气候变化与土地利用/覆被变化对中国北方农牧交错带水资源影响研究进展   总被引：1，自引：0，他引：1  

陈雪萍  赵学勇  王瑞雄  宁志英  卢建男  赵思腾 《中国沙漠》2022,42(3):170-177

中国北方农牧交错带对全球变化响应敏感,研究气候变化及土地利用/覆被变化（LUCC）背景下北方农牧交错带水资源问题,对变化环境下生态脆弱区的水资源利用与管理具有重要意义。通过对北方农牧交错带气候与LUCC演变特征及其对水资源影响等方面的综合研究,总结得出：（1） 近几十年,该地区气候呈暖干化趋势,气温升高速率与降水减少速率均高于全球平均水平。（2） LUCC以农牧相互转化为主,土地利用结构未发生明显变化。（3） 该地区流域径流、地下水位与气温负相关,与降水量正相关,且降水作用更明显;近几十年来,LUCC成为影响该地区生态水文过程的主导因素,对水资源影响的贡献率越来越大。同时,针对目前研究中存在的问题及薄弱环节,提出未来研究的发展趋势和亟需重点加强的研究方向。  相似文献   

耕地撂荒研究进展与展望   总被引：35，自引：5，他引：35  

李升发  李秀彬 《地理学报》2016,71(3):370-389

20世纪后半叶以来许多发达国家发生明显的耕地撂荒现象,并逐渐演变为全球性土地利用现象,深刻地改变了广大农村地区土地景观.本文以"土地利用变化--驱动机制--环境效应--政策响应"的框架系统梳理耕地撂荒主要研究进展.研究表明:① 全球耕地撂荒仍主要发生在欧美发达国家,但发展程度的区域差异很大;② 社会经济要素变化是耕地撂荒最主要驱动力,务农机会成本上升等原因引起的耕地边际化是撂荒发生的根本原因,而劳动力析出是造成耕地撂荒的直接原因;③ 耕地撂荒与否,撂荒程度以及撂荒地空间分布受村镇,农户,地块三个尺度的自然条件,劳动力特征,农业生产条件和区域社会经济条件等多方面因素的综合影响;④ 生态环境效应是当前撂荒效应研究的焦点,但该效应是以积极还是消极为主仍存争议;⑤ 增加农业补贴是当前减缓耕地撂荒的主要措施,但并非唯一和最合理的措施.未来,快速城镇化进程将促使中国耕地撂荒现象愈演愈烈,所以当前研究有待加强,本文认为应加强大范围耕地撂荒信息提取和监测,撂荒趋势预测和风险评估,社会经济效应评估及政策设计等方面研究.  相似文献   

Reconstructing provincial cropland area in eastern China during the early Yuan Dynasty (AD1271-1294)     

Meijiao LI  Fanneng HE  Fan YANG  Shicheng LI 《地理学报(英文版)》2018,28(12):1994-2006

Reconstructing historical land use and land cover change (LUCC) at the regional scale is an important component of global environmental change studies and of improving global historical land use datasets. By analyzing data in historical documents, including military-oriented cropland (hereafter M-cropland) area, the number of households engaged in M-cropland (hereafter M-household) reclamation, cropland area, and the number of households, we propose a conversion relationship between M-cropland area and cropland area reclaimed by each household. A provincial cropland area estimation method for the Yuan Dynasty is described and used to reconstruct the provincial cropland area for AD1290. Major findings are as follows. (1) Both the M-cropland and cropland areas of each household were high in the north and low in the south during the Yuan Dynasty, which resulted from different natural conditions and planting practices. Based on this observation, the government-allocated M-cropland reclamation area to each household was based on the cropland area reclaimed by each household. (2) The conversion relationship between M-cropland and cropland areas per household showed conversion coefficients of 1.23 and 0.65 for the south and north, respectively. (3) The cropland area in the entire study area in AD1290 was 535.4×10⁶ mu (Chinese area unit, 1 mu=666.7 m²), 57.8% in the north and 42.2% in the south. The fractional cropland areas for the entire study area, north, and south were 6.8%, 6.6%, and 7.1%, respectively and the per capita cropland areas for the whole study area, north, and south were 6.7, 15.6, and 4.1 mu, respectively. (4) Cropland was mainly distributed in the middle and lower reaches of the Yellow River (including the Fuli area), Huaihe River Basin (including Henan Province), and middle and lower reaches of the Yangtze River (including Jiangzhe, Jiangxi, and Huguang provinces).  相似文献   

