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1
Vu, T. T., J. Kiesel, B. Guse e N. Fohrer. "Towards an improved understanding of hydrological change – linking hydrologic metrics and multiple change point tests". Journal of Water and Climate Change 10, n. 4 (16 novembre 2018): 743–58. http://dx.doi.org/10.2166/wcc.2018.068.
Testo completoAbstract (sommario):
Abstract Understanding the connections between climate, anthropogenic impacts, and hydrology is fundamental for assessing future climate change. However, a comprehensive methodology is lacking to understand significant changes in the discharge regime and their causes. We propose an approach that links change point tests with hydrologic metrics applied to two Vietnamese catchments where both climatic and anthropogenic changes are observed. The change points in discharge series are revealed by six widely used change point tests. Then, 171 hydrologic metrics are investigated to evaluate all possible hydrological changes that occurred between the pre- and post-change point period. The tests showed sufficient capabilities to detect hydrological changes caused by precipitation alterations and damming. Linking the change point tests to the hydrological metrics had three benefits: (1) the significance of each detected change point was evaluated, (2) we found which test responds to which hydrologic metric, and (3) we were able to disentangle the hydrological impacts of the climatic and anthropogenic changes. Due to its objectivity, the presented method can improve the interpretation of anthropogenic changes and climate change impacts on the hydrological system.
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Flint, Lorraine E., e Alicia Torregrosa. "Evaluating Hydrological Responses to Climate Change". Water 12, n. 6 (12 giugno 2020): 1691. http://dx.doi.org/10.3390/w12061691.
Testo completoAbstract (sommario):
This Special Issue of the journal Water, “The Evaluation of Hydrologic Response to Climate Change”, is intended to explore the various impacts of climate change on hydrology. Using a selection of approaches, including field observations and hydrological modeling; investigations, including changing habitats and influences on organisms; modeling of water supply and impacts on landscapes; and the response of varying components of the hydrological cycle, the Issue has published nine articles from multi-institution, often multicountry collaborations that assess these changes in locations around the world, including China, Korea, Russia, Pakistan, Cambodia, United Kingdom, and Brazil.
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Liu, Junfang, Baolin Xue, Yinglan A, Wenchao Sun e Qingchun Guo. "Water balance changes in response to climate change in the upper Hailar River Basin, China". Hydrology Research 51, n. 5 (7 luglio 2020): 1023–35. http://dx.doi.org/10.2166/nh.2020.032.
Testo completoAbstract (sommario):
Abstract Projected climate change will have a profound effect on the hydrological balance of river basins globally. Studying water balance modification under changing climate conditions is significant for future river basin management, especially in certain arid and semiarid areas. In this study, we evaluated water balance changes (1981–2011) in the upper Hailar River Basin on the Mongolian Plateau. To evaluate the hydrological resilience of the basin to climate change, we calculated two Budyko metrics, i.e. dynamic deviation (d) and elasticity (e). The absolute magnitude of d reflects the ability of a basin to resist the influence of climate change and maintain its stable ecological function, whereas parameter e is used to assess whether a basin is hydrologically elastic. Results revealed modification of the hydrological balance during the study period has manifested as a decreasing trend of runoff and runoff-precipitation ratio. Correspondingly, basin-averaged evapotranspiration has also shown a decreasing trend, attributable mainly to precipitation. Furthermore, the calculated elasticity (e = 8.03) suggests the basin has high hydrological resilience, which indicates the basin ecosystem may maintain its hydrological function to a certain extent under a changing climate. The results of this study could assist water resource management in the study area and the prediction of ecosystem response to future climate change.
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Schulze, R. E. "Impacts of global climate change in a hydrologically vulnerable region: challenges to South African hydrologists". Progress in Physical Geography: Earth and Environment 21, n. 1 (marzo 1997): 113–36. http://dx.doi.org/10.1177/030913339702100107.
Testo completoAbstract (sommario):
South Africa is already hydrologically vulnerable and this is likely to be exacerbated by both nonpermanent ENSO-related as well as more permanently greenhouse-gas forced climate changes. Climate change effects are explained by way of the hydrological equation. This serves as a backdrop to a brief review, in a hydrological context, of projected perturbations to temperature, rainfall and potential evaporation, over southern Africa. Methodologies for simulating hydro logical responses to climate change are assessed. These include more direct GCM-derived output, with some emphasis on recent advances in climatic downscaling, and the application of appro priate hydrological models for use in impact studies. Scale problems of importance to hydrologists are highlighted. Directions to which climate change-related hydrological research efforts should be expended in South Africa are summarized, before two case study simulations, one a general sensitivity study of hydrological responses to changes in rainfall over southern Africa, the other a more specific hydrological response study to the El Niño of the 1982-83 season, are presented. The article concludes with a discussion on whether or not water resources practitioners in South Africa should respond to climate change.
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Liu, S., L. Tan, X. Mo e S. Zhang. "The need of the change of the conceptualisation of hydrologic processes under extreme conditions – taking reference evapotranspiration as an example". Proceedings of the International Association of Hydrological Sciences 371 (12 giugno 2015): 167–72. http://dx.doi.org/10.5194/piahs-371-167-2015.
Testo completoAbstract (sommario):
Abstract. What a hydrological model displays is the relationships between the output and input in daily, monthly, yearly and other temporal scales. In the case of climate change or other environment changes, the input of the hydrological model may show a gradual or abrupt change. There have been numerous documented studies to explore the response of output of the hydrological models to the change of the input with scenario simulation. Most of the studies assumed that the conceptualisation of hydrologic processes will remain, which may be true for the gradual change of the input. However, under extreme conditions the conceptualisation of hydrologic processes may be completely changed. Taking an example of the Allen's formula to calculate crop reference evapotranspiration (ET0) as a simple hydrological model, we analyze the alternation of the extreme in ET0 from 1955 to 2012 at the Chongling Experimental Station located in Hebei Province, China. The relationships between ET0 and the meteorological factors for the average values, minimum (maximum) values at daily, monthly and annual scales are revealed. It is found the extreme of the output can follow the extreme of the input better when their relationship is more linear. For non-liner relationship, the extreme of the input cannot at all be reflected from the extreme of the output. Relatively, extreme event at daily scale is harder to be shown than that at monthly scale. The result implicates that a routine model may not be able to catch the response to extreme events and it is even more so as we extrapolate models to higher temperature/CO2 conditions in the future. Some possible choices for the improvements are suggested for predicting hydrological extremes.
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Wang, Sen, Xia Liu, Xiayu Wang e Wenhao Jia. "Measuring hydrologic regime alterations and hydrodynamic characteristics in the Xijiang River Basin by the IHA-RVA method". Journal of Physics: Conference Series 2865, n. 1 (1 ottobre 2024): 012003. http://dx.doi.org/10.1088/1742-6596/2865/1/012003.
Testo completoAbstract (sommario):
Abstract An objective assessment of hydrological alterations is crucial for comprehensive water resource management, environmental protection, river ecosystem restoration, and integrated watershed water resource management. To quantitatively assess the ecological hydrologic regime alterations in the Xijiang River Basin in southern China considering the impacts from Longtan Reservoir, daily runoff data from two hydrological stations, Dahuangjiangkou and Wuzhou, are selected from 1973 to 2020. The changes in the flow are analyzed, and the indicators of hydrological alternation/range of variability approach (IHA-RVA) are employed to assess the hydrological regime alternations in the studied basin. The main findings are as follows: (1) Both stations show a decreasing trend in annual runoff, with the moving T-test detecting a change point in the runoff series in 2002. (2) The two stations’ overall hydrologic alteration degrees are 57% and 60%, with a more remarkable variation in the upstream area. Hydrological station changes tend to wane as the distance from the reservoir increases, which indicates that with the increased reservoir-station distance, the impact of the reservoir on the hydrologic process diminishes.
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Yang, Yiyang, Siyu Cai, Hao Wang, Ping Wang e Wei Li. "Evolution of Hydrological Conditions and Driving Factors Analysis of the Yongding River in a Changing Environment: A Case Study of the Xiangshuipu Section". Agronomy 13, n. 9 (30 agosto 2023): 2289. http://dx.doi.org/10.3390/agronomy13092289.
