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2005 Vol.3 No.2
Published 2005-06-30
Articles
1
JIANG De-Wen
Discussion on important techniques of sustainable development of small watershed comprehensive management
In order that techniques of small watershed comprehensive management can be brought into playing important role in the process of building a well-off society in an all-round way and sustainable development, a few important techniques were researched into and discussed for innovation and perfection. These techniques included the relation between small water comprehensive management and ecosystem self-rehabilitation, the measure adjustment of small watershed overall arrangement, perfection and innovation of small watershed management model, harmonious measure arrangement between human and nature, the capital farmland building, eco-water resource in eco-environment conservation, the control standard of soil erosion in comprehensive management and so on.
2005 Vol. 3 (2): 1-4 [
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5
JIN Fang-；Lu-Chao-Wei-；Tu-Xin-Xiao-；Rao-Liang-Yi-；Zhang-Zhen-Meng-；Mao-Fu-Ling
Preliminary study on evaluation index system of forest ecosystem services in China
With more and more thorough understandings of human beings that the function of ecosystem can not be substituted, the study of ecosystem service value is gradually paid great attention to. As the main body of land ecosystem, forest plays an important role in the global ecosystem. How to evaluate its service value and establish scientific, reasonable and feasible evaluation standard and index system become urgent problems in the present time. Considering thoroughly forest ecosystem service value mechanism, adopting frequency analysis and experts consultation methods, index system of forest ecosystem service evaluation in China has been preliminarily established.
2005 Vol. 3 (2): 5-9 [
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2140
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10
WANG Fei-；Mu-Xin-Min-；Zhang-Xiao-Ping-；Li-Dui
Effect of soil and water conservation on runoff and sediment in Pianguan River
Soil and water conservation is a significant measure to regulate runoff and sediment. The area of soil and water conservation increased from 1万1593hm
2
in 1959 to 5万5338hm
2
in 1996, accounting for 28.90% of the whole area. The annual runoff amount and constant runoff amount have significantly negative correlation with year and all soil and water conservation measures. The relationships between annual runoff amount and annual precipitation, precipitation in flood period （during May to September） and effective precipitation （daily amount more than 10?mm） are very significantly positive, but the relation of constant runoff amount with annual precipitation, precipitation in flood period and effective precipitation are weak. The water surface evaporation in Pianguan River basin decreased annually, but the trends of runoff and sediment were not increased because of the soil and water conservation. Annual runoff, runoff and sediment in flood period varied in the same trend that they have positive relationship with annual precipitation, precipitation in flood period and effective precipitation, but negative with areas of soil and water conservation measures.
2005 Vol. 3 (2): 10-14 [
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1535
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15
MA Xiang-Hua-；Jiao-Ju-Yang
Characteristics of vegetation with natural restoration in removal lands in loess hilly-gully region and the relationship between the characteristics and soil environment
To supply vegetation restoration and reconstruction of removal lands in loess hilly-gully region with scientific basis, based on the data of Ansai in the typical loess hilly-gully region, the vegetation communities were analysed using hierarchical cluster analysis and step by step regression procedure to classify the stages of vegetation succession with natural restoration and quantitatively determine the relationship between the communities and soil environmental factors. The results showed that the stages of succession on removal lands as follows:
Artemisia secoparia
community-Leymus
scalinus
community-Stipa
bungeana
community
Artemisia gmelinii community
、
Lespedeza daurica
community-
Bothriochloa
ischaemum
community. Rich indexes of Gleason and Margalef and Pielou index decrease with removal time passing by at first and then increase, Simpson index is relatively bigger at the early and later balance stages, and the trend of ecological dominance of the communities is opposite to that of species rich index. The contents of soil organic matter, total N, available N and readily available K increase and that of readily available P and soil PH value decrease in the process of succession. Soil surface density decreases and soil porosity increases.There is very significantly positive correlation between the contents of total N, available N, soil pH value in the layer A and the contents of total N in the layer C and species richness, and there is very significantly negative correlation between the contents of soil organic matter in the layer A,C and the contents of soil readily available K in the layer B and species richness. There is very significant and positive correlation between the contents of soil readily available P in the layer B and ecological dominance of the community. There is very significant and positive correlation between the contents of soil readily available K in the layer A,B and vegetation coverage, and the relationship between the contents of soil readily available P in the layer B and vegetation coverage is on the contrary.
