The oil and gas potential of the Yan'an Formation in the Ordos Basin has yet to be fully tapped. In this study, the pore structure, mobile fluid saturation, and water flooding micro-mechanism of the Yan'an For...The oil and gas potential of the Yan'an Formation in the Ordos Basin has yet to be fully tapped. In this study, the pore structure, mobile fluid saturation, and water flooding micro-mechanism of the Yan'an Formation sandstone are systematically studied through the application of a series of rock physics and fluid experiments. The results show that there is a good positive correlation between porosity and permeability, and the reservoirs are divided into types Ⅰ, Ⅱ, and Ⅲ. Mercury injection tests show that the average pore throat radius of the oil-bearing reservoir ranges from 1 to 7 μm. The displacement pressure of the Yan'an Formation is also relatively low, and it decreases from 0.1 MPa to 0.01 MPa as the rock porosity increases from 11% to 18%. NMR tests show that small (diameter <0.5 μm) and medium pores (diameter ranging from 0.5 to 2.5 μm) are predominant in the reservoir. Different types of reservoirs have different characteristics of relative permeability curve. In addition, when the average oil recovery rate is less than 1 ml/min, the oil displacement efficiency increases faster. However, when the average oil recovery rate is between 1–3.5 ml/min, the oil displacement efficiency is maintained at around 27%–30%. Physical properties of the reservoir, pore-throat structure, experimental pressure difference, and pore volume injected — all have significant effects on oil displacement efficiency. For Type Ⅰ and Type Ⅱ reservoirs, the increase of the pore volume injected has a significant effect on oil displacement efficiency. However, for Type Ⅲ reservoirs, the change of pore volume injected has insignificant effect on oil displacement efficiency. This study provides a reference for the formulation of estimated ultimate recovery (EUR) measures for similar sandstone reservoirs.展开更多
Starting from the fact that water is quite arguably the source of life, the authors agreed to set up a project on water and name it: "REFLECTION". Particular focus was placed on the following issues: water in natu...Starting from the fact that water is quite arguably the source of life, the authors agreed to set up a project on water and name it: "REFLECTION". Particular focus was placed on the following issues: water in nature, importance of water in human life, physical and chemical properties of water, protection of water in nature. The aim of the project was to make students aware of the importance of water for health as well as to help them develop a rational relationship towards drinking water. In order to find answers to the issues raised, the authors designed worksheets, PowerPoint presentations, educational games (ecological postcards, dominoes, memory games, etc.). The authors even tried our hand at making a comic strip. Students learned about the influence of water on health, as well as about water content in particular foods. The long-term goal of the project is to introduce children to scientific approach and methodology. Through active participation and dialogue, students discover cooperative learning and acquire skills that will be beneficial to them as well as to the wider community. Working on the project, students' evidence that the role of an individual is a key one in building a better world. This insight helps develop their civic skills and attitudes that serve as the starting point for environmental education. The authors made numerous adaptations and implemented individual approach with the goal of training students for independent work and life according to their personal abilities in line with the principles of inclusive education. Students conduct experiments following step-by-step instructions on specially adapted worksheets. Each student gets positive feedback and experiences the joy of success that leads to the development of self-confidence and love of work and learning.展开更多
