重庆市土地利用变化及其碳排放效应研究

发布时间：2018-04-24 23:41

本文选题：土地利用 + 碳排放　；参考：《重庆师范大学》2017年硕士论文

【摘要】：由全球气候变化带来的冰川消融、极端天气、物种灭绝、海平面上升以及各种自然灾害的频发,已经使社会发展中的粮食安全、能源安全和生态环境安全等面临严峻的直接威胁。大量的研究表明,引起全球气候变化的人类活动影响主要有两方面的表现:一是因煤炭、石油和天然气等化石燃料为主的传统能源消耗引起的碳排放现象;二是因土地利用类型变化引起的温室气体大量排放现象。根据世界自然基金会报告,大约将近10亿吨的碳排放是因土地利用类型变化而被忽视;土地利用类型变化对全球大气中CO2含量的增加有着举足轻重的影响。所以在低碳经济的大环境背景下,如何实现低碳排放的土地利用规划和管理就显得格外重要。本文以重庆市五大功能区为研究对象,结合RS和GIS、Markov和Logistic模型以及CA-Markov模型,在1995年、2005年和2015年三期土地利用数据的基础上,分析重庆市五大功能区1995-2015年土地利用类型间的变化及其影响因子;构建CA-Markov模型,然后对重庆市各大功能区未来土地利用变化类型进行模拟;再运用碳排放模型对重庆市1995-2015年以及未来各土地利用类型的碳排放量和总碳排放量进行初步核算。以期为西南山区三峡库区典型的经济和生态环境保护区的可持续发展提供参考,对科学有效的制定土地规划及管理工作具有指导作用和现实意义。主要内容如下:(1)从土地利用的数量变化和土地利用空间分布变化两方面对重庆市各大功能区1995-2015年土地利用动态进行分析:各大功能区均是耕地和未利用地持续减少,而林地、草地、水域和建设用地呈现不断增加的趋势。在数量上,20年间各个分区的耕地均不断减少,其中都市功能核心区及拓展区耕地减少最多,减少面积比例高达16.20%;林地持续增加,其中城市发展新区增幅最大,增长的面积比例最高达11.58%;草地、水域和建设用地在各功能区均持续增长,且涨幅相近;未利用地基数较小,虽然也持续减少,但总体影响不大。渝东北生态涵养发展区和渝东南生态保护区的各土地利用类型变化基本保持稳定,且与整体变化较一致。在空间分布上,全区域主要是林地、耕地、草地和建设用地这四类分布范围最广;各个功能区整体的用地类型空间分布变化剧烈程度均是建设用地未利用地耕地水域草地林地。(2)土地利用变化的影响因子分析。本文选取的影响土地利用类型变化的因子主要有自然环境、空间距离和社会经济三方面。耕地变化最显著的解释变量是社会经济因素,空间距离因素起到了持续稳定的重要作用;社会经济因素对林地类型发生变化的作用持续显著;社会经济因素(常住人口密度、农民纯收入)和空间距离(到原有草地距离)对草地类型变化的发生起到较大作用;对水域变化影响最大的是空间距离中到原有水域的距离;社会经济因素对建设用地的影响显著,并且重要性明显上升;社会经济因子中的常住人口密度和薪材需求量以及空间距离因子中的到道路距离和到居民点距离,对未利用地变化的发生起到较大影响。(3)土地利用预测及精度检验。运用markov模型得到土地利用面积转移矩阵,结合土地利用变化影响因子,制定合适的转换规则,再运用logistic回归模型生成土地利用适宜性图集,然后利用ca-markov模型模拟重庆市2015年土地利用格局,与2015年实际土地利用数据对比,分析并验证该模型预测的精确性,检验的kappa系数达到0.87,大于0.75,符合模拟精度要求。因此可对未来10年即2025年的土地利用变化进行预测模拟,并根据对转换参数的修改得到不同情境下的土地利用模拟预测数据。(4)重庆市未来土地利用分情景模拟。在三种不同的情景下,土地利用类型在数量变化上,每一种用地类型的总量趋于逐渐稳定的态势,变化的速度和幅度也均有不同程度的下降;在空间格局上,变化最为剧烈的是建设用地的发展,基本上集中在原有建设用地的边缘以及交通道路的边沿,因此原有建设用地边缘以及交通道路边沿的耕地、林地、草地或水域等其他用地类型均会出现不同程度的被侵占,这是城市发展的必然结果。(5)重庆市土地利用碳排放效应分析。从1995年到2015年的20年间,重庆市总碳排放量处于持续增长的状态,增加了3826.65?104t,增长率达78.80%。耕地中的农作物是既有碳排放的作用,同时又会产生一定的碳吸收;林地作为所有用地类型中主要的碳汇,其碳吸收能力是所有用地类型中最强的;草地、水域和未利用地本身表现为碳汇作用;建设用地是主要的碳源,其碳排放强度远远大于其他用地类型能够吸收的强度,导致整个重庆市均表现为碳排放的状态。(6)对未来各土地利用类型碳排放进行预测。情景1中六大地类的碳排放类型中,耕地、水域和建设用地仍是碳源,建设用地的碳排放量较10年前增长迅速,且增长率高达35.80%;林地、草地和未利用地这三类全为碳汇。情景2中整体用地类型的碳汇碳源表现功能不变,不同的是建设用地碳排放量增长达到了前所未有的峰值,而其他用地类型无论是碳排放作用还是碳吸收作用,都远远无法企及建设用地对重庆市碳排放的整体影响,直接导致2025年重庆市的碳排放量呈现出暴增状态。情境3下的碳源和碳汇在相关措施的实施下有增有减,但明显可以看到:在整个区域碳排放量几乎起绝对性作用的建设用地的碳源作用在明显减弱;耕地和水域的碳排放量也持续较小,但对整体影响有限;而林地、草地和未利用地三类起主要碳汇作用的用地类型,在相关政策的颁布和实施下,碳吸收强度明显的增强。由于起压倒性作用的建设用地碳排放强度的大幅度减弱,使得情景3情况下的总碳排放量增长比例最小,仅有18.65%。
[Abstract]:The melting of glaciers from global climate change, extreme weather, extinction of species, rising sea level and the frequent occurrence of various natural disasters have made the social development of food security, energy security and ecological environment facing severe direct threats. A large number of studies have shown that human activities that cause global climate change are mainly affected. Two aspects of the performance: one is the carbon emissions caused by the traditional energy consumption of fossil fuels such as coal, oil and natural gas, and the two is a large amount of greenhouse gas emissions caused by the change of land use types. According to the world natural foundation, about 10 billion tons of carbon emissions are ignored by the change of land use types. The change of land use type has an important influence on the increase of CO2 content in the global atmosphere. Therefore, under the background of low carbon economy, how to realize the land use planning and management of low carbon emissions is particularly important. This paper takes the five major functional areas of Chongqing as the research object, combining with the RS and GIS, Markov and Logistic models. And CA-Markov model, based