喀斯特地区旅游开发的自然景观保护--以贵州省绥阳县为例   总被引：3，自引：0，他引：3  

孙强  许学工 《地理与地理信息科学》2005,21(4):75-78

该文以贵州省绥阳县为例，针对我国西南喀斯特地区旅游开发中自然环境的特点，探讨溶洞景观的保护、喀斯特地表生态环境保护、水体的保护与综合治理等问题。  相似文献   

不同石漠化程度岩溶峰丛洼地系统景观格局的比较   总被引：16，自引：2，他引：16  

李阳兵  王世杰  容丽 《地理研究》2005,24(3):371-378

利用花江岩溶峡谷区南坡不同石漠化程度的5个独立的岩溶峰丛洼地系统景观要素的实测数据,分析了多样性、优势度、破碎度、分离度等景观格局指标的变化规律及其所指示的生态学意义。结果表明,这些指标在不同峰丛洼地系统都能较好地评价石漠化过程中景观格局的动态变化规律,对分析石漠化土地的发展趋势具有较好的指示意义。但多样性指数、优势度指数、均匀度指数也与各峰丛洼地系统的景观基质有关,在不同石漠化程度的峰丛洼地系统中,反映的景观生态意义是不一样的。景观格局分析不仅强调面积,而且还考虑所研究石漠化土地的空间分布特征(格局)、景观组成特点与石漠化过程的关系和对石漠化的影响,在石漠化程度判定和石漠化指标的研究中景观格局是一个不可忽视的问题。  相似文献   

三江并流世界自然遗产地旅游地质景观成景地质作用初步分析     

王嘉学  明庆忠  杨世瑜  彭秀芬 《云南地理环境研究》2005,17(3):53-56,80

三江并流世界自然遗产地丰富独特的旅游地质景观是多种地质作用与不同成景岩组交互叠加作用的结果。其发育的地层基础主要为碳酸盐成景岩组、变质岩成景岩组、碎屑岩成景岩组以及岩浆岩成景岩组等,典型内力成景地质作用为板块缝合作用、断裂成景作用、变质成景作用,外力作用则主要有河流、冰川、丹霞、地热、喀斯特作用等。  相似文献   

Hillslope erosion measurement—a simple approach to a complex process          下载免费PDF全文

G. R. Hancock  J. B. C. Lowry 《水文研究》2015,29(22):4809-4816

The measurement of hillslope erosion can be a difficult, costly and time‐consuming activity. Many techniques are available, ranging from using environmental tracers, to LiDAR. Erosion measurements using erosion pins are assessed and compared with regional scale erosion data, hillslope data obtained using ¹³⁷Cs and erosion modelling results. The pins produced erosion rates which are within the range determined using ¹³⁷Cs and model data but above that of regional denudation rates. Our findings demonstrate that inexpensive erosion pins can provide reliable data on hillslope erosion. © 2015 Commonwealth of Australia. Hydrological Processes © 2015 John Wiley & Sons Ltd.  相似文献   

中国道路网引起的景观破碎格局及其对保护区的影响     

黄梦娜  马廷 《地球信息科学学报》2019,21(8):1183-1195

道路的修建往往带来景观破碎、生态系统功能受损等后果。有关道路网络的生态影响格局及其影响因素,是当前道路生态学、地理空间分析等领域共同关注的问题。本文利用2015年全国道路网络数据,采用定量空间分析方法,刻画了当前中国铺装道路所引起的陆表景观破碎的格局特征,并分析了道路网络对自然保护区的干扰及与多变量的影响关系。结果表明：① 全国铺装道路的生态影响面积占陆地面积的10%,将陆表切割成3万多个斑块,并呈现小斑块数目众多,大斑块数目较少的分布特点;同时,陆表破碎化程度呈现明显的东西分异规律,空间格局与人口分布、经济发展水平等影响因素的地理分布规律趋同;② 全国约58%的自然保护区受到道路干扰,保护区的受干扰情况存在高等级保护区受干扰弱、低等级保护区次之、国家公园受干扰程度最强等差异特征,且国家公园处于受干扰高于未设保护区域的状态;③ 主要人类活动因素与保护区受干扰程度呈正相关,保护区面积、地形因素与受干扰程度呈负相关,具有面积小、受保护等级低、位于平原地区、气候适宜等特征的保护区更易受到道路干扰,处于已经受到人类活动破坏,生态脆弱的状态。因此,中国道路建设应追求社会发展与生态保护双平衡,同时道路干扰受到自然以及人文要素的共同作用,在相关影响机制研究和生态保护政策制定中应进行综合考虑。  相似文献   

