Impact of Forestry Interventions on Groundwater Recharge and Sediment Control in the Ganga River Basin

Water related services of natural infrastructure will help to combat the risk of water crisis, and nature-based solutions involve the management of ecosystems to mimic or optimize the natural processes for the provision and regulation of water. Forested areas provide environmental stability and supply a high proportion of the world’s accessible freshwater for domestic, agricultural, industrial and ecological needs. The present work on “Forestry Interventions for Ganga” to rejuvenate the river is one of the steps toward the Ganga River rejuvenation programme in the country. The consequences of forestry interventions for Ganga will be determined on the basis of water quantity and water quality in the Ganga River. The study conservatively estimated the water savings and sedimentation reduction of the riverscape management in the Ganga basin using the Soil Conservation Service Curve Number (SCS-CN) & GEC, 2015 and Trimble, 1999 & CWC, 2019 methodologies, respectively. Forestry plantations and soil and moisture conservation measures devised in the programme to rejuvenate the Ganga River are expected to increase water recharge and decrease sedimentation load by 231.011 MCM·yr-1 and 1119.6 cubic m·yr-1 or 395.20 tons·yr-1, respectively, in delineated riverscape area of 83,946 km2 in Ganga basin due to these interventions. The role of trees and forests in improving hydrologic cycles, soil infiltration and ground water recharge in Ganga basin seems to be the reason for this change. Forest plantations and other bioengineering techniques can help to keep rivers perennial, increase precipitation, prevent soil erosion and mitigate floods, drought & climate change. The bioengineering techniques could be a feasible tool to enhance rivers’ self-purification as well as to make river perennial. The results will give momentum to the National Mission of Clean Ganga (NMCG) and its Namami Gange programme including other important rivers in the country and provide inputs in understanding the linkages among forest structure, function, and streamflow.

Forestry Interventions and Groundwater Recharge, Sediment Control and Carbon Sequestration in the Krishna River Basin

It is a known fact that human activities have a significant impact on global rivers, making the task of rehabilitating them to their former natural state or a more semi-natural state quite challenging. The ongoing initiative called “Rejuvenation of Krishna River through Forestry Interventions” aims to contribute to the overall river rejuvenation program in the country. In this context, the effects of forestry interventions on the Krishna River will be evaluated based on water quantity, water quality, and the potential for carbon sequestration through plantation efforts. To assess the outcomes of this study, various methodologies such as Soil Conservation Service Curve Number (SCS-CN), Central Ground Water Board (CGWB) and Intergovernmental Panel on Climate Change (IPCC) have been utilized to estimate water savings, reduction in sedimentation, and carbon sequestration potential within the Krishna basin. The projected results indicate that the implementation of forestry plantations and soil and moisture conservation measures in the Krishna River rejuvenation program could lead to significant improvements. Specifically, the interventions are expected to enhance water recharge by 400.49 million cubic meters per year, reduce sedimentation load by 869.22 cubic meters per year, and increase carbon sequestration by 3.91 lakh metric tonnes per year or 14.34 lakh metric tonnes of CO2 equivalent. By incorporating forestry interventions into the Krishna riverscape, it is anticipated that the quality and quantity of water flowing through the river will be positively impacted. These interventions will enhance water infiltration, mitigate soil erosion, and contribute to an improved vegetation cover, thereby conserving biodiversity. Moreover, they offer additional intangible benefits such as addressing climate change concerns through enhanced carbon sequestration potential along the entire stretch of riverine areas.

基于MIKE HYDRO River模型的轨交交通施工期防汛安全影响论证

轨交交通施工期间,受车站结构设计、周边场地限制等因素影响,河道需要断流施工,断流会对区域的防洪除涝安全及水环境产生影响。本文以上海轨道交通13号线西延伸工程为例,构建一维河网水动力模型,分析排涝及引调水工况下水位及水质变化情况。结果表明,平原河网地区个别河道断流对于区域防洪除涝安全影响较小,会严重影响河道断流处的水环境;通过增设导流措施可以减轻断流的影响,为平原河网地区河道断流影响分析及措施制定提供依据。

Changes in sediment discharge in a sediment-rich region of the Yellow River from 1955 to 2010: implications for further soil erosion control

