、模式、机理并预判未来发展趋势,对优化城镇空间布局,促进城市可持续发展有重要意义。元胞自动机模型（Cellular Automata, CA）是研究城镇增长过程、模式的有效技术手段,但传统CA模型对城镇增长过程和空间模式的协同考虑不足。本研究构建了基于斑块（Patch）的城镇CA模型AutoPaCA,实现对城镇增长过程及空间模式的协同表征和精细控制,将城镇增长过程分为边缘增长和跳跃增长两种形式,并实现了对不同形式下城镇斑块位置、形状和面积大小的精细控制,同时考虑城镇空间模式的集聚性、整体形态及空间约束。此外,还提出使用景观格局分析法分析历史时期城镇增长过程和模式,并结合遗传算法实现对模型参数的地域化自动校正,降低人为主观因素对模拟结果的影响。将模型应用于长沙市1995—2035年的城镇增长模拟与多情景分析。结果表明,构建的AutoPaCA模型可以取得较好的模型精度,200次模拟结果的互异邻域相似性指数均值达到0.486;在生态保护情景下,长沙市城市内部生态结构保存完好,且表现出更为明显的长株潭一体化趋势,说明本研究提出的AutoPaCA模型及参数校正方法是有效的。     

海湾型半城市化地区空间形态演化模拟

元胞自动机（CA）是模拟城市土地利用演变过程的有效工具,转换规则和元胞邻域是元胞模型的核心。综合考虑元胞邻域的距离衰减效应,基于模拟退火算法（SA）挖掘最优的转换规则,文章构建了一种考虑邻域衰减的城市演化模型（SA-NDCA）。模型以负幂指数函数作为元胞邻域的衰减曲线表示元胞邻域的距离衰减效应;运用模拟退火优化算法计算城市CA模型模拟结果与样本点的累积差异,在目标解空间快速搜索以提取最优的转换规则;最后以厦门市半城市化地区为研究案例,模拟了研究区域1995―2010年期间的城市空间形态演化,通过混淆矩阵和Kappa系数评价了模型的模拟精度,1995―2010年期间的建设用地模拟精度为68.5%,总体精度达到86.2%,Kappa系数达到66.3,取得了较好的模拟效果。利用提出的SA-NDCA模型,成功模拟了研究区2010―2020年期间的城市空间形态演化,结果显示,所预测的演化情景与中国当前实施的新型城镇化战略十分契合。     

岩石破裂过程的自组织临界特征初探

自组织临界状态。是广延耗散动力学系统所普遍具有的行为特征。实验表明，岩石破裂过程也具有自组织临界特征。本文运用数学－力学分析和计算机模拟等手段。研究了岩石破裂过程中所现出的累进性破坏及无序向有序演化等特征的内在机理，从而加深了岩石破裂失稳定过程机制的认识。     

基于RS和GIS的生态足迹分析

1IntroductionIn recent years the ecological footprint (EF), originally developed by Wackernagel and Rees in the mid-1990s (Wackernagel and Rees W, 1996; 1997), has gained much attention in Ecological Economics. This method tracks natural resources consump…     

内嵌空间聚类算法的分区地理元胞自动机建模与应用

传统的地理元胞自动机(Geo-Cellular Automata;GeoCA)模型,大多采用统一的转换规则驱动元胞空间内的所有元胞进行演变。然而,许多地理现象都存在着空间异质性,统一的元胞转换规则忽略了空间异质性的存在。针对这一问题,本文提出了空间聚类的分区地理元胞自动机模型,采用空间聚类算法对元胞空间进行分区,对不同的分区分别求取转换规则,以此来提高地理元胞自动机的模拟精度。以杭州市为案例区,采用本文提出的空间聚类的分区地理元胞自动机模型,对研究区2000-2005年的城市用地变化进行了模拟。结果表明:与采用统一转换规则的GeoCA相比,引入空间聚类算法的分区GeoCA具有较高的模拟精度,尤其是在空间形态和整体结构上,具有较好的模拟效果。     

改进的案例推理CA模型及土地覆盖变化模拟

对基于案例推理的元胞自动机模型(CBR-CA)进行改进,将各类别的宏观转移概率添加到目标函数中,体现各类别的转变特征,并增加时间权重来确定转移概率,实现时间尺度上的模拟;由于土地覆盖变化的多样性和空间结构的复杂性,利用Monte Carlo(M-C)法确定土地覆盖的最终转换类别。选择黄河源区为试验区,利用1977年、1985年土地覆盖数据建立原始案例库,模拟了该区域1995年、2000年和2006年的土地覆盖变化,模拟的各类别转换的数量精度与实际相吻合,各年份的总体误差分别为0.002%、0.012%和0.005%,空间位置精度总体在70%以上,并进行未来土地覆盖情景预测。该模型可用于多类别、长时间序列区域土地覆盖变化的模拟与预测。     

