Higher Water Yield Research Articles

Assessment of Water-Related Ecosystem Services and Beneficiaries in the Hainan Tropical Rainforest National Park

Tropical rainforests are of vital importance to the environment, as they contribute to weather patterns, biodiversity and even human wellbeing. Hence, in the face of tropical deforestation, it becomes exigent to quantify and assess the contribution of ecosystem services associated with tropical rainforests to the environment and especially to the people. This study adopted a nuanced approach, different from traditional economic valuations, to estimate the water-related ecosystem services (WRESs) received by the people from 2010 to 2020 in the Hainan Tropical Rainforest National Park (HTRNP). The study focused on water yield, soil conservation, and water purification using InVEST, the SCS-CNGIS model, and spatial analysis. The results show (1) significant land cover changes within the HTRNP, as forest decreased by 4433 ha and water bodies increased by 4047 ha, indicating the active presence of human activities. However, land cover changes were more pronounced within the 5 km buffer area around the HTRNP, suggesting the effectiveness of the tropical rainforest conservation efforts in place. (2) The water yield of the HTRNP in the years studied decreased by 307.03 km3, based on the water yields in 2010 and 2020, which were 5625.7 km3 and 5318.7 km3, respectively. (3) Change detection showed that runoff mitigation in the rainforest has a negative mean (−0.21), indicating a slight overall decrease in soil conservation and runoff mitigation in the rainforest from 2010 to 2020; however, the higher curve number indicates areas susceptible to surface runoff. (4) The ecological effectiveness of water purification to absorb and reduce nitrogen load was better in 2020 (145,529 kg/year), as it was reduced from 506,739 kg/year in 2010, indicating improved water quality. (5) Population growth is more pronounced in areas with high water yields. Overall, the proposed framework has shown that the water yield potential of the HTRNP can meet the water consumption demands of people and industries situated within the buffer area. However, analysis of the study shows that it does not meet the crop water requirements. This study provides insights for decision makers in identifying potential beneficiaries and the essence of effective area-based conservation measures, and the proposed framework can be applied to any area of interest, offering a different approach in ecosystem services assessment.

Green Synthesis of New Derivatives of Iminothiazole Using Cefixime and Removing Organic Pollutants from Aqueous Environment by Employing Cu@KF/Clinoptilolite NPs.

In this research, multicomponent reactions of cefixime, isothiocyanates, and alkyl bromides were carried out for the synthesis of new iminothiazole derivatives with high yields in water as the solvent at room temperature in the presence of catalytic amounts of Cu@KF/CP NPs as catalysts. Also, the ability of Cu@KF/Clinoptilolite nanoparticles (NPs) to adsorb and remove 4-NP and cefixime from water was investigated. The Cu@KF/Clinoptilolite nanoparticles were synthesized by employing a water extract of Petasites hybridus rhizomes. For this experiment, all of the components obtained from Fluka and Merck were subjected to further purification. The antibiotic used in this investigation, cefixime, was obtained from a pharmaceutical facility situated in Sari, Mazandaran, Iran. The antibiotic factory is located in Sari City, Iran. All solutions were prepared using distilled water. The shape of Cu@KF/CP nanoparticles was analyzed using images obtained from a Holland Philips XL30 scanning electron microscope. An analysis was performed on the crystalline structure of Cu@KF/CP nanoparticles (NPs), and a room temperature X-ray diffraction (XRD) examination was carried out utilizing a Holland Philips Xpert X-ray powder diffractometer. The X-ray diffraction (XRD) examination was conducted using CuK radiation, which has a wavelength of 0.15406 nm. The analysis covered a 2ε angle range from 20 to 80°. The nanostructures that were produced were chemically analyzed using X-ray energy dispersive spectroscopy (EDS) with an S3700N equipment. The morphology and dimensions of Cu@KF/CP nanoparticles were characterized using a Philips EM208 transmission electron microscope operated at an acceleration voltage of 90 kV. The primary objective of this study was to develop a sustainable approach for producing new iminothiazole derivatives 4. This was achieved using a highly efficient three-component reaction combining cefixime 1, isothiocyanates 2, and alkyl bromides 3. The reaction was carried out in water at ambient temperature, using Cu@KF/CP NPs as a highly effective catalyst, leading to excellent yields. Moreover, the study findings showed that the synthesized compounds demonstrated a significant antioxidant activity compared to conventional antioxidants. The antibacterial efficacy of the synthesized compounds was evaluated against both Gram-positive and Gram-negative bacteria. Furthermore, Cu@KF/CP nanoparticles were utilized to adsorb CFX and 4-NP from water-based solutions. This study showcases the effective synthesis of innovative iminothiazole derivatives through the use of multicomponent reactions, involving the combination of cefixime, isothiocyanates, and alkyl bromides. The reactions were conducted in a water-based solvent. The reactions were carried out at room temperature, utilizing Cu@KF/CP NPs as catalysts. The Cu@KF/CP nanoparticles, a newly developed heterogeneous nanocatalyst, were synthesized and evaluated utilizing X-ray diffraction (XRD), fieldemission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM) research techniques. Cu@KF/CP nanoparticles are utilized to adsorb CFX and 4-NP from water-based solutions. The objects were manufactured using a straightforward and uncomplicated approach. The BET surface area of Cu@KF/CP NPs was measured to be 201.8 m2/g. The experimental equilibrium data was evaluated by applying the isotherms of the Langmuir, Freundlich, Dubinin-Radushkevich, and Redlich-Peterson models. Additionally, we examined the catalytic efficiency of Cu@KF/CP nanoparticles (NPs) in reducing various colors in water.

