According to the meteorological data from Meteorological Station during 1961-2007 in Jiangxi Province,using the calculation method of production potential of climate recommended by Food and Agriculture Organization(FA...According to the meteorological data from Meteorological Station during 1961-2007 in Jiangxi Province,using the calculation method of production potential of climate recommended by Food and Agriculture Organization(FAO),the variation trends of climatic potential productivity of mid-season rice during this period were analyzed.The results indicated a trend of yearly decline in the variation of photosynthetic and light-temperature potential productivity in Jiangxi.The changes of climatic production potential fluctuated widely.The main reasons for the above-mentioned changes in recent years included more serious air pollution,resulting in less light and decline in photosynthetic potential productivity.An increase in extreme high-temperature days inhibited the growth of mid-season rice.The uneven distribution of precipitation resulted in the volatility of climatic production potential.To ensure high and stable yield,some counter-measures should be taken,including increasing weather modification input,building water conservancy facilities,enhancing the accuracy of weather forecasts and strengthening the research on climate changes.All the methods could solve those problems so as to ensure an improvement in rice production capacity to address climate change.展开更多
A gas production potential method for optimization of gas wellsite locations selection is proposed in terms of the coalbed gas resources volume and the recoverability. The method uses the actual data about reservoirs ...A gas production potential method for optimization of gas wellsite locations selection is proposed in terms of the coalbed gas resources volume and the recoverability. The method uses the actual data about reservoirs in a coalbed gas field in central China to optimize wellsite locations in the studied area in combination with the dynamic data about actual production in the coalbed gas field, selects a favorable subarea for gas wells deployment. The method is established based on the basic properties of coal reservoirs, in combination with the coalbed thickness and the gas content to make an analysis of the gas storage potential of a coal reservoir, as well as resources volume and the permeability of a coal reservoir. This method can be popularized for optimization of wellsite locations in other methane gas development areas or blocks.展开更多
The productivity exploitation degree,suitable exploitation degree and exploitable exploitation degree of production potential of winter wheat in three climate zones of Tianshui were calculated.The impacts of climate c...The productivity exploitation degree,suitable exploitation degree and exploitable exploitation degree of production potential of winter wheat in three climate zones of Tianshui were calculated.The impacts of climate changes on it were analyzed.The results showed the exploitation degree of production potential of winter wheat was still low in the north of Wei River,the valley of Wei River and the area of Guan Mountain in Tianshui,being 49.9%-60.0%.Both the suitable exploitation degree and exploitable exploitation degree of production potential of winter wheat were comparatively high,being 73.6%-78.7% and 18.7%-23.8% respectively.The sequencing was the north of Wei River>the valley of Wei River>the area of Guan Mountain.In the long run,it was of great potential to be excavated.The average temperature,sunshine hours for growth season of winter wheat had negative effects on exploitation degree,suitable exploitation degree and exploitable degree of production potential of winter wheat.The precipitation had the positive effect.And the temperature in the entire growth period,temperature in autumn,the sunshine in winter had remarkable negative effects on the exploitation degree of the production potential in Tianshui and the north of Wei River.The precipitation in the entire growth period,the precipitation in autumn had remarkable positive effects in Tianshui and each climate zones.And some moderate development countermeasures of regional production potential were proposed.展开更多
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...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.展开更多
