Water Storage Reservoirs Research Articles

Comparative analysis and risk assessment of dam-break floods: Taking Pingshuijiang Reservoir as an example

Abstract Due to the huge potential energy associated with water storage in reservoirs, dam-break floods are often catastrophically destructive for people and structures downstream. This study aims to simulate and compare floods generated under various dam-break scenarios and their downstream impacts, taking Pingshuijiang Reservoir in southeastern China as an example. A two-dimensional hydrodynamic model is used to simulate the downstream evolution of floods under three dam-break scenarios, and the breach flood and downstream inundation process are analyzed. Gradual failure of the main dam leads to near-total inundation of the nearby town over c. 1 h, allowing time for warning and evacuation. Instantaneous failure of the main dam results in larger peak flow, greater submergence depth and faster inundation (20 min), leaving little time for warning/evacuation. Instantaneous failure of the auxiliary dam generates a much lower peak flow magnitude and, although the town is still largely submerged within 45 min, the shallow water depth and low velocity are conducive to rescue/evacuation. The results show significant variation in flood process and submergence due to dam size and failure mode that provide guidance for dam-break flood risk assessment and disaster avoidance planning.

New Economic Paradigm for Sustainable Reservoir Sediment Management

Water storage reservoirs can be either sustainable or exhaustible. In the absence of sediment management, reservoir storage is an exhaustible resource with long-term consequences. Previous economic planning of reservoirs essentially guaranteed non-sustainable solutions. This paper describes a new economic paradigm for economic assessments of new and existing reservoirs. The new economic paradigm provides a framework for comprehensive accounting of economic benefits and costs over a sufficiently long period of analysis, including cost estimates for dam decommissioning and lost benefits where sediments are not sustainably managed. A case study applies this framework to a hypothetical western US reservoir to quantitatively compare the status quo (i.e., no sediment management) with a selection of sediment management alternatives. Results indicate that sustainable sediment management can be less expensive than the consequences of ignoring sedimentation (e.g., eventual dam decommissioning and replacing lost storage capacity). Additional work shows that beginning sediment management within a decade of reservoir construction prevents the most severe impacts of sedimentation. An investigation of alternative discounting approaches indicates that the approach employed can have a significant impact on economic results.

Over half a century record of limnology data from Lake Powell, desert southwest United States: From reservoir filling to present day (1964–2021)

AbstractLake Powell is a large water storage reservoir in the arid southwestern United States. Here, we present a 58‐yr limnology dataset that captures water quality parameters from reservoir filling to present day (temperature, salinity, major ions, total suspended solids), as well as a 38‐yr record of Secchi depth, and a ~ 30‐yr record of nutrients, phytoplankton, and zooplankton assemblages. The dataset includes 5208 unique site visits spanning 258 unique sites of which 9 have been consistently visited. It also spans the establishment of an invasive bivalve (Dreissena bugensis, i.e. Quagga mussel) which was first detected in 2012. Given the general lack of long‐term data from lakes or reservoirs in arid regions, this dataset represents a unique contribution to regional, continental, and global‐scale limnology studies. As the hot drought in the desert southwest continues, we expect this dataset will inform water management decision‐making for this largest reservoir in the Upper Colorado River Basin.

Implementation and sensitivity analysis of the Dam-Reservoir OPeration model (DROP v1.0) over Spain

Abstract. The prediction of water resource evolution is considered to be a major challenge for the coming century, particularly in the context of climate change and increasing demographic pressure. Water resources are directly linked to the continental water cycle, and the main processes modulating changes can be represented by global hydrological models. However, anthropogenic impacts on water resources, and in particular the effects of dams-reservoirs on river flows, are still poorly known and generally neglected in coupled land surface–river routing models. This paper presents a parameterized reservoir model, DROP (Dam-Reservoir OPeration), based on Hanasaki's scheme to compute monthly releases given inflows, water demands and the management purpose. With its significantly anthropized river basins, Spain has been chosen as a study case for which simulated outflows and water storage variations are evaluated against in situ observations over the period 1979–2014. Using a default configuration of the reservoir model, results reveal its positive contribution in representing the seasonal cycle of discharge and storage variation, specifically for large-storage capacity irrigation reservoirs. Based on a bounded version of the Nash–Sutcliffe efficiency (NSE) index, called C2M, the overall outflow representation is improved by 43 % in the median. For irrigation reservoirs, the improvement rate reaches 80 %. A comprehensive sensitivity analysis of DROP model parameters was conducted based on the performance of C2M on outflows and volumes using the Sobol method. The results show that the most influential parameter is the threshold coefficient describing the demand-controlled release level. The analysis also reveals the parameters that need to be focused on in order to improve river flow or reservoir water storage modeling by highlighting the difference in the individual effects of the parameters and their interactions depending on whether one focuses on outflows or volume mean seasonal patterns. The results of this generic reservoir scheme show promise for modeling present and future reservoir impacts on the continental hydrology within global land surface–river routing models.

