Volume 18,Issue 4,2020 Table of Contents
2020, 18(4):1-7.
Abstract:
The evaluation index system for the Xing fu river is constructed consisting of 26 indicato rs including the natural attributes of the river basin, social and economic attributes, and the harmo nio us relationship between people and water. T he evaluation result of the Xing furiver is expressed by the Xing fu river index. According to the demand hierarchy theory , the Xingfu river index is divided into the basic demand level, the development demand level, and the harmonious demand level. Taking the Yellow River Basin as an example, the fuzzy comprehensive evaluation method is used to evaluate the Xingfu river index of the Yellow River. The results show that the Xingfu river index in the upstream and middle of the Yellow River reaches the intermediate level of demand and the downstream Xingfu river index is at the basic level of demand. The construction of the evaluation index system of the Xingfu river prov ides a reference for the scientific evaluation of the Xingfu river and enriches the theoret ical research of the Xingfu river.
The evaluation index system for the Xing fu river is constructed consisting of 26 indicato rs including the natural attributes of the river basin, social and economic attributes, and the harmo nio us relationship between people and water. T he evaluation result of the Xing furiver is expressed by the Xing fu river index. According to the demand hierarchy theory , the Xingfu river index is divided into the basic demand level, the development demand level, and the harmonious demand level. Taking the Yellow River Basin as an example, the fuzzy comprehensive evaluation method is used to evaluate the Xingfu river index of the Yellow River. The results show that the Xingfu river index in the upstream and middle of the Yellow River reaches the intermediate level of demand and the downstream Xingfu river index is at the basic level of demand. The construction of the evaluation index system of the Xingfu river prov ides a reference for the scientific evaluation of the Xingfu river and enriches the theoret ical research of the Xingfu river.
2020, 18(4):8-16.
Abstract:
To accurately calculate and evaluate the ecological flow of the Yellow River, six hydrological methods are used to analyze the process of ecological flow and the ecological flow deficit and its causes of formation from 1956 to 2013 in Jimai, Tang naihai, Guide, Lanzhou, Shizuishan, Longmen, Huayuankou, and Lijin stations. The results show that the ecological flow accounting is more sensitive to method select ion, among which the results of the Q 90_ Q 50 method are much higher compared to the other five methods. The ecological flow of 8 sections of the Yellow River is( 47± 9) , ( 273± 59) , ( 273 ± 53) , ( 456 ±103) , ( 433±94) , ( 473 ±124) , ( 639±172) and( 727 ±160) m3 / s, accounting for 36% ~ 43% o f the natural runoff, of w hich M ay to November accounts for 70% ~ 77% of the annual ecological flow. In the past 60 years, the most serious period of ecological flow deficit is from 1985 to 2003 in the mainstream of the Yellow River . The ecological flow deficit in Jimai, Tangnaihai, Guide, and Lanzhou sections mainly occurs in the dry season, while in Shizuishan, Longmen and Huayuankou sections mainly occur in the wet season, and L ijin section concentrated in the first half of the year. Human water consumption is the most important cause of ecological flow deficit, followed by climate change. In the future, it is necessary to comprehensively assess the ecolo gical flow ofthe mainstream and tributaries of the Yellow River with different methods, promote " accurate" water conservation, improve water reg ulation schemes, and minimize the risk of ecological flow deficit.
To accurately calculate and evaluate the ecological flow of the Yellow River, six hydrological methods are used to analyze the process of ecological flow and the ecological flow deficit and its causes of formation from 1956 to 2013 in Jimai, Tang naihai, Guide, Lanzhou, Shizuishan, Longmen, Huayuankou, and Lijin stations. The results show that the ecological flow accounting is more sensitive to method select ion, among which the results of the Q 90_ Q 50 method are much higher compared to the other five methods. The ecological flow of 8 sections of the Yellow River is( 47± 9) , ( 273± 59) , ( 273 ± 53) , ( 456 ±103) , ( 433±94) , ( 473 ±124) , ( 639±172) and( 727 ±160) m3 / s, accounting for 36% ~ 43% o f the natural runoff, of w hich M ay to November accounts for 70% ~ 77% of the annual ecological flow. In the past 60 years, the most serious period of ecological flow deficit is from 1985 to 2003 in the mainstream of the Yellow River . The ecological flow deficit in Jimai, Tangnaihai, Guide, and Lanzhou sections mainly occurs in the dry season, while in Shizuishan, Longmen and Huayuankou sections mainly occur in the wet season, and L ijin section concentrated in the first half of the year. Human water consumption is the most important cause of ecological flow deficit, followed by climate change. In the future, it is necessary to comprehensively assess the ecolo gical flow ofthe mainstream and tributaries of the Yellow River with different methods, promote " accurate" water conservation, improve water reg ulation schemes, and minimize the risk of ecological flow deficit.
2020, 18(4):17-38.
Abstract:
In order to analyze the internal characteristics and driving mechanism o f land use change, the spatial and temporal changes o f land use have been comprehensively examined based on the overall pattern of land use, the direction of land use transfer , the degree o f transfer, and the single dynamic degree of land use in the Kuye River Basin in the past 40 years. SPSS soft ware is used to systematically ex plain its driving mechanism. T he results showed that: T he proportions of different land types throughout the basin are grassland> farmland> coal mine land> forest land> sand land> residential land> water area> unused land, respectively; Farmland is lar ely gathered in the middle and southeast of the basin while coal mine land is mainly distributed along the riv er bank; In the research period, as the most dynamic type of land use, coal mine land had greatly increased its area, and its main inflow sources are grassland and farmland, and T he large scale exploitation of coal in this basin has seriously affected the vegetation cover and agricultural production activities in this basin; T he rapid economic development , especially the growth of the secondary and tertiary industries are the most important driving factor leading to obvious changes in the coal mine land and residential land in the basin, H ow ever the changes in farm land, forest land, grassland, and water area are also closely related to them, but the changes are relatively small; Besides, the population also plays a more obvious role in the process of land use change.
