可可西里盐湖湖水外溢可能性初探

2011年9月可可西里地区卓乃湖溃决后,关于盐湖湖水能否外溢进入楚玛尔河继而成为长江的最北源是公众及学界普遍关注的话题。本研究基于2010-2015年Landsat TM/ETM+/OLI遥感影像、SRTM 1弧秒数据、Google Earth高程数据和五道梁气象台站观测数据,首次对盐湖变化、湖水外溢条件及其可能性进行分析。结果表明：卓乃湖溃决后,盐湖在2011年10月至2013年4月期间面积急剧增加,之后湖泊进入稳定扩张期,2015年10月27日盐湖面积为151.38 km²,是2010年3月3日湖泊面积的3.35倍。盐湖发生湖水外溢的条件是湖泊面积达到218.90~220.63 km²。由于SRTM和Google Earth高程数据间的差异,盐湖湖水外溢时的水位将比当前高12 m或9.6 m,相应湖泊库容增加23.71 km³或17.27 km³,届时湖水将由湖泊东侧流入清水河流域。尽管盐湖在未来10年内不可能发生湖水外溢,但是随着盐湖集水区的扩大及预估的区域未来降水量的增加,在更长时间尺度内盐湖发生湖水外溢并成为长江支流的可能性依然存在。     

Spatial-temporal characteristics of lake area variations in Hoh Xil region from 1970 to 2011

As one of the areas with numerous lakes on the Tibetan Plateau, the Hoh Xil region plays an extremely important role in the fragile plateau eco-environment. Based on topographic maps in the 1970s and Landsat TM/ETM+ remote sensing images in the 1990s and the period from 2000 to 2011, the data of 83 lakes with an area above 10 km² each were obtained by digitization method and artificial visual interpretation technology, and the causes for lake variations were also analyzed. Some conclusions can be drawn as follows. (1) From the 1970s to 2011, the lakes in the Hoh Xil region firstly shrank and then expanded. In particular, the area of lakes generally decreased during the 1970s–1990s. Then the lakes expanded from the 1990s to 2000 and the area was slightly higher than that in the 1970s. The area of lakes dramatically increased after 2000. (2) From 2000 to 2011, the lakes with different area ranks in the Hoh Xil region showed an overall expansion trend. Meanwhile, some regional differences were also discovered. Most of the lakes expanded and were widely distributed in the northern, central and western parts of the region. Some lakes were merged together or overflowed due to their rapid expansion. A small number of lakes with the trend of area decrease or strong fluctuation were scattered in the central and southern parts of the study area. And their variations were related to their own supply conditions or hydraulic connection with the downstream lakes or rivers. (3) The increase in precipitation was the dominant factor resulting in the expansion of lakes in the Hoh Xil region. The secondary factor was the increase in meltwater from glaciers and frozen soil due to climate warming.     

青海可可西里主要湖泊湖底地貌研究

应用阈值法对青海可可西里地区主要湖泊的遥感影像进行水体信息提取,根据水体与其它地物在ETM+的5波段具有很好的区分效果,经反复尝试在该波段找到了适合各个湖泊的分离阈值。通过目视解读,并与相关地形图对比检验,湖泊水体可较为准确提取出。利用ENVI软件得到包含湖底信息的合成图像,选择其中信息丰富的假彩色合成图像进行解译,根据其色调并结合近岸地形信息初步判断出了湖底的地形地势,并在永红湖底发现了一个特殊的环状构造。     

近40 年可可西里地区湖泊时空变化特征

以可可西里地区1970s 地形图和1990s、2000-2011 年Landsat TM/ETM+遥感影像为基础,通过数字化和影像解译获取研究区83 个面积大于10 km²湖泊变化数据,并对湖泊变化成因进行了分析。研究结果表明:1) 1970s 初期至2011 年,可可西里地区湖泊经历了“先萎缩后扩张”的变化过程,其中1970s-1990s 期间湖泊面积普遍减小,1990s-2000 年湖泊出现扩张,并在2000 年恢复到1970s 湖泊规模,2000 年之后湖泊面积急剧增大。2) 2000-2011 年间,可可西里地区不同规模等级湖泊整体呈扩张趋势,但表现出一定的区域差异性。面积呈增加趋势的湖泊数量最多,亦分布最广,一些湖泊由于扩张迅速出现湖泊合并或湖水外泄情况;面积呈减少趋势或波动起伏的湖泊数量较少,零散分布在研究区中部和南部,湖泊动态变化与其自身补给条件或与下游湖泊(河道) 存在水力联系有关。3) 在研究时段内,降水增多、蒸发减少是可可西里地区湖泊扩大的主要原因,而气候变暖引起的冰川融水增加、冻土水分释放是次要原因。     

