Hydrologic impact of regional climate change for the snow‐fed and glacier‐fed river basins in the Republic of Tajikistan: statistical downscaling of global climate model projections     

S. Kure  S. Jang  N. Ohara  M. L. Kavvas  Z. Q. Chen 《水文研究》2013,27(26):4071-4090

Climate change due to global warming is a public concern in Central Asia. Because of specific orography and climate conditions, the republic of Tajikistan is considered as the main glacial center of Central Asia. In this study, regional climate change impacts in the two large basins of Tajikistan, Pyanj and Vaksh River basins located in the upstream sector of the Amu Darya River basin are analysed. A statistical regression method with model output statistics corrections using the ground observation data, Willmott archived dataset and GSMaP satellite driven dataset, was developed and applied to the basins to downscale the Global Climate Model Projections at a 0.1‐degree grid and to assess the regional climate change impacts at subbasin scale. It was found that snow and glacier melting are of fundamental importance for the state of the future water resources and flooding at the target basins since the air temperature had a clearly increasing trend toward the future. It was also found that the snowfall will decrease, but the rainfall will increase because of the gradual increase in the air temperature. Such changes may result in an increase in flash floods during the winter and the early spring, and in significant changes in the hydrological regime during a year in the future. Furthermore, the risks of floods in the target basins may be slightly increasing because of the increase in the frequencies and magnitudes of high daily precipitation and the increase in the rapid snowmelt with high air temperatures toward the future. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Implications of decadal to century scale glacio‐hydrological change for water resources of the Hood River basin,OR, USA          下载免费PDF全文

Chris Frans  Erkan Istanbulluoglu  Dennis P. Lettenmaier  Garry Clarke  Theodore J. Bohn  Matt Stumbaugh 《水文研究》2016,30(23):4314-4329

In glacier‐fed rivers, melting of glacier ice sustains streamflow during the driest times of the year, especially during drought years. Anthropogenic and ecologic systems that rely on this glacial buffering of low flows are vulnerable to glacier recession as temperatures rise. We demonstrate the evolution of glacier melt contribution in watershed hydrology over the course of a 184‐year period from 1916 to 2099 through the application of a coupled hydrological and glacier dynamics model to the Hood River basin in Northwest Oregon, USA. We performed continuous simulations of glaciological processes (mass accumulation and ablation, lateral flow of ice and heat conduction through supra‐glacial debris), which are directly linked with seasonal snow dynamics as well as other key hydrologic processes (e.g. evapotranspiration and subsurface flow). Our simulations show that historically, the contribution of glacier melt to basin water supply was up to 79% at upland water management locations. We also show that supraglacial debris cover on the Hood River glaciers modulates the rate of glacier recession and progression of dry season flow at upland stream locations with debris‐covered glaciers. Our model results indicate that dry season (July to September) discharge sourced from glacier melt started to decline early in the 21st century following glacier recession that started early in the 20th century. Changes in climate over the course of the current century will lead to 14–63% (18–78%) reductions in dry season discharge across the basin for IPCC emission pathway RCP4.5 (RCP8.5). The largest losses will be at upland drainage locations of water diversions that were dominated historically by glacier melt and seasonal snowmelt. The contribution of glacier melt varies greatly not only in space but also in time. It displays a strong decadal scale fluctuations that are super‐imposed on the effects of a long‐term climatic warming trend. This decadal variability results in reversals in trends in glacier melt, which underscore the importance of long‐time series of glacio‐hydrologic analyses for evaluating the hydrological response to glacier recession. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Uncertainty in hydrologic modelling for estimating hydrologic response due to climate change (Santiam River,Oregon)   总被引：1，自引：0，他引：1  

