共查询到20条相似文献，搜索用时 593 毫秒
1.
Scientific interpretation of the relationships between agricultural landscape patterns and urbanization is important for ecological planning and management. Ordinary least squares (OLS) regression is the primary statistical method in previous studies. However, this global regression lacks the ability to uncover some local-specific relationships and spatial autocorrelation in model residuals. This study employed geographically weighted regression (GWR) to examine the spatially varying relationships between several urbanization indicators (urbanization intensity index, distance to urban centers and distance to road) and changes in metrics describing agricultural landscape patterns (total area, patch density, perimeter area ratio distribution and aggregation index) at two block scales (5 km and 10 km). Results denoted that GWR was more powerful than OLS in interpreting relationships between agricultural landscape patterns and urbanization, since GWR was characterized by higher adjust R2, lower Akaike Information Criterion values and reduced spatial autocorrelations in model residuals. Character and strength of the relationships identified by GWR varied spatially. In addition, GWR results were scale-dependent and scale effects were particularly significant in three aspects: kernel bandwidth of weight determination, block scale of pattern analysis, and window size of local variance analysis. Homogeneity and heterogeneity in the relationships between agricultural landscape patterns and urbanization were subject to the coupled influences of the three scale effects. We argue that the spatially varying relationships between agricultural landscape patterns and urbanization are not accidental but nearly universal. This study demonstrated that GWR has the potential to provide references for ecological planners and managers to address agricultural landscapes issues at all scales. 相似文献
2.
Analyzing the spatial determinants of urban growth is helpful for urban planning and management. In a case study of urban agglomeration around Hangzhou Bay (China), four landscape metrics (total area, total edge, landscape shape index and aggregation index) were used to describe the landscape characteristics of the urban growth at two block scales (4 km and 7 km) during two temporal intervals (1994–2003 and 2003–2009). Spatial autocorrelation regression was employed to identify the geographic determinants of the urban landscape changes. The results indicated that the urban landscapes became more dominant, unstable, irregular and compact, especially in the centers of cities. These changes exhibited notable spatial variations and spatial autocorrelation at the two block scales. The distances to national and provincial roads influenced the urban pattern changes. The impacts of the urban centers on urban expansion gradually declined with the urbanization progress. The slope factor was the most influential determinant of urban growth. Our study emphasized the importance of considering the autocorrelation and scale effects when analyzing the determinants of urban growth. These findings may help land planners create policies and strategies for future urban development. 相似文献
3.
基于地理加权回归的漫湾库区景观破碎化及影响因子分析 总被引：2，自引：0，他引：2
应用地理加权回归模型分析漫湾库区景观破碎化指数——有效筛网大小与相关因子之间的空间关系。选取的解释变量分别是距道路的距离、距乡村的距离、距河流的距离、坡度。结果表明：大坝修建后4种解释变量与有效筛网大小呈现较显著的正相关性。与线性回归模型相比,地理加权回归模型的拟合效果显著提高。1974~1988年,有效筛网大小对各影响因子最敏感的区域面积呈现显著的时空变化这为确定水电站建设及其他因素对景观破碎化影响的大小,并进一步改善库区景观破碎化的现状提供了依据。 相似文献
4.
5.
山东省人口空间分布格局的多尺度分析 总被引：4，自引：3，他引：1
人口空间分布具有一定的尺度依赖性,从不同尺度上对人口空间分布格局进行分析,可以更确切、真实地揭示人口的空间分布规律,为制定区域发展规划、灾害评价、环境保护等提供科学依据。本文以山东省为研究区,运用空间自相关方法和统计相关分析方法,比较市级、县级、1 km三个尺度上人口分布的空间自相关性及其与环境—经济因子的统计相关性,试图探讨不同尺度下人口的空间分布模式及影响(指示)因素,从不同尺度揭示人口的空间分布格局特征。结果表明:①从不同尺度对人口的空间分布格局进行分析,可以得到从宏观到微观不同详细程度的信息。从市级尺度分析,可以得到山东省整体的人口空间分布特征;从县级尺度分析,可以得到山东省各市内部的人口空间分布特征;从1 km尺度分析,可以得到山东省各县内部的人口空间分布特征。②不同尺度上,人口的空间分布格局特征不同。市级和县级尺度上,人口分布受环境—经济因子的影响表现出与一些因子显著相关,而受空间集聚的作用较小;1 km尺度上,人口分布与环境—经济因子的相关性较小,而主要受空间集聚的作用,在县内部,人口往往集中分布于某一区域,呈现出典型的集聚分布模式。 相似文献
6.
