近10 a来民勤盆地地下水埋深的空间异质性分析   总被引：1，自引：1，他引：0       下载免费PDF全文

马金辉  韩金华  张艳林 《干旱区地理》2013,36(1):1-7

 在GIS环境下,采用地统计空间分析技术,利用民勤盆地1999-2008年10?a的地下水位观测资料,在插值获取逐年地下水埋深栅格数据的基础上,对民勤盆地地下水埋深的时空格局和空间异质性进行了分析。结果表明：（1）1999-2008年民勤盆地地下水埋深急剧增大,整体平均每年增加幅度为0.52?m,地下水降落漏斗区逐年扩大,并有与附近漏斗区融合的趋势;（2）1999-2008年10 a间的地下水埋深的空间相关性逐年增大,表明民勤盆地地下水埋深的空间结构性逐年增强,地下水储存的空间连通性增加,地下水位的可恢复性和持续可开采性更为脆弱,影响地下水埋深的随机性因素逐渐下降,而人类活动对地下水埋深的影响越来越强烈。  相似文献   

城乡差距的核心-边缘模型分析     

曾伟军 《地域研究与开发》2013,32(3)

将地区划分为城区和农村两区域系统,构建一个综合考虑城乡劳动力迁移、环境污染、农业生产效率、城乡贸易和公共服务基础设施建设等诸因素的核心-边缘模型,以深入系统地考察城乡差距问题,对于解决现有城乡问题有着重要的理论和现实意义.研究表明:劳动力向城区迁移有助于提高城镇和农村居民的生活效用水平,并缩小城乡差距;环境污染物排放对居民生活造成负面影响,生产活动的集聚对城乡差距的影响取决于污染的危害程度;倘若农业生产的环境影响较小,农业生产效率的提高可以缩小城乡差距;城乡间交通基础设施建设、城区交通及通信设施建设和产业集聚等将提高城镇居民效用水平,拉大城乡差距.  相似文献   

西北河谷盆地生态系统服务的权衡与协同分析——以银川盆地为例   总被引：1，自引：0，他引：1  

李鸿健  任志远  刘焱序  张静 《中国沙漠》2016,36(6):1731-1738

明晰生态系统服务权衡与协同的表现类型、形成机理、尺度依存和区域差异,是制定区域发展与生态保护“双赢”政策措施的有效途径。以银川盆地为研究区,对2000年和2014年净初级生产力（NPP）、保土、保水、固沙等生态系统服务物质量进行估算,利用相关分析法、ESTD模型和空间热点制图法分析了生态系统服务之间的权衡协同关系和生态环境空间分布特征及形成机理。结果表明：2000-2014年,4种生态系统服务物质量都有显著提高;空间分布均呈现中间高,四周低的格局;相关分析显示协同作用是各生态系统服务之间的主导关系;NPP与保水、固沙之间的协同程度较高;空间热点制图显示高值项增加的栅格占总数21.64%,高值项减少的栅格占总数21.49%;表明在银川盆地整体生态系统服务功能增加的趋势下内部增减规律并不一致。在南北方向上降水因素对生态系统服务有主导性影响,相关度为0.368;在东西方向上起主导作用的是植被和海拔,相关度分别为0.572和0.563;在东北-西南方向上海拔和湿度对生态系统的影响最大,相关度分别为-0.487和-0.417;在西北-东南方向上其主要影响的也是海拔和湿度,相关度为0.628和-0.628。生态系统服务的权衡与协同关系随尺度的变化而变化,具有明显的尺度依存性;同一尺度空间分布格局的影响因素也存在很大的差异性。  相似文献   

宁夏盐池沙地3种植物群落土壤表层养分的空间异质性   总被引：1，自引：0，他引：1  

刘丽丹  谢应忠  邱开阳  时项峰 《中国沙漠》2013,33(3):782-787

采用经典统计学和地统计学方法,通过半变异函数及其模型、克里格局部插值估计、空间分布图及分形维数等对宁夏盐池沙地3种植物群落(牛枝子、牛枝子-黑沙蒿、黑沙蒿)土壤表层养分的空间异质性进行了研究。结果表明:0~5 cm土壤有机质、全氮、速效磷含量的空间自相关尺度分别是67 m、519 m、143 m;结构方差比分别为0.558、0.882、0.514,说明结构性因素和随机性因素在0~5 cm土壤有机质和速效磷的空间分布中共同发挥作用。全氮表现出较强空间自相关性,在空间分布上具有明显的结构特征,表明结构性因素在其空间总变异中发挥主导作用。空间格局图反映出0~5 cm土壤有机质、全氮含量表现为牛枝子群落较高,经牛枝子-黑沙蒿群落,含量逐渐减少,至黑沙蒿群落含量又有所增加;0~5 cm土壤速效磷含量表现为牛枝子群落和黑沙蒿群落含量较高而牛枝子-黑沙蒿群落含量较低的趋势。反映出研究区从牛枝子群落经牛枝子-黑沙蒿群落至黑沙蒿群落,植被从以草原种为主的群落,逐渐灌木化,植物群落结构组成由复杂到简单的过程,深刻影响了土壤养分的分布格局,导致了土壤“肥力岛”的形成和发展,又反作用引起研究区植物群落的进一步灌丛化,并逐步向沙漠化的方向发展的趋势。  相似文献   