Christopher G. Surfleet  Desirée Tullos 《水文研究》2013,27(25):3560-3576

This paper explores the predicted hydrologic responses associated with the compounded error of cascading global circulation model (GCM) uncertainty through hydrologic model uncertainty due to climate change. A coupled groundwater and surface water flow model (GSFLOW) was used within the differential evolution adaptive metropolis (DREAM) uncertainty approach and combined with eight GCMs to investigate uncertainties in hydrologic predictions for three subbasins of varying hydrogeology within the Santiam River basin in Oregon, USA. Predictions of future hydrology in the Santiam River include increases in runoff in the fall and winter months and decreases in runoff for the spring and summer months. One‐year peak flows were predicted to increase whereas 100‐year peak flows were predicted to slightly decrease. The predicted 10‐year 7‐day low flow decreased in two subbasins with little groundwater influences but increased in another subbasin with substantial groundwater influences. Uncertainty in GCMs represented the majority of uncertainty in the analysis, accounting for an average deviation from the median of 66%. The uncertainty associated with use of GSFLOW produced only an 8% increase in the overall uncertainty of predicted responses compared to GCM uncertainty. This analysis demonstrates the value and limitations of cascading uncertainty from GCM use through uncertainty in the hydrologic model, offers insight into the interpretation and use of uncertainty estimates in water resources analysis, and illustrates the need for a fully nonstationary approach with respect to calibrating hydrologic models and transferring parameters across basins and time for climate change analyses. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Modeling the effects of climate change projections on streamflow in the Nooksack River basin,Northwest Washington   总被引：1，自引：0，他引：1       下载免费PDF全文

Susan E. Dickerson‐Lange  Robert Mitchell 《水文研究》2014,28(20):5236-5250

The Nooksack River has its headwaters in the North Cascade Mountains and drains an approximately 2000 km² watershed in northwestern Washington State. The timing and magnitude of streamflow in a snowpack‐dominated drainage basin such as the Nooksack River basin are strongly influenced by temperature and precipitation. Projections of future climate made by general circulation models (GCMs) indicate increases in temperature and variable changes in precipitation for the Nooksack River basin. Understanding the response of the river to climate change is crucial for regional water resources planning because municipalities, tribes, and industry depend on the river for water use and for fish habitat. We combine three different climate scenarios downscaled from GCMs and the Distributed‐Hydrology‐Soil‐Vegetation Model to simulate future changes to timing and magnitude of streamflow in the higher elevations of the Nooksack River. Simulations of future streamflow and snowpack in the basin project a range of magnitudes, which reflects the variable meteorological changes indicated by the three GCM scenarios and the local natural variability employed in the modeling. Simulation results project increased winter flows, decreased summer flows, decreased snowpack, and a shift in timing of the spring melt peak and maximum snow water equivalent. These results are consistent with previous regional studies, but the magnitude of increased winter flows and total annual runoff is higher. Increases in temperature dominate snowpack declines and changes to spring and summer streamflow, whereas a combination of increases in temperature and precipitation control increased winter streamflow. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Macroscale hydrological modelling approach for study of large scale hydrologic impacts under climate change in Indian river basins          下载免费PDF全文

D. Raje  P. Priya  R. Krishnan 《水文研究》2014,28(4):1874-1889

In climate‐change studies, a macroscale hydrologic model (MHM) operating over large scales can be an important tool in developing consistent hydrological variability estimates over large basins. MHMs, which can operate at coarse grid resolutions of about 1° latitude by longitude, have been used previously to study climate change impacts on the hydrology of continental scale or global river basins. They can provide a connection between global atmospheric models and water resource systems on large spatial scales and long timescales. In this study, the variable infiltration capacity (VIC) MHM is used to study large scale hydrologic impacts of climate change for Indian river basins. Large‐scale changes in runoff, evapotranspiration and soil moisture for India, as well as station‐scale changes in discharges for three major river basins with distinct climatic and geographic characteristics are examined in this study. Climate model projections for meteorological variables (precipitation, temperature and wind speed) from three general circulation models (GCMs) and three emissions scenarios are used to drive the VIC MHM. GCM projections are first interpolated to a 1° by 1° hydrologic model grid and then bias‐corrected using a quantile–quantile mapping. The VIC model is able to reproduce observed statistics for discharges in the Ganga, Narmada and Krishna basins reasonably well, even at the coarse grid resolution employed using a calibration period for years 1965–1970 and testing period from 1971–1973/1974. An increasing trend is projected for summer monsoon surface runoff, evapotranspiration and soil moisture in most central Indian river basins, whereas a decrease in runoff and soil moisture is projected for some regions in southern India, with important differences arising from GCM and scenario variability. Discharge statistics show increases in mid‐flow and low flow at Farakka station on Ganga River, increased high flows at Jamtara station upstream of Narmada, and increased high, mid‐flow and low flow for Vijayawada station on Krishna River in the future. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Effects of a century of land cover and climate change on the hydrology of the Puget Sound basin     

