The influence of land use patterns on water quality at multiple spatial scales in a river system

The influence of land use patterns on water quality in a river system is scale‐dependent. In this study, a four‐order hierarchical arrangement method was used to select water sampling sites and to delineate sub‐basins in the Daliao River Basin, China. The 20 sub‐basins were classified into four spatial scales that represented four different stream orders. Pearson correlation analysis was used to quantify relationships between land use composition and the river's physical‐chemical variables for all samples collected. This analysis showed that the presence of forest cover was associated with higher water quality at the scale of the whole basin. The scale effects of land use patterns on water quality were then examined using stepwise multiple regression analysis that compared different land use types with water quality variables. The results from this analysis showed that urban areas, as opposed to forest areas, became the most significant contributors of water pollutants when scale effects were considered. The influence of urban land cover on water pollution was significantly higher at larger scales. The lack of a significant regression correlation for the forest land use type at smaller scales revealed that forest located upstream of the Daliao River Basin did not provide a buffer for improved water quality. Further analysis showed that this result could be because of disproportionate spatial distributions for forest and urban land use types. The topographic characteristics of sub‐basins, such as average slope (S) and size (A), were determined to be secondary explanatory variables that affected land use impacts on stream water quality. Areas with steep slopes were associated with increased water oxygenation, whereas areas with flatter slopes were associated with higher concentrations of pollutants. These results are significant because they can provide a better understanding of the appropriate spatial scale required for effective river basin management in the future. Copyright © 2013 John Wiley & Sons, Ltd.     

Irrigation Effects on Hydro-Climatic Change: Basin-Wise Water Balance-Constrained Quantification and Cross-Regional Comparison

Hydro-climatic changes driven by human land and water use, including water use for irrigation, may be difficult to distinguish from the effects of global, natural and anthropogenic climate change. This paper quantifies and compares the hydro-climatic change effects of irrigation using a data-driven, basin-wise quantification approach in two different irrigated world regions: the Aral Sea drainage basin in Central Asia and the Indian Mahanadi River Basin draining into the Bay of Bengal. Results show that irrigation-driven changes in evapotranspiration and latent heat fluxes and associated temperature changes at the land surface may be greater in regions with small relative irrigation impacts on water availability in the landscape (here represented by the Mahanadi River Basin) than in regions with severe such impacts (here represented by the Aral region). Different perspectives on the continental part of Earth’s hydrological cycle may thus imply different importance assessments of various drivers and impacts of hydro-climatic change. Regardless of perspective, however, actual basin-wise water balance constraints should be accounted to realistically understand and accurately quantify continental water change.     

Assessment of future water provisioning and sediment load under climate and LULC change scenarios in a peninsular river basin,India

Assessment of the impact of changes in climate and land use and land cover (LULC) on ecosystem services (ES) is important for planning regional-scale strategies for sustainability and restoration of ES. The Upper Narmada River Basin (UNRB) in peninsular India has undergone rapid LULC change due to recent agricultural expansion. The impact of future climate and LULC change on ES in the UNRB is quantified and mapped using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST 3.3.0) tool. Our results show that water yield is projected to increase under climate change (about 43% for representative concentration pathway 4.5 for 2031–2040), whereas it is projected to decrease under the LULC change scenario. Sediment export is projected to increase (by 54.53%) under LULC change for 2031–2040. Under the combined effect of climate and LULC change, both water yield and sediment export are expected to increase. Climate change has a greater impact on projected water yield than LULC change, whereas LULC has greater impact on sediment export. Spatial analysis suggests a similar trend of variation in relative difference (RD) of ES in adjacent sub-basins. The quantified changes in ES provisioning will benefit future land management, particularly for operation of the Rani Avanti Bai Sagar Reservoir downstream of the UNRB.     

A comparison of integrated river basin management strategies: A global perspective

In order to achieve the integrated river basin management in the arid and rapid developing region, the Heihe River Basin (HRB) in Northwestern China, one of critical river basins were selected as a representative example, while the Murray–Darling Basin (MDB) in Australia and the Colorado River Basin (CRB) in the USA were selected for comparative analysis in this paper. Firstly, the comparable characters and hydrological contexts of these three watersheds were introduced in this paper. Then, based on comparative studies on the river basin challenges in terms of the drought, intensive irrigation, and rapid industrialization, the hydrological background of the MDB, the CRB and the HRB was presented. Subsequently, the river management strategies were compared in three aspects: water allocation, water organizations, and water act and scientific projects. Finally, we proposed recommendations for integrated river basin management for the HRB: (1) Water allocation strategies should be based on laws and markets on the whole basin; (2) Public participation should be stressed by the channels between governance organizations and local communities; (3) Scientific research should be integrated into river management to understand the interactions between the human and nature.     

