scholarly journals Land Use and Climate Change Effects on Surface Runoff Variations in the Upper Heihe River Basin

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 344 ◽  
Author(s):  
Xingxing Shang ◽  
Xiaohui Jiang ◽  
Ruining Jia ◽  
Chen Wei
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Assessment Tool ◽  
Simulation Analysis ◽  
Change Scenario ◽  
Heihe River ◽  
Reference Period ◽  
Scenario Simulation ◽  
Contribution Rate ◽  
Ecological Protection

The runoff in the upper reaches of the Heihe River has been continuously abundant for more than a decade, and this has not happened previously in history. Quantitative analysis of runoff variation and its influencing factors are of great significance for the ecological protection of the basin. In this paper, the soil and water assessment tool model was used to simulate runoff in the study area, and the method of scenario simulation was used to quantitatively analyze the runoff response with respect to land use and climate change. According to the abruptness of the runoff sequence, the years before 2004 are categorized as belonging to the reference period, and after 2004 is categorized as the interference period. According to the analysis, compared with the reference period, the contribution rate of climate change is 87.15%, while the contribution rate of land use change is only 12.85%. The climate change scenario simulation analysis shows that the change in runoff is positively correlated with the change in precipitation. The relationship with the change in temperature is more complicated, but the influence of precipitation change is stronger than the change in temperature. According to the land use scenario simulation analysis, under the economic development scenario, the runoff decreased, whereas under the historical trend and ecological protection scenario, the runoff increased. Additionally, the runoff increased more under the ecological protection scenario.

scholarly journals A Review of SWAT Model Application in Africa

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1313
Author(s):  
George Akoko ◽  
Tu Hoang Le ◽  
Takashi Gomi ◽  
Tasuku Kato
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Water Resources ◽  
Hydrological Modeling ◽  
Assessment Tool ◽  
Swat Model ◽  
Data Availability ◽  
Mitigation Measures ◽  
Model Parameterization ◽  
Basin Scale

The soil and water assessment tool (SWAT) is a well-known hydrological modeling tool that has been applied in various hydrologic and environmental simulations. A total of 206 studies over a 15-year period (2005–2019) were identified from various peer-reviewed scientific journals listed on the SWAT website database, which is supported by the Centre for Agricultural and Rural Development (CARD). These studies were categorized into five areas, namely applications considering: water resources and streamflow, erosion and sedimentation, land-use management and agricultural-related contexts, climate-change contexts, and model parameterization and dataset inputs. Water resources studies were applied to understand hydrological processes and responses in various river basins. Land-use and agriculture-related context studies mainly analyzed impacts and mitigation measures on the environment and provided insights into better environmental management. Erosion and sedimentation studies using the SWAT model were done to quantify sediment yield and evaluate soil conservation measures. Climate-change context studies mainly demonstrated streamflow sensitivity to weather changes. The model parameterization studies highlighted parameter selection in streamflow analysis, model improvements, and basin scale calibrations. Dataset inputs mainly compared simulations with rain-gauge and global rainfall data sources. The challenges and advantages of the SWAT model’s applications, which range from data availability and prediction uncertainties to the model’s capability in various applications, are highlighted. Discussions on considerations for future simulations such as data sharing, and potential for better future analysis are also highlighted. Increased efforts in local data availability and a multidimensional approach in future simulations are recommended.

scholarly journals Relative impacts of land use and climate change on summer precipitation in the Netherlands

2016 ◽  
Vol 20 (10) ◽  
pp. 4129-4142 ◽  
Author(s):  
Emma Daniels ◽  
Geert Lenderink ◽  
Ronald Hutjes ◽  
Albert Holtslag
Keyword(s):  
Climate Change ◽  
Land Use ◽  
The Netherlands ◽  
Land Use Changes ◽  
Wrf Model ◽  
Summer Precipitation ◽  
Circulation Type ◽  
Weather Research And Forecasting ◽  
Temperature Perturbation ◽  
Change Scenario

Abstract. The effects of historic and future land use on precipitation in the Netherlands are investigated on 18 summer days with similar meteorological conditions. The days are selected with a circulation type classification and a clustering procedure to obtain a homogenous set of days that is expected to favor land impacts. Changes in precipitation are investigated in relation to the present-day climate and land use, and from the perspective of future climate and land use. To that end, the weather research and forecasting (WRF) model is used with land use maps for 1900, 2000, and 2040. In addition, a temperature perturbation of +1 °C assuming constant relative humidity is imposed as a surrogate climate change scenario. Decreases in precipitation of, respectively, 3–5 and 2–5 % are simulated following conversion of historic to present, and present to future, land use. The temperature perturbation under present land use conditions increases precipitation amounts by on average 7–8 % and amplifies precipitation intensity. However, when also considering future land use, the increase is reduced to 2–6 % on average, and no intensification of extreme precipitation is simulated. In all, the simulated effects of land use changes on precipitation in summer are smaller than the effects of climate change, but are not negligible.

