南水北调中线地区旱涝变化的长期特征

利用近５００年我国旱涝等级历史资料及新中国４０多年气象资料，采用天气、气候及统计方法，计算了中线地区干旱指标，分析了华北地区和汉水上游水库库区干旱分布特征、各区区域性干旱遭遇及库区供水区与北方需水区旱涝变化的长期特征，供南水北调决策参考。

南水北调中线地区土地利用变化及生态环境效应

根据河南境内南水北调中线沿线地区的土地利用数据,分析了土地利用变化的空间特征,并在县域尺度上分析了不同时期土地利用的生态环境效应。结果表明,近年来该区域耕地向建设用地的转移面积较多,但土地利用的整体格局并未发生显著变化,而整个区域内土地利用变化强度的空间分布极不均匀。中线工程施工以来,沿线地区生态环境状况总体上有所改善。

南水北调中线渠首地区生态系统建设

南水北调中线渠首地区大力进行生态系统建设。首先标本兼治,采取措施提高渠首水源区的森林覆盖率,解决水土流失问题;其次,发展绿色农业,建立生态示范区;最后,“实施企业行为绿色化”。大大改善了渠首地区的生态环境,保障了渠首水资源的质量。

南水北调中线重大水旱变化及其影响

南水北调牵涉到的问题很多,东、中、西３线各有其不同的特点、作用、优势、难点和存在的问题。４０余年来,虽已经过了大量工作,但有的问题,如重大洪旱变化对调水的影响等,还应进一步加以重视并加强其有关的工作。本文主要对中线地区这方面的有关问题,进行一些简要讨论。一...

基于PSR模型的南水北调中线主干渠沿线区域生态环境评价

结合生态环境状况指数和修正后的"压力-状态-响应"(PSR)模型,从环境质量状况以及生态安全两个角度分析出发,分别考虑自然影响以及自然、经济、社会三者的协同作用,构建了适用于描述南水北调中线主干渠沿线地区生态环境状况的综合评价指标体系。研究结果表明:评价期内环境质量状况评价等级中,只有鲁山县处于"良",安阳市"较差",其他县区均为"一般";生态安全评价方面,只有淅川县处于较安全状态,其他处于预警和中度预警状态,占研究区总面积的97.54%,中度预警占16.28%。总的来看,2014年研究区生态环境质量整体水平一般,综合生态安全形势不容乐观,需要政府部门加大对主干渠沿线输水地段人类活动的监管力度。

Micromorphological Features of Diagnostic Horizons in Several soils in Southwest China: Implication for Soil Taxonomic Classification

The comparative studies on micromorphological features in diagnostic horizons of Stagnic Anthrosols, Ustic Ferrosols and Ustic Vertosols in southwestern China were conducted to underpin the rationale for Chinese Soil Taxonomy. The following findings were explored: (1) Stagnic Anthrosols had the specific micromorphological features, e.g., the humic formation in anthrostagnic epipedon, the platy structures in plow subhorizon, the secondary formation of ferromanganese and the weakly optical-orientation clay domains in hydragric horizon, etc.: (2) The groundmasses of ferric horizon in Ustic Ferrosols appeared in hue of 2.5YR or redder, and had pellicular grain structure; (3) Ustic Vertosols had a crust horizon (Acr), and crack structure dominated in Acr and angular blocky structure in disturbed horizon; (4) Because of the distinct differences in micromorphological features among these three soils, the specific micromorphological features might be employed as diagnostic horizons to differentiate soils while the quantifiable micromorphological features might potentially be selected as diagnostic indices for Chinese soil taxonomic classification.