Assessment of the level of annual intake of tritium into the air from the surface of the lake Kyzyltash

Сайт «Озёра России». URL: https://ozera.info/lakes/ about/gvr/list-lakes/kyzyl-tash (Дата обращения 25.03.2022 г.) Екидин А.А., Антонов П.Л., Жуковский М.В. Оценка загрязнения атмосферы тритием при испарении воды с поверхности промышленных водоемов // Вопросы радиационной безопасности. 2012. № 3. С. 3-10. Андреева М.А. Озера среднего и Южного Урала. Челябинск, 1975. 270 с. Толстикова В.С. Кузнецов В.Н. Ядерное наследие на Урале: исторические оценки и документы. Екатеринбург, 2017. 400 с. Баторшин Г.Ш., Мокров Ю.Г., Алексахин А.И. Концепция вывода из эксплуатации водое мов-хранилищ ЖРО ФГУП «ПО «Маяк». VII Международный промышленный форум «АТОМЭКО – 2013». М., 2013. Радиационная обстановка на территории России и сопредельных государств в 2020 г. Ежегодник. Обнинск, 2021. 239 с. Чеботина М.Я., Николин О.А., Смагин А.И., Мурашова Е. Тритий в водоёмах производственного и комплексного назначения в районе ПО «Маяк» на Урале // Водное хозяйство России. 2011. № 4. С. 75-84. Vostrotin V.V., Yanov A.Y., Finashov L.V. Tritium in environmental objects in the area affected by FSUE Mayak Production Association in 2014-15 // Journal of Radiological Protection. 2021. Vol. 41, № 2. P. S56-S66. DOI 10.1088/1361-6498/ abe8c8. Иванов Н.Н. Об определении величины испаряемости // Известия Всесоюзного географического общества. 1954. Т. 86, № 2. вып. 1. С. 189–196. Сайт компании ООО «Расписание Погоды». URL: https:// rp5.ru. (Дата обращения 25.03.2022). Busigin A., Kalyanam K.M., Sood S.K. Estimation of the tritium release rate from a spill of tritiated water // Fusion Technology. 1992. Vol. 21, No 2P2. P. 512-517. DOI: 10.13182/FST92-A29798. Yoshinori S. Lake water mixing and tritium balance in lake Chuzenji // Geographical Review of Japan. 1983. Vol. 56-10. P. 667-678. The paper presents the results of research of the levels of tritium volume activity in lake Kyzyltash, a water storage reservoir for liquid radioactive waste from Mayak Production Association. Insufficient knowledge of the ways of migration of tritium from the reservoir and their quantitative assessment in modern conditions does not allow to fully objectively assess and predict the impact of the object of “nuclear heritage” on the population of Ozersk and the environment. The research was aimed at obtaining scientific results, which will be the starting point for the formation of a tritium monitoring program for industrial reservoirs by Mayak Production Association. The purpose of the study was assessement of the dynamics of tritium volume activity in the lake Kyzyltash, assessment of water balance parameters and the level of tritium intake into the air from its surface during the ice-free period. A total of 33 water samples were collected. The average tritium volume activity in 2021 made 1,57Е+04 Bq/l, SD – 1,1Е+03 Bq/l that more than 2 times exceeds the intervention level. A trend of decrease in the average monthly tritium volume activity in the reservoir during the observation period was revealed. In the course of calculations, it was stated that in the course of evaporation during the ice-free period the 196 TBq of tritium entered the air from lake Kyzyltash surface that is comparable with releases from all the Russia facilities (179 TBq) except Mayak Production Association. The obtained values of evaporated tritium make 13% from atmospheric tritium releases of Mayak Production Association in 2020. A total of ~12,2 million m3 had evaporated from the water reservoir surface in the study period. The model of dependence of tritium volume activity from time in lake Kyzyltash in 2021 and using of exponentially decreasing function allowed defining water balance of lake Kyzyltash in the ice-free period with 6,3 million m3 deficiency. Research of the model parameters allow prediction of sanitary and hygienic characteristics of the water reservoir from the point of view of radiation safety and calculation of water balance of the reservoir in certain periods of time.

