江河源区生态环境范围的探讨

The Tibetan Plateau, as the origin of the Yangtze and Yellow rivers, is the region of climate variation and is very sensitive to climate change in China (Feng etal., 1998). The runoff in the upper reaches of the Yellow River has been decreasing at a rate of 9.8 m3/s per decade due to rapid climate warming in the Tibetan Plateau since the mid- and late 1980s (Zhang etal., 2000). Eco-environmental change is also extremely substantial in the source regions of the Yangtze and Yellow rivers. T…     

三江源地区气候变化及其对径流的驱动分析(英文)

Based on the precipitation and temperature data of the 12 meteorological stations in the "Three-River Headwaters" region and the observed runoff data of Zhimenda in the headwater sub-region of the Yangtze River, Tangnaihai in the headwater sub-region of the Yellow River and Changdu in the headwater sub-region of the Lancang River during the period 1965-2004, this paper analyses the trends of precipitation, temperature, runoff depth and carries out significance tests by means of Mann-Kendall-Sneyers sequential trend test. Makkink model is applied to calculate the potential evaporation. The runoff model driven by precipitation and potential evaporation is developed and the influence on runoff by climate change is simulated under different scenarios. Results show that during the period 1965-2004 the temperature of the "Three-River Headwaters" region is increasing, the runoff of the three hydrological stations is decreasing and both of them had abrupt changes in 1994, while no significant trend changes happen to the precipitation. The runoff model suggests that the precipitation has a positive effect on the runoff depth, while the potential evaporation plays a negative role. The influence of the potential evaporation on the runoff depth of the Lancang River is found to be the significant in the three rivers; and that of the Yellow River is the least. The result of the scenarios analysis indicates that although the precipitation and the potential evaporation have positive and negative effects on runoff relatively, fluctuated characteristics of individual effect on the runoff depth in specific situations are represented.     

三江源区径流演变及其对气候变化的响应(英文)

Runoff at the three time scales(non-flooding season,flooding season and annual period) was simulated and tested from 1958 to 2005 at Tangnaihai(Yellow River Source Region:YeSR),Zhimenda(Yangtze River Source Region:YaSR) and Changdu(Lancang River Source Region:LcSR) by hydrological modeling,trend detection and comparative analysis.Also,future runoff variations from 2010 to 2039 at the three outlets were analyzed in A1B and B1 scenarios of CSIRO and NCAR climate model and the impact of climate change was tested.The results showed that the annual and non-flooding season runoff decreased significantly in YeSR,which decreased the water discharge to the midstream and downstream of the Yellow River,and intensified the water shortage in the Yellow River Basin,but the other two regions were not statistically significant in the last 48 years.Compared with the runoff in baseline(1990s),the runoff in YeSR would decrease in the following 30 years(2010-2039),especially in the non-flooding season.Thus the water shortage in the midstream and downstream of the Yellow River Basin would be serious continuously.The runoff in YaSR would increase,especially in the flooding season,thus the flood control situation would be severe.The runoff in LcSR would also be greater than the current runoff,and the annual and flooding season runoff would not change significantly,while the runoff variation in the non-flooding season is uncertain.It would increase significantly in the B1 scenario of CSIRO model but decrease significantly in B1 scenario of NCAR model.Furthermore,the most sensitive region to climate change is YaSR,followed by YeSR and LcSR.     

皇甫川流域降水量和人类活动对径流量变化影响的定量评估(英文)

The runoff of some rivers in the world especially in the arid and semi-arid areas has decreased remarkably with global or regional climate change and enhanced human activities.The runoff decrease in the arid and semi-arid areas of northern China has brought severe problems in livelihoods and ecology.To reveal the variation characteristics,trends of runoff and their influencing factors have been important scientific issues for drainage basin management.The objective of this study was to analyze the variation trends of the runoff and quantitatively assess the contributions of precipitation and human activities to the runoff change in the Huangfuchuan River Basin based on the measured data in 1960-2008.Two inflection points(turning years) of 1979 and 1998 for the accumulative runoff change,and one inflection point of 1979 for the accumulative precipitation change were identified using the methods of accumulative anomaly analysis.The linear relationships between year and accumulative runoff in 1960-1979,1980-1997 and 1998-2008 and between year and accumulative precipitation in 1960-1979 and 1980-2008 were fitted.A new method of slope change ratio of accumulative quantity(SCRAQ) was put forward and used in this study to calculate the contributions of different factors to the runoff change.Taking 1960-1979 as the base period,the contribution rate of the precipitation and human activities to the decreased runoff was 36.43% and 63.57% in 1980-1997,and 16.81% and 83.19% in 1998-2008,respectively.The results will play an important role in the drainage basin management.Moreover,the new method of SCRAQ can be applied in the quantitative evaluation of runoff change and impacts by different factors in the river basin of arid and semi-arid areas.     