In order to analyze the internal characteristics and driving mechanism o f land use change, the spatial and temporal changes o f land use have been comprehensively examined based on the overall pattern of land use, the direction of land use transfer , the degree o f transfer, and the single dynamic degree of land use in the Kuye River Basin in the past 40 years. SPSS soft ware is used to systematically ex plain its driving mechanism. T he results showed that: T he proportions of different land types throughout the basin are grassland> farmland> coal mine land> forest land> sand land> residential land> water area> unused land, respectively; Farmland is lar ely gathered in the middle and southeast of the basin while coal mine land is mainly distributed along the riv er bank; In the research period, as the most dynamic type of land use, coal mine land had greatly increased its area, and its main inflow sources are grassland and farmland, and T he large scale exploitation of coal in this basin has seriously affected the vegetation cover and agricultural production activities in this basin; T he rapid economic development , especially the growth of the secondary and tertiary industries are the most important driving factor leading to obvious changes in the coal mine land and residential land in the basin, H ow ever the changes in farm land, forest land, grassland, and water area are also closely related to them, but the changes are relatively small; Besides, the population also plays a more obvious role in the process of land use change.
2020, 18(4):39-53.
Abstract:
Different datasets ( MODIS13Q1 NDVI, DEM, LULC, and meteorological data) were used to study the regional differences of the spatial distribution pattern of NDVI and hydrothermal conditions in the Yellow River Headwaters. The distribution pattern of vegetation and hydrothermal conditions and the correlation between NDVI and hydro thermal fact ors were analyzed and investig ated based on three elevation sections ( section I< 3 400 m, section II 3 400 m~ 4 200 m, section III> 4 200 m) , respectively. The results showed that the maintype of vegetation in the Yellow River Headwaters was grassland, which accounted for 75% of the to tal area. However, forest and farmland areas accounted for 7% and 1% , respectively. Farmland was mainly distributed in sect ion ? and the forest was mainly distributed in section ò , while grass grows in all three sections. The average NDVI of different vegetation types ranks in this order: forest, grassland, and farm land. Moreover, the temperature displayed a spatial distribution pattern of decline gradient, and the precipitation represented a declining trend from southeast to northwest. The three partitions have different hydrothermal conditions. Section I belonged to the arid region, section II belonged to the moistheat region, and section ó belonged to the dry region, respectively. Section ò had the relatively best hydrot hermal combination conditions, which was followed by section ? , while section ó had the worst of three partitions. The results also revealed that NDVI was driven by different hydrothermal factors indifferent sections. The main factor that affected the growth of vegetation in section I and ó was precipitation, while in section II, the temper ature is the main factor while the rainfall was abundant .
Different datasets ( MODIS13Q1 NDVI, DEM, LULC, and meteorological data) were used to study the regional differences of the spatial distribution pattern of NDVI and hydrothermal conditions in the Yellow River Headwaters. The distribution pattern of vegetation and hydrothermal conditions and the correlation between NDVI and hydro thermal fact ors were analyzed and investig ated based on three elevation sections ( section I< 3 400 m, section II 3 400 m~ 4 200 m, section III> 4 200 m) , respectively. The results showed that the maintype of vegetation in the Yellow River Headwaters was grassland, which accounted for 75% of the to tal area. However, forest and farmland areas accounted for 7% and 1% , respectively. Farmland was mainly distributed in sect ion ? and the forest was mainly distributed in section ò , while grass grows in all three sections. The average NDVI of different vegetation types ranks in this order: forest, grassland, and farm land. Moreover, the temperature displayed a spatial distribution pattern of decline gradient, and the precipitation represented a declining trend from southeast to northwest. The three partitions have different hydrothermal conditions. Section I belonged to the arid region, section II belonged to the moistheat region, and section ó belonged to the dry region, respectively. Section ò had the relatively best hydrot hermal combination conditions, which was followed by section ? , while section ó had the worst of three partitions. The results also revealed that NDVI was driven by different hydrothermal factors indifferent sections. The main factor that affected the growth of vegetation in section I and ó was precipitation, while in section II, the temper ature is the main factor while the rainfall was abundant .
HE Guohua
,
JIANG Shan
,
ZHAO Yong
,
WANG Jianhua
,
ZHU Yongnan
,
HE Fan
,
HAN Xinx ueqi
,
L I Haihong
2020, 18(4):54-70.
Abstract:
The energy consumption of China's social water cycle process and the water consumption of power production is analyzed by taking provincial administ rative regions as the research o bject and year 2017 as the research period. The results show ed that : The total power consumption of Chinacs social water cycle process is 1 0821.81 billion kW· h, accounting for 171 2% of the total power consumption of China's society in 2017; Terminal water consumption is the biggest energy consumption. In 2017, Chinacs electricity production is consumed 6.57 billion m3 of water, accounting for 2% of the total social water consumption; and Thermal power is the most water consuming power source in China, accounting for 78% of the total water consumption in the countrycs electric power development. Based on the calculated results, relevant suggestions are put forword for realizing energy water coordinated security
The energy consumption of China's social water cycle process and the water consumption of power production is analyzed by taking provincial administ rative regions as the research o bject and year 2017 as the research period. The results show ed that : The total power consumption of Chinacs social water cycle process is 1 0821.81 billion kW· h, accounting for 171 2% of the total power consumption of China's society in 2017; Terminal water consumption is the biggest energy consumption. In 2017, Chinacs electricity production is consumed 6.57 billion m3 of water, accounting for 2% of the total social water consumption; and Thermal power is the most water consuming power source in China, accounting for 78% of the total water consumption in the countrycs electric power development. Based on the calculated results, relevant suggestions are put forword for realizing energy water coordinated security
2020, 18(4):71-80.