Modeling the history of Lake of the Woods since 11,000 cal yr B.P. using GIS

Because of differential isostatic rebound, many lakes in Canada have continued to change their extent and depth since retreat of the Laurentide Ice Sheet. Using GIS techniques, the changing configuration and bathymetry of Lake of the Woods in Ontario, Manitoba, and Minnesota were reconstructed for 12 points in time, beginning at 11,000 cal yr B.P. (9.6 ¹⁴C ka B.P.), and were also projected 500 years into the future, based on the assumption that Lake of the Woods continued to have a positive hydrological budget throughout the Holocene. This modeling was done by first compiling a bathymetric database and merging that with subaerial data from the Shuttle Radar Topography Mission (SRTM). This DEM file was then adjusted by: (1) isobase data derived from Lake Agassiz beaches prior to 9000 cal yr B.P. (8.1 ¹⁴C ka B.P.) and (2) modeled isostatic rebound trend analysis after 9000 cal yr B.P. Just after the end of the Lake Agassiz phase of Lake of the Woods, only the northernmost part of the basin contained water. Differential rebound has resulted in increasing water depth. In the first 3000 years of independence from Lake Agassiz, the lake transgressed >50 km to the south, expanding its area from 858 to 2857 km², and more than doubling in volume. Continued differential rebound after 6000 cal yr B.P. (5.2 ¹⁴C ka B.P.) has further expanded the lake, although today it is deepening by only a few cm per century at the southern end. In addition, climate change in the Holocene probably played a role in lake level fluctuations. Based on our calculation of a modern hydrological budget for Lake of the Woods, reducing runoff and precipitation by 65% and increasing evaporation from the lake by 40% would end overflow and cause the level of the lake to fall below the outlets at Kenora. Because this climate change is comparable to that recorded during the mid-Holocene warming across the region, it is likely that the area covered by the lake at this time would have been less than that determined from differential isostatic rebound alone.     

与洪泽湖分离的淮河入海水道可行性分析

现在的洪泽湖和淮河中游河道不断淤高,致使淮河中游洪涝不断。入洪泽湖后淮河水主要流入长江。而苏北北部地区需要水,因入海泥沙数量太少而致海岸侵蚀问题不能根本解决,那里需要淮河的泥沙。为改变这种不合理的格局。在洪泽湖北岸和浅水区开挖与洪泽湖分离的河道,连接完成远期工程的淮河入海水道和拓宽、挖深的淮沭河—北六塘河—新沂河水道,使淮河水沙只经过这两条水道到达黄海,改变淮河水沙不合理的资源分配。新水道路程短,比降大,使洪泽湖和淮河中游河道不再淤高,并将进一步使淮河中游水道刷深,减轻淮河中游洪涝灾害,并为洪泽湖湖底高程降低创造条件。通过分析现在淮河的输沙量、输沙模数,与历史时期和其他流域对比,认为连云港至射阳河口这段海岸将改变为北部稳定,南部缓慢进积,形成新的淮河三角洲,彻底解决苏北海岸侵蚀问题。     

长江中上游土壤自然侵蚀量及其估算方法

首先阐述了土壤侵蚀可分为自然侵蚀和人为加速侵蚀,自然侵蚀是自地球形成以来就普遍存在的一种自然现象;继而从夷平面、河流阶地、沉积盆地等侵蚀和堆积地貌形迹论述了第四纪以来长江中上游土壤自然侵蚀存在的佐证事实;在此基础上,依据侵蚀沉积相关原理,利用沉积物的厚度、面积和沉积时段分别计算了洞庭湖流域、鄱阳湖流域和古云梦泽流域全新世以来的自然侵蚀量,它们分别为264.2t/km² · a、 312.5t/km² · a和297.0t/km² · a;同时,本文还辅以川西和三峡地区的对比实验小区资料,现代自然侵蚀量分别为342.0t/km² · a、 75~270t/km² · a佐证历史自然侵蚀量。长江上中游区域的自然侵蚀量介于264.0t/km² · a ~342.0t/km² · a之间。流域平均自然侵蚀量是现代侵蚀量的50%~60%之间;本研究成果有助于对长江中上游现代土壤侵蚀的属性、演变过程有一个科学的认识;同时可为生态保护、环境友好建设目标提供背景参照物。     