1950–2011年黄河入海水沙通量变化的阶段性与多尺度特征(英文)

This paper examines the changes in the time series of water discharge and sediment load of the Yellow River into the Bohai Sea. To determine the characteristics of abrupt changes and multi-scale periods of water discharge and sediment load, data from Lijin station were analyzed, and the resonance periods were then calculated. The Mann-Kendall test, order clustering, power-spectrum, and wavelet analysis were used to observe water discharge and sediment load into the sea over the last 62 years. The most significant abrupt change in water discharge into the sea occurred in 1985, and an abrupt change in sediment load happened in the same year. Significant decreases of 64.6% and 73.8% were observed in water discharge and sediment load, respectively, before 1985. More significant abrupt changes in water discharge and sediment load were observed in 1968 and 1996. The characteristics of water discharge and sediment load into the Bohai Sea show periodic oscillation at inter-annual and decadal scales. The main periods of water discharge are 9.14 years and 3.05 years, whereas the main periods of sediment load are 10.67 years, 4.27 years, and 2.78 years. The significant resonance periods between water discharge and sediment load are observed at the following temporal scales: 2.86 years, 4.44 years, and 13.33 years. Water discharge and sediment load started to decrease after 1970 and has decreased significantly since 1985 for several reasons. Firstly, the precipitation of the Yellow River drainage area has reduced since 1970. Secondly, large-scale human activities, such as the building of reservoirs and floodgates, have increased. Thirdly, water and soil conservation have taken effect since 1985.     

Impacts of climate change and LULC change on runoff in the Jinsha River Basin

The climate change and Land Use/Land Cover(LULC) change both have an important impact on the rainfall-runoff processes. How to quantitatively distinguish and predict the impacts of the above two factors has been a hot spot and frontier issue in the field of hydrology and water resources. In this research, the SWAT(Soil and Water Assessment Tool) model was established for the Jinsha River Basin, and the method of scenarios simulation was used to study the runoff response to climate change and LULC change. Furthermore, the climate variables exported from 7 typical General Circulation Models(GCMs) under RCP4.5 and RCP8.5 emission scenarios were bias corrected and input into the SWAT model to predict runoff in 2017–2050. Results showed that:(1) During the past 57 years, the annual average precipitation and temperature in the Jinsha River Basin both increased significantly while the rising trend of runoff was far from obvious.(2) Compared with the significant increase of temperature in the Jinsha River Basin, the LULC change was very small.(3) During the historical period, the LULC change had little effect on the hydrological processes in the basin, and climate change was one of the main factors affecting runoff.(4) In the context of global climate change, the precipitation, temperature and runoff in the Jinsha River Basin will rise in 2017–2050 compared with the historical period. This study provides significant references to the planning and management of large-scale hydroelectric bases at the source of the Yangtze River.     

自然地理格局对区域发展时空分异影响的评价方法

With the rapid economic development during the last 30 years in China, more and more disparities have emerged among different regions. It has been one of the hot topics in the fields of physical geography and economic geography, and also has been the task for Chinese government to handle. Nevertheless, to quantitatively assess the impacts of physio-geographical patterns （PGP） on the regional development disparity has been ignored for a long time. In this paper, a quantitative method was adopted to assess the marginal effects of the PGP on spatio-temporal disparity using the partial determination coefficients. The paper described the construction of the evaluation model step by step following its key scientific thinking. Total GDP, per capita GDP, primary industrial output value and secondary industrial output value were employed in this study as the indicators to reflect the impacts of PGP on the regional development disparity. Based on the evaluation methods built by researchers, this study firstly analyzed the temporal impacts of the PGP on spatio-temporal disparity of the regional development in China during the past 50 years, and then explained the spatial differences at each development stage. The results show that the spatio-temporal disparity in China is highly related to the PGP, and that the marginal contribution rate could be employed as an effective way to quantitatively assess the impact of the PGP on spatio-temporal disparity of the regional development.     