on three periods of land use data in 1995, 2005 and 2015, the change of land use types between the five functional areas of Chongqing and its influencing factors are analyzed, and the CA-Markov model is constructed, and then the types of land use change in the major functional areas of Chongqing are simulated, and carbon emission models are used again. In order to provide reference for the sustainable development of the typical economic and ecological environmental protection areas in the Three Gorges Reservoir area of the southwest mountain area, the type of carbon emission and total carbon emissions of various land use types in the 1995-2015 years and the future of Chongqing city are preliminarily calculated. The main contents are as follows: (1) from two aspects of the change of land use and the spatial distribution of land use, the land use dynamics of each major functional area in Chongqing are analyzed in the following two aspects: all the major functional areas are the continuous reduction of cultivated land and unused land, while the forest, grassland, water and construction land are increasing trend. In the past 20 years, the cultivated land in each area has been reduced continuously, of which the urban functional core area and the extended area arable land decreased most, the proportion of the area reduced to 16.20%, the forest land continued to increase, and the urban development area was the largest increase, the growth area ratio was up to 11.58%; the grassland, water and construction land were increasing continuously in all functional areas, and the increase phase The unused ground base number is smaller, although it has been reduced, but the overall impact is not significant. The land use types of the Ecological Conservation Development Zone in Northeast Chongqing and the Southeast Chongqing ecological protection area are basically stable and consistent with the overall changes. In the spatial distribution, the whole region is mainly the four types of distribution models of woodland, cultivated land, grassland and construction land. The extent of the spatial distribution of land use types in each functional area is the most important. (2) analysis of the influence factors of land use change. The factors influencing the change of land use types mainly include natural environment, space distance and social economy three aspects. The most significant explanatory variable is socioeconomic factors, space distance factors play an important role in sustainable stability; social and economic factors have a significant effect on the change of woodland types; social and economic factors (resident population density, farmers' net income) and space distance (to the distance from the original grassland) are more important to the change of grassland types. The greatest impact on water change is the distance from the space distance to the original water area; the social and economic factors have a significant impact on the construction land, and the importance is obviously increased; the density of the resident population and the demand for the pay timber in the social and economic factors and the distance from the road to the residential point in the space distance factor and the distance to the residential area are not used. The occurrence of land change has a great influence. (3) land use prediction and accuracy test. Using the Markov model to get the land use area transfer matrix, combining the influence factors of land use change, formulating appropriate transformation rules, then using logistic regression model to generate the suitability map