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Table of Content

    20 June 2011, Volume 26 Issue 6 Previous Issue    Next Issue
    Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Study on Zero Growth Problem in Total Water Demand of China
    HE Xi-wu, GU Ding-fa, TANG Qing-wei
    2011, 26 (6):  901-909.  doi: 10.11849/zrzyxb.2011.06.001
    Abstract ( )   PDF (868KB) ( )   Save
    The research of zero growth problems in water demand for a country is not only an important content of its long-term prediction of the supply and demand of water resources,but also an important part of water demand management, which makes such research of forward-looking and strategic significance. This paper analyzes the relationship between the ratio of tertiary industry in GDP and the total water demands in developed countries and regions,and investigates when the zero growth in total water demand of China would come true and the maximum amount of water demand through the method of "industrial structure analysis". According to this method, when the proportion of tertiary industry in GDP of a country or a region reaches 60% around,the total water demand would realize zero growth (or negative growth). The total water demand of China would reach zero growth during 2026 to 2030, with the maximum amount of around 630 billion m3.
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    Research on "Sand-covered Reclaimed Crop Land" of Alkali-saline Soil
    ZHOU Dao-wei, TIAN Yu, WANG Min-ling, SONG Yan-tao, ZHANG Zheng-xiang
    2011, 26 (6):  910-918.  doi: 10.11849/zrzyxb.2011.06.002
    Abstract ( )   PDF (913KB) ( )   Save
    In order to reclaim alkali-saline land, we mixed the sandy soil to alkali-saline soil, then evaluated the chemical parameters of mixed soil and the crop seedling response under such grow condition. Sandy land in Horqin, alkali-saline land in Songnen Plain and Liaohe Plain besides watershed ridge of Songnen Plain watershed and Liaohe Plain watershed interlaced and overlapped in mosaic distribution, with an overlapping area up to 3.5 million hm2. It has the potential to be reclaimed as crop land of one million hm2. When 40%-60% of sandy soil was mixed, the salt content which indicated by EC reduced 20%-50%, and ESP reduced 40%-60%. The mixed soil could adapt to many crop's growth, such as corn, sunflower, etc. It is feasible to use sand-covered reclaimed crop land in the study area from theoretical and practical aspect.
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    Establishment of Balance of Cultivated Land in Chongqing
    LI Ping, SHAO Jing-an, ZHANG Zhen, WEI Chao-fu, QIU Dao-chi
    2011, 26 (6):  919-931.  doi: 10.11849/zrzyxb.2011.06.003
    Abstract ( )   PDF (1168KB) ( )   Save
    The tendency of quantity reduction and quality degradation of cultivated land is inevitable along with population explosion and economic development in China. Maintenance of dynamic equilibrium of the total cultivated land on the premise of protection quality of cultivated land was not only an urgent governmental action, but also was a serious scientific issue. Moreover, "protecting 1.8 billion mu of cultivated land red line" is to neither reduce the quantity of cultivated land nor debase the quality of cultivated land. Using ration indicator prediction, correlation analysis and double factor model, this paper firstly discussed quantity and quality of cultivated land in Chongqing, and predicted the need variability of built-up land in 2020 to reflect the current situation of cultivated land utilization; secondly it did researches in the potentiality of land consolidation and rehabilitation, and analyzed quantity-quality conversion of supplementary cultivated land; and finally it established the system of balance between land consolidation and rehabilitation and land occupation of construction projects in Chongqing. The results showed that, until 2020, the total quantity of cultivated land which was occupied by built-up land would reduce 58856.56 hm2, and the practical potential of land consolidation and rehabilitation could reach 89961.06 hm2. According to quantity-quality converted coefficient of supplementary cultivated land, the practical potential still reached 84239.54 hm2. On the whole, Chongqing was able to realize dynamic equilibrium of the total cultivated land. The system of balance between land consolidation and rehabilitation and land occupation of construction projects was established based on the quantity and quality of supplementary cultivated lands which were equal to occupied cultivated lands, and meanwhile it was put into practice through grading conversion to understand the maximum potential. It could provide scientific basis for instituting of the land management policy in Chongqing.
