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A method for determining vegetation growth process using remote sensing data: A case study in the Three-River headwaters Region, China

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Journal of Mountain Science 2019年第9期16卷 2001-2014页

作者： CHEN Tian-tian YI Gui-hua ZHANG Ting-bin WANG Qiang BIE Xiao-juan Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China University of Chinese Academy of Sciences Beijing 100049 China School of Geography and Tourism Chongqing Normal University Chongqing 401331 China College of Management Science Chengdu University of Technology Chengdu 610059 China College of Earth Science Chengdu University of Technology Chengdu 610059 China Chongqing Institute of Surveying and Planning for Land Resources and Housing Chongqing 400020 China

Accurate measurements of the associated vegetation phenological dynamics are crucial for understanding the relationship between climate change and terrestrial ecosystems. However, at present, most vegetation phenological calculations are based on a single algorithm or method. Because of the spatial, temporal, and ecological complexity of the vegetation growth processes, a single algorithm or method for monitoring all these processes has been indicated to be elusive. Therefore, in this study, from the perspective of plant growth characteristics, we established a method to remotely determine the start of the growth season(SOG) and the end of the growth season(EOG), in which the maximum relative change rate of the normalized difference vegetation index(NDVI) corresponds to the SOG, and the next minimum absolute change rate of the NDVI corresponds to the EOG. Taking the Three-River headwaters Region in 2000–2013 as an example, we ascertained the spatiotemporal and vertical characteristics of its vegetation phenological changes. Then, in contrast to the actual air temperature data, observed data and other related studies, we found that the SOG and EOG calculated by the proposed method is closer to the time corresponding to the air temperature, and the trends of the SOG and EOG calculated by the proposed method are in good agreement with other relevant studies. Meantime, the error of the SOG between the calculated and observed in this study is smaller than that in other studies.

关键词： Vegetation phenology Normalized difference vegetation index (NDVI) Start of the growth season (SOG) End of the growth season (EOG) Three-River headwaters Region(TRHR)

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Postglacial incision-infill cycles at the Borisoglebsk Upland: Correlations between interfluve headwaters and fluvial network

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International Soil and Water Conservation Research 2019年第2期7卷 184-195页

作者： Yuliya V.Shishkina Ekaterina V.Garankina Vladimir R.Belyaev Ilya G.Shorkunov Pavel V.Andreev Aleksey I.Bondar Viktoria I.Potapova Tatiana A.Verlova Faculty of Geography Department of Geomorphology and Palaeogeography and Laboratory for Soil Erosion and Fluvial ProcessesLomonosov Moscow State UniversityLeninskie Gory1Moscow 119991Russia Institute of Geography Department of Soil Geography and EvolutionRussian Academy of SciencesStaromonetnyj Lane29Moscow 119017Russia Institute of Earth Sciences of Saint-Petersburg State University St.PetersburgUniversitetskaya nab.7-9 199034Russia

The article discusses postglacial landscape transformation in the Northern Hemisphere Middle Pleistocene glaciation area located in the center of the Russian *** attempted to verify the regional paleogeographic model by reconstructing the Late Pleistocene incision-infill cycles at the Eastern Borisoglebsk Upland based on a comparison of inactive interfluves headwaters and actual fluvial network *** study was also aimed to determine the past extent of fluvial *** research of the actual and buried topography,Ethology and pedogenic properties of surface deposits was carrid out with remote sensing data interpretation,DGPS survey,and detailed description of geological cores *** study was followed by analysis of grain size,chemical and organic contents,microstructure,and numerical *** the available results,we propose a scenario of the fluvial network transformation at the Eastem Borisoglebsk Upland over the last 150 *** least four fluvial incision stages were determined while network extent has significantly changed through the Late *** can be generally associated with the regional base level decrease-Late Moscow,Late Valdai and Late Holocene and accompanying isolation of the Nero Lake terraces of 130 m,100-105 m and 95-98 *** stages were separated by landscape stability or aggradation periods those were asynchronous at the middle and upper parts of the fluvial *** main agent of initial valley infill appears to be local lacustrine sedimentation altered by alluvial and colluvial deposition towards the second half of *** landscape conditions variability emphasize the importance of comprehensive local correlations for regional retrospective models.