Rapid urbanization leads to losses in arable land; quantitatively analyzing the impact of urbanization on arable land is significant for arable land management. However, changes in arable land due to urbanization with scale and neighborhood effects remains poorly understood at the town scale. In this study, high-resolution historical land use data, landscape metric analysis and spatial regression were integrated to quantify the impacts of urbanization on arable land use change (abandonment and conversion) at spatial scales of 300 m–3300 m using a block size increment of 200 m and at the catchment scale in the town of Jinjing in subtropical central China. Arable land abandonment was the predominant type of arable land change and presented strong spatial autocorrelations at each spatial scale. Arable land was converted to tea fields because agricultural structure transformations were occurring around the urban cores, and the amount of arable land converted to residential land accounted for only a small proportion of the total arable land loss and had no spatial autocorrelation. The significance and robustness of the arable land changes impacted by urbanization had obvious scale effects and strong neighborhood effects in nearby regions. Compared with block scales, the catchment scale is an optimal scale for assessing the influence of urbanization and applying planning policy. Our results highlight the significance of incorporating spatial interactions in urbanization research, which can generate less biased estimations and consequently lead to proper policy implication and recommendations. In addition, multi-scale comparisons are helpful for better understanding the relationships between arable land changes and urbanization and provide further insights into the harmonious development of rural settlements and urban cores to preserve arable land. 相似文献
7.
Accurately mapping the spatial distribution of soil total nitrogen is important to precision agriculture and environmental management. Geostatistical methods have been frequently used for predictive mapping of soil properties. Recently, a local regression method, geographically weighted regression (GWR), got the attention of environmentalists as an alternative in spatial modeling of environmental attributes, due to its capability of incorporating various auxiliary variables with spatially varied correlation coefficients. The objective of this study is to compare GWR and ordinary cokriging (OCK) in predictive mapping of soil total nitrogen (TN) using multiple environmental variables. 353 soil Samples within the surface horizon of 0–20 cm in a study area were collected, and their TN contents were measured for calibrating and validating the GWR and OCK interpolations. The environmental variables finally chosen as auxiliary data include elevation, land use types, and soil types. Results indicate that, although OCK is slightly better than GWR in global accuracy of soil TN prediction (the adjusted R2 for GWR and OCK are 0.5746 and 0.6858, respectively), the soil TN map interpolated by GWR shows many details reflecting the spatial variations of major auxiliary variables while OCK smoothes out almost all local details. Geographically weighted regression could account for both the spatial trend and local variations, whilst OCK had difficulties to capture local variations. It is concluded that GWR is a more promising spatial interpolation method compared to OCK in predicting soil TN and potentially other soil properties, if a suitable set of auxiliary variables are available and selected. 相似文献
8.
《Basin Research》2018,30(2):344-369
The position and mobility of drainage divides is an expression of exogenic landscape forcing and autogenic channel network processes integrated across a range of scales. At the large scale, represented by major rivers and continental drainage divides, the organization of drainage patterns and divide migration reflects the long‐wavelength gradients of the topography, which are exogenically influenced by tectonics, isostasy, and/or dynamic topography. This analysis utilizes long‐wavelength topography synthesized by a low‐pass filter, which provides a novel framework for predicting the direction of divide movement as well as an estimate of the ultimate divide location that is complementary to recent studies that have focused on the χ channel metric. The Gibraltar Arc active plate boundary and Appalachian stable plate interior, two tectonically diverse settings with ongoing drainage system reorganization, are chosen to explore the length scales of exogenic forcings that influence continental drainage divide location and migration. The major watersheds draining both the active‐ and decay‐phase orogens studied here are organized by topographic gradients that are expressed in long‐wavelength low‐pass filtered topography (λ ≥ 100 km). In contrast, the river network and divide location is insensitive to topographic gradients measured over filtered wavelengths <100 km that are set by local crustal structures and rock type. The lag time between exogenic forcing and geomorphic response and feedbacks cause divide migration to be unsteady, and occur through pulses of drainage capture and drainage network reorganization that are recorded in sedimentological, geomorphic, or denudation data. 相似文献
9.