Lan Cuo  Dennis P. Lettenmaier  Marina Alberti  Jeffrey E. Richey 《水文研究》2009,23(6):907-933

The Puget Sound basin in northwestern Washington, USA has experienced substantial land cover and climate change over the last century. Using a spatially distributed hydrology model (the Distributed Hydrology‐Soil‐Vegetation Model, DHSVM) the concurrent effects of changing climate (primarily temperature) and land cover in the basin are deconvolved, based on land cover maps for 1883 and 2002, and gridded climate data for 1915–2006. It is found that land cover and temperature change effects on streamflow have occurred differently at high and low elevations. In the lowlands, land cover has occurred primarily as conversion of forest to urban or partially urban land use, and here the land cover signal dominates temperature change. In the uplands, both land cover and temperature change have played important roles. Temperature change is especially important at intermediate elevations (so‐called transient snow zone), where the winter snow line is most sensitive to temperature change—notwithstanding the effects of forest harvest over the same part of the basin. Model simulations show that current land cover results in higher fall, winter and early spring streamflow but lower summer flow; higher annual maximum flow and higher annual mean streamflow compared with pre‐development conditions, which is largely consistent with a trend analysis of model residuals. Land cover change effects in urban and partially urban basins have resulted in changes in annual flow, annual maximum flows, fall and summer flows. For the upland portion of the basin, shifts in the seasonal distribution of streamflows (higher spring flow and lower summer flow) are clearly related to rising temperatures, but annual streamflow has not changed much. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

Water source dynamics of high Arctic river basins          下载免费PDF全文

Phillip J. Blaen  David M. Hannah  Lee E. Brown  Alexander M. Milner 《水文研究》2014,28(10):3521-3538

Arctic river basins are amongst the most vulnerable to climate change. However, there is currently limited knowledge of the hydrological processes that govern flow dynamics in Arctic river basins. We address this research gap using natural hydrochemical and isotopic tracers to identify water sources that contributed to runoff in river basins spanning a gradient of glacierization (0–61%) in Svalbard during summer 2010 and 2011. Spatially distinct hydrological processes operating over diurnal, weekly and seasonal timescales were characterized by river hydrochemistry and isotopic composition. Two conceptual water sources (‘meltwater’ and ‘groundwater’) were identified and used as a basis for end‐member mixing analyses to assess seasonal and year‐to‐year variability in water source dynamics. In glacier‐fed rivers, meltwater dominated flows at all sites (typically >80%) with the highest contributions observed at the beginning of each study period in early July when snow cover was most extensive. Rivers in non‐glacierized basins were sourced initially from snowmelt but became increasingly dependent on groundwater inputs (up to 100% of total flow volume) by late summer. These hydrological changes were attributed to the depletion of snowpacks and enhanced soil water storage capacity as the active layer expanded throughout each melt season. These findings provide insight into the processes that underpin water source dynamics in Arctic river systems and potential future changes in Arctic hydrology that might be expected under a changing climate. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Estimating the effects of climate change on the intensification of monsoonal‐driven stream discharge in a Himalayan watershed          下载免费PDF全文

