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1.
This paper interprets a stone‐banked lobe on the upper western face of Mt Rufus, at an altitude of 1380 m in western Tasmania, Australia. The morphology of the deposit resembles that of a solifluction lobe. Field observations show vertical and downslope movement of pebbles, cobbles and small boulders over a single winter season. The movement is largely related to frost pull (10–15 cm) and shallow freeze–thaw processes promoting the downslope (up to 50 cm yr–1) creep of material and the accumulation of coarse clasts at the lobe riser. The climate of Mt Rufus is strongly maritime and this is reflected in the limited duration and depth of penetration of frozen ground at this site during the 2013 winter. Despite the relatively mild climatic conditions, freeze–thaw processes are clearly the dominant geomorphic force operating at the site. These findings support observations of active stone‐banked lobes on sub‐Antarctic islands where intense freezing is absent. Both there and at Mt Rufus, movement is dominated by freeze–thaw processes operating in the upper c. 20 cm of the regolith. These are typical landforms of marginal freeze–thaw settings.  相似文献   

2.
Abstract

Erosion rates in residual limestone soils in a humid climate were measured for 10 years at one site, and for 4 years at another site, using erosion pins. Erosion pins were placed in gully floors and on convex divides between adjacent gullies, on abandoned land where vegetation had been removed. We measured an average erosion rate of 20 mm yr?1 over 10 years at one site and only 5 mm yr?1 over 4 years at another site where chert gravel was common on the surface. The 10-year average erosion rate of divides (26 mm yr?1) was significantly greater than the average erosion rate of gullies (14 mm yr?1), suggesting control by different processes, some of which may be seasonal. In winter, it was observed that frost action produced a thin layer of loose soil on the surface of divides. In summer, a hardpan developed on divides, as the soil loosened by winter frosts was transported to gullies, likely by rainsplash or dry ravel. The diffusive processes of frost action, rainsplash, and dry ravel appear to shape the convex divides in this study. Down-cutting of gullies requires channelized flow produced by intense rainfall, which is more common in summer for this location.  相似文献   

3.
Surface velocities have been regularly monitored at the rock glacier in Outer Hochebenkar, Ötztal Alps, Austria since the early 1950s. This study provides an update to previously published surface velocity time series, showing mean profile velocities of four cross profiles since the beginning of the measurements (1951,1954, 1997; depending on the profile), as well as single block displacements from 1998 to 2015. Profiles P1, P2 and P3 have moved between 42 and 90 m, at mean velocities between 0.70 and 1.48 m yr–1, since they were first established in the early 1950s (1951/54). Profile P0, established in 1997, has since moved 13 m or 0.75 m yr–1. An acceleration can be observed at all profiles since the late 1990s, with a particularly sharp velocity increase since 2010. All profiles reached a new maximum velocity in 2015, with 1.98 m yr–1 at the slowest profile (P0) and 6.37 m yr–1 at the fastest profile (P1). Year‐to‐year variations in profile velocities cannot be clearly attributed to inter‐annual variations of climatic parameters like mean annual air temperature, summer temperature, positive degree days, or precipitation. However, higher correlation is found between velocities and cumulative anomalies of air temperature (mean annual air temperature and positive degree days) and summer precipitation, suggesting that these parameters play a key role for the movement of the rock glacier. The lower profiles (P0, P1) show more pronounced year‐to‐year variations than the upper profiles (P2, P3). It is considered likely that processes other than climatic forcing (e.g. sliding, topography) contribute to the different velocity patterns at the four profiles.  相似文献   

4.
The well‐constrained seismic stratigraphy of the offshore Canterbury basin provides the opportunity to investigate long‐term changes in sediment supply related to the formation of a transpressive plate boundary (Alpine Fault). Reconstructions of the relative motion of the Australian and Pacific plates reveal divergence in the central Southern Alps prior to ～20.1 Ma (chron 6o), followed by increasing average rates of convergence, with a marked increase after ～6 Ma (late Miocene). A strike–slip component existed prior to 33.5 Ma (chron 13o) and perhaps as early as Eocene (45 Ma). However, rapid strike–slip motion (>30 mm yr?1) began at ～20.1 Ma (chron 6o). Since ～20.1 Ma there has been no significant change in the strike–slip component of relative plate motion. Sedimentation rates are calculated from individual sequence volumes that are then summed to represent sequence groups covering the same time periods as the tectonic reconstructions. Rates are relatively high (>22 mm yr?1), from 15 to ～11.5 Ma (sequence group 1). Rates decrease to a minimum (<15 mm yr?1) during the ～11.5–6 Ma interval (sequence group 2), followed by increased rates during the periods of ～6–2.6 Ma (21 mm yr?1; group 3) and 2.6–0 Ma (～25 mm yr?1; group 4). Good agreement between sedimentation and tectonic convergence rates in sequence groups 2–4 indicates that tectonism has been the dominant control on sediment supply to the Canterbury basin since ～11.5 Ma. In particular, high sedimentation rates of 21 and ～25 mm yr?1 in groups 3 and 4, respectively, may reflect increased plate convergence and uplift at the Southern Alps at ～6 Ma. The early‐middle Miocene (～15–11.5 Ma) high sedimentation rate (22 mm yr?1) correlates with low convergence rates (～2 mm yr?1) and is mainly a response to global climatic and eustatic forcing.  相似文献   

