科尔沁沙地沙漠化风险评价

基于气象、土地利用类型与植被覆盖指数等数据，采用层次分析法与加权综合评分法评价了科尔沁沙地沙漠化风险。结果表明：1995、2000、2010年科尔沁沙地沙漠化风险指数平均值分别为0.420、0.428、0.437，16年来科尔沁沙地沙漠化处于高度风险水平。科尔沁沙地沙漠化风险等级在空间分布上表现为北部与西部沙漠化风险等级低，南部与东部为沙漠化高风险区。1995-2010年科尔沁沙地各旗县沙漠化风险等级存在差异，开鲁县的沙漠化风险由高度风险转变为极高度风险等级，扎鲁特旗的沙漠化风险由中度风险转变为低度风险等级，敖汉旗、巴林右旗、科尔沁区与科尔沁左翼中旗的沙漠化风险等级波动变化，其余旗县的沙漠化风险等级未变化。1995-2010年科尔沁沙地沙漠化中度，高度风险等级的面积分别减少了16 544.76、4 223.25 km²，低度，极高度风险等级的面积分别增加了16 544.76、4 223.25 km²。区域沙漠化风险的主要影响因素为年降水量、年均风速、植被覆盖指数、沙漠化土地面积与载畜量，植被覆盖指数增加有助于区域沙漠化风险的降低。

Desertification Risk Assessment in Horqin Sandy Land

By using analytic hierarchy process and synthetic grade weighting process based on climate data, land use data and vegetation coverage index desertification risk in Horqin sandy land was assessment. Results showed that the average desertification risk index were 0.420, 0.428, 0.437 in the year of 1995, 2000, 2010, respectively. Desertification risk of Horqin sandy land was high grade in 1995 to 2010, and counties of low desertification risk grades distributed in the north and west, while high desertification risk grades distributed in the south and east. Desertification risk grades of different counties showed a discrepancy from 1995-2010. Desertification risk grade of Kailu County increased, while desertification risk grade of Zhalute Banner decreased, Aohan Banner, Balinyou Banner, Horqin District and Kezuozhong County showed a fluctuant change, the other counties had not change. Area of medium desertification risk grade and high desertification risk grade decreased by 16 544.76 km² and 4 223.25 km² from 1995 to 2010, while area of low desertification risk grade and extreme high desertification risk grade increased by 16 544.76 km², 4 223.25 km², respectively. The main factors that affect regional desertification risk were annual mean precipitation, annual mean wind speed, vegetation coverage index, area of sandy land and grazing capacity, and increase vegetation coverage index contribute to the decrease of desertification risk.