Twenty two fresh water fish samples namely Puntius sarana (Shawrputi), Cyprinus carpio (Karp), Oreochromis niloticos (Telapia), Channa punctatus (Taki), Wallogonia attu (Boal), Eutropiichthys vacha (Bacha)...Twenty two fresh water fish samples namely Puntius sarana (Shawrputi), Cyprinus carpio (Karp), Oreochromis niloticos (Telapia), Channa punctatus (Taki), Wallogonia attu (Boal), Eutropiichthys vacha (Bacha), Macrognathus aculiatus (Baim), Ailia coila (Kajoli), Mystus cavasisus(Gulsa), Ompok pabda (Pabdha), Corica soborna (Kachki), Mystus vittatus (Tengra), Glossogobius giuris (Baila), Macrobrachium malcolmsli (Chingri), Amblypharyngodon microlepis (Mola), Anabas testudineus (Koi), Macrognathus aculiatus (Baim), Channa striatus (Shole), Heteropnueste fossilis (Shing), Puntius sophore (Small Puti) and Pseudambassis ranga (Telapia) were collected from two rivers and one cultured fish pond. The samples were extracted by QuEChERS method, cleaned up with conc. H2SO4 treatment and cleaned extracts were analyzed by GC-ECD. Small size cultured rui fish sample which did show detectable amount of DDT and its metabohtes was used for the recovery experiments. Percent recovery was found to be in the range of 70%-113%. Amount of total DDTs were found to be 54.34, 48.81, 62.09, 54.72,78.81, 60.07, 47.0, 42.7, 26.31, 10.36, 25.32, 12.96, 20.10, 12.78, 17.65, and 4.71, 8.58, 11.3 and 19.01 ng/g in gulsa, pabhda, baila, bacha, baim, small purl, tengra, chanda, kachki, boal, taki, chingri, mola, shole, shing, koi, swarpurl, karp and telapia fish samples, respectively. However, the residual amounts of DDTs in all the fish samples were below maximum residue limit (MRL of DDTs in fish 5.0 mg/kg) according to Codex Alimentarius Commission. The ratios of 4,4'-DDT/DDTs were in the range of 0.03-0.44 which indicated that exposure to DDT is not due to recent use.展开更多
The Keriya River Basin is located in an extremely arid climate zone on the southern edge of the Tarim Basin of Northwest China,exhibiting typical mountain-oasis-desert distribution characteristics.In recent decades,cl...The Keriya River Basin is located in an extremely arid climate zone on the southern edge of the Tarim Basin of Northwest China,exhibiting typical mountain-oasis-desert distribution characteristics.In recent decades,climate change and human activities have exerted significant impacts on the service functions of watershed ecosystems.However,the trade-offs and synergies between ecosystem services(ESs)have not been thoroughly examined.This study aims to reveal the spatiotemporal changes in ESs within the Keriya River Basin from 1995 to 2020 as well as the trade-offs and synergies between ESs.Leveraging the Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)and Revised Wind Erosion Equation(RWEQ)using land use/land cover(LULC),climate,vegetation,soil,and hydrological data,we quantified the spatiotemporal changes in the five principal ESs(carbon storage,water yield,food production,wind and sand prevention,and habitat quality)of the watershed from 1995 to 2020.Spearman correlation coefficients were used to analyze the trade-offs and synergies between ES pairs.The findings reveal that water yield,carbon storage,and habitat quality exhibited relatively high levels in the upstream,while food production and wind and sand prevention dominated the midstream and downstream,respectively.Furthermore,carbon storage,food production,wind and sand prevention,and habitat quality demonstrated an increase at the watershed scale while water yield exhibited a decline from 1995 to 2020.Specifically,carbon storage,wind and sand prevention,and habitat quality presented an upward trend in the upstream but downward trend in the midstream and downstream.Food production in the midstream showed a continuously increasing trend during the study period.Trade-off relationships were identified between water yield and wind and sand prevention,water yield and carbon storage,food production and water yield,and habitat quality and wind and sand prevention.Prominent temporal and spatial synergistic relationships were observed between different ESs,notably between carbon storage and habitat quality,carbon storage and food production,food production and wind and sand prevention,and food production and habitat quality.Water resources emerged as a decisive factor for the sustainable development of the basin,thus highlighting the intricate trade-offs and synergies between water yield and the other four services,particularly the relationship with food production,which warrants further attention.This research is of great significance for the protection and sustainable development of river basins in arid areas.展开更多
Arsenic has long been recognized as a poison.Arsenic in water supplies that are used for both drinking and crop irrigation can expose many people chronically to elevated levels of arsenic.
