共查询到20条相似文献,搜索用时 31 毫秒
1.
Utilization of Time-Based Meteorological Droughts to Investigate Occurrence of Streamflow Droughts 总被引:1,自引:0,他引:1
Ali Asghari Tabrizi Davar Khalili Ali Akbar Kamgar-Haghighi Shahrokh Zand-Parsa 《Water Resources Management》2010,24(15):4287-4306
Complexities of streamflow drought analyses motivate utilization of simple, alternative methods, which can provide timely
information for effective water resources management. For this purpose time-based meteorological drought characteristics,
identified by SPI
3 − month
, SPI
6 − month
and SPI
Anuual
are investigated. A boxplot approach is used to exclude non-rainy months from the analysis. Streamflow drought characteristics
are described by drought intensities, and are calculated by the threshold level method. The non-parametric Wilcoxon–Mann–Whitney
test is used to investigate relations between streamflow drought intensities and SPI
3 − month
, SPI
6 − month
and SPI
Anuual
. The study area is the Doroodzan Watershed and Reservoir in southwestern Iran, with four rain gauge and two hydrometric stations.
According to the results, most of time-based SPI values show significant relations (at 5% level of significance) with streamflow drought intensities. However, the most significant
relation is between SPI
Anuual
of Jamalbeik rain gauge station (centrally located in the study area) and drought intensities of Chamriz hydrometric station
(located at the reservoir inlet). Comparison of study results with available records of documented droughts, confirms applicability
of the proposed procedures. The SPI
Anuual
is based on one-year-ahead moving average rainfalls. Then, SPI
Anuual
of Jamalbeik station can be used to investigate occurrence of streamflow drought in Chamriz hydrometric station. 相似文献
2.
The hydrological cycle, a fundamental component of climate is likely to be altered in important ways due to climate change.
In this study, the historical daily runoff has been simulated for the Chenab River basin up to Salal gauging site using a
simple conceptual snowmelt model (SNOWMOD). The model has been used to study the impact of plausible hypothetical scenarios
of temperature and rainfall on the melt characteristics and daily runoff of the Chenab River basin. The average value of increase
in snowmelt runoff for T + 1°C, T + 2°C and T + 3°C scenarios are obtained to be 10, 28 and 43%, respectively. Whereas, the average value of increase in total streamflow
runoff for T + 1°C, T + 2°C and T + 3°C are obtained to be 7, 19 and 28%, respectively. Changes in rainfall by −10 and + 10% vary the average annual snowmelt
runoff over the T + 2°C scenario by −1% and + 1% only. The result shows that melt is much more sensitive to increase in temperature than to
rainfall. 相似文献
3.
Saralees Nadarajah 《Water Resources Management》2009,23(9):1843-1848
It is pointed out that Hantush’s M(α, β) and M*(α, β) functions, two functions that arise with respect to groundwater pumping modeling, are particular cases of the generalized
incomplete exponential functions known in the mathematics/statistics literature. Some relevant computational issues are discussed. 相似文献
4.
Yu. B. Mgalobelov 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2008,42(6):309-322
Results of investigation of variations in the stress-strain state of an “arch-dam–rock-bed” system on approaching the first
limiting state (loss of the system’s bearing capacity) are analyzed.
Translated from Gidrotekhnicheskoe Stroitel‘stvo, No. 9, September 2008, pp. 16–30. 相似文献
5.
Davar Khalili Tohid Farnoud Hamed Jamshidi Ali Akbar Kamgar-Haghighi Shahrokh Zand-Parsa 《Water Resources Management》2011,25(6):1737-1757
Comparability analyses are performed to investigate similarities/differences of the standard precipitation index (SPI) and the reconnaissance drought index (RDI), respectively, utilizing precipitation and ratio of precipitation over potential evapotranspiration (ET
0). Data are from stations with different climatic conditions in Iran. Drought characteristics of the 3-month, 6-month and
annual SPI and RDI time series are developed and Markov chain order dependencies are investigated by the Log-likelihood, AIC and BIC tests. Steady state probabilities and Markov chain characteristics, i.e., expected residence time in different drought classes
and time to reach “Near Normal” class are investigated. According to results, both indices exhibit an overall similar behaviour;
particularly, they follow the first order Markov chain dependency. However, climatic variability may produce some differences.
In several cases, the “Extremely Dry” class has received a more critical value by RDI. Furthermore, the expected residence time of “Near Normal” class and expected time to reach “Near Normal” class are quite
different in a number of cases. The results show that the RDI by utilizing the ET
0 can be very sensitive to climatic variability. This is rather important, since if the drought analyses are for agricultural
applications, utilization of the RDI would seem to serve a better purpose. 相似文献
6.