The quantity and spatial pattern of farmland has changed in China, which has led to a major change in the production potential under the influence of the national project of eco- logical environmental protection and r...The quantity and spatial pattern of farmland has changed in China, which has led to a major change in the production potential under the influence of the national project of eco- logical environmental protection and rapid economic growth during 1990-2010. In this study, the production potential in China was calculated based on meteorological, terrain elevation, soil and land-use data from 1990, 2000 and 2010 using the Global Agro-ecological Zones model. Then, changes in the production potential in response to farmland changes from 1990 to 2010 were subsequently analyzed. The main conclusions were the following. First, the total production potential was 1.055 billion tons in China in 2010. Moreover, the average produc- tion potential was 7614 kg/ha and showed tremendous heterogeneity in spatial pattern. Total production in eastern China was high, whereas that in northwestern China was low. The regions with high per unit production potential were mainly distributed over southern China and the middle and lower reaches of the Yangtze River. Second, the obvious spatiotemporal het- erogeneity in farmland changes from 1990 to 2010 had a significant influence on the produc- tion potential in China. The total production potential decreased in southern China and in- creased in northern China. Furthermore, the center of growth of the production potential moved gradually from northeastern China to northwestern China. The net decrease in the production potential was 2.97 million tons, which occupied 0.29% of the national total actual production in 2010. Third, obvious differences in the production potential in response to farmland changes from 1990 to 2000 and from 2000 to 2010 were detected. The net increase in the production potential during the first decade was 10.11 million tons and mainly distrib- uted in the Northeast China Plain and the arid and semi-arid regions of northern China. The net decrease in the production potential during the next decade was 13.08 million tons and primarily distributed in the middle and lower reaches of the Yangtze River region and the Huang-Huai-Hai Plain. In general, the reason for the increase in the production potential during the past two decades might be due to the reclamation of grasslands, woodlands and unused land, and the reason for the decrease in the production potential might be urbanization that occupied the farmland and Green for Grain Project, which returned farmland to forests and grasslands.展开更多
This study was aimed to determine biogas amount and the energy value which could be made from animal manure in Turkey.For this purpose,biogas potential was calculated with the number of dairy cattle and laying hens ta...This study was aimed to determine biogas amount and the energy value which could be made from animal manure in Turkey.For this purpose,biogas potential was calculated with the number of dairy cattle and laying hens taking into consideration,which have high availability manure.Turkey has a total of about 8.9 million dairy cattle and 98 million laying hens.Annual total 92.1 million tons of manure is obtained from these animals.There are 89.2 million tons of cattle manure and 2.9 million tons of laying hens manure.Annual 1.6 billion m3 of biogas can be produced from the usable amount of this manure.The heating value of biogas produced from this manure is about 36.7 PJ.These values can provide 1.1%of Turkey’s annual energy consumption(80.5 Mtoe).The distribution of these calculated data by province was mapped using a GIS Software’s mapping option.When provinces are ranked according to the amount of biogas production,the top 10 are Konya,Erzurum,İzmir,Balıkesir,Kars,Afyon,Diyarbakır,Aydın,Ankara and Ağrı.Furthermore,the greenhouse gas(GHG)emission abatement was calculated for demonstrating the environmental benefits of the biogas production from animal manure.It was determined that the CO2 emission abatement annually ranging between 17.2-25.3 million tons could be provided with the evaluation of biogas potential which was calculated.展开更多
The changes in utilization of agricultural land have gradually grown into one of the major factors impacting grain output in China. This study explores the various components of agricultural production in China from t...The changes in utilization of agricultural land have gradually grown into one of the major factors impacting grain output in China. This study explores the various components of agricultural production in China from the land utilization perspective, involving changes in grain production per unit area, multi-cropping index, and adjustment of agricultural structure. Compared with the record values, different research methodologies are used to analyze the po- tential of above three components. The results indicate that grain production potential of 65.68×109kg was unexploited in 2006, in which 45.8×109kg came from the restructuring in agriculture. So we can infer that the reduction of grain production in China could be primarily attributed to agricultural restructuring in recent years. So the productive poten- tial can be fully restored by increasing agricultural investment, or recovering agricultural structure in favorable condi- tions. So we can say that China’s current condition of food security is good.展开更多
