Snowmelt Runoff Research Articles

Generation of Ensemble Streamflow Forecasts Using an Enhanced Version of the Snowmelt Runoff Model1

Harshburger, Brian J., Von P. Walden, Karen S. Humes, Brandon C. Moore, Troy R. Blandford, and Albert Rango, 2012. Generation of Ensemble Streamflow Forecasts Using an Enhanced Version of the Snowmelt Runoff Model. Journal of the American Water Resources Association (JAWRA) 48(4): 643‐655. DOI: 10.1111/j.1752‐1688.2012.00642.xAbstract: As water demand increases in the western United States, so does the need for accurate streamflow forecasts. We describe a method for generating ensemble streamflow forecasts (1‐15 days) using an enhanced version of the snowmelt runoff model (SRM). Forecasts are produced for three snowmelt‐dominated basins in Idaho. Model inputs are derived from meteorological forecasts, snow cover imagery, and surface observations from Snowpack Telemetry stations. The model performed well at lead times up to 7 days, but has significant predictability out to 15 days. The timing of peak flow and the streamflow volume are captured well by the model, but the peak‐flow value is typically low. The model performance was assessed by computing the coefficient of determination (R2), percentage of volume difference (Dv%), and a skill score that quantifies the usefulness of the forecasts relative to climatology. The average R2 value for the mean ensemble is >0.8 for all three basins for lead times up to seven days. The Dv% is fairly unbiased (within ±10%) out to seven days in two of the basins, but the model underpredicts Dv% in the third. The average skill scores for all basins are >0.6 for lead times up to seven days, indicating that the ensemble model outperforms climatology. These results validate the usefulness of the ensemble forecasting approach for basins of this type, suggesting that the ensemble version of SRM might be applied successfully to other basins in the Intermountain West.

Satellite Snowcover Monitoring and Snowmelt Runoff Simulation of Manas River in Tianshan Region

The updrafted Snowmelt Runoff Model(SRM) was applied to the daily snowmelt runoff simulation of Manas River based on the spring snowcover monitoring of Tianshan Region by using the NOAA/AVHRR satellite data.The results showed that the coefficient of determination of the simulation could reach 0.89,and the deviation of the runoff volumes was within 5.1.If the parameters can be adjusted according to the method described in this paper,the model will be easily used to the similar basins.

Soil water behaviors and their effects on river runoffs: The Saromabetsu River basin, Hokkaido

The soil water behaviors during rainfall or snowmelt events were explored by monitoring the soil moisture on the slope of forest and grassland in the Saromabetsu river basin, Hokkaido, in the summer season of 200 and the snowmelt season of 200 . The river basin is covered mostly by forest ( .2% in area) and farmland (2 . % in area; mainly grassland, wheat field and corn field). The soil layer, common to the slope of forest and grassland, consisted of porous organic layer (A layer) less than 0. m thick and organic/inorganic (B layer) about 0 m or more thick. The B layer is silty clay with low hydraulic conductivity of 0cm/s order. The -channel profilers ( cm, cm, 2 cm and cm in soil depth) for measurements of volumetric water content (cm /cm ) indicated that, common to rainfall and snowmelt events, the -2 cm layer at forest stores infiltrated water for a few days after events, and then returns to the previous moisture level by gradual drainage. At grassland, the drainage after events was slight except for cm depth. At a rainfall of more than 20 mm/h, the saturated zone appeared at cm depth in forest and at depths of more than cm in grassland. Hence, in the events, the percolation and subsurface flow are judged to be active. The percolation at cm depth of forest and grassland was calculated for rainfall and snowmelt events. Meanwhile, runoff analyses by the tank model revealed that surface and intermediate runoffs occupy more 0% of rainfall or snowmelt runoffs in the Saromabetsu River. As a result, there existed the linear relationship between the total percolation and surface and intermediate runoffs for the runoff events. Hence, it is suggested that the surface and intermediate runoffs from runoff analyses occur as the percolation and subsequent subsurface flow below the soil surface layer.

