Runoff Decline Research Articles

Impact Assessment of Climate Change and Human Activities on Runoff Variation in Coal Mining Watershed, NW China

The Kuye river watershed is a coal mining watershed in Northwest China. The study analyzed runoff change of year, high flow period and low flow period in the past 60 years based on Mann-Kendall trend test, cumulative anomaly, and continuous wavelet analysis. The contributions of climate change and human activities on runoff variation were assessed by the rainfall-runoff relationship model. The results were obtained: (1) Runoff in year, high and low flow period showed a significant declining trend during 1954–2015, but the trends of decreasing or increasing of precipitation and evaporation were not notable. (2) Runoff in year, highflow period and low flow period exhibited similar abrupt change feature and stage characteristic. (3) The periodic changing characteristics of runoff in high flow period were similar to those in annual runoff, but those in low flow period were different from annual runoff. (4) The effect of climate change on runoff had an significant decreasing trend from 61.73 to 9.19% in year, from 59.76 to 2.68% in high flow period, and from 25.00 to 2.63% in low flow period. Compared with climate change, the impact of human activities increased obviously, the contribution all over 90.00% in 1997–2015. Thus, human activities demonstrated the dominant influence on runoff decline gradually.

Runoff Predicting and Variation Analysis in Upper Ganjiang Basin under Projected Climate Changes

Catchment runoff is significantly affected by climate condition changes. Predicting the runoff and analyzing its variations under future climates play a vital role in water security, water resource management, and the sustainable development of the catchment. In traditional hydrological modeling, fixed model parameters are usually used to transfer the global climate models (GCMs) to runoff, while the hydrologic model parameters may be time-varying. It is more appropriate to use the time-variant parameter for runoff modeling. This is achieved by incorporating the time-variant parameter approach into a two-parameter water balance model (TWBM) through the construction of time-variant parameter functions based on the identified catchment climate indicators. Using the Ganjiang Basin with an outlet of the Dongbei Hydrological Station as the study area, we developed time-variant parameter scenarios of the TWBM model and selected the best-performed parameter functions to predict future runoff and analyze its variations under the climate model projection of the BCC-CSM1.1(m). To synthetically assess the model performance improvements using the time-variant parameter approach, an index Δ was developed by combining the Nash–Sutcliffe efficiency, the volume error, the Box–Cox transformed root-mean-square error, and the Kling–Gupta efficiency with equivalent weight. The results show that the TWBM model with time-variant C (evapotranspiration parameter) and SC (water storage capacity of catchment), where growing and non-growing seasons are considered for C, outperformed the model with constant parameters with a Δ value of approximately 5% and 10% for the calibration and validation periods, respectively. The mean annual values of runoff predictions under the four representative concentration pathways (RCPs) exhibited a decreasing trend over the future three decades (2021–2050) when compared to the runoff simulations in the baseline period (1982–2011), where the values were about −9.9%, −19.5%, −16.6%, and −11.4% for the RCP2.6, RCP4.5, RCP6.0, and RCP8.5, respectively. The decreasing trend of future precipitation exerts impacts on runoff decline. Generally, the mean monthly changes of runoff predictions showed a decreasing trend from January to August for almost all of the RCPs, while an increasing trend existed from September to November, along with fluctuations among different RCPs. This study can provide beneficial references to comprehensively understand the impacts of climate change on runoff prediction and thus improve the regional strategy for future water resource management.

SWAT-Based Runoff Simulation and Runoff Responses to Climate Change in the Headwaters of the Yellow River, China

Runoff in snowy alpine regions is sensitive to climate change in the context of global warming. Exploring the impact of climate change on the runoff in these regions is critical to understand the dynamics of the water cycle and for the improvement of water resources management. In this study, we analyzed the long-term variations in annual runoff in the headwaters region of the Yellow River (HRYR) (a typical snowy mountain region) during the period of 1956–2012. The Soil and Water Assessment Tool (SWAT) with different elevation bands was employed to assess the performance of monthly runoff simulations, and then to evaluate the impacts of climate change on runoff. The results show that the observed runoff for the hydrological stations at lower relative elevations (i.e., Maqu and Tangnaihai stations) had a downward trend, with rates of 1.91 and 1.55 mm/10 years, while a slight upward trend with a rate of 0.26 mm/10 years was observed for the hydrological station at higher elevation (i.e., Huangheyan station). We also found that the inclusion of five elevation bands could lead to more accurate runoff estimates as compared to simulation without elevation bands at monthly time steps. In addition, the dominant cause of the runoff decline across the whole HRYR was precipitation (which explained 64.2% of the decrease), rather than temperature (25.93%).

