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1.
Suspended sediment concentration is a major variable influencing soil erosion and loss, study on which at different spatial
scales is of great meaning to understand soil erosion mechanism and sediment transport process. Based on data from 4 sloping
surfaces and 7 basins ranging from 0.0003 to 187 km2 in area, the suspended sediment concentration in flood season (SSC) with drainage area is studied. With increasing drainage
area on the slope surfaces, the mean suspended sediment concentration in flood season (MSSC) enhances continuously until a
peak value of 685 kg m−3 occurs at the whole slope surface No. 7 runoff plot resulting from harder and harder erosion forms downslope. Entering basin
systems, the diluted action of subsurface water on the toeslope on MSSC and small water flow power Ω make a minimum MSSC value
of 568 kg m−3 occur in the first-order basin system Tuanshangou basin at an area of 0.18 km2, and then from Tuanshangou basin to larger basins, the positive feedback function among drainage density, water flow energy,
and hyperconcentrated flow as well as its reduction of settling velocity of coarser particles generates continuously increasing
MSSC with drainage area. 相似文献
2.
Bed sediment-associated trace metals in an urban stream, Oahu, Hawaii 总被引:78,自引:0,他引:78
R. A. Sutherland 《Environmental Geology》2000,39(6):611-627
Of the 117 stream and lake systems sampled nationwide, fish from Manoa Stream on Oahu, Hawaii, have consistently shown the
highest Pb concentrations. Therefore a detailed study was conducted to examine total metal contents in bed sediments from
a 5.8-km stretch of Manoa Stream. A total of 123 samples (<63 μm) were examined for 18 elements and 14 samples for 21 elements.
Selected samples were also examined using different leach solutions to examine metal phase associations. All trace metal data,
computations of enrichment ratios and the modified index of geoaccumulation point to mineralogical control for Cr and Ni;
minor anthropogenic contamination for Ba, Cd, Cu, Hg and Zn; and a very strong contamination signal for Pb. Maximum Pb contents
(up to 1080 mg kg−1) were associated with anthropogenic material dumping in minor tributaries, storm sewer sediments and sediments in the “lower”
section of the basin. Proportionally Pb had the highest non-residual component of elements examined; dominantly in the reducible
phase associated with Mn and amorphous Fe oxyhydroxides. The contamination signal was typically lowest in the “undisturbed”
headwater reach of the basin (above 5.1 km) with significant increases throughout the “residential” and “commercial-institutional”
zones of the mid-basin. The spatial pattern of bed sediment contamination and evidence from storm sewer-outlet sediments strongly
indicates that Pb, and to a lesser degree some other metals, is still being transported to the stream and the primary agent
is soil erosion and transport of metals sorbed to sediments. The primary source of sediment-associated metals is considered
to be the automobile, though other minor sources can not be ruled out.
Received: 3 November 1998 · Accepted: 26 January 1999 相似文献
3.
Soil erosion modeling of a Himalayan watershed using RS and GIS 总被引:5,自引:1,他引:4
Ashish Pandey Abhisekh Mathur S. K. Mishra B. C. Mal 《Environmental Earth Sciences》2009,59(2):399-410
Employing the remote sensing (RS) and geographical information system (GIS), an assessment of sediment yield from Dikrong
river basin of Arunachal Pradesh (India) has been presented in this paper. For prediction of soil erosion, the Morgan-Morgan
and Finney (MMF) model and the universal soil loss equation (USLE) have been utilized at a spatial grid scale of 100 m × 100 m,
an operational unit. The average annual soil loss from the Dikrong river basin is estimated as 75.66 and 57.06 t ha−1 year−1 using MMF and USLE models, respectively. The watershed area falling under the identified very high, severe, and very severe
zones of soil erosion need immediate attention for soil conservation. 相似文献
4.