Shifts in Western North American Snowmelt Runoff Regimes for the Recent Warm Decades

AbstractClimate change–driven shifts in streamflow timing have been documented for western North America and are expected to continue with increased warming. These changes will likely have the greatest implications on already short and overcommitted water supplies in the region. This study investigated changes in western North American streamflow timing over the 1948–2008 period, including the very recent warm decade not previously considered, through (i) trends in streamflow timing measures, (ii) two second-order linear models applied simultaneously over the region to test for the acceleration of these changes, and (iii) changes in runoff regimes. Basins were categorized by the percentage of snowmelt-derived runoff to enable the comparison of groups of streams with similar runoff characteristics and to quantify shifts in snowmelt-dominated regimes. Results indicate that streamflow has continued to shift to earlier in the water year, most notably for those basins with the largest snowmelt runoff component. However, an acceleration of these streamflow timing changes for the recent warm decades is not clearly indicated. Most coastal rain-dominated and some interior basins have experienced later timing. The timing changes are connected to area-wide warmer temperatures, especially in March and January, and to precipitation shifts that bear subregional signatures. Notably, a set of the most vulnerable basins has experienced runoff regime changes, such that basins that were snowmelt dominated at the beginning of the observational period shifted to mostly rain dominated in later years. These most vulnerable regions for regime shifts are in the California Sierra Nevada, eastern Washington, Idaho, and northeastern New Mexico. Snowmelt regime changes may indicate that the time available for adaptation of water supply systems to climatic changes in vulnerable regions are shorter than previously recognized.

降雨係数の推定に関する雨水と融雪水の影響:北海道における土壌侵食抑制に関する研究 (III)

降雨係数の推定に関する雨水と融雪水の影響:北海道における土壌侵食抑制に関する研究 (III)

Accuracy of HEC-HMS and LBRM Models in Simulating Snow Runoffs in Upper Euphrates Basin

Forecasting streamflow is extremely significant in hydrological studies to optimize the operation of water resources systems. Upper Euphrates Basin, which is located in eastern Turkey, is a snow-dominated basin and its runoff is largely affected by snowmelt. Snowmelt is an important water resource to many aspects of hydrology, including water supply, flood control, and erosion. Selection of a suitable tool was necessary to assess potential impacts of climate change on the hydrological cycle of this region. Hydrologic models are useful tools for the prediction of runoffs and interactions among hydrological variables within the hydrologic cycle. Because of limited data availability, lumped conceptual hydrological models are often used instead of distributed hydrological models. To assess the accuracy of lumped conceptual hydrological models, this paper presents simulation results of snowmelt runoffs of Upper Euphrates Basin by using two models that use the temperature index approach to calculate snowmelt pr...

Responses of snowmelt runoff to climatic change in an inland river basin, Northwestern China, over the past 50 years

Abstract. The spatial and temporal variations of snowcover distribution, and snowmelt runoff are considered as sensitive indicators for climatic change. The purpose of this paper is to analyze and forecast the responses of snowmelt runoff to climate change in an inland river basin. The upper basin of Heihe River in Northwestern China was chose as the study area, and the observation data from the meteorological and hydrological stations were utilized to analyze the status and regularity of the climatic change over the past 50 years. Snow cover area was obtained by an optimized technology using Moderate Resolution Imaging Spectroradiometer data with Normalized Difference Snow Index adjustment and topographic correction. A concept of potential snowmelt was suggested to illustrate the response of spatial snowmelt to climate change. The results show that the annual SCA proportion and the potential snowmelt keep an increasing trend since 2000. There is a negative relationship between annual air temperature and SCA proportion from 2000 to 2008. Snowmelt Runoff Model was chose to simulate snowmelt runoff and scenario forecast the change trend of snowmelt runoff in this region. The results show that climatic warming was apparent in the upper basin of Heihe River over the past 50 a. Annual average air temperature of three different weather stations located in the basin has increased 2.1 °C, 2.6 °C and 2.9 °C respectively from 1956 to present. The snowmelt runoff has increased obviously from 1970 to present. With different warming climate scenarios, the results by using SRM simulating showed that the first occurred time of snowmelt runoff shift ahead and discharge become larger as responses of snowmelt runoff to air temperature increasing, and the influence of temperature rising on average discharge of the whole snow season is not obvious.

