Freshwater Stress Research Articles

Physiological activities, transcriptomes and metabolomes of Pyropia yezoensis conchocelis unveil the roles of pyPGK, pyBCKDHA, and pyDLD in response to freshwater soaking

Freshwater soaking of the conchocelis is often used to reduce yellow spot, white spot, and mud red disease in Pyropia yezoensis. However, the understanding of physiological, transcriptomic, and metabolomic changes for the conchocelis under freshwater stress remains limited. Here, we comprehensively explored the dynamic changes of physiological activities, transcriptomes, and metabolomes of the conchocelis under three points of freshwater stress (0 h, 4 h, and 24 h) and one point of seawater recovery (R2h). We found that the content of photosynthetic pigments, soluble proteins, and photosynthesis performance significantly responded to freshwater stress. Metabolomic analysis identified a total of 24 metabolites, including 15 DAMs, suggesting the metabolites changes in the conchocelis in response to freshwater stress. Additionally, comparative transcriptome and metabolome analyses identified a black co-expression module that was strongly correlated with the DAMs. Furthermore, this module was predominantly enriched in carbohydrate and amino acid metabolism pathways. We found that PyDLD, PyPGK, and PyBCKDHA were key genes in hub-networks, which are potentially involved in changes of leucine, valine, isoleucine, lactate, and floridoside during freshwater stress. These findings reveal the genetic basis of the dynamic changes of physiological activities, transcriptome, and metabolome in the Py. yezoensis conchocelis during freshwater soaking for disease control.

Economics of Water Scarcity and Efficiency

Over the coming decades, global freshwater withdrawals are expected to grow, especially in low- and middle-income countries. Unless there are significant improvements in the efficiency of water use by economies, freshwater stress, crises, and scarcity will worsen. This paper explores further the economic relationship between water use efficiency and scarcity. Because growing scarcity of freshwater in many regions and countries is not adequately reflected in markets, there are often insufficient incentives for investment and innovation to improve the efficiency of water use. To explore further changes in water use efficiency across countries, we conduct a panel analysis of water productivity changes for 130 countries from 1995 to 2020. Countries with lower initial levels of water use efficiency tended to have higher water productivity growth, whereas more agriculturally dependent economies displayed lower improvements in water use efficiency. Better institutional quality and capacity for innovation may also increase water use efficiency. We discuss the implications of these results for improving water use productivity in economies, and in particular, the opportunities and challenges for improving water markets and trades to alleviate water scarcity. We conclude by identifying further areas of research.

Synergistic Effect Between 0D CQDs and 2D MXene to Enhance the Photothermal Conversion of Hydrogel Evaporators for Efficient Solar Water Evaporation, Photothermal Sensing and Electricity Generation.

Solar-powered interfacial water evaporation is a promising technique for alleviating freshwater stress. However, the evaporation performance of solar evaporators is still constrained by low photothermal conversion efficiency and high water evaporation enthalpy. Herein, 0D carbon quantum dots (CQDs) are combined with 2D MXene to serve as a hybrid photothermal material to enhance the light absorption and photothermal conversion ability, meanwhile sodium carboxymethyl cellulose (CMC)/polyacrylamide (PAM) hydrogels are used as a substrate material for water transport to reduce the enthalpy of water evaporation. The synergistic effect in 0D CQDs/2D MXene hybrid photothermal materials accelerate the carrier transfer, inducing efficient localized surface plasmon resonance (LSPR) effect. This results in the enhanced photothermal conversion efficiency. The integrated hydrogel evaporators demonstrate a high evaporation rate (1.93 and 2.86kgm-2h-1 under 1 and 2 sunlights, respectively) and low evaporation enthalpy (1485Jg-1). In addition, the hydrogel evaporators are applied for photothermal sensing and temperature difference power generation (TEG). The TEG device presents an efficient output power density (230.7mWm-2) under 1 sunlight. This work provides a feasible approach for regulating and controlling the evaporation performances of hydrogel evaporators, and gives a proof-of-concept for the design of multipurpose solar evaporation systems.

Water and Economic Growth in Developed and Developing Countries

Water withdrawals are expected to continue growing, further straining available freshwater resources for economies. This review focuses on two key relationships between water and economic growth for developed and developing countries. Rising freshwater withdrawals and stress are directly related to how our economies use water to develop and grow. There is also concern that increasing water scarcity will impact economic growth across countries and regions. Unless there is a marked improvement in the water intensity of countries, economic growth will be the most important driver of increasing water withdrawals and scarcity. Although analysis of the impact of freshwater stress on the growth of economies is inconclusive, there is mounting evidence of an impact at the river basin and sub-national level. Decoupling rising water use from growth will require major water management reforms. Two of them are discussed here: Ending excessive subsidization of irrigation and reallocating subsidies for water supply and sanitation to expand delivery in developing countries.