Abstract:
In view of the nonlinear problem of temperatur evegetation drought index, the MODIS data in the Hebei Province are studied to improve the accuracy of nonlinear fitting of dry and wet edges in traditional TVDI feature space by introducing the appar ent thermal inertia model and a double-index combined soil water content inversion model. The TVDI and DICIM indices are used to inv ert the soil water content in early and mid-June, respectively . The spatial differences of soil water content inversion in low v egetation areas are compared, while the modelcs inversion ability is verified by error statistics. The result shows that in the low vegetation area, the feature of DICIM inversion is more obvious than TVDI, and the inversion value is closer to the measured value. Besides, according to error statistics, the mean absolute error of DICIM is 0.26% to 0.50% lower than that of TVDI for the inversion value of soil water content at a depth of 10 cm . The root mean square error is 0.28 % to 0.73% lower than that of TVDI, the relative root mean square error is 0.73% to 5.54 % lower than that of TVDI, and the averager elative error is 1.31% to 3.27 % lower than that of TVDI, respectively . The correlation coefficient R values based on the DICIM inversion value and the measured soil moisture content at a depth of 10 cm is approximately 0.65. It can be seen that the proposed DICIM model combines the advantages of the ATI and TVDI models and improves the inversion ability of the traditional TVDI model.
In view of the nonlinear problem of temperatur evegetation drought index, the MODIS data in the Hebei Province are studied to improve the accuracy of nonlinear fitting of dry and wet edges in traditional TVDI feature space by introducing the appar ent thermal inertia model and a double-index combined soil water content inversion model. The TVDI and DICIM indices are used to inv ert the soil water content in early and mid-June, respectively . The spatial differences of soil water content inversion in low v egetation areas are compared, while the modelcs inversion ability is verified by error statistics. The result shows that in the low vegetation area, the feature of DICIM inversion is more obvious than TVDI, and the inversion value is closer to the measured value. Besides, according to error statistics, the mean absolute error of DICIM is 0.26% to 0.50% lower than that of TVDI for the inversion value of soil water content at a depth of 10 cm . The root mean square error is 0.28 % to 0.73% lower than that of TVDI, the relative root mean square error is 0.73% to 5.54 % lower than that of TVDI, and the averager elative error is 1.31% to 3.27 % lower than that of TVDI, respectively . The correlation coefficient R values based on the DICIM inversion value and the measured soil moisture content at a depth of 10 cm is approximately 0.65. It can be seen that the proposed DICIM model combines the advantages of the ATI and TVDI models and improves the inversion ability of the traditional TVDI model.
2020, 18(4):81-86.
Abstract:
Xin’anjiang model, Sacramento model and TOPMODEL were applied in three small watersheds of humid areas of China. The relative error of flood peaks and error of the time of flood peaks were taken as the evaluation indexes for assessing the forecasting accuracy , and applicability of different hydrological models indifferent basins. The results showed that: In Nanyanghe watershed. the Xin’anjiang Model had the better Prediction accuracy than the other two Models, and none of these three modals had high accuracy ; In Wuduhe w atershed, the Xin’anjiang model had the highest prediction accuracy , which meet the prediction accuracy requirements, and the Sacr amento model had moderate, while the TOPMODEL model had the worst accuracy ; In Mao ping he watershed, Xin’anjiang model had the hig hest prediction accuracy, while the Sacramento model and TOPMODEL model had slightly lower prediction accuracy than Xin’anjiang model, but these three models meet the prediction accuracy requirement. After a comprehensive comparison, it was found that Xin’anjiang mo del had the highest prediction accuracy in the three selected watersheds.
Xin’anjiang model, Sacramento model and TOPMODEL were applied in three small watersheds of humid areas of China. The relative error of flood peaks and error of the time of flood peaks were taken as the evaluation indexes for assessing the forecasting accuracy , and applicability of different hydrological models indifferent basins. The results showed that: In Nanyanghe watershed. the Xin’anjiang Model had the better Prediction accuracy than the other two Models, and none of these three modals had high accuracy ; In Wuduhe w atershed, the Xin’anjiang model had the highest prediction accuracy , which meet the prediction accuracy requirements, and the Sacr amento model had moderate, while the TOPMODEL model had the worst accuracy ; In Mao ping he watershed, Xin’anjiang model had the hig hest prediction accuracy, while the Sacramento model and TOPMODEL model had slightly lower prediction accuracy than Xin’anjiang model, but these three models meet the prediction accuracy requirement. After a comprehensive comparison, it was found that Xin’anjiang mo del had the highest prediction accuracy in the three selected watersheds.
2020, 18(4):87-96.
Abstract:
The impervious surface distribution is explored through field investigation, remote sensing interpretation and marking in the main ur ban area of Jinan. The study is revealed that the greening rate in the main urban area of Jinan reached 33.9% , and the proportion of the impervious area is 65.3% , respectively. The HIMS2SWMM model is used to simulate the hourly scale run-off, and the variation of t he runoff coefficient under the impervious surface distribution of each administrative district in the main urban area of Jinan City . Taking the rainfall from July to August 2016 as input, the whole study area has total precipitation of 125.23 mm, the infiltr ation amount is 36.33 mm, and the generated runoff is 88.9 mm, respectively . The overall runoff coefficient of the main urban area of Jinan is 0.71. The proportion of the impervious surface of each land type has a strong linearrelationship with the runoff coefficient, and the change is divided into threshold type and gradual type. For the threshold type of land use, more concentrated greening measures or LID measures can be carried out. For the gradual type of land use, slow gradual greening or LID measures can be adopted, which can improve the proportion of impervious water surface of the threshold type of land use in a cent ralized way , supplemented by a smaller range of improvement measures, aiming to achieve more economical and effective prevention of city floods.
The impervious surface distribution is explored through field investigation, remote sensing interpretation and marking in the main ur ban area of Jinan. The study is revealed that the greening rate in the main urban area of Jinan reached 33.9% , and the proportion of the impervious area is 65.3% , respectively. The HIMS2SWMM model is used to simulate the hourly scale run-off, and the variation of t he runoff coefficient under the impervious surface distribution of each administrative district in the main urban area of Jinan City . Taking the rainfall from July to August 2016 as input, the whole study area has total precipitation of 125.23 mm, the infiltr ation amount is 36.33 mm, and the generated runoff is 88.9 mm, respectively . The overall runoff coefficient of the main urban area of Jinan is 0.71. The proportion of the impervious surface of each land type has a strong linearrelationship with the runoff coefficient, and the change is divided into threshold type and gradual type. For the threshold type of land use, more concentrated greening measures or LID measures can be carried out. For the gradual type of land use, slow gradual greening or LID measures can be adopted, which can improve the proportion of impervious water surface of the threshold type of land use in a cent ralized way , supplemented by a smaller range of improvement measures, aiming to achieve more economical and effective prevention of city floods.
