1960-2015年青海三江源地区降水时空特征

青海三江源地区是中国生态系统最为敏感和脆弱的地区,其降水特别是生长季降水的波动,是影响本区及江河中下游水资源安全、生态系统可持续发展的关键因素。综合线性趋势、Mann-Kendall检验、BG分割算法、R/S、EEMD等多方法细致辨识了1960-2015年研究区降水量序列的时空特征。结果显示：① 三江源降水量总体呈现弱增趋势,21世纪以来降水量显著增加,各子源区气候倾向率不尽相同;② 年、季降水量自东南向西北递减,澜沧江源区夏季降水和黄河源区秋季降水呈弱减趋势,雨量弱减区在空间上呈斑块状分布;③ 年、季降水量年代际变化和增湿率的空间差异较明显,春夏季降水气候倾向率与经纬度、海拔的复相关性显著高于冬季;④ 20世纪90年代中后期,各子源区降水总体显现增强信号,并于2002年前后发生突变;⑤ 年际和低值年代际显著周期是造成降水量变动的主要因素;⑥ 除澜沧江源区夏季降水趋于减少外,其他年、季降水量变化呈现增幅不一的转湿趋势;⑦ 横向比较各子源区可见,长江源区降水变化更能表征高原气候变化。研究结果显示,研究区降水时空序列变化具有明显的区域和季节差异性特征,与以往类似研究存在些许差异,可见为有效提高气候序列演变过程及突变诊断的准确性,仍需进一步融合多方法实施集成分析。     

用CAPPI和PPI资料测定区域降水量精度比较

应用上海中心气象台７１４数字化天气雷达的体积扫描资料所得的不同高度上的ＣＡＰＰＩ资料和低仰角时ＰＰＩ资料。估算区域降水量并得到降水量分布形势。然后采用平均校准法进行了校准，最后又与用雨量计网测量的区域降水量及其分布形势作了比较，得到一些有意义的结果。     

黄河中游降雨特性对泥沙粒径的影响

以黄河中游36个有泥沙粒径资料的水文测站流域为样本，在不同自然地理类型流域划分的基础上，建立了流域泥沙粒径特片与降雨特性的关系。结果表明，在不同类型流域，流域泥沙的粗细与降雨季节性变率和年际变率之间存在着相当好的线性正相关关系；而与年降雨量和降雨不均匀系数之间呈明显的非线性关系。流域地面物质、植被和地貌发育程序等下垫面环境因素对泥沙粒径特性与降雨特性之间关系起着十分重要的控制作用。不同类型流域曲线的斜率各不相同，在图中所处的位置也不相同。     

吉林地区地电场变化特征分析研究

本文在初步介绍了吉林地区地电场观测台网基本概况的基础上, 对该区域记录到的地电场的基本变化特征进行了统计分析。 研究表明: ① 绝大部分台站记录到了比较典型的地电场静日变化, 主要表现为“峰—谷—峰”形态, 该变化形态在时间上具有同步性; ② 所有台站均记录到了比较明显的地电暴同步变化, 呈近似南北分布的几个台站记录到了微弱磁扰的同步变化; ③ 地电场日变化幅度呈现比较明显的年变化规律, 不同台站的地电场日变化幅度具有一定的差异性; ④ 正常工作状态下, 各个台站之间同测向观测数据具有比较好的相关性。     

囊果碱蓬离子含量及分布特点

为研究真盐生植物矿质营养特征,以北疆荒漠囊果碱蓬群落为对象,通过土壤及植株调查,分析其矿质元素特征。结果显示：（1）囊果碱蓬的生长增加了0~30cm土壤的pH值、水分及盐份含量,并使盐分在土层重新分布。（2）根系相对于土壤,具有优先吸收K⁺、Mg²⁺ 养分离子的特点;叶片相对于根系,具有优先运输Cl^-、Na⁺、SO₄^2- 盐分离子的特点,同一离子在吸收和运输的选择不一致,与其在整株的功能相关。（3）Cl^-、Na⁺、SO₄^2- 积累于叶片,含量远大于K⁺、Mg²⁺、Ca²⁺ ,Cl^- 和Na⁺ 可能相伴向上运输,K⁺、Ca²⁺、Mg²⁺ 在根、茎、叶保持基本不变的比例。（4）囊果碱蓬属于SO₄ -Cl 盐积累植物,而背景土壤为Cl-SO₄ 型盐土。     

基于地理探测器的喀斯特不同地貌形态类型区土壤侵蚀定量归因

土壤侵蚀形成机制与影响因素识别是当前研究的核心与前沿议题,然而从多因素综合作用的角度进行定量归因仍需加强。以喀斯特典型峰丛洼地流域为研究区,基于GIS手段和RUSLE模型模拟土壤侵蚀,综合土地利用、坡度、降雨、高程、岩性、植被覆盖度等影响因子,应用地理探测器方法针对喀斯特不同地貌形态类型区进行土壤侵蚀的定量归因研究。结果表明,各影响因子对土壤侵蚀的解释力及因子间耦合作用程度在不同地貌形态类型区差异显著,其中土地利用和坡度是决定土壤侵蚀空间异质的主导因子,但在山地丘陵区,随着地形起伏度的升高,坡度的控制作用下降,即地理探测器q值表现为中海拔丘陵>小起伏中山>中起伏中山;生态探测器显示土地利用对土壤侵蚀的影响相比于其他因子有显著差异;双因子交互作用有助于增强对土壤侵蚀的解释力,土地利用与坡度的协同作用对土壤侵蚀的解释力达到70%以上;对于土壤侵蚀空间分布的差异性检验,风险探测器显示在小起伏中山、中起伏中山等地貌形态类型中,具有显著差异的影响因子分层组合数占比至少55%。因而,喀斯特地区土壤侵蚀的治理应综合考虑不同地貌形态类型区土壤侵蚀影响机制的空间异质性。     