There is a growing requirement for techniques to assess land susceptibility to wind erosion, i.e. land erodibility, over large geographic areas (>104 km2). This requirement stems from a lack of wind erosion research between the field (101 km2) and regional scales, and a need to evaluate the performance of spatially explicit wind erosion models across these scales. This paper addresses this issue by presenting a methodology for monitoring land erodibility at the landscape scale (103 km2). First, we define criteria suitable for evaluating land erodibility based on empirical relationships between soil texture, vegetation cover, geomorphology, and wind erosion. The criteria were used to visually assess land erodibility over long distances (103 km) using vehicle-based transects run through the rangelands of western Queensland, Australia. Application of the data for testing the performance of a spatially explicit land erodibility model (AUSLEM) is then demonstrated by comparing the visual assessments of land erodibility with the model output. The model performed best in the west of the study area in the open rangelands. In regions with higher woody shrub and tree cover the model performance decreases. This highlights the need for research to better parameterise controls on erodibility in semi-arid landscapes consisting of forested and rangeland mosaics. 相似文献
10.
土壤碳库研究中土壤数据从矢量到栅格的等精度转换 总被引：1，自引：1，他引：0
矢量数据转换成栅格数据是多数区域土壤碳库研究中数据准备的关键步骤。本研究以太湖地区1:5万、1:50万、1:400万3个比例尺土壤矢量数据库为基础,分别转成不同分辨率的栅格数据;基于不同比例尺和栅格分辨率数据,研究水稻土表层(0～20cm)的土壤类型数量、面积、有机碳储量以及有机碳密度变化,并以矢量数据获得的这4个指标为基准,用相对变异百分数(VIV)来判别不同栅格数据与其对应比例尺土壤矢量数据之间的精度差异。结果表明,在4个指标的|VIV|<1%前提下,3个比例尺矢量数据分别转换成0.2km×0.2km、1km×1km、9km×9km的栅格数据,既保证数据转换过程中精度要求,又避免了数据冗余。土壤数据比例尺与栅格分辨率等精度转换对应关系可描述为y=0.0225x-0.01233(R2=0.999),对区域土壤碳循环研究具有重要参考价值。 相似文献
11.
城市景观格局尺度效应的空间统计规律--以上海中心城区为例 总被引：33，自引：3，他引：30
以上海市外环以内的中心城区为区域背景,基于SPOT全色波段遥感影像数据和GIS技术,运用空间统计分析方法,研究城市景观格局的空间尺度效应。研究结果表明:(1)城市景观格局的空间自相关性具有显著的尺度依赖性。Moran指数I与Geary系数c对粒度变化的敏感点相同,均为50m。(2)城市景观形态具有分形特征,各类景观斑块的分维数对粒度变化的响应不同,它们随着粒度的变化呈非线性变化趋势;在粒度较小时,各类景观斑块之间的分维数差异较大,而随着粒度的增大,其分维数之间的差异逐渐缩小。(3)城市景观多样性格局,与空间区位及人类活动的空间格局息息相关。在城市中心,主导型景观是经济效益较高的商业文化景观,并且景观斑块聚集度、破碎度大;经济效益较低的农业景观分布在城市边缘区,而且景观类型单一,斑块面积较大,破碎度较小;在由城市中心向边缘过渡的中间地带,景观类型多样,空间格局复杂。(4)景观多样性具有尺度依赖性。随着幅度的增加,景观多样性指数逐渐增大,多样性的空间格局也显著变化。在0.5km幅度下,多样性指数的最大值出现在市中心,从市中心向外呈现高低起伏的环状模式扩展,随着幅度增加,多样性指数的高值区向景观类型变化最剧烈的城乡过渡地带转移。(5)景观多样性的空间变异也具有明显的尺度依赖性。在较 相似文献
12.
