张家口市崇礼区景观生态风险评价

Assessment of landscape ecological risk in Chongli district of Zhangjiakou city

为探明河北省张家口市崇礼区土地利用变化对区域景观生态风险的影响,本文利用1990、2000、2010、2015年崇礼区Landsat遥感影像,将研究区分为林地、草地、耕地、建设用地、未利用地和水域6种景观类型,计算其景观生态风险评价相关指数,结合空间插值法,将研究区分为低、较低、中等、较高和高生态风险区,解析该区域景观格局和景观生态风险时空变化特征。结果表明:1990—2015年期间,崇礼区景观格局变化明显,林地和水域景观面积百分比分别减少17.81%和0.13%,草地、耕地、建设用地和未利用地景观面积分别增加11.01%、4.56%、1.88%和0.49%。人为对景观斑块的破碎化干扰较大,研究区景观损失度指数大小排序为:水域>未利用地>耕地>草地>建设用地>林地。低生态风险区面积减少12.89%,较低、中等、较高和高生态风险区的面积分别增加0.71%、0.60%、2.88%和8.70%,研究区以中等和较高生态风险等级为主,整体生态风险呈增加趋势,高等级生态风险有向崇礼区中部和北部扩张的趋势。

The study aims to reveal the impact of land use change on regional ecological risk in Chongli district of Zhangjiakou city,Hebei province.Landsat images of 1990,2000,2010 and 2015 were obtained.In the study area,landscape was classified into six types,including woodland,grassland,cultivated land,construction land,unutilized land and water.Ecological risk index and landscape indices were calculated and spatially interpolated for assessing the spatio-temporal changes in ecological risk for each landscape pattern.The results showed that the regional landscape patterns had experienced significant changes,and the decrease in the area of woodland and water were 17.81%and 0.13%from 1990—2015,and the increase in the area of grassland,cultivated land,construction land and unutilized land were 11.01%,4.56%,1.88%and 0.49%,respectively.The fragmentation of landscape patches were influenced by human.The order of landscape index in the study area was:water>unused>farmland>grassland>construction land>forest land.During the study period,the overall patch number of the landscape increased,and fragmentation of the landscape increased accordingly.The ecological risk of the study area was dominated by medium and higher risk,and during the study period,the area for the low risk reduced by 12.89%,while the area for lower,medium,higher and highest risk increased by 0.71%,0.60%,2.88%and 8.70%,respectively.The overall ecological risk tended to increase,and the high-level ecological risk tended to expand to the middle and north area of Chongli district.