Distributions and risk assessment of heavy metals in solid waste in lead-zinc mining areas and across the soil, water body, sediment and agricultural product ecosystem in their surrounding areas

To identify the root causes of heavy metal contamination in soils as well as prevent and control such contamination from its sources,this study explored the accumulation patterns and ecological risks of heavy metals like Cd and Pb in solid waste in mining areas and across the water body,sediment,soil and agricultural product ecosystem surrounding the mining areas.Focusing on the residual solid waste samples in lead-zinc deposits in a certain area of Guizhou Province,along with samples of topsoils,irrigation water,river sediments,and crops from surrounding areas.This study analyzed the distributions of eight heavy metals,i.e.,Cd,As,Cr,Hg,Pb,Zn,Cu,and Ni,in the samples through field surveys and sample tests.Furthermore,this study assessed the contamination levels and ecological risks of heavy metals in soils,sediments,and agricultural products using methods such as the single-factor index,Nemerow composite index,and potential ecological risk assessment.The results indicate that heavy metals in the solid waste samples all exhibited concentrations exceeding their risk screening values,with 60%greater than their risk intervention values.The soils and sediments demonstrate slight and moderate comprehensive ecological risks of heavy metals.The single-factor potential ecological risks of heavy metals in both the soil and sediment samples decreased in the order of Hg,Cd,Pb,As,Cu,Zn,Cr,and Ni,suggesting the same sources of heavy metals in the soils and sediments.Most of the agricultural product samples exhibited over-limit concentrations of heavy metals dominated by Cd,Pb,Ni,and Cr,excluding Hg and As.The agricultural product assessment using the Nemerow composite index reveals that 35%of the agricultural product samples reached the heavy metal contamination level,implying that the agricultural products from farmland around the solid waste dumps have been contaminated with heavy metals.The eight heavy metals in the soil,sediment,and agricultural product samples manifested high coefficients of variation(CVs),indicating pronounced spatial variability.This suggests that their concentrations in soils,sediments,and agricultural products are significantly influenced by human mining activities.Additionally,the agricultural products exhibit strong transport and accumulation capacities for Cd,Cu,and Zn.

Climate Characteristics in Three Gorges Reservoir Area after Water Storage and Its Impact on the Production Potential

Based on the meteorological data from 33 stations of Three Gorges Reservoir from 1960 to 2008,climate yield of rice,corn and winter wheat and the changes of climatic potential productivity after water storage in Three Gorges Reservoir were calculated by the dynamic statistic model of crop growth.The results showed that the temperature in Three Gorges Reservoir was fluctuant decreased before late 1980s,and warmed rapidly after the late 1980s.The precipitation had little change before the late 1990s and had a slight decrease after the late 1990s.Sunshine hours were more in 1960s and 1970s,and then it changed little after 1980s.After water storage,the temperature increased in Three Gorges Reservoir as a whole.The precipitation decreased in the south of Three Gorges Reservoir,while it increased in the northwest of Three Gorges Reservoir.The sunshine hours were reduced except that in the vicinity of Dianjiang.After water storage,climatic potential productivity of rice decreased in the northwest and the northeast,while it increased in the south of Three Gorges Reservoir.The climatic potential productivity of corn decreased in the northeast and the southwest,but increased in the rest of Three Gorges Reservoir.The climatic potential productivity of winter wheat increased almost in total.

A Comparative Study of Different Methods on Quality Assessment of Soil Environment Polluted by Zinc in Agricultural Production Areas——A Case Study in Shulan City of Jilin Province

[Objective] The aim was to explore evaluated precision on quality of soil environment polluted with zinc in agricultural production areas and to provide references for verification of production area.[Method] In Shulan City in Jilin Province,soils were sampled and analyzed in a laboratory using single-factor pollution index and GIS based spatial interpolation.The quality of environment polluted with zinc was assessed and related methods were compared according to Environment Quality Standard of Green Food Production Area.[Result] Spatial interpolation of zinc in soils based on GIS proved more precise than traditional methods;cokriging method with co-factors was higher in precision than common cokriging;cokriging method with zinc and organic matter was higher in precision than cokriging with zinc alone.[Conclusion] Quality assessment on environment polluted with zinc based on GIS interpolation is more scientific and reasonable than traditional methods.

