Changes In Water Balance Components Research Articles

Investigating the projected changes in water balance components under climate change considering the effect of storage structures

ABSTRACT The objective of this study was the critical challenge of accurately predicting water balance components in the Upper Bhima River basin, which is also facing significant challenges due to climate change. A major challenge faced in water balance studies is inadequacy of existing hydrological models to account for the effects of storage structures. The study utilized the variable infiltration capacity–routing application for parallel computation of discharge hydrological model with a newly developed storage structure scheme to simulate water balance components for historical (1999–2010) and future (2019–2040) periods, with future climate forcing from 19 Coupled Model Intercomparison Project Phase 5 GCMs under Representative Concentration Pathway (RCP)4.5 and RCP8.5 scenarios. The performance of the model was evaluated against observed streamflow data and around 30% improvement is noticed for the Nash–Sutcliffe efficiency score. The results signify the adverse impacts of climate change in the region, particularly a significant decrease in monsoon precipitation which may intensify drought scenarios and affect monsoon-driven agriculture. Furthermore, the study emphasizes the high sensitivity of baseflow in the Upper Bhima River to climate alterations, indicating potential threats to biodiversity and river ecosystem health. This research offers indispensable findings crucial for future strategies concerning hydropower, flood management, and water resource management in the region.

Spatiotemporal variation of water balance components in Mashhad catchment, Iran: Investigating the impact of changes in climatic data and land use

Abstract The research aims to investigate the spatiotemporal changes of water balance components and distinguish the relative impacts of climatic data and land-use on groundwater level in northeastern Iran. This investigation employs the WetSpass-M model to estimate water balance and the Mann-Kendall test alongside Sen's slope estimator to evaluate trend. The study also assesses mean annual water balance components, considering diverse combinations of land-use and soil. The findings offer a hydrological insight, revealing that 14% of precipitation results in runoff, 29% of that recharging the aquifer; the remaining portion is lost through evapotranspiration. The trends in precipitation and simulated water components are not significant but a significant downward trend in groundwater is observed beyond a specific point in time. Based on this outcome, as well as the analysis of land-use changes, it was speculated that human activities in this fast-developing region might be implicated in the decline in groundwater levels. Analysis of water balance components in various soil and land-use combinations indicates that evapotranspiration exhibits greater variability within the land-cover class, while recharge is more influenced by soil texture. These findings enhance our understanding for identifying potential sites for artificial recharge and determining sustainable groundwater withdrawals based on spatiotemporal recharge patterns.

A study on hydrological responses of the Fuhe River Basin to combined effects of land use and climate change

Study regionThe Fuhe River Basin in Jiangxi Province, China. Study focusGlobal climate change and intensified human activities are making the hydrological processes at Fuhe River Basin experiencing dramatic changes. Although some studies have investigated their individual impacts on basin-scale water resources, their combined effects on hydrology have received little attention. In this study, future scenarios were constructed for three future periods, based on five global climate model outputs (GCMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6) and a dataset of future land use projections under three shared socioeconomic pathways and representative concentration pathways (SSP-RCPs). Then, the Soil and Water Assessment Tool (SWAT) model was used to assess the relative changes in water balance components and extreme flow frequency under these developed scenarios. Furthermore, the hydrological response assessment methodology was improved from the original multiscenario ensemble flow forecast (MESF) framework, which not only strengthens the connection between climate and land use input changes but also adds more assessment items. New hydrological insights for the regionThe flow at the outlet of Fuhe River Basin is expected to increase by approximately 27.1%− 30.2%, 24.7–39.0% and 35.5%− 43.5% in the 2030 s, 2060 s and 2090 s, respectively. Water availability will increase significantly in February, August and October and decrease in November and December. To the end of 21st century, surface runoff will have more than 100% increase. Future floods and droughts will be more frequent and severe under SSP5–8.5.

Changes in water balance components of river basins in the Slovak Republic and Ukraine

Changes in water balance components of river basins in the Slovak Republic and Ukraine

Water balance components and climate extremes over Brazil under 1.5°C and 2.0°C of global warming scenarios.

The online version contains supplementary material available at 10.1007/s10113-023-02042-1.

ЗМІНИ ВОДНО-БАЛАНСОВИХ СКЛАДОВИХ В МЕЖАХ ЛІВОБЕРЕЖЖЯ СЕРЕДНЬОГО ДНІПРА ЗА 1961-2020 рр.

