1985-2005年环渤海地区土地利用变化时空格局

Based on TM image data and other survey materials, this paper analyzed the spatiotemporal patterns of land use change in the Bohai Rim during 1985–2005. The findings of this study are summarized as follows: (1) Land use pattern changed dramatically during 1985–2005. Industrial and residential land in urban and rural areas increased by 643,946 hm², of which urban construction land had the largest and fastest increase of 294,953 hm² at an annual rate of 3.72%. (2) The outward migration of rural population did not prevent the expansion of residential land in rural areas by 184,869 hm². This increase reveals that construction of rural residences makes seriously wasteful and inefficient use of land. (3) Arable land, woodland and grassland decreased at a rate of −0.02%, −0.12% and −1.32% annually, while unused land shrank by 157,444 hm² at an annual rate of −1.69%. (4) The change of land use types showed marked fluctuations over the two stages (1985–1995 and 1995–2005). In particular, arable land, woodland and unused land experienced an inversed trend of change. (5) There was a significant interaction between arable land and woodland. Industrial construction land in urban and rural areas showed a net trend of increase during the earlier period, but only adjustment to its internal structure during the second period. The loss of arable land to the construction of factories, mines and residences took place mainly in the fringe areas of large and medium-sized cities, along the routes of major roads, as well as in the economically developed coastal areas in the east. Such changes are closely related to the spatial differentiation of the level of urbanization and industrialization in the region.     

西安城市化与水资源利用关系的量化研究

基于1997-2010年的统计数据,利用统计分析软件SPSS17.0的主成分分析导出西安城市化水平综合得分,进而运用所建立的回归模型分析了西安城市化与城市用水量、用水效益、人均用水水平之间的定量关系.结果表明:西安城市化发展中,生产用水量随城市化的推进呈三次函数曲线型降低,生活用水量则相反;用水效益与城市化呈线性增长关系;人均生产用水量随城市化水平的提高呈三次函数曲线型降低,人均生活用水量则相反.据此,提出未来西安在城市化推进过程中应重视优化产业结构,发展节水技术,改善用水结构,提高用水效益,实现城市化与水资源、水环境的协调发展.     

京津冀及周边一般性降水与短时强降水特征对比

京津冀及周边地区为我国北方强降水的多发区域。基于1966—2021年87个国家级气象站逐小时降水资料对比分析暖季5—9月一般性降水和短时强降水的空间分布及年际变化,并基于1980—2021年298个气象站分析日变化等特征。结果表明：京津冀及周边地区的渤海西侧平原区域存在短时强降水强度极端性显著区域。渤海西侧平原以外区域两类降水平均小时降水量、强度和降水时次百分比均呈增长趋势,但短时强降水的增幅更高,而渤海西侧平原区域趋势则均不明显。渤海西侧平原区域和渤海西侧平原以外区域的一般性降水平均小时降水量和降水时次百分比日变化幅度显著弱于短时强降水;7—9月渤海西侧平原区域降水夜发性更明显,且相比另一区域半峰持续时间多出约2 h。2005年后渤海西侧平原区域和渤海西侧平原以外区域短时强降水平均小时降水量和降水时次百分比下午时段均明显减弱,但午夜后至清晨明显增加。     

GPS automatic monitoring system for outside deformation of Geheyan Dam on the Qingjiang River

In this paper, the background of developing GPS Automatic Monitoring System for outside deformation of Geheyan Dam is described concisely. The framework, precision and features of the system are stated in detail. Finally, the prospective application of the system is introduced.     

中国公路运输全要素生产率时空演化及区域竞争——基于Hicks-Moorsteen指数框架

运用Hicks-Moorsteen TFP指数法对中国公路运输业全要素生产率进行测度和演化分析。结果发现：2009~2012年中国公路全要素生产率实现了增长,2013~2015年出现下降。2009年来技术进步推动了东部地区公路运输全要素生产率的增长,而运营效率提升则在推动中西部地区公路运输全要素生产率增长时起到了关键作用。中西部地区公路运输效率增长优于东部地区。东部地区在引领技术进步的同时,应注重公路运输效率的提升;中西部地区应注意加大先进技术的引进。政府和主管部门对中西部公路运输应推出持续性支持政策。     