Evaluation of residual sodium carbonate (RSC) and sodium adsorption ratio (SAR) in fresh water and laundry grey water for irrigation usage

AbstractThe current study was carried out to assess the suitability of laundry grey water (LGW) for reuse in irrigation so that it can help in the reduction of freshwater stress in irrigation sector. To address this objective, concentration of sodium (Na+), calcium (Ca2+), magnesium (Mg2+), carbonate (CO32−), bicarbonate (HCO3−), and phosphate (PO43−) were tested in fresh water (FW) collected before laundry washing and LGW generated after laundry washing from different households. The suitability of LGW for irrigation purpose was determined by using water quality indices such as Sodium adsorption ratio (SAR) and Residual Sodium Carbonate (RSC). The SAR values of FW at the rural and urban area sites varied from 0.84 to 1.10 and 0.82 to 4.30 respectively and remained in the excellent category for irrigation purpose. The SAR values of LGW at the rural and urban sites varied from 10.06 to 13.01 and 6.26 to 9.68, respectively. In contrast to the SAR values of the LGW at rural site, which remained under good quality category, SAR values remained under excellent category for irrigation purpose at urban sites. RSC values of FW and LGW were below 3.97 showing low or medium hazards associated with it for irrigation.

Seasonal forecast-informed reservoir operation. Potential benefits for a water-stressed Mediterranean basin

The increased seasonal demand for water puts pressure on Mediterranean water resources, which are often exploited in a non-renewable way. Besides, climate change can alter hydroclimatic patterns and exaggerate freshwater stress. Flexible operation of existing water reservoirs is one of the most cost-effective ways to mitigate water-related stress by storing water when it is abundant and releasing it when droughts persist. In this context, hydroclimatic forecasts can be central in properly informing reservoir operation. Nevertheless, the link between forecast skill and forecast value is neither easily predictable nor necessarily positive. Each system requires specific forecasts according to its characteristics, and the skill of existing forecast systems does not necessarily translate into a significant gain in system performance. In this work, we develop downscaled seasonal forecasts of reservoir inflow for the Faneromeni irrigation dam on Crete island. We then quantify the value of these seasonal forecasts in informing the reservoir operations. While the current operation of this reservoir is based on the available storage at the beginning of the irrigation season, we investigate alternatives by using the Evolutionary Multi Objectives Direct Policy Search method, which allows the design of flexible rules to cope with the variability of the hydrologic conditions as well as to include forecast information for conditioning operational decisions. Under historical climate conditions, results demonstrate a notable enhancement in performance solely by implementing more flexible operating policies. Incorporating perfect forecasts results in an additional improvement of 4% on average throughout the period from 1993 to 2019. However, when using actual forecasts, this gain diminishes to 1%. These outcomes support the exploration of potential trade-off solutions that effectively balance the competing demands within the region.

Papillaephyllum, a new genus of angiosperm foliage from the Cenomanian of the Czech Republic

Angiosperm foliage Papillaephyllum labutae Čepičková et J. Kvaček, gen. et sp. nov. is described from the Cenomanian, Late Cretaceous of the Peruc-Korycany Formation in the Bohemian Cretaceous Basin, Czech Republic. Papillaephyllum labutae has been erected for rarely-found fossils with basal-angiosperm signs, characterized by serrate, sometimes double-serrate margins with rounded chloranthoid teeth, each bearing a papilla. Venation is semicraspedodromous to festooned-semicraspedodromous with reticulate tertiary venation. Its micromorphology is distinctive in having the entire abaxial cuticle covered by papillae. Papillae of the subsidiary cells often form as visible wreaths around the stomata. Stomata are latero-cyclocytic and stephanocytic-bicyclic.Well-pronounced and numerous papillae of the external epidermal surface are an indicator of possible fresh-water stress, identifying the taxon as possibly meso- to xerophytic. Based on macro- and micromorphological comparison with fossil and recent material, affinity of Papillaephyllum labutae with the family Chloranthaceae is highly probable.