The article examines the changes in water balance components within the left bank of the Middle Dnipro during two hydroclimatic periods, 1961-1990 and 1991-2020. The research also covered six key river basins on the left bank of the Middle Dnipro, including Psel, Sula, Vorskla, Trubizh, Supii, and Zolotonoshka. The examination of the modifications in the components of the water balance during the period of the climatic norm from 1961-1990 and the modern climatic period from 1991-2020 revealed a decrease in the average long-term values of precipitation in general by -7.3 mm, river runoff by -5.2 mm, and total evaporation by -2.1 mm. The amount of rain on the left bank of the Middle Dnipro was different in each river basin. In the Psel and Sula basins, there was a significant increase in precipitation, with a difference of 18.4 mm and +0.9 mm, respectively. In the Vorskla, Zolotonoshka, Trubizh and Supii basins, there was less rain by -2.2 to -51.7 mm. The opposite scenario was observed in the variation of total evaporation in the respective river basins. Thus, in the three largest river basins of the Psel, Sula and Vorskla, it increased from 5.6 to 26.7 mm, in all other basins the total evaporation decreased from -0.3 to -47.6 mm. But despite various changes in precipitation and total evaporation, there is a reduction in the volume of river runoff from -1.6 to -8.6 mm. The negative dynamics of river runoff indicators are attributed to negative cumulative values of precipitation and total evaporation. The main cause of these changes is the increase in the average annual air temperature across all studied basins by +1.2 °C, leading to an increase in climate aridity indicators within the left bank of the Middle Dnipro by +0.9 %. Similarly, there was a drop in the runoff coefficient by 0.9 %. In essence, changes in water balance components in the studied area result in more water volume from atmospheric precipitation going towards total evaporation, leading to a loss of the water volume that forms river runoff. This serves as a clear example of the influence of the global increase in air temperature on the reduction of water volume in rivers within the left bank of the Middle Dnipro.

Post-processing R tool for SWAT efficiently studying climate change impacts on hydrology, water quality, and crop growth

Soil and Water Assessment Tool (SWAT) is widely used for watershed-scale assessment of climate change impacts, but post-processing of model outputs is a tedious job. An R tool was developed in this study for batch processing of SWAT output results. A case study was then performed in the Double Mountain Fork Brazos watershed in the Texas Panhandle using an improved SWAT model with the R tool to evaluate the simulated future changes in water balance components, total nitrogen (TN) load, and crop growth over the watershed. The results showed that the average annual future surface runoff increased by 8.9–17.9 mm and 11.5–22.6 mm in the irrigated and dryland cotton areas, respectively. Similarly, future TN load in irrigated and dryland cotton areas increased by approximately 0.4–0.9 kg ha−1 and 1.9–2.4 kg ha−1. The yields of irrigated and dryland cotton increased by 91.1%–122.1% and 47.5%–84.0% under the future climate scenarios, respectively.

Projected Changes in Water Balance Components of 11 Large River Basins during the 21st Century and Their Uncertainties

Projected Changes in Water Balance Components of 11 Large River Basins during the 21st Century and Their Uncertainties

Water resources of the Desna river basin under future climate

AbstractClimate change impact on water resources has been observed in Ukraine since the end of the 20th century. For now, only large-scale climate impact studies cover Ukraine's territory, having low credibility for a specific catchment. This study aims to calculate future changes in river discharge, water flow components, and soil water within the Desna basin and evaluate vulnerability trends on this basis. The framework assembles the process-based SWAT (Soil and Water Assessment Tool) model and eight high-resolution regional climate models (RCMs) driven by RCP4.5 and RCP8.5 emission scenarios. The climate models are provided by the Euro-CORDEX initiative and based on three RCMs (RCA4, HIRHAM5, and RACMO22E) forced by five general circulation models (CNRM-CM5, EC-EARTH, IPSL-CM5A-MR, HadGEM2-ES, and MPI-ESM-LR). The results preferably show a moderate increase in the annual discharge until the end of the 21st century. The intra-annual changes of water balance components negatively affect the vegetation period because of higher dryness and temperature stress but reduce flood risk, diffuse pollution, and water erosion in the far future. In the river basin management plan, the highest attention should be paid to adaptive strategies in agriculture because of possible water deficit in the vegetation season under future climate scenarios.