The well-documented decrease in the discharge of sediment into the Yellow River has attracted considerable attention in recent years. The present study analyzed the spatial and temporal variation of sediment yield based on data from 46 hydrological stations in the sediment-rich region of the Yellow River from 1955 to 2010. The results showed that since 1970 sediment yield in the region has clearly decreased at different rates in the 45 sub-areas controlled by hydrological stations. The decrease in sediment yield was closely related to the intensity and extent of soil erosion control measures and rainstorms that occurred in different periods and sub-areas. The average sediment delivery modulus（SDM） in the study area decreased from 7,767.4 t/（km^2·a） in 1951–1969 to 980.5 t/（km^2·a） in 2000–2010. Our study suggested that 65.5% of the study area with the SDM below 1,000 t/（km^2·a） is still necessary to control soil deterioration caused by erosion, and soil erosion control measures should be further strengthened in the areas with the SDM above 1,000 t/（km^2·a）.

Is Precipitation the Dominant Controlling Factor of High Inorganic Nitrogen Content in the Changjiang River and Its Mouth?

The main reasons for the high content of inorganic N and its increase by several times in the Changjiang River and its mouth during the last 40 years were analysed in this work. The inorganic N in precipitation in the Changjiang River catchment mainly comes from gaseous loss of fertilizer N, N resulting from the increases of population and livestock, and from high temperature combustions of fossil fuels. N from precipitation is the first N source in the Changjiang River water and the only direct cause of high content of inorganic N in the Changjiang River and its mouth. The lost N in gaseous form and from agriculture non point sources fertilizer comprised about 60% of annual consumption of fertilizer N in the Changjiang River catchment and were key factors controlling the high content of inorganic N in the Changjiang River mouth. The fate of the N in precipitation and other N sources in the Changjiang River catchment are also discussed in this paper.

New Challenges and Opportunities for Flood Control in the Huai River: Addressing a Changing River-Lake Relationship

This paper addresses the change of the river-lake relationship in the Huai River and its causes due to environmental change and human activities. A preliminary analysis is made from three aspects: (1) the natural geographical change particularly captured by the Yellow River, (2) water conservancy project construction, and (3) socioeconomic development in the Huai River Basin. Key problems of changes in this river-lake relationship and the Huai River flood control are tackled, involving flood control and disaster alleviation ability of the Basin, engineering and non-engineering measurements applied to flood control and disaster mitigation, and water governance for adaptive management. Research shows that the Huai River is a rather complex one due to its complex geography with a hybrid wet and dry climate zoon, and higher population density. With the alternation of the river-lake relationship and socioeconomic development in the region, new problems keep arising, imposing new requirements on its sustainable water management. Thus, understanding the Huai River is a long and gradually improving process. Its future planning should keep absorbing new achievements of science and technology development, employing new technologies and methods, and gradually deepening our understanding of its fundamental principles. Water governance and adaptive water management will be new challenges and opportunities for the Basin in its river system change and flood control.

Three-Dimensional Water Quality Model Based on FVCOM for Total Load Control Management in Guan River Estuary,Northern Jiangsu Province

Guan River Estuary and adjacent coastal area(GREC) suffer from serious pollution and eutrophicational problems over the recent years.Thus,reducing the land-based load through the national pollutant total load control program and developing hydrodynamic and water quality models that can simulate the complex circulation and water quality kinetics within the system,including longitudinal and lateral variations in nutrient and COD concentrations,is a matter of urgency.In this study,a three-dimensional,hydrodynamic,water quality model was developed in GREC,Northern Jiangsu Province.The complex three-dimensional hydrodynamics of GREC were modeled using the unstructured-grid,finite-volume,free-surface,primitive equation coastal ocean circulation model(FVCOM).The water quality model was adapted from the mesocosm nutrients dynamic model in the south Yellow Sea and considers eight compartments:dissolved inorganic nitrogen,soluble reactive phosphorus(SRP),phytoplankton,zooplankton,detritus,dissolved organic nitrogen(DON),dissolved organic phosphorus(DOP),and chemical oxygen demand.The hydrodynamic and water quality models were calibrated and confirmed for 2012 and 2013.A comparison of the model simulations with extensive dataset shows that the models accurately simulate the longitudinal distribution of the hydrodynamics and water quality.The model can be used for total load control management to improve water quality in this area.

