草地覆盖度变化对生态系统防风固沙服务的影响分析——以内蒙古典型草原区为例

锡林郭勒盟为我国北方典型草原区,草地的退化与恢复影响生态系统的防风固沙服务功能。为了便于制定区域生态恢复的防治措施,实现草地生态系统的可持续发展与防治土壤风蚀危害,本文基于气象、遥感数据,运用RWEQ(Revised Wind Erosion Equation)模型,结合锡林郭勒盟的草地覆盖度变化对20世纪90年代以来的防风固沙服务功能的时空变化趋势进行了定量评估,并分析了草地覆盖度变化对防风固沙服务功能的影响。研究表明:锡林郭勒盟土壤风蚀以微度和轻度侵蚀为主,主要集中在植被盖度较高、降水相对较多,风场强度相对较低的东部、中部和南部地区;中度以上区域主要集中在西部的荒漠草原区与浑善达克沙地区,且侵蚀面积随侵蚀强度的增加而递减;防风固沙服务功能量的分布趋势与土壤风蚀模数的分布趋势基本一致;防风固沙服务功能保有率的分布特征与植被盖度的分布特征基本一致,表现为由西北到东南逐渐增加的趋势;在气候暖干化背景下,受京津风沙源治理工程实施的影响,以微度和轻度侵蚀为主的草地覆盖度减小区转为以微度和轻度为主的覆盖度增加区,轻度和中度以上侵蚀为主的草地覆盖度减小区转为基本持衡区;草地覆盖度的降低与增加对土壤风蚀的加剧和抑制作用明显,大部分地区的防风固沙服务功能保有率的下降(提升)与风蚀季节草地覆盖度的减小与提升呈显著正相关(r0.6,p0.05)。     

自然生态环境遥感动态监测与GIS分析评价——以山西“煤田之乡”的乡宁矿区为例

以1990、2000和2007年三期遥感影像为主体数据源,选取有"煤田之乡"称誉的山西省乡宁县作为实验区,采用遥感与GIS相结合的手段,在建立生态环境评价指标体系的基础上,利用生态环境状况指数(EI),对研究区生态环境进行监测与评价。结果表明:(1)1990-2007年,实验区耕地面积持续减少;林地面积先减少后增加,总体上显著增大;草地面积先增加后减少,总体呈减少趋势;建筑用地面积持续增加;未利用地面积先增加后减少,总体呈减少趋势。(2)1990-2007年,高植被覆盖地区面积先减少后增大,低植被覆盖地区面积持续减少,中度植被覆盖地区面积有所增加。(3)1990-2007年,轻度土壤侵蚀面积先增大后减小,总体面积变化不大;中度侵蚀面积先减小,后显著增大,总体呈增大趋势;重度侵蚀面积先增大,后显著减小,总体呈减小趋势。(4)1990-2000年,实验区生态环境状况明显变差;2000-2007年,生态环境状况显著变好;1990年到2007年生态环境状况略微变好,总体上先明显变差,后显著变好。     

Did Ecological Engineering Projects Have a Significant Effect on Large-scale Vegetation Restoration in Beijing-Tianjin Sand Source Region,China? A Remote Sensing Approach

