台湾西南部泥岩土地利用型态与环境劣化趋势之分析

台湾泥岩恶地因其特殊之土壤理化性质及区域微气候的相互恶性循环，衍生生态环境等问题。在以往之35年，裸化面积从1967年的2532hm^2，至2001年11月已扩大为15539hm^2。其表土大量流失、崩塌、河川含砂量激增、植被退化与微气候变异等破坏，更显示泥岩之环境劣化问题。以SPOT卫星影像判识泥岩裸露面积，探讨不同时期之地景变异，并应用地景生态理论量化泥岩地表不同土地利用之空间结构变化，分析地景结构变迁之生态内涵与生态指标意义。因子分析结果其主要变异为多样性因子与形状破碎型因子所影响，而应用马可夫链模式计算出不同时期之土地利用变迁内涵，此结果搭配指标分析可解释泥岩裸露面积与竹林面积皆持续扩大，乃由人为土地利用之活动及植被变迁所引起。     

Decumbent development: Urban sprawl in the Guwahati Metropolitan Area,India

Urban sprawl has become a global phenomenon as an outcome of growing population and rapid urbanization. Previous studies have addressed the rising incidence of uncontrollable urban development, particularly in peri-urban areas of cities, leading to chronic urban sprawl. The city of Guwahati, a million city in north east India, has expanded significantly in recent years. In this article, the links between population and growth of built-up areas were examined using geo-spatial techniques and remotely sensed datasets. The results indicate that the sprawl has accentuated in recent years. The intensity of land use remained uneven due to marked variations in the distribution of built-up areas, plausibly an outcome of unplanned urban growth. If current trends are anything to go by, future urban sprawl could pose serious threats to the vulnerable eco-sensitive and peri-urban areas of Guwahati. Secondary cities have unfortunately received scant attention in urban policy research, and Guwahati, epitomizes urban woes in a developing country.     

Novel shape indices for vector landscape pattern analysis

The formation of an anisotropic landscape is influenced by natural and/or human processes, which can then be inferred on the basis of geometric indices. In this study, two minimal bounding rectangles in consideration of the principles of mechanics (i.e. minimal width bounding (MWB) box and moment bounding (MB) box) were introduced. Based on these boxes, four novel shape indices, namely MBLW (the length-to-width ratio of MB box), PAMBA (area ratio between patch and MB box), PPMBP (perimeter ratio between patch and MB box) and ODI (orientation difference index between MB and MWB boxes), were introduced to capture multiple aspects of landscape features including patch elongation, patch compactness, patch roughness and patch symmetry. Landscape pattern was, thus, quantified by considering both patch directionality and patch shape simultaneously, which is especially suitable for anisotropic landscape analysis. The effectiveness of the new indices were tested with real landscape data consisting of three kinds of saline soil patches (i.e. the elongated shaped slightly saline soil class, the circular or half-moon shaped moderately saline soil, and the large and complex severely saline soil patches). The resulting classification was found to be more accurate and robust than that based on traditional shape complexity indices.     

Modelling coastal land use change by incorporating spatial autocorrelation into cellular automata models

This paper presents a spatial autoregressive (SAR) method-based cellular automata (termed SAR-CA) model to simulate coastal land use change, by incorporating spatial autocorrelation into transition rules. The model captures the spatial relationships between explained and explanatory variables and then integrates them into CA transition rules. A conventional CA model (LogCA) based on logistic regression (LR) was studied as a comparison. These two CA models were applied to simulate urban land use change of coastal regions in Ningbo of China from 2000 to 2015. Compared to the LR method, the SAR model yielded smaller accumulated residuals that showed a random distribution in fitting the CA transition rules. The better-fitting SAR model performed well in simulating urban land use change and scored an overall accuracy of 85.3%, improving on the LogCA model by 3.6%. Landscape metrics showed that the pattern generated by the SAR-CA model has less difference with the observed pattern.     

典型岩溶流域不同地貌类型景观结构分析——以云南小江流域为例

利用2003年小江流域的TM影像，结合实地调查，再根据流域地质分布和地貌发育情况，将流域地貌类型划分为岩溶地貌和非岩溶地貌两个一级类型景观，在此基础上，根据地貌发育程度结合高程情况，将岩溶区又划分为6个岩溶景观，非岩溶地貌分为两个二级类型景观。应用景观生态学原理，并通过Fragstats 3．3软件在流域尺度上计算了一些相关指标。结果表明：岩溶区的景观生态特征总体上体现了其生态环境的特殊性和脆弱性，地表水资源溃乏，土层薄、土壤资源零星分布且易流失，造成未利用地面积大，石漠化现象严重，土地利用程度低的特点。非岩溶区景观生态由于耕地和林地占绝对优势，石漠化面积少，香农多样性指数和均匀度低，景观的异质性较低，结构较为简单。     

Seasonal dynamics of soil CO_2 effluxes with responses to environmental factors in lower subtropical forests of China