2005 Vol. 3 (2): 15-22 [
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1542
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23
WANG Guo-Qiang-；Long-Hui-；Jing-Xin-Ai-；Li-Hao-Bing
Variation phases and its characteristics of hydrological regime of Qingjianhe River basin
The representative rainfall gauge stations were selected firstly according to quantitative indexes and qualitative principle. And then, rainfall series from 1955 to 2002 which has good consistency was established based on the selected rainfall gauge stations. Adopting moving average method and serial cluster analysis method, hydrological series in the basin was divided into three phases according to annual runoff coefficient variation. Finally, variation characteristics of precipitation and runoff in each phase and the possible reasons which may cause runoff variation were further analyzed based on practical situation of soil and water conservation measures in each phase. And the results show that three divided phases of hydrological series are 1955-1979, 1980-1989, and 1990-2002. Comparing with rainfall and runoff in the first phase, annual precipitation and rainfall in the flood season from June to September in the second and the third phases have presented decreasing trends. Although runoff in the second phase is less than that in the first phase, runoff in the third phase is greater than that in the first two phases. Annual runoff amount and annual precipitation in each phase have bad positive correlation relationship. Hydrological regimes are up to characteristics of storm pattern, quantity and quality of soil and water conservation measures.
2005 Vol. 3 (2): 23-27 [
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1482
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28
TUN Yong-Gong-；Wang-Yuan-Chang-；Liu-Bin-；Cao-Shu-Yang-；Wang-Zhi-Xiong
Soil erosion fluctuations of loess slope
137
Cs inventory fluctuations along the loess slopes under different land use in the Nanxiaohegou gully watershed of Xifeng are shown. By analysis of the fluctuations and of the results of erosion fluctuations on slopes from other studies, it is concluded that soil erosion intensity always fluctuates as slop length increases on loess slopes because of rill erosion variations along slopes. Soil erosion fluctuations on loess slopes can be divided into two types, cultivated slopes under strong influences of human activities and uncultivated slopes with little influences.
2005 Vol. 3 (2): 28-31 [
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1271
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32
DAN Qiong-；Zhang-Ceng-Xiang-；Zhang-Guo-Beng-；Zhou-Quan-Bin
DEM correction using TVDI to evaluate soil moisture status in China
The factors that affect the retrieval of soil moisture status using TVDI method are discussed. Considering the geographical characteristics in China, a method of correcting
t
s
with DEM before constructing ts-NDVI space is suggested. Measured topsoil moisture from around China is used to determine the parameter in the correction. Comparison between the TVDI obtained before and after the correction shows that the TVDI obtained after DEM correction can better reflect the spatial distribution of soil moisture in China.
2005 Vol. 3 (2): 32-36 [
Abstract
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1944
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37
GAO Zhi-Hai-；Li-Ceng-Yuan-；Ding-Guo-Dong-；Li-Lin-Yang
New approach for desertification assessment by remote sensing based upon Rain Use Efficiency of vegetation
A new approach suited to desertification by remote sensing monitoring for desertification assessment taking Rain Use Efficiency (RUE) of the vegetation as a key indicator is presented according to the results of many researches about change of RUE in desertification process, considering much of spatial scale and criterion of desertification assessment and the scaling characteristics of different potential indicators for desertification assessment. This kind of method can get over the shortcomings that the approaches taking the vegetation characters as main indicators are greatly influenced by the variation of annual rainfall. This new approach emphasizes the common characteristics of different types of desertification, so it can be applied in assessments of many types of desertification by remote sensing.
