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

We present results from the OP3 campaign in Sabah during 2008 that allow us to study the impact of local emission changes over Borneo on atmospheric composition at the regional and wider scale. OP3 constituent data provide an important constraint on model performance. Treatment of boundary layer processes is highlighted as an important area of model uncertainty. Model studies of land-use change confirm earlier work, indicating that further changes to intensive oil palm agriculture in South East Asia, and the tropics in general, could have important impacts on air quality, with the biggest factor being the concomitant changes in NO x emissions. With the model scenarios used here, local increases in ozone of around 50 per cent could occur. We also report measurements of short-lived brominated compounds around Sabah suggesting that oceanic (and, especially, coastal) emission sources dominate locally. The concentration of bromine in short-lived halocarbons measured at the surface during OP3 amounted to about 7 ppt, setting an upper limit on the amount of these species that can reach the lower stratosphere.

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Dynamic Land Use Change Prediction and Analysis of Its Impacts on Streamflow for Dabus Watershed, Upper Blue Nile Basin

10.20944/preprints202104.0393.v1 ◽

2021 ◽

Author(s):

Neseredin Bashawal Mangel ◽

Fitsum Berhe

Keyword(s):

Land Use ◽

Land Use Change ◽

Swat Model ◽

Model Performance ◽

Test Analysis ◽

Blue Nile Basin ◽

The Future ◽

Kappa Value ◽

Change Prediction ◽

Basin System

Based on the recorded watershed characteristics, the future conditions on the basin system can be predicted using a different method. In this study, dynamic land-use change and its impacts on the streamflow for the Dabus watershed were predicted using ANN-CA based method. The model performance for accurate prediction of the future land-use change on the Dabus River watershed has been checked by validation of the simulated value with the actual value, hence the overall kappa value (k) = 0.83 for the simulated 2016-LULC validated with actual 2016-LULC. Then, 2026-LULC was predicted based on the 2004 and 2009-LULC. The streamflow for the case of 2004 and 2009-LULC has been simulated using the SWAT model. The value of NSE = 0.87 and 0.90 was attained during validation of simulated streamflow for 2004 and 2009-LULC data cases, respectively. The agreement of simulated value of streamflow with the observed data is indicated as R2 = 0.91 and 0.96 for 2004-LULC and 2009-LULC. The effects of the dynamic land-use change on streamflow for the predicted land use(2026-LULC) catchment were evaluated by T-test analysis. Hence, T-stat =0.04 and -0.002 in the case of simulated streamflow used 2004-LULC and 2009-LULC, respectively compared with simulated value using 2026-LULC.

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APPLICATION OF SWAT MODEL IN ASSESSING THE IMPACT OF LAND USE CHANGE IN RUNOFF OF MAROON RIVER IN IRAN

Applied Ecology and Environmental Research ◽

10.15666/aeer/1605_54815502 ◽

2018 ◽

Vol 16 (5) ◽

pp. 5481-5502

Author(s):

K SHAFIEI MOTLAGH ◽

J PORHEMMAT ◽

H SEDGHI ◽

M HOSSENI

Keyword(s):

Land Use ◽

Land Use Change ◽

Swat Model ◽

The Impact ◽

Maroon River

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Impact of changes in land use and climate on the Runoff in the coastal areas of South China—A case study of the Nanliujiang catchment

MATEC Web of Conferences ◽

10.1051/matecconf/201824602001 ◽

2018 ◽

Vol 246 ◽

pp. 02001

Author(s):

Mingzhi Yang ◽

Weihua Xiao ◽

Yong Zhao ◽

Ya Huang ◽

Baoqi Li ◽

...

Keyword(s):

Climate Change ◽

Land Use ◽

Land Use Change ◽

South China ◽

Coastal Area ◽

Swat Model ◽

Efficiency Coefficient ◽

Annual Average ◽

Runoff Depth ◽

The Impact

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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Temporal-Spatial Variations and Influencing Factor of Land Use Change in Xinjiang, Central Asia, from 1995 to 2015

Sustainability ◽

10.3390/su11030696 ◽

2019 ◽

Vol 11 (3) ◽

pp. 696 ◽

Cited By ~ 3

Author(s):

Qun Liu ◽

Zhaoping Yang ◽

Cuirong Wang ◽

Fang Han

Keyword(s):

Land Use ◽

Land Use Change ◽

Central Asia ◽

Influencing Factor ◽

Land Use Changes ◽

Spatial Variations ◽

Water Bodies ◽

Unused Land ◽

Basin Scale ◽

The Impact

In this study, we analyzed the temporal-spatial variations of the characteristics of land use change in central Asia over the past two decades. This was conducted using four indicators (change rate, equilibrium extent, dynamic index, and transfer direction) and a multi-scale correlation analysis method, which explained the impact of recent environmental transformations on land use changes. The results indicated that the integrated dynamic degree of land use increased by 2.2% from 1995 to 2015. The areas of cropland, water bodies, and artificial land increased, with rates of 1047 km2/a, 39 km2/a, and 129 km2/a, respectively. On the other hand, the areas of forest, grassland, and unused land decreased, with rates of 54 km2/a, 803 km2/a, and 359 km2/a, respectively. There were significant increases in cropland and water bodies from 1995 to 2005, while the amount of artificial land significantly increased from 2005 to 2015. The increased areas of cropland in Xinjiang were mainly converted from grassland and unused land from 1995 to 2015, while the artificial land increase was mainly a result of the conversion from cropland, grassland, and unused land. The area of cropland rapidly expanded in south Xinjiang, which has led to centroid position to move cropland in Xinjiang in a southwest direction. Economic development and the rapid growth of population size are the main factors responsible for the cropland increases in Xinjiang. Runoff variations have a key impact on cropland changes at the river basin scale, as seen in three typical river basins.

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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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