| For the last hundreds of years, the earth’s system is experiencing a significant change of warming as the main characteristics, which becomes one of the main global environmental problems for the international society. The middle reach of Yellow River is located in a transition zone from semi-humid to semi-arid area, with weak ecological environment, the maldistribution of underlying surface, and is one of ecologically fragile zone where is sensitive to global climate change. The article takes the three provinces of Jin, Shan, Yu in the middle reach of Yellow River as a study case, analyzes the six climate factors during1961～2010years, and the MODIS productions of NDVI (normalized difference vegetation index), LAI(leaf area index), LST(land surface temperature), surface ALBEDO, and soil moisture, altitude for land surface parameters. The temporal and spatial characteristics of regional climate change and the correlation with land surface features parameters are researched by the trend analysis method, wavelet analysis, correlation analysis, and gray correlation analysis method. It have the important meaning for more deeply understanding the impact factor of climate change, increasing the accuracy of land surface model and regional climate model, and improve long-term climate prediction. The main conclusions are as following:(1) In the recent50years, the climate performs the tend of drought-warm in the study area, with the trends of decreasing of precipitation, relative humidity, sunshine duration, wind velocity, and the increasing of air temperature, atmospheric pressure. The precipitation has the trend of decreasing in the western, northern, and the most of the central areas, but increasing in southeast part. The air temperature has linear growth trend in the level of0.01significance test for the68%of the meteorological site in the study area. There are obvious periodic oscillations of25～26a,5a for precipitation, and21a,4a for air temperature.(2) In the nearest10years, the distribution trend of NDVI interannual variability is low in the north, high in the south, on rising overall. LAI is on growing in most parts of the study area. The surface temperature is on rising overall, but is on dropping in some of the south areas. The ALBEDO presents reducing trend in northern and eastern, but rising in the southwest.(3) In the spatial scale, the average for precipitation, air temperature and land surface parameters in2001～2010are analyzed for each meteorological station in the study area. The scatter diagram show that there are positive correlations between the climate factors and NDVI, LAI, LST, soil moisture, but there is a negative correlation between the climate factors and ALBEDO, altitude. And the correlation for NDVI, LAI, soil moisture, and ALBEDO to precipitation is higher than the temperature, the relativity for LST, altitude to temperature is greater than rainfall.(4) In the time scale, the correlation between land surface parameters and precipitation, air temperature was analyzed by their annual average. The correlation of precipitation with NDVI, LAI, and soil moisture is positive, with ALBEDO is negative, and is faintish with LST; all of them have not reached the significant level. The relatiohship between temperature with LST is positive, is faintish with NDVI, LAI, ALBEDO, is negative with soil moisture, but all of them have not reached the significant level. There is a certain difference in the spatial distribution. The correlation of precipitation with vegetation indexes is positive in most of the region, is negative with LST and ALBEDO in most of the region. The relativity between air temperature to vegetation indexes and ALBEDO is positive in most of the region, is positive with LST. The sequence of grey correlation degree of precipitation with land surface parameters in the annual scale is as follows:ALBEDO> Soil moisture>NDVI> LAI> LST. The sequence grey correlation degree for air temperature is as follows:LST> Soil moisture> ALBEDO> NDVI> LAI. |
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