石碗溪小流域土地资源可持续利用评价

【作者】 罗云云；

【导师】 李瑞雪； 屈明；

【作者基本信息】 西南农业大学 ， 土壤学， 2004， 硕士

【摘要】 山区小流域是以分水岭和出口断面为界形成的自然集水单元，是具有一定水文学特征的自然、社会和经济综合体。作为山区经济发展和生态环境建设的有效途径，以小流域为基本单元进行的综合治理已在国内外普遍展开，小流域综合治理效果评价也随之成为研究的热点，但有关小流域土地资源可持续利用评价研究并不多见。小流域是三峡库区基本地貌组成单元，小流域土地资源不合理利用是导致三峡库区水土流失、经济发展缓慢等问题的重要原因。因此，开展小流域土地资源可持续利用评价是非常必要的。本文以重庆市开县石碗溪小流域为例，进行土地资源可持续利用评价，这不仅能为该小流域土地利用规划提供参考依据，而且对加快三峡库区小流域综合治理，推动西部生态环境建设也有重要意义。 本研究的总体思路是：总结、归纳已有研究成果，探讨小流域土地资源可持续利用研究的理论方法；在理论指导下，系统分析石碗溪小流域自然、社会经济状况及其土地资源特征、利用现状等，据此选择小流域土地资源可持续利用评价指标；用主成分分析法综合评价指标，对小流域1996～2002年土地资源可持续利用进行评价，揭示小流域土地利用存在问题及其原因；最后，提出小流域土地资源可持续利用对策。 1 石碗溪小流域土地利用分析 用GIS软件分析，发现小流域土地面积随坡度和海拔增加而增大。按坡度统计，＜15°、15～25°、＞25°土地分别占总面积的18.54％、27.30％和54.16％；按海拔高程统计，＜500m、500～800m、＞800m土地分别占总面积的22.46％、30.15％和47.38％。小流域林地、耕地、园地分别占土地总面积的43.17％、23.39％和13.31％，且呈垂直分异性，林地集中在海拔高程800m以上的斜坡和陡坡，园地成片分布在海拔高程500m以上的缓坡和陡坡。 与有林地相比，小流域典型土地利用方式的土壤均有一定退化。以有林地为基准，考虑容重、有机质、全量氮磷钾，计算土壤退化指数，负值表示退化。疏林地、天然草地、梨园、柑桔园、旱坡地土壤退化指数分别为-10.09％，-18.37％，-5.73％，-6.52％，-8.46％。 分析小流域土地利用的社会经济状况，发现其农业产业结构与土地利用结构不协调。小流域种植业、林业、畜牧业、水利和工副业投入产出分析表明，种植业的社会总产值、净产值和社会纯收入所占比例均最大，说明种植业仍是主要行业，而林果业每百元物质消耗提供的净产值只有96.14元，处于高投入低产出状态，这是由其效益的长期性决定的。 2 石碗溪小流域土地资源可持续利用评价 依据小流域自然、社会经济状况及其土地资源特征和利用现状，参考有关资料，采用频度统计、系统分析、专家咨询等方法，选择小流域土地资源可持续利用评价指标。目标层为土地资源可持续利用；准则层为土地生产力不下降、生产稳定性、土地保护性、经济可行性和社会可接受性；指标层包括单位果园产值、有效灌溉面积比率、水土流失治理面积、单位 西南农业大学硕士学位论文摘要目口皿....口目里皿..口..化肥施用量、农林牧渔产投比、土地管理综合特征指数等24个指标。 借助DPS软件，用主成分分析法对小流域1 996~2002年的土地利用进行评价。主成分分析产生11个综合评价指标，以此对小流域土地利用的土地生产力、生产稳定性、土地保护性、经济可行性和社会可接受性分别进行评价。发现小流域土地利用中，土地保护性呈下降趋势，其他方面则是持续发展的。再以五个准则层为指标，对小流域土地利用进行综合评价，199卜200()2年土地资源可持续利用指数分别为一3.43、一1.96、一0.95、一0.2、1.12、2.22、2.79，表明石碗溪小流域土地资源可持续利用整体水平不断提高。3石碗溪小流域土地资源可持续利用对策 针对小流域土地利用及经济发展中存在问题，结合小流域实际，提出几点对策，以为小流域土地资源可持续利用及经济可持续发展提供参考。一是深化农业产业结构调整，重点在于提高林果、畜禽、蔬菜、牧草等特色产业的比重，即要调整优化粮经结构、品种结构和种植结构，实行产供销一体化经营，采用公司+农户经营模式，规模生产。二是充分利用资源优势，应用景观生态学思想与方法，合理布局农林牧业用地。小流域上部，以水土保持为主，发展林业;小流域中部，既要保持水土又要发展经济，经济林果业、林业和牧草业共同发展;小流域下部，生产条件较好，可开展各种经济生产活动，但要采取一定的措施防止水土流失。三是加强农业投入，尤其是科技投入，加强农业实用技术培训，如农产品精加工及综合利用、农产品贮藏、保鲜、包装等技术，提高土地产出率。同时，还应大力推广沼气池、坡改梯、退耕还林等生态工程，保护土地，改善生态环境。四要搞好农村劳动力的培训和信息服务铸工作，提高劳动者素质，增强竞争力，增加收入。充分利用各种优惠政策，积极鼓励外出务工人员回乡创业，走“轴出一成才一积累一创业一共同富裕”之路。更多还原