Study on the runoff and sediment-producing effects of precipitation in headwater areas of the Yangtze River and Yellow River,China 总被引:2,自引:0,他引:2
Natural runoff observation fields with different vegetation coverage were established in the Zuomaoxikongqu River basin in
the headwater area of the Yangtze River, and in the Natong River basin and the Kuarewaerma River basin in the headwater area
of the Yellow River, China. The experiments were conducted using natural precipitation and artificially simulated precipitation
between July and August to study the runoff and sediment-producing effects of precipitation under the conditions of the same
slope and different alpine meadow land with coverage in the headwater areas. The results show that, in the three small river
basins in the headwater areas of the Yangtze and the Yellow Rivers, the surface runoff yield on the 30° slope surface of the
alpine meadow land with a vegetation cover of 30% is markedly larger than that of the fields with a vegetation cover of 95,
92, and 68%. Furthermore, the sediment yield is also obviously larger than the latter three; on an average, the sediment yield
caused by a single precipitation event is 2–4 times as large as the latter three. Several typical precipitation forms affecting
the runoff yield on the slope surface also influence the process. No matter how the surface
conditions are; the rainfall is still the main precipitation form causing soil erosion. In some forms of precipitation, such
as the greatest snow melting as water runoff, the
sediment yield is minimal. Under the condition of the same precipitation amount, snowfall can obviously increase the runoff
yield, roughly 2.1–3.5 times as compared to the combined runoff yield of the Sleet or that of rainfall alone; but meanwhile,
the sediment yield and soil erosion rate decrease, roughly decreasing by 45.4–80.3%. High vegetation cover can effectively
decrease the runoff-induced erosion. This experimental result is consistent in the three river basins in the headwater areas
of the Yangtze and Yellow Rivers. 相似文献
5.
Acidification is the most common water quality problem in lakes created from previous open cast lignite mines. Aeration of
aquifers and dump materials from mining activities causes pyrite oxidation. Pyrite oxidation products are stored in pore water,
minerals and at the exchange complexes of the aquifers and dump sediments. Rainfall runoff transports sediments on the dump
slope into the lakes. Elutriation of these sediments whithin the lakes releases either acid-producing or acid-neutralizing
agents. At a test site south of Leipzig, the annual erosion rates were quantified by water erosion models (RUSLE, EROSION
2D, PEPP) and field measurements. They ranged from 300 up to 900 tons per hectare. Hydrogen ion equivalent release or binding
at the sediment elutriation was computed from laboratory analysis of the pore-water quality, ion exchange complex and mineral
composition of the sediment. Two of the three investigated sediments contained 3 mmol (eq) acidity per 100 g dry sediment
and revealed saturation with respect to jarosite, jurbanite and gypsum. In the third sediment, 6 mmol (eq) alkalinity per
100 g dry sediment was obtained. The annual net acidity influx was calculated to be about 0.5 million mol (eq) for the lake
of the test site.
Received: 2 November 1998 · Accepted: 26 January 1999 相似文献
6.
Estimating suspended sediment yield, sedimentation controls and impacts in the Mellah Catchment of Northern Algeria 总被引:1,自引:0,他引:1
This paper is an assessment of the suspended sediment yield in the Mellah Catchment of northern Algeria. We use discharge–sediment load relationships to explore the variability of water discharge and sediment load, and to investigate the impact of geomorphic factors disturbance on erosion and sedimentation. Suspended sediment load was analyzed in the Mellah Catchment (550 km²) which was controlled by a gauging station to measure discharge and sediment transport. The relations between daily mean sediment concentration and daily mean water discharge were analyzed to develop sediment rating curves. For storms with no water samples, a sediment rating curve was developed. The technique involves stratification of data into discharge-based classes, the mean of which are used to fit a rating curve according to single flow data and season to provide various rating relationships. The mean annual sediment yield during the 24 years of the study period was 562 T km?2 in the Mellah Catchment. This drainage basin had high rainfall and runoff, the erosion was high. The high sediment yield in the Mellah basin could be explained by a high percentage of sparse grassland and cultivation developed on shallow marly silty-clayey soils with steep slopes often exceeding 12%. Almost all suspended sediment loads are transported during storm events that mainly occur in the winter and spring heavy and medium downpours. The scarceness of these events leads to a very large interseasonal variability of the wadi sediment fluxes. The negative impacts of this enhanced sediment mobility are directly felt in the western part of the basin which shows many mass movements, bank and gully erosion because cultivated areas are often bared during autumnal brief flash floods and furrowed downslope during the winter season. 相似文献
7.
Shallow landslide hazard assessment using a physically based model and digital elevation data 总被引:6,自引:1,他引:5
A model for the analysis of topographic influence on shallow landslide initiation is applied to an experimental mountain
basin where high-resolution digital elevation data are available: the Cordon catchment (5 km2) located in northern Italy. The model delineates those areas most prone to shallow landsliding due to surface topographic
effects on hydrologic response. The model is composed of two parts: a steady-state model for shallow sub-surface runoff and
an infinite-slope Coulomb failure model which assumes that the soil is cohesionless at failure. An inventory of landslide
scars is used to document sites of instability and to provide a test of model performance by comparing observed landslide
locations with model predictions. The model reproduces the observed distribution of landslide locations in a consistent way,
although spatial variations in soil strength and transmissivity, which are not accounted for in the model, influence specific
distribution of landslide areas within regions of similar topographic control.