The article established the HDRICE model by modifying the structure of the ORYZA1 model and revising its parameters by field experiments. The HDRICE model consists of the modules of morphological development of rice, ...The article established the HDRICE model by modifying the structure of the ORYZA1 model and revising its parameters by field experiments. The HDRICE model consists of the modules of morphological development of rice, daily dry matter accumulation and partitioning, daily CO2 assimilation of the canopy, leaf area, and tiller development. The model preferably simulated the dynamic rice development because of the thorough integration of the effects of temperature and light on the rates of rice development, photosynthesis, respiration, and. other ecophysiological processes. In addition, this model has attainable grain yield in the test experiment that showed the potential yield of cultivar Xieyou 46 ranged from 11 to 13 tons ha-~. Besides, the model was used to optimize the combinations of the transplanting date, seedling age and density for cultivar Xieyou 46 at Jinhua area, and the population quantitative indices to attain the potential yield such as maximum stems, effective panicles, filled grain number/leaf area, and so on. The result showed that the combination of transplanting date on July 25, seedling age of 35 days and base seedling density of 1.33 x 106ha-1 is the optimum combination for the second hybrid rice production in Jinhua County, China. And the maximum stems, the effective panicles, the filled grain per panicle, the peak of optimum LAI, LAI in later filling stage, and the filled grain number/leaf were 6.03×10^6ha, 3.99×10^6ha, 119.2, 8.59, 5-6, and 0.64, respectively.展开更多
In the face of global warming and increasing impervious surfaces,quantifying the change of climate potential productivity(CPP)is of great significance for the food production planning.Targeting the Dongting Lake Basin...In the face of global warming and increasing impervious surfaces,quantifying the change of climate potential productivity(CPP)is of great significance for the food production planning.Targeting the Dongting Lake Basin,which is a key area for food production in China,this paper uses meteorological data,as well as Climate Change Initiative Land Cover,and Shuttle Radar Topography Mission digital elevation model to investigate the CPP and its changes from 2000 to 2020.The suitability of land for cultivation(SLC),and the land use/land cover change(LUCC)are also considered.The results showed that the CPP varied from 9,825 to 20,895 kg ha^(-1).Even though the newly added impervious surfaces indirectly resulted in the decrease of CPP by of 9.81×10~8 kg,overall,the CPP increased at an average rate of 83.7 kg ha^(-1)a^(-1).Global warming is the strongest driver behind CPP increase,and CPP has played an important role in the conversions between cultivated land and other land types.The structure of land types tends to be optimized against this challenge.展开更多
The Java-Sumatra upwelling is one of the most important upwelling systems in the Indian Ocean, with maximum upwelling intensity in July through August. To estimate the nitrate supplied by upwelling, we developed a thr...The Java-Sumatra upwelling is one of the most important upwelling systems in the Indian Ocean, with maximum upwelling intensity in July through August. To estimate the nitrate supplied by upwelling, we developed a three-dimensional hydrodynamic model to calculate the mean vertical speed and determine the depth of upwelling. We used in-situ vertical nitrate profiles to assess nitrate concentration in the upwelled waters, and calculated the nitrate supply as the product of nitrate concentration and vertical transport obtained from the numerical model. The calculated result represents potential new production generated in the upwelling region. We found that on the event time scale (monthly) of Java-Sumatra upwelling, water brought to the surface originated from locations 100-m deep, giving a nitrate supply of 93.77×10 3mol/s and potential new production of 1.02×10 14gC/a.展开更多
The objective of this study is to identify and collect information on local agriculture products and identify local potential agriculture and livestock that can attract foreign investments. Used Stratified Random Samp...The objective of this study is to identify and collect information on local agriculture products and identify local potential agriculture and livestock that can attract foreign investments. Used Stratified Random Sampling and data was collected from both primary and secondary data (both quantitative and qualitative data. The data analyzed used qualitative and quantitative analysis. The supply chain analysis was carried out to develop a description of the value chain to identify potential high-value market areas and current and potential products in the domestic and export markets. The results of the study revealed that most farmers in the research location grow different types of crops and livestock. In particular for Aileu and Ainaro where most of the areas are up-land, therefore, horticulture crops (mustard, cabbage, carrots, and tomato) and coffee are dominated in these areas. For Manufahi, some parts are lowland areas, where most crops grown are maize, cassava, and paddy rice. The study reveals that local potential agriculture products and livestock in the municipalities of Aileu, Ainaro, and Manufahi are vegetable, coffee, maize, and paddy rice, banana, shallot, tangerine, cabbage, carrot, cattle, mung-bean, and banana. To accelerate economic growth, in these municipalities, there is a need to modernize agricultural production, requiring markets for both inputs supply and for the sale of output products. Opportunities to increase the productivity of these products are feasible and this can be done through the use of high-variety seeds and better farm management, and the government and private sector can play an important role in improving productivity as this will have a further implication in improving food security.展开更多