Kinetics of the Water Release of Hygroscopic Acrylamide Gel Embedded in Calcium Chloride by Thermogravimetric Analysis

Poly (acrylamide) gel was synthesized by radical polymerization of acrylamide and N, N'-methylene-bisacrylamide in the presence of benzoyl peroxide and carbon nanotubes. The dry product was saturated with calcium chloride and prepared for water absorption and desorption. The kinetics of water desorption of poly (acrylamide) gel embedded with hygroscopic calcium chloride (DHG), was studied from thermograms data of thermogravimetric analysis (TGA). DHG captures vapor from the environment and releases it as fresh water; it can be used as the condenser to build atmospheric water generators (AWGs) to alleviate the freshwater stress rusting from innovative activities such as industrial, agricultural, rural, and defense endeavors. The kinetics parameters of the synthesized DHG showed that it absorbed environmental vapor at room temperature and released water below its boiling point (40 to 90 °C), temperatures achievable under sunlight via the photothermal effect.

Mapping center pivot irrigation systems in global arid regions using instance segmentation and analyzing their spatial relationship with freshwater resources

Ensuring freshwater availability and supply sufficient for socio-economic development is important for human health and productivity. Globally, increasing industrial agriculture is driving crop productivity, with increasing surface water and groundwater being withdrawn for irrigation. This study mapped center pivot irrigation systems (CPIS), which are indicators of intensified industrial agriculture and large-scale investment in agriculture, with satellite data using a convolutional neural network in global arid areas. A cascade instance segmentation network was adopted, and both the convolutional block attention module technique and PointRend technique were used to increase the performance of off-the-shelf algorithms. Geospatial analysis methods were used to derive the relationships between CPIS and freshwater resources. Overall there were about 10.26 million hectares (Mha) of irrigated areas equipped with CPIS in global arid areas in 2021, and there were 4.41 Mha of CPIS-equipped irrigated fields added in the past twenty years at a relative increase of 75% compared with those at the beginning of this century. Although the largest extent of increased CPIS-equipped irrigated fields was in North America, the other five continents had higher relative increases, with Africa having the highest relative growth of 253%. The analysis of spatial relationships between CPIS and freshwater resources indicates that the stress on freshwater resources from industrial agriculture is intensifying in arid areas globally. Overall, the world's arid regions with the highest water stress from CPIS are mostly located in western North America, northern Africa, and the Arabian Peninsula. The results facilitate a better understanding of the current status of freshwater stress and ecosystem sustainability in relation to the development of agricultural intensification in global arid areas. The outcomes support governments to judge better the environmental consequences of agricultural modernization and further help them make balanced agriculture and water management policies.

Advancing water footprint assessments: Combining the impacts of water pollution and scarcity

Several water footprint indicators have been developed to curb freshwater stress. Volumetric footprints support water allocation decisions and strive to increase water productivity in all sectors. In contrast, impact-oriented footprints are used to minimize the impacts of water use on human health, ecosystems, and freshwater resources. Efforts to combine both perspectives in a harmonized framework have been undertaken, but common challenges remain, such as pollution and ecosystems impacts modelling. To address these knowledge gaps, we build upon a water footprint assessment framework proposed at conceptual level to expand and operationalize relevant features. We propose two regionalized indicators, namely the water biodiversity footprint and the water resource footprint, that aggregate all impacts from toxic chemicals, nutrients, and water scarcity. The first impact indicator represents the impacts on freshwater ecosystems. The second one models the competition for freshwater resources and its consequences on freshwater availability. As part of the framework, we complement the two indicators with a sustainability assessment representing the levels above which ecological and human freshwater needs are no longer sustained. We test our approach assessing the sustainability of water use in the European Union in 2010. Water stress hampers 15 % of domestic, agricultural and industrial water demand, mainly due to irrigation and pesticide emissions in southern Europe. Moreover, damage to the freshwater ecosystems is widespread and mostly resulting from chemical emissions from industry. Approximately 5 % of the area is exceeding the regional sustainability limits for ecosystems and human water requirements altogether. Concerted efforts from all sectors are needed to reduce the impacts of emissions and water consumption under the sustainability limits. These advances are considered an important step toward the harmonization of volumetric and impact-oriented approaches to achieve consistent and holistic water footprinting as well as contributing to strengthen the policy relevance of water footprint assessments.