Dynamics of sediment formation in natural lakes and reservoirs

The rate of deposition of sediments in the water flow has a great influence on the flow carrying capacity, service life and coefficient of useful work of natural channels. In addition, precipitation and land use change lead to the acceleration of the erosion process and directly affects the rate of sedimentation of the umbilical cord. In this literature, attention was paid to studies analyzing the factors influencing the volume of water storage in reservoirs and natural lakes. 14 studies found an increase in the rate of sediment deposition and 13 found a decrease. 83.3% of the articles studied studied natural lakes and found a recent increase in sedimentation, including 54.5% of the articles on impoundment reservoirs reported a recent increase in sedimentation. determined to decrease. Land use change has been cited as the main cause of the increase in sediments, and climate change has also had a significant impact. In 44% of the reviewed articles, it was found that reservoirs and canals are losing their water intake capacity as a result of the increase in sediments, resulting in siltation. In the following studies, it was found that as a result of increased sedimentation, the process of silting in canals and water storage structures increases significantly and they lose their capacity to carry water.

Near-term forecasting of water reservoir storage capacities using long short-term memory

Abstract Predicting reservoir storage capacities is an important planning activity for effective conservation and water release practices. Weather events such as drought and precipitation impact water storage capacities in reservoirs. Predictive insights on reservoir storage levels are beneficial for water planners and stakeholders in effective water resource management. A deep learning (DL) neural network (NN) based reservoir storage prediction approach is proposed that learns from climate, hydrological, and storage information within the reservoir’s associated watershed. These DL models are trained and evaluated for 17 reservoirs in Texas, USA. Using the trained models, reservoir storage predictions were validated with a test data set spanning 2 years. The reported results show promise for longer-term water planning decisions.

Drinking water quality monitoring of centralized water storage reservoirs in various zones of the National University

Physico-chemical and microbiological pollutants may compromise quality of drinking water. This study aims to highlight various physico-chemical and microbial parameters of drinking water samples from centralized water storage reservoirs of National University. Major water quality parameters which were examined in this study includes pH, Electrical conductivity (EC), Turbidity, Total suspended solids (TSS), Total dissolved solids (TDS), Dissolved oxygen (DO), Residual chlorine, Hardness, Alkalinity. Moreover, microbial analysis of water samples was also carried out through Most Probable Number technique (MPN). Results show that all the physico-chemical parameters were within prescribed limits of World Health Organization and Pakistan Drinking Water Quality Standards (WHO/PDWQS) in both underground and overhead water storage reservoirs except DO ( 9.05-9.2 and 9.05-9.1 mg/L ), TSS (10-20 and 3.3-10 mg/L) and residual chlorine (0.08-0.14 and 0.19-0.28 mg/L) respectively. The MPN index values for both underground and overhead water storage reservoirs ranges between 16- >23 and 1.1-12 respectively and it shows high microbial contamination in water due to low detection of residual chlorine. The results highlight that water from centralized water storage reservoirs of National University is unfit for drinking purposes. Statistical analysis such as paired t-test also reveals that water quality parameters from underground and overhead storage reservoirs are not significantly different from each other except EC and TDS having P values <0.05. It is necessary to safeguard water contamination in water storage reservoirs by monitoring regular inspections and chemical cleaning of water storage reservoirs otherwise it will cause serious threats to well-being of the community.
 Key words: water storage reservoirs, drinking water, microbial quality of water, physico-chemical parameters, paired t-test

Accessing the Time-Series Two-Dimensional Displacements around a Reservoir Using Multi-Orbit SAR Datasets: A Case Study of Xiluodu Hydropower Station