Effects of land cover change on streamflow in the interior Columbia River Basin (USA and Canada)

An analysis of the hydrological effects of vegetation changes in the Columbia River basin over the last century was performed using two land cover scenarios. The first was a reconstruction of historical land cover vegetation, c. 1900, as estimated by the federal Interior Columbia Basin Ecosystem Management Project (ICBEMP). The second was current land cover as estimated from remote sensing data for 1990. Simulations were performed using the variable infiltration capacity (VIC) hydrological model, applied at one‐quarter degree spatial resolution (approximately 500 km² grid cell area) using hydrometeorological data for a 10 year period starting in 1979, and the 1900 and current vegetation scenarios. The model represents surface hydrological fluxes and state variables, including snow accumulation and ablation, evapotranspiration, soil moisture and runoff production. Simulated daily hydrographs of naturalized streamflow (reservoir effects removed) were aggregated to monthly totals and compared for nine selected sub‐basins. The results show that, hydrologically, the most important vegetation‐related change has been a general tendency towards decreased vegetation maturity in the forested areas of the basin. This general trend represents a balance between the effects of logging and fire suppression. In those areas where forest maturity has been reduced as a result of logging, wintertime maximum snow accumulations, and hence snow available for runoff during the spring melt season, have tended to increase, and evapotranspiration has decreased. The reverse has occurred in areas where fire suppression has tended to increase vegetation maturity, although the logging effect appears to dominate for most of the sub‐basins evaluated. Predicted streamflow changes were largest in the Mica and Corralin sub‐basins in the northern and eastern headwaters region; in the Priest Rapids sub‐basin, which drains the east slopes of the Cascade Mountains; and in the Ice Harbor sub‐basin, which receives flows primarily from the Salmon and Clearwater Rivers of Idaho and western Montana. For these sub‐basins, annual average increases in runoff ranged from 4·2 to 10·7% and decreases in evapotranspiration ranged from 3·1 to 12·1%. In comparison with previous studies of individual, smaller sized watersheds, the modelling approach used in this study provides predictions of hydrological fluxes that are spatially continuous throughout the interior Columbia River basin. It thus provides a broad‐scale framework for assessing the vulnerability of watersheds to altered streamflow regimes attributable to changes in land cover that occur over large geographical areas and long time‐frames. Copyright © 2000 John Wiley & Sons, Ltd.     

Appraisal of the carbon to nitrogen(C/N)ratio in the bed sediment of the Betwa River,Peninsular India

Bed sediment carbon to nitrogen(C/N) ratio is one of the essential variables reflecting sources of organic matter in river basins.In order to explore the spatial variability in sources of sediment C/N ratios,and the influence of land use and land cover(LULC) changes on the Betwa River basin in Peninsular India,51 river bed sediment samples were collected in December 2016.The coefficient of variation(CV) was35%indicating highly variable biogeochemical parameters.The sediment C/N ratio varied from 2.94 to 10.09.3.21-56.40,and 6.50-76.97 in upstream,mid-stream,and downstream regions,respectively,indicating a progressive change in sources of organic matter and depositional environment.The positive correlation between total carbon(TC) and C/N ratio was increasing in the downstream direction [upstream(+0.560) mid-stream(+0.603) downstream(+0.838)],which is an indication of high deposition and slow decomposition of sedimentary terrigenous organic matter distant from the regions of urban pollution.The LULC change analysis done by remote sensing and Geographic Information System(GIS)methods revealed an adverse change for the forests and barren land and a positive change for the agricultural land and built-up areas.The sediment C/N ratio mapping showed the impact of LULC changes on the sediment quality.The spatial distribution of bed sediment C/N ratio in the Betwa River basin has important reference value for managing organic matter transport in the downstream Yamuna River and Ganga River basin.     