Aiming for the restoration of degraded ecosystems, many ecological engineering projects have been implemented around the world. This study investigates the ecological engineering project effectiveness on vegetation restoration in the Beijing-Tianjin Sand Source Region(BTSSR) from 2000 to 2010 based on the rain use efficiency(RUE) trend in relation to the land cover. More than half of the BTSSR experienced a vegetation productivity increase from 2000 to 2010, with the increasing intensity being sensitive to the indicators chosen. A clear tendency towards smaller increasing areas was shown when using the net primary productivity(NPP, 51.30%) instead of the accumulated normalized difference vegetation index(59.30%). The short-term variation in the precipitation and intra-seasonal precipitation distribution had a great impact on the remote sensing-based vegetation productivity. However, the residual trends method(RESTREND) effectively eliminated this correlation, while incorporating the variance and skewness of the precipitation distribution increased the models′ ability to explain the vegetation productivity variation. The RUE combined with land cover dynamics was valid for the effectiveness assessment of the ecological engineering projects on vegetation restoration. Particularly, the result based on growing season accumulated normalized difference vegetation index(ΣNDVI) residuals was the most effective, showing that 47.39% of the BTSSR experienced vegetation restoration from 2000 to 2010. The effectiveness of the ecological engineering projects differed for each subarea and was proportional to the strength of ecological engineering. The water erosion region dominated by woodland showed the best restoration, followed by the wind-water erosion crisscross regions, while the wind erosion regions dominated by grassland showed the worst effect. Seriously degraded regions still cover more area in the BTSSR than restored regions. Therefore, more future effort should be put in restoring degraded land.     

六盘水市土壤侵蚀时空特征及影响因素分析

六盘水市是我国生态地位极其重要,水土流失又较为严重的城市。近些年,六盘水市实施了一系列生态工程,为了定量分析六盘水市土壤侵蚀状况及其影响因素,本文基于RUSLE模型,利用降雨数据、遥感影像数据、土地利用数据等,对贵州省六盘水市1990-2015年土壤侵蚀模数和土壤侵蚀量进行定量模拟,分析其时空动态变化,利用地理探测器定量分析影响因素,并进行空间相关性分析,结果表明： ① 六盘水市土壤侵蚀以微度和中度侵蚀为主。土壤侵蚀严重地区主要分布在北盘江流域与南盘江流域交界处以及喀斯特山地地区,煤矿开采使植被覆盖等抑制土壤侵蚀因子减少作用,使局部地区土壤侵蚀程度加剧。② 1990-2010年平均土壤侵蚀模数整体为下降趋势,2010-2015年为上升趋势。其中2000年平均土壤侵蚀模数最大,2010年平均土壤侵蚀模数最小。该变化由降雨可蚀性因子和植被覆盖度因子综合影响所致。③ 植被覆盖度因子和多年平均降雨量因子是影响区域土壤侵蚀空间分布的重要因素。未利用土地、植被覆盖度小于0.3、坡度在25°以上和降雨量在1543~1593 mm之间的地区为高风险侵蚀区域。④ 植被覆盖度与土壤侵蚀在空间上全部呈负相关性,降雨因子与土壤侵蚀在空间上存在负相关性和正相关性。⑤ 土壤侵蚀改善区域大多分布在生态工程区域内,生态工程建设能够改善土壤侵蚀情况,不同生态工程保护侧重点不同导致土壤侵蚀改善程度不同。退耕还林还草工程对六盘水市土壤侵蚀的改善具有重要意义,六盘水市更宜退耕还林。     

Analysis on spatial difference of land use change based on physical and cultural landscape attributes

Land use changes are regarded as landscape pattern change driven by many interactive natural and social-economic factors. Different combination of physical geographical elements induced the difference of spatio-temporal pattern of land use change. There are four physical geographical regions in Mongolian Autonomou County of Qian Gorlos of Jilin Province. Based on spatial analysis and statistical analysis, we conclude that the primary pattern of land use and the tendency of land use changes are all different in four physical geographical regions. During 1987 – 1996, the dominant land use change processes were from grassland or forest to arableland, from unused land to paddy and grassland to unused land. Though land use change is mainly affected by social and economic condition in short period, the composite characters of physical geographical elements controls land use dynamic process. The relationship between land use dynamic process and the character of physical geographical units differ in different regions. Possible human impacts on land use change are explored with application of buffer areas of series distance along main roads and radius around main settlements. A few models are built to describe the relationship between land use spatial change rates and distance to road and settlements. According to our result, the relationship with the proximity to roads was a negative liner function, with the change rate decreasing rapidly when moving away from roads. Within a distance of less 7.5km from main traffic lines, land use changes occur red more. The bulk of grassland was apt to be opened up for cultivation around the settlements and the transformation from dryland to paddy occurred within the distance of 1km away from settlements. Foundation item: Under the auspices of the Knowledge Innovation Project of the Chinese Academy of sciences (KZCXI - Y - 02); the Key Ninth Five-Year Plan (96 - B02 - 01); the National Natural Science Foundation of China (49901017). Biography: HUANG Fang (1971 – ), female, a native of Jilin Province, Ph. D. candidate of Changchun Institute of Geography, the Chinese Academy of Sciences. Her research interests include application of remote sensing and GIS.     