Effects of climate change and human activities on runoff in the Beichuan River Basin in the northeastern Tibetan Plateau, China

Climate change and human activities are considered to be the main drivers of runoff changes. Assessing their contributions is important for maintaining the integrity of the water cycle process and promoting the healthy management of water resources. But the contributions of these two factors in the Beichuan River Basin remain unclear. In this study, hydrological and meteorological data from six sub-basins (Niuchang, Xiamen, Heilin, Qiaotou, Dongxia, and Chaoyang) during 1961–2013 were studied to elucidate upon the effects of these processes. Mann-Kendall tests showed that runoff in the Beichuan River Basin showed a downward trend over the study period and revealed that abrupt changes occurred in 1972 and 1989. Therefore, the study period was divided into two periods: a base period and a change period (periods I and II). A climate elasticity model and hydrological sensitivity analysis were used to estimate the contributions of climate change and human activities. We found that the dominant factors in changing runoff were human activities. Due with the conversion of cropland to forest and grassland and increases of construction land, during the change period water supply increases evidently. Among the basin regions, the Chaoyang sub-basin showed the greatest runoff decline and an abrupt change in 1989, and human activities had the greatest contribution to runoff change in this sub-basin. In addition, the conversion of cropland to forest and grassland was most evident in the Chaoyang and Qiaotou sub-basins, and the area of construction land in these two regions increased greatly during the change period.

Multi-Model Approach to Quantify Future Sediment and Pollutant Loads and Ecosystem Change in Selenga River System

The Selenga River, which originates in Mongolia, contributes about 50% of the total inflow into Lake Baikal. Hydroclimatic development and abrupt landscape evolution due to mining, industrial, and agricultural activities within the Selenga drainage basin affect the pollutant influx and transport along the course of the river and its tributaries and influence the riverine ecosystem, including fish habitats. This paper presents a process-based distributed modeling approach for the assessment of water, sediment, and contaminants dynamics and its environmental consequences at river basin scale by integrating various tools at multiple spatial scales. Different water quantity and quality processes were considered and modelled, e.g., the hydrology in the river basin, the erosion and sediment transport and budget, and fish migration. A set of regression models and a climate-driven hydrological model (ECOMAG) were applied to create projections of possible changes to the sediment and pollutants transport regime of the Selenga River and its delta that may occur in response to the projected variations of climate of the XXI century. Climate change may reduce the mean flow in the Selenga River at Kabansk by an average of 3–5% in the 2020s–2030s and 4–25% in the 2080s–2090s, depending on climate projections. The future increase in temperatures with permafrost thaw and the expansion of agricultural and mining activities along with urbanizaiton processes may induce up to 6% increase in the particulate modes and 3%, in the dissolved modes of some metals in the river system. Water runoff decline will dramatically decrease suspended sediment retention in the delta. Depending on the climate change scenario, in the 2080–2099, the suspended sediment load will change in the delta by –0.8% (retention) or by +1% (increase), which is much less than the recent observed average of sediment retention rates –33%. The reduction of runoff will induce a decrease in the migration distance of Baikal omul (Coregonus migratorius)) in the XXI century from 185 to 320 km, with a tendency to an increase towards the end of the century.

Quantifying contributions of climate change and local human activities to runoff decline in the upper reaches of the Luanhe River basin

Climate change and local human activities are regarded as the two main factors influencing runoff. Using observed runoff, there is a statistically significant decreasing trend for annual and monthly runoff detected by the Mann-Kendall’s test, in the upper reaches of Luanhe River basin (URLRB), 1954–2000. With the break point analysis, the whole time series are divided into two sub periods: “natural period (1954–1970) and “impact period” (1971–2000). “Natural runoff” from 1954 to 2000, is reconstructed by the variable infiltration capacity (VIC) model, in which the model parameters are calibrated in “natural period” representing the natural watershed characteristics without the impact of local human activities. By comparing the difference between observed runoff and “natural runoff” in “impact period”, the contributions of climate change and local human activities are quantitatively separated. The results indicate that climate change and local human activities account for 49% and 51%, respectively, on the annual runoff decrease in the URLRB. That means the effects of climate change on runoff are roughly the same as the effects of local human activities. Climate change results in decrease in monthly runoff; and local human activities mainly affect flood season runoff. The results could be a reference for water resources projection and management in the URLRB and other catchments in northern China.