Extremely Fast Wicking Self‐Layered Interpenetrating Network Hydrogel for Rapid All Day Collection of Atmospheric Water

AbstractHygroscopic salt hydrogel photothermal composites and related technology are a promising pathway for water harvesting. However, due to the overly cumbersome preparation process, the distribution of the surface photothermal layer is difficult to control and the photothermal efficiency is low. In this paper, a method is proposed to greatly simplify the preparation process of photothermal layer hydrogels and improve their atmospheric water harvesting performance by constructing temperature‐sensitive interpenetrating networks. Due to the decomposition of some reversible hydrated structures in the network during heating and warming, carbon nanotubes move autonomously to form a layered structure with a photothermal effect on the upper surface, which can return to its original state after cooling and remain stable at room temperature or under solar illumination. Compared with hydrogels with general layered structure or overall distribution of photothermal materials, agar/GG/PAM/CNT hydrogel has faster moisture adsorption efficiency and higher desorption efficiency, and during the 24 h continuous sorption–desorption cycle is capable of achieving high water yield of 2.57 Lwater kgsorbents−1 day−1, superior to most recent hydrogel adsorbents. Simplifying the preparation process while maintaining high efficiency, while greatly improving photothermal performance, paves the way for cost‐effective mass production applications for a wide range of hygroscopic salt‐hydrogel photothermal composites.

Coupled water-habitat-carbon nexus and driving mechanisms in the Tarim River Basin: A multi-scenario simulation perspective

Human activity has transformed natural land use patterns and exerted a significant impact on the mechanisms underlying ecosystem service (ES) provisioning. This has disrupted the equilibrium between human development and ecological protection and hasled to further degradation of desert ecosystems endemic to arid regions. In this study, we employed the three SSP-RCP scenarios provided by CMIP6 to represent varying rates of development within the Tarim River Basin (TRB) and modeled land use in 2050 based on the coupled system dynamics (SD) + patch-generating land use simulation (PLUS) + InVEST model. A dynamic simulation of the trade-off/synergy between key land use types and ESs in the ecologically vulnerable areas of the TRB was performed to identify the impacts of the individual effects of single factors and the scale effects of multiple factors on ESs. The results showed that (1) in the SSP126, SSP245, andSSP585 scenarios, the ratio of outflows to inflows of converted unused land gradually increased in the following periods:79.28 %, 79.42 %, 79.54 %in 2020–2030; 96.19 %, 91.62 %, 66.07 %in 2030–2040; and 93.76 %, 91.65 %, 60.96 %in 2040–2050, respectively.(2) A high water yield (WY) was observed in the highland mountains; high habitat quality (HQ) was observed in the highland mountains, along the Tarim River, and around cities; high carbon storage (CS) was observed in the highland mountains, along the Tarim River, and in urban areas. (3) Under the three scenarios, WY, HQ, and CS were mainly affected by environmental factors, with the highest single-factor tests represented by temperature (0.594; 0.595; 0.596), precipitation(0.582; 0.589; 0.590); NDVI(0.312; 0.295; 0.299), soil erosion(0.227; 0.221; 0.219); and NDVI(0.298; 0.282; 0.310), soil erosion(0.122; 0.125; 0.132), respectively. Additionally, the interaction factors with the highest explanatory power for WY, HQ, and CS were precipitation ∪ NDVI (0.73); elevation ∪ NDVI (0.37); and soil ∪ NDVI (0.31), respectively. Moreover, the human aggregation level exerted positive (0.117), negative (−0.173), and negative (−0.286) impacts on WY, HQ, and CS, respectively. The results show that the combination of GeoDetector and the partial least squares structural equation modeling (PLS-SEM) provides a complementary and creative framework for investigating the driving mechanisms of ecosystems.