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    Study on the Adoption and Determinants of Agricultural Water Saving Technologies
    LIU Ya-ke, WANG Jin-xia, LI Yu-min, ZHANG Li-juan
    2011, 26 (6):  932-942.  doi: 10.11849/zrzyxb.2011.06.004
    Abstract ( )   PDF (959KB) ( )   Save
    Adopting agricultural water saving technologies has been considered as one of the important approaches to reduce the pressure of agricultural water use. In recent years, Chinese government has increased investment in agricultural water saving technologies. Due to lack of understanding on the adoption determinants, the adoption of water saving technologies have been substantially constrained. The overall goal of this paper is to sketch a picture of current status and past trends of agricultural water saving technologies in the Yellow and Haihe river basins, as well as to analyze the determinants of adoption. This paper conducts an empirical analysis by applying three year's panel data from field surveys in the Yellow and Haihe river basins. The results show that water-saving technologies are distributed widely and spread quickly but the depth of adoption in terms of sown area is low. The adoptions of traditional and household-based technologies are higher and have developed quickly due to their low capital requirement and easy adoption by individual household; while for the community-based technologies characterized by higher requirement for capital and collective actions, its adoption rate is low and its development is not so quick. In addition, policy support from government and water scarcity are two key factors affecting the adoption of agricultural water saving technologies. Therefore, if government wants to push the adoption of agricultural water saving technologies, technology extension polices and demonstration villages can be two important tools.
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    Nitrogen and Phosphorus Balance of Cropland at Regional Scale for Integrated Crop-Livestock Farming System in Two Different Areas
    WU Lan-fang, OUYANG Zhu, XIE Xiao-li
    2011, 26 (6):  943-954.  doi: 10.11849/zrzyxb.2011.06.005
    Abstract ( )   PDF (1316KB) ( )   Save
    The nitrogen (N) and phosphorus (P) balances of cropland within two different areas of crop-animal mixed farming system, Yucheng County, Shandong Province and Taoyuan County, Hunan Province were taken as the case study. The result shows that N and P input to the cropland has been increased since 1980, so is the case of N and P export. However, a large amount of N and P surplus was produced owing to the increasing input of N and P to cropland which is greater than the export, and there were differences between the two areas. In the cropland of Yucheng County, the surplus of N and P has been increasing year by year, annual N surplus per hectare of farmland was greatly increased from 133.8 kgN·hm-2 to over 450.0 kgN·hm-2, and annual P surplus per hectare farmland was increased from 6.2 kgP2O5·hm-2 to 148.9 kgP2O5·hm-2. As a result, in 11 villages and towns of Yucheng, 10 of them show N surplus and 9 of them have P surplus to different extent of which the largest amount of N surplus reaching 841.8 kgN·hm-2 and the P surplus 297.8 kgP2O5·hm-2. In the cropland of Taoyuan County, the surplus amount of both N and P were increased till 2002, and then began to decline. The N surplus increased from about 100.0 kgN·hm-2 to the ceiling amount of 253.7 kgN·hm-2, then decreased to the present about 150.0 kgN·hm-2, and the P surplus increased from about 20 kgP2O5·hm-2 to the peak of 95.9 kgP2O5·hm-2 and then decreased to about 34.4 kgP2O5·hm-2 at present. In 40 village and towns of Taoyuan County, 36 of them exhibit N surplus and 26 of them appear P surplus to different extent, of which the highest amount of N surplus is 561.7 kgN·hm-2and the highest amount of P surplus is 171.1 kgP2O5·hm-2. A great deal of N and P surplus resulted from either overuse of fertilizer or overload of manure within cropland, and the surplus amount of both N and P in Yucheng County is greater than that in Taoyuan County. To cut down N and P surplus and loss, fertilizer should be minimized as much as possible according to crops need, besides manure should be applied inside and outside the area according to the carrying capacity of cropland to manure.