Study on Water Pollution Control of Huaihe River and Countermeasures

Huaihe 河是有一张大人口的中国的三条主要的河之一并且开发经济。由 1970 年代， Huaihe 河的水质量每天并且非常正在败坏水质量的 100 个严肃的污染事故发生了并且沿着河并且可怕地在居民的生产，生活和健康引起了无法估计的损失损坏了河的生态的系统。通过为超过 10 年的连续大规模处理， Huaihe 河里的水质量的恶化基本上被禁止了。不过， Huaihe 河里的水污染是总体上，为许多原因仍然很严肃包括特殊气候的条件，为河的水资源，过时的工业结构和腐烂的管理系统的可怕的缺乏，等等。这篇散文深深地分析 Huaihe 河的水污染是“长期”的并且提出为怎么连续地改进河的水质量的相应反措施的原因。最后，就算每项措施顺利被实现并且严格地，清洗实际上做 Huaihe 河的水并且逐渐地恢复它的正常生态、环境的功能，这篇散文主张它仍然花 30-50 年或甚至一个更长的时期。

Sediment control function of river notches

The purpose of this study is to investigate the control function and mechanisms of natural river notches. Physical and numerical experiments are analyzed in this study for two representative types of sediment events: high intensity and short duration Type A sediment disaster events, and low intensity and long duration Type B moderate non-disaster events. Two dimensionless parameters, sediment trapping rate and reduction rate of peak sediment transport, are defined to evaluate the sediment control function of river notches. Study results indicate that the contraction ratio of the notch has a significant influence on sediment control function, with high contraction ratios resulting in both high sediment-trapping and high reduction rates. River notches provide better sediment control during Type A events than Type B events. The sediment control mechanism of river notches is the result of multiple interactions among river flow, sediment transport, and riverbed variation. Analysis of these interactions supports the significant protection role of river notches on sediment control for disaster

A STUDY OF THE RELATION BETWEEN RIVER REGULATION AND FLOOD CONTROL

Flood control is closely related to the rising level of the upstream. Thechange of the main current and the inshore current velocity is induced by thecompletion of the regulation work. Yet Flood Control Departments pay muchmore attention to the extent,the range and the law of the inshore current velocity increase,especially in the river reaches which have arduous tasks of floodcontrol. Flood Control Departments object to constructing regulation work sucnas groynes,because they have always thought regulation work may lead to theincrease in the inshore current velocity.This paper intends to expound on theinfluences of regulation work on the extent,range and law of the inshore current velocity through analyzing the data obtained from the scale model tests ofthe Jiepai Reach in the middle of the Yangtze River and also discuss the possi-bility of limiting increase of the inshore current velocity through properly ad-justing regulaton work,thus we can correct evaluation of the influence of theriver regulation

A global satellite survey of density plumes at river mouths and at other environments: Plume configurations, external controls, and implications for deep-water sedimentation

The U. S. National Aeronautics and Space Administration(NASA) has archived thousands of satellite images of density plumes in its online publishing outlet called 'Earth Observatory' since 1999. Although these images are in the public domain, there has not been any systematic compilation of configurations of density plumes associated with various sedimentary environments and processes. This article, based on 45 case studies covering 21 major rivers(e.g., Amazon, Betsiboka, Congo [Zaire], Copper, Hugli [Ganges], Mackenzie, Mississippi, Niger, Nile, Rhone, Rio de la Plata, Yellow, Yangtze, Zambezi, etc.) and six different depositional environments(i.e., marine, lacustrine, estuarine, lagoon, bay, and reef), is the first attempt in illustrating natural variability of configurations of density plumes in modern environments. There are, at least, 24 configurations of density plumes. An important finding of this study is that density plumes are controlled by a plethora of 18 oceanographic, meteorological, and other external factors. Examples are: 1) Yellow River in China by tidal shear front and by a change in river course; 2) Yangtze River in China by shelf currents and vertical mixing by tides in winter months; 3) Rio de la Plata Estuary in Argentina and Uruguay by Ocean currents; 4) San Francisco Bay in California by tidal currents; 5) Gulf of Manner in the Indian Ocean by monsoonal currents; 6) Egypt in Red Sea by Eolian dust; 7) U.S. Atlantic margin by cyclones; 8) Sri Lanka by tsunamis; 9) Copper River in Alaska by high-gradient braid delta; 10) Lake Erie by seiche; 11) continental margin off Namibia by upwelling; 12) Bering Sea by phytoplankton; 13) the Great Bahama Bank in the Atlantic Ocean by fish activity; 14) Indonesia by volcanic activity; 15) Greenland by glacial melt; 16) South Pacific Ocean by coral reef; 17) Carolina continental Rise by pockmarks; and 18) Otsuchi Bay in Japan by internal bore. The prevailing trend in promoting a single type of river-flood triggered hyperpycnal flow is flawed because there are 16 types of hyperpycnal flows. River-flood derived hyperpycnal flows are muddy in texture and they occur close to the shoreline in inner shelf environments. Hyperpycnal flows are not viable transport mechanisms of sand and gravel across the shelf into the deep sea. The available field observations suggest that they do not form meter-thick sand layers in deep water settings. For the above reasons, river-flood triggered hyperpycnites are considered unsuitable for serving as petroleum reservoirs in deep-water environments until proven otherwise.