The Gas Production Characteristics of No. 3 Coal Seam Coalbed Methane Well in the Zhengbei Block and the Optimization of Favorable Development Areas

The characteristics and influencing factors of gas production in CBM wells are analyzed based on the field geological data and the productivity data of coalbed methane (CBM) wells in the Zhengbei block, and then the favorable areas are divided. The results show that the average gas production of No. 3 coal seam CBM wells in the study area is in the range of 0~1793 m3/d, with an average of 250.97 m3/d; 80% of the wells are less than 500 m3/d, and there are fewer wells above 1000 m3/d. The average gas production is positively correlated with gas content, critical desorption pressure, permeability, Young’s modulus, and Schlumberger ratio, and negatively correlated with fracture index, fault fractal dimension, Poisson’s ratio, and horizontal stress difference coefficient. The relationship between coal seam thickness and the minimum horizontal principal stress is not strong. The low-yield wells have the characteristics of multiple pump-stopping disturbances, unstable casing pressure control, overly rapid pressure reduction in the single-phase flow stage, sand and pulverized coal production, and high-yield water in the later stage during the drainage process. It may be caused by the small difference in compressive strength between the roof and floor and the coal seam, and the small difference in the Young’s modulus of the floor. The difference between the two high-yield wells is large, and the fracturing cracks are easily controlled in the coal seam and extend along the level. The production control factors from strong to weak are as follows: critical desorption pressure, permeability, Schlumberger ratio, fault fractal dimension, Young’s modulus, horizontal stress difference coefficient, minimum horizontal principal stress, gas content, Poisson’s ratio, fracture index, coal seam thickness. The type I development unit (development of favorable areas) of the Zhengbei block is interspersed with the north and south of the block on the plane, and the III development unit is mainly located in the east of the block and near the Z-56 well. The comprehensive index has a significant positive correlation with the gas production, and the prediction results are accurate.

Waste heat-driven water generator with optimized multi-cycle strategy for high water yield

Water scarcity and energy crisis have recently become two severe global problems. Low-grade waste heat, a substantial byproduct of energy consumption, promises to provide safe water by driving sorption-based atmospheric water harvesting (SAWH) device. Herein, a low-grade waste heat-driven atmospheric water generator (LWG) is constructed with rapid kinetics at the system level. Solely in 3 h, the device obtains 1.766 g g−1 of water productivity and up to 98 % of water recovery ratio driven by 120 °C of waste heat. Further, an optimized multi-cycle operation strategy is proposed to guide LWG's daily water harvesting, enabling it to predictably obtain over 15 kg m−2 day−1 water productivity by maximizing systemic sorption and desorption-condensation rates. The strategy not only is widely suitable for all SAWH devices, but also provides a universal optimization guideline for sorption-based dehumidification, thermal storage, and electric thermal management.

Design of MOF-Based Solar Evaporators with Hierarchical Microporous/Nanobridged/Nanogranular Structures for Rapid Interfacial Solar Evaporation and Fresh Water Collection.

Interfacial solar evaporation (ISE) holds considerable promise to solve fresh water shortage, but it is challenging to achieve high evaporation rate (Reva) and fresh water yield in close system. Here, we report design and preparation of MOF-based solar evaporators with hierarchical microporous/nanobridged/nanogranular structures for rapid ISE and fresh water collection in close system. The evaporators are fabricated by growing silicone nanofilaments with variable length as nanobridges on a microporous silicone sponge followed by grafting with polydopamine nanoparticles and Cu-MOF nanocrystals. Integration of the unique structure and excellent photothermal composites endows the evaporators with high Reva of 3.5-20 wt% brines (3.60-2.90 kg m-2 h-1 in open system and 2.38-1.44 kg m-2 h-1 in close system) under simulated 1 sun, high Reva under natural sunlight, excellent salt resistance and high fresh water yield, which surpass most state-of-the-art evaporators. Moreover, when combined with a superhydrophilic cover, the evaporators show much higher average Reva of real seawater, remarkable fresh water yield and excellent long-term stability over one month continuous ISE under natural sunlight. The findings here will promote the development of advanced evaporators via microstructure engineering and their real-world ISE applications.