Testo completoAbstract (sommario):
Hydrological conditions are key factors in the evaluation of water resources and ecosystems. The Yongding River Basin has many irrigated areas, and excessive agricultural water consumption has led to serious water shortages and ecosystem damage. To investigate the evolution of ecohydrological conditions and their driving factors in the Yongding River basin in a changing environment, this study combines indicators of hydrologic alteration with the range of variability approach (IHA-RVA) to identify the most ecologically relevant hydrological indicators (ERHIs) and to determine the periods of hydrological variability in the basin, using the Xiangshuipu section on the Yang River as the study area. By calculating the degree of hydrological alteration, the evolutionary pattern of ecohydrological conditions in the basin was analyzed, and the WetSpa model was used to quantitatively identify the contributions of climate change, reservoir storage, and irrigation water withdrawal to the alteration of hydrological conditions. The results showed that the rise and fall rate; maximum and minimum 1 day flows; dates of maximum flow; and July flows were the most ecologically relevant hydrological indicators for the Xiangshuipu section. Variability of this section occurred between 1982 and 1988; except for the annual maximum 1 day flows and fall rate, which underwent moderate changes; all other indicators exhibited small changes and the overall hydrological alteration of the Xiangshuipu section was low. The most influential change in the hydrological conditions was irrigation water withdrawal (from specific irrigation); followed by climate change and reservoir storage. The results of this study provide an important basis for water resources utilization and ecological management in the Yongding River basin.
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Lestari, Isnayulia, e Bambang Dwi Dasanto. "Determination of Extreme Hydrological Index using HBV Model Simulation Results (Case Study : Upper Ciliwung Watershed)". Agromet 33, n. 1 (11 giugno 2019): 20–29. http://dx.doi.org/10.29244/j.agromet.33.1.20-29.
Testo completoAbstract (sommario):
The study of climate change on hydrological response is a crucial as climate change impact will drive the change in hydrological regimes of river. Upper Ciliwung watershed is one of the critical rivers in Java Island, which has been affected by climate change. This study aims to: (i) simulate the discharge flow using the Hydrologiska Byrans Vattenbalansavdelning (HBV) model; (ii) simulate future flow using three general circulation models (GCM) namely Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mk.3.6.0, Model for Interdisciplinary Research on Climate version 5 (MIROC5), and Geophysical Fluid Dynamics Laboratory-Coupled Model generation 3 (GFDL-CM3); (iii) determine the changes of extreme hydrological index during historical period (2001-2015) and projected period (2031-2045). The historical year simulation and projections are used to determine eight hydrologic extreme indices for high flow and low flow. We calibrated the HBV model for two years (2001-2002) and validated it for two years (2003-2004). Our model performed well in discharge simulation as shown by the NSE values (0.66 for calibration and validation). Then we calculated the indices for each period used (historical and projected). To show the changes in hydrological regimes, we compare the indices between two periods. Changes in the index of the two periods tend to decrease in value on the index parameters that characterize the minimum extreme events. Hence, that it is possible in the projected period there will be extreme hydrological events in the form of drought.
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Chevuturi, Amulya, Nicholas P. Klingaman, Andrew G. Turner, Liang Guo e Pier Luigi Vidale. "Projected Changes in the East Asian Hydrological Cycle for Different Levels of Future Global Warming". Atmosphere 13, n. 3 (1 marzo 2022): 405. http://dx.doi.org/10.3390/atmos13030405.
Testo completoAbstract (sommario):
Recent decades have shown significant changes to the hydrological cycle over East Asia (EA), and further changes are expected due to future global warming. This study evaluates projected seasonal changes in the EA hydrological cycle using simulations that are 1.5 °C, 2.0 °C and 3.0 ∘C warmer than pre-industrial, from the Met Office Unified Model (MetUM) Global Ocean Mixed Layer model version 2.0 (GOML2.0), compared against present-day conditions. The moisture sources of the warming-induced precipitation changes are identified over five hydrologically unique regions within EA. Precipitation over EA increases with warming (except over southeastern EA in the spring and autumn) due to the intensified hydrological cycle. The projected seasonal changes in the hydrological cycle are usually nonlinear, with the rate of change between 1.5 ∘C and 2.0 ∘C larger than the rate of change between 2.0 ∘C and 3.0 ∘C of warming. The warming-induced precipitation increases are mainly associated with an increase in remote moisture convergence rather than local moisture recycling, except over the Tibetan Plateau. Decomposition of the changes in moisture sources by direction and flux component indicate that changes from the west are dominated by changes to moisture and changes from the north are more circulation driven. The changes from the south are moisture driven over southern EA and driven by moisture and circulation change over northern EA. Our results highlight the regionally and seasonally diverse projected changes to the EA hydrological cycle due to global warming, which will be useful for region-specific climate mitigation policies and the implementation of seasonally varying adaptation methods.
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Visser-Quinn, Annie, Lindsay Beevers e Sandhya Patidar. "Replication of ecologically relevant hydrological indicators following a modified covariance approach to hydrological model parameterization". Hydrology and Earth System Sciences 23, n. 8 (9 agosto 2019): 3279–303. http://dx.doi.org/10.5194/hess-23-3279-2019.
Testo completoAbstract (sommario):
Abstract. Hydrological models can be used to assess the impact of hydrologic alteration on the river ecosystem. However, there are considerable limitations and uncertainties associated with the replication of ecologically relevant hydrological indicators. Vogel and Sankarasubramanian's 2003 (Water Resources Research) covariance approach to model evaluation and parameterization represents a shift away from algorithmic model calibration with traditional performance measures (objective functions). Using the covariance structures of the observed input and simulated output time series, it is possible to assess whether the selected hydrological model is able to capture the relevant underlying processes. From this plausible parameter space, the region of parameter space which best captures (replicates) the characteristics of a hydrological indicator may be identified. In this study, a modified covariance approach is applied to five hydrologically diverse case study catchments with a view to replicating a suite of ecologically relevant hydrological indicators identified through catchment-specific hydroecological models. The identification of the plausible parameter space (here n≈20) is based on the statistical importance of these indicators. Evaluation is with respect to performance and consistency across each catchment, parameter set, and the 40 ecologically relevant hydrological indicators considered. Timing and rate of change indicators are the best and worst replicated respectively. Relative to previous studies, an overall improvement in consistency is observed. This study represents an important advancement towards the robust application of hydrological models for ecological flow studies.
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Kim, Deasik, Hyunuk An, Minwon Jang e Seongjoon Kim. "Development of a distributed hydrological model considering hydrological change". Korean Journal of Agricultural Science 45, n. 3 (1 settembre 2018): 521–32. http://dx.doi.org/10.7744/kjoas.20180040.
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Banjara, Mandip, Amrit Bhusal, Amrit Babu Ghimire e Ajay Kalra. "Impact of Land Use and Land Cover Change on Hydrological Processes in Urban Watersheds: Analysis and Forecasting for Flood Risk Management". Geosciences 14, n. 2 (2 febbraio 2024): 40. http://dx.doi.org/10.3390/geosciences14020040.
Testo completoAbstract (sommario):
Land use and land cover (LULC) change is one of the primary contributors to hydrological change in urban watersheds and can potentially influence stream flow and flood volume. Understanding the impacts of LULC change on urban hydrological processes is critical to effective urban water management and minimizing flood risks. In this context, this study aims to determine the impacts of LULC change on hydrological response in a fast transitioning watershed for the predicted years of 2050 and 2080. This research employs the hybrid land use classification technique, Cellular Automata–Markov (CA–Markov) model to predict land use changes, utilizing land use data from 2001, 2013, and 2021. Additionally, it incorporates a calibrated, event-specific hydrologic model known as the Personal Computer Storm Water Management Model (PCSWMM) to assess alterations in hydrological responses for storm events of various magnitudes. The findings indicate a transition of the watershed into an urbanized landscape, replacing the previous dominance of agriculture and forested areas. The initial urban area, constituting 11.6% of the total area in 2021, expands to cover 34.1% and 44.2% of the total area by 2050 and 2080, respectively. Due to the LULC changes, there are increases in peak discharge of 5% and 6.8% and in runoff volume of 8% and 13.3% for the years 2050 and 2080 for a 100-year return period storm event. Yet, the extent of these changes intensifies notably during storm events with lower return periods. This heightened impact is directly attributed to the swift urbanization of the watershed. These results underscore the pressing necessity to regulate LULC change to preserve the hydrological equilibrium.
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Yao, C., L. Chang, J. Ding, Z. Li, D. An e Y. Zhang. "Evaluation of the effects of underlying surface change on catchment hydrological response using the HEC-HMS model". Proceedings of the International Association of Hydrological Sciences 364 (16 settembre 2014): 145–50. http://dx.doi.org/10.5194/piahs-364-145-2014.
Testo completoAbstract (sommario):
Abstract. Due to rapid population growth, China, and urbanization, the Dongwan catchment, with a drainage area of 2856 km2 and located in Henan Province, has been subjected to considerable land-use changes since the 1990s. Distributed or semi-distributed models have been widely used in catchment hydrological modeling, along with the rapid development of computer and GIS technologies. The objective of this study is to assess the impact of underlying surface change on catchment hydrological response using the Hydrologic Engineering Center's Hydrologic Modeling System (HEC-HMS), which is a distributed hydrological model. Specifically, 21 flood events were selected for calibrating and validating the model parameters. The satisfactory results show that the HEC-HMS model can be used to simulate the rainfall–runoff response in the Dongwan catchment. In light of the analyses of simulation results, it is shown that the flood peaks and runoff yields after 1990 moderately decrease in comparison with that before 1990 at the same precipitation level. It is also indicated that the underlying surface change leads to the increased flood storage capacity after 1990 in this region.
