Search

The lower course of the Yellow River is a "hanging river" across the hinterland of China, and the safety of its flood control measures/systems is closely tied to the stability of the nation. Ensuring high-quality, sustainable development of the lower Yellow River floodplain while maintaining flood safety is crucial for the entire Yellow River Basin. Previous studies have primarily focused on the overall development of the Yellow River Basin or the economic–ecological coupling development of cities along the river, often neglecting the flood safety development of the floodplain. This study optimizes the socio-economic–flood-safety–ecological (SFE) system of the typical downstream Landong floodplain within the Yellow River Basin. The system dynamics model (SDM) can simulate the dynamic behavior of SFE systems by constructing mathematical models that incorporate feedback loops and time delays. The primary components include causal loop modules and stock-flow modules. Then, a coupling coordination degree model for the Landong floodplain is established using a comprehensive subjective and objective weighting method, assessing the SFE system's coordination under five scenarios: inertial development, economic development, environmental protection, flood safety, and sustainable development. The results of historical and validity tests indicate that the SDM can effectively simulate the coupling coordination degree of the SFE system. The study results suggest that the coupling coordination degree increases the most under the sustainable development scenario, indicating that the development of the Landong floodplain should not only focus on socio-economic growth, but should also consider flood safety and ecological concerns. In addition, comprehensive regulation from socio-economic, flood safety, and ecological environment indicators are necessary to achieve high-quality, coordinated development. This study has significant implications for policy formulation and management to achieve high-quality and sustainable development in the downstream floodplain of the Yellow River. [ABSTRACT FROM AUTHOR]

China has been facing a contradiction between its water supply and demand for a long time, and it is urgent that it builds a "water-saving society". Previous research on water pricing mainly focused on the policy level, only considering the supply and demand sides and ignoring the participation of local governments. Due to the inconsistent approval mechanisms, different times of cost formation, and lack of a scientific pricing relationship between multiple water sources and multiple users, with the current water pricing in China, it is difficult to solve the complex problem of water resource allocation. This study aimed to promote the qualitative supply of water and the reuse of reclaimed water, achieve a high-quality and low-cost water supply, and explore the role of water-pricing mechanisms in the regulation of multi-source water supply configurations. The mechanism of regulation is constructed for the complex, multi-source, multi-user water resource system, and a three-party game model is established among local governments, water supply enterprises, and water users. A reasonable pricing system with a rational price relationship is obtained, and Pinghu City in Zhejiang Province is taken as the research area. The prices of the external water supply to residential users, non-resident users, and special users are 4.48 CNY/m3, 6.28 CNY/m3, and 7.12 CNY/m3. The external supply prices for resident users, non-resident users, and special users are 3.81 CNY/m3, 5.25 CNY/m3, and 6.05 CNY/m3. The external supply price for non-resident users is 2.62 CNY/m3 for reclaimed water. The results of the study showed that when the government's contribution did not exceed the amount that it would have been without the inclusion of recycled water and the annual payment of water users did not exceed their ability to pay, the income of water suppliers increased by 69%. The three balanced objectives of rational water resource configuration by the local government, reasonable profit for the water supply enterprise, and reasonable payment by water users have been achieved. This study provides theoretical and methodological support for the implementation of water pricing for multi-source and multi-user water supplies in water-scarce areas. [ABSTRACT FROM AUTHOR]

Globally there is already a lot of pressure on water resources because of climate change, economic development, as well as an increasing global populace. Many rivers originate in the mountains, where snowfall fluctuations and the global climate's inherent unpredictability affect the hydrological processes. Climate change sensitivity has been recognized in recent years and would affect hydropower, such as humidity, cloudiness, and precipitation, that are considered; global warming emerges as one of the most important contributors to climate change. The Yangtze River supports rich biodiversity and provides important ecosystem services for human survival and development. In addition, climate changes, particularly short-term and long-term precipitation and temperature fluctuations, influence the snow regime and the hydrological development of river flow response at the basin and sub-basin scales. More precise this review focused to understand the hydropower potential, freshwater fisheries, and hydrological response of snow dynamics in snow-dominated basins. [ABSTRACT FROM AUTHOR]

The average annual temperature, precipitation, and evaporation patterns are some of the characteristics which indicate to a globe where climate is rapidly changing. It remains uncertain regarding how this rapid climate change will impact freshwater biota; however the consequences could be absolutely catastrophic. It is urgently needed to better adapt and maintain the fragile system that comprises the Mediterranean ecosystems. Water shortages and changes in the land use can impact water quality and the watershed's ecosystem. Changes in temperature and precipitation trends can increase the intensity of land use, the increase of water depletion, and the degradation of water quality. The effects of climate change on eco hydrology change runoff, evaporation, surface storage, and soil moisture, that all have immediate effects on the biota and biodiversity of region. It is supported by studies on eco hydrological impacts on local watersheds. The spatial pattern and surface water dynamics of watershed systems are utilized as a perspective using which to examine the hydrologic consequences. The impacts of climate change on rainfall, evaporation, soil humidity, lakes level, and quality of water, habitats, species migration, biodiversity, and economies have been investigated. The potential climatic impacts on watershed ecosystems are determined by a spatiotemporal assessment of variations in temperature and precipitation projections from a multimodal ensemble. The susceptibility of a watershed changed depending over its geographic region, terrain, and human influence. As such a manner of dealing with climate change, improving watershed systems could be beneficial. Various techniques have been proposed which can protect watersheds against by the consequences of climate and land use change. Strengthening ecosystem vulnerability requires knowledge of the Eco hydrological processes. This review anticipated effects of climate change on the Eco hydrology of watershed systems in the Mediterranean and implies strategies for adaptation to create the mechanisms more responsive. [ABSTRACT FROM AUTHOR]

