疏勒河中游土地利用动态变化分析

以疏勒河中游为研究区,利用ArcGIS9.2和ERDAS9.1平台,对1990年、2000年和2010年3期Landsat TM遥感影像进行目视解译,获取流域20年间土地利用/覆被变化遥感资料,通过土地利用动态度方法,分析流域20年主要土地利用类型的数量变化和土地利用/覆被变化的驱动力。结果表明:(1)1990-2010年间,疏勒河中游地区土地覆被类型主要为未利用地、牧草地、耕地,三者面积占研究区总面积的98.22%,20年间土地利用整体特征并未发生重大变化。(2)疏勒河中游主要土地利用类型变化发生在耕地、建设用地和牧草地,其土地利用动态度分别为13.60%、7.97%和7.68%。(3)政策和人口增长可能是促进土地利用/覆被变化的主要驱动因素。     

Land cover change and eco-environmental quality response of different geomorphic units on the Chinese Loess Plateau

Land cover in the Chinese Loess Plateau has undergone dramatic changes since the late 1980s.Revealing the trend in land cover change and eco-environmental quality response of different geomorphic units in this stage is a realistic requirement for promoting sustainable development of the Chinese Loess Plateau.Based on the data of geomorphic units and land cover in 1990,2000,2010 and 2018 of the Chinese Loess Plateau,we studied the trend of land cover change and eco-environmental quality response of different geomorphic units by using a significance index of land cover change,a proportion index of land cover change and an eco-environmental response model.The results indicated that from 1990 to 2018,the areas of forestland and construction land substantially increased,whereas those of cropland,grassland,wetland and unused land considerably decreased.Land cover change exhibited large geomorphic differences,and the main conversion of land cover was from cropland into other land types.Unstable trend of land cover change in the loess tablelands and sandy loess hills declined,whereas the unstable trends in the other geomorphic units enhanced.Eco-environmental quality varied among different geomorphic units.The expansion of construction land and degradation of forestland,grassland and wetland resulted in the deterioration of eco-environmental quality.The conversion of cropland and unused land into forestland and grassland,and the conversion of grassland into forestland were the main factors that drove the improvement of eco-environmental quality.The findings of this study may provide theoretical reference and support decision making for the optimization of land use structure and the improvement of eco-environmental quality on the Chinese Loess Plateau.     

Land use/land cover change responses to ecological water conveyance in the lower reaches of Tarim River,China

The Tarim River is the longest inland river in China and is considered as an important river to protect the oasis economy and environment of the Tarim Basin. However, excessive exploitation and over-utilization of natural resources, particularly water resources, have triggered a series of ecological and environmental problems, such as the reduction in the volume of water in the main river, deterioration of water quality, drying up of downstream rivers, degradation of vegetation, and land desertification. In this study, the land use/land cover change (LUCC) responses to ecological water conveyance in the lower reaches of the Tarim River were investigated using ENVI (Environment for Visualizing Images) and GIS (Geographic Information System) data analysis software for the period of 1990-2018. Multi-temporal remote sensing images and ecological water conveyance data from 1990 to 2018 were used. The results indicate that LUCC covered an area of 2644.34 km² during this period, accounting for 15.79% of the total study area. From 1990 to 2018, wetland, farmland, forestland, and artificial surfaces increased by 533.42 km² (216.77%), 446.68 km² (123.66%), 284.55 km² (5.67%), and 57.51 km² (217.96%), respectively, whereas areas covered by grassland and other land use/land cover types, such as Gobi, bare soil, and deserts, decreased by 103.34 km² (14.31%) and 1218.83 km² (11.75%), respectively. Vegetation area decreased first and then increased, with the order of 2010<2000<1990<2018. LUCC in the overflow and stagnant areas in the lower reaches of the Tarim River was mainly characterized by fragmentation, irregularity, and complexity. By analyzing the LUCC responses to 19 rounds of ecological water conveyance in the lower reaches of the Tarim River from 2000 to the end of 2018, we proposed guidelines for the rational development and utilization of water and soil resources and formulation of strategies for the sustainable development of the lower reaches of the Tarim River. This study provides scientific guidance for optimal scheduling of water resources in the region.     