Sensitivity analysis of runoff to climate variability and land-use changes in the Haihe Basin mountainous area of north China

Runoff has changed significantly in most regions in China over the past decades. Climate variability and land-use changes are considered to be the two main factors contributing to runoff variation. Investigating the mechanism of runoff variation is of great significance for the sustainable utilization of water resources. In this study, Mann-Kendall test, double cumulative curve method, and runoff sensitivity analysis method are adopted to separate and quantify the relative impacts of climate variability and land-use changes on runoff. Furthermore, the sensitivities of runoff were estimated with regard to these two factors in north China during the study period from 1957 to 2000. The results revealed a significant decreasing trend in annual runoff and indicated that land-use changes had a greater effect on runoff than climate variability since 1979. The runoff decline due to land-use changes was 68.33%, whereas the runoff decline due to climate variability was only 30.85%. Further analysis of the sensitivities of runoff to climate variability and land-use changes suggested that, with a 10% increase in precipitation, the runoff will increase by 35.1%; while a 10% increase in potential evapotranspiration or the aridity index will induce 25.1% or 27.5% decrease in runoff, respectively. The sensitivity coefficients of runoff to precipitation, potential evapotranspiration and aridity index (εP, εEP and εϕ), and runoff ratio (Q/P) and the aridity index exhibited a significant nonlinear negative correlation (Y = ax−b, R2 > 0.85), and a positive linear correlation (Y = ax + b, R2 < 0.50), respectively. All these results implied that runoff is more sensitive to the regions with water scarcity and drying climate. The average sensitivity coefficients of runoff to forest, grassland, and farmland were 1.46, 1.21 and 1.18, respectively. This means that a 10% increase in forest, grassland, and farmland coverage would induce 1.46, 1.21, and 1.18 mm decrease of runoff, respectively. This demonstrates that forests have the most effective impact on runoff reduction, followed by grassland or farmland.

Changing Seasonal Rainfall Distribution With Climate Directs Contrasting Impacts at Evapotranspiration and Water Yield in the Western Mediterranean Region

AbstractOver the past century, climate change has been reflected in altered precipitation regimes worldwide. Because evapotranspiration is sensitive to both water availability and atmospheric demand for water vapor, it is essential to assess the likely consequences of future changes of these climate variables to evapotranspiration and, thus, runoff. We propose a simplified approach for annual evapotranspiration predictions, based on seasonal evapotranspiration estimates, accounting for the strong seasonality of meteorological conditions typical of Mediterranean climate, still holding the steady state assumption of basin water balance at mean annual scale. Sardinian runoff decreased over the 1975–2010 period by more than 40% compared to the preceding 1922–1974 period. Most of annual runoff in Sardinian basins is produced by winter precipitation, a wet season with relatively high evaporation rates. We derived linear seasonal evapotranspiration responses to seasonal precipitation, and, in turn, a relationship between the parameters of the linear functions and the seasonal vapor pressure deficit (D), accounting for residuals with basin properties. We then used these relationships to predict evapotranspiration and runoff using future Intergovernmental Panel on Climate Change climate scenarios, considering changing precipitation and D seasonality. We show that evapotranspiration is insensitive to D scenario changes. Although both evapotranspiration and runoff are sensitive to precipitation seasonality, future changes in runoff are related only to changes of winter precipitation, while evapotranspiration changes are related to those of spring and summer precipitation. Future scenario predicting further runoff decline is particularly alarming for the Sardinian water resources system, requiring new strategies and designs in water resources planning and management.

Impact of urban expansion on potential flooding, storage and water harvesting in the city of Sharjah, United Arab Emirates

The work presented in this article is an extension of an earlier study [1] in which runoff in the city of Sharjah, United Arab Emirates (UAE), was assessed for the period 1967–2010. In this study, the impacts of urban expansion on potential flooding, storage and water harvesting were assessed for the period 1976–2016 using rainfall data recorded during the same period. Sharjah is a generally a flat coastal city that is located in a dry hot region average rainfall of approximately 100 mm/y. Remote sensing and GIS techniques were used to assess the expansion of built areas in the city using multi-temporal Landsat satellite images. The built areas in the city increased during the study period by approximately four folds while the population increased by more than 10 folds. The study results demonstrate the historical increase in runoff potential, flooding potential and runoff coefficient and decline in water storage potential. The results are consistent with the observed incidence of significant local flooding episodes in urban areas during rainfall events. Furthermore, an assessment of potential urban water harvesting based on expansion of built areas in the city is provided and appropriate urban storm water management practices for the city are recommended.