关键词： Interfluve headwaters Fluvial Incision-Infill Cycle Pleistocene

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The Recovery of Two Long-logged headwaters in Temengor Reservoir,Perak,Malaysia

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湿地科学 2011年第2期9卷 140-150页

作者： Zarul Hazrin Hashim Amir Shah Ruddin Md Shah Khoo Khay Huat Shahrul Anuar Md.Sah Mashhor Mansor School of Biological Sciences Universiti Sains Malaysia11800 USM Pulau PinangMalaysia

A study on water quality of the two long-logged and abandoned headwaters in Temengor Reservoir was conducted to determine their natural *** this study,we used National Water Quality Standards for Malaysia prepared by Malaysian Department of Environment as an indicator for water quality *** parameters measured were dissolved oxygen（mg/L）,water temperature（℃）,pH,conductivity（mS/cm）,total dissolved solids（mg/ L）,water velocity（m/s）,ortho-phosphate（PO4-P）,nitrite-nitrogen（NO2-N）,nitrate-nitrogen（NO3,-N）and alkalinity. In general,water quality in Sungai Enam and Sungai Telang were in ClassⅠ,indicating water quality in both streams have *** on the t-test,Sungai Enam and Sungai Telang differed significantly in all parameters except for dissolved oxygen,NO2-N and *** spatial analyses（upper,middle and lower reaches comparisons）, the two-way ANOVA analysis shows that there were significant differences in all studied parameters between the two rivers except for dissolved oxygen,total dissolved solids,NO2-N and *** flow,hydrologic pathways,geomorphology,physical and environmental characteristics are essential elements in understanding the dynamics of water systems in Sungai Enam and Sungai *** to the recovery,these two headwaters are thus suitable for fish conservation and restoration sites.

关键词： water quality Temengor Reservoir hydrology nutrient headwaters

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headwaters Deforestation for Cattle Pastures in the Andes of Colombia and Its Implications for Soils Properties and Hydrological Dynamic

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Open Journal of Forestry 2016年第5期6卷 337-347页

作者： Guillermo Vásquez-Velásquez Forest Science Department National University of Colombia Medellín Colombia

Deforestation of headwater in the Andes of Colombia is a historical process that has its origins in pre-Hispanic communities and in nineteenth and twentieth centuries, intensified by settlers and farmers. These lands have been intended mainly to pasture cattle. Soil compaction, caused by the trampling of cattle, was evaluated in soils derived from volcanic ash (Andisols), with reference to values found for variables in undisturbed natural forests in the same region. The compared parameters were bulk density (Db), total porosity (α), soil resistance to penetration (Rp) and pore size distribution, analyzed by water retention curves (WRC). The grazed soils had significant differences with respect to the natural forest reference values: Db was 53.7% higher, α was reduced by 11.0% and Rp in the first 7.5 cm of the top soil was more than double, with an average increase of 275.2 to 527.2 kPa. The analysis indicated that compacted soils had relatively uniform reduction in distribution of macro, meso and micropores. It was concluded that deforestation followed by pasture land destination in steep headwaters generates significant compaction processes that can affect the infiltration, percolation and soil water storage, which would have important hydrological implications: augmentation of surface runoff and soil erosion, decreased the base flow and increased direct runoff. For this reasons, it is considered that forest restoration of headwaters is important for the maintenance of hydrological functions of large river systems.

关键词： Forest Influences Deforestation Soil Compaction headwaters

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Long-term ecological compensation policies and practices in China:Insights from the Three Rivers headwaters Area

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Ecological Economy 2015年第2期8卷 175-184页

作者： LI Fen ZHANG Lin-bo LI Dai-qing GONG Bin ZHU Fu-jing Chinese Research Academy of Environmental Sciences State Environmental Protection Key Laboratory of Regional Ecological Processes and Functions Assessment State Key Laboratory of Environmental Criteria and Risk Assessment Jiangxi Province Key Lab for Digital Land East China Institute of Technology

Using the Three Rivers headwaters Area in China as a pilot project, this study has investigated the effectiveness of the ecological compensation policies and practices have implemented in this area over the past decade. Major issues have encountered during the implementation process, including the formidable extent of grassland degradation, the comprehensive nature of measures needed to restore the ecosystem, and the time needed to achieve these goals. These issues are discussed, and remedial measures proposed. They include: drafting regulations giving the Three Rivers headwaters Area ecological protection, setting aside funds for ecological compensation and establishing a national park, using an ecological assets accounting methodology for financial reporting purposes, designing a science-based approach for conducting the livestock husbandry population migration, enhancing the oversight capacity for all aspects of the ecological compensation process, and making an overall plan to promote the harmonious development of this area together with other regions in Qinghai Province.