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Faye, Cheikh. "Rainfall and Discharge Variability in the Senegal River Basin Based on the IHA/RVA". Indonesian Journal of Social and Environmental Issues (IJSEI) 4, n. 1 (30 aprile 2023): 100–116. http://dx.doi.org/10.47540/ijsei.v4i1.711.
Testo completoAbstract (sommario):
The hydrological regime of a river is a driving force of its ecosystem. The operation of dams and locks has significant impacts on the hydrological situation of rivers. The objective of this study was to study the change and variability of precipitation and hydrological data in the Senegal River basin and to assess the change in the discharge regime of the Senegal River caused by the operation of the Manantali hydroelectric dam. Based on the IHA (Indicators of Hydrologic Alteration), a range of variability of thirty-three hydrological parameters was calculated and the hydrological alteration associated with the functioning of the dam was quantified. Using the RVA (Range of Variability Approach) method, the hydrological alteration at the Bakel site was evaluated and showed the influence of the dam on the hydrological state. The results showed a strong influence of the dam on the hydrological regime. The fluvial eco-hydrological objectives calculated in this study can constitute certain support for the management of water resources and ecosystems of the Senegal River basin.
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Chen, Yaning, Weihong Li, Gonghuan Fang e Zhi Li. "Review article: Hydrological modeling in glacierized catchments of central Asia – status and challenges". Hydrology and Earth System Sciences 21, n. 2 (2 febbraio 2017): 669–84. http://dx.doi.org/10.5194/hess-21-669-2017.
Testo completoAbstract (sommario):
Abstract. Meltwater from glacierized catchments is one of the most important water supplies in central Asia. Therefore, the effects of climate change on glaciers and snow cover will have increasingly significant consequences for runoff. Hydrological modeling has become an indispensable research approach to water resources management in large glacierized river basins, but there is a lack of focus in the modeling of glacial discharge. This paper reviews the status of hydrological modeling in glacierized catchments of central Asia, discussing the limitations of the available models and extrapolating these to future challenges and directions. After reviewing recent efforts, we conclude that the main sources of uncertainty in assessing the regional hydrological impacts of climate change are the unreliable and incomplete data sets and the lack of understanding of the hydrological regimes of glacierized catchments of central Asia. Runoff trends indicate a complex response to changes in climate. For future variation of water resources, it is essential to quantify the responses of hydrologic processes to both climate change and shrinking glaciers in glacierized catchments, and scientific focus should be on reducing uncertainties linked to these processes.
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Leta, Megersa Kebede, Tamene Adugna Demissie e Jens Tränckner. "Hydrological Responses of Watershed to Historical and Future Land Use Land Cover Change Dynamics of Nashe Watershed, Ethiopia". Water 13, n. 17 (29 agosto 2021): 2372. http://dx.doi.org/10.3390/w13172372.
Testo completoAbstract (sommario):
Land use land cover (LULC) change is the crucial driving force that affects the hydrological processes of a watershed. The changes of LULC have an important influence and are the main factor for monitoring the water balances. The assessment of LULC change is indispensable for sustainable development of land and water resources. Understanding the watershed responses to environmental changes and impacts of LULC classes on hydrological components is vigorous for planning water resources, land resource utilization, and hydrological balance sustaining. In this study, LULC effects on hydrological parameters of the Nashe watershed, Blue Nile River Basin are investigated. For this, historical and future LULC change scenarios in the Nashe watershed are implemented into a calibrated Soil and Water Assessment Tool (SWAT) model. Five LULC scenarios have been developed that represent baseline, current, and future periods corresponding to the map of 1990, 2005, 2019, 2035, and 2050. The predicted increase of agricultural and urban land by decreasing mainly forest land will lead till 2035 to an increase of 2.33% in surface runoff and a decline in ground water flow, lateral flow, and evapotranspiration. Between 2035 and 2050, a gradual increase of grass land and range land could mitigate the undesired tendency. The applied combination of LULC prognosis with process-based hydrologic modeling provide valuable data about the current and future understanding of variation in hydrological parameters and assist concerned bodies to improve land and water management in formulating approaches to minimize the conceivable increment of surface runoff.
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Burt, T. P. "Monitoring change in hydrological systems". Science of The Total Environment 310, n. 1-3 (luglio 2003): 9–16. http://dx.doi.org/10.1016/s0048-9697(02)00618-6.
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Huang, Yinghou, Binbin Huang, Tianling Qin, Hanjiang Nie, Jianwei Wang, Xing Li e Zhenqian Shen. "Assessment of Hydrological Changes and Their Influence on the Aquatic Ecology over the last 58 Years in Ganjiang Basin, China". Sustainability 11, n. 18 (6 settembre 2019): 4882. http://dx.doi.org/10.3390/su11184882.
Testo completoAbstract (sommario):
Runoff is the key driving factor of the Ganjiang River ecosystem. Human activities such as reservoir construction have greatly changed the state of runoff. In order to analyze the influence of Ganjiang Reservoir on the hydrological regime, the following paper is based on the daily precipitation data of 53 rainfall stations in Ganjiang River Basin from 1959 to 2016, and the daily runoff data of three stations in Dongbei, Ji’an, and Waizhou from 1959 to 2016. The Mann–Kendall test (MK) was used to analyze the trend of precipitation and runoff in Ganjiang River Basin. The Sliding t-Test (ST) was used to determine the abrupt change time of runoff in flood season within typical cross-sections of upper, middle, and lower reaches of Ganjiang River Basin, Ji’an, and Waizhou. Indicators of hydrological change (IHA), range of variability approach (RVA), and other methods were used to analyze the changes of 32 hydrological indicators in Ganjiang River Basin. The results showed that (1) The annual and flood season precipitation in Ganjiang River Basin increased from 1992 to 2016, but it did not reach a significant level. The change of annual runoff at Dongbei and Waizhou Stations was the same as that of the annual precipitation in Ganjiang River Basin. The runoff of Dongbei Station in flood season decreased from 1986 to 2016, and the runoff of Waizhou Railway Station in flood season decreased from 2008 to 2016. It showed that precipitation had a great influence on annual runoff, and human activities made the annual runoff distribution process more uniform; (2) The abrupt changes of runoff in flood season at three hydrological stations in Ganjiang River Basin occurred in 1991, and reached a significant level of 0.01; (3) There were five hydrological indicators of Dongbei Station which had reached height change. The change degree of low (l) pulse duration was −92.24%, the change degree of high (h) pulse count was −86.8%, the change degree of flow rise rate was 87.06%, the change degree of fall rate was −92.24%, and the change degree of number of reversals was −100%. Four hydrological indicators of Ji’an Station had reached high change degree, the count and duration of high pulse changes were −73.33% and −73.65%, the change degree of fall rate was −79%, and the change degree of number of reversals was −100%. Waizhou Station did not reach the high change indicator. The hydrological regime of the upper and middle reaches of Ganjiang River has changed greatly, while the hydrological regime of the lower reaches has changed little. The hydrological regime in the upper and middle reaches of Ganjiang River Basin has been highly changed by human activities such as dam construction. The change of hydrological conditions in the upper and middle reaches of Ganjiang River Basin may reduce the area of aquatic organisms’ habitat, be harmful to the spawning, migration, and survival of aquatic organisms, reduce the interception of organic matter in floodplains, and increase the drought pressure of plants. The reservoir ecological operation of rivers with numerous reservoirs should be considered, joint reservoir dispatching schemes should be formulated for the study area so as to maximize the comprehensive benefits. This study provides a reference for water resources management and reservoir operation in Ganjiang River Basin. The next step is to use a habitat model to simulate the habitat of Ganjiang River Basin.
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Zhao, Liang, Yu Liu e Yong Luo. "Assessing Hydrological Connectivity Mitigated by Reservoirs, Vegetation Cover, and Climate in Yan River Watershed on the Loess Plateau, China: The Network Approach". Water 12, n. 6 (18 giugno 2020): 1742. http://dx.doi.org/10.3390/w12061742.