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    Actual Nitrogen Rate and Its Multiple Effects in Rice-Wheat Rotation System of Taihu Lake Watershed: Empirical Analysis Based on Household Survey
    JIAO Wen-jun, MIN Qin-wen, CHENG Sheng-kui, LU Jia, YAN Li-zhen
    2011, 26 (6):  955-963.  doi: 10.11849/zrzyxb.2011.06.006
    Abstract ( )   PDF (992KB) ( )   Save
    The authors carried out a one-week household survey with stratified random sampling in Wujin District of Changzhou in 2009, then organized and analyzed data from a total of 237 questionnaires using SPSS statistical software. Main conclusions are as follows: 1) Actual nitrogen rate in rice-wheat rotation system of Taihu Lake Watershed was 513.09 kg·hm-2 per year with 310.91 kg·hm-2 in the rice season and 202.18 kg·hm-2 in the wheat season, which revealed that excessive application of nitrogen mainly existed in the rice season. 2) Nitrogen played an active role in increasing yield of rice and wheat, but their yield, nitrogen accumulation, agronomic efficiency and recovery efficiency tended to decrease when nitrogen rate climbed to a certain point. 3) Nitrogen surplus and loss continued to increase as nitrogen rate rose in rice-wheat rotation system of Taihu Lake Watershed and nitrogen loss was estimated to be 41.26 kg·hm-2 per year under current nitrogen rate.
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    Comprehensive Method for Evaluating Energy Security
    WU Chu-guo, HE Xian-jie, SHENG Chang-ming, LIU Zen-jie, WAN Hui
    2011, 26 (6):  964-970.  doi: 10.11849/zrzyxb.2011.06.007
    Abstract ( )   PDF (874KB) ( )   Save
    "Energy security" refers to capability and state that a country or a region may obtain stable, sufficient and clean energy supply to meet the requirements of ensuring prudent operation and sustainable and balanced development of its economy and society. For the evaluation of China's energy security situation, the technical key is how to quantitatively analyze the guarantee degree of energy supply under the multivariate energy structures, such as petroleum, gas, coal, civil nuclear and so on.We firstly design an evaluating system of energy security by ten factors from five aspects, according to three levels of "Composite Index-Essential Indicators-Key Factor". The five aspects are: 1) domestic energy supporting capability, 2) domestic production capacity, 3) ability of international market energy acquisition, 4) national emergency control ability, and 5) environmental safety control ability. And the ten factors include: 1) reserves-production ratio, 2) reserve replacement ratio, 3) production share, 4) self-sufficiency ratio, 5) import shares, 6) price, 7) reserves level, 8) energy consumption intensity, 9) carbon emissions, and 10) the proportion of clean energy. Then, we use the weighted aggregative model to make an integrated index of "energy security degree". Finally, the general state of energy security can be characterized and described by the integrated index.We choose 1 and 0 as the maximum and minimum of the value range of the integrated index, the higher the index, the safer the energy situation. Based on successive decrease of step width of 0.2, energy security degree is divided into five grades: safe, basically safe, unsafe, seriously unsafe and in crisis state, which correspond to five colors for early warning, they are in the order of green, blue, yellow, orange and red.Study indicates that currently the degree of China's energy security is 0.7125 averagely, being "basically safe". With proper future development programs and powerful measures, the degree of China's energy security will reach 0.8411 and 0.8477 respectively in 2020 and 2030, entering the "safe" interval. In case our country is implemented the energy blockade internationally, the indicator maybe decrease to 0.5520 of the state of "unsafe".To solve China's energy security, the key is to not only increase its strategic reserves, diversify the energy supply, strengthen geological exploration, develop alternative energy and raise energy efficiency, but also place energy diplomacy in a prominent position.
