Diverse impacts of land use on water quality at the spatial and temporal scale between fluvial lakes and volcanic lakes in Southwest China
This study aimed to investigate the diverse impacts of land use on water quality of different lake types at different spatial and temporal scales.For this purpose,landscape pattern indices were extracted at six spatial scales(50,60,70,80,90,100 m lakeshore buffer zones)from Fushun West Lake(fluvial lake)in Zigong City,Sichuan Province,and Qinghai Lake(volcanic lake)in Tengchong City,Yunnan Province.The data were combined with the water quality data in wet-season(July 2022)and dry-season(April 2023)periods.Redundancy analysis was used to quantitatively investigate the differences in the impacts of land use on water quality of the two types of lakes at different spatial and temporal scales.The results showed that:(1)Fushun West Lake and Qinghai Lake had significant seasonal variations in water quality.Water quality is better in wet season than that in dry season.There was a significant difference in the water quality of these two lakes.The water quality of Qinghai Lake was better than that of Fushun West Lake.Qinghai Lake conformed to the class Ⅱ and Ⅲ standards of water quality of the surface water environ-ment,and Fushun West Lake reached the standards of water quality of class Ⅳ and Ⅴ.(2)The land use of Fushun West Lake had the strongest impact on water quality during the dry season at the 50-60 m lakeshore buffer zone scale.However,the land use of Lake Qinghai had the highest interpretation rate for water quality during the wet season at the 60 m lakeshore buffer zone scale.(3)The impact of land use indices on the water quality of the two types lakes was different.Patch index,landscape shape index and ag-gregation index were positively correlated with most of the water quality indicators in the Fushun West Lake watershed.The high de-gree of aggregation and fragmentation of the"source"landscapes would exacerbate the threat to water quality.The proportion of for-est land area and the aggregation index within Qinghai Lake watershed had a positive effect on water quality,which can improve water quality.An increase in patch index and landscape shape index values exacerbated the fragmentation of the patches and led to deterioration of water quality.Based on different spatial and temporal scales,this study explored the relationship between land use and water quality of two types of lakes.It would potentially support the regional planning and management of different types of lakes,and provide a scientific basis for the evaluation of the lake water quality and lake protection,as well as for the development of targeted lake buffer zones and ecological restoration strategies,so as to promote the safety of the water quality of the lakes and the sustainable use of water resources.
Land usewater qualitymulti-scale effectsredundancy analysissouthwestern lakes
万方数据
维普
