The Changes And Driving Factors Analysis Of Hydrology-ecological Environment Of The Three-river Source Region

In recent years, with the national attention to the construction of ecological civilization and the increasing input, the ecological environment in the source region of Three river has changed a lot since the establishment of the nature reserve. The MOD13Q1 series provides the normalized difference vegetation index as indicators of source region hydrology ecological environment. Respectively from the point of view of time series and space series discussed source area hydrologic elements of the ecological environment changes, at the same time with the help from the statistical analysis method to promote these changes the driving factor for the qualitative and quantitative analysis. The main results are as follows:(1)The spatial and temporal distribution of rainfall in the source region of Three river is quite different. In time distribution, annual rainfall total and average temperature are changing with time showed rising trend, but the month distribution uneven, summer more precipitation and winter precipitation is low, runoff in flood season from May to October accounted for most of the annual total amount of runoff. In the spatial distribution, the rainfall in the southeast area is more than that in the northwest region.(2) The overall NDVI index in spatial distribution showed the characteristics of decreasing from the southeast to the northwest, and the average annual vegetation normalized index value of the three major river systems was also lower than that of the downstream region.Rainfall is time scales of Three river source area hydrologic changes in the ecological environment of the main driving factors,(3) in the time series, Three river region normalized difference vegetation index of rainfall response more strongly, and it was the main driving factor of the vegetation index change(4) Under the space sequence, the air temperature had a more significant impact on the hydrological ecological environment in the source region of Three river, and it was the main driving factor of the vegetation index change.(5) NDVI in the vicinity of the highway where the highway is located in the center, showing a high on both sides of the middle of the low distribution of the law, and the situation in the vicinity of the river is opposite. In time series, the values of NDVI near the river and the highway all increase with time.(6)By means of principal component analysis found that elevation, population, and drainage density of ecological environment in the source region of change has a higher contribution rate...