Impact of land-use induced changes on agricultural productivity in the Huang-Huai-Hai River Basin

The water resource allocation is greatly influenced by the land use, agricultural productivity and farmers’ income. Therefore analyzing the impacts of land use changes on agricultural productivity and subsequent effects on farmer’s income is an important basis of the further study on the management mechanism and optimal water resource allocation. Taking the Huang-Huai-Hai River Basin as the study area, this study examined the impacts of conversion from cultivated land to built-up land from 2000–2005 and 2005–2008. Then the agricultural productivity was estimated with the Estimation System for Agricultural Productivity model, and the changes in agricultural productivity caused by land conversion were analyzed. Thereafter, Simultaneous Equations Model was used to analyze the impacts of the conversion from cultivated land to built-up land on the agricultural productivity and subsequent effects on farmer’s income. The results showed that: (1) The agricultural productivity was stable during the whole period, reaching about 2.84 ton/ha, 3.09 ton/ha and 2.80 ton/ha on average in 2000, 2005 and 2008, respectively, but the conversion from cultivated land to built-up land had important influence on the spatial pattern of agricultural productivity. (2) The land productivity, total power of agricultural machinery and the conversion from cultivated land to built-up land had an overall positive effect on the agricultural productivity. (3) The agricultural productivity and gross domestic product had positive influence on the farmers’ income, while the cultivated land area per capita and percentage of farming employee had negative influence, indicating that the farmer’s income was mainly contributed by non-agricultural income. These results in this study showed that optimal land use management can play an important role in promoting virtuous ecosystem cycle and sustainable socioeconomic development, which can also lay an important foundation for further research on the optimal allocation of water resources in the Huang-Huai-Hai River Basin.     

Effects of land cover change on flood peak discharges and runoff volumes: model estimates for the Nyando River Basin,Kenya

The impacts of historical land cover changes witnessed between 1973 and 2000 on the hydrologic response of the Nyando River Basin were investigated. The land cover changes were obtained through consistent classifications of selected Landsat satellite images. Their effects on runoff peak discharges and volumes were subsequently assessed using selected hydrologic models for runoff generation and routing available within the HEC‐HMS. Physically based parameters of the models were estimated from the land cover change maps together with a digital elevation model and soil datasets of the basin. Observed storm events for the simulation were selected and their interpolated spatial distributions obtained using the univariate ordinary Kriging procedure. The simulated flows from the 14 sub‐catchments were routed downstream afterwards to obtain the accrued effects in the entire river basin. Model results obtained generally revealed significant and varying increases in the runoff peak discharges and volumes within the basin. In the upstream sub‐catchments with higher rates of deforestation, increases between 30 and 47% were observed in the peak discharge. In the entire basin, however, the flood peak discharges and volumes increased by at least 16 and 10% respectively during the entire study period. The study successfully outlined the hydrological consequences of the eminent land cover changes and hence the need for sustainable land use and catchment management strategies. Copyright © 2010 John Wiley & Sons, Ltd.     

Reviews on land use change induced effects on regional hydrological ecosystem services for integrated water resources management

This paper proposed to provide valuable information for integrated water resources management through evaluating the research on the interaction mechanism among land use changes, regional hydrological ecosystem services and human well-being. Firstly, the driving mechanism of land use and land cover changes was introduced in this paper. Secondly, the overview of the interaction mechanism among land use and land cover changes, regional hydrological ecosystem services and human well-being was given. Based on the meta-analysis, land use changes have a profound influence on regional hydrological ecosystem services, and the variation of hydrological ecosystem could benefit or impair human well-being. Finally, two suggestions were emphasized for managers or policy makers for the future integrated water resources management: (1) Proper land use makes for the water resource management; (2) Blindly pursuing the provisioning services weakens other services of hydrological ecosystem.     

Impacts of land use and land cover changes on hydrological processes and sediment yield determined using the SWAT model

Land use and land cover (LULC) changes strongly affect local hydrology and sediment yields.The current study focused on a basin in the Brazilian Amazon and had the following three objectives:(1) to perform an effective diagnosis of flow and sediment yield,(2) to evaluate the impacts of LULC changes over the last 40 years on the hydro-sedimentological variables,and (3) to investigate the impacts of the possible trends or breaking points in the flow,surface runoff,and sediment yield series.The Soi...     