Stakeholder-based decision support model for selection of alternative water sources - A path towards sustainable industrial future in Vietnam

The combined effect of climate change, rapid industrialisation and traditional water use has created freshwater stress situations in industrial delta regions. Alternative Water Sources (AWSs) offer opportunities to mitigate the freshwater stress issue and, thus, contribute to a sustainable industrial future. This study developed a Decision Support Model (DSM) to assist the decision-makers in selecting the most feasible AWS. In the study location, Tan Thuan Export and Processing Zone (TTZ) of Ho Chi Minh City, rainwater, industrial effluent and brackish water were selected as AWS options and evaluated for technical, environmental, economic, social and institutional criteria. The stakeholder organisations representing government organisations, industrial-zone management organisations and enterprises were selected as decision-makers based on their willingness to explore AWSs. Four DSM scenarios were derived from the varying decision-making power of the selected stakeholder organisations. The results obtained from applying DSM in TTZ showed rainwater as the most feasible AWS for all the scenarios, while the rank of other AWSs fluctuated for different scenarios. To implement the result of DSM in practice, the government should not only focus on formulating clear technological guidelines on AWS quality but also on providing subsidies and creating an environment of social acceptance of AWSs. The DSM allows the decision-makers to determine the most capable AWS in mitigating freshwater stress issues and the changes required to shift towards these AWSs.

Carbon fiber supported Co/Co3O4-embedded N-doped carbon microparticles for efficient overall seawater splitting and oxygen reduction

Due to low cost and abundance, direct seawater splitting to produce hydrogen is an encouraging strategy to alleviate the consumption of fossil energy, while also avoiding freshwater stress. However, when natural seawater is utilized as the electrolyte, the catalysts on the cathode and anode of water splitting should not only have high activity to promote energy efficiency, but also have good stability and durability to resist the corrosion of chloride ions. Herein, a hierarchical carbon-based catalyst for hydrogen and oxygen evolution, ZIF-67/CF-1, was prepared by annealing a composite of ZIF-67 and carbon fiber (CF). It exhibits good electrocatalytic activity and stability for overall splitting in natural seawater and neutral PBS solution. Impressively, when an electrolyzer consisting of ZIF-67/CF-1||ZIF-67/CF-1 is applied to overall seawater splitting, the current density of 10 mA/cm2 is achieved with a drive voltage of 2.46 V, which is only 0.28 V higher than precious metal-based electrolyzer (Pt/C||IrO2). Meanwhile, ZIF-67/CF-1 shows outstanding catalytic ability for oxygen reduction (E1/2 = 0.84 V, Tafel slope = 66.9 mV/dec), also demonstrating its application potential in rechargeable batteries and fuel cells.

Energy-Saving Hydrogen Production by Seawater Electrolysis Coupling Sulfion Degradation.

Electrolysis of costless and infinite seawater is a promising way toward grid-scale hydrogen production without causing freshwater stress. Practical potential of this technology, however, is hindered by low energy efficiency and anode corrosion by the detrimental chlorine chemistry in seawater in addition to unaffordable electricity expense. Herein, energy-saving hydrogen production is reported by chlorine-free seawater splitting coupling sulfion oxidation. It yields hydrogen at a low cell voltage of 0.97V, cutting the electricity consumption to 2.32kWh per m3 H2 at 300mA cm-2 . Compared to alkaline water electrolysis, the energy expense is primarily saved by 60% with 50% lower energy equivalent input. Benefiting from the ultralow cell voltage, the hazardous chlorine chemistry is fully avoided without anode corrosion regardless of Cl- crossover. Meanwhile, it also allows fast degradation of S2- pollutant from the water body to value-added sulfur with 80% efficiency, for further reducing hydrogen cost and protection of the ecosystem. Connecting such a hybrid seawater electrolyzer to a commercial solar cell can harvest the hydrogen from seawater with better sustainability. This work may offer new opportunities for low-cost hydrogen production from the unlimited ocean resources with environmental protection.

Hotspots for social and ecological impacts from freshwater stress and storage loss

Humans and ecosystems are deeply connected to, and through, the hydrological cycle. However, impacts of hydrological change on social and ecological systems are infrequently evaluated together at the global scale. Here, we focus on the potential for social and ecological impacts from freshwater stress and storage loss. We find basins with existing freshwater stress are drying (losing storage) disproportionately, exacerbating the challenges facing the water stressed versus non-stressed basins of the world. We map the global gradient in social-ecological vulnerability to freshwater stress and storage loss and identify hotspot basins for prioritization (n = 168). These most-vulnerable basins encompass over 1.5 billion people, 17% of global food crop production, 13% of global gross domestic product, and hundreds of significant wetlands. There are thus substantial social and ecological benefits to reducing vulnerability in hotspot basins, which can be achieved through hydro-diplomacy, social adaptive capacity building, and integrated water resources management practices.