Promoting grain production through high-standard farmland construction:Evidence in China

Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capacity.Based on panel data from 31 sample provinces,autonomous regions,and municipalities in China from 2005–2017,this study explored the impact of HSFC on grain yield using the difference-in-differences(DID)method.The results showed that HSFC significantly increased total grain production,which is robust to various checks.HSFC increased grain yield through three potential mechanisms.First,it could increase the grain replanting index.Second,it could effectively reduce yield loss due to droughts and floods.Last,HSFC could strengthen the cultivated land by renovating the low-and medium-yielding fields.Heterogeneity analysis found that the HSFC farmland showed a significant increase in grain yield only in the main grain-producing areas and balanced areas.In addition,HSFC significantly increased the yields of rice,wheat,and maize while leading to a reduction in soybean yields.The findings suggest the government should continue to promote HSFC,improve construction standards,and strictly control the“non-agriculturalization”and“non-coordination”of farmland to increase grain production further.At the same time,market mechanisms should be used to incentivize soybean farming,improve returns and stabilize soybean yields.

Production Characteristics and the Control Factors of Surface Wells for Relieved Methane Drainage in the Huainan Mining Area

Based on the production data of a large number of surface drainage wells in the Huainan mining area,the present study shows that four types of typical production characteristics for relieved methane wells are recognized,of which the stable type for production and gas concentration is the most dominate,as determined by a comprehensive study on the volume and concentration of drained gases, as well as the stress changes of rocks influenced by mining.Some influence factors for the productive differences of the drainage wells were also been discussed.The results indicate that protective coal-seam mining has a significant effect on overlying strata,which promotes the development of pores and fractures of coal reservoirs for methane desorption and migration;however,the production and the stability of drainage wells are affected by deformation and damage of the overlying strata.The second distribution of strata stress is caused by mining engineering,and if the stress load is larger than the carrying capacity of the extraction well,the gas production would be influenced by the drainage well that has been damaged by rock movement.Furthermore,the case damage occurs first in the weak, lithologic interface by its special mechanical properties.The stability of drainage wells and the production status are also influenced by the different drilling techniques,uneven distribution of gas concentration,and combination of gob gas and methane from the protected layer.

Distribution of gas hydrate reservoir in the first production test region of the Shenhu area,South China Sea

In May and July of 2017,China Geological Survey (CGS),and Guangzhou Marine Geological Survey (GMGS)carried out a production test of gas hydrate in the Shenhu area of the South China Sea and acquired a breakthrough of two months continuous gas production and nearly 3.1×10^5 m^3 of production. The gas hydrate reservoir in the Shenhu area of China,is mainly composed of fine-grained clay silt with low permeability,and very difficult for exploitation,which is very different from those discovered in the USA,and Canada (both are conglomerate),Japan (generally, coarse sand)and India (fracture-filled gas hydrate).Based on 3D seismic data preserved-amplitude processing and fine imaging,combined with logging-while-drilling (LWD)and core analysis data,this paper discusses the identification and reservoir characterization of gas hydrate orebodies in the Shenhu production test area.We also describe the distribution characteristics of the gas hydrate deposits and provided reliable data support for the optimization of the production well location.Through BSR feature recognition,seismic attribute analysis, model based seismic inversion and gas hydrate reservoir characterization,this paper describes two relatively independent gas hydrate orebodies in the Shenhu area,which are distributed in the north-south strip and tend to be thicker in the middle and thinner at the edge.The effective thickness of one orebody is bigger but the distribution area is relatively small.The model calculation results show that the distribution area of the gas hydrate orebody controlled by W 18/W 19 is about 11.24 km^2,with an average thickness of 19 m and a maximum thickness of 39 m,and the distribution area of the gas hydrate orebody controlled by W11/W17 is about 6.42 km^2,with an average thickness of 26 m and a maximum thickness of 90 m.

Agricultural Production Structure Optimization: A Case Study of Major Grain Producing Areas, China

A large number of mathematical models were developed for supporting agricultural production structure optimization decisions; however, few of them can address various uncertainties existing in many factors （e.g., eco-social benefit maximization, food security, employment stability and ecosystem balance）. In this study, an interval-probabilistic agricultural production structure optimization model （IPAPSOM） is formulated for tackling uncertainty presented as discrete intervals and/or probability distribution. The developed model improves upon the existing probabilistic programming and inexact optimization approaches. The IPAPSOM considers not only food security policy constraints, but also involves rural households’income increase and eco-environmental conversation, which can effectively reflect various interrelations among different aspects in an agricultural production structure optimization system. Moreover, it can also help examine the reliability of satisfying （or risk of violating） system constraints under uncertainty. The model is applied to a real case of long-term agricultural production structure optimization in Dancheng County, which is located in Henan Province of Central China as one of the major grain producing areas. Interval solutions associated with different risk levels of constraint violation are obtained. The results are useful for generating a range of decision alternatives under various system benefit conditions, and thus helping decision makers to identify the desired agricultural production structure optimization strategy under uncertainty.