Attribution analysis of runoff decline in a semiarid region of the Loess Plateau, China

Climate variability and human activities are two main contributing attributions for runoff changes in the Yellow River, China. In the loess hilly-gully regions of the middle Yellow River, water shortage has been a serious problem, and this results in large-scale constructions of soil and water conservation (SWC) measures in the past decades in order to retain water for agricultural irrigation and industrial production. This disturbed the natural runoff characteristics. In this paper, we focused on a typical loess hilly-gully region (Wudinghe and Luhe River basins) and investigated the effects of SWC measures and climate variability on runoff during the period of 1961–2013, while the SWC measures were the main representative of human activities in this region. The nonparametric Mann-Kendall test was used to analyze the changes of annual precipitation, air temperature, potential evapotranspiration (PET), and runoff. The analysis revealed the decrease in precipitation, significant rise in temperature, and remarkable runoff reduction with a rate of more than 0.4 mm per year. It was found that runoff capacity in this region also decreased. Using the change point detection methods, the abrupt change point of annual runoff series was found at 1970, and thus, the study period was divided into the baseline period (1961–1970) and changed period (1971–2013). A conceptual framework based on four statistical runoff methods was used for attribution analysis of runoff decline in the Wudinghe and Luhe River basins (−37.3 and −56.4%, respectively). Results showed that runoff reduction can be explained by 85.2–90.3% (83.3–85.7%) with the SWC measures in the Wudinghe (Luhe) River basin while the remaining proportions were caused by climate variability. The findings suggested that the large-scale SWC measures demonstrated a dominant influence on runoff decline, and the change of precipitation extreme was also a promoting factor of the upward trending of SWC measures’ contribution to runoff decline. This study enhances our understanding of runoff changes caused by SWC measures and climate variability in the typical semiarid region of Loess Plateau, China.

Effects of check dams on runoff and sediment load in a semi-arid river basin of the Yellow River

Check dam has become an efficient measure to control sediment transport and soil erosion in the gully areas. It plays an important role in soil erosion control and agricultural production in the Loess Plateau. Due to construction of numerous check dams, it is necessary to assess the impact of check dams on runoff and sediment load at basin scale. This study applied the SWAT model to simulate monthly runoff and sediment load in the Huangfuchuan basin in the middle reaches of the Yellow River. Twenty key check dams are coupled to the SWAT model simulation in the calibration (1978–1984) and validation period (1985–1989). The determination coefficient (R 2) and the Nash–Sutcliffe coefficient (NS) were 0.94 and 0.83 for runoff, and 0.82 and 0.81 for sediment load in the calibration period, respectively. During the validation period, the R 2 and NS were 0.93 and 0.80 for runoff, and 0.90 and 0.83 for sediment load respectively. The results showed that the model simulation was acceptable. Subsequently, the calibrated model was used to examine the effect of check dams on runoff and sediment load between 1990 and 2012. It showed that the increasing check dams contributed 24.8 and 27.7% to the decrease of annual runoff and sediment load during the period of 1990–1999, whereas it reached up to 65.2% for runoff decline and 78.3% for sediment load reduction within 2000–2012. Overall, this study illustrated a case study of the dominant role of check dams on variation of runoff and sediment load in the Huangfuchuan basin.

Analyses of trends and causes for variations in runoff and sediment load of the Yellow River

Due to the impacts of globe climate change and human activities, dramatic variations in runoff and sediment load were observed for the Yellow River. Analyses of nearly 65 years’ data measured at main hydrologic-stations on the Yellow River from 1950 to 2014 indicated that, except for the Tangnaihai station in the head region, sharp downward trends existed in both the annual runoff and annual sediment load according to the Mann–Kendal trend test; and their abrupt changes occurred in 1986 and in 1980, respectively, according to the rank sum test. Factors affecting the changes in the runoff and sediment load were very complicated. Results indicated that the reducing precipitation and the increasing water consumption were the main causes for the runoff decline, while the impoundment of the Longyangxia Reservoir and its combined operation with the Liujiaxia Reservoir exerted a direct bearing on the abrupt change in the annual runoff. In addition to the sediment load decrease associated with the runoff reduction, the reduced storm intensity, the conducted soil erosion control, and the constructed dam buildings all played an important role in the trends and abrupt changes of sediment load decline.

