文峪河流域土地利用/覆被变化及其驱动力分析

土地利用/覆被变化对于区域的自然、经济和生态发展有着深刻的影响,土地变化驱动力研究是土地利用/覆被变化的核心问题之一。为了探讨中西部小流域的土地覆被变化特征及其驱动因子组成与驱动方式,以山西省文峪河流域为研究对象,基于RS与GIS平台,分析流域2000—2018年土地利用/覆被变化情况;利用马尔柯夫模型预测未来土地利用结构;选取自然因子、区位建设因子、社会经济因子,利用Logistic回归的建模方法分析流域的土地利用/覆被驱动力。结果表明,流域整体耕地、林地、草地面积有所减少,水域、建设用地、其他用地类型面积增加,不同地类的变化速度、土地转移情况不同,流域整体土地变化速度较快,利用程度提高,有序化程度下降,均匀度增加。预测结果显示,耕地、林地、草地、其他用地面积下降,水域、建设用地面积增加,除耕地、建设用地外,其余地类面积变化较小。自然因子、区位建设因子和社会经济因子对研究区土地利用/覆被变化都具有显著的驱动作用。流域的土地利用/覆被在过去18年间经历了快速、复杂的变化,自然因子对土地变化具有基础性、长远性的影响,短时间尺度上区位建设因子与社会经济因子是影响土地变化的主要驱动力量。     

乌鲁木齐市土地利用/覆被变化及生态安全评价

乌鲁木齐市是坐落在绿洲上的城市,城市的生态环境较为脆弱。通过对城市土地利用/覆被变化及土地生态安全进行评价,揭示乌鲁木齐市1990—2017年间土地利用/覆被变化的规律、生态安全变化趋势。借助ERDAS和ArcGIS软件对乌鲁木齐市4期遥感图像进行解译分析,利用物元模型对乌鲁木齐市的土地生态安全现状进行评价。结果表明:1990—2017年乌鲁木齐市土地利用/覆被变化是以耕地、林地以及草地的转出和建设用地、未利用地的转入为主;各时段总体的土地利用/覆被变化呈现良好的发展态势且正处在发展期;乌鲁木齐市土地生态安全程度由不安全增长较安全水平。通过分析乌鲁木齐市土地利用/覆被变化情况及生态安全进行评价,为未来解决城市发展过程中所带来的诸多土地生态环境问题具有重要意义。     

“3S”技术支持下的成都市土地利用与土地覆盖变化（LUCC）研究

以LUCC理论为出发点,应用＂3S＂技术,建立土地利用变化数据库,并运用数理统计方法研究了成都市2000-2005年土地利用/覆被变化及其驱动力。研究结果表明：建设用地动态度最大,土地利用转移方向表现为大面积耕地转化为建设用地;政策、人口和经济为城市土地利用/覆被变化的主要驱动力,其中,城市化水平对GDP贡献较大,而经济非农化率贡献较小。     

咸阳市礼泉县土地利用覆被变化及其驱动力研究

土地利用覆被变化及其驱动力研究是当前的热点问题,主要研究内容为土地利用类型的变化规律、自然驱动力以及人类活动对土地利用变化的影响作用。通过对局部或区域的个例研究,可以详细地说明土地利用覆被变化与环境因素及人文社会因素之间的相互关系。本文选取了渭北高原地区南部的礼泉县作为研究对象,以2005、2010、2015年三期TM遥感影像作为数据源,利用遥感技术,运用GIS软件,对研究区域分别从土地利用类型的数量变化、土地利用变化的速度、土地利用类型多样性分析、土地利用程度变化等方面对土地利用覆被变化的过程进行了分析。在此基础上,结合当地自然因素及其社会经济统计指标,运用定性分析的办法,重点对引起礼泉县土地利用变化的人文驱动因子进行了分析。     

北京山区林地变化与社会经济驱动力研究

依据土地利用详查数据和社会经济统计数据,通过分析北京山区近10年林地时空变化特征,借助土地利用/覆被变化(LUCC)驱动力分析方法,定量诊断出北京山区林地变化的主导社会经济驱动力,目的在于系统揭示北京山区林地变化的原因和社会经济驱动机制,为北京山区林地资源的保护和发展提供理论指导。     