The construction of large-scale hydropower stations could solve the problem of China’s power and energy shortages. However, the construction of hydropower stations requires reservoir water storage. Artificially raising the water level by several tens of meters or even hundreds of meters will undoubtedly change the hydrogeological conditions of an area, which will lead to surface deformation near the reservoir. In this paper, we first used SBAS-InSAR technology to monitor the surface deformation near the Xiluodu reservoir area for various data and analyzed the surface deformation of the Xiluodu reservoir area from 2014 to 2019. By using the 12 ALOS2 ascending data, the 100 Sentinel-1 ascending data, and the 97 Sentinel-1 descending data, the horizontal and vertical deformations of the Xiluodu reservoir area were obtained. We found that the Xiluodu reservoir area is mainly deformed along the vertical shore, with a maximum deformation rate of 250 mm/a, accompanied by vertical deformation, and the maximum deformation rate is 60 mm/a. Furthermore, by analyzing the relationship between the horizontal deformation sequence, the vertical deformation sequence, and the impoundment, we found the following: (1) Since the commencement of Xiluodu water storage, the vertical shore direction displacement has continued to increase, indicating that the deformation caused by the water storage is not due to the elastic displacement caused by the load, but by irreversible shaping displacement. According to its development trend, we speculate that the vertical shore direction displacement will continue to increase until it eventually stabilizes; (2) Vertical displacement increases rapidly in the initial stage of water storage; after two water-storage cycles, absolute settlement begins to slow down in the vertical direction, but its deformation still changes with the change in the storage period.

High-resolution water level and storage variation datasets for 338 reservoirs in China during 2010–2021

Abstract. Reservoirs and dams are essential infrastructure in water management; thus, information of their surface water area (SWA), water surface elevation (WSE), and reservoir water storage change (RWSC) is crucial for understanding their properties and interactions in hydrological and biogeochemical cycles. However, knowledge of these reservoir characteristics is scarce or inconsistent at the national scale. Here, we introduce comprehensive reservoir datasets of 338 reservoirs in China, with a total of 470.6 km3 storage capacity (50 % Chinese reservoir storage capacity). Given the scarcity of publicly available gauged observations and operational applications of satellites for hydrological cycles, we utilize multiple satellite altimetry missions (SARAL/AltiKa, Sentinel-3A and Sentinel-3B, CroySat-2, Jason-3, and ICESat-2) and imagery data from Landsat and Sentinel-2 to produce a comprehensive reservoir dataset on the WSE, SWA, and RWSC during 2010–2021. Validation against gauged measurements of 93 reservoirs demonstrates the relatively high accuracy and reliability of our remotely sensed datasets. (1) Across gauge comparisons of RWSC, the median statistics of the Pearson correlation coefficient (CC), normalized root mean square error (NRMSE), and root mean square error (RMSE) are 0.89, 11 %, and 0.021 km3, with a total of 91 % validated reservoirs (83 of 91) having good RMSE from 0.002 to 0.31 km3 and NRMSE values smaller than 20 %. (2) Comparisons of WSE retracked by six satellite altimeters and gauges show good agreement. Specifically, the percentages of reservoirs having good and moderate RMSE values smaller than 1.0 m for CryoSat-2 (validated in 30 reservoirs), SARAL/AltiKa (9), Sentinel-3A (34), Sentinel-3B (25), Jason-3 (11), and ICESat-2 (26) are 77 %, 75 %, 79 %, 87 %, 81 %, and 82 %, respectively. By taking advantages of six satellite altimeters, we are able to densify WSE observations across spatiotemporal scales. Statistically, around 96 % of validated reservoirs (71 of 74) have RMSE values below 1.0 m, while 57 % of reservoirs (42 of 74) have good data quality with RMSE values below 0.6 m. Overall, our study fills such a data gap with regard to comprehensive reservoir information in China and provides strong support for many aspects such as hydrological processes, water resources, and other studies. The dataset is publicly available on Zenodo at https://doi.org/10.5281/zenodo.7251283 (Shen et al., 2021).

Flow regime changes in the Lancang River, revealed by integrated modeling with multiple Earth observation datasets

