Evolution of Mesozoic Volcanic Basins and Red Basins in the Gan-Hang Tectonic-Volcanic Metallogenic Belt

This paper mainly proposes six major regional geological events in the active continental-margin mantle uplift zone and discusses the oscillation nature of the evolution of Mesozoic volcanic basins and red basins, origin of erosion in the late stage of red basins and mechanism of volcanism.

Spatial and temporal variation of runoff of Red River Basin in Yunnan

This paper studies the variation of runoff of Red River Basin and discusses the influence of＂corridor-barrier＂functions of valleys and mountains on variation of runoff by using GIS and statistic methods based on the monthly precipitation,temperature and evaporation data from 1960 to 2000 at 32 meteorological stations in Red River Basin,and the annual runoff data of Yuanjiang River,Lixian River and Panlong River from 1956 to 2000.The results show out：（1）Under the effect of＂corridor-barrier＂functions of valleys and mountains in Red River Basin,the patterns of annual precipitation and runoff depth distribution in spatial change a NW-SE direction,which is similar with the trend of the Red River valley and Ailao mountains.（2）In the long temporal scale averaged over years,the most obvious effects of the＂corridor-barrier＂functions is on runoff variation,and the second is on the precipitation, but not obvious on the temperature.（3）Under the superposed effect of climate changes and the＂corridor-barrier＂functions of valleys and mountains in Red River Basin,the difference of runoff variation is obvious in the east-west direction：the runoff variation of Yuanjiang River along the Red River Fault present an ascending trend,but the Lixian River on the west side of the Fault and the Panlong River on the east present a descending trend;the annual runoff in Yuanjiang River and Panlong River had a quasi-5a periods,and Panlong River had a quasi-8a periods;the runoff variation are quite inconsistent in different periods among the three river basins.

Torrent risk zonation in the Upstream Red River Basin based on GIS

This paper explores the methodology for compiling the torrent hazard and risk zonation map by means of GIS technique for the Red River Basin in Yunnan province of China, where is prone to torrent. Based on a 1：250,000 scale digital map, six factors including slope angle, rainstorm days, buffer of river channels, maximum runoff discharge of standard area, debris flow distribution density and flood disaster history were analyzed and superimposed to create the torrent risk evaluation map. Population density, farmland percentage, house property, and GDP as indexes accounting for torrent hazards were analyzed in terms of vulnerability mapping. Torrent risk zonation by means of GIS was overlaid on the two data layers of hazard and vulnerability. Then each grid unit with a resolution of 500 m- 500 m was divided into four categories of the risk： extremely high, high, moderate and low. Finally the same level risk was combined into a confirmed zone, which represents torrent risk of the study area. The risk evaluation result in the upper Red River Basin shows that the extremely high risk area of 13,150 km^2 takes up 17.9% of the total inundated area, the high risk area of 33,783 km^2 is 45.9%, the moderate risk area of 18,563 km^2 is 25.2% and the low risk area of 8115 km^2 is 11.0%.

Ecological Security Assessment of Red River Basin in Guangxi

[Objective] The study aimed at assessing the ecological security of Red River basin in Guangxi. [Method] Firstly, the ecological security assessment index system of Red River basin was established based on the framework of 'pressure-state-response' model, and index information of ecological security assessment was extracted by using RS and GIS technology; afterwards, the ecological security of Red River basin was divided into five grades according to ecological security index, and the distribution and characteristics of ecological security at various levels were analyzed; finally, the measures to maintain the ecological security of Red River basin were put forward on the basis of problems in ecological security. [Result] Most areas of Red River basin in Guangxi were in generally safe state, especially Lingyun County, Fengshan County, Du'an County, Dahua County, Shanglin County, Binyang County, Guiping City, etc., and the area accounted for 74.25% of total area; next came safer state (12.74%), the regions in the two states above were the most important environmental areas of Red River basin. The ecological security problems of Red River basin were mainly related to fragile ecological environment, lagging economic development, rapid population growth, excessive development and utilization of natural resources and so forth. [Conclusion] The research could provide scientific references for the rational development and utilization of land resources, protection and construction of ecological environment in Red River basin.

