【作者】 李庭波；

【导师】 杨玉盛；

【作者基本信息】 福建农林大学 ， 水土保持与荒漠化防治， 2004， 硕士

【摘要】 随着国民经济建设速度的加快，因开发建设项目而导致的水土流失呈快速增加趋势。但虽然开发建设项目水土流失早已有之，但并未引起人们的足够重视。开发建设项目中的土壤流失量巨大，造成大量泥沙淤积河床水库，降低了水利设施寿命和防洪效率，加剧洪涝灾害，严重危及建设项目和周边人民生命财产的安全，制约着当地经济和社会的可持续发展。与一般的水土流失不同的是，开发建设项目水土流失造成的危害具有多样性、突发性、灾难性的特点；其成因、侵蚀方式、规律等极为复杂，也有别于传统的水土流失规律和过程，导致其治理难度明显高于传统的水土流失。但由于目前我国对开发建设项目水土流失机理和防治研究仍较为缺乏，因而尚难以对开发建设项目水土流失进行科学有效的治理。本文通过对福建省开发建设项目造成的水土流失作用机理、类型、形式、特点、区域分布规律等进行系统研究，为我国开发建设项目水土流失治理提供理论指导，对改善我国的生态环境、实现社会和经济的可持续发展具有重要的现实意义。 本文通过面上调查福建省各地开发建设项目情况及典型调查不同开发建设项目的水土流失强度，探讨了福建省开发建设项目水土流失的区域分布。在面上调查的基础上，选择松散弃土为研究对象进行定位研究，采用坡面径流小区方法定位研究松散堆积土的水土流失规律，探讨松散堆积土水土流失动态及与降雨因子和植被(种草)的关系，并用标桩法探讨不同混合弃土类型对水土流失量的影响。结果表明： (1) 福建省开发建设项目水土流失达17623hm~2，占全省总流失面积的1.18％。开发建设项目水土流失面积以三明市最大。不同开发建设项目水土流失面积中以工矿类(9785hm~2)、城建类(3419.5 hm~2)和交通类(3232.2 hm~2)较大。工矿类水土流失面积所比例以泉州最大(30.88％)；城建类水土流失面积所比例则以福州最大(37.53％)：交通类水土流失面积所比例则以三明最大(27.9％)。 (2) 福建省开发建设项目水土流失强度基本均在强度以上，交通类水土流失强度最大，建设期年平均土壤侵蚀模数高达2.57万t／km~2；其次为工矿类的水土流失强度，年平均土壤侵蚀模数为2.23万t／km~2；城建类水土流失强度为1.93万t／km~2居第三，均属剧烈侵蚀强度。松散弃土在开发建设项目中水土流失强度中最大，可达6万t／km~2以上；其次为挖方边坡，而平整地的水土流失强度较小。 (3) 不同地市中以三明市开发建设项目造成的水土流失最严重，其次为泉州市。全省工矿类、交通类和城建类水土流失量分别达223.3万t、84.4万t和66.5万t，分别占开发建设项目总水土流失量的56.3％、21.3％和16.8％。表明工矿类造成的水土流失是福建省水土保持监督和防治的重点。 (4) 福建省开发建设项目水土流失的共同特点是：①水土流失量大，建设期与运营期有明显的差别。②影响范围大，甚至是跨流域范围的影响。③引起水土流失的物质成分复杂。④水土流失形式多种多样。⑤诱发性水土流失是主要形式。⑥水资源系统破坏严重。 (5) 松散堆积土的年水土流失量为4.414万t／(km~2·a)，属剧烈水土流失强度等级，是原状裸露地流失量1.470万t／(km2·a)的3.0倍；松散堆积土的年径流量(762.9mm)则是原状裸露地(443.Slnm)的1.7倍;松散堆积土年径流系数(0.52)亦显著高于原状裸露地的(0 .30)。松散堆积土种植宽叶雀稗后，第1年水土流失量为1.066万试kmZ·a)，比未种草的松散堆积土减小了75.8%，也低于原状裸露地的;年径流深为339.Slnm，比未种草的松散堆积土降低了55，5%;年径流系数亦下降至0.23，表明种草可显著降低松散堆积土的水土流失量。但松散堆积土种草第1年的土壤流失量仍属极强度流失，而植被保护良好的自然坡地年土壤流失量仅为5.938砍mZ，年径流深仅21.4Inm，可见在开发建设项目中应尽量减少自然植被的破坏。 (6)松散堆积土1年中的水土流失主要发生在3一9月，而7一9月则是水土流失的危险期。松散堆积土种草的水土流失则主要发生在草还未完全覆盖地表前的3个月，该期土壤流失量占其全年的99%以上;而草覆盖地表后，土壤流失则极为轻微。 (7)松散堆积土土壤流失量与降雨量呈显著的幂函数关系，但相关系数均较小。松散堆积土与原状裸露地土壤流失量与降雨强度的相关性高于有植被覆盖的松散堆积土和自然坡地。对各小区l年的土壤流失量贡献最大的是大雨，而以小雨的贡献最小。单场降雨中土壤流失量松散堆积土和原状裸露地以大雨为最大，暴雨次之，其次为中雨，小雨最小;堆积土种草和自然坡地则为暴雨>大雨>中雨>小雨。 (8)各小区可引起水土流失的最小侵蚀性降雨为自然坡地(8 .83mm)>松散堆积土种草(6.90mm)>原状裸露地(6 .75mm)>松散堆积土(4.smm)，有植被覆盖的小区比无植被覆盖的小区最小侵蚀性降雨更高。 (9)不同类型弃土所测得的土壤流失量均有所差异，其大小顺序为细质弃土24332叭kmZ·a)>底土层弃土23551叭km，·a)>砂粒与土壤混合弃土23257叭kjnZ·a)>碎石与土壤混合弃土221 13叭 kmZ·a)。各成份中石粒、砂粒含量大，水土流失量较少。更多还原