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    Changes of Citrus Climate Risk in Subtropics of China
    DUAN Hai-lai, QIAN Huai-sui, DU Yao-dong
    2011, 26 (6):  971-980.  doi: 10.11849/zrzyxb.2011.06.008
    Abstract ( )   PDF (1254KB) ( )   Save
    Based on the daily meteorological data of 273 stations from 1961 to 2005, simulated temperature and precipitation data under future climate scenarios (SRES A2), and by using citrus climate risk model, the climate risk for citrus in subtropics of China is studied. The results show that the changing rate and trend of citrus climate risk have different expressions in different zones, and citrus risk over the 46 years has an increasing trend, especially increasing rapidness from the early 1980s.The responses of citrus climate risk to global warming are different between the different zones, the study shows that the citrus climate risk decreases northward and in west mountainous area of subtropics of China, and the citrus climate risk increases in middle and south of subtropics of China, especially in middle of subtropics of China. So the northern part of subtropics of China will be suitable for the cultivation of citrus in the future, while the western region of subtropics which is unsuitable for citrus growing will become possible in the future.
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    Evolution of Household Energy Consumption Patterns Induced by Rural Tourism Development and Based on Household Survey Data
    XI Jian-chao, ZHAO Mei-feng, GE Quan-sheng
    2011, 26 (6):  981-991.  doi: 10.11849/zrzyxb.2011.06.009
    Abstract ( )   PDF (1192KB) ( )   Save
    Rural tourism has become one of the four main types of China's rural strategic transformation. Obviously, the rural tourism development would have far-reaching impact on pattern of rural household energy consumption. Based on eco-tourism area of Liupan Mountain household survey data, from the angle of per capita energy consumption from the household, structure, and end-use, the exploratory research farmers in rural tourism induced evolution of household energy consumption patterns was carried out. The results showed that the total energy consumption per capita of the rural tourism households was 42.96% higher than the traditional farmers, being 707.35 kgce. In energy consumption structure, commercial energy is dominant in the rural tourism farmers,new energy (solar energy) is widely used, the proportion of traditional energy is decreased. The ratio of the three is 93.10 ∶5.15 ∶1.75, and the proportion of the traditional farmers is 46.30 ∶0.48 ∶53.22. In energy use, what the farmers of rural tourism can use in daily life (cooking, heating, household appliances, transportation, hot water, lighting) increased substantially, the traditional breeding and agricultural machinery related to energy consumption was abandoned. Traditional farmers are still restricted to the energy consumed cooking, heating, three aspects of feeding, and enjoyment of life associated with household appliances, lighting, hot water, traffic levels are still relatively backward. The result showed that household energy consumption pattern is mainly due to changes in production by the family, the way of energy use, per capita income, subjective cognitive. The study concluded that induced by the rural tourism development, household energy consumption in Liupan Mountain ecological tourist area evolved from the inward-looking "life-production system" self-loop model to an outward-oriented"life-travel system ".
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    Combined Time Series Models for the Dynamic Analysis of the Fisheries Resources
    NI Hai-er, ZHOU Rui-juan
    2011, 26 (6):  992-1000.  doi: 10.11849/zrzyxb.2011.06.010
    Abstract ( )   PDF (834KB) ( )   Save
    The variation of fisheries resources is a random process. They vary with not only inherent tendency, but also random fluctuation. Combining grey system theory with time series analysis, the grey time series models were built. The varying tendency of fisheries resources was pick-up by GM(1,1), then the random fluctuation was characterized by time series models. In order to eliminate the effect of fishing effort on the variation of fisheries resources, the multivariable time series models were built relating catch to fishing effort and catch per unit effort (CPUE) to fishing effort. Using the grey time series models and multivariable time series models the dynamic analysis and prediction of the fisheries resources in Zhoushan Fishing Ground were made. It was showed that the grey time series models and multivariable time series models can accurately fit the varying process and predict the coming state of fisheries resources.