近20a察尔汗盐湖区景观格局变化与趋势分析

柴达木盆地主要景观类型为干盐湖和盐渍地,为了解区内各类景观类型空间分布特征、景观类型变化转移矩阵及变化趋势,分别选取了2000年、2010年、2020年作为3个关键研究时段,以Landsat TM多光谱卫星遥感数据为数据源,采用水体指数法与目视解译相结合的方法,建立了七类遥感图像解译标志,对近20a察尔汗盐湖区景观格局变化进行了分析。结果表明:察尔汗湖区的工矿用地面积、盐田面积、人工湿地(水库)面积在2000~2020年呈现出明显增加的趋势,而盐湖和干盐湖的面积呈现出明显减少的趋势;2000年以后,人工湿地(水库)的面积逐年增长达到了218.88 km²,在以盐滩戈壁为主的原生环境比较恶劣的盐湖区内,这片新生水域为当地野生动植物提供了十分宝贵的生境场所。     

Water resources of the Lakes of Russia

Presented are the results from qualitatively assessing the water resources of the lakes of the RF for all of the federal districts and the constituent entities of the Russian Federation involved in them. The assessment was made in the Institute of Limnology, Russian Academy of Sciences, following an ingenious technique that implies using real-time satellite-acquired data and the capabilities of the Google Earth program. Within the RF, interpretation covered the water bodies of different origins (either natural or artificial), including the lakes with a surface area of more than 0.01 km². As a result, data were obtained for the volume of water resources contained in the water bodies of the RF, having a natural origin. It was found that, in spite of the huge lake resources, their distribution across the country’s territory is extremely uneven and is weakly correlated with the main centers of population and economic development. The most well-developed territories of the RF often experience a shortage of water resources, whereas the poorly developed regions are endowed with an immense potential of lake waters. Anthropogenic pressure leads to an even larger unevenness of lake water resource distribution. A comparison of the present-day lake areas as obtained from satellite images for the 2000s with cadastre assessment data for the 1960s has shown some decrease in the lake water resources for the European part of the country. A decrease in the surface area of the lakes and a drying of a number of natural water bodies were revealed for the economically most welldeveloped regions, both in the south of the Russian Plain and in a number of its central regions. On the other hand, the lake water resources of the RF were increased by creating man-made water bodies to contain about 890 km³ of water.     

青海可可西里东北部多秀湖和盐湖水化学特征研究

2016年3月系统采集了青海可可西里东北部多秀湖和盐湖的湖水及其入湖冰川融水。研究发现,两个湖泊湖水中离子含量均较高,主要阳离子含量顺序均为Na~+Mg~(2+)K~+Ca~(2+),主要阴离子含量顺序均为Cl~-SO_4~(2-)HCO_3~-CO_3~(2-);而入湖冰川融水的离子含量非常低。根据库尔纳可夫—瓦良什科水化学分类标准,多秀湖湖水属于硫酸盐型—硫酸镁亚型,盐湖湖水属于硫酸盐型—硫酸钠亚型。多秀湖和盐湖湖水Li—Mg—B的相关性均为正相关,说明两个湖泊中这3种元素的物质来源、搬运条件及富集环境具有很强的相似性。由于气候变暖导致大量矿化度低的冰川融水注入盐湖,矿化度较低的卓乃湖和库赛湖决堤湖水泄入盐湖,使得盐湖的面积较1997年扩大了5倍,湖水的矿化度降低了约10倍,而多秀湖近些年湖水矿化度变化较小。多秀湖湖水矿化度以及Li~+、Mg~(2+)和B_2O_3含量均较高,具有较好的资源潜在利用价值。     

Spatial-temporal variations of lake ice phenology in the Hoh Xil region from 2000 to 2011