The overarching goal of this study was to perform a comprehensive metaanalysis of irrigated agricultural Crop Water Productivity(CWP)of the world’s three leading crops:wheat,corn,and rice based on three decades of r...The overarching goal of this study was to perform a comprehensive metaanalysis of irrigated agricultural Crop Water Productivity(CWP)of the world’s three leading crops:wheat,corn,and rice based on three decades of remote sensing and non-remote sensing-based studies.Overall,CWP data from 148 crop growing study sites(60 wheat,43 corn,and 45 rice)spread across the world were gathered from published articles spanning 31 different countries.There was overwhelming evidence of a significant increase in CWP with an increase in latitude for predominately northern hemisphere datasets.For example,corn grown in latitude 40–50°had much higher mean CWP(2.45 kg/m^(3))compared to mean CWP of corn grown in other latitudes such as 30–40°(1.67 kg/m^(3))or 20–30°(0.94 kg/m^(3)).The same trend existed for wheat and rice as well.For soils,none of the CWP values,for any of the three crops,were statistically different.However,mean CWP in higher latitudes for the same soil was significantly higher than the mean CWP for the same soil in lower latitudes.This applied for all three crops studied.For wheat,the global CWP categories were low(≤0.75 kg/m^(3)),medium(>0.75 to<1.10 kg/m^(3)),and high CWP(≥1.10 kg/m^(3)).For corn the global CWP categories were low(≤1.25 kg/m^(3)),medium(>1.25 to≤1.75 kg/m^(3)),and high(>1.75 kg/m^(3)).For rice the global CWP categories were low(≤0.70 kg/m^(3)),medium(>0.70 to≤1.25 kg/m^(3)),and high(>1.25 kg/m^(3)).USA and China are the only two countries that have consistently high CWP for wheat,corn,and rice.Australia and India have medium CWP for wheat and rice.India’s corn,however,has low CWP.Egypt,Turkey,Netherlands,Mexico,and Israel have high CWP for wheat.Romania,Argentina,and Hungary have high CWP for corn,and Philippines has high CWP for rice.All other countries have either low or medium CWP for all three crops.Based on data in this study,the highest consumers of water for crop production also have the most potential for water savings.These countries are USA,India,and China for wheat;USA,China,and Brazil for corn;India,China,and Pakistan for rice.For example,even just a 10%increase in CWP of wheat grown in India can save 6974 billion liters of water.This is equivalent to creating 6974 lakes each of 100 m^(3)in volume that leads to many benefits such as acting as‘water banks’for lean season,recreation,and numerous ecological services.This study establishes the volume of water that can be saved for each crop in each country when there is an increase in CWP by 10%,20%,and 30%.展开更多
There is a growing recognition of the interdependencies among the supply systems that rely upon food,water and energy.Billions of people lack safe and sufficient access to these systems,coupled with a rapidly growing ...There is a growing recognition of the interdependencies among the supply systems that rely upon food,water and energy.Billions of people lack safe and sufficient access to these systems,coupled with a rapidly growing global demand and increasing resource constraints.Modeling frameworks are considered one of the few means available to understand the complex interrelationships among the sectors,however development of nexus related frameworks has been limited.We describe three opensource models well known in their respective domains(i.e.TerrSysMP,WOFOST and SWAT)where components of each if combined could help decision-makers address the nexus issue.We propose as a first step the development of simple workflows utilizing essential variables and addressing components of the above-mentioned models which can act as building-blocks to be used ultimately in a comprehensive nexus model framework.The outputs of the workflows and the model framework are designed to address the SDGs.展开更多
Central Asia is one of the most vulnerable regions on the planet earth to global climate change, depending on very fragile natural resources. The Soviet legacy has left the five countries (Kazakhstan, Tajikistan, Kyr...Central Asia is one of the most vulnerable regions on the planet earth to global climate change, depending on very fragile natural resources. The Soviet legacy has left the five countries (Kazakhstan, Tajikistan, Kyrgyzstan, Turkmenistan, and Uzbekistan) with a highly integrated system but they are facing great challenges with tensions that hinder regional coordination of food and water resources. With increasing climate variability and warming trend in the region, food and water security issues become even more crucial now and, if not addressed properly, could affect the regional stability. The long-term drivers of these two most critical elements, food and water, are climate change; the immediate and probably more drastic factors affecting the food and water security are land uses driven by institutional change and economic incentives. As a feedback, changes in land use and land cover have directly implications on water uses, food production, and lifestyles of the rural community in the region. Regional and international efforts have been made to holistically understand the cause, extent, rate and societal implications of land use changes in the region. Much of these have been understood, or under investiga- tion by various projects, but solutions or research effort to develop solutions, to these urgent regional issues are lacking. This article, serves as an introduction to the special issue, provides a brief overview of the challenges facing the Central Asian countries and various interna- tional efforts in place that resulted in the publications of this special issue.展开更多
基金supported by the Guiding Science and Technology Planning Project of Daqing(Grant No.zd-2021-36)Postdoctoral Scientific Research Developmental Fund of Heilongjiang Province,China(Grant No.LBH-Z21084)Natural Science Foundation of Heilongjiang Province(Grant No.LH 2022E019).
