| The land surface change and climate change are two main aspects of the enviornment change,which has resulted in water resources change.Therefore,study on the effect of environmental change on regional water cycle and water resources evolution has not only important scientific support value to alleviate and adapt to enviornment change,but also important practical significance for the water resource management.In this thesis,the upstream of Pianjiakou reservoir in Luanhe river basin was taken as the study area.The temporal and spatial varation of hydrological components was analyzed.Multiple-regression model and the SWAT distributed hydrological model was utilized to study the impacts of land surface change and climate change on the water resources,respectively.The main conclusions and innovations are summarized as follows:(1)The Mann-Kendall test and the moving average method were used to analyze the trend of temperature and precipitation,the statistical method was used to analyze the characteristics of temperature and precipitation in annual and interannual variation.The result showed that the annual average temporature has a upward trend in 1957-2010,the significant periodic varation of temperature within a year,and a large difference of the average temperature in each month.The annual average precipitation showed a decreasing trend in 1957-2010,and the precipitation distribution has obvious seasonal change.(2)The comprehensive land use degree index,the spatial and temporal evolution model,transfer matrix,dynamic model and the spatial analysis model were utilized to analyze the characteristics and land use change in the study area.The results showed that the years of 1970-1980 and 1980-2000 were in a developed period,but the land use was in a recession after 2000 by the land use degree composite index and spatial temporal evoluation model.And from the result caculated by dynamic model,the result showed that the transformation between the land use types was most frequent in 2000-2004.(3)Based on the interpretation of the NCEP and the reanalysis data,the water vapor content and the vapor flux from 1948-2010 in Haihe river basin and Luanhe river baisn were estimated.The linear moving average and the linear trend regression method were used to study the spatial and temporal variations of water vapor content and the vapor flux in the Haihe and Luanhe river basin.According to the caculation,it can be seen that the annual average moisture content is obviously,although it fluctuated,a downward trend.The propotion of water vapor content in the whole year was 19.31% in spring,50.33% in summer,22.91% in autumn and 7.45% in winter.The results showed that the trend of the water vapor flux is simliar to that of the vapor content in Luanhe river basin.But the moisture transport is predominantly zonal and only to a slight extent meridional.(4)Considering the related characteristics of the precipitation and runoff in the upstream of Sandaohezi hydrological station,and on a basis of the observed monthly precipitation and runoff data in 1961-2010,we established the precipitation-runoff multiple regression models in dry season and rainny season,respectively.And after application of the models,we discussed the impacts of high and low variation of precipitation and the land surface change on the runoff.The results showed that under the same condition of land surface of 1961-1983 period,the runoff increased by 8.08% during the period of 1984-1999,and it reduced by 25.34% during 2000-2011,respectively,caused by precipitation variation.However,under the same condition of precipitation,the runoff reduced by 19.40% in the 1984-1999 period and 43.16% in the 2000-2011 period,respectively,because of land surface change.(5)A distributed hydrological model was built in Luanhe river basin,and the correlation coefficients were above 0.7 in the calibration and verification period.It meant that the the model had a good performance.Based on this model,the impacts of land use/land cover change on the runoff were analyzed.The results showed that arable land converted to forests,arable land converted to grassland and in the period of 2000-2004,which led to the runoff decrease by 58.55% on average.Therefore,in recent years,the land use/land cover change has great influence on the runoff in Luanhe river basin.(6)In order to discuss the response of runoff to climate change in Luan River Basin,climatic scenarios were set by analyzing the time series as well as assuming the change to drive the SWAT model.The results showed that under the scenario of the temperatue rise 1 oC or 2 oC,the rate of runoff change were-7.11% and-9.11%,respectively.When the average daily precipitation increased or decreased by 10%,the rate of runoff change were 17.56% and-33.03%,respectively.However,when the temperatue rised 1 oC or 2 oC,the average daily precipitation increased by 10%,the rate of runoff change were 15.17% and 13.19%,respectively.It meant that,the monthly runoff was more sensitive to precipitation;the effect of temperature was comparative less. |
PDF Full Text Request