The effects of land uses on purplish soil erosion in hilly area of Sichuan Province,China

1 Introduction Food grain productivity of dry land per capitahas declined significantly during the past fewdecades (Parr et al. 1990). Bowman et al. (1990)and Blaikie (1985) indicated that the greatest lossin productivity comes from soil loss, withsecondary effects from loss of nutrients due toreduced organic matter and increased soil bulkdensity. Soil erosion has major ecological andeconomic consequences in densely populatedChina, particularly, in a large agriculture province,Sichuan…     

Application of matter-element model in soil nutrient evaluation of ecological fragile region

On the basis of the soil environment investigation in Da'an City, Jilin Province, China, 40 soil samples from main land use types were obtained and tested by standard method. Soil organic matter (SOM), total N (TN), total P (TP), total K (TK), available N (AN), available P (AP) and available K (AK) were chosen as the evaluation factors. A regional soil nutrient evaluation model was developed based on the matter-element model. The results show that the soil samples with nutrient grade Ⅱ-Ⅴ respectively account for 10%, 30%, 32.5% and 27.5%, and those with grade Ⅳ and Ⅴ account for 60% in all samples. The relationship between soil nutrients and land types indicates that the nutrients of farmland are relatively good, with 41.7% of soil samples with the nutrient grade Ⅳ and Ⅴ. The nutrients of saline-alkali land and sandy land are the worst, with 100% of soil samples with the nutrient grade Ⅳ and Ⅴ. And the ratios of soil samples grade Ⅳ and Ⅴ in grassland and wasteland are respectively 62.5 % and 54.55%. Generally speaking, the soil nutrients status in Da'an City is poor, 60% of soil samples are in poor and extremely poor conditions, indicating that the soil has been severely eroded. Being a relatively superior evaluation method with more accurate resuits and spatial distribution consistency, matter-element analysis is more suitable for regional soil nutrient evaluation than previous models.     

中国北方典型农牧交错区的土壤风蚀危险度研究

土壤风蚀及其引发的土地退化、沙化和沙尘暴是中国北方严重的环境问题之一。通过定量评估中国北方典型农牧交错地区土壤风蚀危险程度,可以为区域生态环境的保护和生态修复提供科学支撑。本文基于文献调研、兼顾数据的可获得性,建立了包括风场强度、植被覆盖率、地形起伏度、土壤干燥度等因子在内的风蚀危险程度评价指标体系。同时,依据遥感参数反演和地面气象观测数据,在地理信息系统技术支持下,形成了上述因子的空间分布数据。另外,利用层次分析方法,构建土壤风蚀危险度评价模型,得到研究区土壤风蚀危险度的空间分布。最后,结合研究区土地利用数据,探讨了风蚀危险度空间分布格局的自然环境和土地利用背景。研究表明:研究区土壤风蚀极险型区域面积为1.47×10⁴km²,强险型区域面积为6.09×10⁴km²,危险型区域面积为3.47×10⁴km²,轻险型区域面积为3.45×10⁴km²,无险型区域面积为2.19×10⁴km²。本区土壤风蚀危险度呈现出从东南到西北逐渐增强的趋势,这与区域的植被、气候,以及土地利用的空间格局具有内在的有机联系。     