5.
Kinematics of a landslide derived from archival photogrammetry and GPS data   总被引：3，自引：0，他引：3  
P. Baldi  N. Cenni  M. Fabris  A. Zanutta   《Geomorphology》2008,102(3-4):435-444
The evolution of the Patigno landslide, a deep-seated gravitational slope deformation in the Northern Apennine range (Italy), was investigated using archival photogrammetry, and GPS observations from a permanent station located inside the landslide. Historical aerial photographs of the area taken in 1975 (scale 1:13,000), 1987 (1:13,000) and 2004 (1:30,000) were co-registered into the same reference frame using an unconventional method based on the detection of homologous points in multi-temporal models. Three DTMs were produced using a Digital Photogrammetric Workstation and compared. The displacement vectors of 293 points in the landslide were determined. The average movement velocity of the GPS station since 2004 (about 3.5 cm yr− 1) agrees with the mean displacement rate obtained from photogrammetry. Furthermore, the estimated velocity varies seasonally between 3 and 6 cm yr− 1. This variability correlated with rainfall suggests that the creep of the landslide is influenced by hydrological factors.  相似文献   

6.
Tectonically active coastal regions of the world recently have been suggested to supply the bulk of sediment from land to the oceans. Seabed sampling on the continental shelf and in coastal embayments of the north-east Gulf of Alaska (Alsek River to Prince William Sound) was performed to examine the temporal and spatial variability of sediment accumulation in a mountainous coastal setting. Cores of varying lengths (30–300 cm) were collected at 84 stations to provide information on sedimentary processes using radiochemical (210Pb and 137Cs) techniques. Four types of 210Pb activity profiles were observed, dominantly reflecting steady-state sediment accumulation. However, nonsteady-state profiles also were measured, resulting in part from episodic deposition near glacier-fed rivers and on the Copper River Delta. Sediment accumulation rates in the eastern half of the study area are highest at midshelf depths (≈100 m) (≥10 mm yr?1) and near rivers draining the Bering Glacier (≈20 mm yr?1). On the Copper River Delta, sediment accumulation rates are highest for the delta front (> 20 mm yr?1) and decrease westward along the sediment dispersal route. Total annual sediment accumulation is 90–140×106 tons yr?1 on the shelf in the study area. Annual sediment accumulation for the total marine environment in the study area (including Icy and Yakutat Bays) exceeds 250×106 tons yr?1, potentially making this region the largest sink for sediment in North America. Spatial patterns in sediment accumulation on the shelf are similar between centennial and Holocene time-scales, reflecting the dominance of the Copper River and Bering and Malaspina glaciers as sediment sources. Temporal variability in accumulation rates between centennial and Holocene time-scales exists for portions of the study area near fiords and demonstrates the considerable changes that occur in sediment supply during glacial advances and retreats.  相似文献   

7.
Topographic change in regions of active deformation is a function of rates of uplift and denudation. The rate of topographic development and change of an actively uplifting mountain range, the Santa Monica Mountains, southern California, was assessed using landscape attributes of the present topography, uplift rates and denudation rates. Landscape features were characterized through analysis of a digital elevation model (DEM). Uplift rates at time scales ranging from 104 to 106 years were constrained with geological cross-sections and published estimates. Denudation rate was determined from sediment yield data from debris basins in southern California and from the relief of rivers set into geomorphic surfaces of known age. First-order morphology of the Santa Monica Mountains is set by large-scale along-strike variations in structural geometry. Drainage spacing, drainage geometry and to a lesser extent relief are controlled by bedrock strength. Dissection of the range flanks and position of the principal drainage divide are modulated by structural asymmetry and differences in structural relief across the range. Topographic and catchment-scale relief are ≈300–900 m. Mean denudation rate derived from the sediment yield data and river incision is 0.5±0.3 mm yr?1. Uplift rate across the south flank of the range is ≈0.5±0.4 mm yr?1 and across the north flank is 0.24±0.12 mm yr?1. At least 1.6–2.7 Myr is required to create either the present topographic or the catchment-scale relief based on either the mean rates of denudation or uplift. Although the landscape has had sufficient time to achieve a steady-state form, comparison of the time-scale of uplift and denudation rate variation with probable landscape response times implies the present topography does not represent the steady-state form.  相似文献   