Hydroclimatic analysis of rising water levels in the Great rift Valley Lakes of Kenya

Study RegionThe Great Rift Valley lakes of Kenya have recently experienced significant increases in their water levels, negatively impacting the local communities. This has provoked renewed concerns about the causations, with various geological, anthropogenic and hydro-climatic influences hypothesized as potential causes of the water level rises. Study FocusThis study analyses and documents water level fluctuations in Lakes Baringo, Bogoria, Nakuru, Solai, Elementaita and Naivasha. Hydrometeorological analyses are undertaken to understand potential causes and lake volume data is used to derive the “Integrated Catchment Response” (ICR), a magnitude which allows to relate changes in water balance components to signals observed in the lake volume changes. New Hydrological Insights for the RegionCompared to 1984−2009, the recent increases in lake areas range from 21 % for Lake Naivasha to an extraordinary 123 % for Lake Solai. Mean annual rainfall for 2010−2020 increased by up to 30 %. Actual evapotranspiration also increased, but to lesser extent compared to rainfall. The results illustrate that changes in catchment properties due to anthropogenic influences or changes in underground permeability are not necessary to explain the lake level rises. Based on the ICR only surprisingly minor changes in the water balance are necessary to explain the lake level rises, since an increase of only 0.4–2 % of mean annual effective rainfall leads to the observed phenomena.

Spatial distribution and long-term changes in water balance components in Croatia

Drought causes great damage to the economy and agriculture in Croatia. Therefore, it is important to gain a better insight into the spatial distribution of water balance components (precipitation (P), potential evapotranspiration (PET), actual evapotranspiration (ET), soil moisture content (S), runoff (RO), recharge (R), and soil moisture loss (L)) and their long-term changes in Croatia. Since measurements of the mentioned components in Croatia are very rare, the Palmer model has been applied to estimate them. The meteorological data from 82 stations have been used in the period 1981–2010. To determine the climate variations long-term trends in water balance components have been analyzed in the period 1901–2017. The PET and ET linear trends in the last decades show a faster growth than in the long-term trends, and the increase in PET (50–80 mm/decade) is significant in most of Croatia, except in the eastern part (27 mm/decade). The results of the mean annual PET and ET spatial distribution revealed that the maximum PET is estimated in the mid-Adriatic area of about 1500 mm, but the lack of precipitation caused the ET (about 700 mm) to be insignificantly different from the values in other parts of Croatia. The analyzed meteorological data from the period 1981–2010 indicated a higher air temperature and lower precipitation amount than in the reference climatic period of 1961–1990. This reduces the ET in areas with insufficient precipitation, i.e., on the Adriatic coast and in the eastern part of Croatia, where an increasing soil moisture deficit during the vegetation period can have a potentially negative effect on agricultural production.

Modeling dominant height using stand and water balance variables for loblolly pine in the Western Gulf, US

Site-index models based on dominant height and age are commonly accepted measures of site productivity in forest plantations. Therefore, reliable estimates of dominant height over time are critical, as they provide the foundations for site productivity estimates used in growth and yield models. Forest site productivity depends on the combination of many environmental factors, whereas tree height is only a general proxy indicator of these factors interacting over time, and as such, subject to large errors. Hence, selection of appropriate environmental variables along with field-based data is expected to result in more consistent estimates. Although previous studies have incorporated climatic variables into site-index models, there is still a lack of understanding among the forest research community with respect to the selection of suitable climatic variables. Models including climatic water balance components such as water-deficit and excess-water are scarce. These components are especially important to address the influence of drought on plant growth. The main objective of this study is to evaluate the change in dominant height estimates of forest stands with respect to changes in water balance components. High-resolution actual evapotranspiration (AET) and potential evapotranspiration (PET) were combined to determine water excess/deficit of sites. These were incorporated into a loblolly pine polymorphic site index model using a generalized algebraic difference approach and maximum likelihood calibration methods that accounted for long-term uncertainty in the results. Our model further improves the precision in dominant height estimates for loblolly pine in the southeast US.

Scenario Forecasting of Changes in Water Balance Components in the Ob–Irtysh Basin in the Context of Possible Climate Change

Four global climate scenarios of the family “Special Report on Emissions Scenarios” of the Intergovernmental Panel on Climate Change, which correspond to the specified scenarios of economic, technological, political, and demographic development of the human civilization were used to develop forecast versions of meteorological forcing data dynamics in the Ob–Irtysh basin in the XXI century. The obtained data were used to simulate the variants of possible changes in water balance components in this river basin up to mid-XXI century. The calculation technique is based on the use of land surface model SWAP and a generator of climate scenarios MAGICC/SCENGEN. The changes in the annual runoff of the Ob, governed by possible global climate change are compared with its natural variations caused by weather noise.