2020, 18(4):97-103.
Abstract:
Evapotranspiration can reflect the impact of climate change on water resources. Based on the daily weather data from 1955 to 2018 at two sites in the Lhasa River Basin, the potential evapotranspiration ( ET0 ) was calculated using the FAO-56-Penman-Monteith formula. The sensitivity analysis, Mann-Kendall trend test , climatic tendency rate, and wavelet analysis were used to analyze the variation law of ET0 in the Lhasa River Basin and its influencing factors. Comparing the changes changing characteristics of of the two stations, the results show that : The whole basin ET0 is the most sensitive to the highest temperature, and the contribution of highest temperature contribution to ET0 was the largest. The sensitivity coefficient of meteorological factors varies vary within the year: relative humidity> max imum temperature> wind speed> sunshine hours> minimum temperature, respectively ; The daily variation trend of ET0 in the basin is was 0.03 mm per 10 years and the increase of ET0 in the watershed by Mann-Kendall was not significant; The ET0 of the basin has a cyclical oscillation on the 25-30 year scale, and there are were obviously 7 cycles of alternating
Evapotranspiration can reflect the impact of climate change on water resources. Based on the daily weather data from 1955 to 2018 at two sites in the Lhasa River Basin, the potential evapotranspiration ( ET0 ) was calculated using the FAO-56-Penman-Monteith formula. The sensitivity analysis, Mann-Kendall trend test , climatic tendency rate, and wavelet analysis were used to analyze the variation law of ET0 in the Lhasa River Basin and its influencing factors. Comparing the changes changing characteristics of of the two stations, the results show that : The whole basin ET0 is the most sensitive to the highest temperature, and the contribution of highest temperature contribution to ET0 was the largest. The sensitivity coefficient of meteorological factors varies vary within the year: relative humidity> max imum temperature> wind speed> sunshine hours> minimum temperature, respectively ; The daily variation trend of ET0 in the basin is was 0.03 mm per 10 years and the increase of ET0 in the watershed by Mann-Kendall was not significant; The ET0 of the basin has a cyclical oscillation on the 25-30 year scale, and there are were obviously 7 cycles of alternating
2020, 18(4):104-110.
Abstract:
Assessment of water quality by firefly algorithm based on BP neural network model ( FA-BP model) is built. In this model, the ev aluation index function is constructed by BP Artificial Neural Network Algorithm ( BP model) , and Firefly Algorithm ( FA model) is intr oduced to optimize weight values and thresholds to find the optimal solution. Fuzzy Comprehensive Evaluation method, Grey Incidence Analysis Algorithm and FA-BP model will be applied to evaluate the water quality of the five main rivers in Liany ungang City including Longwei, Yudai, Dapu, Paidan, and Dong yan River. The results show that the Fuzzy Comprehensive Evaluation method is difficult to use for slight pollution rivers with several slightly over standard indexes. It will be easy to ignore the impact of ex treme indexes by Grey Incidence Analysis Algorithm. FA-BP model solves the shortcomings of the two methods. The evaluation results pr ovide an important reference for the formulation of reasonable measures. It is a relatively comprehensive evaluation method and has agood a pplication prospect in water qualit yevaluation.
Assessment of water quality by firefly algorithm based on BP neural network model ( FA-BP model) is built. In this model, the ev aluation index function is constructed by BP Artificial Neural Network Algorithm ( BP model) , and Firefly Algorithm ( FA model) is intr oduced to optimize weight values and thresholds to find the optimal solution. Fuzzy Comprehensive Evaluation method, Grey Incidence Analysis Algorithm and FA-BP model will be applied to evaluate the water quality of the five main rivers in Liany ungang City including Longwei, Yudai, Dapu, Paidan, and Dong yan River. The results show that the Fuzzy Comprehensive Evaluation method is difficult to use for slight pollution rivers with several slightly over standard indexes. It will be easy to ignore the impact of ex treme indexes by Grey Incidence Analysis Algorithm. FA-BP model solves the shortcomings of the two methods. The evaluation results pr ovide an important reference for the formulation of reasonable measures. It is a relatively comprehensive evaluation method and has agood a pplication prospect in water qualit yevaluation.
2020, 18(4):111-120.
Abstract:
With the gradual attention of the state to the protection of natural ecological environment, the planning and layout of the nature reserve will overlap with some coal mine areas. In order to strengthen the construction of ecological civilization, it is necessary to study the impact of mining on the ecological environment of the nature reserve. Through the methods of GIS and RS, and evaluation o f ecological protection index system, the differences and impacts of ecological environment changes before and after the planning of the nature reserve are analyzed. The results show that since 2002, the effect of water collection and artificial soil and water conservation measures on improving the ecological environment of vegetation are obvious, the dominant species of vegetation type in the overlapping area of coal mine and nature reserve have changed from grass vegetation to shrub vegetation, inwhich the area of arbor forest land has increased significantly, the veetationcoverage in the overlapping area has also increased considerably . The intensity of soil erosion has decreased year by year after mining the coal resources. Postharvest hydraulic erosion intensity is mainly below mild, and the area of artificial soil and water conservation has increased significantly. T he negative impact of the ground subsidence caused by coal mining on the ecological environment is less than the positive effect brought by artificial soil and waterconservation measures, and it is generally developing in a more stable direction. The ecological protection status index increased fr om 32. 98 to 45.94, and the change degree of ecological protection status in nature reserves is 12.9 ≥10. T he ecological protection status of the nature reserve improved significantly. On the basis of ecological environment protection and restoration measures in the nature reserve, coal mines need to further study the comprehensive impact of human activitieson the ecological environment of the nature reserve.