8.
The Upper Mississippian (ca. 325 Ma) Pride Shale and Glady Fork Member in the Central Appalachian Basin comprise an upward‐coarsening, ca. 60‐m‐thick succession of prodeltaic‐delta front, interlaminated fine‐grained sandstones and mudstones gradational upwards into mouth‐bar and distributary‐channel sandstones. Analysis of laminae bundling in the Pride Shale reveals a hierarchy of tidal cycles (semi‐diurnal, fortnightly neap‐spring) and a distinct annual cyclicity resulting from seasonal fluvial discharge. These tidal rhythmites thus represent high‐resolution chronometers that can be used in basin analysis. Annual cycles average 10 cm in thickness, thus the bulk of the Pride Shale‐Glady Fork Member in any one vertical section is estimated to have accumulated in ca. 600 years. Progradational clinoforms are assumed to have had dips of 0.3–3° with a median dip of 1.7°; the latter infilled a NE‐SW oriented foreland trough up to 300 km long by 50 km wide in the relatively short time period of 90 kyr. The total volume of sediment in the Pride basin is ca. 900 km3 which, for an average sediment density of 2700 kg m?3, equates to a total mass of ca. 2.4 × 106 Mt. Thus, mass sediment load can be estimated as 27 Mt yr?1. For a drainage basin area of 89 000 km2, based on the scale of architectural channel elements and cross‐set thicknesses in the incised‐valley‐fill deposits of the underlying Princeton Formation, suspended sediment yields are estimated at ca. 310 t km?2 yr?1 equating to a mechanical denudation rate of ca. 0.116 mm yr?1. Calculated sediment yields and inferred denudation rates are comparable to modern rivers such as the Po and Fly and are compatible with a provenance of significant relief and a climate characterized by seasonal, monsoonal discharge. Inferred denudation rates also are consistent with average denudation rates for the Inner Piedmont Terrane of the Appalachians based on flexural modelling. The integration of stratigraphic architectural analysis with a novel chronometric application highlights the utility of sedimentary archives as a record of Earth surface dynamics.  相似文献   

9.
In this paper changes in the active layer of the high arctic coastal area in north‐west Spitsbergen, Svalbard are described. Analysis includes both the ground thawing depth and its near‐surface thermal structure. The study was conducted on the Kaffiøyra Plain (Svalbard) at several fixed sites, which represent places typical of the region: a sandy beach, a tundra plain and a moraine ridge. The results show that in recent years, at two measurement points a significantly deeper thawing was observed. In 1996–2012 on the beach and on the moraine the trend of active layer thickness change was +1.3 cm yr?1 and +2.5 cm yr?1, respectively. Generally, in the years 2008–2012 the mean thickness of the active layer in the Kaffiøyra region increased by 3% to 6%. Even at the spatially close sites, within similar environments, there are significant differences in the thickness of the active layer. Measurements show that significant changes also occurred in the thawed ground temperature. Mean values of the observed near‐surface temperature in recent years (2007–2011) were higher by more than 1.0°C, in comparison to the mean in the late 1970s.  相似文献   

