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1.
Changes of soil labile organic carbon in different land uses in Sanjiang Plain,Heilongjiang Province 总被引：6，自引：2，他引：4
Guilan Zhang 《中国地理科学(英文版)》2010,20(2):139-143
In the Sanjiang Plain,Northeast China,the natural wetland is undergoing a rapid conversion into agricultural land,which has resulted in drastic ecological changes in the region. To investigate the effects of different land uses on soil labile organic carbon,soils of Calamagrostis angustifolia wetland,Carex lasiocarpa wetland,dry farmland,paddy field,forest land and abandoned cultivated land were collected for measuring the contents of soil microbial biomass carbon (MBC),dissolved organic carbon (DOC),readil... 相似文献
2.
A new rainwater harvesting and recycling system for transforming sloping land into terraced farmland
Transforming sloping land into terraced land is an effective approach to cope with the problems including farmland shortage and severe soil erosion.This paper introduces a new system based on rainwater harvesting and recycling technology,which may effectively improve farmland productivity rainwater use efficiency and reduce water and fertilizer inputs.The new system consists of three subsystems：1） A plough layer with the dual function of crop cultivation and rainwater harvesting; 2） A tank below the plough layer for storing water; 3） An irrigation-drainage subsystem.The plough layer and the storage tank,both treated for reducing seepage,are connected through the irrigation and drainage system.Results showed that,compared with the traditional paddy fields,rice evapotranspiration（ and crop coefficient） in the test field remained at a similar level,while the irrigation amount was reduced by 44.3% under the condition of basin irrigation,and the drainage amount decreased by 86.6%,and the non-point source pollution was reduced to 67.7%~87.9%,and the rainwater utilization efficiency increased by 30% and reached 95.4%,and crop yield of middle-season rice reached 9,975 kg/hm2,which was only 0.4% lower than that in the traditional paddy field in the terms of dry matter.The new technology sheds light on new possibilities for transformation of hilly sloping land. 相似文献
3.
贵州省喀斯特地区泥石流灾害易发性评价 总被引：1，自引：0，他引：1
贵州省独特的喀斯特山地环境对地质灾害的孕育有其特有的作用机理。本文初选了10个相关因子进行GIS的方差分析及相关性分析,以筛选喀斯特山区泥石流灾害的主要影响因子及灾害易发性评价。结果表明,研究区内土壤侵蚀因子对泥石流灾害的贡献作用最为显著,断层的影响作用不明显。土壤侵蚀、坡度、坡向、岩石性质、土地利用方式、归一化植被指数（NDVI）、到沟谷的距离及>25 mm日数8个影响因子,具有良好的独立性和代表性,是研究区内泥石流易发性评价的最佳指标;泥石流主要分布在贵州西部云贵高原边境、北部大娄山、东北雾灵山及苗岭等地带,占全省面积的29.51%,贵州中部及东南部泥石流易发程度较低;极高易发区泥石流的分布密度是极低易发区的19倍,其主要的环境特征表现为坡度大、植被覆盖率较低,旱地与工矿用地分布多,土壤侵蚀严重;加强旱地、工矿用地及低植被覆盖区的合理利用及管理,是减少泥石流灾害发生的有效途径。 相似文献
4.
LIU Gangcai ZHANG Jianhui TIAN Guanglong WEI Chaofu College of Resources Environment Southwest Agriculture University Chongqing China Institute of Mountain Hazard Environment Chinese Academy of Science & Water Resources Ministry P. O. Box Chengdu Sichuan China Research Development Department Metropolitan Water Reclamation District of Greater Chicago W. Pershing Road Cicero IL - USA 《山地科学学报》2005,2(1):68-75
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… 相似文献
5.
The stability of soil aggregates and the fractal characteristics of four typical land use types(farmland,grassland,woodland,and bare land) in the Jiangjiagou Ravine(Yunnan,China),a frequent debris flow occurring area,were studied according to the normal mean mass diameter and fractal theory.The present research showed that the stability of the soil aggregates was different for the different land use types.When the soil depth was 0-30 cm,farmland soil formed more aggregates with diameters greater than 0.25 mm,i.e.,the farmland soil was more stable than that of the other three land uses.When the soil depth was 30-45 cm,the order of stability of the soil aggregates was woodland > grassland > farmland > bare land.The fractal dimensions had a significant linear positive correlation with the amount of soil particles with diameters of <0.25 mm,and a significant negative linear correlation with the amount of soil particles with diameters of 0.25-0.5 mm,0.5-1 mm and 1-2 mm.Smaller fractal dimensions of the soil particles correlated with more stable soil aggregates.The fractal dimensions had a positive linear correlation with the soil bulk density and a negative correlation with the concentration of organic matter.These results showed that soil aggregates can be used as a parameter for characterizing the soil structures and properties.According to these results,the soil particle fractal dimensions could not only objectively characterize the stability of the soil structure but also could be used to indicate soil structure and properties.In addition,these results have great significance for the discussion of the comprehensive evaluation of soil. 相似文献
6.
