SWAT model-based quantification of the impact of land-use change on forest-regulated water flow

The intense climate changes and human activities have a great impact on the variation of the runoff of the coastal area of South China. In this work, the Soil and Water Assessment Tool (SWAT) is used to quantify the impact of land use and climate change of the Nanliujiang catchment on the runoff by setting 4 scenarios of land-use and climate change. The results show the runoff of the simulated and measured values had a similar trend. The value of relevant coefficient is above 0.8, and the value of Nash-Sutcliffe efficiency coefficient is about 0.8, which indicate that the SWAT model is fit for the study area. The annual average runoff depth during the period from 1995 to 2013 has increased by 53.5mm, of which the land use change resulted in 13.0mm increase on the annual average runoff depth while the climate change resulted in 40.9mm increase on the annual average runoff depth, therefore, the climate change has greater effect then the land use change. This work will delineate some helpful information for the water resources management as well as ecological protection in the coastal area of South China.

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Relative Importance of Land Use and Climate Change on Hydrology in Agricultural Watershed of Southern China

Sustainability ◽

10.3390/su12166423 ◽

2020 ◽

Vol 12 (16) ◽

pp. 6423

Author(s):

Lanhua Luo ◽

Qing Zhou ◽

Hong S. He ◽

Liangxia Duan ◽

Gaoling Zhang ◽

...

Keyword(s):

Climate Change ◽

Land Use ◽

Land Use Change ◽

River Basin ◽

Laboratory Experiments ◽

Southern China ◽

Swat Model ◽

Efficiency Coefficient ◽

Soil Database ◽

The Impact

Quantitative assessment of the impact of land use and climate change on hydrological processes is of great importance to water resources planning and management. The main objective of this study was to quantitatively assess the response of runoff to land use and climate change in the Zhengshui River Basin of Southern China, a heavily used agricultural basin. The Soil and Water Assessment Tool (SWAT) was used to simulate the river runoff for the Zhengshui River Basin. Specifically, a soil database was constructed based on field work and laboratory experiments as input data for the SWAT model. Following SWAT calibration, simulated results were compared with observed runoff data for the period 2006 to 2013. The Nash-Sutcliffe Efficiency Coefficient (NSE) and the correlation coefficient (R2) for the comparisons were greater than 0.80, indicating close agreement. The calibrated models were applied to simulate monthly runoff in 1990 and 2010 for four scenarios with different land use and climate conditions. Climate change played a dominant role affecting runoff of this basin, with climate change decreasing simulated runoff by −100.22% in 2010 compared to that of 1990, land use change increasing runoff in this basin by 0.20% and the combination of climate change and land use change decreasing runoff by 60.8m3/s. The decrease of forestland area and the corresponding increase of developed land and cultivated land area led to the small increase in runoff associated with land use change. The influence of precipitation on runoff was greater than temperature. The soil database used to model runoff with the SWAT model for the basin was constructed using a combination of field investigation and laboratory experiments, and simulations of runoff based on that new soil database more closely matched observations of runoff than simulations based on the generic Harmonized World Soil Database (HWSD). This study may provide an important reference to guide management decisions for this and similar watersheds.

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Analyzing the impacts of climate and land use changes on the water quality in the 3S river basin

Science and Technology Development Journal - Natural Sciences ◽

10.32508/stdjns.v2i2.745 ◽

2019 ◽

Vol 2 (2) ◽

pp. 125-131

Author(s):

Loi Thi Pham ◽

Khoi Nguyen Dao

Keyword(s):

Climate Change ◽

Water Quality ◽

Land Use ◽

Water Resources ◽

Land Use Change ◽

River Basin ◽

Water Resource Management ◽

Hydrological Modeling ◽

Swat Model ◽

The Impact

Assessing water resources under the influence of environmental change have gained attentions of scientists. The objective of this study was to analyze the impacts of land use change and climate change on water resources in terms quantity and quality in the 3S basin in the period 1981–2008 by using hydrological modeling (SWAT model). The results showed that streamflow and water quality (TSS, T-N, and T-P) tend to increase under individual and combined effects of climate change and land use change. In addition, the impact of land use change on the flow was smaller than the climate change impact. However, water balance components and water quality were equally affected by two factors of climate change and land use change. In general, the results of this study could serve as a reference for water resource management and planning in the river basin.

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Impacts of land use changes and climate variability on transboundary Hirmand River using SWAT

Journal of Water and Climate Change ◽

10.2166/wcc.2019.100 ◽

2019 ◽

Vol 11 (4) ◽

pp. 1695-1711 ◽

Cited By ~ 1

Author(s):

Mohammadreza Hajihosseini ◽

Hamidreza Hajihosseini ◽

Saeed Morid ◽

Majid Delavar ◽

Martijn J. Booij

Keyword(s):