Decoding the Development Strategy of a Major Retailer: Wal-Mart's Expansion in the United States

This research aims to provide insight regarding Wal-Mart's retail development strategy in its expansion across the continental United States. The study examines store location patterns and relationships between Wal-Mart's store and distribution center locations and markets. The study shows that, although radial expansion is broadly characteristic of the dense store patterns that have been well established for Wal-Mart at the national level, expansion patterns at the regional level are consistent with a selective process based on factors other than store density. These results provide a new perspective on Wal-Mart's expansion, providing insights of value to retail practitioners and local government.     

Change analysis of rice area and production in China during the past three decades

Rice＇s spatial-temporal distributions, which are critical for agricultural, environ- mental and food security research, are affected by natural conditions as well as socio-eco- nomic developments. Based on multi-source data, an effective model named the Spatial Production Allocation Model （SPAM） which integrates arable land distribution, administrative unit statistics of crop data, agricultural irrigation data and crop suitability data, was used to get a series of spatial distributions of rice area and production with 10-km pixels at a national scale -it was applied from the early 1980s onwards and used to analyze the pattern of spatial and temporal changes. The results show that significant changes occurred in rice in China during 1980-2010. Overall, more than 50% of the rice area decreased, while nearly 70% of rice production increased in the change region during 1980-2010. Spatially, most of the increased area and production were in Northeast China, especially, in Jilin and Heilongjiang; most of the decreased area and production were located in Southeast China, especially, in regions of rapidly urbanization in Guangdong, Fujian and Zhejiang. Thus, the centroid of rice area was moved northeast approximately 230 km since 1980, and rice production about 320 km, which means rice production moved northeastward faster than rice area because of the significant rice yield increase in Northeast China. The results also show that rice area change had a decisive impact on rice production change. About 54.5% of the increase in rice pro- duction is due to the expansion of sown area, while around 83.2% of the decrease in rice production is due to contraction of rice area. This implies that rice production increase may be due to area expansion and other non-area factors, but reduced rice production could largely be attributed to rice area decrease.     

青海省气象灾害的若干气候特征分析

利用1984-2007年气象灾害资料, 分析了青海省各类气象灾害的发生机率及时空分布特征.冰雹、 暴雨洪涝、 雪灾、 干旱和雷电及霜冻是青海省主要气象灾害, 连阴雨、 大风、 沙尘暴、 冻害、 渍涝、 高温、 龙卷风、 大雾为青海次要气象灾害.在地域分布上, 海南州和海东地区是青海气象灾害多发和危害严重地区; 玉树州和果洛州属于气象灾害发生较少和危害较轻地区.就行政县域而言, 西宁市湟中县、 海南州兴海县、 贵德县为青海气象灾害多发县, 果洛州班玛县、 久治县、 玉树州治多县则是青海省气象灾害较少和危害较轻县份.年内5-6月出现的气象灾害种类最多, 4-9月份是气象灾害高发期.在1984-2007年间, 暴雨洪涝、 冰雹、 雷电灾害发生次数呈增多趋势, 其他灾害发生次数增多趋势不甚明显.     

基于地理探测器的喀斯特不同地貌形态类型区土壤侵蚀定量归因（英文）

The formation mechanism and influencing factors identification of soil erosion are the core and frontier issues of current research. However, studies on the multi-factor synthesis are still relatively lacked. In this study, the simulation of soil erosion and its quantitative attribution analysis have been conducted in different geomorphological types in a typical karst basin based on the RUSLE model and the geodetector method. The influencing factors, such as land use type, slope, rainfall, elevation, lithology and vegetation cover, have been taken into consideration. Results show that the strength of association between the six influencing factors and soil erosion was notably different in diverse geomorphological types. Land use type and slope were the dominant factors of soil erosion in the Sancha River Basin, especially for land use type whose power of determinant(q value) for soil erosion was much higher than other factors. The q value of slope declined with the increase of relief in mountainous areas, namely it was ranked as follows: middle elevation hill> small relief mountain> middle relief mountain. Multi-factors interactions were proven to significantly strengthen soil erosion, particularly for the combination of land use type with slope, which can explain 70% of soil erosion distribution. It can be found that soil erosion in the same land use type with different slopes(such as dry land with slopes of 5° and above 25°) or in the diverse land use types with the same slope(such as dry land and forest with a slope of 5°), varied much. These indicate that prohibiting steep slope cultivation and Grain for Green Project are reasonable measures to control soil erosion in karst areas. Based on statistics of soil erosion difference between diverse stratifications of each influencing factor, results of risk detector suggest that the amount of stratification combinations with significant difference accounted for 55% at least in small relief mountain and middle relief mountainous areas. Therefore, the spatial heterogeneity of soil erosion and its influencing factors in different geomorphological types should be investigated to control karst soil loss more effectively.