Lili Huo Yuanchun Zou Xianguo Lyu Zhongsheng Zhang Xuehong Wang Yi An 《中国地理科学(英文版)》2018,28(2):325-336
Content and density of soil organic carbon(SOC) and labile and stable SOC fractions in peat mire soil in wetland, soybean field and rice paddy field reclaimed from the wetland around Xingkai Lake in Northeast China were studied. Studies were designed to investigate the impact of reclamation of wetland for soybean and rice farming on stability of SOC. After reclamation, SOC content and density in the top 0–30 cm soil layer decreased, and SOC content and density in soybean field were higher than that in paddy field. Content and density of labile SOC fractions also decreased, and density of labile SOC fractions and their ratios with SOC in soybean field were lower than that observed in paddy field. In the 0–30 cm soil layer, densities of labile SOC fractions, namely, dissolved organic carbon(DOC), microbial biomass carbon(MBC), readily oxidized carbon(ROC) and readily mineralized carbon(RMC), in both soybean field and paddy field were all found to be lower than those in wetland by 34.00% and 13.83%, 51.74% and 35.13%, 62.24% and 59.00%, and 64.24% and 17.86%, respectively. After reclamation, SOC density of micro-aggregates( 0.25 mm) as a stable SOC fraction and its ratio with SOC in 0–5, 5–10, 10–20 and 20–30 cm soil layers increased. SOC density of micro-aggregates in the 0–30 cm soil layer in soybean field was 50.83% higher than that in paddy field. Due to reclamation, SOC density and labile SOC fraction density decreased, but after reclamation, most SOC was stored in a more complex and stable form. Soybean farming is more friendly for sustainable SOC residence in the soils than rice farming. 相似文献
7.
LAND RECLAMATION PROCESS IN NORTHEAST CHINA SINCE 1900 总被引：2，自引：1，他引：1
Landuse/coverchange(LUCC)isafocalthemeandemergingissueinthestudyofglobalenvironmentalchange.Humanmodificationsandalterationstotheenvironmentcauseimpactsonthesurfaceoftheearth,threatenglobalsustainabilityandlivelihoodsystems,andcontributetochangeinthebiogeochemicalcyclesoftheearth,whichinturnaffectatmosphericlevelsofgreenhouseandothertracegases.ConsequentlytheInternationalGeosphere-BiosphereProgram(IGBP)andtheInternationalHumanDimensionsProgram(IHDP)initiatedLUCCProgramtodevelopabette… 相似文献
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临沭县近几年工业发展势头较猛,但土地后备资源不足,经济发展对土地刚性需求大,保护资源与保障发展的双重压力较大。为此,临沭县重视土地利用总体规划,加强土地开发复垦和整理,强化耕地保护意识,加强耕地保护目标责任制,加大执法力度,实现了全县耕地总量的动态平衡。 相似文献
9.
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 总被引：2，自引：0，他引：2
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。 相似文献
10.
STUDY ON THE SPATIAL PATTERNS OF LAND-USE CHANGE AND ANALYSES OF DRIVING FORCES IN NORTHEASTERN CHINA DURING 1990-2000 总被引：4，自引：1，他引：3
Land-use change is an important aspect of global environment change. It is, in a sense, the direct result of human activities
influencing our physical environment. Supported by the dynamic serving system of national resources, including both the environment
database and GIS technology, this paper analyzed the land-use change in northeastern China in the past ten years (1990–2000).
It divides northeastern China into five land-use zones based on the dynamic degree (DD) of land-use: woodland/grassland —
arable land conversion zone, dry land — paddy field conversion zone, urban expansion zone, interlocked zone of farming and
pasturing, and reclamation and abandoned zone. In the past ten years, land-use change of northeastern China can be generalized
as follows: increase of cropland area was obvious, paddy field and dry land increased by 74.9 and 276.0 thousand ha respectively;
urban area expanded rapidly, area of town and rural residence increased by 76.8 thousand ha; area of forest and grassland
decreased sharply with the amount of 1399.0 and 1521.3 thousand ha respectively; area of water body and unused land increased
by 148.4 and 513.9 thousand ha respectively. Besides a comprehensive analysis of the spatial patterns of land use, this paper
also discusses the driving forces in each land-use dynamic zones. The study shows that some key biophysical factors affect
conspicuously the conversion of different land-use types. In this paper, the relationships between land-use conversion and
DEM, accumulated temperature (⩾10°C) and precipitation were analysed and represented. We conclude that the land-use changes
in northeast China resulted from the change of macro social and economic factors and local physical elements. Rapid population
growth and management changes, in some sense, can explain the shaping of woodland/grassland — cropland conversion zone. The
conversion from dry land to paddy field in the dry land — paddy field conversion zone, apart from the physical elements change
promoting the expansion of paddy field, results from two reasons: one is that the implementation of market-economy in China
has given farmers the right to decide what they plant and how they plant their crops, the other factor is originated partially
from the change of dietary habit with the social and economic development. The conversion from paddy field to dry land is
caused prmarily by the shortfall of irrigation water, which in turn is caused by poor water allocation management by local
governments. The shaping of the reclamation and abandoned zone is partially due to the lack of environment protection consciousness
among pioneer settlers. The reason for the conversion from grassland to cropland is the relatively higher profits of farming
than that of pasturing in the interlocked zone of farming and pasturing. In northeastern China, the rapid expansion of built-up
areas results from two factors: the first is its small number of towns; the second comes from the huge potential for expansion
of existing towns and cities. It is noticeable that urban expansion in the northeastern China is characterized by gentle topographic
relief and low population density. Physiognomy, transportation and economy exert great influences on the urban expansion.