Land Use ◽

Water Resources ◽

Land Use Change ◽

Environmental Changes ◽

Swat Model ◽

Land Use Changes ◽

River Basins ◽

Irrigated Area ◽

The Impact ◽

Annual Discharge

Abstract Many river basins are facing a reduction of flows which might be attributed to changes in climate and human activities. This issue is very important in transboundary river basins, where already existing conflicts about shared water resources between riparian countries can easily escalate. The decrease of streamflow in the transboundary Hirmand (Helmand) River is one of the main challenges for water resources management in Iran and Afghanistan. This research aims to quantify the causes of this problem which has a direct impact on the dryness of the Hamoun wetlands being an international Ramsar site. To achieve this, the land use changes in the Middle Helmand Basin (MHB) in Afghanistan were evaluated for three time periods between 1990 and 2011 using remote sensing data and the Soil and Water Assessment Tool (SWAT) Model for understanding watershed response to environmental changes. It was concluded that the total irrigated area in the region has increased from 103,000 ha in 1990 to 122,000 ha in 2001 and 167,000 ha in 2011 (62% increase). According to the results, the average annual discharge when adapting the land use during the simulations was 4,787 million cubic meters (MCM)/year and while employing the land use of 1990 from the beginning of the simulations, the average annual discharge was 5,133 MCM/year. Therefore, the agricultural developments in the Helmand basin decreased the discharge with about 346 MCM/year accompanying an increase of 64,000 ha in an irrigated area in MHB after 1990. Notably, the impact of land use change increases significantly for more recent periods and causes a reduction of 810 MCM in annual streamflow for the MHB. The amount of water depletion (i.e. actual evapotranspiration) per hectare has increased from 5,690 in 1985 to 7,320 m3 in 2012. The applied methodology of this study is useful to cope with such a data scarcity region. It can help quantify the impact of land use change on the region and formulates strategies that can improve the situation between Iran and Afghanistan.

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Modeling the Impact of Land Use Change on Basin‐scale Transfer of Fecal Indicator Bacteria: SWAT Model Performance

Journal of Environmental Quality ◽

10.2134/jeq2017.11.0456 ◽

2018 ◽

Vol 47 (5) ◽

pp. 1115-1122 ◽

Cited By ~ 6

Author(s):

Minjeong Kim ◽

Laurie Boithias ◽

Kyung Hwa Cho ◽

Oloth Sengtaheuanghoung ◽

Olivier Ribolzi

Keyword(s):

Land Use ◽

Land Use Change ◽

Fecal Indicator Bacteria ◽

Swat Model ◽

Model Performance ◽

Indicator Bacteria ◽

Fecal Indicator ◽

Basin Scale ◽

The Impact

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A Model-Based Tool for Assessing the Impact of Land Use Change Scenarios on Flood Risk in Small-Scale River Systems—Part 1: Pre-Processing of Scenario Based Flood Characteristics for the Current State of Land Use

Hydrology ◽

10.3390/hydrology8030102 ◽

2021 ◽

Vol 8 (3) ◽

pp. 102

Author(s):

Frauke Kachholz ◽

Jens Tränckner

Keyword(s):

Land Use ◽

River Flow ◽

Land Use Changes ◽

Small Rivers ◽

Small Scale ◽

Model Parameters ◽

Ungauged Catchments ◽

Model Based ◽

Current State ◽

The Impact

Land use changes influence the water balance and often increase surface runoff. The resulting impacts on river flow, water level, and flood should be identified beforehand in the phase of spatial planning. In two consecutive papers, we develop a model-based decision support system for quantifying the hydrological and stream hydraulic impacts of land use changes. Part 1 presents the semi-automatic set-up of physically based hydrological and hydraulic models on the basis of geodata analysis for the current state. Appropriate hydrological model parameters for ungauged catchments are derived by a transfer from a calibrated model. In the regarded lowland river basins, parameters of surface and groundwater inflow turned out to be particularly important. While the calibration delivers very good to good model results for flow (Evol =2.4%, R = 0.84, NSE = 0.84), the model performance is good to satisfactory (Evol = −9.6%, R = 0.88, NSE = 0.59) in a different river system parametrized with the transfer procedure. After transferring the concept to a larger area with various small rivers, the current state is analyzed by running simulations based on statistical rainfall scenarios. Results include watercourse section-specific capacities and excess volumes in case of flooding. The developed approach can relatively quickly generate physically reliable and spatially high-resolution results. Part 2 builds on the data generated in part 1 and presents the subsequent approach to assess hydrologic/hydrodynamic impacts of potential land use changes.

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Dynamics of soil organic carbon in the steppes of Russia and Kazakhstan under past and future climate and land use

Regional Environmental Change ◽

10.1007/s10113-021-01799-7 ◽

2021 ◽

Vol 21 (3) ◽

Author(s):

Susanne Rolinski ◽

Alexander V. Prishchepov ◽

Georg Guggenberger ◽

Norbert Bischoff ◽

Irina Kurganova ◽

...

Keyword(s):

Climate Change ◽

Land Use ◽

Organic Carbon ◽

Land Use Change ◽

Soil Organic Carbon ◽

Arable Land ◽

Future Climate ◽

Future Climate Change ◽

Climate Scenarios ◽

The Impact

AbstractChanges in land use and climate are the main drivers of change in soil organic matter contents. We investigated the impact of the largest policy-induced land conversion to arable land, the Virgin Lands Campaign (VLC), from 1954 to 1963, of the massive cropland abandonment after 1990 and of climate change on soil organic carbon (SOC) stocks in steppes of Russia and Kazakhstan. We simulated carbon budgets from the pre-VLC period (1900) until 2100 using a dynamic vegetation model to assess the impacts of observed land-use change as well as future climate and land-use change scenarios. The simulations suggest for the entire VLC region (266 million hectares) that the historic cropland expansion resulted in emissions of 1.6⋅ 1015 g (= 1.6 Pg) carbon between 1950 and 1965 compared to 0.6 Pg in a scenario without the expansion. From 1990 to 2100, climate change alone is projected to cause emissions of about 1.8 (± 1.1) Pg carbon. Hypothetical recultivation of the cropland that has been abandoned after the fall of the Soviet Union until 2050 may cause emissions of 3.5 (± 0.9) Pg carbon until 2100, whereas the abandonment of all cropland until 2050 would lead to sequestration of 1.8 (± 1.2) Pg carbon. For the climate scenarios based on SRES (Special Report on Emission Scenarios) emission pathways, SOC declined only moderately for constant land use but substantially with further cropland expansion. The variation of SOC in response to the climate scenarios was smaller than that in response to the land-use scenarios. This suggests that the effects of land-use change on SOC dynamics may become as relevant as those of future climate change in the Eurasian steppes.

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