中国避暑型与避寒型宜人气候的分布特征及差异     

邓粒子  保继刚 《地理研究》2020,39(1):41-52

宜人气候可以分为避暑型和避寒型两种类型,但现有研究鲜有关注国内两类气候的分布特征及差异。本文采用1981—2010年2132个国家气象观测站数据,基于温湿指数、风寒指数和着衣指数计算各个气象站点的气候综合舒适指数,结合协同克里金空间插值方法对全国避暑型和避寒型宜人气候的分布特征进行了研究,并对两类气候的地域差异进行了分析。结果表明：① 中国避暑型气候区包括40°N以北的西北边疆和东北地区、西北中部地区及西南地区三大集中分布区。中国避寒型气候区集中分布在北回归线以南的低纬地区。② 国内夏冬两季的气候不舒适地域广阔,包括环渤海、长三角等经济发达、人口稠密地区,避暑型与避寒型气候资源的开发潜力显著。③ 两类宜人气候呈现明显的地域分离特征,拥有避暑和避寒双重属性的地方极少。④ 国内避寒型气候是稀缺资源,具有垄断性特征;而避暑型气候相对分布广泛,是一种相对遍在性资源。本文不仅丰富了宜人气候分布特征研究的理论成果,而且可为地方气候资源的旅游开发提供科学依据。  相似文献   

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  

刘金雅  汪东川  孙然好  汪翡翠  胡炳旭  陈俊合  孙志超 《地理研究》2020,39(1):103-114

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   

重庆市主体功能区识别的主导因素与空间稳定性约束机理     

汪洋  王力力  祁鹏卫  刘志海 《地理学报》2019,74(1):44-62

主体功能区规划已上升为国家制度和战略,对中国长期空间发展格局优化与再组织将发挥积极的引导和约束作用。从地域性角度出发,探寻主体功能区发生性（形成与演化）和反馈性（识别与规划）时空机理与规律是地理学具有时代意义的重要科学问题。以重庆市为例,通过国土空间开发条件综合评价,识别了主体功能区划分的适宜性空间格局。基于对西南山区发展约束条件的基本认识,提出了地域主体功能空间分异的主导性约束假设,设定地形和区位为原生性主导因素,验证了其与区划指标系统的定量关联性,以此为基础解析了主导因素约束机理并提出了地域主体功能区的空间稳定性机制。研究发现：① 开发与保护适宜性识别结果的格局指向清晰。城市化适宜的区域主要集中于都市区和部分周边区县,区域副中心（万州和黔江）适宜性也相对较高。生态保护适宜的区域集中于渝东北秦巴山区及部分三峡库区区县,同时包括渝东南武陵山区所在区县。② 地形和区位因子在本区域对主体功能区的识别与形成具有主导约束作用。回归分析显示,主体功能区划指标与地形因子相关性水平达到显著的超过70%,区位因子超过40%;两者综合后与区划标志变量（A、B指数）的相线性相关拟合度R²均超过0.8;地理探测器发现,地形和区位因子对区划指标的约束性分别有9个和7个达到0.05显著性水平,对A、B指数的解释度分别约为70%和60%,两者叠加后,约束水平全部达到显著,对A、B指数的解释度在90%左右。③ 空间稳定性机制表现为两个方面,其一是基于主导因素约束的稳定性传递机制,称为客观稳定性;其二是基于指标体系的局域相对性和算法的内部抵消机制,称为主观稳定性。两种机制的协同性验证了区划技术系统的地域适应性和科学性。  相似文献   

不同插值方法在海域气象参数估算中的可靠性评价          下载免费PDF全文

艾葳  万继敏  崇元 《海洋技术学报》2019,38(2)

海域条件下的气象观测具有数据稀少、变化大且观测站点分布不均的特点,其插值精度受插值方法影响较大。首先对常规插值方法进行理论分析,进而选取了反距离加权法、克里金法和样条函数法三种插值方法进行了插值实验和精度分析。根据渤海湾某区域的气象历史数据,采用不同方法绘制了温度、压强和湿度的插值平面图,并基于交叉验证的方式对各插值方法进行了对比,给出了不同方法的插值估算可靠性评价。结果表明:温度、压强和湿度的插值精度均是基于反距离加权法的插值结果最优(MAE_(温度)=2.42,RMSE_(温度)=1.92,MAE_(压强)=2.05,RMSE_(压强)=1.30,MAE_(湿度)=11.394, RMSE_(压强)=6.43),同时基于反距离加权法的图形绘制可视化效果也要优于其他两种方法。研究结果可为海域气象参数估算提供理论和实践依据。  相似文献   

Beerkan multi-runs for characterizing water infiltration and spatial variability of soil hydraulic properties across scales   总被引：1，自引：1，他引：0  

Laurent Lassabatere  Simone Di Prima  Rafael Angulo-Jaramillo  Saskia Keesstra  David Salesa 《水文科学杂志》2019,64(2):165-178

A method is presented for characterizing the spatial variability of water infiltration and soil hydraulic properties at the transect and field scales. The method involves monitoring a set of 10 Beerkan runs distributed over a 1-m length of soil, and running BEST (Beerkan estimation of soil transfer parameters) methods to derive hydraulic parameters. The Beerkan multi-runs (BMR) method provides a significant amount of data at the transect scale, allowing the determination of correlations between water infiltration variables and hydraulic parameters, and the detection of specific runs affected by preferential flow or water repellence. The realization of several BMRs at several transects on the same site allows comparison of the variation between locations (spatial variability at the field scale) and at the transect scale (spatial variability at the metre scale), using analysis of variance. From the results, we determined the spatial variability of water infiltration and hydraulic parameters as well as its characteristic scale (transect versus field).  相似文献   