吐鲁番盆地地下水与植被的关系研究

吐鲁番盆地是我国西部极端干旱地区的一个山间盆地,气候干旱、降雨稀少,荒漠生态典型,生态环境脆弱。文章从植被生长与土壤含水率、含盐量、地下水矿化度、埋深等方面进行分析,得出吐鲁番盆地艾丁湖周缘低湿地植被生态可持续发展的合理生态水位为埋深2.5~3.5 m。总结了吐鲁番盆地天然绿洲区的植被随地下水变化的关系及其演替模式。     

知识图谱在构建东北土地环境研究知识谱系中的应用

我国东北地区的自然环境状况一直备受关注,其土地沙化、荒漠化、林地草地退化、森林退化、土地盐碱化等土地环境变化的原因及监测一直是科研的焦点.随着"美丽中国中脊带"的提出,位于该线东北段附近的土地环境相关的研究也不断开展.在涉及该区域土地状况的研究中,常用研究方法有实地考察以及基于遥感卫星影像来进行分析,而本文利用知识图谱...     

微波与光学遥感协同反演旱区地表土壤水分研究

土壤水分是水文循环中的关键因素,尤其对旱区的生态环境具有十分重要的意义。微波遥感是反演土壤水分的有效手段,而植被是影响土壤水分反演精度的重要因素。因此,对土壤水分的反演需要考虑植被的影响。本文以内蒙古乌审旗为研究区,利用Radarsat-2雷达数据与TM光学数据,对旱区稀疏植被覆盖地表土壤水分反演进行研究。利用TM数据,分别选取NDVI和NDWI指数对植被含水量进行反演,通过水云模型消除植被层对土壤后向散射系数的影响;在此基础上,根据研究区地表植被特性,提出一种基于AIEM 模型的反演土壤水分的改进算法,反演了不同粗糙度参数、不同极化（VV极化和HH极化）条件下的研究区土壤水分。反演结果与野外实测数据的对比结果表明,本文提出的基于地表植被特性的土壤水分改进算法,具有更好的适应性;土壤水分反演模式\begin{array}{c}M{v}_{\mathit{\sigma vv}\left(1\right)}^{\mathit{lh}}\end{array}（VV极化方式下采用NDVI去除植被影响的反演模式）更适合于旱区考虑稀疏植被覆盖影响的地表土壤水分的反演。     

银川平原土壤盐渍化与土地利用强度的空间关联分析

银川平原盐渍土时空格局及其与土地利用强度变化关联关系的空间区位特征,可从土地利用强度的角度阐释土壤盐渍化的动因,为盐渍化因地制宜的治理提供参考依据。本文重点研究了盐渍土空间分布定量遥感生成方法,通过土地利用遥感制图、半方差函数的地统计学方法和灰色关联度分析法,对2004-2010 年银川平原的土地利用强度变化、土壤盐渍化程度变化及各类盐渍土与土地利用强度的关联度,进行了空间区位分布特征的可视化表达。研究结果表明:银川平原的发展仍具集聚效应,土地利用强度变化与城镇体系格局、交通干线、沟渠分布、土壤盐分含量密切相关;2004-2010 年间,银川平原土壤盐渍化存在整体减轻、局部加重的空间分布特征,与土地利用强度变化间的响应关系,存在较明显的空间差异;银川平原土壤盐渍化程度变化与土地利用强度变化间的关联度为0.7781,与水体、耕地这2 种土地类型间的关联程度最高。银川平原土壤盐渍化的干扰活动中,水体与耕地类型的利用行为是较重要的影响因子。     

Change of Cultivated Land and Its Implications on Food Security in China

1 Introduction FAO defined food security not only in terms of access to and availability of food, but also in terms of resources distribution to produce food and the purchasing power on food where it is not produced (Shi et al., 1996; Ning, 2004). Obviously, to guarantee everyone adequate food is the primary aim and most important content of food security (Xie et al., 1999). Thus, to increase food supply is a precondition for food security by domestic food production and international food t…     

