全球水资源危机不断凸显,水资源矛盾不断激化,国家（地区）间水政治关系已成为国际社会亟需面对和解决的复杂地缘关系之一。基于1948—2008年国际水事件数据库数据,以“嵌入型”视角从冲突、合作两个方面解构了全球水政治关系,并从网络关系特征和空间演化特征两个方面厘清了全球水政治格局的动态变化趋势。结果显示：①国家（地区）间水冲突网络与水合作网络热点区域在空间上发生了明显位移,水冲突网络热点由中亚向南亚、东南亚转移,而南亚、东南亚地区亦逐渐成为水合作的热点区;②国家（地区）间水冲突网络与水合作网络均表现为显著的核心—边缘结构,各个圈层间存在明显的更迭过程;③国家（地区）间水政治关系网络社团分化明显,相较于国家（地区）间水冲突的社团集聚模式,国家（地区）间水合作网络社团结构更为紧密,地理邻近特征更显著;④根据国家（地区）间水政治关系值,可将水政治双边关系分为紧张关系、友好关系和相对和缓关系。美洲地区前期水政治友好关系突出,东南亚国家后期水政治友好互动频繁,中东地区水政治关系较为紧张。

Global warming is accelerating the reshaping of the global natural and ecological environments. Water resources conflicts are intensifying, and hydro-political relations have become one of the most urgent and complex geo-relationships that countries and the international community need to face and handle. From the perspective of social networks, states’ hydro-political power is determined not only by the location, but also by the position of the hydro-political network. Based on the data of the International Water Event Database (IWED) from 1948 to 2008, the global hydro-political relationship was deconstructed from the perspective of conflict and cooperation and “embedded”, and the dynamics of global hydro-political structure were clarified from two aspects: network relationship characteristics and spatial evolution characteristics. The results show that: (1) Water conflict network and water cooperation network hotspots showed a significant spatial displacement. Water conflict network hotspots shifted from Central Asia to South Asia and Southeast Asia, while South Asia and Southeast Asia have gradually become the hotspots for water cooperation; (2) The inter-country water conflict network and the inter-country water cooperation network both showed obvious core-periphery structure, and there were obvious replacing processes among different circles; (3) The inter-country hydro-political relation network can be divided into several communities compared with the community agglomeration mode of water conflict among countries, the inter-country water cooperation network community structure is more compact, showing a broader geographical span; (4) The situation of international water political relations can be roughly divided into three stages: the tense stage of the 1940s and the 1970s, the quiet stage of the 1980s, and the stage of violent fluctuations after the 1990s. According to the value of inter-country hydro-political relations, the hydro-political bilateral relationship can be divided into in tension relationship, friendly relationship, and relatively stable relationship. International water events are mainly based on cooperation, and friendly relationships are the mainstream of bilateral relations in hydro-political relations.

全球地缘政治竞争回潮与资源环境危机推动国际河流水资源开发利用成为影响国家地缘安全的关键变量。通过对既有文献的梳理，发现国际河流水资源开发利用在“稀缺-冲突”范式下激化流域各国的矛盾，引发的水资源冲突联合域外势力进一步作用于国家地缘安全；在地缘安全视角下，中国国际河流的水资源开发利用经历了从“弱安全化”到“强安全化”再到“去安全化”的演进；水环境治理、水量分配及水开发利益协调是水资源开发利用中的核心议题，涉及的跨境水资源污染、水权分配以及水电开发争议等问题与国家地缘安全密切相关；东北、西北及西南三大国际河流密集区水资源开发利用方式地域分异明显，在差异化的地缘环境下带来多元的地缘安全威胁；最后基于“一带一路”及“人类命运共同体”等背景对中国未来外交提出建议。

被喻为“亚洲水塔”的青藏高原，是亚洲多条国际大河的发源地。全球气候变暖导致青藏高原冰川消融，进而引起周边河流长期径流的下降和季节分配的紊乱。这一自然变化叠加在流域内国家社会经济快速发展等人文变迁过程之上，造成水资源的供给与需求在总量及时间匹配上的失衡与错位，从而在该地区诱发更多水冲突、水危机等水政治问题。域外大国的介入则进一步加剧了本地区水政治的复杂性，并已在事实上威胁到中国与周边国家的战略互信。未来，中国应以包容互鉴、合作共赢的“丝路精神”为指引，基于既有国际规范，通过多边或双边谈判寻求化解水冲突，促进与相关国家的利益融合及流域国家命运共同体的实现。