Testo completoAbstract (sommario):
Hydrologic connectivity is related to the water-mediated transport of matter, energy, and organisms within or between elements of the hydrologic cycle. It reflects the hydrological consequences caused by topographic, land cover, and climatic factors, and is an important tool to characterize and predict the hydrological responses to climate and landscape change. In the Loess Plateau region, a large number of reservoirs have been constructed to trap sediment and storage water for drinking, irrigation, and industries. The land cover has been significantly reshaped in the past decades. These changes may alter the watershed hydrological connectivity. In this study, we mapped the spatial pattern of hydrological connectivity with consideration of reservoir impedances, mitigation of climate, and land cover in the Yan River watershed on the Loess Plateau by using the network index (NI) approach that is based on topographical wetness index. Three wetness indices were used, i.e., topographical wetness index (TWI), SAGA (System for Automated Geoscientific Analyses) wetness index (WIS), and wetness index adopted aridity index (AI) determined by precipitation and evapotranspiration (WIPE). In addition, the effective catchment area (ECA) was also employed to reveal the connectivity of reservoirs and river networks to water source areas. Results show that ECA of reservoirs and rivers account for 35% and 65%, respectively; the hydrological connectivity to the reservoir was lower than that to the river networks. The normalized hydrological connectivity revealed that the connectivity to river channels maintained the same distribution pattern but with a decreased range after construction of reservoirs. As revealed by comparing the spatial patterns of hydrological connectivity quantified by NI based on WIS and WIPE respectively, vegetation cover patterns had significantly alternated watershed hydrological connectivity. These results imply a decreased volume of flow in river channels after reservoir construction, but with same temporal period of flow dynamic. It is illustrated that the network index (NI) is suitable to quantify the hydrological connectivity and it is dynamic in the context of human intervention and climate change.
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Ryu, Jae-Hee, Ji-Eun Kim, Jin-Young Lee, Hyun-Han Kwon e Tae-Woong Kim. "Estimating Optimal Design Frequency and Future Hydrological Risk in Local River Basins According to RCP Scenarios". Water 14, n. 6 (17 marzo 2022): 945. http://dx.doi.org/10.3390/w14060945.
Testo completoAbstract (sommario):
In South Korea, flood damage mainly occurs around rivers; thus, it is necessary to determine the optimal design frequency for river basins to prevent flood damage. However, there are not enough studies showing the effect of climate change on hydrologic design frequency. Therefore, to estimate the optimal design frequency according to future climate change scenarios, this study examined urban flooding area and extreme rainfall frequency that can change in the future. After estimating the optimal design frequency, hydrological risks of 413 local river basins were evaluated according to Representative Concentration Pathway (RCP) scenarios 4.5 and 8.5 after regenerating daily rainfalls from the HadGEM2-ES model into hourly rainfalls using the Poisson cluster. For the RCP 4.5, hydrological risks increased relative to the established design frequency by 3.13% on average. For the RCP 8.5, hydrological risks increased by 2.80% on average. The hydrological risks increased by 4.58% in the P2(2040–2069) period for the RCP 4.5, and by 4.39% in the P1 (2021–2039) period for the RCP 8.5. These results suggest that the hydrologic design frequency in the future will likely decrease, and the safety of river basins will also decrease.
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Gutiérrez, A. G., J. J. Armesto, M. F. Díaz e A. Huth. "Sensitivity of North Patagonian temperate rainforests to changes in rainfall regimes: a process-based, dynamic forest model". Biogeosciences Discussions 9, n. 6 (4 giugno 2012): 6293–333. http://dx.doi.org/10.5194/bgd-9-6293-2012.
Testo completoAbstract (sommario):
Abstract. Rainfall changes due to climate change and their potential impacts on forests demand the development of predictable tools coupling vegetation dynamics to hydrologic processes. Such tools need to be accurate at local scales (i.e. < 100 ha) to develop efficient forest management strategies for climate change adaptation. In this study, we developed and tested a dynamic forest model to predict hydrological balance of North Patagonian temperate rainforests on Chiloé Island, Chile (42° S). The developed model includes detailed calculations of forest water fluxes and incorporates the dynamical linkage of rainfall regimes to soil moisture, and individual tree growth. We confronted model results with detailed field measurements of water fluxes in a young secondary stand (YS). We used the model to compare forest sensitivity in the YS and an old-growth stand (OG, > 500 yr-old), i.e. changes in forest evapotranspiration, soil moisture and forest structure (biomass and basal area). We evaluated sensitivity using changes in rainfall regimes comparable to future climatic scenarios for this century in the study region. The model depicted well the hydrological balance of temperate rainforests. We found a higher evapotranspiration in OG than YS under current climatic conditions. Dryer climatic conditions predicted for this century in the study area led to changes in the hydrological balance that impacted forest structure, with stronger impacts in OG. Changes in climatic parameters decreased evapotranspiration (up to 15 % in OG compared to current values) and soil moisture to 32 % . These changes in water fluxes induced decreases in above-ground biomass in OG (up to 27 %). Our results support the use of the model for detailed analyses of climate change impacts on hydrological balance of forests. Also, it provides a tool suitable for analyses of the impacts of multiple drivers of global change on forest processes (e.g., climate change, fragmentation, forest management).
22
Hoang, Long Phi, Hannu Lauri, Matti Kummu, Jorma Koponen, Michelle T. H. van Vliet, Iwan Supit, Rik Leemans, Pavel Kabat e Fulco Ludwig. "Mekong River flow and hydrological extremes under climate change". Hydrology and Earth System Sciences 20, n. 7 (29 luglio 2016): 3027–41. http://dx.doi.org/10.5194/hess-20-3027-2016.
Testo completoAbstract (sommario):
Abstract. Climate change poses critical threats to water-related safety and sustainability in the Mekong River basin. Hydrological impact signals from earlier Coupled Model Intercomparison Project phase 3 (CMIP3)-based assessments, however, are highly uncertain and largely ignore hydrological extremes. This paper provides one of the first hydrological impact assessments using the CMIP5 climate projections. Furthermore, we model and analyse changes in river flow regimes and hydrological extremes (i.e. high-flow and low-flow conditions). In general, the Mekong's hydrological cycle intensifies under future climate change. The scenario's ensemble mean shows increases in both seasonal and annual river discharges (annual change between +5 and +16 %, depending on location). Despite the overall increasing trend, the individual scenarios show differences in the magnitude of discharge changes and, to a lesser extent, contrasting directional changes. The scenario's ensemble, however, shows reduced uncertainties in climate projection and hydrological impacts compared to earlier CMIP3-based assessments. We further found that extremely high-flow events increase in both magnitude and frequency. Extremely low flows, on the other hand, are projected to occur less often under climate change. Higher low flows can help reducing dry season water shortage and controlling salinization in the downstream Mekong Delta. However, higher and more frequent peak discharges will exacerbate flood risks in the basin. Climate-change-induced hydrological changes will have important implications for safety, economic development, and ecosystem dynamics and thus require special attention in climate change adaptation and water management.
23
Zhang, Xuan, Yang Xu, Fanghua Hao, Chong Li e Xiao Wang. "Hydrological Components Variability under the Impact of Climate Change in a Semi-Arid River Basin". Water 11, n. 6 (29 maggio 2019): 1122. http://dx.doi.org/10.3390/w11061122.
Testo completoAbstract (sommario):
With increased attention paid to the changes of global climate, the impacts on hydrological processes remain poorly understood in specific basins. In this study, we selected Luanhe River Basin, which is an important source of water supply to Beijing and Hebei, as a case study for the analysis of the combined impact of precipitation and temperature change to hydrological components in a semi-arid river basin. This study investigated the change of the blue water flow (BWF), green water flow (GWF), and green water storage (GWS) by employing the SWAT (Soil and Water Assessment Tool) model and stochastic methods in different time scales during 1960 to 2017. The contribution of climate changes to hydrological change were quantified by 16 hypothetical scenarios by recombining climatic data. The results show that the annual daily maximum and minimum temperature (Tmax, Tmin) increased while their differences (DTR) decreased. However, there was no significant trend in annual precipitation and hydrological components. The trend of precipitation has a positive impact to the change of all three hydrological components. Although precipitation contributes more to changes in hydrological components, more attention also needs to be given to the change of DTR, which has positive impact of GWF that contrasts with that of BWF and GWS. Seasonal scale studies of these changes suggested that more attention should be paid to the climate change in spring and winter when the hydrological components were more sensitive to climate change. Our results summarized hydrological components variability under the impact of climate change and demonstrated the importance of analyses at different time scales, which was expected to provide a reference for water resources management in other semi-arid river basins.
24
Hoang, L. P., H. Lauri, M. Kummu, J. Koponen, M. T. H. van Vliet, I. Supit, R. Leemans, P. Kabat e F. Ludwig. "Mekong River flow and hydrological extremes under climate change". Hydrology and Earth System Sciences Discussions 12, n. 11 (10 novembre 2015): 11651–87. http://dx.doi.org/10.5194/hessd-12-11651-2015.