Global warming is affecting animal populations worldwide, through chronic temperature increases and an increase in the frequency of extreme heatwave events. Reservoirs are essential for water security. All watersheds with reservoirs are impacted by their construction. These artificial ecosystems controlled by humans change considerably the natural terrestrial and aquatic ecosystem and systems and their biodiversity. The rapid increase in population growth, urbanization, and industrialization are accompanied by an increase in river discharges, which increases the total amount of pollutants. HMs contamination in aquatic environments, as well as the subsequent absorption of HMs into the food chain by aquatic creatures and people, endangers public health. Multiple uses of reservoirs promote benefits in terms of economic development, income, and employment. HMs in water can be ingested directly by aquatic species like fish and can also be ingested indirectly through the food chain; thus, it is much more important and required to conduct frequent monitoring of the aquatic environment. As a result, this review summarizes knowledge about the effects of cascade dams on river water temperature and increases on the stress physiology of fishes, and adaptation to climate change is also needed to produce more fish without global warming. [ABSTRACT FROM AUTHOR]

Climate change and rapid urbanization have increased pressure on drainage systems, posing new challenges to preventing and controlling urban waterlogging. In 2013, China proposed the Sponge City, a strategic measure for urban waterlogging control. This study quantifies the effects of stormwater management measures in runoff reduction for different levels of rainfall and conducts a one‐dimensional visual analysis of urban waterlogging risks. At the same time, the best cost‐effective scheme is determined based on life‐cycle cost, analytic hierarchy process, and regret decision theory. The results showed stormwater management measures could realize the function of runoff control and waterlogging prevention, especially under low precipitation. However, these measures were still not enough to eliminate waterlogging risk. Combined measures have stronger runoff control capabilities than single measures. Considering economic, environmental, and operational impacts comprehensively, the combined measures of bio‐retention (BR), permeable pavement (PP), and green roof (GR) were determined as the best cost‐effective scheme because of the lowest regret value. The proposed method is helpful to provide reference and decision‐making basis for the construction of sponge cities in the future. [ABSTRACT FROM AUTHOR]

To address the two problems of unclear delineation of sub‐catchment and complicated and cumbersome parameter rate determination in the Storm Water Management Model (SWMM), this study proposes a rapid construction method of SWMM based on the principle of single urban functional area combined with K‐means clustering algorithm, The research area is the southern part of Jinshui District, Zhengzhou City. The Hydrological Response Unit (HRU) contains only a single urban functional area, divided by combining the natural and social attributes of the urban surface. Calibrated uncertain parameters from 76 papers were selected as samples, and the K‐means clustering algorithm was used to cluster and calculate the parameter values, to improve the SWMM model, selecting three typical rainfall runoff processes for validation application. The results show that simulated runoff is consistent with measured runoff trends, with the NSE and R2 value scores of the flow processes of the three floods above 0.86 and the, locations and numbers of flooded nodes are consistent with the actual research. This provides a new idea and technical support for the construction of urban flood models in flood prevention and mitigation. The relevant results can provide scientific decision‐making reference for urban flood forecasting and warning. [ABSTRACT FROM AUTHOR]

Pakistan is water stressed, and its water resources are vulnerable due to uncertain climatic changes. Uncertainties are inherent when it comes to the modeling of water resources. The predicted flow variation in the Kunhar River Basin was modeled using the statistically decreased high-resolution general circulation model (GCM) as an input for the Hydrologiska Byråns Vattenbalansavdelning (HBV) model to assess the hydrological response of the Kunhar River Basin under prevailing climate changes. The model's best performance during the calibration and validation stages was obtained with a regular 0.87 and 0.79 Nash–Sutcliffe efficiency in the basin, respectively. Under the high-end emission scenario, a 122% increase was expected in evapotranspiration in the rising season of months during the winter period 2059–2079, and such developments were attributed to an immense increase in liquid precipitation and temperature. The model's output reflects a potential for basin stream flow in terms of increasing liquid precipitation up to 182% at the beginning of the monsoon season in the period 2059–2079 in the scenario of high-end emissions. Moreover, the study produced possible uncertainties in high-elevation zones, where the modeling of a catchment can lead to typical snow ablation and accumulation in future projections. This study revealed that the precipitation rate will increase annually, resulting in an increase in the summer stream flow over the basin, though snow is hardly expected to accumulate in the basin's future climate. [ABSTRACT FROM AUTHOR]

Runoff reduction in most river basins in China has become a hotpot in recent years. The Gushanchuan river, a primary tributary of the middle Yellow river, Northern China, showed a significant downward trend in the last century. Little is known regarding the relative contributions of changing environment to the observed hydrological trends and response on the runoff generation process in its watershed. On the basis of observed hydrological and meteorological data from 1965–2010, the Mann-Kendall trend test and climate elasticity method were used to distinguish the effects of climate change and human activities on runoff in the Gushanchuan basin. The results indicate that the runoff in the Gushanchuan Basin has experienced significant declines as large as 77% from 1965 to 2010, and a mutation point occurred around 1997; the contribution rate of climate change to runoff change is 12.9–15.1%, and the contribution rate of human activities to runoff change is 84.9–87.1%. Then we divided long-term data sequence into two stages around the mutation point, and analyzed runoff generation mechanisms based on land use and cover changes (LUCC). We found that the floods in the Gushanchuan Basin were still dominated by Excess-infiltration runoff, but the proportion in 1965–1997 and 1998–2010 decreased gradually (68.46% and 45.83% in turn). The proportion of Excess-storage runoff and Mixed runoff has increased, which means that the runoff is made up of more runoff components. The variation law of the LUCC indicates that the forest area increased by 49.61%, the confluence time increased by 50.42%, and the water storage capacity of the watershed increased by 30.35%. [ABSTRACT FROM AUTHOR]