Foundation item: Under the auspices of Knowledge Innovation program Key Project of the Chinese Academy of Sciences (KZCX-2-308).
Biography: LIU Ji-yuan (1947 - ), male, a native of Shanghai Municipality, professor, Director General of Institute of Geographical
Sciences and Natural Resources Research, the Chinese Academy of Sciences. His research interests include environment and resources,
remote sensing and geography. 相似文献
11.
Land use changes in Northeast China driven by human activities and climatic variation 总被引：5，自引：0，他引：5
Zongming Wang Zhiming Liu Kaishan Song Bai Zhang Sumei Zhang Dianwei Liu Chunying Ren Fei Yang 《中国地理科学(英文版)》2009,19(3):225-230
Human-induced land use/cover change (LUCC) forms an important component of global environmental change. Therefore, it is important
to study land use/cover and its change at local, regional and global scales. In this paper we conducted the study of land
use change in Northeast China, one of the most important agricultural zones of the nation. From 1986 to 2000, according to
the study results obtained from Landsat images, widespread changes in land use/cover took place in the study area. Grassland,
marsh, water body and woodland decreased by 9864, 3973, 1367 and 10,052km2, respectively. By comparison, paddy field, dry farmland, and built-up land expanded by 7339, 17193 and 700km2, respectively. Those changes bore an interactive relationship with the environment, especially climate change. On the one
hand, climate warming created a potential environment for grassland and marsh to be changed to farmland as more crops could
thrive in the warmer climate, and for dry farmland to paddy field. On the other hand, the changed surface cover modified the
local climate. Those changes, in turn, have adversely influenced the local environment by accelerating land degradation. In
terms of socio-economic driving forces, population augment, regional economic development, and national and provincial policies
were confirmed as main driving factors for land use change.
Foundation item: Under the auspices of the Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-341),
National Natural Science Foundation of China (No. 40871187, 40801208) 相似文献
12.
This paper tries to qualitatively analyze land use and cover changes (LUCC) and accompanied soil degradation in China, the data of World Atlas of Agriculture in 1969, Land Cover Data of Asia in 1992 and Global Assessment of Human Induced Soil Degradation in 1992, etc. have been used. From 1960' s to 1990's, the area of forestland had increased, arable land and paddy as well as grassland had significantly decreased in China. The major type of soil degradation is due to water erosion, which is widely distributed especially in Loess Plateau and in Southeast and Southwest China, this happened in forestland, grassland and arable land and mainly resulted from deforestation. The secondary type is wind erosion, which is mainly distributed in Northwest China, it happened in arable land and grassland and was caused by overgrazing. Chemical deterioration is distributed in North and Northwest China, which happened in paddy, arable land and grassland. Physical deterioration only concentrated in local area in North China, it happened in arable and paddy. Chemical and physical deteriora-tion mainly resulted from unreasonable activity. Because of different human activities, different LUCC and different natural conditions, the types and strength of soil degradation can be different. 相似文献
13.
JIANG Qigang 《东北亚地学研究》2002,(1)
This paper tries to qualitatively analyze land use and cover changes (LUCC) and accompanied soil degradation in China, the data of World Atlas of Agriculture in 1969, Land Cover Data of Asia in 1992 and Global Assessment of Human Induced Soil Degradation in 1992, etc. have been used. From 1960' s to 1990's, the area of forestland had increased, ara-ble land and paddy as well as grassland had significantly decreased in China. The major type of soil degradation is due to wa-ter erosion, which is widely distributed especially in Loess Plateau and in Southeast and Southwest China, this happened in forestland, grassland and arable land and mainly resulted from deforestation. The secondary type is wind erosion, which is mainly distributed in Northwest China, it happened in arable land and grassland and was caused by overgrazing. Chemical deterioration is distributed in North and Northwest China, which happened in paddy, arable land and grassland. Physical de-terioration only concentrated in local area in North 相似文献
14.