2005 Vol. 3 (2): 37-41 [
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2199
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42
HU Jian-Zhong-；Zheng-Jia-Li-；Zhang-Chun-Xia
Evaluation to composing, structure and function for soil and water conservation of vegetation in rehabilitated lands in upper reach of the Yellow River
For the severe situation of eco-unbalance in the upper reaches of the Yellow River, the study of function for soil and water conservation in rehabilitated lands not only has the theoretical values, but has the urgent need for practice. The more the species and layers, the higher the function of vegetation. The research in the high mountains of the upper reaches of the Yellow River, shows that the high species richness appears in the middle stage of vegetation succession with more plant layers (usually 3～5 layers) and complex species and genes, and result in more rain reception and good eco-functions. In the implement of the project of Conversion of Cropland to Forest and Grassland, more attention should be paid to rehabilitate mixed conifer (mainly
Picea crassifolia
)and broad leaved trees in the middle stage of succession than such climax communities. As the vegetations grow, their structures and functions increase gradually. Some artificial vegetation types after 20 odd years in the rehabilitated lands have more bio-diversity, complex vertical layers of community, with so good eco-functions that even surpassing some of native vegetation, and approaching to the best one of eco-function in the areas, namely, 50 odd years native mixed
Picea crassifolia
with broad leaved trees. In the process of PCCFG, it is pressing and feasible to realize the whole function of artificial vegetation in the rehabilitated lands by means of imitating native vegetation structure for restoration of mixed and complicated vegetation types.
2005 Vol. 3 (2): 42-50 [
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51
KANG Ling-Ling-；Bao-Hong-Zhe-；Liu-Li-Bin-；Wang-Yun-Zhang-；Wang-Jin-Hua
Analysis and confirm of the indexes of water storage and sediment trapping on the terrace of different type regions at the Loess Plateau
Terrace indexes of water storage and sediment trapping have been analyzed and confirmed according precipitation condition and terrace's quality in the loess hilly-gully region and loess gully region based on the promise and philosophy of the terrace index of water storage and sediment trapping, combing the physical circumstance of different typical region. The results showed that the index of water storage is larger in loess gully region than in other regions, and the storage benefit of high-class terrace in wet year, additionally, the variation amplitude of the water storage with variation precipitation in the region is higher, but the index of water storage in the second sub-region of the loess hilly-gully region is least. The maximum index of sediment trapping mostly appears in the first sub-region of the loess hilly-gully region and the second loess hilly-gully region, especially in all terrace in wet year or first and second terrace in normal year, which is 20～70t/hm
2
larger than other kinds. Index value of sediment trapping in loess hilly region is minimum among three regions.
2005 Vol. 3 (2): 51-56 [
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1575
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1320
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57
CHANG Dan-Dong-；Diao-Ming-Jun-；Wang-Li-Xian
Water reduction norm of soil and water conservation in Yellow River basin
Annual runoff amount of river basin is a significant basis of water resources evaluation and its allocation in reason, while water reduction norm of soil conservation is a foundation of estimating influences of soil and water conservation on annual runoff amount of river. On the basis of comprehensive analysis on present achievements of water reduction function and environment conservation regionalization of upper and middle reaches of Yellow River, adopting method of integrated management of small watershed, water reduction norms of soil and water conservation of regions are calculated, which are 245.5m
3
/hm
2
in loess hilly region, 118.5m
3
/hm
2
in loess plateau and hilly region and 471.9m
3
/hm
2
in earth-rocky mountainous region respectively. At last, reasonable approaches of inquiring into water reduction amount are probed into.