文摘The oil and gas potential of the Yan'an Formation in the Ordos Basin has yet to be fully tapped. In this study, the pore structure, mobile fluid saturation, and water flooding micro-mechanism of the Yan'an Formation sandstone are systematically studied through the application of a series of rock physics and fluid experiments. The results show that there is a good positive correlation between porosity and permeability, and the reservoirs are divided into types Ⅰ, Ⅱ, and Ⅲ. Mercury injection tests show that the average pore throat radius of the oil-bearing reservoir ranges from 1 to 7 μm. The displacement pressure of the Yan'an Formation is also relatively low, and it decreases from 0.1 MPa to 0.01 MPa as the rock porosity increases from 11% to 18%. NMR tests show that small (diameter <0.5 μm) and medium pores (diameter ranging from 0.5 to 2.5 μm) are predominant in the reservoir. Different types of reservoirs have different characteristics of relative permeability curve. In addition, when the average oil recovery rate is less than 1 ml/min, the oil displacement efficiency increases faster. However, when the average oil recovery rate is between 1–3.5 ml/min, the oil displacement efficiency is maintained at around 27%–30%. Physical properties of the reservoir, pore-throat structure, experimental pressure difference, and pore volume injected — all have significant effects on oil displacement efficiency. For Type Ⅰ and Type Ⅱ reservoirs, the increase of the pore volume injected has a significant effect on oil displacement efficiency. However, for Type Ⅲ reservoirs, the change of pore volume injected has insignificant effect on oil displacement efficiency. This study provides a reference for the formulation of estimated ultimate recovery (EUR) measures for similar sandstone reservoirs.
文摘Starting from the fact that water is quite arguably the source of life, the authors agreed to set up a project on water and name it: "REFLECTION". Particular focus was placed on the following issues: water in nature, importance of water in human life, physical and chemical properties of water, protection of water in nature. The aim of the project was to make students aware of the importance of water for health as well as to help them develop a rational relationship towards drinking water. In order to find answers to the issues raised, the authors designed worksheets, PowerPoint presentations, educational games (ecological postcards, dominoes, memory games, etc.). The authors even tried our hand at making a comic strip. Students learned about the influence of water on health, as well as about water content in particular foods. The long-term goal of the project is to introduce children to scientific approach and methodology. Through active participation and dialogue, students discover cooperative learning and acquire skills that will be beneficial to them as well as to the wider community. Working on the project, students' evidence that the role of an individual is a key one in building a better world. This insight helps develop their civic skills and attitudes that serve as the starting point for environmental education. The authors made numerous adaptations and implemented individual approach with the goal of training students for independent work and life according to their personal abilities in line with the principles of inclusive education. Students conduct experiments following step-by-step instructions on specially adapted worksheets. Each student gets positive feedback and experiences the joy of success that leads to the development of self-confidence and love of work and learning.