A suitable spatial scale needs to be selected in geographical and landscape ecological research, and this requires great consideration as different scales have profound effect on derived landscape spatial patterns. Numerous studies have investigated the effects of different scales on landscape metrics using simulated patterns, but few have been conducted to compare different data sources with variable scale for regional- and landscape-scale assessments. Possibly this has occurred because researchers have been prone to use the best available source, a well-known standard, and easiest to use. This study was conducted to assess the impact of input data resolution on values of landscape pattern metrics in four landscapes at scales 1:10 000, 1:50 000 and 1:100 000. The aim was to determine the applicability of three data sources for thematic models in landscape pattern analyses in the Eastern Baltic region. We found that the utility of CORINE Land Cover data for comprehensive structural assessment in mosaic-type landscapes was very limited, as the level of cartographic generalization excluded many small and linear landscape structure elements with potentially high importance for landscape functioning, such as habitat continuity. We also found that actual area harvested using clearcuts was considerably higher than shown in CORINE data, due to clearcuts size being much smaller than the minimum mapping unit. In the light of this, we suggest using data with spatial resolution corresponding to a cartographic scale of at least 1:50 000, in cases when spatial patches have size up to 25 ha. 相似文献
13.
伊犁河三角洲景观结构的影响机制研究 总被引：1，自引：0，他引：1
在遥感和水文数据的支持下,根据伊犁河三角洲作为典型的中亚干旱区内陆河流域尾闾区域特点,确定了伊犁河三角洲的景观分类系统。通过采用景观结构梯度分析法、景观干扰度指数和景观Kappa指数等方法,系统地分析了近32 a（1975-2007）伊犁河三角洲景观结构的时空演变特征,并对景观结构的影响机制做了充分地探讨。结果表明：（1）沿着一定的地形梯度和水文梯度,伊犁河三角洲流域景观表现出特殊的纵向结构、横向结构的梯度特征和景观内部特征,与地表水直接关联的景观类型表现尤为明显,如湖泊、沼泽、漫滩。（2）在人为活动和自然环境的双重影响下,近32 a伊犁河三角洲景观结构的空间变化具有一定的周期性和不稳定性,主要体现为景观类型面积和空间位置的变化,其中以湿地景观类型的变化最为显著。（3）生态干扰对景观结构的影响因景观类型的不同存在显著的差异性和时空变异性,以湖泊和沼泽受干扰作用最为明显。高、中、低三种干扰强度区域的空间分布及面积变化同样具有一定的周期性和不稳定性。（4）水利工程建设和自然环境是影响伊犁河三角洲景观结构的主要驱动力。水利工程对伊犁河的拦蓄引起景观结构变化的作用最为深远,它通过改变三角洲上游的水文情势直接影响整个区域的景观结构。而自然环境因素中的地形和水文条件主要影响湿地景观类型的时空分布,气候因子则直接影响河川径流量。 相似文献
14.
Jane Southworth Graeme S. Cumming Matt Marsik Michael W. Binford 《The Professional geographer》2006,58(4):406-420
Anthropogenic, ecological, and land‐surface processes interact in landscapes at multiple spatial and temporal scales to create characteristic patterns. The relationships between temporally and spatially varying processes and patterns are poorly understood because of the lack of spatiotemporal observations of real landscapes over significant stretches of time. We report a new method for observing joint spatiotemporal landscape variation over large areas by analyzing multitemporal Landsat data. We calculate the spatiotemporal variation of the Normalized Difference Vegetation Index (NDVI) in the area covered by one Landsat scene footprint in north central Florida, over spatial windows of 104–108 m2 and time steps of two to sixteen years. The correlations, slopes, and intercepts of spatial versus temporal regressions in the real landscape all differ significantly from results obtained using a null model of a randomized landscape. Spatial variances calculated within windows of 105–107 m2 had the strongest relationships with temporal variances (regressions with both larger and smaller windows had lower coefficients of determination), and the relationships were stronger with longer time steps. Slopes and y‐intercepts increased with window size and decreased with increased time step. The spatial and temporal scales at which NDVI signals are most strongly related may be the characteristic scales of the processes that most strongly determine landscape patterns. For example, the important time and space windows correspond with areas and timing of fires and tree plantation harvests. Observations of landscape dynamics will be most effective if conducted at the characteristic scales of the processes, and our approach may provide a tool for determining those scales. 相似文献
15.