With the gradual attention of the state to the protection of natural ecological environment, the planning and layout of the nature reserve will overlap with some coal mine areas. In order to strengthen the construction of ecological civilization, it is necessary to study the impact of mining on the ecological environment of the nature reserve. Through the methods of GIS and RS, and evaluation o f ecological protection index system, the differences and impacts of ecological environment changes before and after the planning of the nature reserve are analyzed. The results show that since 2002, the effect of water collection and artificial soil and water conservation measures on improving the ecological environment of vegetation are obvious, the dominant species of vegetation type in the overlapping area of coal mine and nature reserve have changed from grass vegetation to shrub vegetation, inwhich the area of arbor forest land has increased significantly, the veetationcoverage in the overlapping area has also increased considerably . The intensity of soil erosion has decreased year by year after mining the coal resources. Postharvest hydraulic erosion intensity is mainly below mild, and the area of artificial soil and water conservation has increased significantly. T he negative impact of the ground subsidence caused by coal mining on the ecological environment is less than the positive effect brought by artificial soil and waterconservation measures, and it is generally developing in a more stable direction. The ecological protection status index increased fr om 32. 98 to 45.94, and the change degree of ecological protection status in nature reserves is 12.9 ≥10. T he ecological protection status of the nature reserve improved significantly. On the basis of ecological environment protection and restoration measures in the nature reserve, coal mines need to further study the comprehensive impact of human activitieson the ecological environment of the nature reserve.
2020, 18(4):121-129.
Abstract:
The object-oriented classification method is uttlized for Landsat remote sensing imagery and obtain spatial distribution maps of lakes in Jilin Province during the 30 years ( from 1985 to 2015) . The temporal and spatial dynamic characteristics of lake evolution are sy stematically analyzed using GIS through time dynamic index, spatial distribution vector density index, and multiple landscape indexes. The results show that: The area of lakes in Jilin Province showed a shrinking trend in 30 years. The area has decreased from 2 667. 12 km2 to 2 131. 25 km2, respectively. The number of lakes has decreased by 72, with a reduction ratio of 13. 74% . Lake resources in Jilin Province are mainly small lakes ( θ< 10 km2 ) , accounting for more than 90% . The number of lakes in different sizes has decr eased in 30 years, of which 63 small lakes have decr eased, accounting for 13.04% . The spatial distribution vector density shows that the distribution of lake resources in Jilin Province presents different characteristics in different regions. The lake resources in the east are scarce and have the lowest density index . The number of lakes has increased by 10.39% , but the total area has decreased by 10. 83 km2 . The lake resources in the west are rich and mainly small lakes. The number and area of lakes in 30 years have decreased significantly. The ar ea has decreased by 266. 85 km2 and the number has decreased by 25. 54% , respectively. The lake resources in the central region fluctuate greatly. The area has decreased by 237.75 km2 and the number has decreased by 5.33% .
The object-oriented classification method is uttlized for Landsat remote sensing imagery and obtain spatial distribution maps of lakes in Jilin Province during the 30 years ( from 1985 to 2015) . The temporal and spatial dynamic characteristics of lake evolution are sy stematically analyzed using GIS through time dynamic index, spatial distribution vector density index, and multiple landscape indexes. The results show that: The area of lakes in Jilin Province showed a shrinking trend in 30 years. The area has decreased from 2 667. 12 km2 to 2 131. 25 km2, respectively. The number of lakes has decreased by 72, with a reduction ratio of 13. 74% . Lake resources in Jilin Province are mainly small lakes ( θ< 10 km2 ) , accounting for more than 90% . The number of lakes in different sizes has decr eased in 30 years, of which 63 small lakes have decr eased, accounting for 13.04% . The spatial distribution vector density shows that the distribution of lake resources in Jilin Province presents different characteristics in different regions. The lake resources in the east are scarce and have the lowest density index . The number of lakes has increased by 10.39% , but the total area has decreased by 10. 83 km2 . The lake resources in the west are rich and mainly small lakes. The number and area of lakes in 30 years have decreased significantly. The ar ea has decreased by 266. 85 km2 and the number has decreased by 25. 54% , respectively. The lake resources in the central region fluctuate greatly. The area has decreased by 237.75 km2 and the number has decreased by 5.33% .
13 Hydrochemical characteristics of groundwater and its influencing factors in Dawu karst water source
2020, 18(4):130-140.
Abstract:
Karst aquifer medium is usually inhomogeneous, and hydrogeological parameters are hard to obtain. Using a multivariate statistical method, graphic method, ions ratio method combined with karst hydrogeological conditions is an important tool to study hydrogeo chemical evolution and its influencing factors. Atypical karst water source in North China was selected to examine its hydrochemical characteristics and its influencing factors using hydrog eochemical technologies and statistical methods. Along the groundwater flow path, the types of hydrochemistry were increasing year by year. In addition to the role of water and rock, Ca2+ , Cl- , Na+ and SO4 2- multisource domestic sewage, industrial wastewater and domestic garbage affect the hydrochemistry types. The detection of volatile org anic compounds ( VOCs) and the different recharging features of NO3 - , VOCs spatiotemporal indicated that the groundwater hydro chemistry is continuously affected by anthropogenic activities. The main processes influencing groundwater environment in the study ar ea were water-rock interaction, cation exchange and adsorption, lixiviation, and human activities, which can be interpreted by ion r atio, correlation analysis, factor analysis and wastewater sources of groundwater sampling points, dynamic variation processes of gro undwater chemistries and their influencing factors.
Karst aquifer medium is usually inhomogeneous, and hydrogeological parameters are hard to obtain. Using a multivariate statistical method, graphic method, ions ratio method combined with karst hydrogeological conditions is an important tool to study hydrogeo chemical evolution and its influencing factors. Atypical karst water source in North China was selected to examine its hydrochemical characteristics and its influencing factors using hydrog eochemical technologies and statistical methods. Along the groundwater flow path, the types of hydrochemistry were increasing year by year. In addition to the role of water and rock, Ca2+ , Cl- , Na+ and SO4 2- multisource domestic sewage, industrial wastewater and domestic garbage affect the hydrochemistry types. The detection of volatile org anic compounds ( VOCs) and the different recharging features of NO3 - , VOCs spatiotemporal indicated that the groundwater hydro chemistry is continuously affected by anthropogenic activities. The main processes influencing groundwater environment in the study ar ea were water-rock interaction, cation exchange and adsorption, lixiviation, and human activities, which can be interpreted by ion r atio, correlation analysis, factor analysis and wastewater sources of groundwater sampling points, dynamic variation processes of gro undwater chemistries and their influencing factors.
