岫岩-海城5.4级地震前小震震源机制解与记录特征分析

采用Pn、Pg初始波初动符号，利用乌尔夫网上半球投影，用作图方法求解了岫岩－海城震区（1999年1月－1999年11月29日）主震前辽宁数字地震台网记录（ML≥2.5)的41个小震的震源机制参数。结合前震记录的某些特征，对主震前应力方向的时空变化，震源错动性质进行分析和讨论。     

河流静水滩区潜流带水交换空间分布模式研究（英文）

Hyporheic zone(HZ) influences hydraulic and biogeochemical processes in and alongside streams, therefore, investigating the controlling geographic factors is beneficial for understanding the hydrological processes in HZ. Slack water pool (SWP) is an essential micro-topographic structure that has an impact on surface water and groundwater interactions in the HZ during and after high flows. However, only a few studies investigate HZ surface water and groundwater exchange in the SWP. This study used the thermal method to estimate the HZ water exchange in the SWP in a segment of the Weihe River in China during the winter season. The findings show that on the flow-direction parallel to the stream, river recharge dominates the HZ water exchange, while on the opposing flow-direction bank groundwater discharge dominates the water exchange. The water exchange in the opposing flow-direction bank is about 1.6 times of that in the flow-direction bank. The HZ water exchange is not only controlled by flow velocity but also the location and shape of the SWP. Great water exchange amount corresponds to the shape with more deformation. The maximum water exchange within the SWP is close to the river bank where the edge is relatively high. This study provides some guidelines for water resources management during flooding events.     

Estimating spatial pattern of hyporheic water exchange in slack water pool

Journal of Geographical Sciences - Hyporheic zone (HZ) influences hydraulic and biogeochemical processes in and alongside streams, therefore, investigating the controlling geographic factors is...     

鸭绿江中下游地区生态环境演变分析

对鸭绿江中下游地区近百年来水土流失加剧、野生动植物种群减少、生态功能降低等问题进行分析，指出了人们对该区自然资源掠夺式的开发及其造成的环境污染是导致生态环境恶化的重要因素。对策是重视生态环境综合整治，即生态保护与生态建设同步，环境保护与污染防治同步。     

辽宁区域地震短波通信传播特性和频率选择探讨

辽宁区域地震短波通信网对电磁波在无线通信中的传播特性及频率选择等问题，没有进行深入的理论研究和探讨。笔者将通信工作的实践经验升至理论的高度，研究探讨辽宁区域地震短波通信传播特性和频率选择办法，达到在短波数据通信中，选择最佳频率，增加沟通率的目的     

Impacts of climate change on aridity index and its spatiotemporal variation in the Loess Plateau of China,from 1961 to 2014

The Loess Plateau, the transitional zone between humid and arid regions of China, is an important region to examine the regional hydrological cycle and variation in humid and arid regions under global climate change. Aridity index (AI), the ratio of precipitation (P) to potential evapotranspiration (ET₀), is an important indicator of regional climate conditions and is also used to classify drylands. In this study, data from 51 national meteorological stations during the period of 1961–2014 were collected to estimate the AI in the Loess Plateau. Results show that a downward trend in annual AI was detected and the boundary of the drylands region based on the AI was expanded across the Loess Plateau over the period of 1961–2014. The spatiotemporal variability of P was the main cause in the AI variations. Furthermore, data analysis suggested the occurrences of the extreme minimum AI values were mostly affected by fluctuations of the two factors (ET₀ and P) rather than its corresponding trend during the period. Thus, this study indicated the major driving factor of AI and the relationship between extreme AI values and the global climate anomalies in the Loess Plateau region, and meanwhile, provided an understanding of the impacts of climate change on hydrological cycle in the Loess Plateau of China.     