Simulated impacts of irrigation on evapotranspiration in a strongly exploited region: a case study of the Haihe River basin,China

Irrigation is the major water supply for crop production in water‐limited regions. However, this important water component is usually neglected or simplified in hydrological modelling primarily because information concerning irrigation is notably difficult to collect. To assess real effects of irrigation on the simulation of evapotranspiration (ET) in water‐limited region, the Community Land Model version 4 was established over a typical semi‐humid agricultural basin in the northern China – the Haihe River basin. In the irrigated cropland, incorporating an irrigation scheme can enhance the simulated ET and improve the simulation of spatial variability of soil moisture content. We found that different configurations in the irrigation scheme do not cause significant differences in the simulated annual ET. However, simulated ET with simulated irrigation differs clearly from that with observed irrigation in mean annual magnitude, long‐term trend and spatial distribution. Once the irrigation scheme is well‐calibrated against observations, it reasonably reproduces the interannual variability of annual irrigation, when irrigation water management is relatively stable. More importantly, parameter calibration should be consistent with the configuration of the source of irrigation water. However, an irrigation scheme with a constant parameter value cannot capture the trend in the annual irrigation amount caused by abrupt changes in agricultural water management. Compared with different remotely sensed ET products, the enhancement in the simulated ET by irrigation is smaller than the differences among these products, and the trend in simulated ET with the observed irrigation cannot be captured correctly by the remotely sensed ET. Copyright © 2014 John Wiley & Sons, Ltd.     

Estimation of land surface evapotranspiration over complex terrain based on multi‐spectral remote sensing data

Land surface evapotranspiration (ET) plays an important role in energy and water balances. ET can significantly affect the runoff yield of a basin and the available water resources in mountainous areas. The existing models to estimate ET are typically applicable to plains, and excessive data are required to calculate the surface fluxes accurately. This study established a simple and practical model capable of depicting the surface fluxes, while using relatively less parameters. Considering the complex terrain, solar radiation was corrected by importing a series of topographic factors. The water deficit index, a measure of land surface wetness, was calculated by applying the f_c (vegetation fractional cover)‐T_rad (land surface temperature) framework in the two‐source trapezoid model for evapotranspiration model to mountainous areas after corrections of temperature based on altitude variations. The model was successfully applied to the Kaidu River Basin, a basin with few gauges located in the east Tien Shan Mountains of China. Based on the time scale extensions, ET was analyzed at different time scales from 2000 to 2013. The results demonstrated that the corrected solar radiation and water deficit index were reasonably distributed in space and that this model is applicable to ungauged catchments, such as the Kaidu River Basin.     

A Simple Reclassification Method for Correcting Uncertainty in Land Use/Land Cover Data Sets Used with Land Surface Models

With increasing computational resources, environmental models are run at finer grid spacing to resolve the land surface characteristics. The land use/land cover (LULC) data sets input into land surface models are used to assign various default parameters from a look-up tables. The objective of this study is to assess the potential uncertainty in the LULC data and to present a reclassification method for improving the accuracy of LULC data sets. The study focuses on the Southern Great Plains and specifically the Walnut River Watershed in southeastern Kansas, USA. The uncertainty analysis is conducted using two data sets: The National Land Cover Dataset 1992 (NLCD 92) and the Gap Analysis Program (GAP) data set, and a reclassification logic tree. A comparison of these data sets showed that they do not agree for approximately 27% of the watershed. Moreover, an accuracy assessment of these two data sets indicated that neither had an overall accuracy as high as 80%. Using the relationships between land-surface characteristics and LULC, a reclassification of the watershed was conducted using a logical model. This model iteratively reclassified the uncertain pixels according to their surface characteristics. The model utilized normalized difference vegetation index (NDVI) measurements during April and July 2003, elevation, and slope. The reclassification yielded a revised LULC dataset that was substantially improved. The overall accuracy of the revised data set was nearly 93%. The study results suggest: (i) as models adopt finer grid spacings, the uncertainty in the LULC data will become significant; (ii) assimilating NDVI into the land-surface models can reduce the uncertainty due to LULC assignment; (iii) the standard LULC data sets must be used with caution when the focus is on local scale; and (iv) reclassification is a valuable means of improving the accuracy of LULC data sets prior to applying them to local issues or phenomena.     