Application Research of Integrated Geophysical Methods in Hydrogeological Survey in Extremely Arid Desert Areas

The research area is located in the Wuyi Mountain area of Dunhuang, Gansu Province, belonging to an extremely arid desert region. Previous hydrogeological surveys in the area had not conducted geophysical exploration work, and most of the hydrological boreholes previously drilled had either low water yield or almost no water yield. In this study, based on a comprehensive analysis of existing regional geological and hydrogeological data, the researchers conducted Controlled Source Audio-frequency Magnetotellurics (CSAMT) measurements and high-density electrical resistivity tomography (ERT) measurements. This work essentially identified the hydrogeological characteristics such as buried fracture water in the structural zones of the research area and water-rich properties. Hydrogeological boreholes were then deployed, and subsequent drilling confirmed a relatively high water yield.

One–Pot Three–Component Synthesis of 2,4,5–Triaryl Imidazoles using Fe3O4@BisImid−CuBr Nanocomposite as an Ecofriendly and Efficient Magnetically Reusable Catalyst

AbstractImidazoles are one of the keys of N‐heterocycle molecules that exist in the structure of many biomolecules. In this research project, we reported that Fe3O4@BisImid−CuBr nanocomposite is an attractive and efficient nanomagnetic catalyst to afford 2,4,5–triaryl imidazoles through reactions of 1,2–diketones and aldehydes in the presence of NH4OAc under ecofriendly conditions. The Fe3O4@BisImid−CuBr nanocomposite was readily fabricated by a simple method from available reagents and its structure was analyzed by spectroscopic techniques. SEM and TEM images affirmed the formation of particles in spherical shape and nanometer–size. Under this methodology, a diverse library of triaryl imidazoles were afforded with high yields in water. This synthetic methodology has significant features such as (a) high yields and high purity of the products (b) suitable reaction time (c) use of magnetic reusable nanocatalyst (d) high reusability of Fe3O4@BisImid−CuBr nanocatalyst and the performance of reactions in aqueous medium.

Large scale water yield assessment for sparsely monitored river basins: A case study for Afghanistan

This paper presents results from a study on water yield assessment across five major river basins of Afghanistan. The study was conducted using GR4J and GR4JSG precipitation-runoff models. The river basins were divided into 207 subcatchments and each subcatchment was divided into multiple functional units. The model was calibrated using observed streamflow data from 2008 to 2015 and validated over the 2016 to 2020 period. Model parameters were calibrated for an unregulated subcatchment in each basin and calibrated parameters from the best-performing subcatchment were transferred to other subcatchments. Results show that modelled water yield across the five basins varies from 0.3 mm in the Helmand basin to 248 mm in the Panj-Amu basin, with an average of 72.1 mm for the entire country. In the period of 2008 to 2020, area averaged water yield in the five basins varies from 36 to 174 mm. For the same period, mean annual precipitation for the entire country is 234.0 mm, indicating a water yield of 30.8%. The nation-wide average water yield of 72.1 mm is equivalent to 46.3 billion cubic meters (BCM) of surface water for the country. In addition, about 28.9 BCM generates annually in the neighbouring Tajikistan and Pakistan from snow and glaciers of the Hindu-Kush mountains. The elevated northern parts of Afghanistan, including parts of neighbouring Tajikistan are the primary water source. Water yield across the country varies between years but there is no consistent increasing or decreasing trends. About 60 to 70% of flow occurs between March to June. The study identified the high water yield areas and investigated variability at monthly, seasonal, and annual time scales. An importance finding is the large spatial and temporal variability of water yield across the basins. This information is crucial for long-term water resources planning and management for agricultural development.

