A Research On NPP Of Land After Reclamation By CASA Model In Pingshuo Mine

This paper uses CASA model, combined with Landsat TM images and related climate data, the use of ENVI, ArcGIS and MapGIS software, to carry out the net primary production (NPP) of vegetation in large-scale open-pit Pingshuo mine. This study estimated mining vegetation NPP of four-year period in 1987, 1996, 2001 and 2005, the conclusion of the study are as follows:1. Based on 1987-2005 changes in the NPP and the process parameters such as the NDVI, the study analyzed the vegetation changes and reclamation in the mine area over the past 20 years. Overall, there was a downward trend in the NPP of vegetation from 6.47g C·m-2month-1 in 1987 to 6.06g C·m-2month-1 in 2005, but the NPP gradually stabilized. The NPP of the main Antaibao mine area reduced with the exploitation, from 5.57g C·m-2month-1 in1987 to 1.02g C·m-2month-1 in 2005. The NPP of Anjialing mine reduced in 2001, but improved to 4.82g C·m-2month-1 in 2005. The NPP of dump after reclamation increased over the years after 1996 and beyonded the NPP of the all categories to the maximum. The NPP was 11.03 g C·m-2month-1.2. This paper counted the NPP of different types of land-use in accordance with the results of the four-year period images interpretation in the mining area. The study analysed the patial and temporal distribution of NPP and found that the value of natural forests and plantation were the highest, the value of shrub land was the lowest and the changes of the NPP of arable land was relatively small, the stability was the highest. The result explained that forest would be the main direction of reclamation at the same time part of land could be changed into arable land. In this way the NPP can beincreased, but also to strengthen the stability.3. This study analyzed the relationship between the changes of the years'NPP in Pingshuo mining area and climate, reclamation measures, mining strength. Rainfall was the greatest impact on the NPP. The NPP of vegetation in the mining area changed with the exploitation of coal resources. When the exploitation strengthened the NPP would reduced. Reclamation measures were the effective ways to increase the NPP in mining area. In the same period the vegetation productivity of the land after reclamation had been significantly better than the vegetation of original topography.4. This study simulated the future distribution and change of NPP in sub-period and sub-scenarios. By comparing the paper found that the ecosystems after reclamation and rehabilitation would be the most stable model in the three simulated systems under the principle of maintaining the balance of the total amount of arable land. The NPP of the ecosystems would be the highest and finally beyonded the carrying capacity of the original ecosystem after a certain period.5. CASA model has a certain degree of applicability in small-scale. This paper, based on the CASA model, the use of medium-resolution TM data and in accordance with the actual situation of the mining area and the data collection simplified the model so that the model can serve for the mine land reclamation. The research results showed that the NPP of vegetation could basically reflect the actual situation of the mining area. The results had a certain degree of practicality.