松嫩平原水土保持价值复合计算模型的建立及应用

松嫩平原的生态环境在近几十年间严重恶化，荒漠化迅速发展，这与该区域水土保持功能持续下降有关。根据生态学、经济学和生态环境科学等学科的有关理论，以TM/MODIS/DEM数据为基础，应用3S技术建立了水土保持价值的复合计算模型，并以松嫩平原为研究区进行应用。计算结果表明，全区2001年水土保持价值总额为662.63亿元。就单位面积的水土保持价值而言，林地最高，为173.59 万元/km²；草地次之，为70.42 万元/km²；耕地较低，为24.53 万元/km²;难利用地仅为2.89 万元/km²。水土保持价值的分布趋势从东北向西南递减，从193.86 万元/km²降至18.87 万元/km²。可见，进行林地、草地建设是提高区域水土保持功能的关键，平原中、西部尤应加强水土保持工作。不仅解决了水土保持价值的量化问题，而且，为绿色GDP的核算提供了基础数据。

A Quantitative Computation Model of Water and Soil Conservation Value in Songnen Plain

In recent decades, the ecological environment of Songnen Plain had deteriorated severely and the desertification in Songnen Plain expanded rapidly, which is related to the durative descending of territorial function of water and soil conservation.　Applying the theories of bionomics, economics, environmental science and the technology of 3S, a multiple computation model for water and soil conservation value in Songnen Plain is put forward based on DEM and TM/MODIS data. The calculation results indicate that the water and soil conservation value was 6.626 3×10¹⁰Yuan RMB in 2001 in Songnen Plain. The water and soil conservation value per unit area in forest was the highest with the value of 1.735 9×10⁶ Yuan per km² and the grassland and the cropland was 7.04×10⁵ Yuan per km2, 2.453×10⁵ Yuan per km² repectively. The land that was difficult to use had a value of 2.89×10⁴ Yuan per km². The water soil conservation value tended to be digressive from northeast to southwest in spatial distribution. The water and soil conservation value was descending from 1.938 6×10⁶ Yuan to 1.887×10⁵ Yuan per km². These results indicated that the key to heighten the function of territorial water and soil conservation is to enhance the eco construction for forest and grassland, and it should strengthen the water and soil conservation work especially in middle and western area of Songnen Plain. The trial to quantitatively evaluate the water and soil conservation will supply a basic data for green GDP accounting.