数字孪生永定河建设实践

数字孪生永定河建设是流域治理管理现代化的主要标志。围绕永定河生态修复与治理,构建数字孪生永定河,建设水利感知、数据底板、模型平台、知识平台、业务应用等内容,相关成果应用于永定河全年全线有水的生态水量调度与海河“23·7”流域性特大洪水的防洪调度,取得了初步成效。建议下一步从完善数据底板、完善防洪模型、提升防洪“四预”能力、提升水资源调度“四预”能力等方面加强数字孪生永定河建设,助力流域治理管理现代化。

Preliminary Study in Spatial Data Warehouse of Flood Control and Disaster Mitigation in Yangtze River Basin

Since 1990s,the spatial data warehouse technology has rapidly been developing, but due to the complexity of multi-dimensional analysis, extensive application of the spatial data warehouse technology is affected. In the light of the characteristics of the flood control and disaster mitigation in the Yangtze river basin, it is proposed to design a scheme about the subjects and data distribution of the spatial data warehouse of the flood control and disaster mitigation in Yangtze river basin, i.e., to adopt a distributed scheme. The creation and development of the spatial data warehouse of the flood control and disaster mitigation in Yangtze river basin is presented .The necessity and urgency of establishing the spatial data warehouse is expounded from the viewpoint of the present situation being short of available information for the flood control and disaster mitigation in Yangtze river basin.

黄河口泥沙的治理实践与评价

基于1855年以来黄河口的来沙量及其不同时期河口泥沙的输移分布特征,从入海流路、防洪安全、下游河道淤积和航道建设等4个方面对黄河口泥沙的灾害效应进行了论证分析。在总结黄河口泥沙治理历史的基础上,从防洪工程体系建设、强化河口河段泄洪排沙能力、减少河口来沙等3个方面对20世纪70年代中期以来黄河口所采取的泥沙处理对策进行了概括总结。结合国内外相关典型河口泥沙的治理经验和发展态势,从水沙关系调控、入海流路格局优化、利用海洋动力输沙和泥沙资源化利用等方面提出了今后黄河口泥沙的治理方向和主要策略。

The controls on the composition of biodegraded oils in the Liuhua11-1 Oilfield, Pearl River Mouth Basin, South China Sea