【Abstract】 In course of the accelerated economic development, soil and water loss caused by exploitation projects increased meanwhile. Though it has existed for a long time, it has received little attention. The soil loss caused by exploitation projects is so large that it could fill up rivers and reservoirs, lower the longevity and flood control efficiency and aggravate the flood. Compared with normal form of soil and water loss, the losses induced by exploitation projects are characterized by diversity, abruptness and severity. Due to complexity existed in the formation, style and process of soil and water loss in exploitation projects, prevention and control of this erosion is more difficult. Further, recent research on this respect are scarce in China, thus studies on the mechanism and control measurement of erosion caused by exploitation projects are important and urgent, which will favor eco-environment improvement and sustainable development of society and economy.The regional pattern of soil and water loss caused by the exploitation projects in Fujian was studied through an integrate survey on loss area, intensity and types. Based on this, the erosion mechanism of loosely piled soil was studied in the runoff plot scale. In addition, the marked stake method was applied to assess the effects of the makeup of discarded soil on soil loss.The erosion area caused by exploitation projects in Fujian is up to 17623hm2, being 1.18% of the total erosion area, and the Sanming City is the first contributor. The erosion area caused by the mineral, urban and traffic projects is 9785hm2, 3419.5 hm2 and 3232.2 hm2, the first culprit of which is Quanzhou City, Fuzhou City and Sanming City, respectively.The erosion intensity of the soil and water loss caused by exploitation projects is usually higher than the hard-erosion class, and can be ranked as traffic projects (2.57x104t/km2)>mineral projects (2.23x104t/km2)>urban projects (1.93x104t/km2). The loosely-piled discarded soils has the highest erosion intensity (6x104t/km2), followed by the digging-induced side slopes and the level-up lands.Sanming City had the highest amount of soil erosion in Fujian, followed by Quanzhou City. The mineral, traffic and urban projects had an amount of soil erosion of 223.3, 84.4 and 66.5x104t, respectively, being 56.3%, 21.3% and 16.8% of the total soil erosion that caused by the exploitation projects.The common characteristics of soil erosion that caused by exploitation projects are: a) high soil erosion that differed between the construction and carry-outstages; b) large incidence inside and outside of an area; c) complexity in erosion substrate; d) diversity in erosion pattern; e) dominance of induced-erosion; and f) serious destruction of water resources.The annual erosion and runoff of loosely-piled discarded soils was up to 4.414xl04t/(km2 a) and 762.9 mm, being 3.0 times and 1.7 times as high as those of intact bare-land (1.470xl04t/(km2 a) and 443.8 mm), respectively. When loose-piled soil is covered with grass, water and soil loss decreased significantly, with decreased proportions of 75.8% and 55.5% for amount of soil loss and runoff respectively.The soil erosion of loosely-piled soil occurred mainly during March to September, and July to September are the most risk period of erosion. As for the loosely-piled soil with seeding treatment, 99% of the annual erosion occurred during the period before grasses fully-covered the land, that is, 3 months after seeding.Amount and intensity of rainfall are two key factors influencing soil and water loss. Relation between rainfall amount and soil loss are more significant in uncovered land than that in covered land. Compared with the relation between rainfall amount and soil loss, the relation between rainfall intensity and soil loss is more significant. This holds true for the relation between soil loss and uncovered and covered lands respectively. Soil erosion caused by a rain event can be ranked as: downfall > rainstorm > medium rain > sprinkle. The minimum erosive rainfall are in the更多还原