南方山地丘陵土地利用类型的地形影响GIS分析——以江西省为例

分布广泛的山地丘陵,地形复杂多样,生态环境脆弱,不合理的土地利用方式会造成生态环境的破坏,导致严重的水土流失。分析山地丘陵区土地利用的地形控制机制,对于山地丘陵区土地利用开发与水土保持等生态保护之间权衡提供科学依据而具有重要现实意义。因此,本文以南方山地丘陵分布较广泛的江西省为例,在SRTM数字高程模型(DEM)的支持下,利用中国资源环境数据中心基于Landsat遥感解译的2000年土地利用数据,分析了江西省土地利用结构与高程、坡度和坡向等地形因子的关系。结果表明地形因子是影响江西省土地利用方式的一个重要因素,具体表现在:(1)随着高程和坡度的增加,耕地面积及占土地总面积的比例都呈下降趋势,南坡耕地面积和比例都大于北坡的耕地面积和比例;(2)在低海拔区,林地面积占土地总面积比例随着海拔高程的增加而增加,当海拔高于400米时,基本稳定;(3)居民点和工矿用地受高程和坡度的影响较大,受坡向影响较小;(4)草地的面积随着海拔的增加呈下降趋势,但其面积比随着高程增加呈缓慢增加,受坡度和坡向的影响较小。     

三北工程区植被恢复对土壤风蚀的影响及植被恢复潜力研究

三北地区是我国重要的生态屏障,分析2000—2019年三北防护林体系建设工程（简称：三北工程）区植被恢复时空变化状况,厘定人类活动与气候要素对植被恢复的贡献,探究植被恢复对土壤风蚀影响,评估植被恢复潜力空间,可为三北防护林体系建设工程未来规划管理和科学施策提供参考。本文在选取植被覆盖度和植被净初级生产力表征植被恢复状况基础上,利用地面数据,结合模型模拟,定量评估了2000—2019年三北防护林体系建设工程区植被恢复程度及其对土壤风蚀的影响,并对植被恢复潜力进行探究。研究结果表明：① 2000—2019年植被恢复程度高、较高的面积,占总面积的35.29%和13.16%,主要分布在黄土高原区及北部区域和风沙区与东北华北平原农区的部分地区。人类活动与气候因素对植被恢复贡献率为10.45%和89.55%;② 土壤风蚀以轻度侵蚀和微度侵蚀为主,呈逐年下降趋势,剧烈侵蚀面积减少了66.45%,防风固沙服务得到进一步提升。植被恢复程度与土壤风蚀模数呈负相关关系,植被恢复程度较好有助于降低土壤风蚀模数;③ 三北工程区森林、草地和荒漠生态系统仍有8.16%的恢复潜力,内蒙古高原北部部分地区、哈顺戈壁北部和准噶尔盆地西北部及周边区域、黄土高原南部部分区域存在较大恢复潜力。     

SOIL EROSION AND ITS IMPACTS ON ENVIRONMENT IN YIXING TEA PLANTATION OF JIANGSU PROVINCE

Soil erosion on sloping field has led to a lot of environmental problems. In order to reveal the seriousnessof the damage of soil erosion on sloping fields 137^Cs tracer method was used to estimate soil erosion rate. 137^Cs referenceinventory of 2200Bq/m^2 in Yixing, southern Jiangsu Province, was estimated and a model for estimating erosion of cultivat-od soil was established in order to avoid overestimating soil erosion rates. Then based on the soil erosion rates and mea-sured soil physical and chemical properties, direct and indirect impacts of soil erosion on environment were further dis-cussed. Direct impacts of erosion on environment included on-site and off-site impacts. The on-site impacts were thatsoil layer became thin, soil structure was deteriorated and soil nutrients decreased. The off-site impacts were that waterbodies were polluted. The indirect impacts of soil erosion on environment were the increase of fertilizer application andenergy consumption, and change of adaptability of land uses. Although erosion intensity was not serious in the studyarea, its environmental impacts should not be ignored because of great soil nutrient loss and coazseness of soil particles.     