The flow regime change of rivers, especially transboundary rivers, affected by reservoir regulations is evident worldwide and has received much attention. Investigating dam-induced flow regime alterations is essential for understanding potential adverse downstream effects and facilitating dialogue around coordinated water use in transboundary basins, such as the Lancang River Basin (LRB). This study explored the value of combining several types of satellite Earth observation (EO) datasets that monitor different water balance components to constrain the parameter space of lumped conceptual hydrological models. Thus, we aimed to reconstruct the natural flow regimes upstream and downstream of the cascade reservoirs. Specifically, reservoir water storage changes were first estimated using satellite imagery and altimetry datasets. Then, storage changes were combined with hydrological model simulations of reservoir inflow to estimate the regulated flow regime downstream. Our results showed that integrated hydrological modeling combined with EO datasets exhibited better overall performance. Continuous warming and drying of the LRB resulted in a decrease in discharge of approximately 47 %. By comparing the simulated natural and regulated flow regimes, we revealed the pivotal role of the Xiaowan and Nuozhadu reservoirs in regulating natural flows. The wet season shortens (approximately 45 days), the flood peak flattens, and the low flow in the dry season has primarily increases. The two reservoirs attenuated 50 % of the flood peaks in the wet seasons and mitigated droughts by releasing up to 100 % of the natural flows in the dry seasons at the China–Laos border. Overall, these results enhance the understanding of upper reservoir operation, and the approaches can be applied to studies of dammed basins under climate change scenarios when knowledge of the upstream area is limited.

A Strategy to Quantify Water Supply of an Agricultural Reservoir for Integrated Water Management Policy

A data-driven approach is required to scientifically manage agricultural water resources in accordance with the integrated water management policy of South Korea. In this study, a quantification strategy is presented to calculate reservoir supply by comparing the results with the actual reservoir water storage. Strategies considering current calculation methods were divided into canal flow measurement (S1), theoretical flow rate (S2), water storage decrease in field practice (S3), and water demand in design practice (S4), utilizing water levels of the reservoir and its canal and the level–flow rate curve obtained from surveying the canal flow. Each strategy was assessed through hydrological verification of reservoir water balance modeling. Based on the determination coefficient (R2), Nash–Sutcliffe efficiency (NSE), and relative error (RE) values, the S1 method was found to be the most suitable. S2 had lower reliability than S1, while S3 and S4 satisfied neither R2 nor NSE and had a larger RE than S1 and S2. To accurately quantify agricultural water supplies, the importance of directly measuring reservoir canal flows must be emphasized using automatic water level and flow gauges in canals. This study provides insights into more scientific management of agricultural reservoir water supplies and more effective monitoring of agricultural water usage.

Experimental Study on the Evolution Law of Coal Mine Underground Reservoir Water Storage Space under the Disturbance and Water—Rock Interaction Effect

The void of the cracked rock mass of the goaf is the main water storage space of underground reservoirs, which is in a time-space dynamic evolution process. Before the formation of the underground reservoir, the water storage space was primarily affected by disturbances. After the safe operation of the coal mine underground reservoir, the water level of the mine rises and falls repeatedly and the water storage space is affected by the water-rock interaction. To study the void evolution law of a cracked rock mass under mining disturbance and the compaction and void deformation characteristics of caving gangue under the effect of the water-rock interaction, a simulation test of a coal mine underground reservoir is conducted. Furthermore, the rupture motion law and movement deformation characteristics of the overburden during coal mining are analyzed. The digital image method and fractal theory are introduced to describe the fractal characteristics of the rock mass void of the caving zone, fracture zone, and entire goaf during the mining process. Five prototype gangue samples with different immersion times are prepared with the same grain size grading as the similar model caving gangue. The influence of the immersion times on the compaction characteristics and evolution law of the void rate of the gangue are also studied. Based on the parameter fitting method, the stress–strain relationship equation of the gangue sample and void rate-stress relationship equation of the cylindrical gangue sample, considering the influence of the immersion times, are constructed. The results show that the overburden of the model is of a “two zone” structure and the entire structure moves and sinks asymmetrically in a “∩” shape. As the advancing distance of the working face increased, the fractal dimensions of the rock mass void of the caving zone and entire goaf increased logarithmically, and the fractal dimension of the rock mass void of the fracture zone first increased rapidly (60–80 cm) and then decreased linearly (80–200 cm). As the immersion time increased, the saturated moisture content and density of the gangue samples increased logarithmically and exponentially, respectively. Under the same stress, the strain of the gangue sample increased gradually, and the void rate decreased gradually (except for the initial loading).