2005 Vol. 3 (2): 57-64 [
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1555
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65
DIAO An-Dong-；Wang-Bing-；Su-Tie-Cheng-；Bai-Xiu-Lan-；Li-Gang
Growth of different plant reclamation measures on plant growth and the effect on soil chemical properties in gangue waste land
To select tree species and reclamation measures suitable for gangue waster land, the effects of different reclamation measures on plant growth and soil chemical properties in gangue waste land were studied in Fushun of Liaoning province. The results showed that the survival rate of different plants ranged from 21% to 85%, in which that of
Ulmus pumila
and
Astragalus adsurgen
s was 81% and 85% respectively and that of
Populus simionii
,
Robinia pseudoacacia
and
Koelreuteria panaiculata
was about 70%. They were suitable to the gangue waste land environment. Vegetation can improve the contents of organic matter, total N, total P and total K in different soil layers, but the degree of improvement varied with soil layers and nutrient varieties. Biological compound fertilizers, biopreparate, water retention agent were utilized together which can improve the growth of the main tree species.
2005 Vol. 3 (2): 65-69 [
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1659
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1468
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70
YE Min-Sheng-；Guan-Wen-Ban-；Bai-Tie-Xiong-；Ma-Ke-Meng-；Liu-Guo-Hua-；Hong-Xi-Lin
Ecological gradient of plant community in the dry valley of Minjiang River
To provide scientific accordance for vegetation rehabilitation and biological diversity protection, quantitative analysis method-DCCA ordination was used to analyze the vegetation and environmental data to reveal the relationship of ecological gradient and the distribution of plant community in the dry valley of the Minjiang River. Then the relationship of ground biomass of different shrubs and environmental factors were studied using principal component analysis. The result of DCCA ordination showed that the distribution of vegetation in the region is affected synthetically by soil moisture, soil nutrient and micro-topography. Principal component analysis showed that soil pH value, readily available P, Total N, soil organic matter and aspect of slope as the first principal component had effects on ground biomass of shrubs. The second principal component mainly included soil moisture and altitude. The third and forth principal component mainly consisted of soil readily available K and slope gradient respectively. Ground biomass of main shrub is also affected synthetically by soil nutrient, soil moisture and topography.
2005 Vol. 3 (2): 70-75 [
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1843
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3551KB] (
1178
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76
FAN Jin-Quan-；Chen-Yuan-Guo
Soil moisture characteristics of walnut forest land in Weibei Loess Plateau
Water is a crucial limiting factor for the eco-environmental restoration and economic development in the Loess Plateau. That has practical and scientific significance to study the dynamic law of soil moisture. Based on random design and field experiments, the soil moisture condition and its changing law of walnut forest land were studied. The results showed that soil evaporative capacity of walnut forest land was positive correlation to average temperature of month. Precipitation, soil evaporation and plant transpiration were the primary factors affecting soil moisture which variation with time. The seasonal change of soil moisture in growing period of walnut was divided into three stages, excessive consume period in late spring and beginning summer (from May to June), supply period in rainy season (from July to October) and slow accumulation period in winter and spring (from November to April in next year). The seasonal change of soil moisture had closed correlation to seasonal change of precipitation. The water amount of soil in walnut forest is the highest in August and lowest in June. The water consume amount of which is the ighest in July and lowest in April. As to soil moisture profit and loss, it is in a deficient condition from April to July, and supplemented from August to October with rainfall increasing. Soil moisture could be improved and water scarcity could be decreased in a certain degree through water regulation. To amount of soil moisture consume, which was increased under different irrigation treatments, while decreased in a certain degree under covering membrane, covering grasses and pruning. In a word, the effects of covering membrane, covering grasses, pruning in a moderate level and irrigation (225?kg in April, 225?kg in June) were better than others. Especially the effect of covering membrane was the best, not only soil moisture was increased, the exhausting was increased and the growth of development was promoted, but also cost of which was cheap, gained easily and used expediently. It was suggested that the measure of covering membrane should be popularized in high yield cultivation of cash forest in loess plateau.