scholarly journals Land Use/Cover Change Effects on River Basin Hydrological Processes Based on a Modified Soil and Water Assessment Tool: A Case Study of the Heihe River Basin in Northwest China’s Arid Region

2019 ◽  
Vol 11 (4) ◽  
pp. 1072 ◽  
Author(s):  
Xin Jin ◽  
Yanxiang Jin ◽  
Xufeng Mao
Keyword(s):  
Land Use ◽  
River Basin ◽  
Assessment Tool ◽  
River Basins ◽  
Climatic Conditions ◽  
Hydrological Processes ◽  
Heihe River ◽  
Distributed Models ◽  
The Subject ◽  
Increasing Trends

Land use/cover change (LUCC) affects canopy interception, soil infiltration, land-surface evapotranspiration (ET), and other hydrological parameters during rainfall, which in turn affects the hydrological regimes and runoff mechanisms of river basins. Physically based distributed (or semi-distributed) models play an important role in interpreting and predicting the effects of LUCC on the hydrological processes of river basins. However, conventional distributed (or semi-distributed) models, such as the soil and water assessment tool (SWAT), generally assume that no LUCC takes place during the simulation period to simplify the computation process. When applying the SWAT, the subject river basin is subdivided into multiple hydrologic response units (HRUs) based on the land use/cover type, soil type, and surface slope. The land use/cover type is assumed to remain constant throughout the simulation period, which limits the ability to interpret and predict the effects of LUCC on hydrological processes in the subject river basin. To overcome this limitation, a modified SWAT (LU-SWAT) was developed that incorporates annual land use/cover data to simulate LUCC effects on hydrological processes under different climatic conditions. To validate this approach, this modified model and two other models (one model based on the 2000 land use map, called SWAT 1; one model based on the 2009 land use map, called SWAT 2) were applied to the middle reaches of the Heihe River in northwest China; this region is most affected by human activity. Study results indicated that from 1990 to 2009, farmland, forest, and urban areas all showed increasing trends, while grassland and bare land areas showed decreasing trends. Primary land use changes in the study area were from grassland to farmland and from bare land to forest. During this same period, surface runoff, groundwater runoff, and total water yield showed decreasing trends, while lateral flow and ET volume showed increasing trends under dry, wet, and normal conditions. Changes in the various hydrological parameters were most evident under dry and normal climatic conditions. Based on the existing research of the middle reaches of the Heihe River, and a comparison of the other two models from this study, the modified LU-SWAT developed in this study outperformed the conventional SWAT when predicting the effects of LUCC on the hydrological processes of river basins.

scholarly journals Quantification of climate change and land cover/use transition impacts on runoff variations in the upper Hailar Basin, NE China

2020 ◽  
Vol 51 (5) ◽  
pp. 976-993
Author(s):  
Yuhui Yan ◽  
Baolin Xue ◽  
Yinglan A ◽  
Wenchao Sun ◽  
Hanwen Zhang
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
Precipitation Change ◽  
Climate Change Scenarios ◽  
Reference Period ◽  
Ne China ◽  
Runoff Change ◽  
Hailar Basin ◽  
The Impact

Abstract Quantification of runoff change is vital for water resources management, especially in arid or semiarid areas. This study used the Soil and Water Assessment Tool (SWAT) distributed hydrological model to simulate runoff in the upper reaches of the Hailar Basin (NE China) and to analyze quantitatively the impacts of climate change and land-use change on runoff by setting different scenarios. Two periods, i.e., the reference period (before 1988) and the interference period (after 1988), were identified based on long-term runoff datasets. In comparison with the reference period, the contribution rates of both climate change and land-use change to runoff change in the Hailar Basin during the interference period were 83.58% and 16.42%, respectively. The simulation analysis of climate change scenarios with differential precipitation and temperature changes suggested that runoff changes are correlated positively with precipitation change and that the impact of precipitation change on runoff is stronger than that of temperature. Under different economic development scenarios adopted, land use was predicted to have a considerable impact on runoff. The expansion of forests within the basin might induce decreased runoff owing to enhanced evapotranspiration.

scholarly journals Assessing the Impacts of Climate Change and Land Use/Cover Change on Runoff Based on Improved Budyko Framework Models Considering Arbitrary Partition of the Impacts