Cristian Echeverría Adrian NewtonLaura Nahuelhual David CoomesJosé María Rey-Benayas 《Applied geography (Sevenoaks, England)》2012,32(2):822-831
A comprehensive understanding of the patterns that occur as human processes transform landscapes is necessary for sustainable development. We provide new evidence on how landscapes change by analysing the spatial patterns of human processes in three forest landscapes in southern Chile at different states of alteration (40%-90% of old-growth forest loss). Three phases of landscape alteration are distinguished. In Phase I (40%-65% of old-growth forest loss), deforestation rates are < 1% yr−1, forests are increasingly degraded, and clearance for pastureland is concentrated on deeper soils. In Phase II (65%-80%), deforestation reaches its maximum rate of 1-1.5% yr−1, with clearance for pastureland being the main human process, creating a landscape dominated by disturbed forest and shrubland. In this phase, clearance for pastureland is the primary driver of change, with pastures expanding onto poorer soils in more spatially aggregated patterns. In Phase III (80%-90%), deforestation rates are again relatively low (<1% yr−1) and forest regrowth is observed on marginal lands. During this phase, clearance is the dominant process and pastureland is the main land cover. As a forest landscape is transformed, the extent and intensity of human processes vary according to the existing state of landscape alteration, resulting in distinctive landscape patterns in each phase. A relationship between spatial patterns of land cover and human-related processes has been identified along the gradient of landscape alteration. This integrative framework can potentially provide insights into the patterns and processes of dynamic landscapes in other areas subjected to intensifying human use. 相似文献
16.
基于变化轨迹分析方法的生态用地流失空间关联研究 总被引：3，自引：0，他引：3
针对现有研究割裂了生态用地流失这一基本变化过程的不足,本文基于变化轨迹分析方法,从过程完整性角度探求了京津冀城市群地区生态用地流失的空间关联特征。结果表明：① 京津冀城市群地区土地利用变化主要表现为林地、草地、水域和耕地的流失,流失面积的40%转为人工表面;② 林地、草地和水域流失的空间自相关性随空间尺度增大而增强,7 km×7 km空间尺度上3种生态用地流失空间正相关性较强,且随距离阈值增加而降低;③ 距离阈值为10 km时,林地、草地流失高发区集中分布在京津冀西北部地区,水域流失高发区集中分布在东部渤海湾附近,生态环境保护应从京津冀协同发展角度,打破区域发展不均衡,促进京津冀城市群全面发展。 相似文献
17.
AutoLogistic 方法在土地利用格局模拟中的应用 —— 以张家界市永定区为例 总被引：7，自引：1，他引：6
土地利用/ 土地覆被变化(LUCC) 是当前研究全球变化的重要内容, 而区域土地利用 格局模拟是LUCC 研究的核心内容之一。以张家界市永定区为研究单元, 根据由2005 年土地 利用现状图和数字高程模型数据源得到的土地利用、地形、河流以及道路等空间数据, 对区 域土地利用类型空间格局的空间自相关性特征进行了建模研究, 并通过在传统Logistic 模型 中引入描述空间自相关性的成份, 实现了能够考虑自相关性因素的回归分析模型 (AutoLogistic 模型), 同时应用该模型对区域土地利用格局进行了模拟和分析。结果显示, 通 过与没有考虑空间自相关性的回归模型(传统Logistic 模型) 相比较, 该模型显示了更好的拟 合优度和更高的拟合准确率(耕地、林地、建设用地及未利用地的ROC 值分别从0.851、 0.913、0.877 和0.852 提高到0.893、0.940、0.907 和0.863)。研究结果说明了基于 AutoLogistic 方法的土地利用格局的相关性建模在一定意义上是合理的。同时研究结果也可以 为永定区及其相似地区的土地利用规划决策提供更为科学的依据。 相似文献
18.