Received: 15 October 1996 · Accepted: 25 June 1997 相似文献
8.
The rate of strontium sorption and the effects of variable aqueous concentrations of sodium and potassium on strontium sorption
were measured as part of an investigation to determine strontium chemical transport properties of a surficial sediment at
the Idaho National Engineering Laboratory (INEL), Idaho. Batch experimental techniques were used to determine the rate of
strontium sorption and strontium distribution coefficients (Kds) between aqueous and solid phases. Rate experiments indicate that strontium in solution reached an apparent equilibrium
with the sediment in 26 h. Kds were derived using the linear isotherm model at initial sodium concentrations from 100 to 5,000 mg/l and initial potassium
concentrations from 2 to 150 mg/l. Kds ranged from 56±2 to 62±3 ml/g at initial aqueous concentrations of sodium and potassium equal to or less than 300 and 150 mg/l,
respectively. Kds ranged from 4.7±0.2 to 19±1 ml/g with initial aqueous concentrations of sodium between 1,000 and 5,000 mg/l. These data
indicate that sodium concentrations greater than 300 mg/l in wastewater increase the availability of strontium for transport
beneath waste disposal ponds at the INEL by decreasing strontium sorption on the surficial sediment. Wastewater concentrations
of sodium and potassium less than 300 and 150 mg/l, respectively, have little effect on the availability of strontium for
transport.
Received: 6 February 1997 · Accepted: 31 March 1997 相似文献
9.
Some rainfall-related thresholds for erosion and sediment yield in the upper Yangtze River basin 总被引:1,自引:0,他引:1
Jiongxin Xu 《Environmental Geology》2009,56(6):1183-1192
This study examines rainfall thresholds for erosion and sediment yield in the upper Yangtze River basin. Sediment reduction
effects of soil conservation measures depend on the magnitudes of rainstorm. When the latter is less than a critical threshold,
sediment reduction effects of soil conservation measures are positive; when this magnitude is exceeded, the effect is negative.
An analysis based on data from the Jialingjiang River shows that the sediment reduction by soil conservation measures increased
with annual precipitation to a peak, and then decreased to a negative value. The annual precipitation at the peak and zero
values of sediment reduction are 970 and 1,180 mm, respectively, which can be regarded as two thresholds. Annual precipitation
at the zero-value of sediment reduction has a return period of 25 years. In general, the design standard of soil conservation
works in China is related with rainstorms with return periods of 10–20 years. When the magnitude of rainstorm exceeds this,
the soil conservation works may be partly or totally destroyed by rainstorms, and the previously trapped sediment may be released,
resulting in a sharp increase in sediment yield. It was also found in the lower Jinshajiang River that when annual precipitation
exceeds 1,050 mm or high-flow season precipitation exceeds 850 mm, the annual sediment yield increased sharply. These can
also be regarded as key rainfall thresholds for erosion and sediment yields. When precipitation is less than the two thresholds,
dominant erosion types are sheet, rill and gully erosions. When precipitation crosses the two thresholds, debris flows may
occur more frequently. As a result, the previously stored loose sediment is released and sediment yield increases sharply. 相似文献
10.
By employing a complete observation system, the underground erosion in a typical large-scale crystalline schist landslide
in Japan, the Zentoku landslide, was studied. It was found that the seasonal heavy rainfall is the main factor leading to
the massive underground erosion. Two types of sediment discharge of the landslide were defined. Monitored data indicated that
the movement of Zentoku landslide could be affected by the underground erosion following the concentrated heavy rainfall.
The influence of the underground erosion on the movement of the landslide presents different features. For the sliding block
of shallow and medium depth shear zones (5–20 m), the influence of the underground erosion is most outstanding, while it is
negligible for the sliding block of thick soil and rock layers (>30 m). Finally, the rainfall thresholds for the Zentoku landslide,
which concern the groundwater state, underground erosion and movement of sliding blocks, were provided to further establish
the warning and evacuation system. 相似文献
11.