东营市土地利用/覆被变化分析及驱动力研究

综合利用RS及GIS方法,以东营市1992、2000及2010年TM/ETM+遥感影像为基础,分析了东营市18年间土地利用时空演变的情况及驱动机制。结果表明:东营市土地利用/覆被变化在2000～2010年间最为显著,1992～2000年间变化不显著;滨海地区、内陆经济发达地区为土地利用变化发生的主要区域;监测期内,研究区景观要素类型相互转化较为频繁,主要表现为耕地转为建设用地,草地转为耕地,未利用地及滩涂转为盐田虾塘;人口、经济增长及城镇化是该区域土地利用/覆盖变化的主要驱动因子。     

云南大石林风景区景观格局变化研究

风景游览区土地利用/覆被变化与景观演变是自然保护与风景旅游业协调发展状况的直接表现。以云南石林世界自然遗产地的大石林景区为例,应用遥感技术和GIS空间分析技术,分析了1990年和2006年土地利用/覆被与景观格局变化。结果表明,天然灌草在研究期内减少了近50%,耕地减少了7.81%,石林地减少了4.15%,云南松林、交通用地、水体、建筑、滇青冈林、柏树林、人工草地、香樟树林8种景观类型均有所增加。景观类型呈现出不稳定和频繁变化的特点,地类间的转化呈多向交叉转移转化,除建筑、水体、滇青冈林保有率较高外,其余各地类均有超过50%的比重发生转入和转出。景观间的连通性降低,多样性增加,异质性增强。     

森林土壤N_2O产生与排放影响因子研究进展

影响森林土壤N2O产生和排放的主要因子为土壤理化性质(如土壤温度、土壤含水量、pH值以及土壤C/N等),同时,森林类型以及环境干扰(如氮沉降、土地利用/土地覆被变化等)也会影响土壤N2O产生和排放。文中首先论述了土壤N2O产生机制,然后综述了目前国内外关于上述影响因子对土壤N2O产生和排放影响的研究结果,最后提出未来应重点研究的方向。     

滇池流域土地利用动态变化分析

在RS和GIS的支持下,获取了滇池流域1998年、2002年及2010年的土地利用分类图,通过土地利用动态度方法,分析了流域22年间土地利用类型的数量变化。结果表明：耕地和建设用地主要沿滇池分布,林地面积所占比例较大;土地利用类型变化主要发生在耕地、未利用地、建设用地,其土地利用动态度分别为1．598％、2．698％和9．021％;人口增长和经济的快速发展是滇池流域土地利用／覆被变化的主要驱动力。     

北京市永定河流域土地利用/覆盖变化研究

借助于遥感和地理信息技术,以永定河(北京段)流域1978、1988、1999、2004、2005年5期TM遥感影像为主要数据源,结合若干地形数据库资料,统计永定河31年间水域、草地、耕地、林地、建筑用地、未利用地六大土地类型的面积变化情况,通过分析单一土地利用平均动态度、单一土地利用平均转出率和转入率等指标,对永定河(北京段)流域土地利用/覆被变化的格局与过程进行了定量研究.结果表明:①31年间,永定河(北京段)流域的土地利用/覆盖面积呈现一定程度的波动.1978~2004年各类面积占总面积的比例由大到小为有林地>耕地>建筑用地>水域>未利用地>草地;2004~2009年比例变化为有林地>耕地>建筑用地>未利用地>水域>草地.②在1978~2009年间,水域、未利用地、建筑用地3个土地类型转化比较剧烈;草地在1988~2004年间变化幅度大,转入、转出率较高;耕地减少;林地则呈现增加态势.     

Land use/land cover change dynamics and drivers in a low-grade marginal coffee growing region of Veracruz,Mexico

In the state of Veracruz, Mexico, lowland and marginal coffee growing regions have been particularly vulnerable since the 1989 coffee crisis. Government programs have promoted production diversification as a strategy to improve local incomes and conserve environmentally beneficial shade-tree coffee agroforests. We present results on land use/land cover dynamics in the municipality of Zozocolco de Hidalgo from 1973 to 2006. The municipality is recognized for its indigenous population and poverty, and currently, diversification efforts are being implemented. Our study combines remote sensing and GIS analyses, binary logistic regression and econometric modeling, as well as socioeconomic surveys to evaluate land use/land cover change (LULCC) dynamics and explore potential environmental and socioeconomic drivers. Results show that tree cover and coffee agroforests had largely been conserved during the first decade after the coffee crisis. But, recent trends indicate loss of tree cover in coffee agroforests and their conversion mostly to pasture. Land use/land cover drivers are largely explained by spatially explicit environmental variables such as slope and elevation. Relevant socioeconomic variables such as distance to markets and land use profitability were not significantly related to land use changes in Zozocolco. Surveys revealed that many households had converted coffee agroforests to pasture or agriculture in the past decade and others intended on renting or selling their agroforest plots, mostly for conversion to pasture. Diversification programs may not be sufficient to stem deforestation in lowland and marginal coffee growing regions. Moreover, information about locally varying socioeconomic and cultural contexts needs to be strongly considered in order to formulate effective strategies.     