Climate transformation to warm-humid and its effect on river runoff in the source region of the Yellow River

The change characteristics and trends of the regional climate in the source region of the Yellow River, and the response of runoff to climate change, are analyzed based on observational data of air temperature, precipitation, and runoff at 10 main hydrological and weather stations in the region. Our results show that a strong signal of climate shift from warm-dry to warm-humid in the western parts of northwestern China （Xinjiang） and the western Hexi Corridor of Gansu Province occurred in the late 1980s, and a same signal of climate change occurred in the mid-2000s in the source region of the Yellow River located in the eastern part of northwestern China. This climate changeover has led to a rapid increase in rainfall and stream runoff in the latter region. In most of the years since 2004 the average annual precipitation in the source region of the Yellow River has been greater than the long-term average annual value, and after 2007 the runoff measured at all of the hydrologic sections on the main channel of the Yellow River in the source region has also consistently exceeded the long-term average annual because of rainfall increase. It is difficult to determine the prospects of future climate change until additional observations and research are conducted on the rate and temporal and spatial extents of climate change in the region. Nevertheless, we predict that the climate shift from warm-dry to warm-humid in the source region of the Yellow River is very likely to be in the decadal time scale, which means a warming and rainy climate in the source region of the Yellow River will continue in the coming decades.     

江河源区NDVI时空变化及其与气候因子的关系(英文)

The source regions of the Yangtze and Yellow rivers are important water conservation areas of China. In recent years, ecological deterioration trend of the source regions caused by global climate change and unreasonable resource development increased gradually. In this paper, the spatial distribution and dynamic change of vegetation cover in the source regions of the Yangtze and Yellow rivers are analyzed in recent 10 years based on 1-km resolution multitemporal SPOTVGT-DN data from 1998 to 2007. Meanwhile, the correlation relationships between air temperature, precipitation, shallow ground temperature and NDVI, which is 3×3 pixel at the center of Wudaoliang, Tuotuohe, Qumalai, Maduo, and Dari meteorological stations were analyzed. The results show that the NDVI values in these two source regions are increasing in recent 10 years. Spatial distribution of NDVI which was consistent with hydrothermal condition decreased from southeast to northwest of the source regions. NDVI with a value over 0.54 was mainly distributed in the southeastern source region of the Yellow River, and most NDVI values in the northwestern source region of the Yangtze River were less than 0.22. Spatial changing trend of NDVI has great difference and most parts in the source regions of the Yangtze and Yellow rivers witnessed indistinct change. The regions with marked increasing trend were mainly distributed on the south side of the Tongtian River, some part of Keqianqu, Tongtian, Chumaer, and Tuotuo rivers in the source region of the Yangtze River and Xingsuhai, and southern Dari county in the source region of the Yellow River. The regions with very marked increasing tendency were mainly distributed on the south side of Tongtian Rriver and sporadically distributed in hinterland of the source region of the Yangtze River. The north side of Tangula Range in the source region of the Yangtze River and Dari and Maduo counties in the source region of the Yellow River were areas in which NDVI changed with marked decreasing tendency. The NDVI change was980 Journal of Geographical Sciences positively correlated with average temperature, precipitation and shallow ground temperature. Shallow ground temperature had the greatest effect on NDVI change, and the second greatest factor influencing NDVI was average temperature. The correlation between NDVI and shallow ground temperature in the source regions of the Yangtze and Yellow rivers increased significantly with the depth of soil layer.     

Impacts of climate change on glacial water resources and hydrological cycles in the Yangtze River source region, the Qinghai-Tibetan Plateau, China: A Progress Report

The Yangtze River Source Region has an area of 137,704 km2.Its mean annual runoff of 12.52 billion m3,which was recorded by the Chumda Hydrological Station in 1961-2000,accounts for only 0.13 percent of the Yangtze River’s total annual streamflow.The extensive rivers,lakes,wetlands,glaciers,snow fields,and permafrost of the Yangtze River Source Region,as well as the region’s vast alpine grasslands,play a critical role in storing and regulating the flow of water not only in the upper Yangtze River watershed of Qinghai,Sichuan,the Tibet Autonomous Region (TAR) (Tibet) and Yunnan,but also throughout the entire lower Yangtze River basin.Climate change has been the dominant factor in recent fluctuation in the volume of the Yangtze River Source Region’s glacier resources.The Chumda Hydrological Station on the lower Tongtian River has registered a mean annual glacial meltwater of 1.13 billion m3 for the period 1961-2000,makes up 9 percent of the total annual runoff.Glacial meltwater makes up a significant percentage of streamflow in the Yangtze River Source Region,the major rivers of the upper Yangtze River Source Region:the Togto,Dam Chu,Garchu,and Bi Chu (Bu Chu) rivers all originate at large glaciers along the Tanggula Range.Glaciers in the Yangtze River Source Region are typical continental-type glaciers with most glacial meltwater flow occurring June-August;the close correlation between June-August river flows and temperature illustrates the important role of glacial meltwater in feeding rivers.Glaciers in the source region have undergone a long period of rapid ablation beginning in 1993.Examination of flow and temperature data for the 1961-2000 period shows that the annual melting period for glacial ice,snow,and frozen ground in the Yangtze River Source Region now begins earlier because of increasing spring temperatures,resulting in the reduction of summer flood season peak runoffs;meanwhile,increased rates of glacier ablation have resulted in more uneven annual distribution of runoff in the source region.T     