Physicochemical parameters of water in earthen ponds and concrete water storage reservoirs in Bakolori irrigation project, Zamfara state, north western Nigeria

Physicochemical Parameters of large Earthen Ponds and Concrete water storage reservoirs (CWSRs) of Bakolori Irrigation Project (BIP) were investigated from March 2019 to February 2020. Four sampling stations were randomly selected from the two water body types. Air and Water Temperature, Dissolved Oxygen (DO), pH, Electrical Conductivity (EC), Water Depth, Total Dissolved Solids (TDS), Transparency & Salinity were determined in situ, while water samples were collected monthly from the eight sampling stations and taken to the laboratory for analysis of Alkalinity, Hardness, Nitrate-N and Phosphate-P. The data collected were arranged on the bases of two seasons (dry & wet) and five sub-seasons, namely: Early dry (Oct - Dec); mid dry (Jan & Feb); late dry (March - May); Early rainy (June & July) and flood period (Aug & Sept), and subjected to T test analysis using Minitab statistical package. Results were compared with the water quality standards for Human consumption, aquatic life and fish production aquatic life and aquaculture. Results showed that with the exception of high Turbidity (low transparency) due to mud & debris in the water storage reservoir in some sub seasons, the water bodies were suitable for Aquatic life and Aquaculture. But partly unsafe for human consumption. The study recommends continuous assessment of the water bodies for physicochemical parameters. It further recommends the use of several water storage reservoirs for mudfish (such as Clarias and Hetrobranchus species) production instead of leaving them redundant as observed during the study period.

The mechanics of diurnal thermal stratification in river pools: Implications for water management and species conservation

AbstractWe examined conditions that form or prevent thermal stratification in river pools using field measurements, statistical modelling, and three‐dimensional (3D) computational fluid dynamics (CFD) modelling. Our motivation is to identify variables that control stratification for exploitation to enhance or prevent thermal gradients as needed to benefit species in rivers. One study pool (UT) is located above water storage reservoirs and receives natural flows, and the other pool (PT) is regulated and receives unnaturally high, cold water in summer; both pools are on the Trinity River, California. Thermal stratification formed in UT pool in spring at a critical flow of 1.01 m3/s, peaked at 8.1°C in summer, and exhibited diurnal formation and destruction under sub‐critical flows until fall. At PT pool, the 14.2 m3/s baseflow caused mixing that prevented stratification and formed a spatially homogenous thermal environment. Statistical analyses indicated the daily range in air and inlet water temperature at UT pool best correlated with the occurrence and strength of stratification but were progressively irrelevant as flows increased above the critical value. The validated CFD model was used to reproduce the diurnal stratification and explain the processes involved. The CFD model correctly predicted the observed critical flow and replicated the dynamics of stratification at UT pool and isohyets observed at PT pool. The CFD results also confirmed that low flows are the main variable for stratification to form, and the daily range in inlet water temperature drives the strength of the thermal gradient. The model estimated a critical discharge at PT pool of 2.0 m3/s, twice that for UT pool owing to its 2.6‐times larger area, suggesting critical flows scale with pool size. Results showed that releasing critical and lower flows in summer on regulated streams may conserve water and provide thermal gradients that benefit poikilothermic species; alternately, higher than critical flows can prevent stratification where needed to improve water quality.

Impacts of Underground Reservoir Site Selection and Water Storage on the Groundwater Flow System in a Mining Area—A Case Study of Daliuta Mine

The natural ecological conditions in the Shendong mining area in China are very fragile, and water resources are seriously lacking. As the production scale of the Shendong mine continues to expand, the demand for water for production and living is also increasing; however, the available surface and underground water is decreasing, and the water scarcity in the Shendong mine is becoming increasingly apparent. Obtaining water resources is a major technological challenge for green mining. The underground reservoir is a new type of underground water conservancy project, and the water shortage in China’s coal mine pits is resolved by underground reservoirs, which also makes a substantial contribution to the effective utilization of water resources. How the construction of underground reservoirs affects the groundwater system in a mining area has become one of the most important factors to consider when finding sites for underground reservoirs. In this study, we took the Daliuta Coal Mine as an example. A numerical model based on the hydrogeological conditions in the mining area was developed to determine the effects on groundwater using FEFLOW software via the finite element method. The model was used to analyze the impacts of coal seam mining thickness, overlying lithology, water-storage range and the water level of the underground reservoir on the groundwater flow system in the mining area. The results indicate that the thickness of the coal seam mining and the lithology of the overlying reservoir both had a significant effect on the upper aquifer system. The water-storage range and water level of the underground reservoirs were the main influences on the lower aquifer system. The results prove that underground reservoir storage had a good effect on water retention in the groundwater system in the mining area, and was able to achieve the desired result of storing groundwater and reducing water loss. It also had a positive feedback effect on the mining area’s environment.