of land use, and then using the CA-Markov model to simulate Chongqing city. The land use pattern in 2015, compared with the actual land use data in 2015, analyzed and verified the accuracy of the model prediction. The kappa coefficient of the test was 0.87, more than 0.75, which was in line with the requirements of the simulation precision. Therefore, the land use changes in the next 10 years or 2025 could be predicted and simulated, and different conditions were obtained according to the modification of the transformation parameters. The land use simulation forecast data under the border. (4) Chongqing city future land use classification simulation. Under three different scenarios, the land use type in quantity change, the total amount of land use type tends to be gradually stable, the speed and amplitude of change also have the same degree decline; in the spatial pattern, the most dramatic change It is the development of the construction land, which is mainly concentrated on the edge of the original construction land and the edge of the traffic road. So the original construction land edge and the cultivated land, woodland, grassland or water area will be occupied in different degrees, which is the inevitable result of the development of the city. (5) Chongqing City In the 20 years from 1995 to 2015, the total carbon emission of Chongqing was in a state of continuous growth, which increased by 3826.65? 104t. The growth rate of the crop in 78.80%. cultivated land was both carbon emission and certain carbon absorption; the forest land was the main carbon sink in all land use types, and its carbon Absorptive capacity is the strongest in all land use types; grassland, water and unused land itself are carbon sequestration; construction land is the main carbon source, and its carbon emission intensity is far greater than that of other land types, which results in carbon emissions throughout Chongqing. (6) carbon emissions from various land use types in the future. In scenario 1, among the six types of carbon emissions in situation 1, cultivated land, water and construction land are still carbon sources, and the carbon emissions of construction land have increased rapidly over 10 years ago, and the rate of growth is up to 35.80%. The three types of woodland, grassland and unused land are all carbon sequestration. The growth of carbon emissions in construction land has reached an unprecedented peak, while other land types, whether carbon emissions or carbon absorption, are far from the overall impact of construction land on Chongqing's carbon emissions, which directly leads to a violent increase in the carbon emissions of the city of Chongqing in 2025. Situation 3 carbon and carbon sequestration is in phase. There is an increase and reduction in the implementation of the measures, but it is obvious that the carbon source of the construction land which has an almost absolute role in the whole region's carbon emissions is obviously weakened; the carbon emissions from the arable land and water are also relatively small, but the overall impact is limited; and the three types of land, the woodland, the grassland and the unused land, are the land types of the main carbon sequestration. With the promulgation and implementation of the relevant policies, the carbon absorption intensity is obviously enhanced. As a result of a large reduction in the intensity of the construction land carbon emission, the total carbon emissions increase in the situation 3 is the smallest, only 18.65%.

【学位授予单位】：重庆师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X24;F301.2

【参考文献】