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1612
Author(s):  
Manling Xiong ◽  
Ching-Sheng Huang ◽  
Tao Yang
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Change Point ◽  
Extreme Values ◽  
Weighting Factor ◽  
Heihe River ◽  
Runoff Variation ◽  
Pettitt Test ◽  
The Impact ◽  
Impacts Of Climate Change

Various models based on Budyko framework, widely applied to quantify the impacts of climate change and land use/cover change (LUCC) on runoff, assumed a fixed partition used to distinguish the impacts. Several articles have applied a weighting factor describing arbitrary partitions for developing a total differential Budyko (TDB) model and a complementary Budyko (CB) model. This study introduces the weighting factor into a decomposition Budyko (DB) model and applies these three models to analyze runoff variation due to the impacts in the upper-midstream Heihe River basin. The Pettitt test is first applied to determine a change point of a time series expanded by the runoff coefficient. The cause for the change point is analyzed. Transition matrix is adopted to investigate factors of LUCC. Results suggest the consistency of the CB, TDB, and present DB models in estimating runoff variation due to the impacts. The existing DB model excluding the weighting factor overestimates the impact of climate change on runoff and underestimates the LUCC impact as compared with the present DB model. With two extreme values of the weighting factor, runoff decrease induced by LUCC falls in the range of 65.20%–66.42% predicted by the CB model, 65.01%–66.57% by the TDB model, and 64.83%–66.85% by the present DB model. The transition matrixes indicate the major factors of LUCC are climate warming in the upstream of the study area and cropping in the midstream. Our work provides researchers with a better understanding of runoff variation due to climate change and LUCC.

scholarly journals Assessing Impacts of Climate Variability and Reforestation Activities on Water Resources in the Headwaters of the Segura River Basin (SE Spain)

2018 ◽  
Vol 10 (9) ◽  
pp. 3277 ◽  
Author(s):  
Javier Senent-Aparicio ◽  
Sitian Liu ◽  
Julio Pérez-Sánchez ◽  
Adrián López-Ballesteros ◽  
Patricia Jimeno-Sáez
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Water Resources ◽  
River Basin ◽  
Assessment Tool ◽  
Forest Area ◽  
Se Spain ◽  
Monthly Streamflow ◽  
Agricultural Areas ◽  
Water Assessment

Climate change and the land-use and land-cover changes (LULC) resulting from anthropic activity are important factors in the degradation of an ecosystem and in the availability of a basin’s water resources. To know how these activities affect the quantity of the water resources of basins, such as the Segura River Basin, is of vital importance. In this work, the Soil and Water Assessment Tool (SWAT) was used for the study of the abovementioned impacts. The model was validated by obtaining a Nash–Sutcliffe efficiency (NSE) of 0.88 and a percent bias (PBIAS) of 17.23%, indicating that SWAT accurately replicated monthly streamflow. Next, land-use maps for the years of 1956 and 2007 were used to establish a series of scenarios that allowed us to evaluate the effects of these activities on both joint and individual water resources. A reforestation plan applied in the basin during the 1970s caused that the forest area had almost doubled, whereas the agricultural areas and shrubland had been reduced by one-third. These modifications, together with the effect of climate change, have led to a decrease of 26.3% in the quantity of generated water resources, not only due to climate change but also due to the increase in forest area.

CLIMATE- AND LAND USE-INDUCED RISKS TO WATERSHED SERVICES IN THE NYANDO RIVER BASIN, KENYA

2011 ◽  
Vol 47 (2) ◽  
pp. 339-356 ◽  
Author(s):  
MWANGI GATHENYA ◽  
HOSEA MWANGI ◽  
RICHARD COE ◽  
JOSEPH SANG
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
Sediment Yield ◽  
Land Surface ◽  
Assessment Tool ◽  
Surface Condition ◽  
Water Yield ◽  
Minor Effect ◽  
Watershed Services

SUMMARYClimate change and land use change are two forces influencing the hydrology of watersheds and their ability to provide ecosystem services, such as clean and well-regulated streamflow and control of soil erosion and sediment yield. The Soil Water Assessment Tool, SWAT, a distributed, watershed-scale hydrological model was used with 18 scenarios of rainfall, temperature and infiltration capacity of land surface to investigate the spatial distribution of watershed services over the 3587 km2 Nyando basin in Western Kenya and how it is affected by these two forces. The total annual water yield varied over the 50 sub-basins from 35 to 600 mm while the annual sediment yield ranged from 0 to 104 tons ha−1. Temperature change had a relatively minor effect on streamflow and sediment yield compared to change in rainfall and land surface condition. Improvements in land surface condition that result in higher infiltration are an effective adaptation strategy to moderate the effects of climate change on supply of watershed services. Spatial heterogeneity in response to climate and land use change is large, and hence it is necessary to understand it if interventions to modify hydrology or adapt to climate change are to be effective.