关键词： ecological compensation ecological assets accounting national park supervise Three Rivers headwaters Area

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The significance of small streams

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Frontiers of Earth Science 2017年第3期11卷 447-456页

作者： Ellen WOHL Department of Geosciences Colorado State University Fort Collins CO 80523-1482 USA

headwaters, defined here as first- and second- order streams, make up 70%-80% of the total channel length of river networks. These small streams exert a critical influence on downstream portions of the river network by： retaining or transmitting sediment and nutrients; providing habitat and refuge for diverse aquatic and riparian organisms; creating migration corridors; and governing connectivity at the watershed-scale. The upstream-most extent of the channel network and the longitudinal continuity and lateral extent of headwaters can be difficult to delineate, however, and people are less likely to recognize the importance of headwaters relative to other portions of a river network. Consequently, headwaters commonly lack the legal protections accorded to other portions of a river network and are more likely to be significantly altered or completely obliterated by land use.

关键词： headwaters hydrology water quality landuse connectivity resilience

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Effects of Broussonetia papyrifera invasion and land use on vegetation characteristics in a tropical forest of Ghana

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Journal of Forestry Research 2019年第4期30卷 1363-1373页

作者： David M.Adigbli Alexander K.Anning James K.Adomako Benedicta Y.Fosu-Mensah Institute for Environment and Sanitation Studies University of GhanaLegonAccraGhana Department of Theoretical and Applied Biology Kwame Nkrumah University of Science and TechnologyKumasiGhana Department of Botany University of GhanaLegonAccraGhana

The purpose of this study was to evaluate the effects of Broussonetia papyrifera(paper mulberry)invasion and land use on the floristic composition of a dry semideciduous forest in ***-five plots(25 m×25 m each),distributed among three land uses-selectively logged(SL);abandoned farmlands(AF);and an undisturbed reference(RF)-were *** showed lower tree species richness(S),diversity(H’),evenness(S)and basal area(BA)in the SL(46,0.78,0.32 and 269.12 m2 ha-1,respectively)and AF(40,0.53,0.45,and 131.16 m^2 ha^-1)sites compared to the RF site(79,2.66,0.87,963.72 m^2 ha^-1).Similar patterns were found at the shrub layer,but no differences were observed at the herb ***-metric multidimensional scaling ordination revealed distinct species composition among the land *** two disturbed habitats,SL and AF,were associated with increased *** invasion particularly in the overstory,with importance value index and mean relative density of 45 and 65.03%,and 42 and 53.29%,***,the species was only sparsely represented in the RF *** density of *** correlated negatively with H’,S,E,BA,and native tree density and *** findings highlight the strong link between human land use(i.e.,logging and slash-andburn farming),invasion,and vegetation characteristics,and suggest the need to limit these disturbances to conserve biodiversity within tropical forest ecosystems.

关键词： Afram headwaters Forest Reserve Broussonetia papyrifera Forest community characteristics Human-caused disturbances Plant invasion

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Using ground penetrating radar to assess the variability of snow water equivalent and melt in a mixed canopy forest, Northern Colorado

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Frontiers of Earth Science 2017年第3期11卷 482-495页

作者： Ryan W. WEBB Institute of Arctic and Alpine Research University of Colorado Boulder Boulder CO 80309-0450 USA