Inclusion of forest harvest legacies, forest type, and regeneration spatial patterns in updated forest maps: A comparison of mapping results

In Maine and other heavily forested states, existing land cover maps quickly become dated due to forest harvesting and land use conversion; therefore, these maps may not adequately reflect landscape properties and patterns relevant to current resource management and ecosystem studies. By updating an older land cover product (the 1993 Maine GAP map) using Landsat imagery and established forest change detection techniques, we demonstrate a practical and accurate means of providing contemporary, spatially explicit forest cover data needed to quantify landscape change. For a 1.8 million hectares study area in northern Maine, we quantify the accuracy of forest harvest classes and compare mapped harvest and regeneration area between the 2004 GAP update product and the 2004 Maine Landcover Dataset (MeLCD), a map recently developed in coordination with the 2001 National Land-Cover Database (NLCD). For the period 1995–2004, the overall harvest/non-harvest accuracy of the GAP update map is 87.5%, compared to 62.1% for the MeLCD. Producer and user accuracy for harvest detection is 92.4% and 89.7%, respectively for the GAP update, and 48.8% and 92.5% for the MeLCD. Mapped harvest area differs considerably, reflecting a systematic under-representation of recent harvest activity on the part of the MeLCD. By integrating older land cover data, the GAP update retains the forest disturbance legacies of the late 1970s through the early 1990s while simultaneously depicting 2004 forest composition for harvested and regenerating stands. In contrast, the MeLCD (and 2001 NLCD) over-represents the area and connectivity of older forest (undisturbed since the late 1970s), and provides no forest composition information for mapped forest regeneration. Systematic misclassification of forest age classes and harvest history has serious implications for studies focused on wildlife habitat modeling, forest inventory, and biomass or carbon stock estimation. We recommend the integration of older land cover data and time-series forest change detection for retention of harvest or disturbance classes when creating new forest and land cover maps.     

国际土地利用与土地覆盖变化对生态环境影响的研究

土地利用与土地覆盖变化作为全球变化的一个重要内容,对全球生态环境产生了巨大的影响,一方面通过影响气候、土壤、水文以及地貌而对自然环境产生了深刻的影响,另一方面则造成了生态系统的生物多样性、物质循环与能量流动以及景观结构的巨大变化,使得生态系统的结构和功能发生了改变。文中介绍了国际上土地利用与土地覆盖变化对生态环境影响的最新研究进展,并对相关研究在未来的发展进行了探讨。     

Assessing the drivers of land use change in the Rumpi hills forest protected area,Cameroon

Protected areas serve two objectives, biodiversity conservation and securing of ecosystem services. But the recent expansion of human activities around Cameroon’s Rumpi Hills Forest Reserve in this Era of Sustainable Development Goals is a call for concern. This study assesses land use and land cover change around the reserve and their potential impact on its sustainability. A total of 250 household surveys were conducted across 13 villages in four selected sites around the reserve in addition to 11 focus group discussions. Landsat 7 ETM (2000) and Landsat 8 OLI (2014) images and topographic maps were utilized to quantify land use and land cover change.

During the 14-year period, dense forest dropped to 90.2% while settlements increased from 744.6 to 2148.8 hectares in 2014. Also, farmlands increased by 18.25% representing a change from 9400.4 to 11117.16 hectares. Over 98% and 85% of the respondents are engaged in the cultivation of food and cash crops and are dependent on the forests for timber and non-timber forests products. Land and tree-based interventions that improve soil fertility should be promoted among smallholder farmers to ensure the sustainability of protected areas in Cameroon.     