文摘Twenty two fresh water fish samples namely Puntius sarana (Shawrputi), Cyprinus carpio (Karp), Oreochromis niloticos (Telapia), Channa punctatus (Taki), Wallogonia attu (Boal), Eutropiichthys vacha (Bacha), Macrognathus aculiatus (Baim), Ailia coila (Kajoli), Mystus cavasisus(Gulsa), Ompok pabda (Pabdha), Corica soborna (Kachki), Mystus vittatus (Tengra), Glossogobius giuris (Baila), Macrobrachium malcolmsli (Chingri), Amblypharyngodon microlepis (Mola), Anabas testudineus (Koi), Macrognathus aculiatus (Baim), Channa striatus (Shole), Heteropnueste fossilis (Shing), Puntius sophore (Small Puti) and Pseudambassis ranga (Telapia) were collected from two rivers and one cultured fish pond. The samples were extracted by QuEChERS method, cleaned up with conc. H2SO4 treatment and cleaned extracts were analyzed by GC-ECD. Small size cultured rui fish sample which did show detectable amount of DDT and its metabohtes was used for the recovery experiments. Percent recovery was found to be in the range of 70%-113%. Amount of total DDTs were found to be 54.34, 48.81, 62.09, 54.72,78.81, 60.07, 47.0, 42.7, 26.31, 10.36, 25.32, 12.96, 20.10, 12.78, 17.65, and 4.71, 8.58, 11.3 and 19.01 ng/g in gulsa, pabhda, baila, bacha, baim, small purl, tengra, chanda, kachki, boal, taki, chingri, mola, shole, shing, koi, swarpurl, karp and telapia fish samples, respectively. However, the residual amounts of DDTs in all the fish samples were below maximum residue limit (MRL of DDTs in fish 5.0 mg/kg) according to Codex Alimentarius Commission. The ratios of 4,4'-DDT/DDTs were in the range of 0.03-0.44 which indicated that exposure to DDT is not due to recent use.
基金financially supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region(2022D01C77)the PhD Programs Foundation of Xinjiang University(BS202105).
文摘The Keriya River Basin is located in an extremely arid climate zone on the southern edge of the Tarim Basin of Northwest China,exhibiting typical mountain-oasis-desert distribution characteristics.In recent decades,climate change and human activities have exerted significant impacts on the service functions of watershed ecosystems.However,the trade-offs and synergies between ecosystem services(ESs)have not been thoroughly examined.This study aims to reveal the spatiotemporal changes in ESs within the Keriya River Basin from 1995 to 2020 as well as the trade-offs and synergies between ESs.Leveraging the Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)and Revised Wind Erosion Equation(RWEQ)using land use/land cover(LULC),climate,vegetation,soil,and hydrological data,we quantified the spatiotemporal changes in the five principal ESs(carbon storage,water yield,food production,wind and sand prevention,and habitat quality)of the watershed from 1995 to 2020.Spearman correlation coefficients were used to analyze the trade-offs and synergies between ES pairs.The findings reveal that water yield,carbon storage,and habitat quality exhibited relatively high levels in the upstream,while food production and wind and sand prevention dominated the midstream and downstream,respectively.Furthermore,carbon storage,food production,wind and sand prevention,and habitat quality demonstrated an increase at the watershed scale while water yield exhibited a decline from 1995 to 2020.Specifically,carbon storage,wind and sand prevention,and habitat quality presented an upward trend in the upstream but downward trend in the midstream and downstream.Food production in the midstream showed a continuously increasing trend during the study period.Trade-off relationships were identified between water yield and wind and sand prevention,water yield and carbon storage,food production and water yield,and habitat quality and wind and sand prevention.Prominent temporal and spatial synergistic relationships were observed between different ESs,notably between carbon storage and habitat quality,carbon storage and food production,food production and wind and sand prevention,and food production and habitat quality.Water resources emerged as a decisive factor for the sustainable development of the basin,thus highlighting the intricate trade-offs and synergies between water yield and the other four services,particularly the relationship with food production,which warrants further attention.This research is of great significance for the protection and sustainable development of river basins in arid areas.
文摘Arsenic has long been recognized as a poison.Arsenic in water supplies that are used for both drinking and crop irrigation can expose many people chronically to elevated levels of arsenic.
基金U.S.Geological Survey WaterSMART(Sustain and Manage America’s Resources for Tomorrow)project.