Spatial features of land use/land cover change in the United States     

GAO Zhiqiang  LIU Jiyuan  DENG Xiangzheng 《地理学报》2003,13(1):63-70

With the classification data covering American land-use/land-cover (LUCC) with 30 m resolution from the project of National Land Cover Data (NLCD), we normalized them and made their resolution changed into 1 km ×1 km, created the data of American land-use grade and analyzed the spatial distribution and features of American LUCC as well as the influence of population and altitude on the land-use grade in light of methods of sampling analysis and correlation study. Based on the analysis, we concluded that forestry and grassland, accounting for 71.24% of the whole country, has taken the main part of American land cover, and besides, construction and arable land has occupied 19.22% of the total land, the rest of land cover types, including water area, wetland and underdeveloped land, is 9.54% of the country's total. The developing potential of American land resources is enormous with less destroyed and disturbed ecological environment. Although, in some sense, the population and altitude influence the spatial variation of American land-use grade respectively, the influence of spatial variation of altitude and population density on that of land-use grade is not significanct.  相似文献   

土地利用对岩溶作用碳汇的影响研究综述   总被引：6，自引：4，他引：2  

曾思博  蒋勇军 《中国岩溶》2016,35(2):153-163

耦合水生光合作用的岩溶作用碳汇新模式的提出使得碳酸盐岩的风化过程成为寻找“陆地剩余碳汇”(residual land sink) 的新方向。传统意义上,碳酸盐岩风化在全球碳循环模型中被认为是未快速响应地表环境变化的地质过程,然而最新一系列研究表明人类土地利用显著改变了这一地质循环过程。文章总结了岩溶作用碳汇对不同土地利用/覆被变化的具体响应,并对其机理进行了系统分析。发现土地利用与覆被变化影响岩溶作用碳循环过程主要源自土壤CO2浓度和径流量变化以及外源酸（硝酸和硫酸）的介入。证据显示在土地利用对岩溶作用碳汇的调控中土壤CO2浓度与径流量是复杂且相互制约的两个机制,人类活动产生的外源酸干扰在不同层面上的影响也不同。由于地表水生生态系统所产生的内源有机碳（AOC）的巨大稳碳能力(水生碳泵效应)在以往的研究中并没有与碳酸盐岩风化过程相联系,因而其对土地利用变化的响应过程和机理是岩溶碳循环研究的最新方向。基于土地利用调控碳酸盐岩风化过程的复杂性和多样性特点,综合考虑岩溶作用产生的DIC(溶解无机碳)与AOC在不同土地利用情况下的相互关系以及定量分析各环境因素的具体效应成为了合理制定人为土地利用调控策略的必要前提,也是岩溶作用碳汇研究的未来发展方向。   相似文献   

区域尺度土地利用/土地覆盖变化对气温日较差的影响     

华文剑  陈海山 《气候变化研究进展》2013,9(2):117-122

利用NCAR CAM4.0模式,针对潜在植被和当代植被两种典型土地覆盖类型,通过平衡态试验探讨土地利用/土地覆盖变化（land use/land cover change, LUCC）对气候的影响。结果表明,LUCC对气温日较差有明显影响。日较差的响应与LUCC变化的区域有紧密的联系。在中纬度,LUCC引起日较差减小,这主要由日最高气温的降低造成。在低纬度东亚地区,日较差的减小主要由日最高气温的降低造成;而在印度半岛,日较差的减小主要由日最低气温的升高决定。这种区域性的差异,主要是由于植被蒸腾和冠层蒸发的作用,LUCC能够显著调节气温日较差的变化。  相似文献   

关中-天水经济区土地利用变化对净第一性生产力影响测评          下载免费PDF全文

周自翔  李晶  韩艳飞 《干旱区地理》2013,36(6):1058-1066

净第一性生产力是表现陆地生态过程的关键参数,土地利用变化深刻影响区域的净第一性生产力。选取关中-天水经济区为研究区域,尝试对30 m精度的1980-2011年4期9月份左右Landsat 7的遥感影像以及CASA模型来估算关中-天水经济区的净第一性生产力,并用2011年遥感图像解译获得该年的土地利用数据,以及土地利用变化情况。在此基础上分析土地利用变化对净第一性生产力的影响,并且对关天经济区各县市净初级生产力进行了对比和分析。结果表明：1980-2011年,关中-天水经济区土地利用耕地、林地、居民建筑用地变化明显,南部秦岭山区多为林地与草地,净第一性生产力高达625.37 g C·m-2·a-1,而关中平原与天水地区人口居住区与开垦区净第一性生产力明显下降,最低达47.78 g C·m-2·a-1,人为的开发与利用土地降低了区域的净第一性生产力。所以,要继续施行落实退耕还林政策,控制城镇用地较大速度的扩增,以保持好区域的生态服务功能。  相似文献   