Water balance responses to land-use/land-cover changes in the Pra River Basin of Ghana, 1986–2025

The unfavorable effect of human disturbances in major river basins resulting in extensive variations in the ecosystem has necessitated this research within the Pra River Basin of Ghana. Knowledge about how individual land use influences water balance components will massively improve natural resources planning, management and sustainable development. Land use/cover change in the basin was evaluated by the assessment of six historical and one future land use/cover maps relating to the land use/cover stages in 1986, 2000, 2004, 2008, 2013, 2016 and 2025. The land use/cover maps were deployed to generate seven land use/cover scenarios relating to diverse states of land use/cover change in the basin which were then deployed to simulate the hydrological components. The Soil and Water Assessment Tool was deployed for hydrological simulation. The results revealed that there was a continuous increase in cropland, settlement and mining at the detriment of forest areas from 1986 to 2016, which is expected to continue into 2025. The variations in land use/land cover brought about increment of surface runoff (124.51%) and water yield (40.13%), and reduced baseflow (30.08%) and ET (13.248%). Conversely, the results showed a reduction in surface runoff and water yield during dry season and increased baseflow and evapotranspiration during wet season. These trends are expected to further increase in 2025. Moreover, settlement and mining are the major contributors to changes in water balance components. These results show how important control of land use/cover is in order to maintain water balance components to guarantee water accessibility for all generations.

Assessment of Changes in Water Balance Components under 1.5 °C and 2.0 °C Global Warming in Transitional Climate Basin by Multi-RCPs and Multi-GCMs Approach

The global warming of 1.5 °C and 2.0 °C proposed in the Paris Agreement has become the iconic threshold of climate change impact research. This study aims to assess the potential impact of 1.5 °C and 2.0 °C global warming on water balance components (WBC) in a transitional climate basin—Chaobai River Basin (CRB)—which is the main water supply source of Beijing. A semi-distributed hydrological model SWAT (Soil and Water Assessment Tool) was driven by climate projections from five General Circulation Models (GCMs) under three Representative Concentration Pathways (RCPs) to simulate the future WBC in CRB under the 1.5 °C and 2.0 °C global warming, respectively. The impacts on annual, monthly WBC were assessed and the uncertainty associated with GCMs and RCPs were analyzed quantitatively, based on the model results. Finally, spatial variation of WBC change trend and its possible cause were discussed. The analysis results indicate that all the annual WBC and water budget are projected to increase under both warming scenarios. Change trend of WBC shows significant seasonal and spatial inhomogeneity. The frequency of flood will increase in flood season, while the probability of drought in autumn and March is expected to rise. The uneven spatial distribution of change trend might be attributed to topography and land use. The comparison between two warming scenarios indicates that the increment of 0.5 °C could lead to the decrease in annual surface runoff, lateral flow, percolation, and the increase in annual precipitation and evapotranspiration (ET). Uncertainties of surface runoff, lateral flow, and percolation projections are greater than those of other components. The additional 0.5 °C global warming will lead to larger uncertainties of future temperature, precipitation, surface runoff, and ET assessment, but slightly smaller uncertainties of lateral flow and percolation assessment. GCMs are proved to be the main factors that are responsible for the impact uncertainty of the majority assessed components.

Modeling the changes in water balance components of the highly irrigated western part of Bangladesh

Abstract. The objectives of the present study were to explore the changes in the water balance components (WBCs) by co-utilizing the discrete wavelet transform (DWT) and different forms of the Mann–Kendall (MK) test and develop a wavelet denoise autoregressive integrated moving average (WD-ARIMA) model for forecasting the WBCs. The results revealed that most of the potential evapotranspiration (PET) trends (approximately 73 %) had a decreasing tendency from 1981–1982 to 2012–2013 in the western part of Bangladesh. However, most of the trends (approximately 82 %) were not statistically significant at a 5 % significance level. The actual evapotranspiration (AET), annual deficit, and annual surplus also exhibited a similar tendency. The rainfall and temperature exhibited increasing trends. However, the WBCs exhibited an inverse trend, which suggested that the PET changes associated with temperature changes could not explain the change in the WBCs. Moreover, the 8-year (D3) and 16-year (D4) periodic components were generally responsible for the trends found in the original WBC data for the study area. The actual data was affected by noise, which resulted in the ARIMA model exhibiting an unsatisfactory performance. Therefore, wavelet denoising of the WBC time series was conducted to improve the performance of the ARIMA model. The quality of the denoising time series data was ensured using relevant statistical analysis. The performance of the WD-ARIMA model was assessed using the Nash–Sutcliffe efficiency (NSE) coefficient and coefficient of determination (R2). The WD-ARIMA model exhibited very good performance, which clearly demonstrated the advantages of denoising the time series data for forecasting the WBCs. The validation results of the model revealed that the forecasted values were very close to actual values, with an acceptable mean percentage error. The residuals also followed a normal distribution. The performance and validation results indicated that models can be used for the short-term forecasting of WBCs. Further studies on different combinations of wavelet analysis are required to develop a superior model for the hydrological forecasting in the context of climate change. The findings of this study can be used to improve water resource management in the highly irrigated western part of Bangladesh.