Formation and syn-rifting process of the Wan'an Basin, South China Sea

Based on seismic and drilling data, we calculated tectonic subsidence amounts and rates of the Wan'an Basin by backstripping. The genetic mechanism and syn-rifting process of the basin were analyzed in combination with the regional geological setting. The results reveal that the basin syn-rifted in the Eocene and early Miocene under the control of the dextral strike-slip Wan'an Fault Zone. The transtensional/ extentional stresses along this fault zone may be attributed to seafloor spreading of the South China Sea (SCS) in multiple episodes. Extensive basal faults and some small initial rifts in the early Paleogene can be related to southeastward extrusion and clockwise rotation of the Indochina Block. During the Oligocene, the nearly N-S directed spreading of the SCS derived the transtensional stresses in a roughly NW-SE orientation. The basin subsided rapidly in the middle and north to form two major subsidence centers. In the early Miocene, the SCS spread again in a nearly NW-SE direction, resulting in rapid subsidence in the southern basin continuous extending until the period ～16.3 Ma.

Impacts of Climatic Change on River Runoff in Northern Xinjiang of China over Last Fifty Years

The characteristics of climatic change and fiver runoff, as well as the response of fiver runoff to climatic change in the northern Xinjiang are analyzed on the basis of the hydrological and meteorological data over the last 50 years by the methods of Mann-Kendall nonparametric test and the nonlinear regression model. The results show that： 1） The temperature and the precipitation increased significantly in the whole northern Xinjiang, but the precipitation displayed no obvious change, or even a decreasing trend in the northern mountainous area of the northern Xinjiang. 2） River runoff varied in different regions in the northern Xinjiang. It significantly increased in the northern slope of the Tianshan Mountains and the north of the northern Xinjiang （p = 0.05）, while slightly ificreased in the west of the northern Xinjiang. 3） North Atlantic Oscillation （NAO） affects fiver runoff by influencing temperature and precipitation. The NAO and precipitation had apparent significant correlations with the fiver runoff, but the temperature did not in the northern Xinjiang. Since the mid-1990s fiver runoff increase was mainly caused by the increasing temperature in the northern slope of the Tianshan Mountains and the north of the northern Xinjiang. Increased precipitation resulted in increased fiver runoff in the west of the northern Xinjiang.

Engineering Geological Assessment for Route Selection of Railway Line in Geologically Active Area:A Case Study in China

The Cheng-Lan railway links Chengdu, a central city in Southwestern China, and Lanzhou, a central city in Northwestern China. The railway passes through the Longmenshan fault zone (Wenchuan earthquake happened there on May 12, 2008), Minjiang fault zone, and Dongkunlun fault zone, which are all active. It runs over the Yangtze River and the Yellow River, and crosses high mountains and deep valleys. There exists, along the railway's alignment, different kinds of strata of hard granite and soft, weak metamorphic rocks such as carbonaceous slate, schist, and phyllite. It is, therefore, a key issue for such an infrastructure construction to assess the engineering geological conditions and risks, so as to mitigate or avoid possible georisks and to offer optional designs. Geological survey and georisk assessment along the railway corridor are carried out. Special attention is given to active faults, earthquakes and seismic zones. Based on these, discussions about geological aspects for route selection of the railway are conducted and countermeasures for georisk control are proposed accordingly. Main conclusions are achieved as follows: (1) Geohazards such as landslides, rockfalls and debries flows dominate both the route selection of the railway and the engineering structures (e.g., tunnels or bridges) adopted; (2) Tunnel has been proved to be an excellent structure for linear engineering in geologically active area; and (3) In the case where avoiding is impractical, necessary protection measures should be taken to engineering slopes in high earthquake intensity areas, especially the area with earthquake of Ms. 8 or greater.

Atmosphere Transmission Performance for 0.4 μm～0.8 μm Ray Radiation in Middle Latitude of China

This paper researched on the atmospheric transmission performance of 0.4 μm～0.8 μm ray radiation based on the characteristic of the middle latitude atmosphere in China.By analysis of the characteristic of the actual atmosphere,the absorption of molecular and the scattering of the steam and ozone,as well as the aerosol scattering(big granule scattering) are play a leading role to the 0.4 μm～0.8 μm ray radiation.Then a better atmospheric transmission formula in horizontal path has been deducted.The result of computer simulation indicates that this equation can best calculate the transmission performance of 0.4 μm～0.8 μm visible radiation in the middle latitude area of China.This computing result was applied to the nuclear explosion parameter detection system based on 0.4 μm～0.8 μm visible radiation.Through nuclear explosion simulator to produce ray radiation,the tested result indicates that this method has the better measuring precision than the traditional method with the software of LOWTRAN.The calculation result of this formula not only can apply directly to each kind of optoelectronics detecting system,but also to the optical wireless communication system based on the 0.4 μm～0.8 μm ray radiation.