黄河三角洲土地利用/覆被变化时空特征研究   总被引：3，自引：0，他引：3  

李静  赵庚星  杨佩国  马淑惠 《地域研究与开发》2008,27(6)

黄河三角洲地区受人类活动作用时间相对较短,为土地利用/覆被变化及其驱动力研究提供了难得的条件.以位于黄河入海口处的垦利县为例,通过对1987-2000年土地利用/覆被变化幅度、变化构成以及流向图的分析,得到了该地区土地利用/覆被变化的特点,并应用遥感及GIS空间分析手段分析了黄河、渤海对该区土地利用/覆被变化格局的影响与作用机制.结果表明:(1)位于黄河入海口处的垦利县土地生态环境脆弱,占土地总面积80%的旱地、林草地、盐荒地和滩涂存在状态不稳定,盐荒地是其土地利用/覆被变化的核心类型;(2)黄河淡水和海洋咸水所控制的水文条件变化是该区土地利用/覆被变化的重要驱动因素,基本控制了分布的格局,并影响土地利用/覆被变化的可能性及变化方向.  相似文献   

The impact of land use/cover change on storage and quality of soil organic carbon in midsubtropical mountainous area of southern China     

YANG Yusheng  XIE Jinsheng  SHENG Hao  CHEN Guangshui  LI Xu  YANG Zhijie 《地理学报》2009,19(1):49-57

Land use/cover change (LUCC) is widely recognized as one of the most important driving forces of global carbon cycles. The influence of converting native forest into plantations, secondary forest, orchard and arable land on stores and quality of soil organic carbon (SOC) was investigated in mid-subtropical mountainous area of southern China. The results showed that LUCC had led to great decreases in SOC stocks and quality. Considerable SOC and light-fraction organic carbon (LFOC) had been stored in the native forest (142.2 t hm?2 and 14.8 t hm?2 respectively). When the native forest was converted to plantations, secondary forest, orchard and arable land, the SOC stocks decreased by 25.6%, 28.7%, 38.0%, 31.8% and 51.2%, respectively. The LFOC stocks decreased by 52.2% to 57.2% when the native forest was converted to woodland plantations and secondary forest, and by 82.1% to 84.2% when converted to economic plantation, orchard and arable land. After the conversion, the ratios of LFOC to SOC (0–60 cm) decreased from 13.3% to about 3.0% to 10.7%. The SOC and LFOC stored at the upper 20 cm were more sensitive to LUCC when compared to the subsurface soil layer. Also, the decline in carbon storage induced by LUCC was greater than the global average level, it could be explained by the vulnerable natural environment and special human management practices. Thus, it is wise to enhance soil carbon sequestration, mitigate elevated atmospheric co2 and develop ecological services by protecting vulnerable environment, restoring vegetation coverage, and afforesting in mountainous area in mid-subtropics.  相似文献   

中亚热带山区土地利用变化对土壤有机碳储量和质量的影响   总被引：3，自引：0，他引：3  

杨玉盛  谢锦升  盛浩  陈光水  李旭  杨智杰 《地理学报(英文版)》2009,19(1):49-57

Land use/cover change (LUCC) is widely recognized as one of the most important driving forces of global carbon cycles. The influence of converting native forest into plantations, secondary forest, orchard and arable land on stores and quality of soil organic carbon (SOC) was investigated in mid-subtropical mountainous area of southern China. The results showed that LUCC had led to great decreases in SOC stocks and quality. Considerable SOC and light-fraction organic carbon (LFOC) had been stored in the native forest (142.2 t hm⁻² and 14.8 t hm⁻² respectively). When the native forest was converted to plantations, secondary forest, orchard and arable land, the SOC stocks decreased by 25.6%, 28.7%, 38.0%, 31.8% and 51.2%, respectively. The LFOC stocks decreased by 52.2% to 57.2% when the native forest was converted to woodland plantations and secondary forest, and by 82.1% to 84.2% when converted to economic plantation, orchard and arable land. After the conversion, the ratios of LFOC to SOC (0–60 cm) decreased from 13.3% to about 3.0% to 10.7%. The SOC and LFOC stored at the upper 20 cm were more sensitive to LUCC when compared to the subsurface soil layer. Also, the decline in carbon storage induced by LUCC was greater than the global average level, it could be explained by the vulnerable natural environment and special human management practices. Thus, it is wise to enhance soil carbon sequestration, mitigate elevated atmospheric CO₂ and develop ecological services by protecting vulnerable environment, restoring vegetation coverage, and afforesting in mountainous area in mid-subtropics. Foundation: Supported by the Key Project of Ministry of Education of China, No.JA04166 Author: Yang Yusheng (1964–), Professor, specialized in carbon and nitrogen cycles of forest.  相似文献