Nowhere to Call Home: A Study of Sanmenxia-Reservoir Resettlement From Henan To Gansu, 1956–1965

In the late 1950s, the creation of a large reservoir for the Sanmenxia hydropower project required the displacement of tens of thousands of households along the Yellow River. Simultaneously, the state commenced a land-reclamation project, sending people from populated areas to the frontiers. Under the supervision of county and provincial authorities, more than 7,000 reservoir inhabitants from Henan were mobilized to migrate to Dunhuang, an oasis surrounded by the Gobi Desert in the northwest. The socialist state's pursuit of irrigation and hydroelectricity benefits not only altered the waterscape of the Yellow River; it also impacted nearby rural communities as well as those a thousand miles away. From the high-modernist perspective, the state-sponsored demographic engineering and the Yellow River engineering seemed to complement each other well. Yet, with the massive flight of resettlers, the state-envisioned integration of reservoir displacement and frontier reclamation ultimately failed.

Remote sensing inversion characteristic and driving factor analysis of wetland evapotranspiration in the Sanmenxia Reservoir area, China

Evapotranspiration in the hydrologic cycle realizes the energy and water transport in the atmosphere. Evapotranspiration differences concerning land-use types provide data for studying the evapotranspiration of river basins. To investigate the evapotranspiration in the reservoir under artificial regulation, we selected the river basin in the Sanmenxia Reservoir as the study area. Data sources are two-period Landsat8 OIL_TIRS remote sensing images during the growing season of wetland plants. Based on meteorological data in this river basin, we investigated the evapotranspiration differences of different land-use types using the Surface Energy Balance Algorithm for Land model. The FAO Penman–Monteith formula verified the remote sensing inversion results. Analysis shows that significant differences were manifested between wetland and non-wetland landscapes in evapotranspiration among different land-use types. Non-wetland landscapes accounted for about 97.23% of the river basin's total area, but their daily average evapotranspiration was only 7.26 mm/d. Those of wetland landscapes were 2.77% and 12.17 mm/d. In this river basin, the differences between the wetland and non-wetland landscapes in evapotranspiration are mainly associated with plant diversity, vegetation coverage and surface temperature (beyond other driving factors like meteorological and hydrological solar radiation factors).

DNA metabarcoding of zooplankton communities: species diversity and seasonal variation revealed by 18S rRNA and COI

Background Zooplankton is an important component of aquatic organisms and has important biological and economical significance in freshwater ecosystems. However, traditional methods that rely on morphology to classify zooplankton require expert taxonomic skills. Moreover, traditional classification methods are time-consuming and labor-intensive, which is not practical for the design of conservation measures and ecological management tools based on zooplankton diversity assessment. Methods We used DNA metabarcoding technology with two different markers: the nuclear small subunit ribosomal RNA (18S rRNA) and mitochondrial cytochrome c oxidase (COI), to analyze 72 zooplankton samples collected in 4 seasons and 9 locations from the Sanmenxia Reservoir. We investigated seasonal changes in the zooplankton community and their relationship with water environmental factors. Results A total of 190 species of zooplankton were found, belonging to 12 phyla, 24 classes, 61 orders, 111 families, and 174 genera. Protozoa, especially ciliates, were the most diverse taxa. Richness and relative abundance of zooplankton showed significant seasonal changes. Both alpha and beta diversity showed seasonal trends: the diversity in summer and autumn was higher than that in winter and spring. The zooplankton diversity was most similar in winter and spring. By correlating metabarcoding data and water environmental factors, we proved that water temperature, chemical oxygen demand, total nitrogen and ammoniacal nitrogen were the main environmental factors driving the seasonal changes in zooplankton in the Sanmenxia Reservoir. Water temperature, followed by total nitrogen, were the most influential factors. This study highlights the advantages and some limitations of zooplankton molecular biodiversity assessment using two molecular markers.

Service Value of Wetland Ecosystem in Sanmenxia Reservoir Area

<p>The evaluation of wetland ecosystem service lays the foundation to the wetland protection and exploitation. Evaluating the ecological service of all types of wetlands scientifically and reasonably is critical to improving the quality of ecological environment and securing the regional ecological security. In the middle reaches of the Yellow River, a typical sediment-laden river wetland- Sanmenxia Reservoir area Wetland, is chosen as the research target. Based on the systematic analysis its unique formation process and ecological services, the biological resources are formed, including the value of supply service, regulation service, support service, and cultural service. The value of wetland ecological services was calculated by market value, opportunity cost, shadow engineering and substitution cost methods. The results show that the total value of wetland ecosystem service is worth about 80.86 billion yuan, and the dominant ecological services are regulation service and support service with the economic value of 46.49% and 50.85% respectively. The evaluation results make people more directly understand the importance of wetland leading ecological service and provide scientific basis for the protection and management of wetland in Sanmenxia Reservoir area.</p>

Research on Evolutionary Game of Engineering Community Members from the Perspective of Engineering Ethics

Engineering ethics is a system of ethical principles applied to engineering, which plays the role of value guidance and criterion evaluation in engineering construction activities. Based on engineering ethics, writers review the Sanmenxia Reservoir Project, and use system dynamics to systematically study the evolutionary game of engineering community members, including government, enterprise, and people, involved in the engineering activities. The results show that the engineering community is a heterogeneous community with complex game behaviors, and the correct ethical choice is the key factor that promotes the evolution of the community members to cooperative dynamic equilibrium. Good management of ethical commitment, emphasis on professionalism and public services, strengthening risk alert and avoidance are effective ways for members of the engineering community to form a cooperative game, avoid tragedy of public resources, and ultimately ensure the orderly development of projects.

Study on Evolvement of High Beach and Deep Channel of Reservoir in the Sediment-Laden Rivers

According to datas of Sanmenxia Reservoir and physical model test of Xiaolangdi Reservoir during later sediment retaining period, the paper study evolvement of high beach and deep channel of reservoir in the sediment-laden rivers. The results show that: 1The evolution of high beach and deep channel is as follows, firstly, beach and channel increase synchronously , and then scour happens in channel. Channel scour and scour amount is crucial to form high beach and deep channel. 2It is found that tributaries were equivalent to the horizontal extension of mainstream riverbed. The deposition process of tributary is closely related to many factors of natural topographic condition, deposition morphology of mainstream at the confluence area of mainstream and tributary and so on. The cross-section of tributary kept uplift horizontally, and sand bar has formed in some tributary estuary. 3Rainfall erosion formed in flood period is beneficial to forming hyper-concentrated flow, to a certain extent; it can recover channel storage capacity, and play an important role on utilizing long-term comprehensive benefits. Studying evolvement of high beach and deep channel can supply some technical supports for regulating operational mode of Xiaolangdi Reservoir during later sediment retaining period and prolonging service life.