Snow model sensitivity analysis to understand spatial and temporal snow dynamics in a high‐elevation catchment          下载免费PDF全文

Michael Engel  Claudia Notarnicola  Stefano Endrizzi  Giacomo Bertoldi 《水文研究》2017,31(23):4151-4168

In this paper, we addressed a sensitivity analysis of the snow module of the GEOtop2.0 model at point and catchment scale in a small high‐elevation catchment in the Eastern Italian Alps (catchment size: 61 km²). Simulated snow depth and snow water equivalent at the point scale were compared with measured data at four locations from 2009 to 2013. At the catchment scale, simulated snow‐covered area (SCA) was compared with binary snow cover maps derived from moderate‐resolution imaging spectroradiometer (MODIS) and Landsat satellite imagery. Sensitivity analyses were used to assess the effect of different model parameterizations on model performance at both scales and the effect of different thresholds of simulated snow depth on the agreement with MODIS data. Our results at point scale indicated that modifying only the “snow correction factor” resulted in substantial improvements of the snow model and effectively compensated inaccurate winter precipitation by enhancing snow accumulation. SCA inaccuracies at catchment scale during accumulation and melt period were affected little by different snow depth thresholds when using calibrated winter precipitation from point scale. However, inaccuracies were strongly controlled by topographic characteristics and model parameterizations driving snow albedo (“snow ageing coefficient” and “extinction of snow albedo”) during accumulation and melt period. Although highest accuracies (overall accuracy = 1 in 86% of the catchment area) were observed during winter, lower accuracies (overall accuracy < 0.7) occurred during the early accumulation and melt period (in 29% and 23%, respectively), mostly present in areas with grassland and forest, slopes of 20–40°, areas exposed NW or areas with a topographic roughness index of ?0.25 to 0 m. These findings may give recommendations for defining more effective model parameterization strategies and guide future work, in which simulated and MODIS SCA may be combined to generate improved products for SCA monitoring in Alpine catchments.  相似文献   

北部湾典型海岛生态系统服务价值空间异质性对比研究     

田义超  黄远林  张强  陶进  张亚丽  黄鹄  梁铭忠  周国清 《海洋科学》2019,43(2):60-68

基于北部湾海域典型海岛高分1号数据,借助于CART决策树方法,获取了广西北部湾两个典型海岛的景观格局数据,并采用生态系统服务价值计量模型、空间自相关模型及地统计学中的变异函数模型对其生态系统服务价值进行了空间异质性分析。结果表明:团和岛单位面积生态系统服务价值是七星岛的1.08倍,但其变异系数低于七星岛;七星岛由于其地质背景为泥沙岛,景观格局受到人类活动以及自然环境的强烈干扰,趋向于复杂化和破碎化;而团和岛由于所处的外部环境以及自身的地质特征,景观格局呈现出整体斑块化分布状态;团和岛的景观格局主要受到结构性因素的控制,而七星岛则以随机性因素控制为主,选用变程和Moran’s指数来表征其复杂化和破碎化,来决定其优先开发时序,可对前者进行适当开发,而对后者适当进行生态保护;对受到结构性因素影响的岛屿在进行开发时,时序的识别选用变程和Moran’s指数来表征,若变程和Moran’s指数越小,说明海岛整体的景观分布格局趋向于复杂化和破碎化,反之生态系统较好,可进行优先开发。同时本文构建了北部湾海岛生态系统异质性评估与自然资源管理框架,并提出了海岛管理的建议与对策。  相似文献   

Sensitivity of a hydraulic model to channel erosion uncertainty during extreme flooding          下载免费PDF全文

Jefferson S. Wong  Jim E. Freer  Paul D. Bates  David A. Sear  Elisabeth M. Stephens 《水文研究》2015,29(2):261-279