10.
ABSTRACT The Rioja Trough is the foreland basin of the western Pyrenees (to the north) and the Cameros-Demanda Massif (to the south). This E–W elongated trough is about 120×35 km. It was filled with Tertiary continental deposits (upper Eocene to upper Miocene), reaching thicknesses between 2500 and 5000 m. Both margins of the Rioja Trough are large thrusts with horizontal displacements of more than 20 km basinward. Rocks that fill the basin originated in alluvial fan and playa-lake environments, with conglomerates in the proximal sectors grading into sandstones, mudstones, lacustrine limestones and evaporites in distal sectors. The Tertiary series are horizontal in the central parts of the basin, with several E–W monoclines caused by north-verging thrusts in the basement of the basin. Near the basin margins, the Tertiary units are folded and thrusted, with several syntectonic unconformities. Calculated velocities for the Cameros-Demanda thrust range from 0.02 to1.1 mm yr?1 (average 0.7 mm yr?1). The sedimentation rate near the southern basin margin varies between 2 and 20 cm 1000 yr?1 (average 10 cm 1000 yr?1). Deposition in the Rioja Trough was strongly controlled by tectonic activity throughout the Tertiary. Eight tectosedimentary units (R1 to R8) have been characterized. These are bounded by angular unconformities at the margins and breaks in the vertical trend of the sedimentary record toward the basin centre. Every tectosedimentary unit (except R6 and R8) shows a fining-upward/coarsening-upward trend, corresponding to tectonic retrogradations and progradations, respectively. The main source area during the Palaeogene was the Cameros-Demanda Massif, whose unroofing sequence was strongly dependent on tectonic activity. During the Neogene a longitudinal WNW–ESE drainage system, with short alluvial fans in the northern and southern margins, developed. The final shape and the evolution of the Rioja Trough are the result of crustal flexure in the northern border of the Iberian plate, linked to the emplacement of the southern Pyrenean thrust system, and intraplate thrusting with basement uplift at its southern margin.  相似文献   

11.
This study presents a growth curve developed from direct and indirect growth rates of Rhizocarpon geographicum lichens from study sites on Mounts Baker, Rainier, Adams, and Hood in the northern Cascade Range of the western USA. Our observations of direct growth rates are based on 31 measurements of 11 lichens growing on different surfaces. This direct growth rate dataset is complemented by indirect growth rates based on measurements of the largest lichen observed on 20 different surfaces over 24–33‐yr periods. The direct and indirect datasets produce statistically indistinguishable mean radial growth rates of 0.48 and 0.50 mm yr?1, respectively. Statistical analysis of zero and first order fits of our growth rate data suggests that lichen growth is best characterized by the average of our mean growth rate (zero order) models at 0.49 mm yr?1. Our revised growth curve for the study area extends the applicable range for dating rock surface in the study area to the seventeenth century, approximately 175 years longer than previous calibrated curves.  相似文献   

12.
The Sachette rock glacier is an active rock glacier located between 2660 and 2480 m a.s.l. in the Vanoise Massif, Northern French Alps (45° 29′ N, 6° 52′ E). In order to characterize its status as permafrost feature, shallow ground temperatures were monitored and the surface velocity measured by photogrammetry. The rock glacier exhibits near‐surface thermal regimes suggesting permafrost occurrence and also displays significant surface horizontal displacements (0.6–1.3 ± 0.6 m yr–1). In order to investigate its internal structure, a ground‐penetrating radar (GPR) survey was performed. Four constant‐offset GPR profiles were performed and analyzed to reconstruct the stratigraphy and model the radar wave velocity in two dimensions. Integration of the morphology, the velocity models and the stratigraphy revealed, in the upper half of the rock glacier, the good correspondence between widespread high radar wave velocities (>0.15–0.16 m ns–1) and strongly concave reflector structures. High radar wave velocity (0.165–0.170 m ns–1) is confirmed with the analysis of two punctual common mid‐point measurements in areas of exposed shallow pure ice. These evidences point towards the existence of a large buried body of ice in the upper part of the rock glacier. The rock glacier was interpreted to result from the former advance and decay of a glacier onto pre‐existing deposits, and from subsequent creep of the whole assemblage. Our study of the Sachette rock glacier thus highlights the rock glacier as a transitional landform involving the incorporation and preservation of glacier ice in permafrost environments with subsequent evolution arising from periglacial processes.  相似文献   

13.
Glacier Benito is a temperate outlet glacier on the west side of the North Patagonian Icefield. Rates of thinning and ablation were obtained using data collected by the British Joint Services Expedition in 1972/73 and subsequent data collected in 2007 and 2011. Ice‐front recession rates were based on dendrochronological dating for the terminal moraines and aerial and satellite imagery of the ice front in 1944, 1998 and 2002. Between the first Benito survey in 1973 and 2007, the lower glacier thinned by nearly 150 m at an average rate of 4.3 m yr?1 with the rate increasing to 6.1 m yr?1 between 2007 and 2011, a 28.7% increase during the latter period. Increases in ice movement and ablation were negligible: ice movement for 1973 and 2007 averaged 0.45 m day?1 and ablation averaged 0.05 m day?1. Ice front recession along the glacier's centre line from 1886 to 2002 was approximately 1860 m. Retreat rates between 1886 and 1944 averaged 8.9 m yr?1. Thereafter glacier asymmetry makes measurement along the glacier centre line unrepresentative of areal change until 1998 when symmetry was restored; retreat between 1944 and 1998 was 15.4 m yr?1. From 1998 to 2002 the rate increased dramatically to 127.2 m yr?1. Recession from the southern end of Benito's terminal moraine in the 1850s supports an early date for initial retreat of the Icefield's glaciers.  相似文献   