短波电台对地震仪干扰机理分析及抑制方法

对短波电台发射时干扰地震仪的机理进行了分析。指出干扰形式及干扰噪声进入地震仪的端口，用抗干扰三要素理论结合地震台、站实际条件，采用低通网络抑制干扰，收到了明显的效果     

Depicting urban boundaries from a mobility network of spatial interactions: a case study of Great Britain with geo-located Twitter data

Existing urban boundaries are usually defined by government agencies for administrative, economic, and political purposes. However, it is not clear whether the boundaries truly reflect human interactions with urban space in intra- and interregional activities. Defining urban boundaries that consider socioeconomic relationships and citizen commute patterns is important for many aspects of urban and regional planning. In this paper, we describe a method to delineate urban boundaries based upon human interactions with physical space inferred from social media. Specifically, we depicted the urban boundaries of Great Britain using a mobility network of Twitter user spatial interactions, which was inferred from over 69 million geo-located tweets. We define the non-administrative anthropographic boundaries in a hierarchical fashion based on different physical movement ranges of users derived from the collective mobility patterns of Twitter users in Great Britain. The results of strongly connected urban regions in the form of communities in the network space yield geographically cohesive, nonoverlapping urban areas, which provide a clear delineation of the non-administrative anthropographic urban boundaries of Great Britain. The method was applied to both national (Great Britain) and municipal scales (the London metropolis). While our results corresponded well with the administrative boundaries, many unexpected and interesting boundaries were identified. Importantly, as the depicted urban boundaries exhibited a strong instance of spatial proximity, we employed a gravity model to understand the distance decay effects in shaping the delineated urban boundaries. The model explains how geographical distances found in the mobility patterns affect the interaction intensity among different non-administrative anthropographic urban areas, which provides new insights into human spatial interactions with urban space.     

黄河上中游人工造林对年径流量的影响

流域年径流量是水资源评价与合理配置利用的重要依据,而人工造林的减水作用又是估算水土保持对河川年径流量影响的基础。在综合分析了人工造林减水作用现有主要研究成果,对黄河上中游进行生态环境建设分区的基础上,求算了各分区人工造林减水定额,黄土丘陵沟壑区为93.82 m3/hm2、黄土高塬沟壑区为58.54 m3/hm2、土石山区为168.87 m3/hm2。并结合《2003中国林业统计年鉴》、《2005年中国森林资源报告》,计算了各分区截止2003年人工林地累计面积,黄土丘陵沟壑区、黄土高塬沟壑区、土石山区、河源区分别为119.10×104hm2、45.29×104hm2、34.08×104hm2、2.56×104hm2。最后求得黄土丘陵沟壑区、黄土高塬沟壑区、土石山区、河源区现状人工造林减水量分别为11 173.96×104m3、2 651.28×104m3、5 755.09×104m3、432.31×104m3,全流域现状人工造林减水量为20 012.64×104m3。     

Surface Water-Groundwater Interaction in the Guanzhong Section of the Weihe River Basin,China

As a crucial agricultural and economic development zone since the Qin Dynasty (221 to 206 BC), the Guanzhong section of the Weihe River basin is facing serious water resource shortages due to population growth and regional development. Its water resource amount per capita is only 361 m³, about 1/6 of the average in China and less than 1/20 of the average in the world. Surface water and groundwater (SW-GW) interaction, having a significant influence on the spatiotemporal distribution of water resources, was qualitatively and quantitatively investigated during a wet year based on stable isotopes and hydrochemistry. The results show that the recharge pattern in the north part varies with season, that is, 40% of the surface water recharge comes from groundwater in the dry season, but 93% of the groundwater recharge comes from surface water in the rainy season. In the south part, groundwater is always recharged by surface water, with contributions of 47% and 61% in the rainy and dry seasons, respectively. For the main stream, the recharge pattern is complicated and varies with season and site. This study will provide useful information about SW-GW interaction at basin scale. Integrated management of groundwater and surface water could improve the efficiency of regional water resources utilization and promote accurate and sustainable water management in the semi-arid basin.