Effects of roads,topography, and land use on forest cover dynamics in the Brazilian Atlantic Forest

Roads and topography can determine patterns of land use and distribution of forest cover, particularly in tropical regions. We evaluated how road density, land use, and topography affected forest fragmentation, deforestation and forest regrowth in a Brazilian Atlantic Forest region near the city of São Paulo. We mapped roads and land use/land cover for three years (1962, 1981 and 2000) from historical aerial photographs, and summarized the distribution of roads, land use/land cover and topography within a grid of 94 non-overlapping 100 ha squares. We used generalized least squares regression models for data analysis. Our models showed that forest fragmentation and deforestation depended on topography, land use and road density, whereas forest regrowth depended primarily on land use. However, the relationships between these variables and forest dynamics changed in the two studied periods; land use and slope were the strongest predictors from 1962 to 1981, and past (1962) road density and land use were the strongest predictors for the following period (1981–2000). Roads had the strongest relationship with deforestation and forest fragmentation when the expansions of agriculture and buildings were limited to already deforested areas, and when there was a rapid expansion of development, under influence of São Paulo city. Furthermore, the past (1962) road network was more important than the recent road network (1981) when explaining forest dynamics between 1981 and 2000, suggesting a long-term effect of roads. Roads are permanent scars on the landscape and facilitate deforestation and forest fragmentation due to increased accessibility and land valorization, which control land-use and land-cover dynamics. Topography directly affected deforestation, agriculture and road expansion, mainly between 1962 and 1981. Forest are thus in peril where there are more roads, and long-term conservation strategies should consider ways to mitigate roads as permanent landscape features and drivers facilitators of deforestation and forest fragmentation.     

Changes of forest land use and ecosystem service values along Lao-Chinese border: A case study of Luang Namtha Province, Lao PDR

Forest cover and land use change directly impact biological diversity worldwide, contribute to climate change and affect the ability of biological systems to support human needs by altering ecosystem services. Given the forest land use characteristics and ecosystem types in Luang Namtha Province, Lao PDR, the forest cover and land cover category of Luang Namtha Province were divided into six classes, i.e., current forest (CF), potential forest (PF), other wooded areas (OW), permanent agricultural land (PA), other non-forest areas (NF) and water (W). In first instance, earlier geographic information data (GIS data) of forest cover and land use during 1992 and 2002 was obtained from the Ministry of Agriculture and Forestry (MAF), Lao PDR. Two steps of forest land use change assessment were conducted by the MAF, i.e., plot sampling on satellite image maps (SIMs) to detect the changes of forest cover and land use during 1992 and 2002 for the entire Luang Namtha Province and field verification in order to identify causes of the changes. Secondly, dynamic information of the forest land cover changes during this ten-year period was calculated by means of map algebra in ArcGIS 9.2. Thirdly, based on the theory of ecosystem service functions and the service function values of different global ecosystems, the value of the six forest cover and land use categories in the province was obtained. Finally, ecological environmental effects, produced by the regional land cover changes over the study period, were calculated.     

‘The fridge in the forest’: Historical trajectories of land tenure regulations fostering landscape transformation in Jambi Province,Sumatra, Indonesia

Indonesia has attracted increasing global attention in recent years due to concerns over large-scale deforestation. The island of Sumatra in particular is severely affected by the rapid expansion of monoculture cash crops. Since Dutch colonial times, land tenure regulations here have generally favored such resource exploitation. The current National Development Plan continues to see Sumatra as a center of resource production in order to eradicate poverty and accelerate national development. This developmental focus, however, is accompanied by contested land use scenarios.Taking a historical perspective, this research discloses different layers of past and present land tenure regulations to understand present contestations of land use, resource exploitation, and their social consequences. Based on a village case study, the research demonstrates how different political eras and their accompanying land tenure approaches are inscribed in today's local landscape. We found that de jure regulations which were added to customary laws created a situation of legal pluralism. Our case study explains how local actors craft institutional arrangements in a process of institutional bricolage to use ‘their’ resources.     

Deforestation and loss of bushland and grassland primarily due to expansion of cultivation in mainland Tanzania (1995–2010)

Information on land use and cover changes (LUCC) is important for planning of conservation and development and thus ensure forest sustainability. The current paper assesses LUCC for the whole of the mainland Tanzania. The analyses were done using land use and cover maps covering the whole of mainland Tanzania for 1995 and 2010. For 1995, forest, bushland, grassland, cultivation and other land use and cover (built up areas, bare land, etc.) covered 43.5%, 19.8%, 23.5%, 11.2%, and 2.0% of the study area, respectively. For 2010, the same land use and cover classes covered 38.0%, 14.5%, 6.9%, 36.5%, and 4.1% of the study area, respectively. The annual rate of deforestation was 320,067 ha, which is equivalent to 0.9%. Bushland and grassland were lost at 313,745 and 969,982 ha/year, respectively. Most forest was converted to cultivation and least to other land use and cover. In conclusion, the net changes were deforestation and loss of bushland and grassland primarily due to expansion of cultivation. Further research on how to reduce or halt expansion of cultivation may shed light on improving sustainability of forest, bushland, and grassland in mainland Tanzania.