scholarly journals Modeling Land Use Changes and their Impacts on Non-Point Source Pollution in a Southeast China Coastal Watershed

2018 ◽  
Vol 15 (8) ◽  
pp. 1593 ◽  
Author(s):  
Xin Zhang ◽  
Lin Zhou ◽  
Yuqi Liu
Keyword(s):  
Land Use ◽  
Point Source ◽  
River Basin ◽  
Landscape Metrics ◽  
Land Use Changes ◽  
Landscape Patterns ◽  
Cultivated Land ◽  
Point Source Pollution ◽  
Coastal Watershed ◽  
Non Point Source Pollution

Changes in landscape patterns in a river basin play a crucial role in the change on load of non-point source pollution. The spatial distribution of various land use types affects the transmission of non-point source pollutants on the basis of source-sink theory in landscape ecology. Jiulong River basin in southeast of China was selected as the study area in this paper. Aiming to analyze the correlation between changing landscape patterns and load of non-point source pollution in this area, traditional landscape metrics and the improved location-weighted landscape contrast index based on the minimum hydrological response unit (HRULCI) were applied in this study, in combination with remote sensing and geographic information system (GIS) technique. The results of the landscape metrics showed the enhanced fragmentation extent and the decreasing polymerization degree of the overall landscape in the watershed. High values of HRULCI were concentrated in cultivated land, while low HRULCI values mostly appeared in forestland, indicating that cultivated land substantially enhanced non-point source pollution, while forestland inhibited the pollution process.

scholarly journals Spatial-Temporal Change of Land Use and Its Impact on Water Quality of East-Liao River Basin from 2000 to 2020

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1955
Author(s):  
Mingxi Zhang ◽  
Guangzhi Rong ◽  
Aru Han ◽  
Dao Riao ◽  
Xingpeng Liu ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Land Use Change ◽  
Point Source ◽  
Water Body ◽  
Forest Land ◽  
Point Source Pollution ◽  
Construction Land ◽  
Unused Land ◽  
Non Point Source Pollution

Land use change is an important driving force factor affecting the river water environment and directly affecting water quality. To analyze the impact of land use change on water quality change, this study first analyzed the land use change index of the study area. Then, the study area was divided into three subzones based on surface runoff. The relationship between the characteristics of land use change and the water quality grade was obtained by grey correlation analysis. The results showed that the land use types changed significantly in the study area since 2000, and water body and forest land were the two land types with the most significant changes. The transfer rate is cultivated field > forest land > construction land > grassland > unused land > water body. The entropy value of land use information is represented as Area I > Area III > Area II. The shift range of gravity center is forest land > grassland > water body > unused land > construction land > cultivated field. There is a strong correlation between land use change index and water quality, which can be improved and managed by changing the land use type. It is necessary to establish ecological protection areas or functional areas in Area I, artificial lawns or plantations shall be built in the river around the water body to intercept pollutants from non-point source pollution in Area II, and scientific and rational farming in the lower reaches of rivers can reduce non-point source pollution caused by farming.

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