Enhanced interfacial evaporation of CF@NC fabric via coupled photo-thermal and Joule-heating effect

To address the challenges of global water pollution and scarcity, solar-driven interfacial water evaporation has emerged as a viable method for producing clean water. Nevertheless, the efficacy of most extant interfacial evaporation systems were contingent upon abundant sunlight, thereby constraining their utility. To surmount the limitation, this study introduced a coupled tunable photo-thermal and Joule-heating process for interfacial evaporation utilizing carbon fiber (CF) modified by N-doped carbon nanotubes (NC). The CF@NC had highly graphitized structure, excellent light-absorbing ability and hydrophilicity, which made it suitable for photo-thermal and Joule-heating conversion. Under the coupled effect of photo-thermal and Joule-heating, the evaporation rate reached 10.37 kg·m−2·h−1 with 1 sun and 2.5 V, while the rate was 1.81 kg·m−2·h−1 under only 1 sun and 7.63 kg·m−2·h−1 with 2.5 V. Meanwhile, the CF@NC fabric evaporator also showed promising potential in salt tolerance and dye wastewater treatment. Under continuous all-day operation, a superior purification performance was achieved, which realized long periods of no salt operation and effectively remove the Rhodamine B and methyl orange in the water. Considering the high evaporation rate and reliable water yields obtained from simulated seawater and dye wastewater, the CF@NC fabric evaporator hold great promise for highly efficient purification.

Optimization of irrigation and fertilization of apples under magnetoelectric water irrigation in extremely arid areas.

Apple (Malus pumila Mill.) is one of the important economic crops in the arid areas of Xinjiang, China. For a long time, there has been a problem of high consumption but low yield in water and fertilizer management, prevent improvements in apple quality and yield. In this study, 5-year-old 'Royal Gala' apple trees in extremely arid areas of Xinjiang were used as experimental materials to carry out field experiments. considering 5 irrigation levels (W1, 30 mm; W2, 425 mm; W3, 550 mm; W4, 675 mm; W5, 800 mm) and 5 fertilization levels (F1, 280 kg·ha-1; F2, 360 kg·ha-1; F3, 440 kg·ha-1; F4, 520 kg·ha-1; F5, 600 kg·ha-1) under magnetoelectric water irrigation conditions. The results demonstrated that magnetoelectric water combined with the application of 675 mm irrigation amount and 520 kg·ha-1 fertilization amount was the most effective combination. These results occurred by increasing net photosynthetic rate of apple leaves, improved the quality of apples, increased apple yield, and promoted the improvement of water and fertilizer use efficiency. Additionally, the quadratic regression model was used to fit the response process of yield, IWUE and PFP to irrigation amount and fertilization amount, and the accuracy was greater than 0.8, indicating good fitting effects. The synergistic effect of water and fertilizer has a positive effect on optimizing apple water and fertilizer management. Principal component analysis showed that the magnetoelectric treatment combined water and fertilizer mainly affected apple yield, water and fertilizer use efficiency and vitamin C content related to quality. This study provides valuable guidance for improving water and fertilizer productivity, crop yield and quality in extreme arid areas of Xinjiang by using Magnetoelectric water irrigation.

Factor analysis of hydrologic services in water-controlled grassland ecosystems by InVEST model and geodetector.

Water conservation is highly important for a successful desert grassland ecosystem, but there was no comprehensive view on how to assess influencing factors in managing and addressing water yield and water conservation in desert steppe. The Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model, which is specifically used for the assessment of ecosystem services, was combined with geographic detectors to identify the priority areas for water conservation function and analyze the driving factors of water conservation in the Tabu River Basin, Inner Mongolia Autonomous Region, China, using different meteorological data sources. (i) The InVEST model has the advantage of modeling water yield and water conservation at spatial scales by fusion downscaling data. High water yield mainly occurs in the southern hilly mountainous areas, low water yield in the northern desert and grassland areas, and between the two in the central agro-pastoral areas; the multi-year average water conservation and water yield based on the InVEST model are 3.3 and 16mm, respectively. (ii) Water yield and water conservation roughly show a transitional phenomenon of "high in the south and low in the north." The water yield and water conservation per unit area of the Tabu River Basin are relatively large for construction land, unused land, and cropland, relatively small for grassland and forestland, and basically zero for water bodies. Forest land has the strongest water conservation capacity, followed by grassland and farmland, while the order of water yield capacity is the opposite. (iii) Precipitation shows the strongest explanatory power for water yield (q = 0.427), followed by land use types (q = 0.411). The precipitation ∩ actual evapotranspiration has the strongest explanatory power for water yield (q = 0.87). The explanatory power of water yield on water conservation is the strongest (q = 0.752), followed by precipitation (q = 0.4), and the water yield ∩ soil has the greatest explanatory power on water conservation (q = 0.91). These findings are crucial for promoting regional hydrologic services and can provide a water resources management strategy for decision-makers.