To evaluate scientifically the change of photosynthetic and thermal potential productivity caused by climate variation,based on comparison with mean of previous 30 years(1971-2000),the change of total solar radiation,...To evaluate scientifically the change of photosynthetic and thermal potential productivity caused by climate variation,based on comparison with mean of previous 30 years(1971-2000),the change of total solar radiation,sunshine hours,photosynthetic active radiation,photosynthetic and thermal potential productivity since 2001 were analyzed through data of radiation,sunshine and temperature in Shandong Province from 1971 to 2007,and the change trend was also tested by Mann-Kendall non-parametric statistical met...展开更多
[Objective] The paper was scientifically evaluate the potential fishery productivity of Lihu using GIS technology.[Method] The evaluation of potential fishery productivity in Lihu was based on GIS and AHP according to...[Objective] The paper was scientifically evaluate the potential fishery productivity of Lihu using GIS technology.[Method] The evaluation of potential fishery productivity in Lihu was based on GIS and AHP according to the characteristics of fisheries resources in Lihu Lake.The evaluation system included 3 sub-models including water quality,biodiversity and hydrological condition,which totally had 10 indexes.Judgment matrix was constructed based the advices of professors of fisheries resources,and the indicator’s weight were calculated by the process of AHP.The ranking distributing map of potential fishery productivity in Lihu was obtained by the model of raster analysis,raster calculator,spatial overlay and classification models of ARC/INFO.[Result] Potential fishery productivity of Lihu was divided into 4 grades in term of higher,high,general and low,and which covered 2.643 3,3.844 8,1.121 4 and 0.400 5 hm2,respectively.[Conclusion] The study provided theoretical basis for ecological reconstruction of Lihu Lake.展开更多
Coalbed methane(CBM) resources in No.15 coal seam of Taiyuan Formation account for 55% of the total CBM resources in southern Qinshui Basin(SQB), and have a great production potential. This study aims at investigating...Coalbed methane(CBM) resources in No.15 coal seam of Taiyuan Formation account for 55% of the total CBM resources in southern Qinshui Basin(SQB), and have a great production potential. This study aims at investigating the CBM production in No.15 coal seam and its influence factors. Based on a series of laboratory experiments and latest exploration and development data from local coal mines and CBM companies, the spatial characteristics of gas production of No.15 coal seam were analyzed and then the influences of seven factors on the gas productivity of this coal seam were discussed, including coal thickness, burial depth, gas content, ratio of critical desorption pressure to original coal reservoir pressure(RCPOP), porosity, permeability, and hydrogeological condition. The influences of hydrological condition on CBM production were analyzed based on the discussions of four aspects: hydrogeochemistry, roof lithology and its distribution, hydrodynamic field of groundwater, and recharge rate of groundwater. Finally, a three-level analytic hierarchy process(AHP) evaluation model was proposed for predicting the CBM potentials of the No.15 coal seam in the SQB. The best prospective target area for CBM production of the No.15 coal seam is predicted to be in the districts of Panzhuang, Chengzhuang and south of Hudi.展开更多
The key zones of returning farmland to forestland and grassland in Ningxia were studied. By using the "stepwise revised method",the climate productive potential,light and temperature productive potential in the zone...The key zones of returning farmland to forestland and grassland in Ningxia were studied. By using the "stepwise revised method",the climate productive potential,light and temperature productive potential in the zone in recent 50 years were counted. The light and temperature productive potential of corn in Ningxia irrigated area,the central arid zone and the southern mountain area presented the linear increase trend. But when considered the climate productive potentials of light,temperature and water,the numerical value was very low because of the scarce rainfall,and no agriculture without the irrigation. The light and temperature productive potential,climate productive potential of winter wheat in the central