Spatial distribution of soil erosion and suspended sediment transport rate for Chou-Shui river basin
Chin-Ping Lin Ching-Nuo Chen Yu-Min Wang Chih-Heng Tsai Chang-Tai Tsai 《Journal of Earth System Science》2014,123(7):1517-1539
In this study, a Physiographic Soil Erosion–Deposition Model (PSED) is applied for better management of a watershed. The PSED model can effectively evaluate the key parameters of watershed management: surface runoff discharge, suspended sediment transport rate, quantity of soil erosion, and spatial distribution of soil erosion and deposition. A basin usually contains multiple watersheds. These watersheds may have complex topography and heterogeneous physiographic properties. The PSED model, containing a physiographic rainfall-runoff model and a basin scale erosion–deposition model, can simulate the physical mechanism of the entire erosion process based on a detailed calculation of bed-load transportation, surface soil entrainment, and the deposition mechanism. With the assistance of Geographic Information Systems (GIS), the PSED model can handle and analyze extremely large hydrologic and physiographic datasets and simulate the physical erosion process without the need for simplification. We verified the PSED model using three typhoon events and 40 rainfall events. The application of PSED to Chou-Shui River basin shows that the PSED model can accurately estimate discharge hydrographs, suspended sediment transport rates, and sediment yield. Additionally, we obtained reasonable quantities of soil erosion as well as the spatial distribution of soil erosion and deposition. The results show that the PSED model is capable of calculating spatially distributed soil erosion and suspended sediment transport rates for a basin with multiple watersheds even if these watersheds have complex topography and heterogeneous physiographic properties. 相似文献
12.
V. V. S. Gurunadha Rao R. L. Dhar T. Jayachand C. S. Khoker 《Environmental Geology》2000,39(10):1138-1146
Mathura oil refinery was commissioned during 1977 and effluent storage ponds were constructed at the same time. These storage
ponds receive wastewater from the refinery at a rate of 10000 m3/day. After treatment, waste water is discharged through a 3-km pipeline to a stream leading to the Yamuna river. The groundwater-monitoring
as well as water-quality monitoring was carried at 24 observation wells in the refinery site during 1997. The water quality
measurements indicated total dissolved chloride and sulphate concentration of native groundwater as 400 mg/l, whereas elevated
levels up to 600 mg/l were found at the wells close to polishing ponds. Thus combined transport of chloride and sulphate was
simulated in the mass transport model. A three-dimensional flow, pathlines and mass transport model of the aquifer system
were constructed to analyze the impact of seepage from polishing ponds contaminating the groundwater regime. The permeability
of aquifer varies between 1.5–2.5 m/day. The porosity of formation was assumed as 0.2. The constant head and constant concentration
boundaries were assigned to the nodes representing effluent storage ponds. Longitudinal dispersivity of 100 m, horizontal
transverse dispersivity of 10 m and vertical transverse dispersivity of 0.01 m were assumed. The mass transport model was
calibrated for 20 years by comparing total dissolved chloride and sulphate concentrations from 1997. The model predictions
indicate further migration of contaminants on the east of effluent ponds in future.
Received: 4 January 1999 · Accepted: 12 July 1999 相似文献
13.
Suspended sediments in the Kharaa River catchment (Mongolia) and its impact on hyporheic zone functions 总被引:2,自引:2,他引:0
Melanie Hartwig Philipp Theuring Michael Rode Dietrich Borchardt 《Environmental Earth Sciences》2012,65(5):1535-1546
A previous study investigating the ecological status of the Kharaa River in Northern Mongolia reported fine-grained sediments
as being a major stress factor causing adverse impacts on the benthic ecology. However, the source of these sediments within
the catchment as well as the specific impact on hyporheic zone functions in the Kharaa River remained unclear. Therefore,
the objective of the current study was to investigate the underlying source–receptor system and implement an integrated monitoring
approach. Suspended sediment sources within the Kharaa catchment were identified by using extensive spatially distributed
sediment sampling and geochemical and isotope fingerprinting methods. On the receptor side, the ecological implications across
a gradient of fine-grained sediment influx were analyzed using a distinct hyporheic zone monitoring scheme at three representative
river reaches along the Kharaa River. Results of suspended sediment source monitoring show that during snowmelt runoff, riverbank
and gully erosion were the dominant sources. During the summer period, upland erosion contributed a substantial share of suspended
sediment. Fine-grained sediment influx proved to be the cause of habitat loss in the hyporheic zone and benthic oxygen production
limitation. This combined catchment and in-stream monitoring approach will allow for a better understanding and spatially
explicit analysis of the interactions of suspended sediment transport and hyporheic zone functioning. This information has
built the basis for a coupled modeling framework that will help to develop efficient management measures within the Kharaa
River basin with special emphasis on rapidly changing land-use and climatic conditions. 相似文献
14.
