The influence of rainfall and land use patterns on soil erosion in multi-scale watersheds: A case study in the hilly and gully area on the Loess Plateau,China

Soil erosion has become a major global environmental problem and is particularly acute on the Loess Plateau (LP), China. It is therefore highly important to control this process in order to improve ecosystems, protect ecological security, and maintain the harmonious relationship between humans and nature. We compared the effects of rainfall and land use (LU) patterns on soil erosion in different LP watersheds in this study in order to augment and improve soil erosion models. As most research on this theme has so far been focused on individual study areas, limited analyses of rainfall and LU patterns on soil erosion within different- scale watersheds has so far been performed, a discrepancy which might influence the simulation accuracies of soil erosion models. We therefore developed rainfall and LU pattern indices in this study using the soil erosion evaluation index as a reference and applied them to predict the extent of this process in different-scale watersheds, an approach which is likely to play a crucial role in enabling the comprehensive management of this phenomenon as well as the optimized design of LU patterns. The areas considered in this study included the Qingjian, Fenchuan, Yanhe, and Dali river watersheds. Results showed that the rainfall erosivity factor (R) tended to increase in these areas from 2006 to 2012, while the vegetation cover and management factor (C) tended to decrease. Results showed that as watershed area increased, the effect of rainfall pattern on soil erosion gradually decreased while patterns in LU trended in the opposite direction, as the relative proportion of woodland decreased and the different forms of steep slope vegetation cover became more homogenous. As watershed area increased, loose soil and craggy terrain properties led to additional gravitational erosion and enhanced the effects of both soil and topography.     

The environmental quality of the sewage discharge area of Qingdao Cove—A cladistic analysis

This study on the environmental quality of the Qingdao Cove intertidal zone sewage discharge area is based on data obtained from the December of 1989 and 1990 macrobenthos investigations there, and uses pollution indicator species and computer aided cladistic analysis to divide the area into a polluted area and a semipolluted area. The study showed the environmental quality in 1990 improved over that in 1989. Project supported by the National Natural Science Fonndation of China     

1208-1369年陕甘宁交界地区干湿变化

More than 240 items of historical records containing climatic information were retrieved from official historical books, local chronicles, annals and regional meteorological disaster yearbooks. By using moisture index and flood/drought (F/D) index obtained from the above information, the historical climate change, namely wet-dry conditions in borderland of Shaanxi Province, Gansu Province and Ningxia Hui Autonomous Region (BSGN, mainly included Ningxialu, Hezhoulu, Gongchanglu, Fengyuanlu and Yan’anlu in the Yuan Dynasty) was studied. The results showed that the climate of the region was generally dry and the ratio between drought and flood disasters was 85/38 during the period of 1208–1369. According to the frequencies of drought-flood disasters, the whole period could be divided into three phases. (1) 1208–1240: drought dominated the phase with occasional flood disasters. (2) 1240–1320: long-time drought disasters and extreme drought events happened frequently. (3) 1320–1369: drought disasters were less severe when flood and drought disasters happened alternately. Besides, the reconstructed wet-dry change curve revealed obvious transition and periodicity in the Mongol-Yuan Period. The transitions occurred in 1230 and 1325. The wet-dry change revealed 10- and 23-year quasi-periods which were consistent with solar cycles, indicating that solar activity had affected the wet-dry conditions of the study region in the Mongol-Yuan Period. The reconstructed results were consistent with two other study results reconstructed from natural evidences, and were similar to another study results from historical documents. All the above results showed that the climate in BSGN was characterized by long-time dry condition with frequent severe drought disasters during 1258 to 1308. Thus, these aspects of climatic changes might have profound impacts on local vegetation and socio-economic system.     

中国大陆地壳运动与强震关系研究

利用GPS观测结果研究了中国大陆当前地壳运动的空间分布及其所揭示的大区域构造变形背景与趋势;讨论了区域水平运动、应变率场分布与强震地点的关系;通过对昆仑山口西Ms8.1等地震区域水平运动与形变的分析,研究了强震过程的区域形变场变化的主要特征;提出了识别孕震形变场以进行中长期强震地点预测的思路和途径。     