Recent research into flood modelling has primarily concentrated on the simulation of inundation flow without considering the influences of channel morphology. River channels are often represented by a simplified geometry that is implicitly assumed to remain unchanged during flood simulations. However, field evidence demonstrates that significant morphological changes can occur during floods to mobilize the boundary sediments. Despite this, the effect of channel morphology on model results has been largely unexplored. To address this issue, the impact of channel cross‐section geometry and channel long‐profile variability on flood dynamics is examined using an ensemble of a 1D–2D hydraulic model (LISFLOOD‐FP) of the ~1 : 2000 year recurrence interval floods in Cockermouth, UK, within an uncertainty framework. A series of simulated scenarios of channel erosional changes were constructed on the basis of a simple velocity‐based model of critical entrainment. A Monte‐Carlo simulation framework was used to quantify the effects of this channel morphology together with variations in the channel and floodplain roughness coefficients, grain size characteristics and critical shear stress on measures of flood inundation. The results showed that the bed elevation modifications generated by the simplistic equations reflected an approximation of the observed patterns of spatial erosion that enveloped observed erosion depths. The effect of uncertainty on channel long‐profile variability only affected the local flood dynamics and did not significantly affect the friction sensitivity and flood inundation mapping. The results imply that hydraulic models generally do not need to account for within event morphodynamic changes of the type and magnitude of event modelled, as these have a negligible impact that is smaller than other uncertainties, e.g. boundary conditions. Instead, morphodynamic change needs to happen over a series of events to become large enough to change the hydrodynamics of floods in supply limited gravel‐bed rivers such as the one used in this research. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Integrating isolated and riparian wetland modules in the PHYSITEL/HYDROTEL modelling platform: model performance and diagnosis          下载免费PDF全文

Maxime Fossey  Alain N. Rousseau  Fatima Bensalma  Stéphane Savary  Alain Royer 《水文研究》2015,29(22):4683-4702

Mathematical modelling is a well‐accepted framework to evaluate the effects of wetlands on stream flow and watershed hydrology in general. Although the integration of wetland modules into a distributed hydrological model represents a cost‐effective way to make this assessment, the added value brought by landscape‐specific modules to a model's ability to replicate basic hydrograph characteristics remains unclear. The objectives of this paper were the following: (i) to present the adaptation of PHYSITEL (a geographic information system) to parameterize isolated and riparian wetlands; (ii) to describe the integration of specific isolated wetland and riparian wetland modules into HYDROTEL, a distributed hydrological model; and (iii) to evaluate the performance of the updated modelling platform with respect to the capacity of replicating various hydrograph characteristics. To achieve this, two sets of simulations were performed (with and without wetland modules), and the added value was assessed at three river segments of the Becancour River watershed, Quebec, Canada, using six general goodness‐of‐fit indicators and 14 water flow criteria. A sensitivity analysis of the wetland module parameters was performed to characterize their impact on stream flows of the modelled watershed. Results of this study indicate the following: (i) integration of specific wetland modules can slightly increase the capacity of HYDROTEL to replicate basic hydrograph characteristics; and (ii) the updated modelling platform allows for the explicit assessment of the impact of wetlands (e.g. typology and location) on watershed hydrology. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Sensitivity of soil parameters in unsaturated zone modelling and the relation between effective,laboratory and in situ estimates     

J. Mertens  H. Madsen  M. Kristensen  D. Jacques  J. Feyen 《水文研究》2005,19(8):1611-1633

Simulation of soil moisture content requires effective soil hydraulic parameters that are valid at the modelling scale. This study investigates how these parameters can be estimated by inverse modelling using soil moisture measurements at 25 locations at three different depths (at the surface, at 30 and 60 cm depth) on an 80 by 20 m hillslope. The study presents two global sensitivity analyses to investigate the sensitivity in simulated soil moisture content of the different hydraulic parameters used in a one‐dimensional unsaturated zone model based on Richards' equation. For estimation of the effective parameters the shuffled complex evolution algorithm is applied. These estimated parameters are compared to their measured laboratory and in situ equivalents. Soil hydraulic functions were estimated in the laboratory on 100 cm³ undisturbed soil cores collected at 115 locations situated in two horizons in three profile pits along the hillslope. Furthermore, in situ field saturated hydraulic conductivity was estimated at 120 locations using single‐ring pressure infiltrometer measurements. The sensitivity analysis of 13 soil physical parameters (saturated hydraulic conductivity (K_s), saturated moisture content (θ_s), residual moisture content (θ_r), inverse of the air‐entry value (α), van Genuchten shape parameter (n), Averjanov shape parameter (N) for both horizons, and depth (d) from surface to B horizon) in a two‐layer single column model showed that the parameter N is the least sensitive parameter. K_s of both horizons, θ_s of the A horizon and d were found to be the most sensitive parameters. Distributions over all locations of the effective parameters and the distributions of the estimated soil physical parameters from the undisturbed soil samples and the single‐ring pressure infiltrometer estimates were found significantly different at a 5% level for all parameters except for α of the A horizon and K_s and θ_s of the B horizon. Different reasons are discussed to explain these large differences. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献