Snow is an important environmental variable in headwater systems that controls hydrological processes such as streamflow, groundwater recharge, and evapotran- spiration. These processes will be affected by both the amount of snow available for melt and the rate at which it melts. Snow water equivalent （SWE） and snowmelt are known to vary within complex subalpine terrain due to terrain and canopy influences. This study assesses this variability during the melt season using ground penetrating radar to survey multiple plots in northwestern Colorado near a snow telemetry （SNOTEL） station. The plots include south aspect and flat aspect slopes with open, coniferous （subalpine fir, Abies lasiocarpa and engelman spruce, Picea engelmanii）, and deciduous （aspen, popu- lous tremuooides） canopy cover. Results show the high variability for both SWE and loss of SWE during spring snowmelt in 2014. The coefficient of variation for SWE tended to increase with time during snowmelt whereas loss of SWE remained similar. Correlation lengths for SWE were between two and five meters with melt having correlation lengths between two and four meters. The SNOTEL station regularly measured higher SWE values relative to the survey plots but was able to reasonably capture the overall mean loss of SWE during melt. Ground Penetrating Radar methods can improve future investiga- tions with the advantage of non-destructive sampling and the ability to estimate depth, density, and SWE.

关键词： headwaters snowmelt snow water equiva-lent ground penetrating rdar SNOTEL

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Effects of mountain pine beetle-killed forests on source water contributions to streamflow in headwater streams of the Colorado Rocky Mountains

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Frontiers of Earth Science 2017年第3期11卷 496-504页

作者： Christine E. WEHNER John D. STEDNICK Watershed Science Program College of Natural Resources Colorado State University Fort Collins CO 80523-1472 USA

Natural or human-influenced disturbances are important to the health and diversity of forests, which in turn, are important to the water quantity and quality exported from a catchment. However, human-induced disturbances （prescribed fire and harvesting） have been decreasing, and natural disturbances （fires and insects） have been increasing in frequency and severity. One such natural disturbance is the mountain pine beetle （MPB）, （Denclroctonus ponderosae） an endemic species. A recent epidemic resulted in the mortality of millions of hectares of lodgepole pine （Pinus contorta） forests in Colorado, USA. Beetle-induced tree mortality brings about changes to the hydrologic cycle, including decreased transpiration and interception with the loss of canopy cover. This study examined the effect of the mountain pine beetle kill on source water contributions to streamflow in snowmelt- dominated headwater catchments using stable isotopes （2H and ~80） as tracers. Study catchments with varying level of beetle-killed forest area （6% to 97%） were sampled for groundwater, surface water, and precipitation. Streams were sampled to assess whether beetle-killed forests have altered source water contributions to streamflow. Ground- water contributions increased with increasing beetle-killed forest area （p = 0.008）. Both rain and snow contributions were negatively correlated with beetle-killed forest area （p = 0.035 and p = 0.011, respectively）. As the beetle-killed forest area increases, so does fractional groundwater contribution to streamflow.

关键词： mountain pine beetle isotope tracers stream-flow generation headwaters

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Headwater regions- Physical, ecological, and social approaches to understand these areas： introduction to the special issue

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Frontiers of Earth Science 2017年第3期11卷 443-446页

作者： Steven R. FASSNACHT Ryan W. WEBB William E. SANFORD ESS-Watershed Science Colorado State University Fort Collins CO 80523-1476 USA Geographisches Institut Abt. Kartographie GIS & Femerkundung Georg-August-Universitat Gottingen 37077 Gottingen Germany Cooperative Institute for Research in the Atmosphere Fort Collins CO 80523-1375 USA Geospatial Centroid Colorado State University Fort Collins CO 80523-1101 USA Natural Resources Ecology Laboratory Fort Collins CO 80523-1499 USA Institute of Arctic and Alpine Research University of Colorado Boulder Boulder CO 80309-0450 USA Geosciences Colorado State University Fort Collins CO 80523-1482 USA

Around the world human communities and natural ecosystems both rely on headwater regions for vital resources. Resources provided include groundwater sto- rage （Flint et al., 2008; Clilverd et al., 2011; Cao et al., 2012） in addition to soil moisture and forest ecosystem dynamics （McNamara et al., 2005; Williams et al., 2009; Jencso and McGlynn, 2011; Smith et al., 2011; Harpold et al., 2015; Webb et al., 2015）. Furthermore these regions are ecologically vital zones （Schlosser, 1995; Lowe and Likens, 2005） that impact downstream water quality （Peterson et al., 2001; Alexander et al., 2007）.

关键词： Social behavior headwaters

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