Response of ecosystem service value to land use/cover change in the northern slope economic belt of the Tianshan Mountains,Xinjiang, China

Land use/cover change (LUCC) is becoming more and more frequent and extensive as a result of human activities, and is expected to have a major impact on human welfare by altering ecosystem service value (ESV). In this study, we utilized remote sensing images and statistical data to explore the spatial-temporal changes of land use/cover types and ESV in the northern slope economic belt of the Tianshan Mountains in Xinjiang Uygur Autonomous Region, China from 1975 to 2018. During the study period, LUCC in the study region varied significantly. Except grassland and unused land, all the other land use/cover types (cultivated land, forestland, waterbody, and construction land) increased in areas. From 1975 to 2018, the spatial-temporal variations in ESV were also pronounced. The total ESV decreased by 4.00×10⁸ CNY, which was primarily due to the reductions in the areas of grassland and unused land. Waterbody had a much higher ESV than the other land use/cover types. Ultimately, understanding the impact of LUCC on ESV and the interactions among ESV of different land use/cover types will help improve existing land use policies and provide scientific basis for developing new conservation strategies for ecologically fragile areas.     

1977-2013年疏勒河中下游土地利用变化与环境响应

以甘肃省疏勒河中下游为研究对象,利用1977、1986、1993、2002年和2013年5期遥感解译影像获取土地利用变化数据,通过土地利用类型面积转移矩阵、区域环境质量指数、土地利用类型转换的生态贡献率等方法,定量研究了1977-2013年疏勒河土地利用变化过程及其生态环境响应.结果表明:①1977-2013年,疏勒河土地利用变化以耕地、草地和未利用地的相互转换为主.与1977年相比:耕地、水域和建设用地面积分别增加了921.52km2、75.6 km2、74.18 km2,林地、草地和未利用地面积分别减少了79.27 km2、253.46 km2和738.55 km2.②1977-2013年,疏勒河中下游环境质量整体呈现出恶化一改善一改善一改善的态势,区域内部同时存在着恶化一改善的双向演替趋势.③草地、林地和水域的退化是区域环境质量恶化的主导因素,未利用地转换为草地及草地转化为水域是区域环境质量改善的主要因素.     

玛纳斯河流域耕地时空变化及其生态环境效应

以干旱区典型流域-玛纳斯河流域为研究区,利用1976、1989、20005年三期遥感影像结合G IS软件,探查近30年玛纳斯河流域耕地时空变化及其生态环境效应。结果表明:该流域耕地资源在时间和空间上都发生了较大的变化。耕地总量在不断增加,由1976年3418.71km2增至2005年5907.62km2,且1989~2005年间耕地年均增长较1976~1989年更快。矩阵分析则表明了耕地的增加是依靠开垦草地与盐碱地。耕地的减少主要是由于建设占用耕地、耕地撂荒转变为盐碱地或沙地以及退耕还林。空间上流域耕地范围扩大,在绿洲区分布趋于连片,而绿洲边缘的耕地破碎性有所增强,耕地成为流域最主要的景观。由于耕地的不断扩大,致使流域生态环境发生了剧烈的变化,出现了如尾闾湖干涸、草场退化、土地退化、生物多样性降低等一系列的生态环境问题。     

新疆和田河流域土地利用及其生态服务价值变化

土地利用结构决定土地生态系统服务价值,生态服务价值也反映了土地利用结构的生态优劣.基于遥感和GIS技术及数理统计学方法,利用1990年、1999年、2002年和2005年遥感影像解译得到的4期土地利用数据,对和田河流域1990-2005年土地利用变化进行定量分析,估算出研究区15年间的生态服务价值变化量.结果表明:①耕地、林地和城乡建设用地面积增加,草地、水域和未利用地面积减少;研究区土地利用处于发展时期,土地利用综合程度日益提高;优势度没有发生明显的变化,未利用地一直最高.②土地生态系统服务价值量有所增加,土地利用总体生态效应趋良.但环境也存在着局部恶化,主要表现在上游山地生态系统冰川退缩、天然植被退化;中游绿洲生态系统耕地扩张迅速,土壤盐渍化,人工渠、水库增加显著;下游荒漠生态系统植被退化,水资源严重不足,土地沙漠化.     