内蒙古贫困地区生态安全评价及空间格局分析

在压力-状态-响应(Pressure-State-Response, PSR)模型确立指标体系的基础上,采用灰色关联度分析和熵值赋权相结合的方法,测算出2012年内蒙古贫困地区生态安全综合,压力,状态和响应指数,对研究区生态安全状况进行综合评价;并利用地理空间分析方法和空间分析软件GeoDA对生态安全综合状况进行空间相关性分析,同时结合研究区自然地理特征和社会经济状况,对其生态安全空间格局特征及成因进行诊断性分析.研究发现:(1) 内蒙古贫困地区生态安全水平整体处于一般状态,等级布局具有大聚集,小分散的特点;(2) 生态安全状况分布并非完全随机性,而是表现出空间相似值之间的空间聚集,具有正相关性;(3) 生态安全等级分布状况呈现出区域分异的特点,总体表现为内蒙古西部和东部贫困地区处于一般状态,而中部贫困地区生态安全水平整体处于良好状态,区域内部生态安全水平具有明显的县域差异;(4) 生态安全水平较好的县域和生态安全处于一般水平的县域,压力,状态,响应指标方面差距明显,且影响因素各异.     

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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。     

A back-propagation neural-network-based displacement back analysis for the identification of the geomechanical parameters of the Yonglang landslide in China

Xigeda formation is a type of hundred-meter-thick lacustrine sediments of being prone to triggering landslides along the trunk channel and tributaries of the upper Yangtze River in China. The Yonglang landslide located near Yonglang Town of Dechang County in Sichuan Province of China, which was a typical Xigeda formation landslide, was stabilized by anti-slide piles. Loading tests on a loading-test pile were conducted to measure the displacements and moments. The uncertainty of the tested geomechanical parameters of the Yonglang landslide over certain ranges would be problematic during the evaluation of the landslide. Thus, uniform design was introduced in the experimental design, and by which, numerical analyses of the loading-test pile were performed using Fast Lagrangian Analysis of Continua (FLAC^3D) to acquire a database of the geomechanical parameters of the Yonglang landslide and the corresponding displacements of the loading-test pile. A three-layer back-propagation neural network was established and trained with the database, and then tested and verified for its accuracy and reliability in numerical simulations. Displacement back analysis was conducted by substituting the displacements of the loading-test pile to the well-trained three-layer back-propagation neural network so as to identify the geomechanical parameters of the Yonglang landslide. The neural-network-based displacement back analysis method with the proposed methodology is verified to be accurate and reliable for the identification of the uncertain geomechanical parameters of landslides.     

淮河流域水文随机方法的径流图化(英文)

Theoretical difficulties for mapping and for estimating river regime characteristics in a large-scale basin remain because of the nature of the variable under study: river flows are related to a specific area, i.e. the drainage basin, and are hierarchically organized in space through the river network with upstream-downstream dependencies. Another limitation is there are not enough gauge stations in developing countries. This presentation aims at de-veloping the hydro-stochastic approach for producing choropleth maps of average annual runoff and computing mean discharge along the main river network for a large-scale basin. The approach applied to mean annual runoff is based on geostatistical interpolation proce-dures coupled with water balance and data uncertainty analyses. It is proved by an applica-tion in the upstream at Bengbu in the Huaihe River Basin, a typical large-scale basin in China. Hydro-stochasitic approach in a first step interpolates to a regular grid net and in a second step the grid values are integrated along rivers. The interpolation scheme includes a con-straint to be able to account for the lateral water balance along the rivers. Grid runoff map with 10 km × 10 km resolution and the discharge map along the river with the 1 km basic length unit are the main results in this study. This kind of statistic approach can be widely used be-cause it avoids the complexity of hydrological models and does not depend on the meteoro-logical data.     

中国工业烟粉尘排放时空演化及其影响因素

采用空间分析和空间杜宾模型等方法,研究1999—2017年中国工业烟粉尘排放时空演化特征及其影响因素。结果表明:①中国工业烟粉尘排放空间分布差异明显,其排放的基尼系数和污染物分布指数均呈现下降态势,空间集中程度有所缓和。②中国工业烟粉尘排放空间分布呈东北-西南走向,其排放中心不断由东南向西北方向迁移。③中国工业烟粉尘排放存在空间相关性和空间溢出效应,其冷热点区空间分布发生显著变化。④能源消耗、第二产业比重、人口密度和经济发展水平的提升将会增加工业烟粉尘排放,而外资水平、治理技术水平和环境规制力度的提升则有利于减少工业烟粉尘排放。