Controls of surface erosion on the evolution of the Alps: constraints from the stratigraphies of the adjacent foreland basins 总被引:5,自引:0,他引:5
F. Schlunegger 《International Journal of Earth Sciences》1999,88(2):285-304
The combined information about the stratigraphies from the foreland basins surrounding the Swiss Alps, exhumation mechanisms
and the structural evolution of the Alpine orogenic wedge allow an evaluation of the controls of erosion rates on large-scale
Alpine tectonic evolution. Volumetric data from the Molasse Basin and fining-upward trends in the Gonfolite Lombarda indicate
that at ∼20 Ma, average erosion rates in the Alps decreased by >50%. It appears that at that time, erosion rates decreased
more rapidly than crustal uplift rates. As a result, surface uplift occurred. Because of surface uplift, the drainage pattern
of the Alpine hinterland evolved from an across-strike to the present-day along-strike orientation. Furthermore, the decrease
of average erosion rates at ∼20 Ma coincides with initiation of a phase of thrusting in the Jura Mountains and the Southern
Alpine nappes at ∼50 km distance from the pre-20-Ma thrust front. Coupled erosion-mechanical models of orogens suggest that
although rates of crustal convergence decreased between the Oligocene and the present, the reduction of average erosion rates
at ∼20 Ma was high enough to have significantly influenced initiation of the state of growth of the Swiss Alps at that time.
Received: 8 June 1998 / Accepted: 30 October 1998 相似文献
15.
常用的水土保持措施是退耕还林,但淮河流域是中国重要的农业产区,大规模实行退耕还林并不现实,所以通过调整耕地类型来减少水土流失可能是解决社会经济发展和生态保护矛盾的好方法。为研究不同耕地类型对流域水文要素及产沙的影响,考虑水田和旱地两种耕地类型对淮河息县水文站上游流域构建SWAT模型,构造A(实际耕地利用方式)、B(所有耕地为水田)和C(所有耕地为旱地)三种耕地类型情景,比较不同耕地类型情景下流域水文要素及产沙的变化情况。研究结果表明:所构建的SWAT模型在息县流域径流及泥沙模拟中具有良好的适用性,R2和NSE(Nash Sutcliffe Efficiency)均达到0.75以上;水田和旱地两种不同耕地类型对流域多年年均蒸散发及多年平均径流量影响较小,但对流域产沙量影响较大,在汛期更为明显,模拟期内每平方公里水田每年最多比旱地少产沙491.8t,平均每年少产沙约208.7t。采取水田耕种比旱地耕种更有利于减少息县流域内的水土流失。 相似文献
16.
Damian Steffen Fritz Schlunegger Frank Preusser 《International Journal of Earth Sciences》2010,99(8):1975-1989
This study investigates the connection between sediment aggradation, erosion and climate in a desert environment of the Majes
valley, southern Peru. Luminescence dating of terraces and fans shows that sediment aggradation correlates with wet time intervals
on the Altiplano, suggesting a climatic influence on the aggradation–degradation cycles. Major periods of aggradation occurred
between ~110–100, ~60–50 and 12–8 ka. More precipitation in the Majes catchment resulted in increased erosion and transportation
of sediment from the hillslopes into the trunk river. As a result, the sediment loads exceeded the transport capacity of the
Majes River and aggradation started in the lower reaches where the river gradient is less. Depletion of the hillslope sediment
reservoirs caused a relative increase in the capacity of the trunk river to entrain and transport sediment, resulting in erosion
of the previously deposited sediment. Consequently, although climate change may initiate a phase of sediment accumulation,
degradation can be triggered by an autocyclic negative feedback and does not have to be driven by climatic change. 相似文献
17.
Geomorphic considerations for erosion prediction 总被引:9,自引:0,他引:9
Current soil-erosion prediction technology addresses processes of rainsplash, overland-flow sediment transport, and rill
erosion in small watersheds. The effects of factors determining sediment yield from larger-scale drainage basins, in which
sediment movement is controlled by the combined small-scale processes and a complex set of channel and other basin-scale sediment-delivery
processes, such as soil creep, bioturbation, and accelerated erosion due to denudation of vegetation, have been poorly evaluated.
