This study analyzes the effects of Hurricane Eta on the Chiriqui Viejo River basin, revealing the significant impact of extreme weather events on the hydrological dynamics of the region. The maximum rainfall recorded on November 4, 2020, reached 223.8 mm, while the flow in Paso Canoa reached 638.03 m3/s, demonstrating the magnitude of the event and the inability of the basin to handle such high volumes of water. Through a detailed analysis, it was observed that soil saturation resulted in direct runoff of up to 70.0 mm that same day, which shows that the infiltration capacity of the soil was quickly exceeded. Despite the damage observed, there are currently no advanced hydrological studies on extreme events in critical basins such as the Chiriqui Viejo River. This lack of research reflects a serious lack of planning and assessment of the risks associated with phenomena of this magnitude. One of the most critical problems found is the lack of specialized hydrology professionals, who are essential to carry out detailed studies and ensure sustainable management of water resources. In a context where climate change increases the frequency and intensity of extreme events, the absence of hydrologists in the region puts the resilience of the basin to future disasters at risk. The basin's hydraulic system demonstrated its inability to handle high flows, underscoring the need to improve flood control and water retention infrastructure. In addition, the lack of effective hydrological planning and coordination in the management of hydraulic infrastructures compromises both the safety of downstream communities and the sustainability of hydroelectric reservoirs, vital for the region.

Study region: Urumqi River headwater region in eastern Tianshan, central Asia. Study focus: Climate change is anticipated to accelerate glacier shrinkage and alter hydrological conditions, causing variations in the runoff patterns in the catchment and significantly threatening the regional water resources. However, few models exhibit adequate performance to simulate both surface alterations and glacier/snow runoff. Therefore, this study combined the glacier module with the Soil and Water Assessment Tool (SWAT) model to estimate the effect of climate change on the streamflow in the Urumqi River headwater region. The Urumqi River Headwater region is representative because of its long data series, viatal location, and local water availability, and it contains the longest-observed reference glacier (Urumqi Glacier No.1) in China, which spans the period from 1958 to the present. New hydrological insights for the region: The SWAT model performed satisfactorily for both calibration (1983-2005) and validation (2006-2016) periods with a Nash-Sutcliffe efficiency (NSE) greater than 0.80. The water balance analysis suggested that the snow/glacier melt contributed approximately 25% to the water yield. At the end of the 21st century, the temperature would increase by 2.4-3.8 degrees C while the precipitation would decrease by 1-2% under two future scenarios (ssp245 and ssp585). Thus, a 34-36% reduction in streamflow was projected due to above climate change impacts. This information would contribute to the development of adaptation strategies for sustainable water resource management.

In recent years, drought has become a global problem. Undoubtedly, drought monitoring is an important step for combating and reducing the resultant damage. Soil moisture, namely its spatial and temporal variability, is one of the most important environmental variables. Due to the difficulty cost, and timeliness of field measurements, this parameter has not been used widely in drought indexes. The recent development of global databases based on satellite imagery as well as rapid progress in hardware and software for modeling complex processes governing the water balance at the land surface employ these new tools to reduce the limitations in this field. The purpose of this research is to provide a comprehensive drought monitoring approach by integrating remote sensing data and the variable infiltration capacity (VIC) model with the Palmer Index (PDSI) in central Iran. In this study, the components of water and energy balance in the Central Iran region were simulated using the VIC land surface model. The output components of this model, especially soil moisture after evaluation, were used as inputs in the drought index based on Palmer's water balance. The integrated index of the VIC-PDSI in comparison with conventional Palmer indices and the SPI index at the 3, 6, 12, 24, and 48-month intervals was fitted with increments in moisture data and variations in the storage of water extracted from GRACE satellite data. Results showed that the combination of VIC-PDSI had the highest correlation coefficient of 0.87 with groundwater level change compared with other drought indices.

