摘要
以青藏高原、黄土高原和秦巴山区三大地形交汇过渡带水土流失的典型流域——甘肃白龙江流域为研究区,结合RUSLE模型和生态风险评价方法,定量分析流域尺度的水土流失景观生态风险时空分异特征。结果表明:(1)白龙江流域水土流失景观生态风险较高,中等风险区以上面积占研究区总面积的48%;在空间上,白龙江两岸及其以北区域、岷江沿岸和迭部县西北部地区的景观生态风险高于其他地区。(2)景观生态风险格局变化不大,呈先增加后减弱的趋势,尤其在2002年后,低风险区迅速增加,其面积达280.89 km2,表明研究区水土流失治理效果显著。(3)水土流失的景观生态风险主要集中在未利用地和耕地(尤其是坡耕地),而林地的生态风险最低;武都区水土流失景观生态风险面积最大。今后重点治理的区域应集中在马街乡、洛塘镇、安化镇、汉王镇、鱼龙乡、浦田乡、熊池乡、桔柑乡和两水镇北部等区域。
Bailongjiang watershed, a typical soil erosion area located in the ecotone among the Loess Plateau, Tibet Plateau and Qinba Mountains, was selected as a case to study the landscape ecological risk of soil and water erosion at the watershed scale. We integrated the revised univer- sal soil loss equation （RUSLE） and landscape ecological risk index （LER1） by raster layers in a GIS workstation to identify and assess the spatio-temporal characteristics of landscape ecological risk （LER）. The factors used in RUSLE and LERI were obtained by using different data from meteorological stations, soil surveys and maps, digitized topographic maps, NDVI, DEM and Landsat TM images. And then, the LER of water and soil erosion was classified into five levels ： low, slight, moderate, intense and severe, and dynamically monitored from 1990 to 2010 with the spatial analyst tool of ArcGIS 9.3. The results showed that ： （ 1 ） the value of LER was high and the proportion of above the moderate erosion risk level was up to 48%. As to the spatial dis- tribution pattern, the high risk area mostly located along the Bailongjiang and its tributaries, Minjiang River, northern and northwestern parts of Diebu County. （2） The change of I,ER pat- lern was small and tended to be weakened during the period of 1990-2010; especially after 2002, the low erosion risk area increased obviously with an increase of 280.89 km2, showing that the performed water and soil conservation measures were very effective. （3） The higher risk of the soil and water erosion mainly occurred on the slope cuhivated land and unused land, while the lower risk type was the forestland. At the same time, the ecological risk of water and soil ero- sion in Wudu district was the highest （55.38%）. Consequently, more attention shouhl he paid on these towns, such as Majie, Luotang, Anhua, Hanwang, Yulong, Putian, Xiongchi, Jiegan, and northern Liangshui of Wudu District, to control the soil and water loss in the future. Ourstudy showed that the RUSLE-GIS model was a useful tool for evaluating and mapping LER of wa- ter and soil erosion quantitatively.
出处
《生态学杂志》
CAS
CSCD
北大核心
2014年第3期702-708,共7页
Chinese Journal of Ecology
基金
国家自然科学基金项目(41271199)
国家科技支撑计划项目(2011BAK12B06)资助
关键词
水土流失
RUSLE
景观损失指数
生态风险
白龙江流域
soil and water erosion
revised universal soil loss equation （RUSLE）
landscapevulnerability
ecological risk
Bailongjiang watershed.