General suggestions are provided for the development of erosion-prediction technology at the geomorphic or drainage-basin
scale based on the separation of sediment-yield data for channel and geomorphic processes from those of field-scale soil loss.
An emerging technology must consider: (1) the effects on sediment yield of climate, geology and soils, topography, biotic
interactions with other soil processes, and land-use practices; (2) all processes of sediment delivery to a channel system;
and (3) the general tendency in most drainage basins for progressively greater sediment storage in the downstream direction.
Received: 8 November 1995 · Accepted: 20 November 1995 相似文献
18.
Tayebeh Zinati Shoa Saeedeh Nateghi Ahmad Nohegar Fazel Amiri Biswajeet Pradhan 《Arabian Journal of Geosciences》2014,7(7):2841-2850
Soil erosion and sediment yield from catchments are key limitations to achieving sustainable land use and maintaining water quality in nature. One of the important aspects in protecting the watershed is evaluation of sediment produced by statistical methods. Controlling sediment loading in protecting the watershed requires knowledge of soil erosion and sedimentation. Sediment yield is usually not available as a direct measurement but is estimated using geospatial models. One of the geospatial models for estimating sediment yield at the basin scale is sediment delivery ratio (SDR). The present study investigates the spatial SDR model in determining the sediment yield rate considering climate and physical factors of basin in geographic information system environment. This new approach was developed and tested on the Amammeh catchments in Iran. The validation of the model was evaluated using the Nash Sutcliffe efficiency coefficient. The developed model is not only conceptually easy and well suited to the local data needs but also requires less parameter, which offers less uncertainty in its application while meeting the intended purpose. The model is developed based on local data. The results predict strong variations in SDR from 0 in to 70 % in the uplands of the Basin. 相似文献
19.
Hydrogeologic data of 455 water wells comprising geologic logs, water qualities, and aquifer test results are analyzed to
determine hydrogeological characteristics, water quality, and sustainable yield of the groundwater resources of Cheju volcanic
island. The groundwater of the island occurs in unconsolidated pyroclastic deposits and clinkers interbedded in highly jointed
basaltic and andesitic rocks as high-level, basal, and parabasal groundwater under unconfined conditions. The total storage
of groundwater is estimated at about 44 billion m3. The average transmissivity and specific yield of the aquifer are at about 0.34 m2 s–1(29300 m2 day–1) and 0.12, respectively. The average annual precipitation is about 3.39 billion m3, of which 1.49 billion m3– equivalent to 44.0% of the total annual precipitation – is recharged into aquifers, with 0.638 billion m3 year–1 of runoff and 1.26 billion m3 year–1 of evapotranspiration. Based on a groundwater budget analysis, the sustainable yield is estimated at about 0.62 billion m3 year–1, equivalent to 41.6% of annual recharge. A low-permeability marine sedimentary formation (Sehwari formation), composed of
loosely cemented sandy silt, was recently found to be situated at 120±68 m below mean sea level. If the said marine sediment
is distributed as a basal formation of the freshwater zone of the island, most of its groundwater will be of parabasal type.
So the marine sediment is one of the most important hydrogeological boundaries and groundwater occurrences in the area.
Received: 16 January 1997 / Accepted: 16 June 1997 相似文献
20.
Generation of a landslide risk index map for Cuba using spatial multi-criteria evaluation 总被引:5,自引:2,他引:5
This paper explains the procedure for the generation of a landslide risk index map at national level in Cuba, using a semi-quantitative
model with ten indicator maps and a cell size of 90 × 90 m. The model was designed and implemented using spatial multi-criteria
evaluation techniques in a GIS system. Each indicator was processed, analysed and standardised according to its contribution
to hazard and vulnerability. The indicators were weighted using direct, pairwise comparison and rank-ordering weighting methods,
and weights were combined to obtain the final landslide risk index map. The results were analysed per physiographic region
and administrative units at provincial and municipal levels. The Sierra Maestra mountain system was found to have the largest
concentration of high landslide risk index values while the Nipe–Cristal–Baracoa system has the highest absolute values, although
they are more dispersed. The results obtained allow designing an appropriated landslide risk mitigation plan at national level
and to link the information to the national hurricane early warning system, allowing also warning and evacuation for landslide-prone
areas. 相似文献