2005 Vol. 3 (2): 76-80 [
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1395
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81
LIU Shao-Chong-；Duan-Wen-Biao-；Diao-Yu-Sen
Water-holding capacity of litter layer for various major forest types in Lianhua Lake reservoir area
The litter amount and water-holding characteristic of litter layers have been studied in this paper for various major forest types （
Pinus koraiensis
,
Larix gmelinii
, and weed trees） and waste grassland in Lianhua Lake reservoir area. The results indicate that the litter amount of
Larix gmelinii
plantations,
Pinus koraiensis
plantations, weed trees and waste grassland is 20.8, 23.9, 16.4, 5.7?t/hm
2
, respectively, in which amount of coniferous forest is the largest. Their maximum water retention rates of litter layers are 278.2%, 295.3%, 260.3%, 154.8%, respectively. The general water absorption speed varies most rapidly in 3 hours after soaked in water, reaching saturated state in about 24 hours. The water-holding speed performs remarkable power function correlation with the soaked time. Their available interception rates are 53.87%, 65.95%, 54.50%, 53.45%, respectively. Their available interception amount variation is 31.20, 45.97, 23.27, 2.94?t/hm
2
, respectively. The result shows that the litter layers of
Pinus koraiensis
have the best water-holding capacity and the waste grassland has the worst in different vegetations in Lianhua Lake reservoir area.
2005 Vol. 3 (2): 81-86 [
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1453
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3441KB] (
1425
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87
LI Fa-Lin-；Huang-Tan-He-；Ca-Zhi-Fa-；Xie-Jin-Sheng
Annual variation of Longan litter fall and the annual flows on eroded slope orchard of Fujian
Seasonal dynamics and nutrient concentrations in litter fall and the annual flows of N, P, K, Ca and Mg were studied in Longan orchard systems on eroded slope orchard of Fujian. The result showed that annual litter fall of them were 48.153kg.The percentage of tree, leaf, branch, flower and fruit is 32.41%, 13.15%, 1.97% and 52.47% respectively. There is single litter fall peak in August and the amount is 29.115kg, amounting to 60.01% of whole year. Variation of N, P and K content is smaller than Ca and Mg content in leaf litter fall. The annual flows of N, P, K, Ca and Mg by litter fall were 697.91kg/hm
2
and its order is as follows: Ca>K>Mg>P>N（446.02>115.73>74.31>37.47>24.39, kg/hm
2
）. The orchard achieve cycles of them by leaf and fruit mainly. The concentrations of N, P and K in the leaves after falling are lower than mature leaves, because those elements transfer before leaf falling, but there are differences among three elements that Ca doesn't transfer in the leaves and the movement of Mg has differences in different months. Annual return amounts of N, P and K before the leaves falling is7.420, 6.374 and 53.152kg/hm
2
, the most return amounts of which is3.632, 3.762, and 21.920kg/hm
2
in September respectively.
2005 Vol. 3 (2): 87-91 [
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2125
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2761KB] (
1400
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92
HUANG Rong-Zhen-；Yang-Yu-Cheng-；Xie-Jin-Sheng-；Wang-Wei-Meng-；Zhang-Jin-Che
Properties of soil reservoir capacity in different forest land types in Minjiang River upper reaches of Fujian
Bare land is taken as CK and Schima superba,
Cunninghamia lanceolata
and enclosing & tending land as study objects, in order to study the mechanism of forest soil reservoir on storing and regulating run-off. The results show that total capacity in Schima superba,
Cunninghamia lanceolata
and enclosing & tending land was 503.95, 471.62 and 451.48?mm respectively, which was 1.23, 1.15 and 1.10 times as high as that in the CK; Storage capacity in them was 326.87, 332.21 and 309.94mm, 1.23, 1.25 and 1.17 times as high as that in the CK respectively; Dead capacity in them was 114.29, 89.60 and 101.46mm respectively, 1.11, 0.87 and 0.99 times as high as that in the CK; Flood control capacity in them was 62.79, 49.81 and 40.08mm, 1.52, 1.21 and 0.97 times as high as that in the CK respectively; and maximal available water capacity in them was 389.66, 382.02 and 350.02mm, 1.27, 1.251.14 times as high as that in the CK respectively. Capacities of forest soil reservoir in different forest lands follow the rule, storage capacity>dead capacity>flood control capacity. Comparison with CK, the increasing of capacities of forest soil reservoir correlates with the improvement of forest growing to land soil structure and better coverage in the forest land.