文摘The overarching goal of this study was to perform a comprehensive metaanalysis of irrigated agricultural Crop Water Productivity(CWP)of the world’s three leading crops:wheat,corn,and rice based on three decades of remote sensing and non-remote sensing-based studies.Overall,CWP data from 148 crop growing study sites(60 wheat,43 corn,and 45 rice)spread across the world were gathered from published articles spanning 31 different countries.There was overwhelming evidence of a significant increase in CWP with an increase in latitude for predominately northern hemisphere datasets.For example,corn grown in latitude 40–50°had much higher mean CWP(2.45 kg/m^(3))compared to mean CWP of corn grown in other latitudes such as 30–40°(1.67 kg/m^(3))or 20–30°(0.94 kg/m^(3)).The same trend existed for wheat and rice as well.For soils,none of the CWP values,for any of the three crops,were statistically different.However,mean CWP in higher latitudes for the same soil was significantly higher than the mean CWP for the same soil in lower latitudes.This applied for all three crops studied.For wheat,the global CWP categories were low(≤0.75 kg/m^(3)),medium(>0.75 to<1.10 kg/m^(3)),and high CWP(≥1.10 kg/m^(3)).For corn the global CWP categories were low(≤1.25 kg/m^(3)),medium(>1.25 to≤1.75 kg/m^(3)),and high(>1.75 kg/m^(3)).For rice the global CWP categories were low(≤0.70 kg/m^(3)),medium(>0.70 to≤1.25 kg/m^(3)),and high(>1.25 kg/m^(3)).USA and China are the only two countries that have consistently high CWP for wheat,corn,and rice.Australia and India have medium CWP for wheat and rice.India’s corn,however,has low CWP.Egypt,Turkey,Netherlands,Mexico,and Israel have high CWP for wheat.Romania,Argentina,and Hungary have high CWP for corn,and Philippines has high CWP for rice.All other countries have either low or medium CWP for all three crops.Based on data in this study,the highest consumers of water for crop production also have the most potential for water savings.These countries are USA,India,and China for wheat;USA,China,and Brazil for corn;India,China,and Pakistan for rice.For example,even just a 10%increase in CWP of wheat grown in India can save 6974 billion liters of water.This is equivalent to creating 6974 lakes each of 100 m^(3)in volume that leads to many benefits such as acting as‘water banks’for lean season,recreation,and numerous ecological services.This study establishes the volume of water that can be saved for each crop in each country when there is an increase in CWP by 10%,20%,and 30%.
基金The authors would like to acknowledge the European Commission Horizon 2020 Program that funded both the ERAPLANET/GEOEssential(Grant Agreement no.689443)ConnectinGEO(Grant Agreement no.641538)projects.
文摘There is a growing recognition of the interdependencies among the supply systems that rely upon food,water and energy.Billions of people lack safe and sufficient access to these systems,coupled with a rapidly growing global demand and increasing resource constraints.Modeling frameworks are considered one of the few means available to understand the complex interrelationships among the sectors,however development of nexus related frameworks has been limited.We describe three opensource models well known in their respective domains(i.e.TerrSysMP,WOFOST and SWAT)where components of each if combined could help decision-makers address the nexus issue.We propose as a first step the development of simple workflows utilizing essential variables and addressing components of the above-mentioned models which can act as building-blocks to be used ultimately in a comprehensive nexus model framework.The outputs of the workflows and the model framework are designed to address the SDGs.
文摘Central Asia is one of the most vulnerable regions on the planet earth to global climate change, depending on very fragile natural resources. The Soviet legacy has left the five countries (Kazakhstan, Tajikistan, Kyrgyzstan, Turkmenistan, and Uzbekistan) with a highly integrated system but they are facing great challenges with tensions that hinder regional coordination of food and water resources. With increasing climate variability and warming trend in the region, food and water security issues become even more crucial now and, if not addressed properly, could affect the regional stability. The long-term drivers of these two most critical elements, food and water, are climate change; the immediate and probably more drastic factors affecting the food and water security are land uses driven by institutional change and economic incentives. As a feedback, changes in land use and land cover have directly implications on water uses, food production, and lifestyles of the rural community in the region. Regional and international efforts have been made to holistically understand the cause, extent, rate and societal implications of land use changes in the region. Much of these have been understood, or under investiga- tion by various projects, but solutions or research effort to develop solutions, to these urgent regional issues are lacking. This article, serves as an introduction to the special issue, provides a brief overview of the challenges facing the Central Asian countries and various interna- tional efforts in place that resulted in the publications of this special issue.