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    Wavelet Analysis on Annual Precipitation around 300 Years in Beijing Area
    LI Miao, XIA Jun, CHEN She-ming, MENG De-juan
    2011, 26 (6):  1001-1011.  doi: 10.11849/zrzyxb.2011.06.011
    Abstract ( )   PDF (1157KB) ( )   Save
    After making trend analysis and abrupt change analysis, a morlet wavelet analysis was used in this study for analyzing precipitation annual variability in about 300 years in Beijing Area. The complex construction of precipitation variability was revealed and precipitation period and mutation in multiple time scale was analyzed, finally a forecast about precipitation variability was made according to the main period. It is found that there exists a slowly increasing but non-significant trend for annual precipitation in Beijing Area, and the years of 1744, 1809, 1894 and 1996 are abrupt change points of annual precipitation reduction, while 1777, 1870 and 1948 are abrupt change points of annual rainfall increasing. Furthermore, the annual precipitation series in Beijing Area represents a non-uniform time-scale distribution in its calculation period with obvious local features. There exists a characteristic period of about 85-95 years for annual precipitation, while the periodic characteristics of 35-40 and 20-25 years are also relatively obvious. There are more or less alternatives changes in average precipitation at different time scales. Moreover, the analysis results show that there are main periods of 21 years, 35 years, and 85 years of which the 85-year period is the first order main period in this area. According to the first order main period, there will be a state of less precipitation in a period of 85 years after 2009 in Beijing Area.
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    Impacts of Land Use and Impervious Surface on Stream Flow Metrics in Chesapeake Bay Watershed
    TIAN Di, LI Xu-yong, Donald E. WELLER, BAI Zhong-ke
    2011, 26 (6):  1012-1020.  doi: 10.11849/zrzyxb.2011.06.012
    Abstract ( )   PDF (810KB) ( )   Save
    Using daily discharge data from the US Geological Survey, we calculated 34 stream flow metrics for 150 watersheds (area<282 km2) within the Chesapeake Bay basin, and selected 17 of the metrics. We quantified the proportions of forest, agriculture, grassland, developed land, and impervious surface in each watershed. For each of the three physiographic provinces, we correlated the flow metrics with the land cover proportions to elucidate how different land cover types affect the flow regime. Higher proportions of forest increased stream flow in relatively dry winters or springs and reduced stream flow in comparatively rainy autumns. Higher forest proportions also reduced flooding, prolonged pulses of higher flow, and reduced flow variability. Higher proportions of agriculture reduced flow variability and prolonged pulses of higher flow in all physiographic provinces and reduced flooding in the highland physiographic provinces. Higher grassland proportions reduced flooding and flow variability and prolonged high flow pulses in all provinces. Higher proportions of developed land and impervious surface reduced infiltration, increased flooding and flow during high rainfall periods, intensified flow variability, and shortened high flow pulses; there are different hydrologic effects in different urbanized areas.
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    Utilization and Spatial-Temporal Distribution of Wind Energy Resources in Henan Province Based on GIS
    ZHANG Hong-wei, CHEN Huai-liang, ZHANG Hong
    2011, 26 (6):  1021-1029.  doi: 10.11849/zrzyxb.2011.06.013
    Abstract ( )   PDF (1067KB) ( )   Save
    In recent years, wind power, a non-polluting, renewable green energy, has been developed and utilized faster than ever. For better utilization of wind energy resources and understanding wind energy changing trend under climate change condition in Henan Province, the spatial-temporal distribution of wind energy was studied in this paper with the meteorological data from 1971 to 2000, the statistical methods and wind energy calculation methods in hydrodynamics were used in this paper. The results show: 1) the special terrain characters create the features of higher wind speed mostly clustered in plain areas of northern Henan, central Henan, eastern Henan as well as southern Henan, western Henan is a zone with lower wind speed. 2) The wind changing trend reduced gradually from the 1970s to the 2000s in most parts of Henan Province except several districts. Eastern Henan has been tested to be the most serious zone in wind speed decrease, and other parts of Henan have a relative less value in wind speed decrease. 3) Wind energy's distribution was the same as wind speed, the highest wind-energy zone clustered in northern Henan, central Henan, eastern Henan and southern Henan, western Henan is a zone with lower wind energy.