Changes in zooplankton community structure in Sanmen Bay, China     

LIU Zhensheng  ZHANG Zhinan  WANG Chunsheng  JIN Haiyan  DU Mingmin  ZHANG Dongsheng 《海洋学报(英文版)》2012,31(6):104-116

Seasonal variations in zooplankton abundance,biomass,species diversity and community structure were investigated in the Sanmen Bay,China.Samples were collected from 15 stations,on the seasonal basis,in April(spring),July(summer) and October 2005(autumn) and January 2006(winter),respectively.The results show that zooplankton species number,abundance and biomass varied widely and had distinct spatial heterogeneity in the Sanmen Bay.A total of 72 species of zooplankton belonging to 56 genera and 17 groups of pelagic larvae were identified.The zooplankton species richness was strongly related to salinity.Based on hierarchical cluster analysis,zooplankton in this study area were classified into three groups:coastal,neritic and pelagic groups,which corresponded to the upper,middle and lower portion of the Sanmen Bay,respectively.The coastal low-saline species were dominant in the study area.The zooplankton abundance and biomass reached a peak in summer,moderate in spring and autumn,and the lowest in winter.Zooplankton abundance decreased from the upper to lower portion of the bay in April,when the highest biomass occurred in the middle portion of the bay.There were the same spatial distribution patterns for the biomass and abundance in July,with the maximum in the middle of the bay.However,zooplankton abundance was the highest in the middle of the bay in October,when maximum biomass occurred near the lower of the bay.Zooplankton abundance and biomass were evenly distributed in the Sanmen Bay in January.Spatial and temporal variations in zooplankton and their relationship with environmental factors were also analyzed.The BIOENV results indicate that the combination of chlorophyll a(Chl-a),salinity,dissolved inorganic nitrogen(DIN),dissolved oxygen(DO) and silicate(SiO3) was responsible for the variations in zooplankton community structure in the Sanmen Bay.The environmental changes played an important role in changes in the zooplankton community structure in the Sanmen Bay.  相似文献   

石羊河下游民勤绿洲地下水矿化度的时空变异   总被引：38，自引：1，他引：37  

李小玉  宋冬梅  肖笃宁 《地理学报》2005,60(2):319-327

结合地理信息系统,运用地统计学方法研究石羊河下游民勤绿洲近15年来的地下水矿化度的时空变异规律及其与土地利用变化的关系。结果表明:(1)在1987年和2001年的两个时期地下水矿化度的实验变异函数值与理论变异函数拟合较好,F检验达到极显著水平;(2)地下水矿化度在4km以下小尺度上的随机变异SHR特别小,而在4～40km的中尺度上的结构性变异SHA达99.9%,可以认为研究区域内地下水矿化度在整个尺度上具有恒定的变异;(3)Kriging插值及其与同期的绿洲景观类型图进行叠加运算表明,在变化趋势上,除坝区东南部略有下降外,整个绿洲地下水矿化度都增大,北部湖区最显著;在变化面积上,地下水矿化度在3.0g/L以下的面积从1987年的75.26%降到了2001年的58.54%;而其>4.5g/L的绿洲主要集中在湖区。地下水矿化度较低区域的耕地面积减少,而地下水矿化度3.0g/L以上的耕地面积从7.03%增加到了14.32%,特别是湖区,地下水的矿化已严重威胁到了耕地的存在。  相似文献   

1990-2005年广州城市土地覆被景观变化   总被引：5，自引：1，他引：4  

龚建周  刘彦随  夏北成 《地理学报(英文版)》2009,19(2):213-224

Urbanization has been the most important process that changed land cover landscape in Guangzhou since reformation, especially since 1990. It is essential for monitoring and assessing ecological consequences of urbanization to understand landscape quantitative characteristics and its changes. Based on four land-cover type maps interpreted from remote sensing TM images of 1990, 1995, 2000 and 2005, combining gradient analysis with landscape metrics, the quantified spatial pattern and its dynamics of urbanization in Guangzhou was got. Three landscape metrics were computed within different regional areas including the whole study area, two transects along two highways (one N-S and the other W-E) and radiation zones with equal distance outwards the city center were set. Buffer zones for transects N-S and W-E were outlined along highways. The following questions should be answered in this paper: What responses were implied with changing spatial grain size or extent for landscape pattern analysis? Could gradient progress of urbanization be characterized by landscape pattern analysis? Did landscape metrics reveal urban expanding gradually? Were there directional differences in land cover landscape pattern during urbanizing development? The results gave some affirmative answers. Landscape pattern exhibited obviously scale-dependent to grain size and extent. The landscape metrics with gradient analysis could quantitatively approach spatial pattern of urbanization. A precise location for urbanized area, like city center and sub-center, could be identified by multiple landscape metrics. Multiple adjunctive centers occurred as indicated by analysis of radiation zones around the city center. Directional differences of landscape pattern along the two transects (N-S and W-E) came into being. For example, fragmentation of landscape in the transect W-E was obviously higher than that in the transect N-S. All in all, some interesting and important ecological implications were revealed under landscape patterns of two transects or radiation zones, and that was the important step to link pattern with processes in urban ecological studies and the basis to improve urban environment.  相似文献   