Lake ice phenology, i.e. the timing of freeze-up and break-up and the duration of the ice cover, is regarded as an important indicator of changes in regional climate. Based on the boundary data of lakes, some moderate-high resolution remote sensing datasets including MODIS and Landsat TM/ETM+ images and the meteorological data, the spatial-temporal variations of lake ice phenology in the Hoh Xil region during the period 2000–2011 were analyzed by using RS and GIS technology. And the factors affecting the lake ice phenology were also identified. Some conclusions can be drawn as follows. (1) The time of freeze-up start (FUS) and freeze-up end (FUE) of lake ice appeared in the late October–early November, mid-November–early December, respectively. The duration of lake ice freeze-up was about half a month. The time of break-up start (BUS) and break-up end (BUE) of lake ice were relatively dispersed, and appeared in the early February–early June, early May–early June, respectively. The average ice duration (ID) and the complete ice duration (CID) of lakes were 196 days and 181 days, respectively. (2) The phenology of lake ice in the Hoh Xil region changed dramatically in the last 10 years. Specifically, the FUS and FUE time of lake ice showed an increasingly delaying trend. In contrast, the BUS and BUE time of lake ice presented an advance. This led to the reduction of the ID and CID of lake. The average rates of ID and CID were–2.21 d/a and–1.91 d/a, respectively. (3) The variations of phenology and evolution of lake ice were a result of local and climatic factors. The temperature, lake area, salinity and shape of the shoreline were the main factors affecting the phenology of lake ice. However, the other factors such as the thermal capacity and the geological structure of lake should not be ignored as well. (4) The spatial process of lake ice freeze-up was contrary to its break-up process. The type of lake ice extending from one side of lakeshore to the opposite side was the most in the Hoh Xil region.     

Late Pleistocene and Holocene lake fluctuations in the Sevier Lake basin,Utah, USA

Sevier Lake is the modern lake in the topographically closed Sevier Lake basin, and is fed primarily by the Sevier River. During the last 12 000 years, the Beaver River also was a major tributary to the lake. Lake Bonneville occupied the Sevier Desert until late in its regressive phase when it dropped to the Old River Bed threshold, which is the low point on the drainage divide between the Sevier Lake basin and the Great Salt Lake basin. Lake Gunnison, a shallow freshwater lake at 1390 m in the Sevier Desert, overflowed continuously from about 12 000 to 10 000 yr B.P., into the saline lake in the Great Salt Lake basin, which continued to contract. This contrast in hydrologic histories between the two basins may have been caused by a northward shift of monsoon circulation into the Sevier Lake basin, but not as far north as the Great Salt Lake basin. Increased summer precipitation and cloudiness could have kept the Sevier Lake basin relatively wet.By shortly after 10 000 yr B.P. Lake Gunnison had stopped overflowing and the Sevier and Beaver Rivers had begun depositing fine-grained alluvium across the lake bed. Sevier Lake remained at an altitude below 1381 m during the early and middle Holocene. Between 3000 and 2000 yr B.P. the lake expanded slightly to an altitude of about 1382.3 m. A second expansion, probably in the last 500 years, culminated at about 1379.8 m. In the mid 1800s the lake had a surface altitude of 1379.5 m. Sevier Lake was essentially dry (1376 m) from 1880 until 1982. In 1984–1985 the lake expanded to a 20th-century high of 1378.9 m in response to abnormally high snow-melt runoff in the Sevier River. The late Holocene high stands of Sevier Lake were most likely related to increased precipitation derived from westerly air masses.This is the first of a series of papers to be published by this journal that was presented in the paleolimnology sessions organized by R. B. Davis and H. Löffler for the XIIth Congress of the International Union for Quaternary Research (INQUA), which took place in Ottawa, Canada in August 1987. Drs. Davis and Löffler are serving as guest editors of this series.     

博斯腾湖的水环境保护与可持续利用对策

本文通过实地调查和对1999～2001年的监测资料的分析,从水环境污染物特性、水环境质量变化、排污源分布及排污量计算等方面探讨了博斯腾湖水环境问题及其成因。提出建立博斯腾湖保护区,加大管理检查和执法力度,加强对农田排污水的控制,强化重点排污口和重点城镇生活污水的排污管理,并通过湖滨湿地生态恢复工程、增源节水工程、加速湖水循环工程等措施,保护和改善博斯腾湖水环境     