arid zone had no significant trend,but the variation range of climate productive potential was very big. The light and temperature productive potential of winter wheat in the southern mountain area had no significant variation trend,and the climate productive potential presented the weak decline trend. It illustrated that the productive of winter wheat was greatly restricted by the water content. By using the meteorological factor data which were simulated by RegCM3-WOFOST/LINGRA coupled model,the future climate productive potentials of winter wheat in the central south of Ningxia was counted. They both presented the weak increase trend. It illustrated that the climate in Ningxia was favorable to improve the yield of winter wheat after returning farmland to forestland.展开更多
Forest Potential Productivity (FPP) of 8 counties in Tianshan was cal culated, and the potential timber output of these counties was analyzed with Mia mi Model and Thornthwaite Memorial Model. Research results showed ...Forest Potential Productivity (FPP) of 8 counties in Tianshan was cal culated, and the potential timber output of these counties was analyzed with Mia mi Model and Thornthwaite Memorial Model. Research results showed that annual av erage output of present stand in Tianshan Forest Region was 3.7 m3/(hm2. a), whi ch reached only 49% of average FPP.展开更多
Despite the improvement in cultivar characters and management practices, large gaps between the attainable and potential yields still exist in winter wheat of China. Quantifying the crop potential yield is essential f...Despite the improvement in cultivar characters and management practices, large gaps between the attainable and potential yields still exist in winter wheat of China. Quantifying the crop potential yield is essential for estimating the food production capacity and improving agricultural policies to ensure food security. Gradually descending models and geographic infor- mation system (GIS) technology were employed to characterize the spatial variability of potential yields and yield gaps in winter wheat across the main production region of China. The results showed that during 2000-2010, the average potential yield limited by thermal resource (YGT) was 23.2 Mg ha-1, with larger value in the northern area relative to the southern area. The potential yield limited by the water supply (YGw) generally decreased from north to south, with an average value of 1.9 Mg ha-1 across the entire study region. The highest YGw in the north sub-region (NS) implied that the irrigation and drainage conditions in this sub-region must be improved. The averaged yield loss of winter wheat from nutrient deficiency (YGH) varied between 2.1 and 3.1 Mg ha-1 in the study area, which was greater than the yield loss caused by water limitation. The potential decrease in yield from photo-thermal-water-nutrient-limited production to actual yield (YGo) was over 6.0 Mg ha-1, ranging from 4.9 to 8.3 Mg ha^-1 across the entire study region, and it was more obvious in the southern area than in the northern area. These findings suggest that across the main winter wheat production region, the highest yield gap was induced by thermal resources, followed by other factors, such as the level of farming technology, social policy and economic feasibility. Furthermore, there are opportunities to narrow the yield gaps by making full use of climatic resources and developing a reasonable production plan for winter wheat crops. Thus, meeting the challenges of food security and sustainability in the coming decades is possible but will require considerable changes in water and nutrient management and socio-economic policies.展开更多
There are more people but less land in China,so food safety has always been a most important issue government concerned.With continuous population increase,economic development and environment protection,cropland occu...There are more people but less land in China,so food safety has always been a most important issue government concerned.With continuous population increase,economic development and environment protection,cropland occupation and supplement are unavoidable.It not only leads to the variation of cropland area,but also makes the light-temperature potential productivity per unit area different due to regional climate differentiation,therefore impacts the total potential productivity and food output eventually.So,it is necessary to analyze the climate differentiation between occupation and supplement cropland areas and to study its impact on total potential productivity,which is significant to reasonably develop natural resources and instruct agricultural arrangement.This study firstly discussed the variation and distribution of occupation and supplement croplands in China from 2000 to 2008,then analyzed the climate differentiation between occupation and supplement cropland areas and its effect on light-temperature potential productivity.The results demonstrate:1) From 2000 to 2008,the cropland variation presented occupation in the south and supplement in the north,but overall decreased.Supplement