Variation Characteristics of Hydrothermal Resources Effectiveness Under the Background of Climate Change in Southern Rice Production Area of China

The spatiotemporal characteristics of hydrothermal resources in southern rice production area of China have changed under the background of climate change,and this change would affect the effectiveness of hydrothermal resources during local rice growing period.According to the cropping system subdivision in southern rice production area of China during 1980s,this study used climate data from 254 meteorological stations and phonological data from 168 agricultural observation stations in the south of China,and adopted 6 international evaluation indices about the effectiveness of hydrothermal resources to analyze the temporal and spatial characteristics of hydrothermal resources during the growing period of single cropping rice system and double cropping rice system for 16 planting zones in the whole study area.The results showed that：in southern rice production area of China,the effectiveness of thermal resources of single cropping rice area（SCRA） was less than that of double cropping rice area（DCRA）,whereas the effectiveness of thermal resources of both SARA and DCRA showed a decreasing trend.The index value of effective precipitation satisfaction of SCRA was higher than that of DCRA,nevertheless the index value of effective precipitation satisfaction of both SCRA and DCRA showed a decreasing trend.There was a significant linear relationship between effective thermal resource and water demand,likely water demand increased by 18 mm with every 100°C d increase of effective heat.Effective precipitation satisfaction index（EPSI） showed a negative correlation with effective heat,yet showed a positive correlation with effective precipitation.EPSI reduced by 1% when effective heat resource increased by 125°C d.This study could provide insights for policy makers,land managers or farmers to improve water and heat resource uses and rationally arrange rice production activities under global climate change condition.

Secondary Production of Macrobenthos in Mangrove Area of Tong'an Bay,China

Studies on secondary production lead to a better understanding of the functions of the macrobenthic ecosystem.Basedon the macrobenthic data obtained at 6 sampling stations from April 2006 to January 2007,Brey's(1990)empirical formula wasapplied to calculate the secondary production of macrobenthos in the mangrove area of Tong'an Bay.The results showed that themean annual secondary production of macrobenthos was 13.24 gAFDWm-2-a-1.The mean secondary production in the mangrovehabitat was 12.22 gAFDWm-2-a-1,lower than that in the non-mangrove habitat,which was 15.29 gAFDWm-2-a-1.Two possible rea-sons existed for this difference.First,mollusk and crustacean,which contribute more to the secondary production,probably benefitfrom longer inundation period in the non-mangrove habitat.Second,the higher organic matter in the mangrove habitat results in hy-poxia in the bottom sediment,which may decrease the secondary production.The annual mean production-to-biomass(P/B)ratio inTong'an Bay was 1.17,with a ratio of 1.27 in the mangrove habitat and 0.96 in the non-mangrove habitat,which was coincident withthe much higher density of Limnodriloides sp.and Corophium sp.in the mangrove habitat than in the non-mangrove habitat.Themaximum secondary production and P/B ratio of macrobenthos both appeared at sampling station FL2 in April,2006(namelyApril-FL2)with values of 31.38 gAFDWm-2-a-1and 2.20,respectively.The macrobenthic secondary production in Tong'an Bay islower than those in other intertidal studies except that in Haitan Strait,the reason being the different sediment properties.The P/Bratio in Tong'an Bay was the lowest due to the high proportion of crustaceans in the macrobenthic community.

Distributed optical fiber acoustic sensor for in situ monitoring of marine natural gas hydrates production for the first time in the Shenhu Area,China

The distributed acoustic sensor(DAS)uses a single optical cable as the sensing unit,which can capture the acoustic and vibration signals along the optical cable in real-time.So it is suitable for monitoring downhole production activities in the process of oil and gas development.The authors applied the DAS system in a gas production well in the South China Sea for in situ monitoring of the whole wellbore for the first time and obtained the distributed acoustic signals along the whole wellbore.These signals can clearly distinguish the vertical section,curve section,and horizontal production section.The collected acoustic signal with the frequency of approximately 50 Hz caused by the electric submersible pump exhibit a signal-to-noise ratio higher than 27 dB.By analyzing the acoustic signals in the production section,it can be located the layers with high gas production rates.Once an accurate physical model is built in the future,the gas production profile will be obtained.In addition,the DAS system can track the trajectory of downhole tools in the wellbore to guide the operation.Through the velocity analysis of the typical signals,the type of fluids in the wellbore can be distinguished.The successful application of the system provides a promising whole wellbore acoustic monitoring tool for the production of marine gas hydrate,with a good application prospect.