Evapotranspiration (ET) is an important water budget term for understanding the recovery of stormwater retention in green roof systems (GRs). However, ET evaluations, particularly in full-scale GRs, remain challenging. This study investigated ET dynamics within a GR in the City of Pittsburgh, USA, using a water balance based on continuously monitored soil moisture from moisture sensors over 15 months. Results suggest under well-watered soil conditions, daily moisture loss correlated with solar radiation, temperature, and humidity, in decreasing order of correlation strength, while wind speed had limited effects. Compared to sensor-informed moisture loss (using moisture-based water balance), the Hargreaves and FAO-56 Penman-Monteith equations predicted cumulative ET that was 1.8 and 2.1 times higher, respectively. When soil moisture declined and approached the temporary wilting points, a noticeable reduction in daily moisture loss was observed. This suggests the necessity of using a water stress coefficient alongside a crop coefficient to represent actual ET based on FAO-56 Penman-Monteith estimates. Seasonal crop coefficients from dominant native plant species present at our monitored location, eastern bluestar (Amsonia tabernaemontana) and creeping woodsorrel (Oxalis corniculata), had mean values of 0.48, 0.62, and 0.65 for fall, spring, and summer, respectively. The impact of water stress on ET could be characterized by a linear relationship with moisture content. Our results highlight the importance of soil moisture in regulating ET processes and demonstrate the utility of soil moisture data for evaluating ET in GRs and informing irrigation practices.

The occurrence of rainfall-induced slope failures has become more frequent due to the effect of climate change. Hence, various studies have been conducted to analyse the effect of rainfall infiltration on slope stability. Physically-based hydrological models have been commonly used with slope stability models such as the infinite slope model to develop slope susceptibility maps. However, a combination of three-dimensional (3D) water balance model with 3D limit equilibrium method (LEM) has not been commonly used. Hence, in this study, a water balance model, GEOtop was used to investigate the influence of subsurface flow in unsaturated soil under extreme rainfall conditions on regional slope stability in 3D directions. The results from the GEOtop model were used as inputs for 3D LEM slope stability analysis performed using the Scoops3D software to obtain the factor of safety (FOS) map for the region. Four slopes within the region were then selected to be modelled in the twodimensional (2D) seepage and slope stability analyses, SEEP/W and SLOPE/W. Results from the detailed study showed that the pore-water pressures (PWPs) from the 3D water balance analyses were found to be higher than the 2D seepage analyses. Under similar PWP conditions, the FOS from the 2D slope stability analysis was observed to be lower than the 3D analysis for two out of the four slopes. However, the combined 3D water balance and slope stability analyses produced lower FOS compared to the 2D seepage and slope stability analyses due to the higher PWPs in the 3D water balance analyses. Therefore, this study highlights the importance of considering the 3D subsurface flow in unsaturated soil given that it has a significant influence on the FOS of slopes.

Peatlands are major natural carbon pool in terrestrial ecosystems globally and are essential to a variety of fields, including global ecology, hydrology, and ecosystem services. Under the context of climate change, the management and conservation of peatlands has become a topic of international concern. Nevertheless, few studies have yet systematized the overall international dynamics of existing peatland research. In this study, based on an approach integrating bibliometrics and a literature review, we systematically analyzed peatland research from a literature perspective. Alongside traditional bibliometric analyses (e.g., number of publications, research impact, and hot areas), recent top keywords in peatland research were found, including 'oil palm', 'tropical peatland', 'permafrost', and so on. Furthermore, six hot topics of peatland research were identified: (1) peatland development and the impacts and degradations, (2) the history of peatland development and factors of formation, (3) chemical element contaminants in peatlands, (4) tropical peatlands, (5) peat adsorption and its humic acids, and (6) the influence of peatland conservation on the ecosystem. In addition, this review found that the adverse consequences of peatland degradation in the context of climate change merit greater attention, that peatland-mapping techniques suitable for all regions are lacking, that a unified global assessment of carbon stocks in peatlands urgently needs to be established, spanning all countries, and that a reliable system for assessing peatland-ecosystem services needs to be implemented expeditiously. In this study, we argued that enhanced integration in research will bridge knowledge gaps and facilitate the systematic synthesis of peatlands as complex systems, which is an imperative need.

For two Austrian regions (Amstetten South and P & ouml;llauer valley), climate data from the periods 1961-1990 and 1991-2020 were analyzed and scenarios for +2 degrees C and +3 degrees C global warming (global warming level) were calculated in order to find out which changes relevant to fruit growing can be expected due to global warming. The comparison of the periods 1961-1990 and 1991-2020 already showed relevant changes that will continue to intensify in both scenarios: higher temperatures and less severe frosts in winter, longer growing seasons and an earlier start to vegetation at all altitudes. Late frosts in spring are becoming less frequent, but due to the earlier start of vegetation at the same time, the risk of frost damage - especially in April - remains and may even increase in some areas. The higher temperatures lead to a reduction in the climatic water balance, particularly in summer and at lower altitudes; in dry years, heat and drought stress are to be expected. In the lower altitudes of the two regions, where extensive orchards have had their main distribution up to now, they will come under increasing pressure, particularly on soils with low water retention capacity. Due to warmer summers and winters and longer growing seasons, the climate that is favorable for many types of fruit is increasingly shifting to higher altitudes that were previously less suitable and less commonly used for fruit growing. The risks and uncertainties for fruit production will increase considerably if the temperature rises by +2 degrees C, and at +3 degrees C, traditional forms of cultivation could be at risk. Active climate protection that limits global warming to below +2 degrees C is therefore essential to ensure a future perspective for extensive fruit orchards in Austria.