cropland was mainly from ecological reclamation(77.78%) and was mainly distributed in Northeast China and Northwest China with poor climatic and natural conditions.Occupation cropland was mainly used for construction(52.88%) and ecological restoration(44.78%) purposes,and was mainly distributed in the Huang-Huai-Hai Plain,and the middle and lower reaches of the Changjiang(Yangtze) River with better climatic and natural conditions.2) The climate conditions were quite different in supplement and occupation cropland areas.The annual precipitation,annual accumulated temperature and average annual temperature were lower in the supplement cropland area,and its average po-tential productivity per unit was only 62% of occupation cropland area,which was the main reason for the decrease of total potential productivity.3) Cropland occupation and supplement led to the variation of total potential productivity and its spatial distribution.The productivity decreased in the south and increased in the north,but had a net loss of 4.38315×107 t in the whole country.The increase of cropland area was at the cost of reclaiming natural forest and grassland resources,and destroying natural ecological environment,while the decrease of cropland area was mainly due to a lot of cropland occupied by urban-rural construction,which threatened the sustainable use of cropland resources.展开更多
Value analysis of grain production influencing factors is a complex decision problem. This paper introduced a modified Analytic Hierarchy Process (AHP) accumulation factor, namely Solving Weight by AHP's Accumulati...Value analysis of grain production influencing factors is a complex decision problem. This paper introduced a modified Analytic Hierarchy Process (AHP) accumulation factor, namely Solving Weight by AHP's Accumulation Factor Sequence Evaluating Data. We used the arithmetical average to replace the expert marking, so that the possible decision mistakes by the subjective judgments could be avoided. We computed the case with this method, which obtained attribute value of 17 influencing factors of the potential food production in Heilongjiang Province, and the result of which was reasonable展开更多
Climate warming is expected to influence forest growth,composition and distribution.However,accurately estimating and predicting forest biomass,potential productivity or forest growth is still a challenge for forest m...Climate warming is expected to influence forest growth,composition and distribution.However,accurately estimating and predicting forest biomass,potential productivity or forest growth is still a challenge for forest managers dealing with land-use at the stand to regional levels.In the present study,we predicted the potential productivity(PP)of forest under current and future climate scenarios(RCP2.6,RCP4.5,RCP6.0 and RCP8.5)in Jilin province,northeastern China by using Paterson’s Climate Vegetation and Productivity(CVP)index model.The PP was validated by comparing it with the mean and maximum net primary production calculated from light energy utilization(GLM_PEM).Our results indicated that using the CVP index model is partially valid for predicting the potential forest productivity in northeastern China.PP exhibited obvious spatial heterogeneity varying from 4.6 to 8.9 m3 ha-1 year-1 with an increasing tendency from northwest to southeast driven by the precipitation across the region.The number of vegetation-active months,precipitation and insolation coefficient were identified as the primary factors affecting PP,but no significant relationship was found for warmest temperature or temperature fluctuation.Under future climate scenarios,PP across the Jilin Province is expected to increase from 1.38%(RCP2.6 in 2050)to 15.30%(RCP8.5 in 2070),especially in the eastern Songnen Plain(SE)for the RCP8.5 scenarios.展开更多
文摘According to the meteorological data from Meteorological Station during 1961-2007 in Jiangxi Province,using the calculation method of production potential of climate recommended by Food and Agriculture Organization(FAO),the variation trends of climatic potential productivity of mid-season rice during this period were analyzed.The results indicated a trend of yearly decline in the variation of photosynthetic and light-temperature potential productivity in Jiangxi.The changes of climatic production potential fluctuated widely.The main reasons for the above-mentioned changes in recent years included more serious air pollution,resulting in less light and decline in photosynthetic potential productivity.An increase in extreme high-temperature days inhibited the growth of mid-season rice.The uneven distribution of precipitation resulted in the volatility of climatic production potential.To ensure high and stable yield,some counter-measures should be taken,including increasing weather modification input,building water conservancy facilities,enhancing the accuracy of weather forecasts and strengthening the research on climate changes.All the methods could solve those problems so as to ensure an improvement in rice production capacity to address climate change.