2020, 18(4):141-146.
Abstract:
The basic characteristics, formation, and evolution process of the large-scale accumulations developed in Yanluo Village , Yanmen Tow nship, Wenchuan County are studied based on detail field investig ations. The results show that: Yanluo depos it is a complex origin deposit that made up of residual and slope deposit, colluvium, loess like and landslide deposit , and it can be divided into two zones and six sub-zones; the failure modes of the evolution process of Yanluo depo sit are " bend-crack" which is simulated by UDEC so ftware; The 4 evolution phases of Yanluo deposit may be summarized as loess accumulation stage in early Pleistocene, unloading and deformation stage in middle-late Pleistocene, landslide formation stage, deposit reactivated and defo rmation stage in Holocene, respectively
The basic characteristics, formation, and evolution process of the large-scale accumulations developed in Yanluo Village , Yanmen Tow nship, Wenchuan County are studied based on detail field investig ations. The results show that: Yanluo depos it is a complex origin deposit that made up of residual and slope deposit, colluvium, loess like and landslide deposit , and it can be divided into two zones and six sub-zones; the failure modes of the evolution process of Yanluo depo sit are " bend-crack" which is simulated by UDEC so ftware; The 4 evolution phases of Yanluo deposit may be summarized as loess accumulation stage in early Pleistocene, unloading and deformation stage in middle-late Pleistocene, landslide formation stage, deposit reactivated and defo rmation stage in Holocene, respectively
2020, 18(4):149-158.
Abstract:
The influence of the lateral boundary conditions on the hydrody namic field of the vertical circulation well is focused on. T he mathem atical model and analytical solution under the existing lateral unbounded conditions are analyzed. Based on MODFLOW, the num erical model under the condition of lateral boundedness is established, which simulates the multiple sets of different pum ping flow and sam pling intervals. The error distribution map, the forward trace stream line diag ram and the groundwater flow r atio map show the influence of the lateral boundary on the head, streamline morphology and flow ratio , respectively. The re sults show that: with the increase of flow rate and the spacing of the pumping section, the circulation range of the hydrodynam ic field of the vertical circulation well increases, the influence of the boundary on the hydrodynamic field of the vertical circulation well is gradually obvious, the flow line is closer to the lateral boundary, the shape is close to a rectangle by an ellipse, and the proportion of groundwater exchange in the outermost equilibrium zone is reduced. The influence of the lateral boundary on the flow field is further analyzed quant itatively by proposing dimensionless parameters.
The influence of the lateral boundary conditions on the hydrody namic field of the vertical circulation well is focused on. T he mathem atical model and analytical solution under the existing lateral unbounded conditions are analyzed. Based on MODFLOW, the num erical model under the condition of lateral boundedness is established, which simulates the multiple sets of different pum ping flow and sam pling intervals. The error distribution map, the forward trace stream line diag ram and the groundwater flow r atio map show the influence of the lateral boundary on the head, streamline morphology and flow ratio , respectively. The re sults show that: with the increase of flow rate and the spacing of the pumping section, the circulation range of the hydrodynam ic field of the vertical circulation well increases, the influence of the boundary on the hydrodynamic field of the vertical circulation well is gradually obvious, the flow line is closer to the lateral boundary, the shape is close to a rectangle by an ellipse, and the proportion of groundwater exchange in the outermost equilibrium zone is reduced. The influence of the lateral boundary on the flow field is further analyzed quant itatively by proposing dimensionless parameters.
16 Time-varying characteristics and factors analysis of the valley area of Jinping I Hydropower Station
2020, 18(4):159-166.
Abstract:
Jinping I Hydropower Station is a world’s highest double-curved arch dam. In order to ensure the safe operation of the dam body, the deformation of the valley area was taken as a research objective. The telescopic deformation characteristics and main influencing factors of valley amplitude in the early excavation stag e, the initial water storage stag e and the long-term water storage stage were analyzed. T he current research indicated that in the early stag e o f excavation, the g rain width was in the shrinkage deformation during the accelerated period. The deformation rate w as about - 01 65 mm/ m, while the deformation amount w as 40 mm, respectively. In t he initial stage of w at er storage, the shrinkage deformation rate of the g rain width was about - 0. 5 mm/ m, and the deformation rate had a tendency to decrease. During the long-term water storage stage, the storage area in the reservoir area had ex perienced four cycles between 1 880 m-1 800 m-1 880 m. During the first two periods of the variation characteristics, the deformation o f the v alley area show ed a certain hysteresis characteristic to the change of water level. With the increase of waterstorage time, the grain width gradually and experienced a slight shrinkage stretching phenomenon, while the overall deformation value did not greatly change. Preliminary analysis of the main influencing factors o f g rain deformation could be found that the deformat ion of the grain in t he early excavation stage was mainly caused by the unloading rebound after ex cavation. In the later stage of water storage, the valley amplitude telescopic deformation was mainly caused by the structural deformation of the left bank slope.
Jinping I Hydropower Station is a world’s highest double-curved arch dam. In order to ensure the safe operation of the dam body, the deformation of the valley area was taken as a research objective. The telescopic deformation characteristics and main influencing factors of valley amplitude in the early excavation stag e, the initial water storage stag e and the long-term water storage stage were analyzed. T he current research indicated that in the early stag e o f excavation, the g rain width was in the shrinkage deformation during the accelerated period. The deformation rate w as about - 01 65 mm/ m, while the deformation amount w as 40 mm, respectively. In t he initial stage of w at er storage, the shrinkage deformation rate of the g rain width was about - 0. 5 mm/ m, and the deformation rate had a tendency to decrease. During the long-term water storage stage, the storage area in the reservoir area had ex perienced four cycles between 1 880 m-1 800 m-1 880 m. During the first two periods of the variation characteristics, the deformation o f the v alley area show ed a certain hysteresis characteristic to the change of water level. With the increase of waterstorage time, the grain width gradually and experienced a slight shrinkage stretching phenomenon, while the overall deformation value did not greatly change. Preliminary analysis of the main influencing factors o f g rain deformation could be found that the deformat ion of the grain in t he early excavation stage was mainly caused by the unloading rebound after ex cavation. In the later stage of water storage, the valley amplitude telescopic deformation was mainly caused by the structural deformation of the left bank slope.