14.
The estimation of ice/snow accumulation is of great significance in quantifying the mass balance of ice sheets and variation in water resources. Improving the accuracy and reducing uncertainty has been a challenge for the estimation of annual accumulation over the Greenland ice sheet. In this study, we kriged and analyzed the spatial pattern of accumulation based on an observation data series including 315 points used in a recent research, plus 101 ice cores and snow pits and newly compiled 23 coastal weather station data. The estimated annual accumulation over the Greenland ice sheet is 31.2 g cm?2 yr?1, with a standard error of 0.9 g cm?2 yr?1. The main differences between the improved map developed in this study and the recently published accumulation maps are in the coastal areas, especially southeast and southwest regions. The analysis of accumulations versus elevation reveals the distribution patterns of accumulation over the Greenland ice sheet.  相似文献   

15.
As closed topographic depressions, sinkholes effectively divide karst regions into a series of subwatersheds, where swallets within each sinkhole define the downstream end of each subwatershed. Water and sediment are temporarily stored in sinkholes before continuing to underground streams. While pathways and travel times of water in karst terrain are commonly found using tracing techniques, such techniques do not provide information about the movement and travel time of sediment through these systems. This paper reviews the literature regarding sediment storage within sinkholes and presents a case study, the objective of which is to estimate the magnitude and timing of sediment deposition within three sinkholes in an urbanized area in Tennessee, United States of America. Sedimentation rates in sinkholes were estimated based on age determination of cultural artifacts (buried trash and coal fragments) and by 14C dating. For the three study sinkholes, minimum deposition rates (maximum residence times) were 15?cm?yr ?1(6 yrs), 1.5?cm?yr ?1(81?yrs), and 0.2?cm?yr?1(640 yrs). The analysis revealed that sinkholes undergo fill and flush cycles at different timescales caused by changes in upland sediment supply and morphologic changes at swallet openings. Sinkholes that lack swallet openings, or with swallets that have become blocked by debris, are effectively disconnected from master streams with regard to sediment. Sediment stored in sinkholes may be released downstream when swallet conditions change.  相似文献   

16.
We present a new palaeogeographic reconstruction of the Helvetic zone based on the palinspastic restoration of 18 recently published and new retrodeformed structural cross‐sections through the Swiss Alps, Haute Savoie (France) and Vorarlberg (Austria). The reconstruction resulted in two palaeogeographic maps, one of the pre‐Mesozoic basement, the other for the sedimentary cover of the Helvetic shelf including the Nummulitic deposits of the Palaeocene–Eocene, which mark the onset of the North Alpine Foreland Basin of the Alps. Based on the palaeogeographic maps and a precise dating of the Nummulitic deposits, we established maps of the facies distribution including the estimated positions of the ancient coastlines and their evolution through time. The North Alpine Foreland Basin started as a narrow flysch basin in Palaeocene–Eocene times. Emplacement of the Penninic nappes led to the formation of a mélange on the active margin of this basin. This early foreland basin and its active margin migrated to the NW in Early Eocene times at a rate of about 10 mm yr?1. The maps also reveal a general progressive north‐ and westward propagation of the Eocene coastline between 50–34 Ma and during the Oligocene until approximately 32 Ma. Coastline propagation reveals strongly varying rates both spatially and temporally, and is ca. 1–2 mm yr?1 between 50 and 37 Ma and approximately 20 mm yr?1 between 37 and 32 Ma. Evolution and orientation of the Tertiary coastlines infers that the early development of the North Alpine Foreland Basin was mainly controlled initially by eustatic sea‐level fluctuations superimposed on flexural subsidence. After 37 Ma, we suggest a tectonically controlled coastline evolution in response to the collision of the European and Adriatic margins.  相似文献   