文摘A gas production potential method for optimization of gas wellsite locations selection is proposed in terms of the coalbed gas resources volume and the recoverability. The method uses the actual data about reservoirs in a coalbed gas field in central China to optimize wellsite locations in the studied area in combination with the dynamic data about actual production in the coalbed gas field, selects a favorable subarea for gas wells deployment. The method is established based on the basic properties of coal reservoirs, in combination with the coalbed thickness and the gas content to make an analysis of the gas storage potential of a coal reservoir, as well as resources volume and the permeability of a coal reservoir. This method can be popularized for optimization of wellsite locations in other methane gas development areas or blocks.
文摘The productivity exploitation degree,suitable exploitation degree and exploitable exploitation degree of production potential of winter wheat in three climate zones of Tianshui were calculated.The impacts of climate changes on it were analyzed.The results showed the exploitation degree of production potential of winter wheat was still low in the north of Wei River,the valley of Wei River and the area of Guan Mountain in Tianshui,being 49.9%-60.0%.Both the suitable exploitation degree and exploitable exploitation degree of production potential of winter wheat were comparatively high,being 73.6%-78.7% and 18.7%-23.8% respectively.The sequencing was the north of Wei River>the valley of Wei River>the area of Guan Mountain.In the long run,it was of great potential to be excavated.The average temperature,sunshine hours for growth season of winter wheat had negative effects on exploitation degree,suitable exploitation degree and exploitable degree of production potential of winter wheat.The precipitation had the positive effect.And the temperature in the entire growth period,temperature in autumn,the sunshine in winter had remarkable negative effects on the exploitation degree of the production potential in Tianshui and the north of Wei River.The precipitation in the entire growth period,the precipitation in autumn had remarkable positive effects in Tianshui and each climate zones.And some moderate development countermeasures of regional production potential were proposed.
基金Supported by Operation and Improvement Program of Climate Monitoring,Warning and Assessment Services in Three Gorges Reservoir AreaNational Key Technology R&D Program (2007BAC29B06)+1 种基金Major State Basic Research Development 973 Program (2006CB400503)National Natural Science Foundation of China (40705031)
文摘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.
基金National Key Project of Scientific and Technical Supporting Programs,No.2013BAC03B01Project of CAS Action-plan for West Development,No.KZCX2-XB3-08-01Important National Project of High-resolution Earth Observation System,No.05-Y30B02-9001-13/15-10
文摘The quantity and spatial pattern of farmland has changed in China, which has led to a major change in the production potential under the influence of the national project of eco- logical environmental protection and rapid economic growth during 1990-2010. In this study, the production potential in China was calculated based on meteorological, terrain elevation, soil and land-use data from 1990, 2000 and 2010 using the Global Agro-ecological Zones model. Then, changes in the production potential in response to farmland changes from 1990 to 2010 were subsequently analyzed. The main conclusions were the following. First, the total production potential was 1.055 billion tons in China in 2010. Moreover, the average produc- tion potential was 7614 kg/ha and showed tremendous heterogeneity in spatial pattern. Total production in eastern China was high, whereas that in northwestern China was low. The regions with high per unit production potential were mainly distributed over southern China and the middle and lower reaches of the Yangtze River. Second, the obvious spatiotemporal het- erogeneity in farmland changes from 1990 to 2010 had a significant influence on the produc- tion potential in China. The total production potential decreased in southern China and in- creased in northern China. Furthermore, the center of growth of the production potential moved gradually from northeastern China to northwestern China. The net decrease in the production potential was 2.97 million tons, which occupied 0.29% of the national total actual production in 2010. Third, obvious differences in the production potential in response to farmland changes from 1990 to 2000 and from 2000 to 2010 were detected. The net increase in the production potential during the first decade was 10.11 million tons and mainly distrib- uted in the Northeast China Plain and the arid and semi-arid regions of northern China. The net decrease in the production potential during the next decade was 13.08 million tons and primarily distributed in the middle and lower reaches of the Yangtze River region and the Huang-Huai-Hai Plain. In general, the reason for the increase in the production potential during the past two decades might be due to the reclamation of grasslands, woodlands and unused land, and the reason for the decrease in the production potential might be urbanization that occupied the farmland and Green for Grain Project, which returned farmland to forests and grasslands.