2005 Vol. 3 (2): 92-96 [
Abstract
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2201
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3555KB] (
1258
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97
TUN Fa-Qi-；Fan-Wen-Bei
Effects of soil encrustation on rainfall infiltration,runoff and sediment generation
Effects of soil encrustation and non-encrustation on rainfall infiltrating, runoff and sediment yield were studied under condition of 250 simulated rainfalls indoor and data of runoff and sediment accordingly. By comparison analysis, results showed that average infiltration rate of non-encrustation soil was 1.5 times as much as that of encrustation soil, and average total amount of sediment generation was 1.28 times as much as that of encrustation soil, but average total amount of runoff generation of encrustation soil was 1.15 times as much as that of non-encrustation soil. Therefore, soil encrustation had a function of slowing down rainfall infiltration, increasing surface runoff and restraining sediment generation. The weaker rainfall intensity, the bigger the function is, and the reverse is also true.
2005 Vol. 3 (2): 97-101 [
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1454
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1527
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102
RAO Liang-Yi-；Shu-Jin-Zhao
Advance of spatial allocation for protection forest
The spatial allocation for protection forest is the key technology as well as an important content of establishment of protection forest system. A review on the advance of spatial allocation for protection forest is made. Theoretic basis, methods and approaches for the research on the spatial allocation for protection forest are also elaborated. The ideas of the spatial allocation for protection forest are put forward and the future direction is set forth.
2005 Vol. 3 (2): 102-106 [
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1287
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3096KB] (
1428
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107
HAO Shi-Long-；Li-Bi-Cheng-；Diao-Xiao-Min-；Xu-Jiang
Dynamic analysis on the spatial pattern of landscape of small watershed in loess hilly-gully region:A case study of Shanghuang test area in Guyuan
In order to provide reference for reasonable use of land resource and regional sustainable development in loess plateau, taking Shanghuang test area as the study area, some landscape diversity indexes were attained under the support of GIS technology. Utilizing the indexes such as patch size and amount, average fractal dimension, patch extension index, diversity index, dominance, consistency degree and fragmentation, the dynamic changes of landscape diversity in the loess hilly-gully region during the past 10 years were analyzed. The results showed that the total number of patch increased by from 1995 to 2004, among which, slope farmland and crude grass land decrease by 19 and 12 respectively, the artificial grass land and terrace farmland increase by 15 and 9 respectively, the average area and perimeter of patches decrease by 0.14hm
2
and 185hm
2
separately, the patch fractal dimension of terrace, crude grass land, woodland, orchard and village decrease in different degrees, slope farmland, artificial grassland, shrub land and unutilized land increase slightly, the irrigable land, plain, arbor land and water area were kept up. The characteristics of landscape heterogeneity are depicted that the consistency degree and diversity index decrease by 5.86 and 0.25 respectively, while the fragmentation and dominance increase by 0.25 and 0.002 respectively. The degree of man-made interference increases by 1.95. The landscape ecosystem mainly composed of farmland and grass has already changed in to highly heterogeneous landscape ecosystem mainly composed of forest and gross. Human activity is the main driving factor for the dynamic changes of spatial pattern of landscape in this test area.