Evaluation of Short‐to‐Medium Range Streamflow Forecasts Obtained Using an Enhanced Version of SRM1

Harshburger, Brian J., Karen S. Humes, Von P. Walden, Brandon C. Moore, Troy R. Blandford, and Albert Rango, 2010. Evaluation of Short‐to‐Medium Range Streamflow Forecasts Obtained Using an Enhanced Version of SRM. Journal of the American Water Resources Association (JAWRA) 46(3):603‐617. DOI: 10.1111/j.1752‐1688.2010.00437.xAbstract: As demand for water continues to escalate in the western United States, so does the need for accurate streamflow forecasts. Here, we describe a methodology for generating short‐to‐medium range (1 to 15 days) streamflow forecasts using an enhanced version of the Snowmelt Runoff Model (SRM), snow‐covered area data derived from MODIS products, data from Snow Telemetry stations, and meteorological forecasts. The methodology was tested on three mid‐elevation, snowmelt‐dominated basins ranging in size from 1,600 to 3,500 km2. To optimize the model performance and aid in its operational implementation, two enhancements have been made to SRM: (1) the use of an antecedent temperature index method to track snowpack cold content, and (2) the use of both maximum and minimum critical temperatures to partition precipitation into rain, snow, or a mixture of rain and snow. The comparison of retrospective model simulations with observed streamflow shows that the enhancements significantly improve the model performance. Streamflow forecasts generated using the enhanced version of the model compare well with the observed streamflow for the earlier leadtimes; forecast performance diminishes with leadtime due to errors in the meteorological forecasts. The three basins modeled in this research are typical of many mid‐elevation basins throughout the American West, thus there is potential for this methodology to be applied successfully to other mountainous basins.

Relationship between the 0 ℃ Layer Height and the Streamflow of the Urumqi River in the Period of Spring Snowmelt

Change of the 0℃layer height may reflect the circumfluence change of cold air mass and warm air mass in the high altitude.So the 0℃layer height is an effective index,which can be used to reflect air temperature change ahead of schedule in the work of weather forecast.Generally,the change of 0℃layer height is always ahead of the change of the near ground air temperature.Therefore,we think the 0℃layer height is more effective than near ground air temperature in the forecast of the springtime flood.On the basis of collected data of the average daily streamflow of the Urumqi River and 0℃layer height in spring season,in this paper the relationship between 0℃layer height changes and the average daily streamflow of Urumqi River in spring snowmelt period was analyzed using statistical methods.Standardization of the original data was conducted before the statistical analysis. It is found that there were better linear relationship between the average daily streamflow of the Urumqi River and the 0℃layer height at 08 am and 20 pm.The change of the average daily streamflow of the Urumqi River was lagging behind the change of the 0℃layer height.The correlation coefficients between the time series of the average daily streamflow of the Urumqi River and the 0℃layer height for the years from 2003 to 2006 were significant with a confidence level of 95%,except for the year of 2002.Finally,the best regression models were gained by using the time series of the 0℃layer height and the average daily streamflow of the Urumqi River which were obviously correlated.The regression models can be used to forecast the snowmelt run off and snowmelt flood of the Urumqi River.

Modeling river discharge rates in California watersheds

River discharge rates across all California's watershed have been modeled using the NASA version of the Carnegie-Ames-Stanford Approach (CASA) ecosystem model coupled with a surface hydrologic routing scheme previously called the Hydrological Routing Algorithm (HYDRA). To assess CASA-HYDRA's capability to estimate actual water flows in extreme and non-extreme precipitation years, we have organized hundreds of California river gauge records for comparison to monthly model predictions. Previously, CASA-HYDRA snowmelt algorithms were modified with equations from the USDA Snowmelt Runoff Model, which has been designed to predict daily stream flow in mountain basins where snowmelt is a major runoff factor. Based on model predictions of monthly flow rates across 336 stream gauges statewide, the multi-year model-to-measurement correlation between monthly river flow rates was R2=0.72. The model output was 15% higher across all these stream gauges than the measured monthly flow records for 1982–1990. It is plausible that the model would predict higher flow rates statewide than was measured at many gauge locations, due mainly to extensive water diversions for power generation and crop irrigation in the valley growing regions of the state. Predictions for gauges located on the state's North Coast and Sierra regions showed errors distributed fairly evenly throughout the seasons, whereas results for Central Coast and Southern regions showed higher errors mainly during the summer and fall. Future model applications for land cover and climate change in California are outlined.

Book Reviews

Book Reviews

Evaluation of the Snowmelt Runoff Model in the Moroccan High Atlas Mountains using two snow-cover estimates

In the centre of Morocco, the High Atlas mountain range represents the most important water storage for the neighbouring arid plains through liquid and solid precipitation. In this context, we evaluated the performance of the Snowmelt Runoff Model (SRM) on the five main tributary watersheds of the High Atlas range. Due to the very low density of climate stations in the High Atlas, snowfall and snowmelt processes are difficult to monitor using meteorological data alone. In order to compensate for the lack of in situ data, snow maps are also derived from remotely-sensed data. We compared the streamflow forecasting performance when the model is driven by one or the other estimate of snow-covered area. Both estimates are generally comparable in all watersheds, and satisfactory streamflow simulations were obtained at seasonal time scales using both snow-cover products. However, significant differences can be observed for selected storms, with more accurate streamflow predictions being obtained when the remotely-sensed data are used.