Highly efficient portable atmospheric water harvester with integrated structure design for high yield water production

Sorption-based atmospheric water harvesting (SAWH) as an appealing way to address global water shortage can obtain water from air anytime and anywhere. However, achieving liter-scale water yield by portable device for daily demand is still a challenge. Here, a 7.5-L portable atmospheric water harvester with optimized structure design was proposed. By adopting central heating and radiation heat shielding strategy to minimize heat losses during desorption process and utilizing a batch-process operation model, the device presented superior productivity of 1150 gwater/day with low energy consumption of 1.7 kWh/L under field test. This is the first demonstration to promote daily water yield of small-size SAWH device to an order of 1000 g with lower energy consumption compared with existing active SAWH studies. Optimized heat and mass transfer within compact structure enabled the water yield per unit volume and weight of the device reaching milestone values of 152.5 gwater/Ldevice/day and 199.4 gwater/kgdevice/day. This remarkable performance motivated the feasibility of distributed freshwater production and pushed SAWH technology one step closer to the practical applications.

Enantioselective Michael Addition of Cyclohexanone to Nitroolefins Catalyzed by a New Pyrrolidinyl-isosteviol Bifunctional Organocatalyst in Water

Abstract: A new pyrrolidinyl-isosteviol bifunctional organocatalyst was synthesized, which was applied to catalyze the asymmetric Michael addition between cyclohexanone and nitroolefins. With 10 mol % of the organocatalyst, the reaction proceeded in water in high yields (up to 99%) with excellent diastereoselectivities (anti/syn up to 98:2) and good enantioselectivities (up to 90% ee). The design of the proline-isosteviol conjugates as organocatalysts was based on the crucial role of proline in the formation of enamine. To sum up, a new pyrrolidinyl-isosteviol bifunctional organocatalyst was synthesized, which could effectively catalyze the C-C formation reaction between a number of nitroolefins and cyclohexanone.

Hydrological response to land use land cover and climate variability, and simulation of sediment export and water yield in the catchment Kotri Sindh Pakistan using Soil and Water Assessment tool model.

The water availability concerns have been increasing due to significant impacts of land use land cover change, and climate variability. In terms of developing countries, it is one of the biggest challenges to overcome and manage sustainability in the present and future. This study aims to evaluate the change in hydrological components and simulation of sediment yield and water yield on the large-scale basin of Kotri barrage with a change in runoff due to a change in land use land cover. This study has been done on the watershed as well as the sub-watershed level to have an accurate estimation and simulation by finding the response of hydrological components toward its natural and human-induced factors using the Soil and Water Assessment tool with high-resolution geospatial-temporal inputs over the Kotri catchment. The sediment and water yield were quantified using 42 years of simulation (1981-2022) on the sub-basin level, projected to land use land cover 1990, 2000, 2010, and 2022. The increase in deforestation, agriculture, and settlement areas resulted increase in sediment load in the catchment. The sub-basins 14, 11, 12, and 13, with a high elevation and slope and with less vegetation showed higher sediment load and water yield than the sub-basins with gentle slope and with high natural vegetation cover. The sub-basins 10, 4, and 1 showed high water yield availability compared to basins 2, 3, 5, 6, 7, 8, 9. This may be the result of vegetation differences. However, contained less sediment load than basins 14, 11, 12, and 13. The main objective was to quantify the significant changes affecting catchment and sub-catchment areas, to have a better understanding of the management plan regarding land use land cover. The simulated data was further projected to prediction using machine algorithms (autoregressive integrated moving average) model for precipitation prediction, and (seasonal autoregressive integrated moving average with exogenous factors) model to predict the sediment yield and water yield in the catchment to 2060.