【Abstract】 Mountainous small watershed is a natural catchments as well as a complex system out of the sub-system of ecology, economy and society. The comprehensive management using small watershed as unit is an effective approach to ameliorate the economical environment and accelerate agriculture and rural economy development. Evaluation of management effect in small watershed has been the studying hotspot, but study on land resources sustainable use in small watershed is still in primary period. Now, the Three Gorges Reservoir Area is faced with three serious problems, namely, the deterioration of ecological environment, the economic poverty and the resettlement of over one million people and irrational land use in small watershed is one of the main reasons for the serious soil erosion and economic poverty in TGRA. Taking Shiwanxi small watershed as a case, the author made an assessment on the land resources sustainable use and the results of this paper were expected to provide scientific references not only for the local government, but also for the TGRA in small watershed management and construction of ecological environment.The general consideration for this study was to summarize and conclude existing results and establish a theoretical foundation for proving study and policy undergoing. Detected by the theoretical system, a survey was made on land resources, natural, social and economic conditions in Shiwanxi small watershed. Based on this, the author selected some indexes with methods of Systems Analysis and Frequency Stat then assessed the land use from 1996 to 2002 with the Main Component Analysis Method. Finally, the paper provided strategic idea and practical countermeasures for land resources sustainable use and economy sustainable development according to the existing problems revealed by the assessment.1 An analysis of land use in Shiwanxi small watershedAnalyzing the land resources and land use with GIS, the author found the areas of land increased with the steep of slope and the rise of altitude. The slopes and elevation was separately divided into 3 grades according to the impact levels on the land use. Slope grades were: 0-15°, 15-25°, >25° and their proportions was 18.54%, 27.30% and 54.16% respectively. Elevation grades were: <500m a.s.1, 500-800m a.s.1, >800m a.s.1 and their proportions was 22.46%, 30.15% and 7.38% respectively. In the watershed, woodland, infield and garden plot respectively accounted for 43.17%, 23.39%, 13.31% and appeared obvious vertical differentiation, that was, woodland was mainly distributed on the slopes of >25° over 800m a.s.1 and garden plot was mainly distributed on the slope of 0-15° and 15-25° below 800m a.s. 1.How to use rationally the lands in mountainous small watershed is very important to preservesoi 1 quality and develop sustainable land use model. There was a study undertaken to evaluate the effect of land use on soil quantity. Thinking of soil organic matter, total N, total P, total K and soil granule composition, the soil degradation index was calculated and that of woodland, sparse woodland, crude grassland, garden plot of pear, garden plot of mandarin orange and slope dry land was separately -10.09%, -18.37%, -5.73%, -6.52% and -8.46% compared to woodland. The results indicated that deforestation and cultivation led to severe soil degradation.This article also analyzed the social and economic conditions. The input-output analysis showed that the agriculture structure did not correspond with land structure. In the constitution of all products, plantation occupied the most and it was the main income resources. At the same time, the forest and fruit were in low benefit with net income of 94.16yuan per 100yuan because the benefit was long-term.2 Sustainable assessment of land use in Shiwanxi small watershedBased on the land resources, land use, natural, social and economic conditions of Shiwanxi small watershed and the existing study results, 24 indicators were put forward with methods of Systems Analysis and Frequency Stat to更多还原