The assessment of surface water resources for the semi‐arid Yongding River Basin from 1956 to 2000 and the impact of land use change

The assessment of surface water resources (SWRs) in the semi‐arid Yongding River Basin is vital as the basin has been in a continuous state of serious water shortage over the last 20 years. In this study, the first version of the geomorphology‐based hydrological model (GBHM) has been applied to the basin over a long period of time (1956–2000) as part of an SWR assessment. This was done by simulating the natural hydrological processes in the basin. The model was first evaluated at 18 stream gauges during the period from 1990 to 1992 to evaluate both the daily streamflows and the annual SWRs using the land use data for 1990. The model was further validated in 2000 with the annual SWRs at seven major stream gauges. Second, the verified model was used in a 45‐year simulation to estimate the annual SWRs for the basin from 1956 to 2000 using the 1990 land use data. An empirical correlation between the annual precipitation and the annual SWRs was developed for the basin. Spatial distribution of the long‐term mean runoff coefficients for all 177 sub‐basins was also achieved. Third, an additional 10‐year (1991–2000) simulation was performed with the 2000 land use data to investigate the impact of land use changes from 1990 to 2000 on the long‐term annual SWRs. The results suggest that the 10‐year land use changes have led to a decrease of 8·3 × 10⁷ m³ (7·9% of total) for the 10‐year mean annual SWRs in the simulation. To our knowledge, this work is the first attempt to assess the long‐term SWRs and the impact of land use change in the semi‐arid Yongding River Basin using a semi‐distributed hillslope hydrological model. Copyright © 2010 John Wiley & Sons, Ltd.     

Organic carbon transport in the Songhua River,NE China: Influence of land use

Carbon transported by rivers is an important component of the global carbon cycle. Here, we report on organic carbon transport along the third largest river in China, the Songhua River, and its major tributaries. Water samples were collected seasonally or more frequently to determine dissolved organic carbon (DOC) and particulate organic carbon (POC) concentrations and C/N and stable carbon isotopic ratios. Principal component analysis and multiple regression analysis of these data, in combination with hydrological records for the past 50 years, were used to determine the major factors influencing the riverine carbon fluxes. Results indicate that the organic carbon in the Songhua River basin is derived mainly from terrestrial sources. In the 2008–2009 hydrological year, the mean concentrations of DOC and POC were 5.87 and 2.36 mg/L, and the estimated fluxes of the DOC and POC were 0.30 and 0.14 t·km^?2·year^?1, respectively. The riverine POC and DOC concentrations were higher in subcatchments with more cropland, but the area‐specific fluxes were lower, owing to decreased discharge. We found that hydrological characteristics and land‐use type (whether forest or cropland) were the most important factors influencing carbon transport in this system. Agricultural activity, particularly irrigation, is the principal cause of changes in water discharge and carbon export. Over the last 50 years, the conversion of forest to cropland has reduced riverine carbon exports mainly through an associated decrease in discharge following increased extraction of water for irrigation.     

Assessment of surface water resources and evapotranspiration in the Haihe River basin of China using SWAT model

Quantitative assessment of surface water resources (SWRs) and evapotranspiration (ET) is essential and significant for reasonably planning and managing water resources in the Haihe River basin which is facing severe water shortage. In this study, a distributed hydrological model of the Haihe River basin was constructed using the Soil and Water Assessment Tool, well considering the reservoirs and agricultural management practices for reasonable simulation. The crop parameters were independently calibrated with the observed crop data at six experimental stations. Then, sensitivity ranks of hydrological parameters were analysed, which suggested the important parameters used for calibration. The model was successfully calibrated using the monthly observed data of discharge in around 1970–1991 and actual ET (ET_a) in 2002–2004 for the mountainous area and Haihe plain, respectively. Meanwhile, good agreements between the simulated and statistical crop yields in 1985–2005 further verified the model's appropriateness. Finally, the calibrated model was used to assess SWRs and ET_a in time and space during 1961–2005. Results showed that the average annual natural SWRs and the ET_a were about 17.5 billion cubic metre and 542 mm, respectively, both with a slight downward trend. The spatial distributions of both SWRs and ET_a were significantly impacted by variations of precipitation and land use. Moreover, the reservoir in operation was the main factor for the noticeable decline of actual SWRs. In the Haihe plain, the ET_a with irrigation was increased by 46% compared with that under rainfed conditions. In addition, this study identified the regions with potential to improve the irrigation effects on water use. Copyright © 2012 John Wiley & Sons, Ltd.     