Seasonal metrics and environmental responses to forestry soil surface CO2 emission effluxes among three types of lower subtropical forests were consistently monitored over two years with static chamber-gas chromatograph techniques among three types of lower subtropical forests. Results showed that annual CO2 effluxes (S L) reached 3942.20, 3422.36 and 2163.02 CO2 g·m-2·a-1, respectively in the monsoon evergreen broadleaf forest, mixed broadleaf-coniferous forest and coniferous forest. All the three types of forests revealed the same characteristics of seasonal changes with the CO2 effluxes peaking throughout June to August. During this peaking period, the effluxes were 35.9%, 38.1% and 40.2% of the total annual effluxes, respectively. The CO2 emission process responding to the environmental factors displayed significantly different patterns in forestry soils of the three types of forests. The coniferous forest (CF) was more sensitive to temperature than the other two types. The Q10 values were higher, along with greater seasonal variations of the CO2 efflux, indicating that the structurally unique forestry ecosystem has disadvantage against interferences. All the three types of forestry CO2 effluxes showed significant correlation with the soil temperature (Ts), soil water content (Ms) and air pressure (Pa). However, stepwise regression analysis indicated no significant correlation between air pressure and the soil CO2 efflux. With an empirical model to measure soil temperature and water content in 5 cm beneath the soil surface, the CO2 effluxes accounting for 75.7%, 77.8% and 86.5% of the efflux variability respectively in soils of BF, MF and PF were calculated. This model can be better used to evaluate the CO2 emission of soils under water stress and arid or semi-arid conditions.     

黄河流域湿地景观时空演变格局分析

湿地景观的时空演变及其驱动因素研究是湿地生态恢复与保护的重要参考,本文利用1980—2015年7期黄河流域土地利用数据构建黄河流域湿地矢量数据集,基于景观格局指数对黄河流域湿地的时空演变特征进行定量和定性分析;采用转移矩阵对每两个时期湿地资源的转移类型和数量进行计算与分析。研究结果表明,①1980—2015年,黄河流域湿地率为3.5%,其中自然湿地率约为2.0%,即黄河流域的湿地类型以自然湿地为主。②斑块面积结果显示,黄河流域湿地总面积减少了312.74km²,表现为人工湿地增加,自然湿地减少;自然湿地中沼泽湿地呈增加状态,主要是在2005—2010年增加了979.22km²,滩地呈减少状态,减少了1218.19km²,主要发生在1990—1995年和2005—2010年。斑块密度结果显示,随着河渠和滩地受人为活动影响程度的加大,两者的斑块破碎化程度逐渐加大。最大斑块指数结果显示,水田是黄河流域的主导湿地类型,沼泽和湖泊是自然湿地中的主导湿地类型。③黄河流域湿地类型与非湿地之间转换是黄河流域景观转换的主要组成部分,其中沼泽与滩地是面积发生变化的主要湿地类型。     

Detecting multi-scale urban growth patterns and processes in the Algarve region (Southern Portugal)

The importance of urban growth processes and their spatial characteristics has led to a growing interest in monitoring these phenomena. Spatial metrics are widely employed for this purpose, appearing in an increasing number of studies where they are used to characterise growth patterns and their evolution over time. This paper presents an analysis of urban growth patterns using spatial metrics in the Algarve (southern Portugal), an area of considerable urban dynamics associated with tourism. Two datasets were used (CORINE 1:100,000 maps and COS 1:25,000 maps) and two time periods (1990 and 2006–2007) in order to compare the different urban land use patterns detected and their evolution over time. The results show differences in urban land use patterns and associated processes at each scale, with stable land use patterns predominating at the 1:100,000 scale whereas the 1:25,000 scale showed a move towards more dispersed patterns. These results have enabled an assessment of the principal differences in urban growth patterns observed at both scales, and the implications for planning these entail.     

Effects of green space spatial pattern on land surface temperature: Implications for sustainable urban planning and climate change adaptation

The urban heat island (UHI) refers to the phenomenon of higher atmospheric and surface temperatures occurring in urban areas than in the surrounding rural areas. Mitigation of the UHI effects via the configuration of green spaces and sustainable design of urban environments has become an issue of increasing concern under changing climate. In this paper, the effects of the composition and configuration of green space on land surface temperatures (LST) were explored using landscape metrics including percentage of landscape (PLAND), edge density (ED) and patch density (PD). An oasis city of Aksu in Northwestern China was used as a case study. The metrics were calculated by moving window method based on a green space map derived from Landsat Thematic Mapper (TM) imagery, and LST data were retrieved from Landsat TM thermal band. A normalized mutual information measure was employed to investigate the relationship between LST and the spatial pattern of green space. The results showed that while the PLAND is the most important variable that elicits LST dynamics, spatial configuration of green space also has significant effect on LST. Though, the highest normalized mutual information measure was with the PLAND (0.71), it was found that the ED and PD combination is the most deterministic factors of LST than the unique effects of a single variable or the joint effects of PLAND and PD or PLAND and ED. Normalized mutual information measure estimations between LST and PLAND and ED, PLAND and PD and ED and PD were 0.7679, 0.7650 and 0.7832, respectively. A combination of the three factors PLAND, PD and ED explained much of the variance of LST with a normalized mutual information measure of 0.8694. Results from this study can expand our understanding of the relationship between LST and street trees and vegetation, and provide insights for sustainable urban planning and management under changing climate.