A case study of spatial heterogeneity of soil moisture in the Loess Plateau, western China： A geostatistical approach   总被引：9，自引：2，他引：7  

BI Huaxing    LI Xiaoyin  LIU Xin  GUO Mengxia    LI Jun Prof.  College of Soil  Water Conservation  Beijing Forestry University  Beijing  China  Key Laboratory of Soil  Water Conservation  Desertification Combating  Ministry of Education  China Researcher  Ji-xian National Ecological Station of China  China Graduate student 《国际泥沙研究》2009,24(1):63-73

Soil moisture distribution shows highly variation both spatially and temporally. This study assesses the spatial heterogeneity of soil moisture on a hill-slope scale in the Loess Plateau in West China by using a geostatistical approach. Soil moisture was measured by time-domain reflectometry （TDR） in 313 samples. Two kinds of sampling scales were used （2 × 2 m and 20 ×20 m） at two soil layers （0-30 cm and 30-60 cm）. The general characteristics of soil moisture were analyzed by a classical statistics method, and the spatial heterogeneity of soil moisture was analyzed using a geostatistical approach. The results showed that the spherical model is the best-fit model to simulate soil moisture on the experimental hill-slope. The parameters of this model indicated that the spatial dependence of soil moisture in the selected hill-slope was moderate. Even the 2 × 2 m sampling scale was too coarse to show the detailed spatial variances of soil moisture in this area. The dependent distance increased from 27.4 m to 494.16 m as the sampling scale became coarse （from 2× 2 m to 20 ×20 m）. A map of soil moisture was generated by using original soil moisture data and interpolated values determined by the Kriging method. The average soil moisture （area weighted） in the different layers of soil was calculated on the basis of this map （10.94% for the 0-30 cm soil layer, 11.88% for the 30-60 cm soil layer）. This average soil moisture is lower than the corresponding average effective soil moisture, which suggests that the soil moisture is not sufficient to support vegetation in this area.  相似文献   

天山-阿尔泰山拟南芥种群分布与环境的关系     

陶冶  刘彤 《地理科学进展》2009,28(3)

中国的天山及其附近山脉是世界拟南芥及其近缘种的主要分布区之一。在对天山—阿尔泰山的浅山地带拟南芥生存分布多年调查的基础上,选取13个代表性样地及18个相关环境因子,研究了拟南芥种群生存分布与环境因子的关系。结果表明:双向指示种分析(TWINSPAN)将13个拟南芥样地分为4个群落类型:新疆绢蒿、新疆绢蒿—猪毛菜、新疆绢蒿—刺叶锦鸡儿—草原苔草、勿忘草—密穗雀麦—草原苔草4类,各类型对应的环境因子异质性明显。不同群落类型在去势对应分析(DCA)、主成分分析(PCA)和典范对应分析(CCA)各排序图中区分明显,与物种对应较好,与TWINSPAN分类结果基本一致。环境因子的PCA分析发现,坡向、有机质、电导率、pH、土壤含水量和有效钾(均为2个土层)是导致样地间环境异质的主要因素,且这些因子间多呈显著关联。CCA分析发现坡向、有机质、pH、电导率和土壤含水量(均为2个土层)与排序轴相关性最大,分析认为上述环境因子是决定物种分布及多样性格局的主导因子,与环境因子的PCA分析结果基本一致。研究还发现,坡向、土壤含水量(第2层)、有机质(第1层)和pH(两层)是影响各样地十字花科种数变化的主要因素,电导率(第1层)是影响...  相似文献   

基于涡动相关仪验证的SEBS模型对黑河中游地表蒸散发的估算研究     

吴雪娇  周剑  李妍  潘晓多  周彦召 《冰川冻土》2014,36(6):1538-1547

在我国西北干旱和半干旱地区, 农业收获主要依靠灌溉保证, 灌溉绿洲的蒸散发(ET)是当地水资源的主要消耗. 通过遥感估算区域灌溉绿洲的ET对于地区合理利用水资源极其重要, 利用MODIS/Terra 影像, 基于物理过程的地表能量平衡模型(SEBS), 结合WRF模式输出的气候驱动数据和地面观测数据来估算黑河中游地区的地表通量和日蒸散发(ET_daily). 估算的ET用不同下垫面的涡动相关仪观测数据进行验证, 结果显示: SEBS模型估算的不同下垫面的ET_daily具有很好的拟合效果(R²=0.96, P<0.001), 在灌溉绿洲估算的ET_daily比实测值偏高, 说明干旱、半干旱地区灌溉绿洲土壤水分胁迫是影响ET的主要因素. 模型估算绿洲作物生长期间的ET_daily和实测的ET_daily平均相对误差为12.5%, 精度在观测的能量不闭合误差以内且精度比戈壁和沙漠地区高.  相似文献