Impact of Land Use and Landscape Patterns on Water Quality in Kaidu River
Understanding the influence of land use and landscape on river water quality in arid regions is crucial for maintaining ecological security.In this study,Kaidu River was selected for a case study,and we investigated the impact of land use and landscape on water quality in the river using BIOENV and re-dundancy analysis(RDA),aiming to provide a theoretical reference for water quality management in riv-ers in arid regions.The study was based on a water quality investigation at 15 sampling sites along the up-per,middle and lower reaches of Kaidu River in 2021 during the wet and dry seasons.Based on remote sensing images of the Kaidu River basin in 2020,land use data of circular buffer regions around the sam-pling points at five scales(200 m,500 m,1 000 m,2 000 m,5 000 m)were generated as water quality re-sponse units,and the land use structure was characterized by the proportion of different land use types in the watershed.The landscape pattern indices at each of the five spatial scales were extracted to character-ize the landscape pattern.Results show that:(1)Water quality of Kaidu River was clean or relatively clean at each sampling site,and water quality in the dry season was slightly better than that in the wet season.(2)Land use in the buffer zones at 2 000 m and 5 000 m scales explained water quality well during both the wet and seasons,with explanation rates of 63.81％and 64.91％,respectively.The landscape within the 500 m and 200 m circular buffer zones had the strongest explanatory power for water quality,with expla-nation rates of 73.88％and 63.33％,respectively.(3)During the wet season,the contribution rates of crop-land(57.9％)and the largest patch index(LPI:48.8％)for water quality was highest,while the land use type and landscape index with the highest contribution rates to water quality in dry season was grassland(68％)and landscape shape index(LSI:21.6％).(4)During the wet season,the combination of cropland,woodland and water had the highest correlation coefficients(0.424 5)with water quality,and the highest correlation coefficient in dry season was 0.512 9 between grassland and water quality.The combination of landscape indices(NP,LPI,and ENN_MN)had the highest correlation coefficient(0.076 5)with water qual-ity in wet season,and the highest correlation coefficient in dry season was 0.216 3 between the combina-tion of landscape indices(NP,PD,and LPI)and water quality.(5)The explanatory power of the interac-tion between land use structure and landscape pattern on water quality was 18％within the 2 000 m circu-lar buffer zone during the wet season,higher than the 11％within the 200 m circular buffer zone during the dry season.These results show that both land use structure and landscape pattern have large impacts on water quality in Kaidu River,and their interaction plays an even larger role.
万方数据
维普