Testo completoAbstract (sommario):
Abstract. Climate change poses critical threats to water related safety and sustainability in the Mekong River basin. Hydrological impact signals derived from CMIP3 climate change scenarios, however, are highly uncertain and largely ignore hydrological extremes. This paper provides one of the first hydrological impact assessments using the most recent CMIP5 climate change scenarios. Furthermore, we model and analyse changes in river flow regimes and hydrological extremes (i.e. high flow and low flow conditions). Similar to earlier CMIP3-based assessments, the hydrological cycle also intensifies in the CMIP5 climate change scenarios. The scenarios ensemble mean shows increases in both seasonal and annual river discharges (annual change between +5 and +16 %, depending on location). Despite the overall increasing trend, the individual scenarios show differences in the magnitude of discharge changes and, to a lesser extent, contrasting directional changes. We further found that extremely high flow events increase in both magnitude and frequency. Extremely low flows, on the other hand, are projected to occur less often under climate change. Higher low flows can help reducing dry season water shortage and controlling salinization in the downstream Mekong Delta. However, higher and more frequent peak discharges will exacerbate flood risk in the basin. The implications of climate change induced hydrological changes are critical and thus require special attention in climate change adaptation and disaster-risk reduction.
25
Guo, Wenxian, Jianwen Hu e Hongxiang Wang. "Analysis of Runoff Variation Characteristics and Influencing Factors in the Wujiang River Basin in the Past 30 Years". International Journal of Environmental Research and Public Health 19, n. 1 (30 dicembre 2021): 372. http://dx.doi.org/10.3390/ijerph19010372.
Testo completoAbstract (sommario):
Changes in climate and the underlying surface are the main factors affecting runoff. Quantitative assessment of runoff characteristics, and determination of the climate and underlying surface contribution to changes in runoff are critical to water resources management and protection. Based on the runoff data from the Wulong Hydrological Station, combined with the Mann-Kendall test, Indicators of Hydrologic Alteration (IHA), Budyko hypothesis, and changes in climate and the underlying surface, this study comprehensively analyzed the runoff in the Wujiang River Basin (WRB). The results showed that: (1) The annual runoff of Wujiang River showed a downward trend, and an abrupt change occurred in 2005. (2) The overall hydrological change in WRB is 46%, reaching a moderate change. (3) The contribution rates of precipitation (P), potential evaporation (ET0), and underlying surface to runoff changes are 61.5%, 11.4%, and 26.9%, respectively. (4) After 2005, the WRB has become more arid, human activities have become more active, vegetation coverage has increased, and the built-up land has increased significantly.
26
Peel, Murray C., e Günter Blöschl. "Hydrological modelling in a changing world". Progress in Physical Geography: Earth and Environment 35, n. 2 (31 marzo 2011): 249–61. http://dx.doi.org/10.1177/0309133311402550.
Testo completoAbstract (sommario):
Changing hydrological conditions due to climate, land use and infrastructure pose significant ongoing challenges to the hydrological research and water management communities. While, traditionally, hydrological models have assumed stationary conditions, there has been much progress since 2005 on model parameter estimation under unknown or changed conditions and on techniques for modelling in those conditions. There is an analogy between extrapolation in space (termed Prediction in Ungauged Basins, PUB), and extrapolation in time (termed Prediction in Ungauged Climates, PUC) that can be exploited for estimating model parameters. Methods for modelling changing hydrological conditions need to progress beyond the current scenario approach, which is reliant upon precalibrated models. Top-down methods and analysis of spatial gradients of a variable of interest, instead of temporal gradients (a method termed ‘Trading space for time’) show much promise for validating more complex model projections. Understanding hydrological processes and how they respond to change, along with quantification of parameter estimation and modelling process uncertainty will continue to be active areas of research within hydrology. Contributions from these areas will not only help inform future climate change impact studies about what will change and by how much, but also provide insight into why any changes may occur, what changes we are able to predict in a realistic manner, and what changes are beyond the current predictability of hydrological systems.
27
Chen, Qihui, Hua Chen, Jinxing Wang, Ying Zhao, Jie Chen e Chongyu Xu. "Impacts of Climate Change and Land-Use Change on Hydrological Extremes in the Jinsha River Basin". Water 11, n. 7 (7 luglio 2019): 1398. http://dx.doi.org/10.3390/w11071398.
Testo completoAbstract (sommario):
Hydrological extremes are closely related to extreme hydrological events, which have been and continue to be one of the most important natural hazards causing great damage to lives and properties. As two of the main factors affecting the hydrological cycle, land-use change and climate change have attracted the attention of many researchers in recent years. However, there are few studies that comprehensively consider the impacts of land-use change and climate change on hydrological extremes, and few researchers have made a quantitative distinction between them. Regarding this problem, this study aims to quantitatively distinguish the effects of land-use change and climate change on hydrological extremes during the past half century using the method of scenarios simulation with the soil and water assessment tool (SWAT). Furthermore, the variations of hydrological extremes are forecast under future scenarios by incorporating the downscaled climate simulations from several representative general circulation models (GCMs). Results show that: (1) respectively rising and declining risks of floods and droughts are detected during 1960–2017. The land use changed little during 1980–2015, except for the water body and building land. (2) The SWAT model possesses better simulation effects on high flows compared with low flows. Besides, the downscaled GCM data can simulate the mean values of runoff well, and acceptable simulation effects are achieved for the extreme runoff indicators, with the exception of frequency and durations of floods and extreme low flows. (3) During the period 1970–2017, the land-use change exerts little impact on runoff extremes, while climate change is one of the main factors leading to changes in extreme hydrological situation. (4) In the context of global climate change, the indicators of 3-day max and 3-day min runoff will probably increase in the near future (2021–2050) compared with the historical period (1970–2005). This research helps us to better meet the challenge of probably increased flood risks by providing references to the decision making of prevention and mitigation measures, and thus possesses significant social and economic value.
28
Chiew, F. H. S., H. Zheng e J. Vaze. "Implication of calibration period on modelling climate change impact on future runoff". Proceedings of the International Association of Hydrological Sciences 371 (12 giugno 2015): 3–6. http://dx.doi.org/10.5194/piahs-371-3-2015.
Testo completoAbstract (sommario):
Abstract. This paper explores the consideration and implication of calibration period on the modelled climate change impact on future runoff. The results show that modelled runoff and hydrologic responses can be influenced by the choice of historical data period used to calibrate and develop the hydrological model. Modelling approaches that do not take this into account may therefore underestimate the range and uncertainty in future runoff projections. Nevertheless, the uncertainty associated with the choice of hydrological models and consideration of calibration dataset for modelling climate change impact on runoff is likely to be small compared to the uncertainty in the future rainfall projections.
29
Andréasson, Johan, Sten Bergström, Bengt Carlsson, L. Phil Graham e Göran Lindström. "Hydrological Change – Climate Change Impact Simulations for Sweden". AMBIO: A Journal of the Human Environment 33, n. 4 (giugno 2004): 228–34. http://dx.doi.org/10.1579/0044-7447-33.4.228.
Testo completo
30
Cassardo, Claudio. "Changes in hydrological budget components induced by climate change". Quaternary International 279-280 (novembre 2012): 82. http://dx.doi.org/10.1016/j.quaint.2012.07.363.
Testo completo
31
Qi, Peng, Y. Jun Xu e Guodong Wang. "Quantifying the Individual Contributions of Climate Change, Dam Construction, and Land Use/Land Cover Change to Hydrological Drought in a Marshy River". Sustainability 12, n. 9 (6 maggio 2020): 3777. http://dx.doi.org/10.3390/su12093777.
Testo completoAbstract (sommario):
Hydrological drought for marshy rivers is poorly characterized and understood. Our inability to quantify hydrological drought in marshy river environments stems from the lack of understanding how wetland loss in a river basin could potentially change watershed structure, attenuation, storage, and flow characteristics. In this study, hydrological drought in a marshy river in far Northeast China at a higher latitude was assessed with a streamflow drought index (SDI). A deterministic, lumped, and conceptual Rainfall–Runoff model, the NAM (Nedbor Afstromnings Model), was used to quantify the individual contributions of climate change, land use/land cover (LULC) change, and river engineering to hydrological drought. We found that in the last five decades, the frequency of hydrological droughts has been 55% without considering LULC change and reservoir construction in this wetland-abundant area. The frequency of hydrological drought increased by 8% due to land use change and by 19% when considering both the impacts of LULC change and a reservoir construction (the Longtouqiao Reservoir). In addition to the more frequent occurrence of hydrological droughts, human activities have also increased drought intensity. These findings suggest that LULC and precipitation changes play a key role in hydrological drought, and that the effect can be significantly modified by a river dam construction.
32
Ruiz-García, Víctor H., Carlos Asensio-Grima, A. Guillermo Ramírez-García e Alejandro Ismael Monterroso-Rivas. "The Hydrological Balance in Micro-Watersheds Is Affected by Climate Change and Land Use Changes". Applied Sciences 13, n. 4 (15 febbraio 2023): 2503. http://dx.doi.org/10.3390/app13042503.