Artificial Intelligence Technique in Hydrological Forecasts Supporting for Water Resources Management of a Large River Basin in Vietnam

Hydrological forecasting plays an important role in water resource management, supporting socio-economic development and managing water-related risks in river basins. There are many flow forecasting techniques that have been developed several centuries ago, ranging from physical models, physics-based models, conceptual models, and data-driven models. Recently, Artificial Intelligence (AI) has become an advanced technique applied as an effective data-driven model in hydrological forecasting. The main advantage of these models is that they give results with compatible accuracy, and require short computation time, thus increasing forecasting time and reducing human and financial effort. This study evaluates the applicability of machine learning and deep learning in Hanoi water level forecasting where it is controlled for flood management and water supply in the Red River Delta, Vietnam. Accordingly, SANN (machine learning algorithm) and LSTM (deep learning algorithm) were tested and compared with a Physics-Based Model (PBM) for the Red River Delta. The results show that SANN and LSTM give high accuracy. The R-squared coefficient is greater than 0.8, the mean squared error (MSE) is less than 20 cm, the correlation coefficient of the forecast hydrology is greater than 0.9 and the level of assurance of the forecast plan ranges from 80% to 90% in both cases. In addition, the calculation time is much reduced compared to the requirement of PBM, which is its limitation in hydrological forecasting for large river basins such as the Red River in Vietnam. Therefore, SANN and LSTM are expected to help increase lead time, thereby supporting water resource management for sustainable development and management of water-related risks in the Red River Delta.

Submarine slide evidence for late Miocene strike-slip reversal of the Red River Fault

During the late Miocene(~5.5 Ma), a large-scale submarine slide with an area of approximately 18000 km^2 and a maximum thickness of 930 m formed in the deep-water region of the Qiongdongnan Basin. The large-scale submarine slide has obvious features in seismic profile, with normal faults in the proximal region, escarpments at the lateral boundary, and a pronounced shear surface at the base. The internal seismic reflections are chaotic and enclosed by parallel and sub-parallel seismic events.The main direction of sediment transport was from south to north and the main sediment source was the southern region of the Qiongdongnan Basin, which is located in the east of the Indo-China Peninsula and the north of the Guangle uplift. In this region,late Miocene strike-slip reversal of the Red River Fault, uplift and increased erosion of the Indo-China Peninsula, and an abrupt rise in the rate of deposition in the western part of the South China Sea provided the basic conditions and triggering mechanism for the large-scale submarine slide. The discovery of the large-scale submarine slide provides sedimentological evidence for the tectonic event of late Miocene strike-slip reversal of the Red River Fault. It can also be inferred that the greatest tectonic activity during the process of the Red River Fault reversal occurred at ~5.5 Ma from the age of top surface of the submarine slide.

Development of an integrated modeling system for improved multi-objective reservoir operation

Reservoir is an efficient way for flood control and improving all sectors related to water resources in the integrated water resources management.Moreover,multiobjective reservoir plays a significant role in the development of a country’s economy especially in developing countries.All multi-objective reservoirs have conflicts and disputes in flood control and water use,which makes the operator a great challenge in the decision of reservoir operation.For improved multi-objective reservoir operation,an integrated modeling system has been developed by incorporating a global optimization system(SCE-UA)into a distributed biosphere hydrological model(WEB-DHM)coupled with the reservoir routing module.The new integrated modeling system has been tested in the Da River subbasin of the Red River and showed the capability of reproducing observed reservoir inflows and optimizing the multi-objective reservoir operation.First,the WEB-DHM was calibrated for the inflows to the Hoa Binh Reservoir in the Da River.Second,the WEB-DHM coupled with the reservoir routing module was tested by simulating the reservoir water level,when using the observed dam outflows as the reservoir release.Third,the new integrated modeling system was evaluated by optimizing the operation rule of the Hoa Binh Reservoir from 1 June to 28 July 2006,which covered the annual largest flood peak.By using the optimal rule for the reservoir operation,the annual largest flood peak at downstream control point(Ben Ngoc station)was successfully reduced(by about 2.4 m for water level and 2500 m^(3)·s^(-1) for discharge);while after the simulation periods,the reservoir water level was increased by about 20 m that could supply future water use.