2005 Vol. 3 (2): 107-112 [
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1481
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3628KB] (
1111
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113
HAN Xiao-Zhuo-；Li-Zi-Zhen-；Zhang-Ke-Bin-；Li-Run-Jie-；Hui-Cang-；Gao-Meng
Ecological risk analysis and evaluation of water resources system:A case study of Xiangride oasis
Ecological risk analysis and its evaluation of water resources is a key problem of sustainable utilization of water resources, while that in oasis region of endorheic drainage is a hotspot. Taking water resources systems of Xiangride oasis in Qinghai as a research object, two models are established which reveal risk evaluation resulted from runoff amount uncertainty of water resources. The uncertainty of water resources and its influence on principal industries in oasis region are quantitatively analyzed. The results indicate that risk index because of runoff amount uncertainty of water resources is 0.362, that of protection forest net integrality is 0.289, and that of agricultural structure affected by water resources and protection forest synthetically is 0.294, whole ecological risk of water resources system is 0.2925.
2005 Vol. 3 (2): 113-118 [
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1575
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1229
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119
LIU Fu-De-；Jiang-Yue-Zhong-；Liu-Ya-Quan-；Wang-Hua-Tian-；Jiao-Xu-Juan-；Kong-Lian-Gang
Characteristics of soil enzymes activities in Ⅰ-107 (
Populus×Euramercana
'Neva') Poplar Nursery under continuous cropping
Effect of continuous cropping on the soil enzymes of Ⅰ-107 (
Populus×Euramercana
'Neva') poplar nursery was studied. The correlation between soil enzymes, soil nutrients and soil microbes were analyzed. Result showed that wth the planting generations added, activity of urease, catalase and peroxidase of 2nd and 3rd generation decreased by 7.84% and 33.26%, 1.56% and 10.94%, 16.25% and 21.15%, respectively. Compared with the 1st generation, with soil depth increasing, the activities of urease, catalase and peroxidase decreased steadily. But the polypHenol oxidase activity was high in topsoil and lower in deep soil. The correlation coefficients between urease and peroxidase, urease and catalase were significant at 0.05 and 0.01 level. Beside Zn, Mn and Fe, all the other mineral elements, such as available N, P and K and trace-element Cu in soil of 2nd and 3rd generations, were descending by 9.19% and 33.50%, 29.53% and 43.91%, 22.06% and 44.48%, 11.37% and 46.85%, respectively, comparied with 1st generation. Soil organic nutrient contents of 2nd and 3rd generations were decreasing by 15.05% and 29.61%, respectively. Beside polypHenol oxidase enzyme and trace-element Zn, Mn and Fe, correlation between soil enzymes and soil nutrients was significant at 0.05 or 0.01 levels. With the planting generation increasing, the quantity of the soil bacterium, fungi and actinomyces decreased steadily. Total microbe quantity in 2nd and 3rd generations decreased by 29.55% and 52.44%, respectively. Therefore soil bacterium, fungi and actinomyces quantity decreased by 30.10% and 51.88%, 19.91% and 68.39%, 20.17% and 57.18%, respectively. Correlation coefficients between urease and actinomyces, catalase and bacteria, actinomyces, total microbe quantity, peroxidase and fungi were significant at 0.05 levels, and correlation coefficients between catalase and fungi peroxidase and bacteria, total microbe quantity were significant at 0.01 level.
2005 Vol. 3 (2): 119-124 [
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1560
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1314
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125
BO Jian-Beng-；Jiao-Jun
Design technology of middle and small check dam for farmland forming with culvert-like spillway
To guarantee normal production, spending flood safely and sustainable use, check dam for farmland forming, it is necessary to build outlet works. Culvert and horizontal pipes and spillway with hatch control need management of person specially assigned when flood is discharged. Spillway with non-gate control can stand large quantity of flood, but need many funds, therefore not economical because of big size of section. In order to overcome disadvantages mention above, fixed culvert is designed instead of gate of spillway with hatch control. This can not only control flood discharge amount and protect farmland and road in the lower reaches, but also reach the purpose of making section size smaller and saving funds. According to largest quantity of free discharge and order of designing peak flow quantity in the flood discharge, flood regulation routing formula of general graph is computed.
2005 Vol. 3 (2): 125-128 [
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1486
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1396
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