Increasing Subsidies to Main Grain Production Area——Necessity of the Rejuvenation of Northeast China

As an old industrial base, Northeast China is one of the most important grain production base. To rejuvenate Northeast China, it is necessary to strengthen farming products processing, lengthen industrial chain and develop sustainable agriculture.

A Study on Japanese Traditional Rice Production Technique in Warm Areas and Its Modern Ecological Value

Japanese traditional rice production technique features " sparse seeding,long cultivation,scattered planting and limited transplanting",and scientific rice production methods of deep plowing,fertilization,weeding,irrigation and drainage are employed.This technique has reversed the common practice of " dense seeding and planting" in rice paddies and changed the history of growing rice spikes purely out of stems,thus enabling stable and high yields of several tillering grain crops including rice.The technique can provide a useful reference for developing modern rice production in warm areas.

Assessing the Vulnerability of Agricultural Production Activities in the Coastal Area of Thua Thien Hue Province, Vietnam by GIS Analysis Tools

Using Geography Information System (GIS) tools and remote sensing data in assessing the level of vulnerability of agricultural production activities in the coastal area has become more efficient in the recent years. This research has identified the sensitivity index (S) (including the traffic access index;the impact of residential areas;the impacts of industrial zones;the community dependence level), exposure index (E) (the sea level rises to 2100;the temperature change to 2100), the adaptable capacity index (AC) (slope;morphology), thereby synthesizing the vulnerability index (V). Based on the indexes to calculate vulnerability, the high to very high vulnerability area is 37,081.44 ha, accounting for 68.09%;the average vulnerability level is 15,286.49 ha, accounting for 28.07%;the low to very low vulnerability level with an area is 2087.82 ha, accounting for 3.84% of the total area. With a high and very high vulnerability accounting for 68.09%, there will be great influences on the lives of resident in the area, especially agricultural production.

Simulating deforestation of Nepal by area production model

Based on the growth rates of population, Gross Domestic Products (GDP) and agriculture productivity, the areas of deforestation were predicted in Jutp ani village, Chitwan district, Nepal by Area Production Model (APM). Through the APM simulation in this study, all of forestland will be transferred into agricu ltural land in 2030 at the rate of 24% per year on the current productivity. And if the productivity of subsistence food crop is assumed to increase at the rate of 1%, the productivity of market crop and export crop increase at the rate of 2% annually, deforestation rate will decrease to 17% per year, but only 124 hm2 forest land will be left till 2038. The agriculture productivity is a very impor tant factor for the deforestation, so intensification of agriculture management is more important.

Distribution of Radioactive Elements and Their Relation to the Radiogenic Heat Production at Jabal Kharazah Area, North Eastern Desert, Egypt

A map of radiogenic heat production RHP was constructed from airborne spectral gamma-ray data of Jabal Kharazah area, North Eastern Desert, Egypt. The study area possesses a range of RHP varying from 0.2 to 5.7 μW/m-3 with an average value 1.38 μW/m-3, while the standard deviation value is 0.7 μW/m-3. The maximum values are associated with the acidic rocks in the northeast, southeast and a small portion in the northwest zones. About 68% of the readings are higher than the average RHP value in the area, thus Jabal Kharazah area can be considered as heat production area due to the relatively high radioactive mineral concentrations. There are excellent relationships between the derived RHP and the three radioactive elements, Uranium (eU), Thorium (eTh) and Potassium (K).

Measurement of Grain Production Efficiency in Main Grain-producing Areas and Analysis of Inter-provincial Differences--A Study Based on Super-SBM Model and Malmquist Index

China's food security mainly depends on the core areas of food production.Under the dual constraints of resource scarcity and environmental degradation,improving the grain production efficiency of the main grain-producing areas has become the fundamental way to strengthen the grain production capacity and improve the national food security capability,and to improve the efficiency of grain production in major grain-producing areas requires empirical support.This paper used the Super SBM model and the Malmquist index to measure the grain production efficiency of the main grain-producing areas from 2001 to 2020 from both static and dynamic perspectives,and compared the differences in grain production efficiency among different soil types and different provinces(autonomous regions)in the main grain-producing areas.The results showed that from 2001 to 2020,the grain production in the main grain-producing areas was in a relatively ineffective state,and the differences in grain production efficiency among different soil types and different provinces(autonomous regions)in the main grain-producing areas were obvious.The order of grain production efficiency in different soil types was black soil region>red-yellow soil region>paddy soil region>fluvo-aquic soil region,and the order of grain production efficiency of the provinces(autonomous regions)in the main grain-producing areas was Jilin>Heilongjiang>Inner Mongolia>Jiangxi>Hunan>Sichuan>Hubei>Jiangsu>Liaoning>Henan>Anhui>Shandong>Hebei.From 2001 to 2020,the total factor productivity of grain in the main grain-producing areas increased,but due to the trade-off between the technological progress and the growth of technical efficiency,the increase in the total factor productivity of grain in the main grain-producing areas was small,and the growth mainly came from the increase of input factors in this period.The total factor productivity of grain in Hebei,Heilongjiang,Liaoning,Jilin,Inner Mongolia,Shandong,Jiangsu,Henan and Anhui increased,but the increase was small,while the total factor productivity of grain in Jiangxi,Sichuan,Hunan and Hubei provinces declined.