Assessment of Snowmelt Runoff Using Remote Sensing and Effect of Climate Change on Runoff

Runoff regimes in Himalayan basins are controlled mainly by melting of snow and ice cover. The air temperature is the principal variable to estimate the importance of the melting of the snow cover when using snowmelt runoff model. Changes in temperature will ultimately affect stream flow and snow/ice melt runoff in particular. Global atmospheric general circulation models (GCMs) have been developed to simulate the present climate and used to predict future climatic changes and its effect. These GCMs have certain disadvantages, therefore another simple approach of hypothetical scenarios have been developed and successfully demonstrated in this study to investigate the effect of changes in temperature. Adopted plausible climate scenarios included three temperature scenarios (T + 1, T + 2, T + 3°C). The effect of these changes has been studied on the stream flow which has contribution from snowmelt, rainfall and base flow in the Satluj basin. It was observed that with the increase in temperature there is not much change in total stream flow, but the distribution of stream flow have changed. More snowmelt runoff occurred earlier due to increased snow melting however, reduced in the monsoon months.

Snowmelt runoff analysis using SRM (Snowmelt Runoff Model)

SRM（Snowmelt Runoff Model）は，実測流量を使ってオンライン，あるいはオンライン的にパラメータの逐次同定や数学的な最適化を行なわなくても動かすことができる集中型モデルであり，これまで，山岳積雪流域の日平均流量の推定に用いられてきた．本研究では，日本有数の豪雪地帯である新潟県魚野川上流域にSRMを適用し，融雪－流出量を推定・検証した．SRMの入力に用いたのは，1993年4月26日，5月12日，5月28日のLandsat/TM画像から計算された流域内の積雪面積率，およびAMeDAS湯沢の日平均気温と日降水量であり，計算結果の検証には国土交通省六日町観測点の日平均流量を用いた．SRMを動かすのに必要なパラメータの一部は，1992年の融雪期における六日町の日平均流量を用いて決定し，客観的に決めるのが難しいパラメータは，魚野川上流域の北東約40 kmに位置する奥只見流域でSRMに適用された値を元に決定した．魚野川上流域で分布型流出モデルを用いて融雪－流出量を推定した先行研究との比較のため，1993年4月23日～5月30日についてNash-Sutcliffe指標を計算した．六日町の観測値とSRMの推定値で計算したNash-Sutcliffe指標は0.82となり，上述したような特徴をもつ集中型モデルであるにも関わらずSRMの推定結果は良好であった．また，4月26日と5月12日の積雪面積率のみを用いて5月13日以降の積雪面積率を外挿した場合でも，上述した期間のNash-Sutcliffe指標は0.83となったことから，SRMは短期～中期の流量計算にも使える可能性がある．

Study on the Distributed Snowmelt Runoff Process Based on RS and GIS

Study on the Distributed Snowmelt Runoff Process Based on RS and GIS

Climate change in western ski areas: Potential changes in the timing of wet avalanches and snow quality for the Aspen ski area in the years 2030 and 2100

Abstract We evaluated how climate change resulting from increased greenhouse gas (GHG) emissions may affect the timing of wet avalanches and snow quality at Aspen Mountain in the years 2030 and 2100. Snow quantity was evaluated using the Snowmelt Runoff Model and snow quality was evaluated using SNTHERM. We determined the timing of wet avalanche activity by examining changes to historical average temperatures and snow quality by calculating the bulk density of the top 10 cm of the snowpack. Climate changes were evaluated using MAGICC/SCENGEN and the output from five General Circulation Models (GCMs). The climate change estimates were run using the relatively low, mid-range, and high GHG emissions scenarios: B1, A1B, and A1FI. To get higher resolution estimates of changes in climate, we used output from a regional climate model (RCM, MM5), which is nested in the Parallel Climate Model (PCM). We defined wet avalanches as likely to occur when average daily temperature exceeds 0 °C and investigated three scenarios: first day when daily average temperature exceeds 0 °C, first three consecutive day period when average temperature exceeds 0 °C, and the day after which average temperature remains greater than 0 °C. By 2030 at the top of Aspen Mountain, wet avalanches are likely to occur between 2 and 19 days earlier than historical averages, with little difference across the GCMs. In 2100, the occurrence of wet avalanches at the top of the mountain varies strongly by CO 2 emissions scenario. The low and mid-range emissions scenarios show that wet avalanches at the top of the mountain start 16 to 27 days earlier than historical averages. In contrast, the high emissions scenario shows wet avalanches occurring 41 to 45 days earlier. In spite of earlier melt initiation and the reduction in snowpack, snow density in the top 10 cm increased by less than 20% by 2030.