Contrasting runoff trends between dry and wet parts of eastern Tibetan Plateau

As the “Asian Water Tower”, the Tibetan Plateau (TP) provides water resources for more than 1.4 billion people, but suffers from climatic and environmental changes, followed by the changes in water balance components. We used state-of-the-art satellite-based products to estimate spatial and temporal variations and trends in annual precipitation, evapotranspiration and total water storage change across eastern TP, which were then used to reconstruct an annual runoff variability series for 2003–2014. The basin-scale reconstructed streamflow variability matched well with gauge observations for five large rivers. Annual runoff increased strongly in dry part because of increases in precipitation, but decreased in wet part because of decreases in precipitation, aggravated by noticeable increases in evapotranspiration in the north of wet part. Although precipitation primarily governed temporal-spatial pattern of runoff, total water storage change contributed greatly to runoff variation in regions with wide-spread permanent snow/ice or permafrost. Our study indicates that the contrasting runoff trends between the dry and wet parts of eastern TP requires a change in water security strategy, and attention should be paid to the negative water resources impacts detected for southwestern part which has undergone vast glacier retreat and decreasing precipitation.

Effects of soil‐type datasets on regional terrestrial water cycle simulations under different climatic regimes

AbstractHydrological simulations play an important role in estimating terrestrial water budgets and monitoring extreme events such as floods. This study investigates how these simulations are affected by soil‐type datasets and characterizes how these effects vary with climate. We study the differences between two ensemble simulations in China with the Noah‐MP land surface model using two soil datasets from the Food and Agriculture Organization and Beijing Normal University. The differences in ensemble means are analyzed over a 10 year period from 2003 to 2012 with respect to estimated soil moisture, the partition of precipitation between evapotranspiration and runoff, and a flood magnitude index. Results show that the hydrological simulations using sandier soil types result in lower soil moisture, lower evapotranspiration, and higher subsurface runoff. Each of these effects varies uniquely with aridity. The changes in soil moisture decrease with increasing aridity, while the changes in water balance components (evapotranspiration and runoff) peak in the transitional zone between humid and arid regions. The flood magnitude, expressed as the maximum daily flow normalized by annual flow, is also substantially influenced by the input soil type. Soil types with more clay and less sand content yield significantly bigger floods, especially in arid regions.

Assessing Variation in Water Balance Components in Mountainous Inland River Basin Experiencing Climate Change

Quantification of the changes of water balance components is significant for water resource assessment and management. This paper employed the Soil and Water Assessment Tool (SWAT) model to estimate the water balance in a mountainous watershed in northwest China at different spatial scales over the past half century. The results showed that both Nash-Sutcliffe efficiency (NSE) and determination coefficient (R2) were over 0.90 for the calibration and validation periods. The water balance components presented rising trends at the watershed scale, and the total runoff increased by 30.5% during 1964 to 2013 period. Rising surface runoff and rising groundwater flow contributed 42.7% and 57.3% of the total rising runoff, respectively. The runoff coefficient was sensitive to increasing precipitation and was not significant to the increase of temperature. The alpine meadow was the main landscape which occupied 51.1% of the watershed and contributed 55.5% of the total runoff. Grass land, forest land, bare land, and glacier covered 14.2%, 18.8%, 15.4%, and 0.5% of the watershed and contributed 8.5%, 16.9%, 15.9%, and 3.2% of the total runoff, respectively. The elevation zone from 3500 to 4500 m occupied 66.5% of the watershed area, and contributed the majority of the total runoff (70.7%). The runoff coefficients in the elevation zone from 1637 to 2800 m, 2800 to 3500 m, 3500 to 4000 m, 4000 to 4500 m, and 4500 to 5062 m were 0.20, 0.27, 0.32, 0.43, and 0.78, respectively, which tend to be larger along with the elevation increase. The quantities and change trends of the water balance components at the watershed scale were calculated by the results of the sub-watersheds. Furthermore, we characterized the spatial distribution of quantities and changes in trends of water balance components at the sub-watershed scale analysis. This study provides some references for water resource management and planning in inland river basins.

Scenario prediction of changes in water balance components in the Lena Basin in the context of possible climate changes

The dynamics of meteorological elements in the Lena R. Basin is predicted for the XXI century under four IPCC global scenarios of SRES family, corresponding to specified scenarios of the economic, technological, political, and demographic development of the civilization. The obtained predictions are used to simulate variants of possible changes in water balance components in the Lena Basin up to the mid-XXI century. The calculation procedure is based on the use of land-surface model SWAP and a climate scenario generator MAGICC/SCENGEN.