Snake River: A Navigation and Spawning Dilemma

The Snake River in northwestern United States is 1735 km long, the largest tributary of the Columbia River and is the 13th longest river in the United States. The Snake River drainage basin includes parts of six U.S. states. The Snake River Plain was created by a volcanic hotspot that lies beneath Yellow-stone National Park. The previous Ice Age carved out canyons, cliffs and waterfalls along the middle and lower Snake River. The Missoula Flood was to the north and Bonneville Flood to the south altered the Snake River and surrounding landscape. The Snake River has a drainage basin of 282,000 km2 in the states of Oregon, Washington, Utah, Nevada and Idaho. The Snake River drops from mountain elevations of 3000 m to its confluence with the Columbia River. The river is one of the most biologically diverse freshwater systems in the United States with trails designed to promote recreational tourism, increase use of the Snake River and create generations of people who care about the river and are willing to protect and provide environmental stewardship of the river watershed resources.

Yellowstone Region Drainage History as Determined from the 1955 Ashton, Idaho, Montana, and Wyoming 1:250,000 Scale Topographic Map, USA

The United States Geological Survey (USGS) 1955 (revised in 1972) Ashton topographic map (Ashton map) with a 1:250,000 scale and a 200-foot (about 60-meter) contour interval covers almost all of Yellowstone National Park and some adjacent regions to the south and west. In spite of numerous publications discussing Yellowstone region geologic history the drainage system and erosional landform evidence on the Ashton map appears to have been ignored. Drainage divides identifiable on the Ashton map separate the north-oriented Yellowstone, Gallatin, Madison, and Jefferson River drainage basins (which are located to the north and east of the continental divide with their water flowing to the Missouri River and ultimately the Gulf of Mexico) from the south-oriented Snake River drainage basin (with its water eventually reaching the Pacific Ocean). The Ashton map shows water-eroded passes and through valleys which link diverging and converging valleys which drain in opposite directions from the continental divide. These diverging and converging valleys suggest large volumes of south-oriented water once flowed across the Yellowstone region continental divide and some other Ashton map drainage divides. The accepted geology and glacial history paradigm (accepted paradigm) cannot satisfactorily explain the Ashton map drainage system and erosional landform evidence, which may be why geomorphologists have never addressed the map evidence. A new and fundamentally different geology and glacial history paradigm requiring the Yellowstone region to be located on the rim of a continental ice sheet created and occupied deep “hole” (which was uplifted as immense meltwater floods flowed across it) explains Ashton map drainage system and erosional landform evidence, but raises questions about previously published Yellowstone region geologic histories.

基于Snake模型的地图中河流提取算法

地图的手工矢量化是一项耗时、费力的工作。该文根据彩色地图中河流的特点,提出利用改进的Snake模型提取地图中的河流。通过对地图中河流线的结构特征进行统计分析,寻找河流线基元;利用改进主动轮廓模型的自动跟踪功能,实现河流的最终提取。实验结果验证了本算法的有效性。

复杂水体边界提取的改进正交T-Snake模型

引入拓扑自适应动态轮廓(T-Snake)模型并进行了改进,设计了合适的能量函数,提出了目标内部岛状空洞引起的拓扑冲突的检测与处理机制,实现了包含河中岛的复杂河流边界的精确提取。针对模型初始轮廓需手动构造的缺点,利用影像分形维数最小值获取水体内部区域并实现轮廓自动初始化。试验表明,该方法可有效提取水体深凹边界和含河中岛的河流边界,在精度和效率上优于传统Snake和GVF Snake模型。

Origin of Mountain Passes across Continental Divide Segments Surrounding the Southwest Montana Big Hole and Beaverhead River Drainage Basins, USA

The evolution of southwest Montana’s Big Hole and Beaverhead River drainage basins is determined from topographic map evidence related to mountain passes crossing what are today high altitude drainage divides including North America’s east-west Continental Divide. Map evidence, such as orientations of valleys leading away from mountain passes (and saddles) and barbed tributaries found along the downstream drainage routes, is used to reconstruct flow directions of streams and rivers that once crossed the present-day high mountain divides. Large south-oriented anastomosing complexes of diverging and converging channels are interpreted to have eroded what are today closely spaced passes and saddles now notched into high mountain ridges. Water in those south-oriented channels is interpreted to have flowed across emerging mountains and subsiding basins. Headward erosion of deeper southeast-oriented valleys, assisted by crustal warping, concentrated south-oriented water in fewer and deeper valleys as the water flowed from southwest Montana into what are today Idaho and the Snake River drainage basin. Headward erosion of the Big Hole River valley between the emerging Anaconda and Pioneer Mountains, also assisted by crustal warping, reversed all Big Hole Basin drainage so as to create the north-, east-, and south-oriented Big Hole River drainage route. A final and even more major reversal of flow in the present-day north-oriented Montana Missouri River valley, with the assistance of additional crustal warping, next ended all remaining flow to Idaho and the Snake River drainage basin and reversed and captured all drainage in the present-day north-oriented Big Hole, Beaverhead, and Red Rock River drainage basins. The observed map evidence indicates that prior to the final flow reversal events, large volumes of south-oriented water flowed across southwest Montana’s Big Hole and Beaverhead River drainage basins.