水电开发对河流水沙特性影响的综合评价方法

选取已连续25 年大规模水电开发的澜沧江为研究对象,建立了河流水沙特性受影响程度评价指标体系及指标回归还原模型,并采用层次分析法和因子分析法相结合的赋权方法确定指标权重;借鉴“边际效益”原理,结合基于河流水沙自然变幅确立的指标评价标准,建立了各指标受影响程度定量评价模型。利用所建立的方法与模型,综合定量评价了澜沧江水沙特性的受影响程度,结果表明：澜沧江水电开发以来(1986-2007 年),河流水沙特性总体受影响程度等级为很小的年数占72.7%,为较小的年数占18.2%,为一般的年数占9.1%,输沙受影响程度远大于径流;水沙特性受影响的变化过程呈“U”形,其主要原因是在漫湾水电站运行与大朝山水电站建设并存期,库区拦沙作用与电站施工增沙作用使输沙趋于平衡。本研究,为后续相关研究提供方法借鉴,为评估水电开发对澜沧江水沙特性影响提供新的依据。     

澜沧江水资源系统变化与大湄公河次区域合作的关联分析

针对澜沧江-湄公河水资源系统变化的跨境影响这一受到国际社会,特别是下游国关注的问题,结合流域各国水需求及区域性协定之规定,对比分析澜沧江大坝建设后对径流的影响,发现：（1）年出境水量呈小幅增长趋势,总体上有利于下游水资源利用;（2）个别年份枯季出境水量明显减少的主要原因是降水少和个别电站运行失误所致,电站本质上不会对下游用水和生态产生实质性危害;（3）出境水量变化主要对下游中上段产生明显影响,越往下游影响力越小;（4）出境水质稳定。建议：尽早制定流域综合规划和国际水分配方案;合理调整水库运行方案,避免出境水量或水位的大幅变化,减少跨境负面影响,维护区域合作。     

Sediment-related impacts due to upstream reservoir trapping, the Lower Mekong River

A sharp decrease in total suspended solids (TSS) concentration has occurred in the Mekong River after the closure of the Manwan Dam in China in 1993, the first of a planned cascade of eight dams. This paper describes the upstream developments on the Mekong River, concentrating on the effects of hydropower dams and reservoirs. The reservoir-related changes in total suspended solids, suspended sediment concentration (SSC), and hydrology have been analyzed, and the impacts of such possible changes on the Lower Mekong Basin discussed. The theoretical trapping efficiency of the proposed dams has been computed and the amount of sediment to be trapped in the reservoirs estimated. The reservoir trapping of sediments and the changing of natural flow patterns will impact the countries downstream in this international river basin. Both positive and negative possible effects of such impacts have been reviewed, based on the available data from the Mekong and studies on other basins.     

澜沧江河床沉积物重金属污染评价

河床沉积物是河流水体与泥沙环境中重金属的主要积存载体,能反映水环境的重金属污染状况。本文选取澜沧江为对象,通过对澜沧江干流西藏和云南境内22个河段的河床沉积物重金属测定分析,得到了8种主要的重金属元素(Cr、Mn、Ni、Zn、As、Pb、Cu和Co)的含量,并采用沉积物富集系数法与地质积累指数法分别对所测得沉积物的重金属污染程度进行了评价。结果表明:①澜沧江干流大部分河段污染情况并不明显,但在中游的旧州和功果桥河段,因该区域的地质金属背景值和支流沘江流域铅锌矿开采,地表的重金属元素被雨水冲刷到该河段,导致沉积物重金属富集现象明显,出现了轻度到较强度污染;②澜沧江流域受人为干扰的区域集中于中游与下游,部分河段(功果桥附近)Cu、Pb和Zn等元素呈轻度或偏中度污染;③大坝对河流的阻隔效应使得干流沉积物重金属污染呈现片段化分布,河流沿岸城市化等人类活动对附近河段沉积物重金属污染状况也有较明显的影响。     