A. M. Tsvik I. A. Maksimov V. V. Koleganov 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2008,42(2):83-87
Characteristic specific features of the thermal regime of the “dam-bed” system are examined.
__________
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 2, February 2008, pp. 54–58. 相似文献
7.
G. P. Yanchevskaya 《Power Technology and Engineering (formerly Hydrotechnical Construction)》1973,7(4):326-332
Conclusions By means of the proposed nomograms it is possible to select at preliminary stages of design the economically advantageous
types and dimensions of linings of tunnels being driven in isotropic rocks. From an examination of the solutions obtained
from the nomograms, we can draw the following conclusions, which have also been included in the “Instructions on the Designing
of Hydraulic Tunnels,” namely: a) it is recommended to use concrete linings in tunnels with an inside diameter up to 6 m in
rocks withf
st=2–10 at internal water pressure heads not exceeding 20–90 m, respectively; here it is recommended to take into account the
economy of labor expenditures in comparison with other types of linings; b) reinforced-concrete linings should be used: in
weak rocks (f
st=0.5–1.0) at internal water heads to 40 m and in stronger rocks (f
st≥2) for tunnels with Di=5 and greater at heads to 50 m, and in strong rocks (f
st=15) to 140 m; c) two-layer linings with an inner reinforced-gunite ring up to 15 cm thick should be used at heads of 50 m
and greater in rock of medium strength and higher (f
st≥3); d) two-layer linings with an inner steel shell should be used in granular and soft rocks (f
st=0.5–1.0) with Di≥10 m, and also at neads of 40 m and greater for any tunnel sections in these rocks and in cases of the economic inexpediency
or structural impossibility of using other types of linings.
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 4, pp. 15–19, April, 1973. 相似文献
8.
G. N. Petrov V. G. Radchenko 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2009,43(2):91-98
The law governing variation in soil properties is examined.
Translated from Gidrotechnicheskoe Stroitel‘stvo, No. 2, February 2009, pp. 4–12. 相似文献
9.
V. V. Petrashkevich 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2008,42(5):268-272
Parameters of plane and curvilinear reticulated fish-discharging barriers are substantiated.
Translated from Gidrotekhnicheskoe Stroitel‘stvo, No. 7, July 2008, pp. 50 – 54. 相似文献
10.
Adaptation to Climate Change in the Management of a Canadian Water-Resources System Exploited for Hydropower 总被引:3,自引:2,他引:1
Marie Minville François Brissette Stéphane Krau Robert Leconte 《Water Resources Management》2009,23(14):2965-2986
The management adaptation potential of the Peribonka River water resource system (Quebec, Canada) is investigated in the context
of the evolution of climate change. The objective of this study is to evaluate the impacts on hydropower, power plant efficiency,
unproductive spills and reservoir reliability due to changes in the hydrological regimes. The climate change projections used
here are from the Canadian regional climate model (CRCM) nested by the Canadian-coupled global climate model (CGCM3) forced
with the SRES A2 greenhouse gas emission scenario. The hydrological regimes were simulated with the distributed hydrological
model Hydrotel. They were incorporated into a dynamic and stochastic optimization model in order to adapt the operating rules
of the water resource system annually, according to the evolution of the climate. The impacts were analyzed over the years
1961–2099, split into four periods for comparison purposes: control period (1961–1990), horizon 2020 (2010–2039), horizon
2050 (2040–2069) and horizon 2080 (2070–2099). The main results indicate that annual mean hydropower would decrease by 1.8%
for the period 2010–2039 and then increase by 9.3% and 18.3% during the periods 2040–2069 and 2070–2099, respectively. The
trend to increase is statistically significant starting from 2061 (Mann–Kendall with p = 5%). The change in the mean annual production is statistically significant for the 2040–2069 and 2070–2099 periods (t-test with p = 5%). Also, the change in the variance is significant for the periods 2010–2039, 2040–2069 and 2070–2099 (F-test). Annual mean unproductive spills would increase from 1961–2099, but the trend is not statistically significant. However,
the changes in the variance of the annual mean spills are significant in the periods 2010–2039, 2040–2069 and 2070–2099. Overall,
the reliability of a reservoir would decrease and the vulnerability increase as the climate changes. 相似文献
11.
Motivated by hydrological problems, the exact distributions of the sum X + Y, the product X
Y and the ratio X/(X + Y) are derived when X and Y are independent Pareto random variables. A detailed application of the results is provided to extreme rainfall data from
Florida. 相似文献
12.