Association between Agricultural Production Value and the Use of Rural Area within the Municipalities in the State of Sao Paulo, Brazil

Rural economic development can differ intensely among municipalities within the same region. The economic activity disparity among them makes public policy actions difficult. It is possible to find highly efficient and globally competitive producers, as well as those producing for subsistence, in the same area. This disparity stands out the total productivity importance of the factors of production in the agricultural sector, especially the productivity of the land. The way the land is occupied in the rural area, namely crops, pastures, reforestation and other areas, can be indicative of the productivity of the land factor and the value of agricultural production. The products that compose the value of the agricultural production present different land occupation through their own productive characteristic. The main objective of this work was to measure the association between the production value of groups of agricultural products and the diversified uses of the rural area in the production of the municipalities in the state of Sao Paulo. In this research, 52 agricultural products produced in 2008 were used, grouped in five production value variables and other nine variables of the land use in production of the municipalities in Sao Paulo. The multivariate statistical technique of canonical correlation was used to measure the association between the product variables group of the production value with the land use group in agricultural activities. It was concluded that there is a strong correlation （94.3%） in the first pair of canonical variables, representing the production value and the land use, allowing groups of municipalities to be formed at different stages of development in agricultural production. It can be verified that 61.8% of the municipalities in the state were below the average in the production group and land use and that only 4.8% were above average for the production variables group and with values below the average in land use. The stages of agricultural development in the municipalities of Sao Paulo and the association between the production and use of the area can contribute to identify the direction of public policies to increase the productivity of the agricultural sector.

Socio economic impact of vegetable production in Senegal:a case study of Niayes area

Vegetable production plays a very important role not only as a source of foreign exchange for Senegal and an appreciation of the dietary needs of populations,but also in the context of the policy of diversification.Thus the aim of this analysis is to measure the important economic impact and vegetable industrial actors,find the limited factors of the horticulture development and the perspectives for improving the vegetable production in the area.Our results show that the National production of fruits and vegetables is estimated approximately at 370,000 tons and the Niayes zone constitutes 80%of the domestic production.Horticulture is a sector which creates employments in that area with important incomes earned by both producers and the various intermediaries(commercial process) .The volume of exports has reached 14,321.588 tons in(2002-2003) against 11,125.132 tons in(2001-2002) witnessing than an increase of 28.7%,but the one of imports is very important and represents an outflow of foreign currency estimated at about 3 billion per year.

Content Determination of Total Flavonoids in Tetracera asiatica from 10 Different Production Areas in Guangxi

[Objectives] To determine the content of total flavonoids in Tetracera asiatica from different production areas in Guangxi and provide a basis for improving the quality standards of crude drug. [Methods] Using 50% ethanol as extractor,NaNO_2-Al(NO_3)_3-NaOH as chromogenic system and rutin as the reference substance,the content of total flavonoids from the crude drug was determined. [Results] A method for determining the content of total flavonoids was established,the content of total flavonoids was 11.35-21.35 mg·g^(-1),and the average content was 17.64 mg·g^(-1). [Conclusions] The method had high repeatability and stability,and the method was simple,rapid and sensitive and suitable for quantitative analysis.

Estimating the Efficiency of Summer Tomatoes Production: A Case Study in Borg El-Arab Area, Egypt

Tomatoes are one of the most popular and widely consumed vegetable crops worldwide. Egypt is characterized by its tomatoes production, whether for domestic use or export. Summer tomato farmers’ income has recently been reduced due to high production costs, particularly in new lands. As a result, the purpose of this research is to evaluate the economic efficiency of the elements used in summer tomato production in the Borg El-Arab area of Egypt as a new land. According to the findings, the summer tomato crop produced a reasonable profit for small-holding farmers in the study area. However, the elements are being used excessively in the production process, particularly seeds and fertilizers, resulting in increased production costs and failure to achieve economic efficiency of the elements used in the study area.