中国国际河流研究热点与前沿的可视化分析

随着全球气候变化及淡水资源紧张,国际河流逐渐成为国际社会关注的热点和焦点。为探寻中国学者对国际河流问题的研究热点与前沿方向,基于CNKI数据库中1957—2019年的2391篇中文文献,运用CiteSpaceⅤ等工具进行文献分析和数据挖掘。结果表明：近60年来中国学者在国际河流领域的研究经历了探索起步、较快发展、全面增长、成熟发展四个阶段,研究规模和学术影响力呈现良好发展态势;主体研究力量集中于少数优势机构,跨地域、跨机构间的合作较少,机构间的联合攻关和合作网络有待加强;发文期刊从自然科学向综合社科领域扩散,国际河流问题研究的多学科、多维度、多视角特征日益明显;从地域范围上,中国西南、东北、西北三大地区的国际河流普遍受到关注,西南地区为持续重点关注区,西北地区关注热度明显上升。研究热点和前沿呈现“水电开发—次区域合作—气候变化与生态环境—一带一路—澜湄合作”的演进特征,最近十年研究热点为气候变化影响下的国际河流水资源和水生态及“一带一路”背景下的涉水合作问题。     

基于Copula函数的洞庭湖流域水沙丰枯遭遇频率分析

受人类活动的影响,水沙灾害事件相继发生,对人们的生产、生活造成了威胁。以洞庭湖流域代表性水文站的年径流量和年输沙量系列数据为基础,应用P-III型曲线分别拟合并求得“松滋口、太平口、藕池口”三口入湖、“湘江、资江、沅水、澧水”四水入湖和城陵矶站出湖年径流量、年输沙量的边缘分布函数,再采用水文事件遭遇分析中广泛应用的Copula函数,建立洞庭湖流域水沙联合分布模型,分析洞庭湖流域水沙丰枯遭遇频率。研究结果表明洞庭湖三口、四水和城陵矶站的水沙丰枯遭遇频率关系与洞庭湖流域的水沙运动有密切联系,运用该水沙耦合模型可以为洞庭湖流域防洪减灾提供重要的理论依据。     

澜沧江中上游鱼类生物多样性现状初报

对澜沧江上游及支流的鱼类和环境调查显示流域片段化对鱼类生物多样性产生了较大的影响。从漾濞江和西洱河的比较可以看出,前者因为没有梯级电站,鱼类的种类和数量并无太大的变化,而西洱河由于过度的梯级开发和污染,鱼类濒于灭绝,洱海由于江湖的隔绝,外来种的引入使得土著鱼类种群数量急剧减少。干流上大坝（漫湾水电站）的修建使得流水变为静水环境而产生一系列的变化使鱼类的种类和种群数量产生变化。     

2000-2017年河龙区间输沙量锐减归因分析

2000年以来,黄河输沙量锐减。科学认识黄河输沙量变化原因,具有重要意义。以河龙区间为研究对象,分析了河龙区间输沙量变化趋势,构建了梯田、淤地坝以及植被等大规模生态建设措施的减沙贡献率计算方法,阐述了2000-2017年河龙区间输沙量锐减原因,针对河龙区间输沙量变化趋势和治理格局,提出了河龙区间治理对策。主要结论为：① 1952-2017年,河龙区间年降水量无显著变化趋势,研究区年输沙量呈现极显著减少趋势（p < 0.001）;② 1979年和1999年为研究区输沙量发生突变的两个时间节点（p < 0.05）,1952-1979年区间年均输沙量为9.30亿t,1980-1999年区间年均输沙量为4.20亿t,2000-2017年均输沙量大幅降至1.03亿t,降幅达89%;③ 受植被和梯田共同影响,2000-2015年研究区坡面土壤侵蚀量变化介于1.90亿~5.13亿t之间,且呈下降趋势;2000-2011年河龙区间淤地坝年均拦沙量为1.38亿t;④ 植被恢复是河龙区间输沙量减少的主要原因,贡献率为54%,梯田和淤地坝合计贡献了34%,水库拦沙和引水取沙贡献了12%;⑤ 植被恢复主要导致径流含沙量降低,而淤地坝建设主要降低了流域泥沙输移比。