Many-year variations in river delta structures

Data on several river deltas are used to analyze the regularities in their dynamics in the context of variations of water and sediment runoff, sea level, and hydroengineering activities in delta areas. The basis for this analysis includes the results of many-year studies of river deltas in Russia and the world. The specific features of the evolution of the structure and morphometry of bayhead deltas, forming in bays, lagoons, and estuaries are shown in the case of the Alikazgan delta in the Terek mouth area and the deltas of two watercourses in the Mississippi mouth area. Data on many-year variations of the morphometric characteristics of modern protruding deltas in open coastal zones are systematized, and the factors that have an effect on these changes are analyzed. The types of delta formation processes and the types of deltas are considered with regard to the factors involved. The majority of modern river deltas are found to slow down their progradation into seas under the effect of anthropogenic runoff decline; moreover, some deltas have started retreating and degrading.

Attribution of Runoff Decline in the Amu Darya River in Central Asia during 1951–2007

Abstract Runoff in the Amu Darya River (ADR) in central Asia has been declining steadily since the 1950s. The reasons for this decline are ambiguous, requiring a complete analysis of glaciohydrological processes across the entire data-scarce source region. In this study, grid databases of precipitation from the Asian Precipitation–Highly Resolved Observational Data Integration Toward Evaluation of Water Resources (APHRODITE) and temperature from Princeton’s Global Meteorological Forcing Dataset (PGMFD) are used to force the distributed, glacier-enhanced Soil and Water Assessment Tool (SWAT) model to simulate glaciohydrological processes for 1951–2007 so as to determine long-term streamflow changes and the primary driving factors in the source region of the ADR. The study suggests that the database was a suitable proxy for temperature and precipitation forcing in simulating glaciohydrological processes in the data-scarce alpine catchment region. The estimated annual streamflow of 72.6 km3 in the upper ADR had a decreasing trend for the period from 1951 to 2007. Change in precipitation, rather than in temperature, dominated the decline in streamflow in either the tributaries or mainstream of the ADR. The streamflow decreased by 15.5% because of the decline in precipitation but only increased by 0.2% as a result of the increase in temperature. Thus, warming temperature had much less effect than declining precipitation on streamflow decline in the ADR in central Asia in 1951–2007.

Using hydrologic simulation to identify contributions of climate change and human activity to runoff changes in the Kuye river basin, China

Under the background of global climate change and local anthropogenic stresses, runoff has been in decline in most river basins in China over the past decades. Assessing the relative effect of climate change and human activities is essential not only for understanding the mechanism of hydrological response in the catchment, but also for local water resources management. The Kuye river, the first-order tributary of the middle Yellow river, has experienced significant runoff declines. In this study, the characteristics of hydro-climatic changes of the Kuye river catchment were analyzed based on the observed data for the period 1955–2010. Using the monthly climatic and hydrological data, the Yellow river water balance model (YRWBM) is calibrated and verified to a baseline period from 1955 to 1978. Subsequently, natural runoff for human-induced period (1979–1998) and strongly human-induced period (1999–2010) is reconstructed using the YRWBM model without considering local human impacts. Results indicate that the time series of runoff was divided into three periods at two critical years of 1979 and 1998. The YRWBM model performed well in simulating monthly discharges in the catchment, both NSES in calibration and verification were above 70 %, while RES in both periods were at less than 5 %. The absolute runoff reductions induced by climate change and human activities both have been growing. The percentage of runoff reduction attributed to climate variations from 60.56 % in human-induced periods to 43.50 % in strongly human-induced periods. At the same time the percentage of runoff reduction from human activities is from 39.44 % in human-induced periods to 56.50 % in strongly human-induced periods. Thus human activities demonstrated a dominant influence upon runoff decline gradually.

Attribution analysis for runoff decline in Yellow River Basin during past fifty years based on Budyko hypothesis

Here 38 sub-catchments in Yellow River Basin have been selected to explore the driving factors for runoff decline in this region. Climate elasticity and landscape elasticity which indicate the sensitivity of runoff to climate and landscape change are calculated based on the catchment water-energy balance equation. Furthermore, we quantify the effect of climate and landscape change on mean annual water yield. Results show that the distribution of climate elasticity is consistent with landscape elasticity and regions with highest sensitivity is located in the Loess Plateau. The annual runoff had statistically negative trends in most study sub-catchments. Landscape change is the dominant forcing factor for runoff decline in most study sub-catchments, specially in the Loess Plateau. By the analysis of NDVI (Normalized Difference Vegetation Index) during recent thirty years, we find that the improvement of vegetation is the dominant changes in landscape. This research indicates that it is a effective and promising application approach to quantify the effect of climate and landscape change on annual water yield based on the catchment water-energy balance equation.