钱家营矿首采区断层在剖面上的延伸规律

通 过对 开滦钱 家营 矿首采 区地 质资料 的综 合分析 ,得 出了 该 矿首 采区 断 层在 剖面 上 的变 化特 征 及规 律,并运用这些 规律 ,对未 采区进 行预 测、预报 ,正确 指导了 采掘 工程的 顺利 进行。     

春运人口流动透视的转型期中国城市网络结构

基于春运人口流动大数据,选取对外联系度、优势流、城市位序-规模分析等方法对转型期中国城市网络特征进行分析。结果显示：① 城市网络层级结构中蕴藏着位序-规模规律,但与理想的帕累托分布有所区别,城市规模彼此差异相对较小;② 空间距离与城市等级在城市网络联系中发挥支配性作用,保证了城市网络的层级性与有序性;③ 中国城市网络核心联系呈现“两横三纵”特征,该特征与铁路大动脉的空间分布高度吻合;④ 东部地区城市网络联系更加密切,而西北、西南地区则相对稀疏,基本上以“胡焕庸线”为界,而“兰新线”是突破这一限制的潜在力量;⑤ 中国东北地区未形成明显的区域性中心,城市联系形成带状网络;⑥ 华北与华南地区的“灯下黑”现象值得警惕,缓解这一问题的可行办法是核心城市功能的对外疏散,加强核心城市与周边城市之间的联系;⑦ 带状区域发展或许将成为未来中国区域经济发展的流行模式和中坚力量。总体上看,针对于揭示转型期中国城市网络结构特征,春运人口流动数据具有一定的研究价值,是城市与人口研究领域一个值得深入挖掘的重要数据源。     

内蒙古大克泊碱湖氮移除及其影响因素

为了研究碱湖N₂O释放速率及其对盐度与pH的响应,选取内蒙古大克泊碱湖的五个沉积物样点,采用¹⁵N同位素标记模拟实验,研究反硝化和厌氧氨氧化的速率、相对比例和气体产生情况,揭示高盐和高pH对碱湖氮移除的影响。发现大克泊湖潜在氮移除速率为0~16.06 n mol N mL-1 h-1,潜在反硝化速率为0~12.62 n mol N mL-1 h-1,潜在厌氧氨氧化速率为0~9.81 n mol N mL-1 h-1;当盐度34.00 g·L-1与pH 10.22时,厌氧氨氧化对氮移除贡献较大,达到43.18%~71.79%。反硝化过程气体产物以N₂为主,几乎无N₂O气体释出。另外,该区域潜在氮移除速率与pH呈正相关关系,与TOC、NO-₃、HCO-₃呈负相关关系;未发现氮移除速率与盐度之间的相关关系。因此,在研究的碱湖中,氮移除过程中主要为N₂排放,而N₂O低于检测水平;氮移除过程的影响因素复杂且不限于最主要的环境变量(盐度与pH)。这些结果为研究湖泊N₂O排放提供了数据基础。     

Effect of a thermokarst lake on soil physical properties and infiltration processes in the permafrost region of the Qinghai-Tibet Plateau,China

Changes in the hydrological processes in alpine soil constitute one of the several key problems encountered with studying watershed hydrology and ecosystem stability against the background of global warming. A typically developing thermokarst lake was chosen as a subject for a study using model simulation based on observations of soil physical properties, infiltration processes, and soil moisture. The results showed that the selected thermokarst lake imposed certain changes on the soil infiltration processes and, with the degree of impact intensifying, the initial infiltration rate decreased. The greatest reduction was achieved in the area of moderate impact. However, the stable infiltration rate and cumulative infiltration gradually increased in the surface layer at a depth of 10 and 20 cm, both decreasing initially and then increasing, which is correlated significantly with soil textures. Moreover, the cumulative infiltration changed in line with steady infiltration rate. Based on a comparative analysis, the Horton model helps better understand the effect on the soil infiltration processes of the cold alpine meadow close to the chosen thermokarst lake. In conclusion, the formation of the thermokarst lake reduced the water holding capacity of the alpine meadow soil and caused the hydraulic conductivity to increase, resulting in the reduction of runoff capacity in the area of the thermokarst lake.     

Experimental research on physical properties of saline soil subgrade filler in Chaerhan region

In order to improve the engineering stability of saline soil of high chloride content in the Chaerhan salt lake region, six typical characteristics saline soil samples were selected, and tests on their...