To evaluate the influence of wetland reclamation on vertical distribution of carbon and nitrogen in coastal wetland soils, we measured the soil organic carbon(SOC), soil total nitrogen(STN) and selected soil properties at five sampling plots(reed marsh, paddy field, corn field, forest land and oil-polluted wetland) in the Liaohe River estuary in September 2013. The results showed that reclamation significantly changed the contents of SOC and STN in the Liaohe River estuary(P 0.001). The SOC concentrations were in the order: oil-polluted wetland corn field paddy field forest land reed marsh, with mean values of 52.17, 13.14, 11.46, 6.44 and 6.16 g/kg, respectively. STN followed a similar order as SOC, with mean values of 1351.14, 741.04, 632.32, 496.17 and 390.90 mg/kg, respectively. Interaction of reclamation types and soil depth had significant effects on SOC and STN, while soil depth had significant effects on SOC, but not on STN. The contents of SOC and STN were negatively correlated with pH and redox potential(Eh) in reed marsh and corn field, while the SOC and STN in paddy field had positive correlations with electrical conductivity(EC). Dissolved organic carbon(DOC), ammonium nitrogen(NH_4~+-N) and nitrate nitrogen(NO_3~–-N) were also significantly changed by human activities. NH_4~+-N and NO_3~–-N increased to different degrees, and forest land had the highest NO_3~–-N concentration and lowest DOC concentration, which could have been caused by differences in soil aeration and fertilization. Overall, the results indicate that reed harvest increased soil carbon and nitrogen release in the Liaohe River Estuary, while oil pollution significantly increased the SOC and STN; however, these cannot be used as indicators of soil fertility and quality because of the serious oil pollution. 相似文献
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围填海是沿海地区解决土地资源短缺的重要手段,及时准确地监测地区围填海时空动态变化对于合理保护海岸带资源和推进地区社会经济可持续发展具有重要意义。本文基于遥感、GIS技术,结合多种数据源,提取并分析1974-2017年山东省大陆海岸围填海时空动态变化特征。结果表明,43年来山东省大陆海岸围填海面积持续增长,到2017年总面积达到4649.26 km 2,围海为主要利用方式。围海活动多分布于黄河三角洲及莱州湾滩涂海域,填海活动则集中分布于沿海各大港口海域和城市滨海区域。全省围填海呈现出明显的阶段性特征,特别是2000年后,填海造地面积增加迅速,围海利用向填海造地转换现象突出,主要用于港口及临港产业发展和城镇与旅游基础设施建设,受沿海地区发展战略和城镇化、工业化驱动明显,围填海利用向综合化、多元化和集中集约化发展。 相似文献
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ＴＨＥ ＣＯＲＲＥＳＰＯＮＤＩＮＧ ＡＮＡＬＹＳＩＳ ＯＦ ＨＥＡＶＹ－ＭＥＴＡＬ ＰＯＬＬＵＴＩＯＮ ＯＦ ＳＯＩＬ ＩＮ ＺＨＵＺＨＯＵ ＣＩＴＹ ＳｈａｎｇＪｉｎｃｈｅｎｇ（尚金城）；ＬｏｎｇＡｉｍｉｎ（龙爱民）ＬｉＢｉｎ（李斌）；ＪｉａｎｇＪ... 相似文献
20.
黄土高原生态退耕的时空分异特征 总被引：1，自引：0，他引：1
生态退耕是调整陆地生态系统结构与功能以应对土地利用过度干扰的重要途径之一,因此科学掌握退耕格局与耕地格局演变对黄土高原生态环境治理与生态修复具有深远意义。本文以位于黄土高原的延安市为典型区,从生态退耕的整体特征、地形因素及区域差异等角度,探究生态退耕以来其耕地变化及退耕状况的空间分异特征。结果表明：生态退耕致使延安市耕地面积由2000年的11 752.80 km2减少为2013年的9149.93 km2,退耕面积为2756.85 km2,退耕指数为22.15%,且退耕耕地主要转化为林地、草地,占退耕面积的95.29%;耕地与退耕面积主要分布于6~15°、15~25°坡度及第II级（925~1115 m）、第III级（1115~1275 m）,且2005-2013年的生态退耕速率均高于2000-2005年的生态退耕速率;县域退耕面积及退耕程度均呈现由北向南依次递减的分异特征,而退耕重心与耕地重心均在延安市几何中心以北的安塞县与宝塔区边界,且生态退耕的重心由东北向西南方向迁移,耕地重心则由北向南迁移。本文通过对延安市生态退耕的时空分异特征分析可为黄土高原更加科学合理地推进生态保育与生态文明建设提供参考。 相似文献