2020, 18(4):167-177.
Abstract:
The spatial distribution characteristics of environmental isotopes and hydrochemistry in the regional groundwater were analyzed based on the analysis of geological and hydrogeological conditions, combined with the results of hydrochemistry , D, 18 O, 3 H, 14 C and CFCs of 220 sets of surface water and groundwater samples collected in 2017 and 2018 at the western plain of the Yili River and two typical sections in the north and south banks of Yili River Valley. Groundwater in the western plain of Yili River Valley was mainly supplied by precipitation from mountain areas. The change of to pography , geomorphology and aquifer structure was the most important factor to control groundwater circulation. The groundwater circulation showed multi-level cyclic evolut ion char acteristics. The groundwater flow systems on the north and south sides of the western plain of Yili River Valley can be divided into local, intermediate and regional groundwater flow systems. There are some differences in the circulation range and depth of different groundwater flow systems
The spatial distribution characteristics of environmental isotopes and hydrochemistry in the regional groundwater were analyzed based on the analysis of geological and hydrogeological conditions, combined with the results of hydrochemistry , D, 18 O, 3 H, 14 C and CFCs of 220 sets of surface water and groundwater samples collected in 2017 and 2018 at the western plain of the Yili River and two typical sections in the north and south banks of Yili River Valley. Groundwater in the western plain of Yili River Valley was mainly supplied by precipitation from mountain areas. The change of to pography , geomorphology and aquifer structure was the most important factor to control groundwater circulation. The groundwater circulation showed multi-level cyclic evolut ion char acteristics. The groundwater flow systems on the north and south sides of the western plain of Yili River Valley can be divided into local, intermediate and regional groundwater flow systems. There are some differences in the circulation range and depth of different groundwater flow systems
2020, 18(4):178-184.
Abstract:
In order to explore the relationship between carbon balance of farmland ecosystem under waterlogging stress, a typical test area was set up in Wudaogou experimental station, and the winter wheat jointing stage was used as the research period to carry out the control experiments. The surface/ subsurface waterlogging test and the normal test were set to measure and analyze the changing trend of the carbon flux under different conditions. T he results show that: under normal conditions, the carbon flux of winter wheat in the jointing stage is carbon sink, with the lowest carbon flux is at 13 o’clock, the carbon flux on a sunny day is lower than that on a rainy day, the carbon flux o n a sunny day after continuous rainy days is reduced, the waterlogging co ndition can reduce the carbon flux of winter wheat in the jointing stage, the influence of the surface waterlogging condition is more obvious, and the effect of the water logging condition on the winter wheat carbon flux after the third day is significantly weakened. Moreover, the temperature is another important factor affecting the carbon flux of winter wheat in the jointing stage.T he carbon flux changes with the temperature in cubic curves. Under normal and waterlogging scenarios, the carbon flux of winter wheat reaches the highest point around 7 ℃ . In the case of surface waterlogging , it reaches the highest point around 5 ℃ . T he results of the research can provide scientific evidence for keeping the carbon balance of farmland ecosystems and constructing the ecological irrigated areas.
In order to explore the relationship between carbon balance of farmland ecosystem under waterlogging stress, a typical test area was set up in Wudaogou experimental station, and the winter wheat jointing stage was used as the research period to carry out the control experiments. The surface/ subsurface waterlogging test and the normal test were set to measure and analyze the changing trend of the carbon flux under different conditions. T he results show that: under normal conditions, the carbon flux of winter wheat in the jointing stage is carbon sink, with the lowest carbon flux is at 13 o’clock, the carbon flux on a sunny day is lower than that on a rainy day, the carbon flux o n a sunny day after continuous rainy days is reduced, the waterlogging co ndition can reduce the carbon flux of winter wheat in the jointing stage, the influence of the surface waterlogging condition is more obvious, and the effect of the water logging condition on the winter wheat carbon flux after the third day is significantly weakened. Moreover, the temperature is another important factor affecting the carbon flux of winter wheat in the jointing stage.T he carbon flux changes with the temperature in cubic curves. Under normal and waterlogging scenarios, the carbon flux of winter wheat reaches the highest point around 7 ℃ . In the case of surface waterlogging , it reaches the highest point around 5 ℃ . T he results of the research can provide scientific evidence for keeping the carbon balance of farmland ecosystems and constructing the ecological irrigated areas.
2020, 18(4):185-194.
Abstract:
The data of five typical counties in Hebei Plain were collected to analyses the irrigation water requirement characteristics o f the wheat-maize continuous cropping system. Crop effective precipitation was calculated based on a modified SCS-CN model using precipitation, soil, crop conditions, among other factors. Crop water requirement was estimated by the Penman Monteith equation and crop coefficient method recommended by FAO . Besides, the spatial and temporal distribution characteristics of irrigation water requirements in different hydrological years were also analyzed. The results showed that the crop effective precipitation, water requirement and irrigation water requirement for the whole growing period of wheat-maize continuous cropping were 389, 736 and 347 mm, respectively, in the study area. T he ir rig atio n water requirement of wheat-maize continuouscropping in the wet , median, and dry water year was 321, 382 and 423 mm, respectively. The irrigation water requirement of winter wheat was 271-350 mm. The irrigation water requirement of the whole growth period was 26% , 26% and 29% respectively, in the period of turning green to jointing, jointing to heading and heading to maturity . The irrigation water requirement of summer maize was 0-49 mm accounting for 52% and 48% of the total fertility period, respectively. The spatial distribution of crop effective precipitation was decreased slowly from west to east in Shijiazhuang and increased gradually from west to east in Handan. T he water requirement in three counties of Shijiazhuang was slightly higher than those in two counties of Handan. The irrigation water requirement had a zonal distribution in the study area.