N. V. Khanov 《Power Technology and Engineering (formerly Hydrotechnical Construction)》1997,31(11):694-698
Model studies of the hydraulic operating conditions of an eddy tunnel outlet with an inclined shaft showed that:
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 11, pp. 41–44, November, 1997. 相似文献
– | for regimes without delivery of air into the flow core with swirler parameterA=1.1 and with delivery of air for all values ofA, submergence of the outlet section of the conduit in the lower pool noticeably affects the size of the core and promotes the formation of a hydraulic jump zone along the tunnel; |
– | insignificant (in value) submergences of the exit section of the tunnel have little effect on the discharge capacity of the outlet (their differences is Δ=1.4% forA=0.6, Δ=2.71% forA=1.1, and submergence even increases the discharge of the outlet Δ=0.8% forA=0.83). |
– | delivery of air into the flow core has little effect on the discharge capacity of the structure, with the exception of the layout with a swirler withA=0.6 (Δ=4.31% forA=0.6, Δ=0.5%, and Δ=0.9% forA=1.1); |
– | considerable vacuums are observed for regimes without air in the flow core, the absolute values of which with increase ofA drop intensely from Hfc=−4.5 m to Hfc=−0.3m; |
– | delivery of air into the flow core markedly reduces the vacuums in it and their values are close to zero; |
– | with increase of swirler parameterA the area occupied by the flow at the end of the tunnel decreases; |
– | regimes without delivery of air into the flow core are the most favorable with respect to the conditions of the pressure distribution on the conduit walls; |
– | submergence on the downstream side does not lead to an increase of pressure on the conduit walls if the vacuum in the flow core increases simultaneously with this. |
13.
R. R. Sultanbekov 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2005,39(4):211-214
An analysis of methods of nonlinear computation of concrete dams is presented, which makes it possible to determine the margin
of the bearing capacity of the “structure – foundation” system.
__________
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 5, May 2005, pp. 42 – 45. 相似文献
14.
Soil Erosion Assessment in a Hilly Catchment of North Eastern India Using USLE, GIS and Remote Sensing 总被引:9,自引:1,他引:8
In the present study, soil erosion assessment of Dikrong river basin of Arunachal Pradesh (India) was carried out. The river
basin was divided into 200 × 200 m grid cells. The Arc Info 7.2 GIS software and RS (ERDAS IMAGINE 8.4 image processing software)
provided spatial input data and the USLE was used to predict the spatial distribution of the average annual soil loss on grid
basis. The average rainfall erositivity factor (R) for Dikrong river basin was found to be 1,894.6 MJ mm ha−1 h−1 year−1. The soil erodibility factor (K) with a magnitude of 0.055 t ha h ha−1 MJ−1 mm−1 is the highest, with 0.039 t ha h ha−1 MJ−1 mm−1 is the least for the watershed. The highest and lowest value of slope length factor (LS) is 53.5 and 5.39 respectively for the watershed. The highest and lowest values of crop management factor (C) were found out to be 0.004 and 1.0 respectively for the watershed. The highest and lowest value of conservation factor (P) were found to be 1 and 0.28 respectively for the watershed. The average annual soil loss of the Dikrong river basin is 51 t
ha−1 year−1. About 25.61% of the watershed area is found out to be under slight erosion class. Areas covered by moderate, high, very
high, severe and very severe erosion potential zones are 26.51%, 17.87%, 13.74%, 2.39% and 13.88% respectively. Therefore,
these areas need immediate attention from soil conservation point of view. 相似文献
15.
K. N. Anakhaev 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2008,42(5):273-276
Simplified analytical relationships, which make it possible to determine elliptic integrals in calculating various schemes
of potential (seepage) flows, are proposed.
Translated from Gidrotekhnicheskoe Stroitel‘stvo, No. 8, August 2008, pp. 5–7. 相似文献
16.
Yu. N. Alimov A. K. Belotelov K. M. Dobrodeev A. I. Leviush V. I. Pulyaev Yu. V. Usachev V. A. Feshchenko 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2005,39(6):355-358
The basic principles for construction of relay protection of the equipment of 330–750-kV networks and substations with the
use of microprocessor devices of series Shé2710 produced by the “éKRA” Research and Production Enterprise (Cheboksary) are
considered.
__________
Translated from élektricheskie Stantsii, No. 9, September 2005, pp. 42–45. 相似文献
17.
V. N. Durcheva S. M. Puchkova 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2006,40(2):71-78
Operation of the dam in a transitional mode is described.
__________
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 1, January 2006, pp. 8–15. 相似文献
18.
V. I. Bronshtein M. E. Proshev 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2008,42(3):137-143
Analyses are presented for verification of the earthquake resistance of a dam.
__________
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 4, April 2008, pp. 30–35. 相似文献
19.
É. S. Argal 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2006,40(5):275-281
Quality control of joint grouting includes analytical and instrument methods.
__________
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 8, pp. 9–16, August, 2006. 相似文献
20.
N. N. Abramov 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2008,42(3):133-136
Quality of soil compaction in the Trans-polar regionis assessed by geophysical methods.
__________
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 3, March 2008, pp. 34–37. 相似文献