【作者】 吴楠；

【导师】 何方；

【作者基本信息】 安徽农业大学 ， 土壤学， 2007， 硕士

【摘要】 一直以来,淮河流域的水土流失都是淮河治理所面对的主要问题,近20年来,流域水土保持工作已经取得了显著成就,然而,淮河流域的水土流失问题并没有得到根本的改善,水土保持任务仍然艰巨。淮河上游山丘区主要包括淮干上游的大别山、桐柏山区,具有巨大的涵养水土、调节河川径流功能,是维护整个淮河流域生态平衡的屏障。然而近年来,区内土地利用方式和结构的不合理诱发了严重的人为水土流失,淮河上游山丘区已经成为淮河流域水土流失最为严重的地区之一。因此,对该区的土壤侵蚀变化进行研究,探索区域土地利用方式的时空演变对区域土壤侵蚀强度的影响,对淮河上游山丘区探询更为有效的水土保持方略和决策具有重要的意义。本研究借助于“3S”技术(RS、GPS、GIS),对采集到的淮河上游山丘区1995年和2000年两期的土地利用方式和土壤侵蚀强度数据,进行动态定量的时空变化分析研究,在此基础上,着重分析了区域5年间土壤侵蚀强度的动态转化和土壤侵蚀强度的区域变化特点以及各种土地利用方式变化对土壤侵蚀强度变化的影响。结果表明:1995年至2000年,淮河上游山丘区的土壤侵蚀强度和面积有较大幅度的减轻。5年间,有较大面积的轻度、中度水蚀转化为微度水蚀,转化面积分别为937.61 km~2和291.46km~2。2000年本区域轻度以上的水力侵蚀面积达6208 km~2,占区域总面积的23.44%,水土流失现象仍较为严重。5年间研究区域金寨县与霍山县的侵蚀综合指数有较大幅度的下降,下降指数幅度都达到了0.28,淮河流域水土保持重点县工程效果显著。1995年至2000年淮河上游山丘区土地利用方式变化主要趋势是耕地大量减少,林地和建设用地迅速增加。5年间,耕地减少1061.34km~2,林地增加837.87km~2,建设用地增加274.62km~2。2000年不同土地利用方式下土壤侵蚀率,在林地利用方式中,灌木林地和疏林地的侵蚀程度最为严重,其侵蚀率高达36.64%和32.37%。在草地中,中覆盖度草地的土壤侵蚀最为严重,其侵蚀率达到70.02%。在耕地中,丘陵区旱地和丘陵区水田土壤侵蚀率最高,分别高达71.95%和48.07%。不合理的开发利用土地资源和经营管理制度会给水土保持带来严重后果。1995年至2000年淮河上游山丘区土地利用方式变化与土壤侵蚀强度变化的关系。土壤侵蚀变化主要发生在水田、旱地、林地、草地这四种土地利用方式中。其中较为明显的是林地中土壤侵蚀强度的下降。轻度、中度和强度类型变成微度类型的面积分别为325.31km~2、156.89 km~2、25.15 km~2。中度类型变成轻度土壤侵蚀类型的面积为90.67 km~2。不同土地利用方式之间的转化对土壤侵蚀变化的影响主要体现在耕地变为林地和建设用地对土壤侵蚀的抑制上。其中土壤侵蚀强度类型由轻度水蚀变成微度水蚀的土地利用方式当中,有21.96km~2为耕地转变为林地斑块,3.14 km~2为耕地转变为建设用地斑块。这表明退耕还林确实是一项行之有效的水土保持措施,此种土地利用方式转化有利于土壤侵蚀强度下降。更多还原

【Abstract】 The soil erosion of Huaihe basin has been the Main issue which the Huaihe basin harnessing has to face up to since 1980.From the latest 20 years,the conservation of water and soil in Huaihe basin has obtained the remarkable achievements,however,the issue of water and soil loss in Huaihe basin was not improved fundamentally.The soil and water conservation is a very difficult task all the same.The mountainous region in upstream of Huaihe river comprise the Dabie mountain area and Tongbai mountain area in the upstream of the mainstream of the Huai River.It has functions that can conserve water resources and regulate river runoff.This region is the barrier that can maintain ecological balance in the whole area of Huaihe basin.But in recent years,the incongruous use of the land induces the serious man-made water and soil loss.The issue of water and soil loss in the mountainous region in upstream of Huaihe river has been the most serious in Huaihe basin.Therefore,the study on the change of soil erosion in this region, exploration to the influence that the change of land use has exert the intension of soil erosion, have significance to search after more efficient methods of water and soil conservation in the mountainous region in upstream of Huaihe river.This research studied on the dynamic change of space and time quantificationally in the mountainous region in upstream of Huaihe river based on the land use and soil erosion data in the year of 1995 and 2000 in virtue of "3S" technology.On this basis,focuses on the analysis of the dynamic change of soil erosion among 5 years and the character of change of soil erosion in cities and counties and the influence that the change of land use has exert the intension of soil erosion.The results indicated that:The intensity and the area of soil erosion in the mountainous region in upstream of Huaihe river have had an impressive alleviation from the year of 1995 to 2000.Among this 5 years,it had biggish area changing from low-grade and moderate water soil erosion to mired water soil erosion.The changing areas were 937.61 km~2 and 291.46 km~2.In 2000,the area of above the low-grade water soil erosion in this region was 6208 km~2,it made up 23.44%of the whole region.The phenomena of water and soil loss was very serious all the same in the region.Among this 5 years,the soil erosion composite index number in the county of Jinzhai and Huoshan had an impressive decline in the studying region.It represented a decline of 0.28.The water and soil conservation engineering of important county in Huaihe basin has achieved remarkable results.From the year of 1995 to 2000,the tendency of the change of land use was the area of arable land fell off rapidly,however,the area of forest land and land used for building increased rapidly.Among this 5 years,the net decrease of the arable land was 1061.34km~2,but the net increase of the forest land and land used for building was 837.87km~2 and 274.62km~2.In 2000,with regard to soil erosion in different kinds of land use,in forest land,the erodibility of shrub land and open forest land was most serious.The erosion rate was 36.64% and 32.37%.In grassplot,the erodibility of the moderate degree of coverage grassplot was most serious.The erosion rate was up to 70.02%.In Arable Land,the erodibility of dry land and paddy field in low-relief terrain was most serious.The erosion rate was 71.95%and 48.07%. The inconsequence exploitation to the land resource and management operating system may bring about the serious result to water and soil conservation.This research discussed the relations between the change of land use and soil erosion in the mountainous region of upstream of the Huaihe fiver from the year of 1995 to 2000.The regions where the intensity of soil erosion have changed in mainly occurs in these four types of land use,such as the paddy field,the dry land,the forest land,the grassplot.Among these four kinds of land use,the intensity of soil erosion had a drop obviously in the type of the forest land. The area of the changing from low-grade,moderate and deep water soil erosion to mired water soil erosion were 325.31km~2、156.89 km~2 and 25.15 km~2.The area of the change from moderate water soil erosion to low-grade water soil erosion was 90.67 km~2.The transformation among different types of land use had influence to the changness of soil erosion.The influence mainly reflected in the reduction of the soil erosion which the transformation that the type of farming land became the type forest land and the construction land lead to.In the kind of land use where the low-grade water soil erosion change to the mired water soil erosion occur in,the area of the change from arable land to forest land was 21.96km~2.The area of the change from arable land to land used for building was 3.14 km~2.This indicated that the returning land for farming to forestry was an effective measure of soil and water conservation.This kind of change to land use was propitious to the alleviation of soil erosion.更多还原