The data of five typical counties in Hebei Plain were collected to analyses the irrigation water requirement characteristics o f the wheat-maize continuous cropping system. Crop effective precipitation was calculated based on a modified SCS-CN model using precipitation, soil, crop conditions, among other factors. Crop water requirement was estimated by the Penman Monteith equation and crop coefficient method recommended by FAO . Besides, the spatial and temporal distribution characteristics of irrigation water requirements in different hydrological years were also analyzed. The results showed that the crop effective precipitation, water requirement and irrigation water requirement for the whole growing period of wheat-maize continuous cropping were 389, 736 and 347 mm, respectively, in the study area. T he ir rig atio n water requirement of wheat-maize continuouscropping in the wet , median, and dry water year was 321, 382 and 423 mm, respectively. The irrigation water requirement of winter wheat was 271-350 mm. The irrigation water requirement of the whole growth period was 26% , 26% and 29% respectively, in the period of turning green to jointing, jointing to heading and heading to maturity . The irrigation water requirement of summer maize was 0-49 mm accounting for 52% and 48% of the total fertility period, respectively. The spatial distribution of crop effective precipitation was decreased slowly from west to east in Shijiazhuang and increased gradually from west to east in Handan. T he water requirement in three counties of Shijiazhuang was slightly higher than those in two counties of Handan. The irrigation water requirement had a zonal distribution in the study area.
2020, 18(4):195-201.
Abstract:
In order to study the relationship between the operation mode of the system and the ice jam, the parameters such as flow rate, Froude number, and water level deviation are taken as indexes. In terms of the selection of conventional operation mode, it is considered that the risk of ice jam caused by the operation of the upstream constant water level is the least, the adjustment and control of the gate during the operation of the down stream constant water level is timely , and the equal volume operation mode is moderate. When the frozen canal pool is frozen, the operation mode of the canal pool is changed from the downstream constant w ater level to the equal volume, resulting in the water level deviation of the canal system. The maximum velocity and the Froude number in the hydraulic response process are smaller than those in the downstream constant water level. The water level deviation in the upstream under simulated conditions decreases by nearly 50% and the maximum velocity decreases by approximately 6 . 5% , respectively . This indicates that switching operation mode is more conducive to maintaining the stability of the canal system during freezing and reducing the risk of an ice jam. Therefore, it is recommended that the frozen canal pool be switched from the downstream constant water level to the equal volume operation during the frozen period.
In order to study the relationship between the operation mode of the system and the ice jam, the parameters such as flow rate, Froude number, and water level deviation are taken as indexes. In terms of the selection of conventional operation mode, it is considered that the risk of ice jam caused by the operation of the upstream constant water level is the least, the adjustment and control of the gate during the operation of the down stream constant water level is timely , and the equal volume operation mode is moderate. When the frozen canal pool is frozen, the operation mode of the canal pool is changed from the downstream constant w ater level to the equal volume, resulting in the water level deviation of the canal system. The maximum velocity and the Froude number in the hydraulic response process are smaller than those in the downstream constant water level. The water level deviation in the upstream under simulated conditions decreases by nearly 50% and the maximum velocity decreases by approximately 6 . 5% , respectively . This indicates that switching operation mode is more conducive to maintaining the stability of the canal system during freezing and reducing the risk of an ice jam. Therefore, it is recommended that the frozen canal pool be switched from the downstream constant water level to the equal volume operation during the frozen period.
2020, 18(4):202-208.
Abstract:
In order to study the mechanical properties and failure laws of lacustrine soft soil under complex stress conditions, constant loading rate ( 0.01 mm/ min) GDS triaxial shear tests were carried out for typical soft soil in Poyang lake area at four matrix suctions ( 0, 50, 100 and 200 kPa) and three net confining pressures ( 100, 200 and 300 kPa) . Triaxial shear stress and stra in curves of lacustrine soft soil, the relationship between matrix suction and deviatoric stress, and the relationship between co nfining pressure and deviatoric stress were obtained. The shear strength of Poyang lake soft soil under different matrix suction and confining pressure was analyzed based on Fredlund’s two-stress variable strength theory of unsaturated soil. The results show that under the same mat rix suction condition, the shear strength increased rapidly with the strain when the unsaturated strength of Poyang lake soft soil was in the low strain range( < 8% ) , but the strength growth slow down in the high strain range. Under the same confining pressure condition, the intensity was positively related with to the suction basic linear r elationship, and the related matrix suction angle was 6.6° which was within the low suction range. Under the condition of four kinds of matrix suction, the scope of its internal friction angle was a range from 21.8° to 26.2°. The total cohesive force range was 16. 7~ 44. 4 kPa. Combined with the strength theory of the double stress variable, the strength theory formula of lacustrine soil in the Poy-ang lake area was proposed.
In order to study the mechanical properties and failure laws of lacustrine soft soil under complex stress conditions, constant loading rate ( 0.01 mm/ min) GDS triaxial shear tests were carried out for typical soft soil in Poyang lake area at four matrix suctions ( 0, 50, 100 and 200 kPa) and three net confining pressures ( 100, 200 and 300 kPa) . Triaxial shear stress and stra in curves of lacustrine soft soil, the relationship between matrix suction and deviatoric stress, and the relationship between co nfining pressure and deviatoric stress were obtained. The shear strength of Poyang lake soft soil under different matrix suction and confining pressure was analyzed based on Fredlund’s two-stress variable strength theory of unsaturated soil. The results show that under the same mat rix suction condition, the shear strength increased rapidly with the strain when the unsaturated strength of Poyang lake soft soil was in the low strain range( < 8% ) , but the strength growth slow down in the high strain range. Under the same confining pressure condition, the intensity was positively related with to the suction basic linear r elationship, and the related matrix suction angle was 6.6° which was within the low suction range. Under the condition of four kinds of matrix suction, the scope of its internal friction angle was a range from 21.8° to 26.2°. The total cohesive force range was 16. 7~ 44. 4 kPa. Combined with the strength theory of the double stress variable, the strength theory formula of lacustrine soil in the Poy-ang lake area was proposed.
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