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    Temporal and Spatial Distribution of the Drought in Anhui Province Based on the Balance Mechanism of Supply and Demand of Water Resources
    ZHOU Liang-guang, DAI Shi-bao, JIANG Yu-jing
    2011, 26 (6):  1030-1039.  doi: 10.11849/zrzyxb.2011.06.014
    Abstract ( )   PDF (887KB) ( )   Save
    Most drought studies are somewhat based on meteorological drought, hydrological drought and agricultural drought, then they can't reflect the contradiction between supply and demand better. According to the method of water supply and demand causing droughts, this paper studies the droughts of temporal and spatial distribution of Anhui Province from 2001 to 2005. It is concluded that the two years of 2001 and 2005 are the moderate level of drought, but the difference is very large. The drought index of 2005(DI 1.4859) that the river flow is normal is higher than the 2001 (DI 0.8909)that the flow is lower. On the whole, the drought of Anhui Province is moderate in 2005, but the regional difference is significant between cities. The cities with higher level of economic development and larger water resources consumption witness severe drought especially(such as Hefei,Huainan, Ma'anshan and Wuhu). Huaibei (DI -0.1461,no drought) and Wuhu(DI 2.4662,severe drought), with almost the same population and natural water resources quantity, have obviously different drought indexes. It is further found that the GDP differs one time between the two cities. It is concluded that the basic reason is the great different socio-economic development leading to different amount in water supply and demand. It is considered that the meteorological drought, agricultural drought and hydrological drought singly can't reflect the drought condition while socio-economic drought becomes more intuitive for the drought description. Using the method of water supply and demand balance mechanism for drought evaluation is more paractical in modern society.
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    Dynamic Analysis on the Industrial Water Withdrawal and Water Saving of Beijing in the Past 20 Years
    JIANG Lei, CHEN Yuan-sheng, LI Lu
    2011, 26 (6):  1040-1051.  doi: 10.11849/zrzyxb.2011.06.015
    Abstract ( )   PDF (1192KB) ( )   Save
    This paper gives an account of the dynamic changing process of the water withdrawal structure and the industrial water-use efficiency in Beijing during the years from 1988 to 2008. In this period, the water withdrawal structure of the three industries of Beijing changed from "1-2-3" type to "1-3-2" type in 2005, and is likely to change to "3-1-2" type in the next few years. Based on this, the macroscopic amount of water savings of three industries are calculated, which shows that the saved amount of industrial water withdrawal of Beijing caused by improving water-use efficiency of the tertiary industry amounted to 1.14 billion m3, which accounting for 38% of the total saved amount of industrial water withdrawal caused by improving water efficiency of three industries. And a multivariate regression model of the saved amount of water withdrawal caused by industrial structure upgrading is established, which explains that every 1% increase in the added value of the tertiary industry proportion, can save 0.344 billion m3 water. An empirical power exponent model of Beijing water withdrawal per ten thousand yuan GDP of industry-real GDP per capita, which shows that the period when the added value proportion of the tertiary industry increased from 40% to 70%, is the key period to vastly improve the water-use efficiency and the negative growth of water withdrawal of industries. The result reveals that the saved amount of industrial water withdrawal has been effectively elevated through actively developing tertiary industry and improving water-use efficiency. The author suggests that more attention should be paid to water-saving management, and the water-saving potential of the tertiary industry should be fully tapped.