The small-scale dynamo in a spectral representation     

E. Yushkov  A. Lukin  D. Sokoloff  P. Frick 《地球物理与天体物理流体动力学》2019,113(1-2):184-198

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Spatiotemporal variability in hydrochemistry of shallow groundwater in a small pre‐alpine catchment: The importance of landscape elements     

Leonie Kiewiet  Jana von Freyberg  H.J. van Meerveld 《水文研究》2019,33(19):2502-2522

Topography and landscape characteristics affect the storage and release of water and, thus, groundwater dynamics and chemistry. Quantification of catchment scale variability in groundwater chemistry and groundwater dynamics may therefore help to delineate different groundwater types and improve our understanding of which parts of the catchment contribute to streamflow. We sampled shallow groundwater from 34 to 47 wells and streamflow at seven locations in a 20‐ha steep mountainous catchment in the Swiss pre‐Alps, during nine baseflow snapshot campaigns. The spatial variability in electrical conductivity, stable water isotopic composition, and major and trace ion concentrations was large and for almost all parameters larger than the temporal variability. Concentrations of copper, zinc, and lead were highest at sites that were relatively dry, whereas concentrations of manganese and iron were highest at sites that had persistent shallow groundwater levels. The major cation and anion concentrations were only weakly correlated to individual topographic or hydrodynamic characteristics. However, we could distinguish four shallow groundwater types based on differences from the catchment average concentrations: riparian zone‐like groundwater, hillslopes and areas with small upslope contributing areas, deeper groundwater, and sites characterized by high magnesium and sulfate concentrations that likely reflect different bedrock material. Baseflow was not an equal mixture of the different groundwater types. For the majority of the campaigns, baseflow chemistry most strongly resembled riparian‐like groundwater for all but one subcatchment. However, the similarity to the hillslope‐type groundwater was larger shortly after snowmelt, reflecting differences in hydrologic connectivity. We expect that similar groundwater types can be found in other catchments with steep hillslopes and wet areas with shallow groundwater levels and recommend sampling of groundwater from all landscape elements to understand groundwater chemistry and groundwater contributions to streamflow.  相似文献   

Spatial variability in specific discharge and streamwater chemistry during low flows: Results from snapshot sampling campaigns in eleven Swiss catchments     

Marius G. Floriancic  Benjamin M. C. Fischer  Peter Molnar  James W. Kirchner  Ilja H.J. van Meerveld 《水文研究》2019,33(22):2847-2866

Catchments consist of distinct landforms that affect the storage and release of subsurface water. Certain landforms may be the main contributors to streamflow during extended dry periods, and these may vary for different catchments in a given region. We present a unique dataset from snapshot field campaigns during low‐flow conditions in 11 catchments across Switzerland to illustrate this. The catchments differed in size (10 to 110 km²), varied from predominantly agricultural lowlands to Alpine areas, and covered a range of physical characteristics. During each snapshot campaign, we jointly measured streamflow and collected water samples for the analysis of major ions and stable water isotopes. For every sampling location (basin), we determined several landscape characteristics from national geo‐datasets, including drainage area, elevation, slope, flowpath length, dominant land use, and geological and geomorphological characteristics, such as the lithology and fraction of quaternary deposits. The results demonstrate very large spatial variability in specific low‐flow discharge and water chemistry: Neighboring sampling locations could differ significantly in their specific discharge, isotopic composition, and ion concentrations, indicating that different sources contribute to streamflow during extended dry periods. However, none of the landscape characteristics that we analysed could explain the spatial variability in specific discharge or streamwater chemistry in multiple catchments. This suggests that local features determine the spatial differences in discharge and water chemistry during low‐flow conditions and that this variability cannot be assessed a priori from available geodata and statistical relations to landscape characteristics. The results furthermore suggest that measurements at the catchment outlet during low‐flow conditions do not reflect the heterogeneity of the different source areas in the catchment that contribute to streamflow.  相似文献   

黑方台台塬斜坡变形破坏的结构面效应研究   总被引：2，自引：0，他引：2       下载免费PDF全文

刘亚峰  刘高  陈小军  黄迪  赵栋 《地震工程学报》2019,41(4):908-915

结构面对于黑方台台塬斜坡变形破坏的影响研究成果较多,但以单方面研究为主,较少进行系统研究,因此通过对黑方台台塬结构面类型及其组合特征以及斜坡变形破坏类型和特征的分析可知:研究区结构面类型主要包括节理裂隙、层面、接触面、断层和临空面,结构面组合类型分2大类8小类,各类型具有自身的结构特征和分布特征;结构面及其组合对黑方台台塬斜坡变形破坏类型选择和空间分布选择控制效应明显,特别是对滑坡类型选择和空间分布的影响。  相似文献   

晋冀蒙交界地区中小地震视应力时空分布特征     

张丽晓  张磊  闫俊岗  申炫烨 《地震地磁观测与研究》2019,40(4):28-36

选取晋冀蒙交界地区固定和临时测震台网记录的2014-2016年地震波形资料，采用近震Brune模型，结合遗传算法，反演计算298次M_L ≥ 2.0中小地震视应力值，分析震源参数之间的标度关系，并按照震中分区，分析不同地区视应力时序变化特征及不同震级区间视应力空间分布特征，发现该区多处存在视应力高值现象，地震多发生于视应力高值异常及附近地区，与断裂带有一定对应关系。  相似文献