A new tool for modeling dune field evolution based on an accessible, GUI version of the Werner dune model

Research into aeolian dune form and dynamics has benefited from simple and abstract cellular automata computer models. Many of these models are based upon a seminal framework proposed by Werner (1995). Unfortunately, most versions of this model are not publicly available or are not provided in a format that promotes widespread use. In our view, this hinders progress in linking model simulations to empirical data (and vice versa). To this end, we introduce an accessible, graphical user interface (GUI) version of the Werner model. The novelty of this contribution is that it provides a simple interface and detailed instructions that encourage widespread use and extension of the Werner dune model for research and training purposes. By lowering barriers for researchers to develop and test hypotheses about aeolian dune and dune field patterns, this release addresses recent calls to improve access to earth surface models.     

Exploring the impacts of future tourism development on land use/cover changes

Land use/cover changes (LUCC) are central to tourism because land is used in multiple ways as a resource for tourism-focused activities. Tourism is essentially a geographical phenomenon, encompassing the movement and flow of people (seen as the demand side) and spatial distribution patterns relating to land use consumption (seen as the supply side). However, the impacts of tourism on LUCC are difficult to track and monitor. Contributing factors of this problem include a lack of empirical studies, shortage of micro-level LUCC datasets, and scarce methodological frameworks which can be used for assessments. This paper aims to provide a LUCC modelling approach in order to explore the impacts of tourism development on built-up areas. We developed a Cellular automata model (CA) which integrates Markovian transition probabilities and logistic regression transition suitability maps. LUCC rules for tourism development are framed within the national land use policy guidelines for the development of new tourism accommodation establishments (TAE). This primarily takes into consideration land cover compatibility and the proposed development's proximity to the coastline.Three scenarios were established to explore the impacts of tourism development in LUCC for the year 2020 in a Portuguese coastal region: business as usual (BAU); tourism trends (TOUR); and natural restrictions (NATR). TOUR results indicate that the tourism and urban land use/cover growth is higher and focuses heavily on the coastal region (within 5,000 m) when compared to the other scenarios. The overall results for BAU and NATR show a general convergence with the land use policy guidelines in terms of tourism nucleation and new TAE distance to the coastline.     

Cellular energy allocation in mussels (Mytilus galloprovincialis) from the stratified estuary as a physiological biomarker

This study demonstrates the usefulness of cellular energy allocation (CEA) evaluations as a physiological biomarker to infer the occurrence of natural stress in native populations of mussels inhabiting the stratified estuary (Krka River estuary, Croatia). Sampling sites were selected based on their differences in the salinity and temperature. The CEA value was calculated as a ratio between available energy (E_a) and energy consumption (E_c). Generally, higher values of E_a were recorded in June than in November, which were especially evident in the storage components (carbohydrates and lipids), while the constitutive component (proteins) remained relatively constant. The highest E_c was recorded in mussels at estuarine site compared to coastal site, which may be caused by the energetically costly maintenance of osmotic balance. Decrease in CEA recorded in estuarine mussels may ultimately result in a lower amount of energy available for growth, reproduction, or defence against other stresses (e.g. pollution).     

Isolation, characterization of Rhodococcus sp. P14 capable of degrading high-molecular-weight polycyclic aromatic hydrocarbons and aliphatic hydrocarbons

Rhodococcus sp. P14 was isolated from crude oil-contaminated sediments. This strain was capable of utilizing three to five rings polycyclic aromatic hydrocarbons (PAHs) including phenanthrene (Phe), pyrene (Pyr), and benzo[a]pyrene (BaP) as a sole carbon and energy source. After cultivated with 50mg/L of each PAH, strain P14 removed 43% Phe, 34% Pyr and 30% BaP in 30 d. Four different hydroxyphenanthrene products derived from Phe by strain P14 (1,2,3,4-hydroxyphenanthrene) were detected using SPME-GC-MS. Strain P14 also was capable of degrading mineral oil with n-alkanes of C17 to C21 carbon chain length. Compared with glucose-grown cells, PAHs-grown cells had decreased contents of shorter-chain length fatty acids (≤ C16:0), increased contents of C18:0, Me-C19:0 and disappeared odd-number carbon chain fatty acids. The contents of unsaturated C19:1, Me-C19:0 increased and C18:0 decreased in mineral oil-grown cells. At the same time, the strain P14 tended to float when cultivated in mineral oil-supplemented liquid medium. The degradation capability of P14 to alkane and PAHs and its floating characteristics will be very helpful for future's application in oil-spill bioremediation.