探讨澜沧江流域旱涝特征变化与季风之间的关联性,对于区域旱涝灾害的成因、机理和预测等重大科学问题的理解具有重要的意义。区域研究多侧重于揭示流域旱涝时空演变规律,而关于澜沧江流域的旱涝与季风的相互关系研究还较少。基于标准化降水指数(SPI12)、季风指数和水汽通量对澜沧江流域1957—2015年旱涝时空变化特征进行分析,探究澜沧江流域旱涝变化与季风指数的相互关系,并从水汽通量输送角度出发,进一步揭示季风对澜沧江流域旱涝变化影响的潜在驱动机制。研究结果表明:①流域旱涝特征具有明显的区域差异,下游区域是旱涝多发区;②流域干旱多于雨涝,且干旱频次在年和季节时间尺度上都呈现增加变化趋势;③澜沧江流域干旱和雨涝的频次主要存在3~5,8~15,20~25 a的3种周期性变化特征;④干旱和雨涝发生时段,南亚季风和高原季风指数与流域的SPI12指数相关性较强,受南亚季风和高原季风的输送距离影响,2种季风指数与SPI12指数的相互关系呈现区域差异性。研究结果有助于了解澜沧江流域旱涝时空变化特征,能够为防御旱涝灾害提供科学决策依据。

Studying the connections between drought/flood characteristics and monsoons in the Lancang River basin is of vital significance for understanding the causes, mechanisms and prediction of regional drought/flood disasters; yet the vast majority of existing studies are focused on the temporal and spatial evolution characteristics of drought/flood rather than on the connections between drought/flood characteristics and monsoons in the Lancang River basin. In this paper, the temporal and spatial changes in characteristics of drought/flood in 1957-2015 are investigated in terms of standard precipitation index (SPI12), monsoon index, and water vapor flux; the connections between drought/flood changes and monsoon index are examined, and the mechanism of drought/flood changes driven by monsoons and water vapor fluxes is further revealed. Results indicated that: (1) flood/drought has obvious regional difference, and the downstream area is prone to flood and drought; (2) the frequency of drought is superior to that of flood, showing an increasing trend in annual and seasonal time scales; (3) the frequencies of flood and drought mainly varied periodically at 3-5 years, 8-15 years, and 20-25 years; (4) in drought/flood period, indices of the South Asian monsoon and the Plateau monsoon have relatively strong correlations with the standard precipitation index (SPI12) in the Lancang River basin; such correlation varies in different regions due to the limited transportation distance of monsoons. The results are helpful in understanding the temporal and spatial change characteristics of drought/flood in the Lancang River basin, and also offer scientific basis for the decision-making of drought/flood prevention.

洞里萨湖是湄公河最大的连通湖泊,其水位、面积变化对洞里萨湖的结构和功能产生重要影响,辨识水位、面积演变规律对洞里萨湖区与湄公河三角洲防汛抗旱和生态环境保护具有重要指导意义。基于金边港、波雷格丹和甘邦隆站长系列的日均水位数据及湖区地形资料,定量分析了洞里萨湖水位、面积的年际与年内变化特征。结果表明:洞里萨湖水位涨落缓慢,涨水天数少于退水天数,涨水率高于落水率。洞里萨湖年际水位波动频繁,年平均水位、年最高水位、年水位极差值、年洪水历时、年平均洪水位、日涨水率年际变化总体呈小幅下降趋势,年最低水位、退水天数、日落水率年际变化呈上升趋势。洞里萨湖水位、面积年内呈单峰型变化,5月份最低,平均水位1.51 m,相应面积2 487 km²,实测最低水位1.11 m,相应面积2 053 km²;10月份最高,平均水位8.70 m,相应面积12 768 km²,实测最高水位为10.54 m,相应面积15 261 km²,多年平均年内水位变幅7.63 m,面积变幅10 628 km²。研究成果为下一步洞里萨湖区的综合治理规划奠定了基础。

Tonle Sap Lake is the largest lake linked with Mekong River. The variations of water level and area exert vital impact on the structure and function of Tonle Sap Lake. Identifying the evolvement rule of water level and area is of guiding significance for flood control and drought relief as well as eco-environmental protection in Tonle Sap Lake and the Mekong Delta. According to long series of daily water level data of Phnom Penh Port, Prek Kdam and Kampong Luong stations and topographic data of lake area, we analyzed the inter-annual and annual variations of water level and area of Tonle Sap Lake. Results reveal that the water level of Tonle Sap Lake raise and fell slowly, with the rising duration shorter than falling duration and rising rate higher than falling rate. The water level of Tonle Sap Lake fluctuated frequently between years, with the annual average water level, annual maximum water level, annual water level range, annual flood duration, annual average flood level and daily rising rate all showing slight downward trend, while the annual lowest water level, water withdrawal days and daily falling rate showing upward trend. The annual water level and area of Tonle Sap Lake changed with a single peak value. The lowest water level was in May, when the average water level was 1.51 m and the corresponding area 2 487 km², the measured minimum water level 1.11 m and the corresponding area 2 053 km²; the water level reached the maximum value in October, when the average water level was 8.70 m and the corresponding area 12 768 km², the measured maximum water level 10.54 m and the corresponding area 15 261 km². Multi-year average water level range of Tonle Sap Lake was 7.63 m and the corresponding area range was 10 628 km².