Mineralogy of Selected Paddy Soils in Southeastern China

Limited information is available concerning the mineralogy of paddy soils in the southeastern China.Using chemical methods in conjunction with X-ray diffractometry, we studied the mineral composition of three paddy soils: Jinghua (paddy soil on Quaternary red clay), Fuyang (Hapl-percogenic loamy paddy soil), and Shaoxing (gleyic clayey paddy soil). All the soils contained quartz, mica, vermiculite, chlorite and kaolinite, and the distribution of these minerals varied with soil particle size fractions. The clay fraction of the F’uyang and Shaoxing soils also contained smectite. Although X-ray data did not show the presence of smectite in the Jinghua soil, this mineral was identified by the chemical method, suggesting a transitional property of the mineral in the soil. Hydroxy-Al interlayered minerals were also present in the clay fraction.The amount of smectite in the soils was 31.6 (Shaoxing), 16.5 (Fuyang), and 21.4 (Jinghua) g kg-1; for vermiculite it was 33.3 (Shaoxing), 16.5 (Fuyang), and 8.5 (Jinghua) g kg-1. Smectite was only found in the clay fraction. In contrast, amounts of vermiculite in soil particle size fractions were 3.0～11.4 (sand),2.1～6.0 (coarse silt), 4.6～18.9 (medium silt), 0.9～40.0 (fine silt), and 17.0～108 (clay) g kg-1. The amount of noncrystalline aluminosilicates in the soils in g kg-1 decreased in the order: Shaoxing (2.4) > Jinghua (1.9) > Fuyang (1.7). This study has provided useful mineralogical information that is fundamental in future developmellt of management strategies of the soils.

An Evaluation on the Effects of the Policy of the Great Campaign of Western Development of China in the First 10 Years Based on the Kuznets Regional Inverted-U Theory

In order to reduce the regional differentials or narrow the gap in economic development between eastern and western areas and prevent the intensification of contradictions resulting from the regional inequality during the development process, the government of China launched the Great Campaign of Western Development （GCWD） in 2000. In this paper, we will evaluate the effects of the first 10 years＇ GCWD and use the latest Chinese annual data from 1978 to 2010 to investigate the problem of regional differentials in the development process, evaluate the effects of GCWD policy and test whether there is a regional Kuznets inverted-U curve in the regional development of China. The result shows that there are both good and bad news： the good news is that the inverted U-shaped curve of absolute differential between eastern and western areas finally emerges （the previous studies showed that the inverted-U curve did not appear and the differentials between eastern and western areas became worse） and the bad news is that the differential is in the first half of the inverted U-shaped curve in our choice of time span （1978-2010）, that is, it is still in the situation of deterioration, and the turning better point will emerge in 2025. Although the western areas have benefitted from GCWD, the absolute gap has been still widened. To narrow the gap, the western areas should accelerate the industrial development and the government should adjust the policy and make more efforts to support the development of the industry in the western areas, especially cultivate and support the development of the western characteristic and advantageous industry rather than just supporting the construction of infrastructure in the western areas.