Soil erosion is a global environmental problem, and anthropogenic fallout radionuclides offer a promising tool for describing and quantifying soil redistribution on decadal time scales. To date, applications of radioactive fallout to trace upland sediment transport have been developed primarily on lands disturbed by agriculture, grazing, and logging. Here we use 137Cs to characterize and quantify soil erosion at the Konza Prairie Long-Term Ecological Research (LTER) site, an undisturbed grassland in northeastern Kansas. We report on the small scale (< 10 m) and landscape scale (10 to 1000 m) distribution of fallout 137Cs, and show significant variability in the concentrations and amounts of 137Cs in soils at our site. 137Cs soil concentrations and amounts typically vary by 10% to 30% on small scales, which most likely represents the spatial heterogeneity of the depositional processes. Landscape scale variability of soil 137Cs was significantly higher than small scale variability. Most notably, soils collected on convex (divergent) landforms had 137Cs inventories of 2500 to 3000 Bq m− 2, which is consistent with the expected atmospheric inputs to the study area during the 1950s and 1960s. Concave landforms, however, had statistically lower inventories of 1800 to 2300 Bq m− 2. The distribution of 137Cs on this undisturbed landscape contrasts significantly with distributions observed across disturbed sites, which generally have accumulations of radioactive fallout in valley bottoms. Because the upslope contributing area at each sampling point had a significant negative correlation with the soil inventory of 137Cs, we suggest that overland flow in convergent areas dominates soil erosion at Konza on time scales of decades. Very few points on our landscape had 137Cs inventories significantly above that which would be predicted from direct deposition of 137Cs on the soil surface; we conclude therefore that there is little net sediment storage on this undisturbed landscape. 相似文献
19.
西南岩溶山地乡村景观格局与石漠化调控展望 总被引：3，自引：0，他引：3
西南岩溶山地乡村景观格局石漠化过程的生态认识落后于生态治理措施。面对国家需求,优化乡村景观格 局对石漠化发生过程的调控,未来优先研究领域：⑴识别岩溶山地乡村景观格局的转换、渐变和基本不变的层次 性,测算不同尺度下乡村景观类型及其空间组合的贡献;⑵认识不同类型乡村景观空间分布的生态学意义及其对 区域石漠化整体程度的影响,找出不同乡村景观演化格局下的石漠化效应;⑶厘定岩溶山地高强度人类活动及其 所诱导的乡村景观格局演化对石漠化的作用效应,构建乡村景观石漠化的成因框架;⑷探讨乡村景观格局制约下 有利于石漠化土地恢复的格局优化模拟,丰富人们对岩溶山地乡村石漠化发生过程的理解和认识。 相似文献
20.
We evaluated nest site selection at two spatial scales (microsite, territory) and reproductive success of Western Burrowing Owls (Athene cunicularia hypugaea) at three spatial scales (microsite, territory, landscape) in the eastern Mojave Desert. We used binary logistic regression within an information-theoretic approach to assess factors influencing nest site choice and nesting success. Microsite-scale variables favored by owls included burrows excavated by desert tortoise (Gopherus agassizii), burrows with a large mound of excavated soil at the entrance, and a greater number of satellite burrows within 5 m of the nest burrow. At the territory scale, owls preferred patches with greater cover of creosote bush (Larrea tridentata) within 50 m of the nest burrow. An interaction between the presence or absence of a calcic soil horizon layer over the top of the burrow (microsite) and the number of burrows within 50 m (territory) influenced nest site choice. Nesting success was influenced by a greater number of burrows within 5 m of the nest burrow. Total cool season precipitation was a predictor of nesting success at the landscape scale. Conservation strategies can rely on management of habitat for favored and productive nesting sites for this declining species. 相似文献