Estimating salinity stress via hsp70 expression in the invasive round goby (Neogobius melanostomus): implications for further range expansion

Species invasions often occur on coasts and estuaries where abiotic conditions vary, e.g. salinity, temperature, runoff etc. Successful establishment and dispersal of non-indigenous species in many such systems are poorly understood, partially since the species tend to show genetic and ecological plasticity at population level towards many abiotic conditions, including salinity tolerance. Plasticity may be driven by shifting expression of heat shock proteins such as Hsp70, which is widely recognized as indicator of physical stress. In this study, we developed a qPCR assay for expression of the hsp70 gene in the invasive round goby (Neogobius melanostomus) and tested the expression response of fish collected from a brackish environment in the western Baltic Sea to three different salinities, 0, 10 and 30. hsp70 expression was highest in fresh water, indicating higher stress, and lower at brackish (ambient condition for the sampled population) and oceanic salinities, suggestive of low stress response to salinities above the population’s current distribution. The highest stress in fresh water was surprising since populations in fresh water exist, e.g. large European rivers and Laurentian Great Lakes. The results have implications to predictions for the species’ plasticity potential and possible range expansion of the species into other salinity regimes.

Efficacy of mozuku fucoidan in alternative protein-based diet to improve growth, health performance, and stress resistance of juvenile red sea bream, Pagrus major.

We evaluated the efficacy of mozuku fucoidan supplementation to alternative dietary proteins used in fish meal (FM) replacement to enhance growth, immunity, and stress resistance of Pagrus major. Seven isonitrogenous (45% protein) experimental diets were formulated where diet 1 (D1) was FM-based control diet. Diets 2 to 7 were formulated by replacing 25, 50, and 75% of FM protein with soy protein isolate (SPI) protein, and each replacement level was supplemented without or with fucoidan at 0.4% for diet groups D2 (FM25), D3 (FM25Fu), D4 (FM50), D5 (FM50Fu), D6 (FM75), and D7(FM75Fu), respectively. Each diet was randomly allocated to triplicate groups of fish (4.1 g) for 56 days. Significantly higher weight gain and specific growth rate were observed in fish fed FM50Fu diet group, and it was not differed (P > 0.05) with fish fed FM25Fu diet group. FM-based control diet showed intermediate value, and it was not differed (P > 0.05) with or without fucoidan-supplemented ≤ 50% FM replacement groups and FM75Fu diet group. Significantly lower growth performances were observed in FM75 diet group. At each replacement level, fucoidan-supplemented groups showed nonsignificant improvement of feed utilization performances. Fish fed fucoidan-supplemented diets showed best condition of oxidative and freshwater stress resistance. Lysozyme activity, NBT, and peroxidase activity showed higher (P > 0.05)values in fucoidan-supplemented groups compared with the non-supplemented groups. Catalase activity was significantly lower in FM75Fu diet group. Catalase activity is significantly influenced by the interaction effects of fucoidan and FM replacement level. In conclusion, fucoidan supplementation could increase the efficiency of utilizing SPI (≥ 75%) without any adverse effects on red sea bream performance.

Influence of metal mesh wettability on fog harvesting in industrial cooling towers

Fresh water stress can be alleviated by harvesting water from the fog plumes of industrial cooling towers (CT) using metal meshes. A typical CT fog harvester contains inclined meshes that intercept the rising fog plume. Water droplets deposit on these meshes and then roll down the surfaces due to gravity into a collection manifold below the mesh. The amount of water collected depends on the fraction of fog that is intercepted by the meshes and how the deposited water droplets drain off to the collector. Both fog interception by a mesh and water drainage from it depend on the wettability of the mesh and its inclination with the vertical. Through surface treatments involving either wet chemical etching of stainless steel meshes or electrophoretic deposition of TiO2 nanoparticles on them, we alter mesh wettabilities, making them super-hydrophilic (SHPL), hydrophilic (HPL), or super-hydrophobic (SHPB). Then, fog harvesting efficacy is investigated by placing these meshes in a vertical fog tunnel that resembles a scaled-down configuration of fog collector inside the CT-cell. The drainage from an untreated control mesh and an SHPB mesh are comparable, while SHPL meshes produce poor drainage for small inclinations. Overall, TiO2-coated HPL meshes provide the best drainage which is maximum at a 15° mesh inclination angle.