17.
Rates and impacts of atmospheric nitrogen (N) deposition are poorly understood in arid land ecosystems where soils are typically low in plant available N. To address this issue, we quantified long-term trends in N deposition and estimated its impact on plant community structure in the northern Chihuahuan desert of Central New Mexico, USA. Annual and seasonal rates of N deposition were strongly positively correlated with precipitation. When precipitation effects were removed statistically, N deposition increased at an annual rate of 0.049 kg ha−1 yr−1 between 1989 and 2004. Based on two independent fertilization studies at our desert grassland field site, continued atmospheric inputs are likely to increase grass cover, decrease legume abundance, and may favor blue grama (Bouteloua gracilis) at the expense of the current dominant species, black grama (Bouteloua eriopoda). We conclude that, although arid lands have low rates of N deposition and are primarily water limited, observed trends in N deposition rates may lead to significant changes in plant community structure.  相似文献   

18.
Glaciological investigations of the Upper Fremont Glacier in the Wind River Range of Wyoming were conducted during 1990–1991. The glaciological data will provide baseline information for monitoring future changes to the glacier and support ongoing research utilizing glacial-ice-core composition to reconstruct paleoenvironmental records. Ice thickness, determined by radio-echo sounding, ranged from 60 to 172 m in the upper half of the glacier. Radio-echo sounding of ice thickness at one point was confirmed by drilling 159.7 m to bedrock. The difference between radio-echo sounding depth and measured drilling depth was about 4 m. Annual ablation (including snow, firn, and ice) measured for the 1990–1991 period averaged about 0.93 m/a. Densification proceeds rapidly on Upper Fremont Glacier. Measured densities in the near-surface parts of the glacier ranged from 4.4 x 105 g/m3 at the surface to larger than 8.5 x 105 g/m3 at depths exceeding 14 m. Surface ice velocity and direction were monitored from July 1990 to August 1991. Ice velocity decreased in a downslope direction. The largest measured velocity was about 3.1 m/a and the smallest was 0.8 m/a. The yearly mean air temperature of the study site during the period from July 11, 1990 to July 10, 1991 was -6.9°. Borehole temperatures from 10-m depths are 0 ± 0.4°. The warmer borehole temperatures relative to the yearly mean air temperature may be caused by the latent heat of freezing, as meltwater from the surface percolates into the glacier and refreezes. [Key words: glaciers, Wyoming, Wind River Range, ice thickness, ablation rates.]  相似文献   

19.
Norikazu Matsuoka   《Geomorphology》2008,99(1-4):353-368
Rates and processes of frost weathering in the Alps were investigated by visual observations of intensively shattered rocks, continuous monitoring of frost wedging and rock temperatures in bedrock and measurements of rockfall activity. Rapid frost weathering of hard-intact rocks occurs along lakes and streams where seasonal freezing promotes ice segregation in the rock. Otherwise, rocks require pre-existing weakness or a long exposure period for intensively shattered. Automated monitoring shows that crack opening occurs at three scales, including small opening accompanying short-term frost cycles, slightly larger movements during seasonal freezing and occasional large opening originating from refreezing of snow-melt water during seasonal thawing. The opening events require at least partial water saturation in the crack. The repetition of crack opening (frost wedging) results in permanent opening and finally debris dislocation. Debris collections below fractured rockwalls show that pebble falls occur at an average rate of about 0.1 mm a− 1 with significant spatial and inter-annual variations. Occasional large boulder falls significantly raise the rockwall erosion rates, controlled by such factors as the joint distribution in the bedrock, repetition of annual freeze–thaw cycles and extraordinary summer thaw.  相似文献   

20.
Quantifying the contributions of climate change and human activities to ecosystem evapotranspiration (ET) and gross primary productivity (GPP) changes is important for adaptation assessment and sustainable development. Spatiotemporal patterns of ET and GPP were estimated from 2000 to 2014 over North China Plain (NCP) with a physical and remote sensing-based model. The contributions of climate change and human activities to ET and GPP trends were separated and quantified by the first difference de-trending method and multivariate regression. Results showed that annual ET and GPP increased weakly, with climate change and human activities contributing 0.188 mm yr–2 and 0.466 mm yr–2 to ET trend of 0.654 mm yr–2, and–1.321 g C m–2 yr–2 and 7.542 g C m–2 yr–2 to GPP trend of 6.221 g C m–2 yr–2, respectively. In cropland, the increasing trends mainly occurred in wheat growing stage; the contributions of climate change to wheat and maize were both negative. Precipitation and sunshine duration were the major climatic factors regulating ET and GPP trends. It is concluded that human activities are the main drivers to the long term tendencies of water consumption and gross primary productivity in the NCP.  相似文献   

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