(1) The geochemical characteristics of extracted oils in three oil columns from the Liuhua11-1 Oilfield in the Pearl River Mouth Basin of South China Sea were analyzed in detail. The results show that the oil of Liuhua 11-1 Oilfield is generated from a single source rock, and belongs to maturate oil and their maturities have little difference.(2) The characteristics of saturated hydrocarbon gas chromatography,bulk composition, concentrations of biomarkers and gas chromatography–mass spectrometry of saturated hydrocarbon indicate that all samples studied were biodegraded, and the maximal level of biodegradation is less than PM level 6.(3) Bulk composition and the degree of biodegradation presented excellent gradient variations in the oil columns, and the highest degradation rates occurred at or near the oil–water contact(OWC). The key biomarkers of steranes and terpanes and maturity parameters of saturated hydrocarbon were not affected by degradation, which means that they are stable in slight to moderately biodegraded oils. Across the oilfield, the degree of biodegradation of LH11-1-3 was higher than that of LH11-1-1A and LH 11-1-4 in general.(4) We infer that the strong hydrodynamic conditions(tectonic control) and high reservoir temperatures(50–65 °C) are the primary controllers of the degree of oil biodegradation in the Liuhua 11-1 Oilfield and the late hydrocarbon accumulation may also have an important effect. The bulk composition and degree of biodegradation with excellent gradient variations in the oil columns were obviously controlled by the vertical distance from its in situ place to OWC. The highest supply of nutrient at the OWC results in high abundance of microorganisms and the highest degradation rate. And the lateral variation in level of biodegradation across the oil reservoir may be mainly control by the salinity of bottom water, the supply of nutrient and the energy of the bottom water.

Causes and typical control model of wind-drift sandy lands in abandoned channel of the Yellow River

黄河的放弃的隧道的历史的形成和发展被考察，它形成的原因和预防和控制的现在的状况在这篇论文被分析。在下一个时期把分析，关于控制的一些想法，批评问题和反措施基于这作为例子与二个典型控制模型一起被建议。我们在阻止并且控制风飘移建议那在这个区域的沙的陆地，强调应该是发展与一个极大地扩展的努力，再循环的经济。这应该认识到二个想法的联合，即集成与结构的调整与 desertification 作斗争农业并且农民的收入的增加。关键词风飘移沙的土地 - 形成的原因 - 控制模型 -

Risk prevention and control strategies for the severely affected areas of snow disaster in the Three Rivers Source Region(TRSR), China

Historically,frequent and heavy snow disaster(SD)has caused serious livestock death and casualties,resulting in a devastating impact on animal husbandry development in the Three Rivers Source Region(TRSR).From winter in 2018 to spring in 2019,the largest SD occurred in this area over the past 10 years,especially in core zones of the Lancang River Source Region.Field research results show that the main causes of the major SD include weak infrastructure(i.e.,roads,communications,warm sheds,and insufficient forage reserve),low rate of domestic animals for sale before the SD,and low loss settlement rate.SD occurrence could furtherly reduce the ability of disaster prevention,mitigation and relief of disaster loss.In the future,heavily affected SD areas should improve the forecasting ability of snowfall incidents,strengthen infrastructure construction,implement grass and livestock balance strategies,optimize livestock structure,improve loss settlement rate,and develop a modern compound model of animal husbandry development model that combines breeding,slaughtering and deep processing of animal product.

治涝导向的平原河网地区海绵城市实施路径探索——以宿迁市国家海绵城市示范系统化实施方案为例

针对平原河网地区的排涝特征与问题,在梳理构建治涝片区排水格局的基础上分类提出了针对性的治涝策略。对于具有一定坡度。在多数时期可以实现自排的治涝片区,采用“上蓄+中分+下排”模式,分段缓解排涝压力,提高城区排涝标准对于整体地势低洼,在多数时期很难自排的治涝片区,采用“建闸营圩,蓄排并举”模式,将雨水排口分散建设小型雨水泵站的模式调整为片区排涝主干河道末端建设大型排涝泵站的模式,充分利用片区内部河网的输送和调蓄能力,增强城区应对暴雨的韧性。

北江流域“2022·6·22”暴雨洪水分析

2022年6月19日,北江流域发生“2022年第2号洪水”,为1915年以来最大的洪水。为提高对北江流域暴雨洪水特性的认识,采用定性与定量相结合的方法对该场洪水的雨水工情进行研究。分析暴雨中心、洪水量级、洪水传播时间等特征,并与历史暴雨洪水进行对比。借助种子蔓延算法比较“理想凑泄”和“经验控泄”调度方案的调控效果,同时考虑水库动库容效应进行调洪演算。结果表明:造成本次洪水灾害的主要原因是累计雨量大、降雨强度大以及暴雨区域集中;根据“理想凑泄”规则调度飞来峡水库取得了显著效果,但需要考虑水库动库容的影响。研究成果可为北江流域防洪减灾以及制定调度规则等提供支持。