積雪浸透を考慮した実用的融雪流出モデルの開発

積雪浸透を考慮した実用的融雪流出モデルの開発

Effects of Frozen Soil on Snowmelt Runoff and Soil Water Storage at a Continental Scale

AbstractThe presence of ice in soil dramatically alters soil hydrologic and thermal properties. Despite this important role, many recent studies show that explicitly including the hydrologic effects of soil ice in land surface models degrades the simulation of runoff in cold regions. This paper addresses this dilemma by employing the Community Land Model version 2.0 (CLM2.0) developed at the National Center for Atmospheric Research (NCAR) and a simple TOPMODEL-based runoff scheme (SIMTOP). CLM2.0/SIMTOP explicitly computes soil ice content and its modifications to soil hydrologic and thermal properties. However, the frozen soil scheme has a tendency to produce a completely frozen soil (100% ice content) whenever the soil temperature is below 0°C. The frozen ground prevents infiltration of snowmelt or rainfall, thereby resulting in earlier- and higher-than-observed springtime runoff. This paper presents modifications to the above-mentioned frozen soil scheme that produce more accurate magnitude and seasonality of runoff and soil water storage. These modifications include 1) allowing liquid water to coexist with ice in the soil over a wide range of temperatures below 0°C by using the freezing-point depression equation, 2) computing the vertical water fluxes by introducing the concept of a fractional permeable area, which partitions the model grid into an impermeable part (no vertical water flow) and a permeable part, and 3) using the total soil moisture (liquid water and ice) to calculate the soil matric potential and hydraulic conductivity. The performance of CLM2.0/SIMTOP with these changes has been tested using observed data in cold-region river basins of various spatial scales. Compared to the CLM2.0/SIMTOP frozen soil scheme, the modified scheme produces monthly runoff that compares more favorably with that estimated by the University of New Hampshire–Global Runoff Data Center and a terrestrial water storage change that is in closer agreement with that measured by the Gravity Recovery and Climate Experiment (GRACE) satellites.

Effect of climatic change on snowmelt runoffs in mountainous regions of inland rivers in Northwestern China

Climatic change has significant impacts on snow cover in mid-latitude mountainous re- gions, in the meantime, spatial and temporal changes of snow cover and snowmelt runoffs are con- sidered as sensitive indicators for climatic change. In this study, the upper Heihe Watershed in the Qilian Mountains was selected as a typical area affected by snow cover and snowmelt runoffs in northwestern China. The changes in air temperatures, precipitation, snowfall and spring snowmelt runoffs were analyzed for the period from 1956 to 2001. The results indicate that climatic warming was apparent, particularly in January and February, but precipitation just fluctuated without a clear trend. The possible changes of snowmelt runoffs in the upper Heihe watershed in response to a warming of 4℃ were simulated using Snowmelt Runoff Model (SRM) based on the degree-day factor algorithm. The results of the simulation indicate that a forward shifting of snow melting season, an increase in water flows in earlier melting season, and a decline in flows in later melting season would occur under a 4℃ warming scenario.

Parameterization of the Snowmelt Runoff Model for the Salt-Verde System, Arizona During Drought Conditions

Abstract The snowmelt season for water years 2001 to 2003 were modeled for the Salt, Tonto, and Verde basins in Arizona using the Snowmelt Runoff Model (SRM). The SRM is a degree-day-driven snowmelt model. The purpose was to assess how well the SRM could simulate the snowmelt runoff conditions in Arizona, an arid subtropical environment that was also experiencing severe drought. Arizona's snowmelt season is characterized by multiple accumulation periods and near complete melt off periods that often occur during midwinter. Successful simulation of the streamflow would necessitate defining the proper values and patterns of the SRM parameters and assessing how this parameterization differs from other basins where the SRM has been run. Correlation coefficient values for modeled and measured streamflow on the Salt, Tonto, and Verde basins were 0.89, 0.89, and 0.91, respectively. Index of agreement values were 0.93, 0.94, and 0.95, respectively. Runoff coefficients increased during the snowmelt season until the...