Testo completoAbstract (sommario):
Temperate forests are key to the balance and provision of hydrological and environmental services. Currently, these forests are subject to human alterations as well as to the effects of global change, including warming, variability, deforestation, and forest fires. As a consequence, the hydrological balance has been modified. The present study simulates the effects of climate change and land use change on the hydrological balance of micro-watersheds in Mexico using the hydrological model Water Evaluation and Planning (WEAP). The land use change between 1995 and 2021 was estimated to establish a baseline. Climate scenario SSP585 was projected using three global models, MPI-ESM1-2-LR, HadGEM3-GC31-LL, and CNRM-CM6-1 by the 2081–2100 horizon, along with two scenarios of land use change: one with forest permanence and another with loss of forest cover and increased forest fires. Results indicate that future climatic conditions will modify the hydrological balance at the microbasin level. Even with positive conditions of forest permanence, increases in surface runoff of 124% (CNRM), 35% (HadGEM3), and 13% (MPI) are expected. The projections of coverage loss and fires showed surface runoff increases of 338% (CNRM), 188% (HadGEM3), and 143% (MPI). In the high areas of the microbasins where temperate forest predominates, climatic variations could be contained. If the forest is conserved, surface runoff decreases by −70% (CNRM), −87% (HadGEM3), and −89% (MPI). Likewise, the moisture in the soil increases. In areas with temperate forests, there will be modifications of the hydrological balance mainly due to the increase in evapotranspiration (due to the increase in temperature and precipitation). This will cause a significant decrease in flow and interflow. The alteration of these flows will decrease water availability in soil for infiltration. It is expected that the availability of hydrological and environmental services will be compromised in the entire study area due to climate change.
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Tsarouchi, Gina, e Wouter Buytaert. "Land-use change may exacerbate climate change impacts on water resources in the Ganges basin". Hydrology and Earth System Sciences 22, n. 2 (27 febbraio 2018): 1411–35. http://dx.doi.org/10.5194/hess-22-1411-2018.
Testo completoAbstract (sommario):
Abstract. Quantifying how land-use change and climate change affect water resources is a challenge in hydrological science. This work aims to quantify how future projections of land-use and climate change might affect the hydrological response of the Upper Ganges river basin in northern India, which experiences monsoon flooding almost every year. Three different sets of modelling experiments were run using the Joint UK Land Environment Simulator (JULES) land surface model (LSM) and covering the period 2000–2035: in the first set, only climate change is taken into account, and JULES was driven by the CMIP5 (Coupled Model Intercomparison Project Phase 5) outputs of 21 models, under two representative concentration pathways (RCP4.5 and RCP8.5), whilst land use was held fixed at the year 2010. In the second set, only land-use change is taken into account, and JULES was driven by a time series of 15 future land-use pathways, based on Landsat satellite imagery and the Markov chain simulation, whilst the meteorological boundary conditions were held fixed at years 2000–2005. In the third set, both climate change and land-use change were taken into consideration, as the CMIP5 model outputs were used in conjunction with the 15 future land-use pathways to force JULES. Variations in hydrological variables (stream flow, evapotranspiration and soil moisture) are calculated during the simulation period. Significant changes in the near-future (years 2030–2035) hydrologic fluxes arise under future land-cover and climate change scenarios pointing towards a severe increase in high extremes of flow: the multi-model mean of the 95th percentile of streamflow (Q5) is projected to increase by 63 % under the combined land-use and climate change high emissions scenario (RCP8.5). The changes in all examined hydrological components are greater in the combined land-use and climate change experiment. Results are further presented in a water resources context, aiming to address potential implications of climate change and land-use change from a water demand perspective. We conclude that future water demands in the Upper Ganges region for winter months may not be met.
34
Lu, Er, Eugene S. Takle e Jha Manoj. "The Relationships between Climatic and Hydrological Changes in the Upper Mississippi River Basin: A SWAT and Multi-GCM Study". Journal of Hydrometeorology 11, n. 2 (1 aprile 2010): 437–51. http://dx.doi.org/10.1175/2009jhm1150.1.
Testo completoAbstract (sommario):
Abstract Changes in major climatic and hydrological quantities in the upper Mississippi River basin and their interrelationships are studied with the Soil and Water Assessment Tool being driven by the contemporary climate and future scenario simulations of 10 global models in the Intergovernmental Panel on Climate Change (IPCC) Data Archive. Although the seasonal cycles of climate and hydrological quantities simulated by the 10 models have differences, the ensemble is very close to the observation. Ensemble predictions show that with warming in all months, precipitation decreases in summer but increases in all other seasons. Correspondingly, streamflow decreases in all seasons except winter, evapotranspiration decreases in July–September and increases in all other months, and snowmelt increases in winter but decreases in spring and fall. To understand the linkages between the cross-century changes of climate and hydrological quantities and the relative importance of the changes of temperature and precipitation to the changes of hydrological quantities, relationships between interannual variations of these quantities are investigated. It is shown that the change rates of the hydrological quantities with respect to temperature and precipitation obtained from regressions of interannual variations can vary greatly from month to month; however, on a monthly basis, they do not change much from the current to the future periods. Evaluations with these change rates indicate that for interannual variations of hydrological quantities, both variations of temperature and precipitation are important, and their relative importance depends on the month of the year. However, the changes of hydrological quantities from the means of the current years to the means of the future are dominated by warming in all months, and the influence from change of precipitation is much smaller. The changes of the hydrological quantities can be well predicted with the change rates from the warming alone.
35
Yu, Cui Song, e Xiao Na Guo. "Hydrological Frequency Calculation Method Study of Urban Rivers Runoff under Changing Environment". Applied Mechanics and Materials 170-173 (maggio 2012): 2023–26. http://dx.doi.org/10.4028/www.scientific.net/amm.170-173.2023.
Testo completoAbstract (sommario):
The consistency of hydrological series has been destroyed by the impact of human activities and climate change. Hydrological series is consist of certain component and random element. The random and certain components of hydrological series are identified and separated through statistic analysis. The certain element is determined by using hydrologic model while the consistancy of random element is confirmed directly by hydrological frequency curve. And then add them together. The runoff series of the Huangtai Hydrometric Station in the Xiaoqing River is for example. It proves effective and feasible and the result accord with the reality of the basin.
36
Wenng, Hannah, Danny Croghan, Marianne Bechmann e Hannu Marttila. "Hydrology under change: long-term annual and seasonal changes in small agricultural catchments in Norway". Hydrology Research 52, n. 6 (5 ottobre 2021): 1542–58. http://dx.doi.org/10.2166/nh.2021.066.
Testo completoAbstract (sommario):
Abstract In agricultural catchments, hydrological processes are highly linked to particle and nutrient loss and can lead to a degradation of the ecological status of the water. Global warming and land use changes influence the hydrological regime. This effect is especially strong in cold regions. In this study, we used long-term hydrological monitoring data (22–26 years) from small agricultural catchments in Norway. We applied a Mann–Kendall trend and wavelet coherence analysis to detect annual and seasonal changes and to evaluate the coupling between runoff, climate, and water sources. The trend analysis showed a significant increase in the annual and seasonal mean air temperature. In all sites, hydrological changes were more difficult to detect. Discharge increased in autumn and winter, but this trend did not hold for all catchments. We found a strong coherence between discharge and precipitation, between discharge and snow water equivalent and discharge and soil water storage capacity. We detected different hydrological regimes of rain and snow-dominated catchments. The catchments responded differently to changes due to their location and inherent characteristics. Our results highlight the importance of studying local annual and seasonal changes in hydrological regimes to understand the effect of climate and the importance for site-specific management plans.
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Wenng, Hannah, Danny Croghan, Marianne Bechmann e Hannu Marttila. "Hydrology under change: long-term annual and seasonal changes in small agricultural catchments in Norway". Hydrology Research 52, n. 6 (5 ottobre 2021): 1542–58. http://dx.doi.org/10.2166/nh.2021.066.
Testo completoAbstract (sommario):
Abstract In agricultural catchments, hydrological processes are highly linked to particle and nutrient loss and can lead to a degradation of the ecological status of the water. Global warming and land use changes influence the hydrological regime. This effect is especially strong in cold regions. In this study, we used long-term hydrological monitoring data (22–26 years) from small agricultural catchments in Norway. We applied a Mann–Kendall trend and wavelet coherence analysis to detect annual and seasonal changes and to evaluate the coupling between runoff, climate, and water sources. The trend analysis showed a significant increase in the annual and seasonal mean air temperature. In all sites, hydrological changes were more difficult to detect. Discharge increased in autumn and winter, but this trend did not hold for all catchments. We found a strong coherence between discharge and precipitation, between discharge and snow water equivalent and discharge and soil water storage capacity. We detected different hydrological regimes of rain and snow-dominated catchments. The catchments responded differently to changes due to their location and inherent characteristics. Our results highlight the importance of studying local annual and seasonal changes in hydrological regimes to understand the effect of climate and the importance for site-specific management plans.