In this study, climate data from the periods 1961-1990 and 1991-2020 as well as scenarios for +2 degrees C and +3 degrees C global warming (global warming level gwl) were analyzed to find out what changes relevant to fruit growing can be expected in the Lungau region due to global warming. A favorable development due to climate change is already evident in the altitude level be- tween 1000 and 1200 m, which is the most relevant for fruit growing, and this will continue assuming the gwl +2 degrees C scenario. The minimum temperatures in winter will rise by an average of 4.6 degrees C compared to 1961-90, which is why extreme winter frosts will no longer be a limiting factor for most types of fruit. The growing season will be on average 24 days longer than compared to 1961-90, which favors fruit ripening and also enables the cultivation of varieties with a longer development period. The slightly negative climatic water availability already observed in spring is increasing due to the temperatures in spring and summer being around 2 degrees C higher and can lead to heat and drought stress in trees in particularly dry years, which is why the choice of deep soils for fruit growing without additional irrigation is recommended in the future. In the gwl +2 degrees C scenario, the opportunities for extensive orchards in the region outweigh the risks. This opens up the potential for Lungau to develop into a new Mostviertel (author's note: traditional Austrian perry growing region). Although 5 days less with <-2 degrees C are to be expected in April compared to 1961-90, the risk of frost damage remains or may even increase due to the vegetation start being around 14 days earlier and the inner-alpine location, especially in April. The seemingly favourable developments in the region caused by global warming will intensify under the assumption of the +3 degrees C scenario, but at the same time a further increase in extreme events is to be expected, which will significantly relativise the opportunities caused by climate change. In this respect, such a scenario cannot be considered desirable from a regional fruit growing perspective either.

Study region: Upper Yellow River Basin (UYRB), China. Study focus: We provide a comprehensive overview of the changes in the natural social binary water cycle system in the UYRB from the perspectives of the atmosphere, hydrosphere, cryosphere, biosphere, and human society by summarizing previous research results. New hydrological insight for the region: Since the 1980s, the continuous temperature rise led to permafrost thawing, resulting in a decrease in runoff and an increase in groundwater in the UYRB. The ecological protection and high-quality development of human society continuously increase the demand for water resources. Especially the runoff of the river in the human gathering area has significantly decreased and there has been an overexploitation of groundwater, resulting in a serious shortage of water resources. The future water supply and demand situation in the UYRB will be more severe. However, the current understanding of the natural social binary water cycle in the Upper Yellow River Basin is still insufficient, which seriously limits the high-quality development of human society in the UYRB. Among them, some erroneous conclusions can even provide misleading information for policy-making and cause serious manpower and resources loss. Natural social binary water cycle is still in initial stage in the UYRB, that is reflected in a lot of contradictions and shortcomings in past research. We propose four feasible research directions to comprehensively promote hydrometeorological research, providing effective guidance for the formulation of high-quality development policies in the UYRB.

This paper addresses the nexus of climate change and variability, soil moisture and surface runoff over the Lake Baikal catchment. Water level and distribution of dissolved and suspended matter over Lake Baikal are strongly affected by river inflow during rain-driven floods. In this study, we evaluate river flow changes at 44 streamflow gauges as well as related precipitation, evaporation, potential evaporation and soil moisture obtained from the ERA5-Land dataset. Based on Sen's slope trend estimator, Mann-Kendall non-parametric test, and using dominance analysis, we estimated the influence of meteorological parameters on river flow during 1979-2019. We found a significant correlation between the precipitation elasticity of river flow and catchment characteristics. Half of the gauges in the eastern part of the Selenga River basin showed a significant decreasing trend of average and maximum river flow (up to -2.9%/year). No changes in the central volume date of flood flow have been found. The reduction in rainfall amount explains more than 60% of runoff decrease. A decrease in evaporation is observed in areas where precipitation decrease is higher than 0.8%/year. Catchments, where the precipitation trends are not as substantial, are associated with increasing evaporation as a result of the increasing potential evaporation. Negative precipitation trends are accompanied by negative trends of soil moisture. Finally, the study reveals the sensitivity of catchments with steep slopes located in humid areas to precipitation change.