Study On The Grassland Degradation And Water Conservation In The Three-River Headwaters Region

With the increasing influence of human activities on the ecological environment,the contradiction between human and ecological environment are increasingly prominent.As the mearn cover of the Three-River Headwaters region,the phenomenon of human activity is more serious to the grassland.The Three-River Headwaters region is the main source of water conservation service in china.So water conservation function is obviously affected by the change of cover.As an ecological environment itself with all kinds of ecological service function appear a different degree of change affected by human activities directly or indirectly.To fully understand and know the impact of these changes for the present and the future development become a problem we need to be addressed.In this paper,Means of Remote Sensing inversion was used to calculate the grass coverage in the Three-River Headwaters region.Based on compared the grass coverage in different times with grass coverage of the reference system,grassland degradation results in the different periods was got in the Three-River Headwaters region.Grassland degradation was classification according to the national standard(GB19377-2007).Grassland degradation can be divided into four level,such as heavy,medium,light and no degradation.Through calculation,the following results are obtained.Grassland degradation rate is 86.23%in 2000,79.77%in 2005 and 56.38%in 2010.In the last ten years,grassland degradation of the Three-River Headwaters region shows the tendency of improvement.At the same time,the InVEST model was used to estimate the amount of water conservation in the Three-River Headwaters region.In the end,water conservation in 2000,2005 and 2010 was got.The value of the water conservation was 216.39 mm,226.84 mm and 260.17 mm.The results show that the water conservation in the Three-River Headwaters region showed a trend of growing in the recent ten years.SPSS was used to analyze the correlation analysis between the degradation degree and water conservation in different time period and different degradation levels.The probability P?0.05,and the negative correlation coefficient R =-0.86.A negative correlation was proved between them.Water conservation capacity will diminish since the Grassland degradation become serious.Under the condition of different years and different degradation ratio,the correlation can also be got.