Rainfall and runoff regime trends in mountain catchments (Case study area: the upper Hron River basin, Slovakia)

Abstract This paper presents an analysis of trends and causes of changes of selected hydroclimatic variables influencing the runoff regime in the upper Hron River basin (Slovakia). Different methods for identifying trends in data series are evaluated and include: simple mass curve analysis, linear regression, frequency analysis of flood events, use of the Indicators of Hydrological Alteration software, and the Mann-Kendall test. Analyses are performed for data from two periods (1931-2010 and 1961-2010). The changes in runoff are significant, especially in terms of lower QMax and 75 percentile values. This fact is also confirmed by the lower frequency and extremity of flood events. The 1980s are considered a turning point in the development of all hydroclimatic variables. The Mann-Kendall test shows a significant decrease in runoff in the winter period. The main causes of runoff decline are: the considerable increase in air temperature, the decrease in snow cover depth and changes in seasonal distribution of precipitation amounts.

Driving factors for runoff decline in the Upper Hanjiang basin, a major water source for the South-to-North Water Diversion Project in China

Abstract. With dramatic changes in climate and land-cover patterns around the world, it is of great significance to evaluate the corresponding influence on runoff change as water resources have become a strategic resource. We analysed the runoff change driven by landscape change and climate variation in Hanjiang River basin, which is the water source area of the central route of the South-to-North Water Diversion Project in China. Results show that the runoff decreased greatly from 1960 to 2012 in all the six selected sub-catchments. Attribution analysis results show that reduction of precipitation contributed to the catchment runoff decrease by 39.5–64.9% and landscape change, represented by increase of the parameter in the mathematical Budyko function contributed to the runoff decrease by 34.4–63.3%, while potential evapotranspiration change had a slightly negative contribution. In addition, the contribution is spatially variable from downstream to upstream. We conclude with a qualitative description about how water availability changes under changing landscape and climate conditions, and focus on the impact of vegetation cover change.

Different land management measures and climate change impacts on the runoff – A simple empirical method derived in a mesoscale catchment on the Loess Plateau

Large-scale vegetation restoration and climate change triggered a significant decline in runoff in the middle reaches of the Yellow River and its tributaries. This runoff decline intensifies inherent water shortage and results in more severe water use conflicts that are threatening sustainable development in the Loess Plateau. Innovative strategies for more water-efficient land management are essential. To this end, the factors controlling runoff were investigated using the upstream area of the Jing River as an example. Runoff was found to be mainly controlled by evaporative demand, precipitation, and land cover type. Budyko's frameworks were applied to predict the annual and long-term runoff; however, the effect of changes in land management (e.g., afforestation) on runoff cannot be assessed due to lack of vegetation factors. Therefore, an empirical analysis tool was derived based on an existing relationship for runoff estimation. This method was found to be more effective in reproducing the annual and long-term runoff than others. The incorporation of temporal changes in land cover and form in approach enables the estimation of the possible impact of soil conservation measures (e.g., afforestation or terracing). Our study highlights the importance of adaptive land management strategies for mitigating water shortage on the Loess Plateau.

Effects of Climate Change and Human Activities on Surface Runoff in the Luan River Basin

Quantifying the effects of climate change and human activities on runoff changes is the focus of climate change and hydrological research. This paper presents an integrated method employing the Budyko-based Fu model, hydrological modeling, and climate elasticity approaches to separate the effects of the two driving factors on surface runoff in the Luan River basin, China. The Budyko-based Fu model and the double mass curve method are used to analyze runoff changes during the period 1958~2009. Then two types of hydrological models (the distributed Soil and Water Assessment Tool model and the lumped SIMHYD model) and seven climate elasticity methods (including a nonparametric method and six Budyko-based methods) are applied to estimate the contributions of climate change and human activities to runoff change. The results show that all quantification methods are effective, and the results obtained by the nine methods are generally consistent. During the study period, the effects of climate change on runoff change accounted for 28.3~46.8% while those of human activities contributed with 53.2~71.7%, indicating that both factors have significant effects on the runoff decline in the basin, and that the effects of human activities are relatively stronger than those of climate change.