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    Impact of Climate Change on Water Resources in Main Paddy Rice Cropping Regions in China
    MA Xin, WU Shao-hong, DAI Er-fu, ZHANG Xue-yan, KANG Xiang-wu, PAN Tao
    2011, 26 (6):  1052-1064.  doi: 10.11849/zrzyxb.2011.06.016
    Abstract ( )   PDF (122641KB) ( )   Save
    Based on both observed climate data and B2 climate scenario's data from PRECIS, the impact of climate change on water resources was simulated by using the VIC model. Comparison of runoff-depth between the average of 2001-2030 (B2, near term) and the average of 1981-2000 (B2, baseline period) shows that water resources would increase generally in the main paddy rice cropping regions, with a distribution trend of higher in south-east and lower in north-west. Calculated based on 28 second class watersheds in China's main paddy rice cropping regions, water resources increased from -48.5 mm to 269.1 mm, as such relative variation from -6.1% to 29.6%. Water resources would increase in the coastal areas of Qiantangjiang, Wajiang, Minjiang, Hanjiang, Mindong, Yuedong, Dongjiang and the watersheds of Taiwan's, and would decrease in coastal areas of west Guangdong, Guangxi and Hainan watersheds as well as in watersheds of Yuanjiang-Red River, mainstream of the upper reaches of Huanghe River, Jialingjiang, mainstream of Huaihe River. But the absolute decrease would not be much.
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    Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Adaptive Regulation Ant Colony System Algorithm-Radial Basis Function Neural Network Model and Application in Mid-long Term Runoff Prediction
    BAI Ji-zhong, SHI Biao, FENG Min-quan, ZHOU Li-kun
    2011, 26 (6):  1065-1074.  doi: 10.11849/zrzyxb.2011.06.017
    Abstract ( )   PDF (995KB) ( )   Save
    Runoff prediction is an important task of water conservancy departments. In order to improve the reservoir long-term runoff forecasting accuracy, adaptive regulation ant colony system algorithm (ARACS) is proposed. The forecast model is set up by using an adaptive regulation ant colony system algorithm and the radial basis function (RBF) neural network combined to form ARACS-RBF hybrid algorithm, and then training the neural network by using the ARACS algorithm. It can automatically determine the parameters of the neural network from the sample data and form the reservoir long-term runoff forecast model based on the hybrid algorithm. Then the reservoir long-term runoff forecast was carried out by using the method and history runoff data. In long-term runoff forecasting such factors impacting long-term runoff as meteorology, weather, rainfall and season are comprehensively considered. The results indicate that the method can reflect the general trend of the stream flow truly, which provides a new method to estimate the no linearity of time series. The result shows the convergence of method is faster and forecast accuracy is more accurate than that of the traditional ant colony system algorithm-RBF neural network and RBF neural network. The method improves forecast accuracy and improves the RBF neural network generalization capacity; it has a high computational precision, and in 98% of confidence level the average percentage error is no more than 6.5%. The hybrid algorithm can be used efficiaciously in long-term runoff forecasting of the reservoir and river.
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    Study on the Effect of Calcium Nodule on Soil Water Infiltration by Artificial Rainfall
    ZHOU Bei-bei, JIANG Yan-li, SHAO Ming-an, WEN Ming-xia
    2011, 26 (6):  1075-1082.  doi: 10.11849/zrzyxb.2011.06.018
    Abstract ( )   PDF (783KB) ( )   Save
    Based on the artificial rainfall experiment on the slope land, the effects of calcium nodule content (embedded in soil) and coverage on infiltration process were studied, as well as the infiltration rate and fitting parameters. The results showed that both of the calcium nodule content and coverage had obvious effects on recharge coefficient, while the effect of the former was much more obvious. The average infiltration rate and the stable infiltration rate decreased with the increase of calcium nodule content. Both of Kostiakov infiltration model and Philip equation could describe the rainfall infiltration process well.
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