Streamflow responses to climate change and LUCC in a semi-arid watershed of Chinese Loess Plateau

Climate change and Land Use/Cover Change(LUCC) have been identified as two primary factors affecting watershed hydrological regime. This study analyzed the trends of streamflow, precipitation, air temperature and potential evapotranspiration(PET) from 1962 to 2008 in the Jihe watershed in northwestern Loess Plateau of China using the Mann-Kendall test. The streamflow responses to climate change and LUCC were quantified independently by the elasticity method. The results show that the streamflow presented a dramatic decline with a turning point occurred in 1971, while the precipitation and PET did not change significantly. The results also show that the temperature rose markedly especially since 1990 s with an approximate increase of 1.74°C over the entire research period(1962–2008). Using land use transition matrix, we found that slope cropland was significantly converted to terrace between 1970 s and 1990 s and that forest cover increased relatively significantly because of the Grain for Green Project after 2000. The streamflow reduction was predominantly caused by LUCC and its contribution reached up to 90.2%, while the contribution of climate change to streamflow decline was only 9.8%. Although the analytical results between the elasticity method and linear regression model were not satisfactorily consistent, they both indicated that LUCC(human activity) was the major factor causing streamflow decline in the Jihe watershed from 1962 to 2008.     

松嫩平原西部农牧交错区土地利用变化及驱动力分析——以吉林省通榆县为例

选取吉林省通榆县为研究区,以1986年-2006年4期遥感影像为基础数据源,在GIS技术支持下,分析近20年来农牧交错区土地利用变化的时空动态特征,结合气象、人口等多源数据资料解析县域土地利用变化的自然和人文驱动力。结果表明:耕地、草地和盐碱地是通榆县土地利用的主要类型,近20年来,耕地面积增加了近53%,草地面积则减少了1165km2,耕地与草地的相互转化是研究区内土地利用变化的主要过程;区域土地利用变化的速度是明显减缓的;耕地以向周围区域扩展的方式不断增加,分布于中部和南部、西北部的草地则连片消失;气候、土壤、植被和水文地质等自然环境条件是区域土地利用格局形成的基础,人口增长、土地利用政策和不合理的开发活动等人为因素则是影响和控制区域土地利用变化方向的主导驱动力。     

Hydrological response to land use and land cover changes in a sub-watershed of West Liaohe River Basin,China

In recent years, the streamflow of the Laohahe Basin in China showed a dramatic decrease during the rainy season as a result of climate change and/or human activities. The objective of this work was to document significant streamflow changes caused by land use and land cover （LULC） changes and to quantify the impacts of the observed changes in Laohahe Basin. in the study area, the observed streamflow has been influenced by LULC changes, dams, and irrigation from rivers, industry, livestock and human consumption. Most importantly, the growth of population and gross domestic product （GDP） accompanied by the growth in industrial and agricultural activities, which led to LULC changes with increased residential land and cropland and decreased grassland since 2000s. Statistical methods and Variable Infiltration Capacity （VIC） hydrological model were used to estimate the effects of climate change and LULC changes on streamflow and evaportranspiration lET）. First, the streamflow data of the study area were divided into three sub-periods according to the Pettitt test. The hydrological process was then simulated by VIC model from 1964 to 2009. Furthermore, we compared the simulated results based on land use scenarios in 1989, 1999 and 2007, respectively for exploring the effect of LULC changes on the spatio-temporal distribution of streamflow and ET in the Laohahe Basin. The results suggest that, accompanied with climate change, the LULC changes and human water consumption appeared to be the most likely factors contributing to the sig- nificant reduction in streamflow in the Laohahe Basin by 64% from1999 to 2009.     

黄河中上游部分地区土地覆盖动态变化研究

作为美国国家科学基金项目"中国生态恢复综合影响评价"的部分研究结果,对项目选定的四个评价区之一的黄河中上游地区的研究区域进行土地利用和覆盖变化研究,并以此评价退耕还林效果。利用覆盖研究区域的卫星遥感图像进行解译,以便获取研究区域土地利用和土地覆盖变化(LUCC)的历史数据,特别是大于25度坡度的LUCC以及退耕前后的LUCC数据,通过这些解译数据评价研究区域的退耕还林效果。解译后的数据显示退耕还林效果良好。选定24景跨20年(1978年至2007年)的Landsat遥感卫星图像数据,通过解译追踪研究区域LUCC历史演变,来判断退耕还林的执行效果。     