Effect of land use and land cover changes on water quality in the Nawuni Catchment of the White Volta Basin, Northern Region, Ghana

Pollution of freshwater resources is gaining global attention due to increasing freshwater stress and scarcity. This study assessed land use and land cover changes (LULCC) in the Nawuni Catchment of the White Volta Basin and how the change affects water quality in the area. Satellite images from Landsat Thematic Mapper and Landsat 8 Operational land imager of the Nawuni Catchment of the White Volta Basin were acquired and used for this study. These images were analysed to ascertain the influence of land use and land cover changes on water quality parameters such as turbidity, ammonia and total coliform counts for a 10-year period (2007 to 2017). The results of LULCC revealed an increased expanse of grassland/farmland (4.1%), settlement (0.1%), bare land (9.4%) and closed savannah (1.2%), whilst opened savannah (14.7%) and water body (0.1%) recorded a decreasing trend. The study showed an increase in the levels of turbidity and ammonia and a decrease in total coliforms over the study period (2007 to 2017). The study also revealed a positive relationship between LULC categories and water quality parameters, implying that LULCC contribute to the change in water quality in the area. The study therefore recommends frequent water quality monitoring and LULC planning and management to curb pollution of the river basin.

Response of gut microbiota and immune function to hypoosmotic stress in the yellowfin seabream (Acanthopagrus latus)

Osmotic stress is associated with heightened immune functions and altered microbiota in the fish intestine. In this study, we explored the effects of hypoosmotic stress on the intestine of euryhaline yellowfin seabream (Acanthopagrus latus) after acute exposure to brackish water, low-saline water, and freshwater environments. The results showed that hypoosmotic stress reshaped the composition of the microbial community and altered the gene expression in the intestine. Probiotics Lactobacillus and Pseudomonas showed higher relative abundance in a brackish water environment, whereas pathogenic bacteria, including Vibrio and Aeromonas, were more abundant in the freshwater environment. At the transcriptional level, osmoregulation-related genes were identified as up/down regulated differentially expressed genes (DEGs) as well as a series of immune-related DEGs associated with pathogen recognition, antimicrobial ability, pro-inflammatory cytokines, cell apoptosis, and antioxidant defense. Physiological analysis showed that Na+ K+-ATPase activity was significantly inhibited by hypoosmotic stress in freshwater. Meanwhile, the intestinal antioxidant defense system of yellowfin seabream was challenged. Correlation network analysis demonstrated the close interactions among intestinal microbes, differentially expressed genes, and physiological parameters. This study provides the critical insights into the function of the intestine fish encountering hypoosmotic stress.

Identification of climate variables dominating streamflow generation and quantification of streamflow decline in the Loess Plateau, China

Precipitation-extremes-driven floods, which compose an important proportion of streamflow but cause severe adverse impacts in the Loess Plateau of China, urged the progressive implementation of ecological restoration (ER) strategies in the Loess Plateau (LP) of China. Knowledge of the linkage between climate variables (especially precipitation extremes) and streamflow generation become more essential for advanced catchment management as ER and climate variability have resulted in reduced streamflow and freshwater stress. Here, a partial least squares regression (PLSR) approach was used to investigate this issue at 16 main catchments of the LP over a reference period (1961–1979). Then, we quantified streamflow decline during the “Integrated Soil and Water Conservation” (1980–1999) and the “Grain for Grain” (2000–2015) strategies by PLSR modeling. We found that the dominant climatic variables controlling annual streamflow include heavy precipitation amount and heavy precipitation days, maximum precipitation event amount, number of consecutive wet days, annual total precipitation (daily precipitation ≥1 mm), and effective precipitation amount (daily precipitation ≥5 mm). Further, the effect of precipitation extremes on streamflow generation is stronger in drier catchments. The impacts of precipitation extremes on streamflow generation can be strengthened by agricultural cultivation and weakened by revegetation (especially reforestation). Overall, we found that climate-driven annual streamflow decreased by 7.5 mm during 1980–1999 and by 5.6 mm during 2000–2015, in comparison to 1961–1979. The dominant cause of streamflow reduction was ER, with the contribution increasing from 59% in 1980–1999 to 82% in 2000–2015. The PLSR approach enables the identification of linkages between climate variables and streamflow generation, and the prediction of climate-driven streamflow. This study yields a greater understanding of the influences of climate variability and ER on streamflow change, and is helpful to identify hydroclimatological trends and projections.