Effects of climate change and land use change on runoff,sediment,nitrogen and phosphorus losses in the Haihe River Basin
The Haihe River Basin plays an important role in the sustainable economic develop-ment of the national economy and is also one of the most water-scare regions in China.Densely populated,long-term inappropriate human activities and climate change have exacerbated the problems of soil erosion and water scarcity in the region.Therefore,studying the effects of cli-mate change and land use on runoff,sediment,and nitrogen and phosphorus losses in the Haihe River Basin provides not only theoretical support for the early warning of water and sand haz-ards in the region,but also an important scientific basis for understanding the evolutionary pat-tern of the basin's ecological environment.In this study,we analyzed the spatial and temporal evolution patterns of climate,land use,evapotranspiration(ET),normalized vegetation index(NDVI),and net primary productivity(NPP)in the Haihe River Basin from 1985 to 2015 and their influence mechanisms.The results show that:(1)There are significant geographical differ-ences in the correlations among the variables(ET,NDVI,NPP,runoff,sediment,nitrogen and phosphorus,etc.)in the six sub-basins of the Haihe River Basin.(2)Temperature and precipita-tion directly affect runoff,and thus indirectly affect sediment and nitrogen and phosphorus loss-es.(3)ET is directly affected by both temperature and precipitation,and it directly affects run-off,and then indirectly affects sediment and nitrogen and phosphorus losses.The paper reveals the influence of climate and land use changes on runoff,sediment and nitrogen and phosphorus losses over the past 30 years,which is of great significance to the understanding of the evolu-tion of the ecological environment of the basin and its regulation.
Haihe River Basinland useclimate changeecohydrology
NETL
NSTL
万方数据