近30年来中国陆地蒸散量和土壤水分变化特征分析

 对NOAH陆面模式模拟的近30年中国陆地蒸散量和土壤含水量,按照6大片区和5种生态系统类型进行了统计分析。讨论全国以及各大区不同生态系统类型蒸散和土壤含水量的变化,研究不同类型蒸散和土壤含水量的关系。中国陆地蒸散量总体呈增加的趋势,年内蒸散量最大的月份是7月,年末和年初蒸散量较小。而我国中南、西南、华东、东北和西北蒸散量变化趋势和全国的总趋势一致,呈增加的趋势。华北地区蒸散量近30年来总体趋势是下降的,华北蒸散量最大的年份是上世纪90年代。在所有生态系统类型中,林地蒸散最大的有东北、华东、西南和中南4区;而华北和西北草地在各类型中蒸散量所占比例最高。6大片区对比,林地蒸散水量最大的地区是西南和中南,最小的西北;草地蒸散水量最大的地区是西南,最小的是东北区;农田蒸散水量最高的是华东,最低的是西北;荒漠蒸散量最大的片区是西北;湿地蒸散最大的是东北。80年代以来,全国土壤含水量总体呈下降的趋势。从各片区的情况看,仅西北地区稍有增加,其余5区土壤含水量皆是下降的。植被覆盖度和土壤水分是影响蒸散量最重要的因子,在植被覆盖较差时,土壤水分和蒸散量相关性较好。     

Soil erosion control degree of the project of converting farmland to forest in mountainous areas at China��s Southwest border: A case study in Mangshi, Yunnan Province

There have been few in-depth quantitative studies on soil erosion control and the ecological effects of land use changes. Soil erosion is the first eco-environmental problem particularly in mountainous areas. A major problem in the conversion of farmland to forest is to control soil erosion and improve ecological environment and thus to improve land use sustainability. We report results of calculation and analysis on soil erosion from converted farmland parcels in city of Mangshi (near the SW frontier of China) and the surrounding areas before and after the nine-year (2000–2009) project of converting farmland to forest. There was increased water conservation effect, as a result of decreased soil erosion. The average erosion modulus of the farmland returning to eco-friendly uses decreased by 5,535.59 t/km²·a and the control degree of soil erosion modulus reached 71.00%. The increased soil erosion after the returning in the typical sample area “did not drop, but increased” as the terraced fields decreased but sloping farmland increased and yet woodland decreased.     

LAND RECLAMATION PROCESS IN NORTHEAST CHINA SINCE 1900

Landuse/coverchange(LUCC)isafocalthemeandemergingissueinthestudyofglobalenvironmentalchange.Humanmodificationsandalterationstotheenvironmentcauseimpactsonthesurfaceoftheearth,threatenglobalsustainabilityandlivelihoodsystems,andcontributetochangeinthebiogeochemicalcyclesoftheearth,whichinturnaffectatmosphericlevelsofgreenhouseandothertracegases.ConsequentlytheInternationalGeosphere-BiosphereProgram(IGBP)andtheInternationalHumanDimensionsProgram(IHDP)initiatedLUCCProgramtodevelopabette…     

西北地区土壤资源特征及其开发利用与保护

在分析西北地区土壤分布规律的基础上,研究了不同类型区土壤的资源特征及其在开发利用中存在的问题,认为黄土地区土壤土质疏松、粉砂含量高、富含碳酸钙是水土流失的物质基础;干旱区广为分布的荒漠土壤资源的性能低劣、绿洲区水土资源的利用比例失调是造成土地荒漠化、土壤盐渍化的根本原因;而高原土壤的粗骨性、土层浅薄、有效肥力低则加速了草场的退化和沙漠化.提出了西北地区土壤资源的合理利用与生态环境保护相协调的途经,即搞好农田基本建设,采用旱作技术节水和合理用水,扩大林草植被,保护天然草场和林木.并认为西北土壤资源的开发利用要在充分发挥其生产潜力的同时,首先应遵循生态规律,开发与保护并重,防止土壤资源衰竭和破坏.