文档介绍：青海省南部高寒区土地退化格局与程度评价摘要: 土地退化是青藏高原严重的渐发性自然灾害之一。青海省南部高寒区地处青藏高原腹地,是江河源头区、气候变化敏感区、生态环境脆弱区和少数民族聚居区,是中国可持续发展的生态屏障。在分析该区土地退化态势的基础上, 利用区位指数法探讨了土地退化的基本格局。目前该区形成了以沙化型退化、黑土滩型退化和鼠害型退化为主导, 其他类型( 冻融侵蚀型退化、毒杂草型退化、虫害型退化、盐碱型退化及水力侵蚀、风力侵蚀等) 发育不等的土壤退化体系, 具有退化类型的多样性、分布的广泛性、程度的严重性、发展的快速性、危害的长期性、影响的深远性。利用综合评价指数法对土地退化程度进行了评价, 并根据评价结果划分了极重度退化区(玛多、达日县) 、重度退化区(曲麻莱、称多、玉树、同德、泽库、班玛县) 、中度退化区(治多、杂多、囊谦、兴海、玛沁、甘德、久治、河南县)和轻度退化区(格尔木市唐古拉山乡) 4个土地退化等级区域。关键词:高寒区;土地退化;格局;程度;评价;青海省 abstract: land degradation wa s one of the serious gradual oc curring natural disasters on q inghai-tibet plateau. the sout hern part of qinghai province l ocating in the hinterland of qi nghai-tibet plateau was the ri ver source region sensitive to climate change sensitive with fragile ecological environmen t area which was inhabited by e thnic minorities , and was ecolo gical barrier for sustainable development of china. the land degradation trend in this regi on was discussed using locatio n index method based on analysi s of land degradation pattern. at present , the main deteriorat ed patterns of this area were d esertified deteriorated , black beach degradation and rodent d egradation together with some other types (freeze-thaw erosi on degradation, poisonous weed s degradation, pest deteriorat ed, salinity-type degradation and water erosion, wind erosio n, etc .). the degradation system was with characters of various degraded type, wide distributi on , serious degree , rapid devel opment , sever hazard and far-re aching impact. prehensi ve index evaluation method was adopted to evaluate the degree of land degradation. according to the evaluation results, the land was divided into 4 degrada tion grades including extremel y severe degradation zone ( madu o, dari county ), severe degrada tion zone ( quma c ai , chenduo , yus hu , tongde , zeku , banma county ), moderate degraded zone ( zhiduo , zaduo, nangqian, xinghai, maqi n, gande , jiouzhi , henan county ) and mild degraded zone ( tanggu lashan township ). key words: high co