南疆典型绿洲土地利用空间格局变化特征分析——以疏勒县为例

利用新疆疏勒县三期遥感影像解译得到的数据,对疏勒县土地利用空间格局变化进行深入分析。分析结果表明:(1)研究区内耕地、林地、草地和建设用地四者之和面积占该区总面积的52.97%,盐碱地和沙地等未利用地占44.35%。1990～2006年间,林地、草地、建设用地面积大幅度增加;盐碱地和沙地面积大幅度减少。其充分说明人类活动对土地利用/覆被类型变化影响越来越强烈。(2)研究区土地利用/覆被类型转移的主要方向是耕地转化为林地和草地,草地和沙地转化为耕地,耕地和草地转化为建设用地,草地转化为沙地。土地利用变化经历了"显著变化-缓慢变化-显著变化"的过程。(3)景观格局分析表明,在人类活动的影响下,研究区景观破碎度、多样性增大,优势度减小。驱动力分析表明,人口增长和经济发展因素是研究区土地利用/覆被变化的最直接驱动力,同时还受产业结构和政策因素及人类干扰强度的影响。     

咸阳市土地利用变化及生态风险

基于1990年与2007年2期土地利用遥感数据,采用RS,GIS技术和统计分析方法,对咸阳市1990-2007年的土地利用变化状况进行了分析,在此基础上,研究了由土地利用变化引起的咸阳市生态风险问题。结果表明：①17 a间咸阳市土地利用整体呈现耕地面积和未利用地面积减少,林地、草地、建设用地面积增加的趋势;②生态风险指...     

近10年塔里木河流域土地利用/土地覆被变化与人口因素关系研究

根据1990年、2000年两期土地利用现状图,运用地理信息系统软件ArcInfo、Arcview以及统计软件,提取、分析塔里木河流域41个县市1990-2000年土地利用/土地覆被的时空变化(LUCC)情况和土地利用程度综合指数。运用SPSS等统计软件,分析并建立土地利用程度人口分异模型,探讨了该研究区LUCC与人口因素的关系。此模型不仅可用于现阶段研究区LUCC分析,还可以根据人口变化趋势进行土地利用程度的变化趋势分析。这对塔河流域土地资源的有效利用和管理具有积极的意义。     

黑河中游张掖市土地利用/覆盖变化的水文水资源效应分析

本文通过对张掖市1981年、1990年、1996年及2003年土地利用情况的分析,发现随着张掖市土地利用/覆盖的变化,研究区产生了一系列的水文水资源效应。首先,随着农田有效灌溉面积的增大,地表年耗水量从1980年的6.78×108m3增加到1999年的9.21×108m3,导致正义峡的下泻水量逐年减少,下游生态与环境急剧退化。其次使区内的蒸发格局发生变化,土地利用/覆盖变化强度较大的甘州区、临泽县和高台县年蒸散量呈下降趋势;而土地利用/覆盖变化强度较小的山丹县、民乐县和肃南县年蒸散量变化趋势不太明显。再次,由于城镇用地及工农业用地扩展,导致大量的地表水和地下水被超量开采,结果使地下水位降低,泉水溢出量减少;与此同时,工业、农业及人民生活造成的污染物使水质急剧恶化,给绿洲生态和经济可持续发展构成了严重威胁。     

干旱地区土地利用/土地覆盖变化研究——以黑河流域为例

土地利用/土地覆盖变化作为国际上全球变化研究的前沿与热点课题,是所有可持续发展相关问题的核心。区域案例研究是土地利用/土地覆盖变化研究的重要方法。本文以位于西北内陆干旱地区的黑河流域为例,阐明该流域土地利用/土地覆盖变化的过程,揭示其土地利用/土地覆盖变化的动力机制,分析土地利用/土地覆盖变化对该流域自然环境与社会经济的影响,从而提出该流域土地可持续利用对策。     

基于分形理论的车尔臣河流域中下游土地利用动态变化

土地利用变化是全球变化的重要内容和主要表现之一,该研究已成为全球变化研究的前沿和热点问题。土地利用变化一方面与自然环境演变相关,另一方面与人类活动的不断增强密切相关。文中以车尔臣河流域中下游为例,在遥感和地理信息系统的支持下,通过对1970年、1990年、2000年和2005年遥感图像的解译,获取研究区四个时期土地利用...     