Ram P. Neupane  Jian Yao  Joseph D. White 《水文研究》2014,28(26):6236-6250

Understanding potential hydrologic influences to continued climate change in Himalayan watersheds is important for management of transnational water resources. This study estimates the climate change impacts on hydrologic processes of the Kali Gandaki watershed from central Himalayan region using the Soil and Water Assessment Tool. Daily predicted stream discharge of the basin for 1981–95 following calibration was accurate with Nash Sutcliffe Efficiency value >0.75. Sensitivity analysis of the hydrologic parameters showed the precipitation and temperature lapse rates as the most sensitive parameters to the stream discharge. To assess the influence of continued climate change on hydrologic processes, we modified the weather inputs for the model using average, minimum and maximum temperature, and precipitation changes for the Special Report on Emission Scenarios B1, A1B and A2 derived from 16 General Circulation Models for 2080s. Mean annual stream discharge was approximately 39% higher than current values for the maximum temperature and precipitation changes of the A2 scenario and 22% less for minimum changes of the same scenario. Stream discharge was projected to be changed by +9% during monsoon season and by ?6% during pre‐monsoon season. Snowfall and snow melt were projected to be 30% and 29%, respectively, less than the current average for the maximum temperature and precipitation changes of the A2 scenario. Future simulations showed potential increase in monsoonal stream discharge associated with projected higher precipitation which when coupled with enhanced summer glacier melt might influence the downstream water availability of the basin. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Modelling the effects of land use and climate changes on hydrology in the Ursern Valley,Switzerland          下载免费PDF全文

A. Alaoui  E. Willimann  K. Jasper  G. Felder  F. Herger  J. Magnusson  R. Weingartner 《水文研究》2014,28(10):3602-3614

While many studies have been conducted in mountainous catchments to examine the impact of climate change on hydrology, the interactions between climate changes and land use components have largely unknown impacts on hydrology in alpine regions. They need to be given special attention in order to devise possible strategies concerning general development in these regions. Thus, the main aim was to examine the impact of land use (i.e. bushland expansion) and climate changes (i.e. increase of temperature) on hydrology by model simulations. For this purpose, the physically based WaSiM‐ETH model was applied to the catchment of Ursern Valley in the central Alps (191 km²) over the period of 1983?2005. Modelling results showed that the reduction of the mean monthly discharge during the summer period is due primarily to the retreat of snow discharge in time and secondarily to the reduction in the glacier surface area together with its retreat in time, rather than the increase in the evapotranspiration due to the expansion of the “green alder” on the expense of grassland. The significant decrease in summer discharge during July, August and September shows a change in the regime from b‐glacio‐nival to nivo‐glacial. These changes are confirmed by the modeling results that attest to a temporal shift in snowmelt and glacier discharge towards earlier in the year: March, April and May for snowmelt and May and June for glacier discharge. It is expected that the yearly total discharge due to the land use changes will be reduced by 0.6% in the near future, whereas, it will be reduced by about 5% if climate change is also taken into account. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Understanding changes in the water budget driven by climate change in cryospheric‐dominated watershed of the northeast Tibetan Plateau,China     

Min Xu  Shichang Kang  Xiaoming Wang  Nick Pepin  Hao Wu 《水文研究》2019,33(7):1040-1058