大禹治水与龙蛇神话

The writer thinks that the dragons here refer to the floods and rivers because floods and rivers are the ecological starting points, the natural basis for the dragons and the original basic form of dragons as well. The dragons and snakes here are not the totems in Xia Tribe when Yu regulated the rivers and watercourses.Yu was called the dragon-killer or snake-killer.So Yu killed dragon-like Gonggong and Xiangyao. Tales such as "The Yellow Dragon’s Hailing of Tail" tell us the connections between dragons and snakes and thefloods and rivers.

北汉庄油田三垛组一段储层沉积微相研究及其应用

本文结合研究区有限的取芯资料,通过砂体的沉积特征、测井相特征及砂体的空间分布对北汉庄油田三垛组一段进行了系统的沉积微相研究。结果表明,三垛组一段为河流相沉积,主要发育边滩、决口扇、泛滥平原、心滩、河道间5个微相。在此基础之上,通过单井剖面和井间剖面对比分析,研究沉积微相在垂向上和平面上的变化规律,并综合砂体厚度展布特征和地层厚度特征,编制了研究区内不同砂层组沉积时期沉积微相平面展布图。结果表明,三垛组一段底部辫状河河道沉积微相沉积的VIII砂体在研究区是最好的储层。这种对储层的详细解释以及对其沉积微相的精细描述有助于优质储层的鉴别和分布预测。

428XL蛇形排列在江苏水网地区高精度三维勘探中的运用

江苏油田某高精度三维工区河流纵横,且部分为通航的主干河流,若在河流上大量架设能让船只通行的排列无疑将增加施工难度,不利于效率的提升。面对这种难题,仪器技术人员结合428XL仪器灵活的越障能力,通过使用蛇形排列,极大地减少了排列线过河次数,使通航河流对施工的影响降到最低,取得了好的效果。文章详细介绍了蛇形排列的使用方法及技巧。

改进Balloon Snake算法提取遥感影像水体边界

相比于正交T-Snake算法,传统Balloon Snake算法不受格网约束,能够更加精确提取高分辨率遥感影像上水体,然而尚不能解决河中岛引起的拓扑冲突问题。由此,本文提出了一种改进Balloon Snake算法(T-Balloon Snake),设计了目标内部由于空洞引起的拓扑冲突检测与处理机制。算法首先在目标水体内部手动设置一个初始轮廓,在曲线每次膨胀前对曲线进行自相交检测,若存在拓扑冲突则对曲线进行分裂与合并处理,最终直至迭代停止。实验选取了三类湖泊与河流高分影像,实现了复杂遥感影像水体矢量边界的一次性精确提取。实验结果表明,该方法可直接有效提取水体中深凹以及岛状边界,在提取结果正确性和完整性上都优于传统Balloon Snake算法。

蛇尾河太平镇河段治理设计洪水计算分析

太平镇河段治理工程设计洪水计算分析为蛇尾河防洪标准的提升提供了基本依据,对蛇尾河道治理工程建设具有十分重要的工程意义。为此,文章以西峡县蛇尾河太平镇鱼库村至太平村段河道治理工程设计洪水计算分析为典型案例展开分析研究。结果表明,在全面熟悉蛇尾河流域概况的基础上,选择与治理河段内洪水特性有密切关系,距离最近的老灌河米坪水文站作为参照站,利用此站实测1956—2011年共计56年的洪水资料系列,进行了设计暴雨分析,并应用推理公式法和面积比拟法完成了蛇尾河流域设计洪水计算(包括施工期设计洪水),最终以设计雨洪法的洪峰流量计算成果为参考,以水文比拟法计算成果为设计基准。可为类似蛇尾河治理工程设计洪水计算分析实践提供借鉴参考。