Scenario simulation of water retention services under land use/cover and climate changes: a case study of the Loess Plateau,China

Comprehensive assessments of ecosystem services in environments under the influences of human activities and climate change are critical for sustainable regional ecosystem management. Therefore, integrated interdisciplinary modelling has become a major focus of ecosystem service assessment. In this study, we established a model that integrates land use/cover change (LUCC), climate change, and water retention services to evaluate the spatial and temporal variations of water retention services in the Loess Plateau of China in the historical period (2000-2015) and in the future (2020-2050). An improved Markov-Cellular Automata (Markov-CA) model was used to simulate land use/land cover patterns, and ArcGIS 10.2 software was used to simulate and assess water retention services from 2000 to 2050 under six combined scenarios, including three land use/land cover scenarios (historical scenario (HS), ecological protection scenario (EPS), and urban expansion scenario (UES)) and two climate change scenarios (RCP4.5 and RCP8.5, where RCP is the representative concentration pathway). LUCCs in the historical period (2000-2015) and in the future (2020-2050) are dominated by transformations among agricultural land, urban land and grassland. Urban land under UES increased significantly by 0.63×10³ km²/a, which was higher than the increase of urban land under HS and EPS. In the Loess Plateau, water yield decreased by 17.20×10⁶ mm and water retention increased by 0.09×10⁶ mm in the historical period (2000-2015), especially in the Interior drainage zone and its surrounding areas. In the future (2020-2050), the pixel means of water yield is higher under RCP4.5 scenario (96.63 mm) than under RCP8.5 scenario (95.46 mm), and the pixel means of water retention is higher under RCP4.5 scenario (1.95 mm) than under RCP8.5 scenario (1.38 mm). RCP4.5-EPS shows the highest total water retention capacity on the plateau scale among the six combined scenarios, with the value of 1.27×10⁶ mm. Ecological restoration projects in the Loess Plateau have enhanced soil and water retention. However, more attention needs to be paid not only to the simultaneous increase in water retention services and evapotranspiration but also to the type and layout of restored vegetation. Furthermore, urbanization needs to be controlled to prevent uncontrollable LUCCs and climate change. Our findings provide reference data for the regional water and land resources management and the sustainable development of socio-ecological systems in the Loess Plateau under LUCC and climate change scenarios.     

黄河源区土地利用和景观格局变化及其生态环境效应

基于TM/ETM卫星遥感数据,运用ArcInfo软件和景观生态学方法,对黄河源区1986～2000年土地利用和景观结构的时空变化特征进行了研究。结果表明:源区林地、湿地、草地和冰川面积减少,建设用地、耕地和未利用土地面积显著增加,土地综合利用程度下降。景观破碎化程度加剧,分维数和多样性指数增加,优势度提高,景观异质性增强。黄河源区脆弱的生态体系对土地利用变化响应强烈,造成水土流失与沙漠化程度加剧,导致大范围高寒草甸、草原植被退化,湿地萎缩。区域气候变化及其引起的冻土环境退化,以及所叠加的不合理的人类经济活动和较为严重的鼠虫害是黄河源区生态环境急剧恶化的主要成因。     

土地利用变化时空特征与区域发展关系研究——以渭干河流域为例

基于三期遥感影像图,通过土地利用相对变化率、净变化速度和土地利用程度综合指数等,分析渭干河流域近20年土地利用变化与利用程度的时空差异,并探讨土地利用程度与社会经济发展水平的关系。研究结论如下:(1)渭干河流域土地利用类型以草地和未利用地为主,其类型分布和面积变化存在时空差异。1990—2008年流域林地、水域、建设用地面积逐渐增加,草地、沼泽、未利用地有所减少,耕地面积先增后减,总体有所增加。(2)因未利用地面积比重较大,流域各县的土地利用程度普遍不高,但近年有明显提高。库车、沙雅、新和三县土地利用程度综合指数逐渐增长,拜城县先增后减,总体有所增长。流域各县的土地利用效益均逐年增长,后期增长率远大于前期。(3)土地利用程度与区域社会经济发展水平存在正相关,土地利用程度综合指数越高,单位面积GDP和空间城市化水平越高。未利用地面积比重的空间差异对各县市城市化水平之间的差异具有较大影响。(4)人类活动加剧、社会经济发展等因子是流域土地利用变化主要驱动因素。