Glacial retreat and the thawing of permafrost due to climate warming have altered the hydrological cycle in cryospheric‐dominated watersheds. In this study, we analysed the impacts of climate change on the water budget for the upstream of the Shule River Basin on the northeast Tibetan Plateau. The results showed that temperature and precipitation increased significantly during 1957–2010 in the study area. The hydrological cycle in the study area has intensified and accelerated under recent climate change. The average increasing rate of discharge in the upstream of the Shule River Basin was 7.9 × 10⁶ m³/year during 1957–2010. As the mean annual glacier mass balance lost ?62.4 mm/year, the impact of glacier discharge on river flow has increased, especially after the 2000s. The contribution of glacier melt to discharge was approximately 187.99 × 10⁸ m³ or 33.4% of the total discharge over the study period. The results suggested that the impact of warming overcome the effect of precipitation increase on run‐off increase during the study period. The evapotranspiration (ET) increased during 1957–2010 with a rate of 13.4 mm/10 years. On the basis of water balance and the Gravity Recovery and Climate Experiment and the Global Land Data Assimilation System data, the total water storage change showed a decreasing trend, whereas groundwater increased dramatically after 2006. As permafrost has degraded under climate warming, surface water can infiltrate deep into the ground, thus changing both the watershed storage and the mechanisms of discharge generation. Both the change in terrestrial water storage and changes in groundwater have had a strong control on surface discharge in the upstream of the Shule River Basin. Future trends in run‐off are forecasted based on climate scenarios. It is suggested that the impact of warming will overcome the effect of precipitation increase on run‐off in the study area. Further studies such as this will improve understanding of water balance in cold high‐elevation regions.  相似文献   

Decoupling the effects of deforestation and climate variability in the Tapajós river basin in the Brazilian Amazon          下载免费PDF全文

Mauricio E. Arias  Eunjee Lee  Fabio Farinosi  Fabio F. Pereira  Paul R. Moorcroft 《水文研究》2018,32(11):1648-1663

Tropical river basins are experiencing major hydrological alterations as a result of climate variability and deforestation. These drivers of flow changes are often difficult to isolate in large basins based on either observations or experiments; however, combining these methods with numerical models can help identify the contribution of climate and deforestation to hydrological alterations. This paper presents a study carried out in the Tapaj?s River (Brazil), a 477,000 km² basin in South‐eastern Amazonia, in which we analysed the role of annual land cover change on daily river flows. Analysis of observed spatial and temporal trends in rainfall, forest cover, and river flow metrics for 1976 to 2008 indicates a significant shortening of the wet season and reduction in river flows through most of the basin despite no significant trend in annual precipitation. Coincident with seasonal trends over the past 4 decades, over 35% of the original forest (140,000 out of 400,000 km²) was cleared. In order to determine the effects of land clearing and rainfall variability to trends in river flows, we conducted hindcast simulations with ED2 + R, a terrestrial biosphere model incorporating fine scale ecosystem heterogeneity arising from annual land‐use change and linked to a flow routing scheme. The simulations indicated basin‐wide increases in dry season flows caused by land cover transitions beginning in the early 1990s when forest cover dropped to 80% of its original extent. Simulations of historical potential vegetation in the absence of land cover transitions indicate that reduction in rainfall during the dry season (mean of ?9 mm per month) would have had an opposite and larger magnitude effect than deforestation (maximum of +4 mm/month), leading to the overall net negative trend in river flows. In light of the expected increase in future climate variability and water infrastructure development in the Amazon and other tropical basins, this study presents an approach for analysing how multiple drivers of change are altering regional hydrology and water resources management.  相似文献   

Simulating the hydrologic impacts of land-cover and climate changes in a semi-arid watershed     

Heyin Chen 《水文科学杂志》2013,58(10):1739-1758

Abstract

Changes in climate and land cover are among the principal variables affecting watershed hydrology. This paper uses a cell-based model to examine the hydrologic impacts of climate and land-cover changes in the semi-arid Lower Virgin River (LVR) watershed located upstream of Lake Mead, Nevada, USA. The cell-based model is developed by considering direct runoff based on the Soil Conservation Service - Curve Number (SCS-CN) method and surplus runoff based on the Thornthwaite water balance theory. After calibration and validation, the model is used to predict LVR discharge under future climate and land-cover changes. The hydrologic simulation results reveal climate change as the dominant factor and land-cover change as a secondary factor in regulating future river discharge. The combined effects of climate and land-cover changes will slightly increase river discharge in summer but substantially decrease discharge in winter. This impact on water resources deserves attention in climate change adaptation planning.