澜沧江作为亚洲最重要的跨国水系,是“亚洲水塔”的重要组成部分。分析澜沧江上游河川径流的演变规律与变化趋势,对澜沧江水资源利用与区域绿色能源发展具有重要的战略意义。基于乌弄龙断面径流资料与上游气温、降水资料,采用线性倾向估计、Mann-Kendall 趋势检验和Pearson相关系数等方法对近30 a澜沧江上游径流演变特征进行分析。结果表明,自有径流资料以来,澜沧江上游径流在年代际尺度上变化不大,但在季节上表现为冬季径流增加,夏季径流减少的特点,其中8月份径流在20世纪70年代初存在突变,并以4.8%/(10 a)的显著趋势下降,折合水量2.0亿m³/(10 a),且近30 a下降速率还在进一步加快,上游中部地区降水量减少与径流减少的趋势一致。研究还发现,近30 a以来,随着春季气温升高,上游径流对5月份气温的响应有所减弱,而4月份两者的关系变得密切。在全球变暖的大背景下,澜沧江上游融雪(冰)期逐渐提前,需要引起高度重视,并采取积极应对措施。

As the most important transnational water system in Asia, the Lancang River plays a crucial role as part of the “Asian Water Tower”. Analyzing the evolutionary patterns and trends of upstream river runoff in the Lancang River has significant strategic implications for water resource utilization and regional green energy development. The present study focuses on the runoff characteristics and their evolution in the upstream of Lancang River over the past 30 years based on data from the Wunonglong section, as well as air temperature and precipitation records. Methodologies including linear regression analysis, the Mann-Kendall trend test, and Pearson correlation coefficient were employed for data analysis. The findings reveal that, over the decades since the availability of discharge data, the upstream runoff in the Lancang River has exhibited little change at the decadal scale. However, on a seasonal basis, there is a tendency of increased runoff in winter and decreased runoff in summer. Notably, a distinct shift occurred in August in the early 1970s, with a prominent decreasing trend of 4.8% per decade, approximately equivalent to a total volume reduction of 200 million cubic meters per decade. Moreover, this decreasing trend has been further accelerating in the past 30 years, consistent with the decreasing trend of precipitation in the middle region of the upstream area. The study also reveals that, over the past three decades, as spring temperatures have risen, the response of upstream runoff to temperature in May has weakened, while the relationship between temperature in April and runoff has become more pronounced. Given the background of global warming, the advancing snowmelt period in the upstream area of the Lancang River requires high attention and proactive measures.

作为连接六国的跨境河流,澜沧江—湄公河（澜湄）流域的径流变化与流域内各国以及相关地区的社会经济发展和生产生活方式密切相关。为深入了解澜湄流域地表水资源的时空变化特性及主要影响因素,本文基于1961—2015年澜湄流域气象水文资料,分析了澜湄流域径流变化趋势和突变特征,构建了体现澜湄流域特性的SWAT水文模型,定量评估了气候变化和人类活动对澜湄流域径流变化的影响。主要结论为：①年尺度上,澜湄流域径流在旧州站变化趋势不明显,在允景洪站呈显著下降趋势,在万象和上丁站呈先下降后上升趋势;季节尺度上,各水文站旱、雨季径流变化趋势与年尺度基本一致,旱季径流量变化幅度较小,雨季径流量变化幅度较大。②1998—2000年为全流域径流发生突变的集中期,因此将各区域径流的变化期划分为2000年之前和之后两部分。③气候变化对澜湄流域径流的影响程度自上游到下游逐渐减小,人类活动的影响程度则逐渐加大,且人类活动对旱季径流的影响程度大于雨季。本文结果有助于了解澜湄流域水资源现状和变化趋势,为澜湄流域水资源合理利用以及“一带一路”沿线国家的社会经济可持续发展提供参考和借鉴。

As a cross-border river that connects six countries, the streamflow changes of the Lancang-Mekong River Basin (LMRB) are closely related to the socioeconomic development and production and life style of the countries in this basin. In order to systematically understand the changes of surface water resources in the LMRB, this study analyzed the trend and abrupt change characteristics of streamflow and quantitatively determined the influence of climate and human activities on streamflow in the basin based on the streamflow and meteorological data from 1961 to 2015. The main conclusions are as follows: (1) At the annual scale, the streamflow of the Jiuzhou Station didn’t show a significant trend from 1961-2010. However, there was a significant decreasing trend at the Yunjinghong Station from 1961-2014. The average streamflow of the Vientiane Station and the Stung Treng Station both showed a trend from decline to rise. At the seasonal scale, the variation trend of streamflow was consistent with that at the annual scale in both the dry and rainy seasons. The variation range of streamflow was small in the dry season but large in the rainy season. (2) The main period of abrupt change occurred in 1998-2000, so the streamflow change period of the four areas (Jiuzhou above, Jiuzhou-Yunjinghong, Yunjinghong-Vientiane, and Vientiane-Stung Treng basins) was divided into before and after 2000. (3) The impact of climate change on streamflow in the LMRB decreased from the upper reaches to the lower reaches (except the delta region) and the impact of human activities increased gradually. The impact of human activities on streamflow in the dry season was greater than that in the rainy season. The variation of streamflow was mainly affected by precipitation in the LMRB while the streamflow at the Stung Treng Station was mainly affected by human activities after 2000.