鄱阳湖水文特征动态变化遥感监测

鄱阳湖是中国第一大淡水湖,对鄱阳湖的水文变化进行持续监测可以为流域内生态环境变化提供基础数据,有利于研究其与长江和流域内河流的交互关系,更好地服务于陆面过程模式和水资源管理。本文利用卫星测高数据反演的鄱阳湖水位数据与MODIS数据结合,对鄱阳湖2000—2015年的水位、水域面积和水量变化进行研究,并通过水量平衡模型,推导出了同期长江—鄱阳湖的水量交互。研究发现,2000—2015年鄱阳湖面积呈现波动性变化,最大水域面积为3600 km ²,是最小水域面积482 km ²的7.5倍。2004年、2007年、2009年和2011年水域面积比较低,2012年后形势好转。每年1月、2月、12月份是鄱阳湖干季,水域面积低至500 km ²,湖口处水位可低至4.71 m,湖面从南往北倾斜,南北水位差异达2.59 m。相对于2000—2015年最低水量,干季时湖泊水量平均增加量为3 km ³。每年6—9月份是鄱阳湖的湿季,水域面积一般大于2670 km ²,水位高于15 m,南北水位差异不大,相对于2000—2015年最低水量,湿季时湖泊水量平均增加量为12 km ³。2000—2015年鄱阳湖流入长江的水量范围为-7~40.66 km ³,每年有93.33%的时间水流从鄱阳湖流入长江。流入长江的水量多少具有明显的季节性,通常5月、6月流入长江的水量高于7月、8月,主要因为7月、8月长江中上游降水增加,长江干流来水增多,对鄱阳湖湖水倒灌有一定的顶托作用。     

洞庭湖与长江水体交换能力演变及对三峡水库运行的响应

运用洞庭湖区与长江干流相关控制站1951-2010 年实测水文数据, 在分析江湖水力关系的基础上, 从不同时间尺度分析江湖水体交换能力的演变特征及其对三峡水库运行的响应。结果表明:① 7-9 月长江荆南三口对洞庭湖的补给能力较强, 1-3 月洞庭湖对长江的补给能力较强;② 江湖水体交换系数具有明显的年代际波动, 其中1951-1958 年、1959-1968 年荆南三口对湖泊的补给能力较强, 而2003-2010 年湖泊对长江的补给能力增强;③ 三峡水库运行后无论是典型年还是在水库不同调度方式运行期, 三口分泄能力减弱, 入湖水量减少, 而因四水入湖水量占绝对优势, 湖泊对长江的补给能力明显增强;④ 尽管影响江湖水体交换能力的因素极为复杂, 但从总体上讲, 除受流域降水波动影响外, 江湖水体交换能力在不同时间尺度上的演变特征及其过程均随着江湖水体交换量的变化而变化, 说明江湖水体交换能力强度与江湖水体交换量之间存在着彼此消长的关系。     

Non-climatic growth of the saline Lake Beseka,Main Ethiopian Rift

When using rift lakes as proxies for palaeoclimate it is essential to know if water level changes are of geological or climatic origin, and whether a reinterpretation of palaeo-lake levels derived from lithostratigraphic sequences is required. The saline, endorheic Lake Beseka is located in the tectonically active Main Ethiopian Rift. Despite the aridity of the rift valley the lake's surface area quadrupled from 11.1 km² in 1973 to 39.5 km² in 2002. We quantify the lake growth by means of a detailed bathymetric model and high-resolution satellite time series. We analyse the potential climatic, anthropogenic, and tectonic agents of Lake Beseka's growth. Multitemporal remote sensing data and meteorological records were compared with in-situ measurements of hydrochemical parameters and water depth to address the reason for the lake level rise. Our results suggest that Lake Beseka's expansion originates from an increased discharge of the hot springs. The combined analysis of satellite data and in-situ measurements proved to be a valid tool for the quantification of lake level changes and can help to detect the causes of these variations.     

Great Lakes response to catastrophic inflows from Lake Agassiz: some simulations of a hydraulic geometry for chained lake systems