Global structure and seasonal variations of the migrating 6-h tide observed by SABER/TIMED

Ten years of SABER/TIMED temperature data are used to analyze the global structure and seasonal variations of the migrating 6-h tide from the stratosphere to the lower thermosphere. The amplitudes of the migrating 6-h tide increase with altitudes. In the stratosphere, the migrating 6-h tide peaks around 35°N/S. The climatologically annual mean of the migrating 6-h tide clearly shows the manifestation of the(4, 6) Hough mode between 70 and 90 km that peaks at the equator and near 35°N/S. Above 90 km, the 6-h tide shows more than one Hough mode with the(4, 6) mode being the dominant one. The migrating 6-h tide is stronger in the southern hemisphere. Annual, semiannual, 4-, and 3-month oscillations are the four dominant seasonal variations of the tidal amplitude. In the stratosphere and stratopause, the spring enhancement of the 6-h tide at middle latitudes is the most conspicuous feature. From the mesosphere to the lower thermosphere, the tidal amplitude at low latitudes is gradually in the scale of that at middle latitudes and exhibits different temporal variations at different altitudes and latitudes. Both ozone heating in the stratosphere and the background atmosphere probably affect the generation and the seasonal variations of the migrating 6-h tide. In addition, the non-linear interaction between different tidal harmonics is another possible mechanism.

Environment-ecosystem dynamic processes of Spartina alterniflora salt-marshes along the eastern China coastlines

Spartina alterniflora is ecologically important in its original habitat; however, it has caused controversy since it was introduction into China(now it has been spreading rapidly on the Jiangsu, Shanghai, Zhejiang and Fujian coasts). The purpose of the present contribution is, on the basis of an analysis and synthesis of existing data sets, to evaluate the environmental-ecological effects of S. alterniflora, and to identify the relevant scientific problems that require further research in the future. Investigations have shown that, by reducing the near-bed shear stress associated with tidal currents, S. alterniflora can enhance the settling flux of suspended sediment and deposition rate on the tidal flats over the region. Further, field survey and analysis indicate that the S. alterniflora salt-marsh has a high primary production and provides a new type of habitat for the native benthic fauna. Some macro-, meio- and micro-fauna that used to live in the native salt-marshes have adapted to the S. alterniflora salt-marsh, forming a new ecosystem. Under the influences of a number of background factors, such as latitude variations and the coastal type, the environmental-ecological changes induced by Spartine have regional differentiations. To the north of Hangzhou Bay, with a high position of the pre-Holocene stratum base, a large width of the tidal flats, and a gentle bed slope, only a small part of the intertidal zone is occupied by the S. alterniflora salt-marsh. Here, the S. alterniflora salt-marshes mainly play a positive role in coastal protection and ecosystem functioning. In contrary, to the South of Hangzhou Bay, The pre-Holocene deposits are situated in relatively deeo waters, and the width of the tidal flats formed within coastal embayments is relatively narrow. As such, the expansion of S. alterniflora has squeezed the living space of other intertidal organisms, thus has a negative ecological effect. Therefore, the regional differentiation of the Spartina effects should be sufficiently considered in coastal development and management. Furthermore, in order to predict the future evolution of the S. alterniflora wetlands over the region, in addition to in situ monitoring and measurements, an ecosystem dynamic model should be established, taking into account the coupling of the rerrestrial and marine environmental-ecological processes.

Regional differences of urbanization in China and its driving factors

After more than 30 years of rapid urbanization, the overall urbanization rate of China reached 56.1% in 2015.However, despite China's rapid increase in its overall rate of urbanization, clear regional differences can be observed. Furthermore, inadequate research has been devoted to in-depth exploration of the regional differences in China's urbanization from a national perspective, as well as the internal factors that drive these differences. Using prefecture-level administrative units in China as the main research subject, this study illustrates the regional differences in urbanization by categorizing the divisions into four types based on their urbanization ratio and speed(high level: low speed; high level: high speed; low level: high speed; and low level: low speed). Next, we selected seven economic and geographic indicators and applied an ordered logit model to explore the driving factors of the regional differences in urbanization. A multiple linear regression model was then adopted to analyze the different impacts of these driving factors on regions with different urbanization types. The results showed that the regional differences in urbanization were significantly correlated to per capita GDP, industry location quotients, urban-rural income ratio,and time distance to major centers. In addition, with each type of urbanization, these factors were found to have a different driving effect. Specifically, the driving effect of per capita GDP and industry location quotients presented a marginally decreasing trend, while main road density appeared to have a more significant impact on cities with lower urbanization rates.