SWAT-based sediment yield simulation with mining land-use change scenario in Lanuza Bay, Philippines

2020 ◽  
Author(s):  
Peter Jeffrey Maloles ◽  
Adonis Gallentes ◽  
Cesar Villanoy
Keyword(s):  
Land Use ◽  
Sediment Yield ◽  
Assessment Tool ◽  
Marine Protected Area ◽  
Swat Model ◽  
Time Lag ◽  
The Philippines ◽  
Marine Biodiversity ◽  
Change Scenario ◽  
Mining Operations

<p>The Philippines is known for its rich marine biodiversity and is deemed as the apex of the world’s coral triangle. However, sediment yield studies and river discharge measurements in the country are sparse if not non-existent. High sediment rates have detrimental effects on water quality and consequently to coral reef health and marine biodiversity. Thus, modeling of runoff and sediment yield at a watershed level is important in assessing coral community environments.</p><p>In this study, a Soil and Water Assessment Tool (SWAT) based sediment yield simulation was done for Lanuza Bay-- a site with high productivity but increasing mining activity. Two simulations were conducted. The first utilized a land-use map before January 2011 and was made to run from January 1998 to August 2018 in order to simulate a scenario in which mining operations did not occur in the area. The second simulation utilized an updated land-use map that incorporated mining sites from January 2011 to August 2018.</p><p>SWAT model results indicate that slope class was the primary determinant of erosion rates (slope band > 20%). The study suggests that consecutive precipitation occurrences affected soil erodability and induced a time lag between precipitation and sediment yield peaks. The highest contributors to sediment yield at a sub-basin level were identified to be areas adjacent to or coinciding in mining or excavation sites. Comparing the scenarios with and without mining, mining contributed to 4% of the increase in the watershed’s total annual sediment yield.</p><p>Qualitative and historical validation shows reasonable agreement between simulated values and satellite images. The output of this study can be used as a science-based reference in crafting laws and policies for land-use management and Marine Protected Area (MPA) planning.</p>

scholarly journals Influence of future climate and cropland expansion on isoprene emissions and tropospheric ozone

2014 ◽  
Vol 14 (2) ◽  
pp. 1011-1024 ◽  
Author(s):  
O. J. Squire ◽  
A. T. Archibald ◽  
N. L. Abraham ◽  
D. J. Beerling ◽  
C. N. Hewitt ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
21St Century ◽  
Tropospheric Ozone ◽  
Climate Model ◽  
Anthropogenic Emissions ◽  
Change Scenario ◽  
Dynamic Global Vegetation Model ◽  
The Tropics

Abstract. Over the 21st century, changes in CO2 levels, climate and land use are expected to alter the global distribution of vegetation, leading to changes in trace gas emissions from plants, including, importantly, the emissions of isoprene. This, combined with changes in anthropogenic emissions, has the potential to impact tropospheric ozone levels, which above a certain level are harmful to animals and vegetation. In this study we use a biogenic emissions model following the empirical parameterisation of the MEGAN model, with vegetation distributions calculated by the Sheffield Dynamic Global Vegetation Model (SDGVM) to explore a range of potential future (2095) changes in isoprene emissions caused by changes in climate (including natural land use changes), land use, and the inhibition of isoprene emissions by CO2. From the present-day (2000) value of 467 Tg C yr−1, we find that the combined impact of these factors could cause a net decrease in isoprene emissions of 259 Tg C yr−1 (55%) with individual contributions of +78 Tg C yr−1 (climate change), −190 Tg C yr−1 (land use) and −147 Tg C yr−1 (CO2 inhibition). Using these isoprene emissions and changes in anthropogenic emissions, a series of integrations is conducted with the UM-UKCA chemistry-climate model with the aim of examining changes in ozone over the 21st century. Globally, all combined future changes cause a decrease in the tropospheric ozone burden of 27 Tg (7%) from 379 Tg in the present-day. At the surface, decreases in ozone of 6–10 ppb are calculated over the oceans and developed northern hemispheric regions, due to reduced NOx transport by PAN and reductions in NOx emissions in these areas respectively. Increases of 4–6 ppb are calculated in the continental tropics due to cropland expansion in these regions, increased CO2 inhibition of isoprene emissions, and higher temperatures due to climate change. These effects outweigh the decreases in tropical ozone caused by increased tropical isoprene emissions with climate change. Our land use change scenario consists of cropland expansion, which is most pronounced in the tropics. The tropics are also where land use change causes the greatest increases in ozone. As such there is potential for increased crop exposure to harmful levels of ozone. However, we find that these ozone increases are still not large enough to raise ozone to such damaging levels.

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