38
Mutiga, J. K., S. Zhongbo e T. Woldai. "Impacts of agricultural intensification through upscaling of suitable rainwater harvesting technologies in the upper Ewaso Ng'iro North basin, Kenya". Hydrology and Earth System Sciences Discussions 8, n. 2 (7 marzo 2011): 2477–501. http://dx.doi.org/10.5194/hessd-8-2477-2011.
Testo completoAbstract (sommario):
Abstract. Changes in land cover and land use can lead to significant impacts to hydrology by affecting the amount of runoff, soil moisture and groundwater recharge over a range of temporal and spatial scales. However, hydrologic effects of these changes are still an unknown at watershed scale. Moreover, predicting the effects of land cover/use and climate change on hydrological cycle has remained a major challenge. This is because of the complexity and uncertainty of future climate changes making it difficult to predict the consequences. It is against this backdrop that, for sustainable water resources management, assessment of the impacts of land cover/use change on hydrological regime at all scales becomes critical. During this study, we applied the SWAT model to assess the impacts of area hydrology between baseline and alternative scenario (upscaling of rainwater harvesting technologies). Specifically, our overall objective was to quantitatively evaluate the effects of land use changes on watershed hydrology in the upper Ewaso Ng'iro North basin in Kenya. This was achieved by estimating hydrological responses under historical land use scenarios obtained from the multi-temporal satellite imageries of 1987, 1995 and 2003. The model performance was found to be relatively good (Nash and Sutcliffe efficient of 70%). Stream flow analysis was carried out for different parts of the basin to understand its hydrological responses, especially, the behavior of base flow. The results show a decrease in base flow during 1987–2003 period with decreasing forest, bush and grass covers, which can be attributed to poor natural vegetation emanating mainly from overgrazing and deforestation for agricultural activities. In conclusion, the study clearly shows that, assessment of hydrologic effects of land use changes is critical for a sustainable water resources planning and management of the basin.
39
Zhu, Bowen, Xianhong Xie, Yibing Wang e Xuehua Zhao. "The Benefits of Continental-Scale High-Resolution Hydrological Modeling in the Detection of Extreme Hydrological Events in China". Remote Sensing 15, n. 9 (4 maggio 2023): 2402. http://dx.doi.org/10.3390/rs15092402.
Testo completoAbstract (sommario):
High-resolution hydrological modeling is crucial for detecting extreme hydrological events and understanding fundamental terrestrial processes. However, spatial resolutions in current hydrological modeling studies have been mostly constrained to relatively coarse resolution (~10–100 km), and they therefore have a difficult time addressing flooding or drought issues with fine resolutions. In this study, a continental-scale high-resolution hydrological modeling framework (0.0625°, ~6 km) driven by remote sensing products was used to detect extreme hydrological event occurrences in China and evaluated based on the Variable Infiltration Capacity (VIC) model. The results showed that the developed model provided more detailed information than the coarser resolution models (a 0.25° and 1°), thereby capturing the timing, duration, and spatial extent of extreme hydrologic events regarding the 2012 Beijing flood and 2009/10 drought in Hai River Basin. Here, the total water storage changes were calculated based on the VIC model (−0.017 mm/year) and Gravity Recovery and Climate Experiment (GRACE) satellite (−0.203 mm/year) to reflect the water availability caused by climate change and anthropogenic factors. This study found that the 0.0625° dataset could capture detailed changes, thereby providing reliable information during occurrences of extreme hydrological events. The high-resolution model integrated with remote sensing products could be used for accurate evaluations of continental-scale extreme hydrological events and can be valuable in understanding its long-term occurrence and water resource security.
40
Meresa, Hadush, Bernhard Tischbein e Tewodros Mekonnen. "Climate change impact on extreme precipitation and peak flood magnitude and frequency: observations from CMIP6 and hydrological models". Natural Hazards 111, n. 3 (24 gennaio 2022): 2649–79. http://dx.doi.org/10.1007/s11069-021-05152-3.
Testo completoAbstract (sommario):
AbstractChanges in climate intensity and frequency, including extreme events, heavy and intense rainfall, have the greatest impact on water resource management and flood risk management. Significant changes in air temperature, precipitation, and humidity are expected in future due to climate change. The influence of climate change on flood hazards is subject to considerable uncertainty that comes from the climate model discrepancies, climate bias correction methods, flood frequency distribution, and hydrological model parameters. These factors play a crucial role in flood risk planning and extreme event management. With the advent of the Coupled Model Inter-comparison Project Phase 6, flood managers and water resource planners are interested to know how changes in catchment flood risk are expected to alter relative to previous assessments. We examine catchment-based projected changes in flood quantiles and extreme high flow events for Awash catchments. Conceptual hydrological models (HBV, SMART, NAM and HYMOD), three downscaling techniques (EQM, DQM, and SQF), and an ensemble of hydrological parameter sets were used to examine changes in peak flood magnitude and frequency under climate change in the mid and end of the century. The result shows that projected annual extreme precipitation and flood quantiles could increase substantially in the next several decades in the selected catchments. The associated uncertainty in future flood hazards was quantified using aggregated variance decomposition and confirms that climate change is the dominant factor in Akaki (C2) and Awash Hombole (C5) catchments, whereas in Awash Bello (C4) and Kela (C3) catchments bias correction types is dominate, and Awash Kuntura (C1) both climate models and bias correction methods are essential factors. For the peak flow quantiles, climate models and hydrologic models are two main sources of uncertainty (31% and 18%, respectively). In contrast, the role of hydrological parameters to the aggregated uncertainty of changes in peak flow hazard variable is relatively small (5%), whereas the flood frequency contribution is much higher than the hydrologic model parameters. These results provide useful knowledge for policy-relevant flood indices, water resources and flood risk control and for studies related to uncertainty associated with peak flood magnitude and frequency.
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Rajput, Preeti, Manish Kumar Sinha e Ramchandra Taram. "Assessing Future hydrological response of an urban watershed using machine learning based LULC forecasting models". Disaster Advances 17, n. 11 (30 settembre 2024): 35–48. http://dx.doi.org/10.25303/1711da035048.
Testo completoAbstract (sommario):
Urbanization in terms of land-use/cover (LULC) change has a long-term significant impact on the hydrological cycle as the LULC is one of the most important influencing parameters to produce curve number (CN). The drastic change in LULC changes the CN. This change directly affects surface water including peak flows. This study aims to assess the change in surface runoff due to changes in LULC. Hydrological modeling is done for the consistent long-term behavioral study of surface runoff. The area focused on the study is the Kharun river, a tributary of the Mahanadi River. For the assessment of the impact of LULC change on the catchment discharge, a daily-step conceptual model soil and water assessment tool (SWAT) was applied. Landuse maps were prepared with the Landsat Thematic Mapper satellite images. The future land use was forecasted with the technique of spatial statistical modeling. The machine learning (ML) tool is used for quantifying the influences on the LULC change dynamics and producing the LULC map for 2024 and 2030. Remote sensing (RS) and geographic information system (GIS) analysis were coupled with hydrological SWAT modeling to investigate the connection between the LULC change and hydrologic regime. The SWAT Model’s calibration efficiency is verified by comparing the simulated and observed discharge time series at the Patharidih gauge and discharge station. The monthly and daily calibrations were quite satisfactory, with Nash-Sutcliffe an efficiency coefficient of 0.86 and 0.67. This modeling provides reliable information for sustainable management of available water resources of the catchment.
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Hagemann, S., C. Chen, D. B. Clark, S. Folwell, S. N. Gosling, I. Haddeland, N. Hanasaki et al. "Climate change impact on available water resources obtained using multiple global climate and hydrology models". Earth System Dynamics 4, n. 1 (7 maggio 2013): 129–44. http://dx.doi.org/10.5194/esd-4-129-2013.
Testo completoAbstract (sommario):
Abstract. Climate change is expected to alter the hydrological cycle resulting in large-scale impacts on water availability. However, future climate change impact assessments are highly uncertain. For the first time, multiple global climate (three) and hydrological models (eight) were used to systematically assess the hydrological response to climate change and project the future state of global water resources. This multi-model ensemble allows us to investigate how the hydrology models contribute to the uncertainty in projected hydrological changes compared to the climate models. Due to their systematic biases, GCM outputs cannot be used directly in hydrological impact studies, so a statistical bias correction has been applied. The results show a large spread in projected changes in water resources within the climate–hydrology modelling chain for some regions. They clearly demonstrate that climate models are not the only source of uncertainty for hydrological change, and that the spread resulting from the choice of the hydrology model is larger than the spread originating from the climate models over many areas. But there are also areas showing a robust change signal, such as at high latitudes and in some midlatitude regions, where the models agree on the sign of projected hydrological changes, indicative of higher confidence in this ensemble mean signal. In many catchments an increase of available water resources is expected but there are some severe decreases in Central and Southern Europe, the Middle East, the Mississippi River basin, southern Africa, southern China and south-eastern Australia.