THE PUMPED-STORAGE HYDRO POWER PLANT MODEL WITHIN IN THE POWER SYSTEM RELIABILITY AND AVAILABILITY MODEL

This paper deals with a model that comprises the pumped-storage hydro power plants in the power system reliability and availability calculations, as well as a model of the impact of inflow deficiency and water storage risks on the operational planning of such plants within the framework of operational planning systems for periods of up to one year. The impact of inflow uncertainties is related to the characteristics of watercourses where the water storage reservoirs and hydro power plants are built, but also to the operation cycles and possible operation modes in the system.

Fabrication of green nanoinsecticides from agri-waste of corn silk and its larvicidal and antibiofilm properties

Abstract The corn silk (CS) is composed of the thread-like stigmas of female inflorescences of Zea mays L. and represents an important waste material from maize crop production that can be recycled in further applications. In this research, the CS was used for the bio-fabrication of Ag nanoparticles (AgNPs) that were evaluated against (I–V) larval instars and pupae of the mosquito vector Aedes aegypti. CS-AgNPs were characterized by UV-Vis spectroscopy, TEM, EDAX, XRD, FTIR, DLS, and zeta potential analysis. Z. mays extract analyzed by gas chromatography mass spectrometry reveals 14 compounds. The larvicidal effectiveness of CS-fabricated AgNPs was 2.35 μg·mL−1 (I Instar) to 6.24 μg·mL−1 (pupae). The field application in water storage reservoirs of both CS extracts and CS-AgNPs (10 × LC50) led to a 68–69% reduction in larval density after 72 h post-treatment. Ecotoxicological impact of CS-fabricated AgNPs was evaluated on the predatory efficacy of Poecilia reticulata on all the larval instars and pupae of Ae. aegypti. Finally, CS-AgNPs were tested to elucidate its anti-biofilm attributes. The CS-AgNPs at 125 μg·mL−1 showed a biofilm inhibition of 90% on S. aureus and 79% on S. epidermidis. These results support the use of CS-AgNPs for futuristic green alternative to mosquito vector management.

Future runoff forecast in Hanjiang River Basin based on Wetspa model and CMIP6 model

In order to comprehensively consider the impact of human activities on runoff simulation and improve the accuracy of runoff simulation, so as to make a more accurate prediction of the future runoff of the Hanjiang River Basin, this study improved the reservoir module of the Wespa model, adding two parts: reservoir inflow data correction and water storage and outflow data calculation without measured data. Use the improved model to verify its applicability to the Hanjiang River Basin, then, choose the ones who has the most familiar trend with the historical data in the future climate model data (CMIP6). Put the selected data in the model to predict the runoff of Hanjiang River from 2021 to 2060. By analyzing the future runoff trend of Ankang, Huangjiagang and Huangzhuang in the Hanjiang River Basin from 2021 to 2060 and the changes of average runoff, seasonal runoff and monthly runoff compared with the historical period (1981–2020), the conclusions drawn are as follows: 1) The improved Wetspa model has good applicability in the Hanjiang River Basin; 2) The future runoff of Ankang section is decreasing, while that of Huangjiagang and Huangzhuang sections is increasing; 3) Compared with the reference period, the average runoff of the three sections in the future shows an increasing trend, which indicates that there will be flood risk in the future; 4) Compared with the reference period, the runoff proportion of the three sections will increase in spring and winter, and decrease in autumn. Attention should be paid to the risk of drought in autumn. In terms of months, the proportion of runoff from April to June increases, decreases from September to November, and increases and decreases in other months are uncertain.

Allocation and Scheduling of the Colorado River System

Generally, dams serve as reservoirs for water storage. The Colorado River Basin is currently in a state of continuous drought, and if the five states of AZ, CA, WY, NM and CO maintain the agreements made hundreds of years ago, there will not be enough water to supply in the near future. We propose a multi-objective programming algorithm under inequality constraints, under the condition that the sum of the competition coefficients is minimized, we solve the proportion of water resources that should be cut for general water usage and hydropower production at different water scarcity rates. We develop some policies to deal with water scarcity. We use the univariate analysis method to rationally analyze and reconstruct our model according to three different scenarios, and finally predict different situations, like additional water supply is needed or whether there will be more water flowing to the Gulf of California.