Simulation of Winter Wheat Growth Dynamics and Optimization of Water and Nitrogen Application Systems Based on the Aquacrop Model

Winter wheat is the main grain crop in the Yellow River Basin, and optimizing water and nitrogen management can not only improve the yield, but also reduce water and fertilizer waste and environmental pollution. Using two years of winter wheat field trials, the Aquacrop model was calibrated and validated, and 36 different water and nitrogen application scenarios were simulated and analyzed. Among them, the field trials were divided into three N application levels, and three lower limits of water control. The results showed that: (1) the model has good applicability to simulate the growth process of winter wheat in the Yellow River Basin. (2) At a constant level of irrigation or nitrogen application, crop yield initially increased and subsequently decreased with the enhancement of either irrigation or nitrogen application. Finally, through response surface analysis of regression equations, the recommended irrigation volume was determined to be between 296 and 303 mm, and the fertilizer application rate was set between 229 and 261 kg/ha. At these levels, the PFP could achieve over 60% of its maximum. This research provides a theoretical basis for the water-saving, fertilizer-saving and high-yield water and fertilizer management system of winter wheat in the irrigated area of the Yellow River Basin.

Harvesting freshwater from atmospheric air using thermal energy storage enabled solar air heater

Fresh water resources are scarce worldwide, and prevailing water harvesting systems face limitations of nighttime operations, high regeneration temperature and limited water yield. To address such issues, a novel system that integrates thermal energy storage unit for harvesting fresh water from atmospheric air is built and experimentally investigated under the ambient conditions. The system includes 4.86 m2 both ends open evacuated tube collector solar air heater to produce high regeneration temperature. Additionally, it incorporates a standalone for water vapor condensation. The performance of the system is compared using two different solid desiccant materials based on energy, exergy, environmental and economic analyses. The system using silica gel harvests 3.75 L/day of fresh water at a cost of 0.13 $/L with water harvesting coefficient of 0.76, while from molecular sieve, 3.41 L/day was harvested at 0.15 $/L with water harvesting coefficient of 0.64. From silica gel, the system reported the maximum thermal, overall and exergy efficiencies of 62.22 %, 10.29 % and 2.31 %, respectively, while from molecular sieve it was 59.12 %, 9.53 % and 2.08 %, respectively. The reports of water sample confirm that the harvested water from both the desiccant materials is good and safe for domestic consumption.

Spatiotemporal Variation and Factors Influencing Water Yield Services in the Hengduan Mountains, China

Conducting a quantitative assessment of water yield in mountainous areas is crucial for the management, development, and sustainable utilization of water resources. The Hengduan Mountains Region (HDMR) is a significant water-supporting area characterized by complex topography and climate changes. To analyze the spatial and temporal variations of water yield in the HDMR from 2001 to 2020, we employed the InVEST model and examined the influencing factors in conjunction with the elevation gradient. Our results indicate that: (1) The water yield in the Hengduan Mountains decreases from southeast to northwest, with the southwestern and eastern regions having high water yield values, and the high-altitude areas in the northwestern part having low water yield values. (2) The water yield in the Hengduan Mountains exhibits a decreasing trend followed by an increasing trend from 2001 to 2020, with the lowest level in 2011 and higher levels in 2004, 2018, and 2020. (3) Pixel-based trend analysis demonstrates a decreasing trend in water yield in the central and western parts of the study area, while the eastern part shows an increasing trend. (4) The climatic components, particularly precipitation, predominantly influence the spatial and temporal variations of water yield in the Transverse Mountain region. In most areas, evapotranspiration and land surface temperature have a negative impact on water yield. (5) Water yield tends to decrease and then increase on the altitudinal gradient, with precipitation and actual evapotranspiration being the factors directly affecting water yield, and land surface temperature and the proportion of forested areas having a significant indirect effect on water yield. Our study provides a scientific basis for water resources management and sustainable development in the Hengduan Mountains.

Aqueous Phase Organocatalytic Multicomponent Green Synthesis of 2‐Amino‐4H‐Chromenes

AbstractAn efficient and green method for the synthesis of 4H‐chromenes via an organocatalytic three‐component one‐pot reaction between active methylene compound, aromatic aldehydes and resorcinol with high yields (upto 98 %) in water is reported. To the best of our knowledge, ours is the first report of study of MCR on resacetophenone for the synthesis of 2‐amino‐4H‐chromenes. The organo catalyst DMAP was recovered and reused for 6 times without substantial decrease in the yields, and the products were purified just by recrystallization from ethanol which avoids purification through column. This easy to handle method reduces the use of many hazardous catalysts and adverse reaction conditions and utilizes simple, readily accessible and recyclable catalyst. Single crystal X‐ray clearly confirms the structures of synthesized chromenes.