Simulations (216) were undertaken to evaluate the impact of typical Lake Agassiz outbursts on the upper Great Lakes under plausible variations in lake surface areas and sill widths. Flows over sills out of lakes are modelled using the equation for a broad-crested weir, with the model time increment set to one day. The model was evaluated for Lake Agassiz outlet sill widths of 1, 4, and 10 km and with outbursts ranging from 100 000 m³ s^–1 to 600 000 m³ s^–1. The surface area of Lake Agassiz was evaluated for 182 000 km² ±20%. The surface area of the upper Great Lakes were modelled as either Lake Algonquin (Superior, Huron and Michigan basins =200 000 km²) or Lake Minong (Superior basin 87 000 km²) with sill widths of 0.5, 1.5, and 3 km.Downstream peak discharge modelled at the outlet sill of the upper Great Lakes, was normally between 20 and 60% of the initial outburst, with a lagtime to peak usually between 80 and 280 days. Upper Great Lakes water level rises of between 2 and 20 m are calculated with rises to 36 m for some configurations. Rise magnitude is inversely related to the width of the outlet sills at both lake systems and to the surface area of the receiving lake.The modeling implies that measuring outflow from the upper Great Lakes, or water level rises, does not in itself determine peak or total outflow from Lake Agassiz unless the dimensions of the Lake Agassiz and upper Great Lakes outflow sills are also known.Lake level rises probably coincided on the upper Great Lakes with meltout from the winter freeze-up. Lake levels re-attain equilibrium values with respect to through flow within three years of an outburst. Substantial episodic lake level rises in the upper Great Lakes may have had severe impacts on the lake biota, for example via the affect on spawning grounds.     

Applying energy theory to understand the relationship between the Yangtze River and Poyang Lake

The complex relationship between the Yangtze River and Poyang Lake controls the exchange of water and sediment between the two, and exerts effects on water resources, flooding, shipping, and the ecological environment. The theory of energy is applied in this paper to investigate the physical mechanisms that determine the nature of the contact between the Yangtze River and Poyang Lake and to establish an energy difference (F_e) index to quantify the interactions between the two systems. Data show that F_e values for this interaction have increased since the 1950s, indicating a weakening in the river effect while the lake effect has been enhanced. Enclosure of the Three Gorges Reservoir (TGR) has also significantly influenced the relationship between the river and the lake by further reducing the impacts of the Yangtze River. The river effect also increases slightly during the dry season, and decreases significantly at the end of the flooding period, while interactions between the two to some extent influence the development of droughts and floods within the lake area. Data show that when the flow of the five rivers within this area is significant and a blocking effect due to the Yangtze River is also clearly apparent, floods occur easily; in contrast, when the opposite is true and the flow of the five rivers is small, and the Yangtze River can accommodate the flow, droughts occur frequently. Construction and enclosure of the TGR also means that the lake area is prone to droughts during September and October.     

近10年来可可西里地区主要湖泊冰情时空变化

基于2000-2011年可可西里地区湖泊边界矢量数据、MODIS和Landsat TM/ETM+遥感影像和气象数据等资料,利用RS和GIS技术综合分析该地区主要湖泊冰情变化特征及其影响因素。结果表明：① 可可西里地区湖泊开始结冰和完全结冰出现在每年的10月下旬至11月上旬和11月中旬至12月上旬,湖泊由开始冻结至完全冻结持续时间约半个月;湖冰开始消融和完全消融时间较为分散,主要出现在每年的4月下旬至6月初和5月初至6月上旬,湖泊完全封冻期和封冻期为181 d和196 d。② 2000-2011年间,可可西里地区湖冰物候特征发生了显著变化,湖泊开始冻结和完全冻结时间推迟,湖冰开始消融和完全消融时间提前,湖泊完全封冻期和封冻期持续时间普遍缩短,平均变化速率分别为-2.21 d/a和-1.91 d/a。③ 湖冰物候特征及湖泊冰情演变是区域气候变化和湖泊自身条件共同作用的结果,其中气温、湖泊面积、湖水矿化度和湖泊形态是影响湖冰物候特征的主要因素,而湖泊热储量、地质构造等因素对湖冰演化的作用亦不可忽视。④ 可可西里地区湖泊冻结空间模式与消融过程相反,以湖冰由湖泊一岸扩展到另一岸的湖泊数量居多。     

Analysis of deposition and erosion of Dongting Lake by GIS

The Dongting Lake is located in the south beach of the middle reaches of the Yangtze River. Its catchment, with an area of 262,823 km2 or about 12% of the total Yangtze River catchment, is situated between 28o43?29o32扤 and 112o54?113o8扙, and crosses Hubei and Hunan provinces in administrative division. The main tributaries include Xiangjiang, Zishui, Yuanjiang, Lishui rivers (4 Tributaries) and some local rivers, such as Miluo River, Xinqiang River and other little streams. In the nor…