Assessment of the WATCLASS hydrological model result of the Mackenzie River basin using the GRACE satellite total water storage measurement

Earlier efforts have been geared towards modelling the hydrological water balance of the Mackenzie River basin and its sub‐basins using a coupled land surface–hydrological model for the Canadian cold region known as WATCLASS. The goal of this current study is to effectively inter‐compare the resulting total water storage anomalies estimated from the gravity recovery and climate experiment (GRACE) satellite analysis with those estimated from the atmospheric‐based water balance approach as well as the model output from WATCLASS over the 1 · 8 × 10⁶ km² Mackenzie River basin in Canada. Since the success of the parameter estimation stage of the coupled land surface–hydrological model, WATCLASS over this large catchment, was entirely based on a goodness of fit between the simulated and observed flows, it is often desirable to assess the reliability of the generated state variables prior to concluding on the overall efficiency of this model in reproducing the relevant hydrological processes over this region. A major challenge here lies in finding suitable dataset with which this comparison can be made to further assess the ability of the model in accurately reproducing other mass fluxes. The outcome of this inter‐comparison reveals the potential application of the GRACE‐based approach as a veritable tool required for the closure of the hydrological water balance of the Mackenzie River basin as well as serving as a dependable source of data for the calibration of traditional hydrological models. Copyright © 2009 John Wiley & Sons, Ltd.     

Remote sensing and hydrological measurement based irrigation performance assessments in the upper Amu Darya Delta,Central Asia

In the Aral Sea Basin, where the Central Asian countries compete for limited water resources, reliable information on the actual water use for eight million ha of irrigated land are rare. In this study, spatially distributed land use data, seasonal actual evapotranspiration, and reference evapotranspiration derived from multitemporal MODIS data were combined with in situ water flow measurements for irrigation performance assessments in the upper Amu Darya Delta. The functioning of the major irrigation and drainage which supplies an agricultural area of 270,000 ha in the Uzbek province Khorezm was analysed using water balancing and adequacy indicators of irrigation water use.An average relative evapotranspiration of 95% indicated fulfilled water demands and partly over-irrigation, whereas values below 75% disclosed inadequate water supply in distant parts of the irrigation system. On the other hand, immense water withdrawals of approximately 24,000 m³ ha⁻¹ recorded at the system boundaries between April and September 2005 clearly exceeded the field water demands for cotton cultivation. Only 46% of the total irrigation amounts were consumed for crop production at field level. Throughout the vegetation period, approximately 58% of the total available water left the region as drainage water. Monthly observations of the depleted fraction and the drainage ratio highlighted drainage problems and rising groundwater levels at regional scale. In the most distant downstream subsystem, a high risk of groundwater and soil salinity during the main irrigation phase was found.A combination of high conveyance losses, hydraulic problems, direct linkages between irrigation and drainage, and low field application efficiencies were identified as major reasons for underperforming irrigation. The findings underlined the necessity of water saving and of reconsidering water distribution in Khorezm. The remote sensing approach was concluded as a reliable data basis for regular performance assessments for all irrigation systems in Central Asia.     

On the usefulness of remote sensing input data for spatially distributed hydrological modelling: case of the Tarim River basin in China

The ecological situation of the Tarim River basin in China seriously declined since the early 1950s, mainly due to a strong increase in water abstraction for irrigation purposes. To restore the ecological system and support sustainable development of the Tarim River basin region in China, more hydrological studies are demanded to properly understand the processes of the watershed and efficiently manage the water resources. Such studies are, however, complicated due to the limited data availability, especially in the mountainous headwater regions of the Tarim River basin. This study investigated the usefulness of remote sensing (RS) data to overcome that lack of data in the spatially distributed hydrological modelling of the basin. Complementary to the conventional station‐based (SB) data, the RS products that are directly used in this study include precipitation, evapotranspiration and leaf area index. They are derived from raw image data of the Chinese Fengyun meteorological satellite and from the Moderate Resolution Imaging Spectroradiometer (MODIS). The MODIS land surface temperature was used to calculate the atmospheric temperature lapse rate to describe the temperature dependency on topographical variations. Moreover, MODIS‐based snow cover images were used to obtain model initial conditions and as validation reference for the snow model component. Comparison of model results based on RS input versus conventional SB input exhibited similar results in terms of high and low river runoff extremes, cumulative runoff volumes in both runoff and snow melting seasons and spatial and temporal variability of snow cover. During summer time, when the snow cover shrinks in the permanent glacier region, it was found that the model resolution influences the model results dramatically, hence, showing the importance of detailed (RS based) spatially distributed input data. Copyright © 2011 John Wiley & Sons, Ltd.