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Hagemann, S., C. Chen, D. B. Clark, S. Folwell, S. N. Gosling, I. Haddeland, N. Hanasaki et al. "Climate change impact on available water resources obtained using multiple global climate and hydrology models". Earth System Dynamics Discussions 3, n. 2 (4 dicembre 2012): 1321–45. http://dx.doi.org/10.5194/esdd-3-1321-2012.
Testo completoAbstract (sommario):
Abstract. Climate change is expected to alter the hydrological cycle resulting in large-scale impacts on water availability. However, future climate change impact assessments are highly uncertain. For the first time, multiple global climate (three) and hydrological models (eight) were used to systematically assess the hydrological response to climate change and project the future state of global water resources. The results show a large spread in projected changes in water resources within the climate–hydrology modelling chain for some regions. They clearly demonstrate that climate models are not the only source of uncertainty for hydrological change. But there are also areas showing a robust change signal, such as at high latitudes and in some mid-latitude regions, where the models agree on the sign of projected hydrological changes, indicative of higher confidence. In many catchments an increase of available water resources is expected but there are some severe decreases in central and Southern Europe, the Middle East, the Mississippi river basin, Southern Africa, Southern China and south eastern Australia.
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Krasovskaia, I., e L. Gottschalk. "Stability of River Flow Regimes". Hydrology Research 23, n. 3 (1 giugno 1992): 137–54. http://dx.doi.org/10.2166/nh.1992.0010.
Testo completoAbstract (sommario):
One of the most important consequences of future climate change may be an alteration of the surface hydrological balance, including changes in flow regimes, i.e. seasonal distribution of flow and especially the time of occurrence of high/low flow, which is of vital importance for environmental and economic policies. Classification of flow regimes still has an important role for the analyses of hydrological response to climate change as well as for validating climate models on present climatic and hydrologic data, however, with some modifications in the methodology. In this paper an approach for flow regime classification is developed in this context. Different ways of flow regime classification are discussed. The stability of flow regimes is studied in relation to changes in mean annual temperature and precipitation. The analyses have shown that even rather small changes in these variables can cause changes in river flow regimes. Different patterns of response have been traced for different regions of the Nordic countries.
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Ludwig, R., I. May, R. Turcotte, L. Vescovi, M. Braun, J. F. Cyr, L. G. Fortin et al. "The role of hydrological model complexity and uncertainty in climate change impact assessment". Advances in Geosciences 21 (11 agosto 2009): 63–71. http://dx.doi.org/10.5194/adgeo-21-63-2009.
Testo completoAbstract (sommario):
Abstract. Little quantitative knowledge is as yet available about the role of hydrological model complexity for climate change impact assessment. This study investigates and compares the varieties of different model response of three hydrological models (PROMET, Hydrotel, HSAMI), each representing a different model complexity in terms of process description, parameter space and spatial and temporal scale. The study is performed in the Ammer watershed, a 709 km2 catchment in the Bavarian alpine forelands, Germany. All models are driven and validated by a 30-year time-series (1971–2000) of observation data. It is expressed by objective functions, that all models, HSAMI and Hydrotel due to calibration, perform almost equally well for runoff simulation over the validation period. Some systematic deviances in the hydrographs and the spatial patterns of hydrologic variables are however quite distinct and thus further discussed. Virtual future climate (2071–2100) is generated by the Canadian Regional Climate Model (vers 3.7.1), driven by the Coupled Global Climate Model (vers. 2) based on an A2 emission scenario (IPCC 2007). The hydrological model performance is evaluated by flow indicators, such as flood frequency, annual 7-day and 30-day low flow and maximum seasonal flows. The modified climatic boundary conditions cause dramatic deviances in hydrologic model response. HSAMI shows tremendous overestimation of evapotranspiration, while Hydrotel and PROMET behave in comparable range. Still, their significant differences, like spatially explicit patterns of summerly water shortage or spring flood intensity, highlight the necessity to extend and quantify the uncertainty discussion in climate change impact analysis towards the remarkable effect of hydrological model complexity. It is obvious that for specific application purposes, water resources managers need to be made aware of this effect and have to take its implications into account for decision making. The paper concludes with an outlook and a proposal for future research necessities.
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Liu, Q., Z. Yang, L. Liang e W. Nan. "Do changes in climate or vegetation regulate evapotranspiration and streamflow trends in water-limited basins?" Hydrology and Earth System Sciences Discussions 11, n. 10 (9 ottobre 2014): 11183–202. http://dx.doi.org/10.5194/hessd-11-11183-2014.
Testo completoAbstract (sommario):
Abstract. Interactions between climate change, vegetation, and soil regulate hydrological processes. In this study, it was assumed that vegetation type and extent remained fixed and unchanged throughout the study period, while the effective rooting depth (Ze) changed under climate change scenarios. Budyko's hydrological model was used to explore the impact of climate change and vegetation on evapotranspiration (E) and streamflow (Q) on the static vegetation rooting depth and the dynamic vegetation rooting depth. Results showed that both precipitation (P) and potential evapotranspiration (Ep) exhibited negative trends, which resulted in decreasing trends for dynamic Ze scenarios. Combined with climatic change, decreasing trends in Ze altered the partitioning of P into E and Q. For dynamic scenarios, total E and Q were predicted to be −1.73 and 28.22%, respectively, greater than static scenarios. Although climate change regulated changes in E and Q, the response of Ze to climate change had a greater overall contribution to changes in hydrological processes. Results from this study suggest that with the exception of vegetation type and extent, Ze scenarios were able to alter water balances, which in itself should help to regulate climate change impacts on water resources.
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Huang, Y., W. F. Yang e L. Chen. "Water resources change in response to climate change in Changjiang River basin". Hydrology and Earth System Sciences Discussions 7, n. 3 (25 maggio 2010): 3159–88. http://dx.doi.org/10.5194/hessd-7-3159-2010.
Testo completoAbstract (sommario):
Abstract. Doubtlessly, global climate change and its impacts have caught increasing attention from all sectors of the society world-widely. Among all those affected aspects, hydrological circle has been found rather sensitive to climate change. Climate change, either as the result or as the driving-force, has intensified the uneven distribution of water resources in the Changjiang (Yangtze) River basin, China. In turn, drought and flooding problems have been aggravated which has brought new challenges to current hydraulic works such as dike or reservoirs which were designed and constructed based on the historical hydrological characteristics, yet has been significantly changed due to climate change impact. Thus, it is necessary to consider the climate change impacts in basin planning and water resources management, currently and in the future. To serve such purpose, research has been carried out on climate change impact on water resources (and hydrological circle) in Changjiang River. The paper presents the main findings of the research, including main findings from analysis of historical hydro-meteorological data in Changjiang River, and runoff change trends in the future using temperature and precipitation predictions calculated based on different emission scenarios of the 24 Global Climate Modes (GCMs) which has been used in the 4th IPCC assessment report. In this research, two types of macro-scope statistical and hydrological models were developed to simulate runoff prediction. Concerning the change trends obtained from the historical data and the projection from GCMs results, the trend of changes in water resources impacted by climate change was analyzed for Changjiang River. Uncertainty of using the models and data were as well analyzed.
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Wang, Jingyi, Caihong Hu, Bingyan Ma e Xiaoling Mu. "Rapid Urbanization Impact on the Hydrological Processes in Zhengzhou, China". Water 12, n. 7 (30 giugno 2020): 1870. http://dx.doi.org/10.3390/w12071870.
Testo completoAbstract (sommario):
Changes in the hydrological process caused by urbanization lead to frequent flooding in cities. For fast-growing urban areas, the impact of urbanization on the hydrological process needs to be systematically analyzed. This study takes Zhengzhou as an example to analyze the impact of urbanization on the hydrological process based on 1971–2012 hourly rainfall-runoff data, combining Geographic Information Systems with traditional hydrological methods. Our study indicates that the rain island effect in different districts of city became stronger with the increase of its built-up. The uneven land use resulted in the difference of runoff process. The flood peak lag was 25–30% earlier with the change of land use. The change of flood peak increased by 10–30% with the change of built-up. The runoff coefficient increases by 20–35% with the increase of built-up, and its change increased with the change of land use. Affected by the rain island effect, precipitation tends to occur in areas where built-up is dominant, which overall magnifies the impact of urbanization on the hydrological process. This provides new ideas for urban flood control. Refine flood control standards according to regional land use changes to cope with the hydrological process after urbanization.
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Choi, Woonsup. "Climate change, urbanisation and hydrological impacts". International Journal of Global Environmental Issues 4, n. 4 (2004): 267. http://dx.doi.org/10.1504/ijgenvi.2004.006054.
Testo completo
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Mimikou, Maria, Y. Kouvopoulos, G. Cavadias e N. Vayianos. "Regional hydrological effects of climate change". Journal of Hydrology 123, n. 1-2 (febbraio 1991): 119–46. http://dx.doi.org/10.1016/0022-1694(91)90073-q.
Testo completo