文摘This study was aimed to determine biogas amount and the energy value which could be made from animal manure in Turkey.For this purpose,biogas potential was calculated with the number of dairy cattle and laying hens taking into consideration,which have high availability manure.Turkey has a total of about 8.9 million dairy cattle and 98 million laying hens.Annual total 92.1 million tons of manure is obtained from these animals.There are 89.2 million tons of cattle manure and 2.9 million tons of laying hens manure.Annual 1.6 billion m3 of biogas can be produced from the usable amount of this manure.The heating value of biogas produced from this manure is about 36.7 PJ.These values can provide 1.1%of Turkey’s annual energy consumption(80.5 Mtoe).The distribution of these calculated data by province was mapped using a GIS Software’s mapping option.When provinces are ranked according to the amount of biogas production,the top 10 are Konya,Erzurum,İzmir,Balıkesir,Kars,Afyon,Diyarbakır,Aydın,Ankara and Ağrı.Furthermore,the greenhouse gas(GHG)emission abatement was calculated for demonstrating the environmental benefits of the biogas production from animal manure.It was determined that the CO2 emission abatement annually ranging between 17.2-25.3 million tons could be provided with the evaluation of biogas potential which was calculated.
基金Under the auspices of National Key Technologies R&D Program of China (No. 2006BAB15B02)National Natural Science Foundation of China (No. 40671009)
文摘The changes in utilization of agricultural land have gradually grown into one of the major factors impacting grain output in China. This study explores the various components of agricultural production in China from the land utilization perspective, involving changes in grain production per unit area, multi-cropping index, and adjustment of agricultural structure. Compared with the record values, different research methodologies are used to analyze the po- tential of above three components. The results indicate that grain production potential of 65.68×109kg was unexploited in 2006, in which 45.8×109kg came from the restructuring in agriculture. So we can infer that the reduction of grain production in China could be primarily attributed to agricultural restructuring in recent years. So the productive poten- tial can be fully restored by increasing agricultural investment, or recovering agricultural structure in favorable condi- tions. So we can say that China’s current condition of food security is good.
基金supported by the National Natural Science Foundation of China(69673044).
文摘The article established the HDRICE model by modifying the structure of the ORYZA1 model and revising its parameters by field experiments. The HDRICE model consists of the modules of morphological development of rice, daily dry matter accumulation and partitioning, daily CO2 assimilation of the canopy, leaf area, and tiller development. The model preferably simulated the dynamic rice development because of the thorough integration of the effects of temperature and light on the rates of rice development, photosynthesis, respiration, and. other ecophysiological processes. In addition, this model has attainable grain yield in the test experiment that showed the potential yield of cultivar Xieyou 46 ranged from 11 to 13 tons ha-~. Besides, the model was used to optimize the combinations of the transplanting date, seedling age and density for cultivar Xieyou 46 at Jinhua area, and the population quantitative indices to attain the potential yield such as maximum stems, effective panicles, filled grain number/leaf area, and so on. The result showed that the combination of transplanting date on July 25, seedling age of 35 days and base seedling density of 1.33 x 106ha-1 is the optimum combination for the second hybrid rice production in Jinhua County, China. And the maximum stems, the effective panicles, the filled grain per panicle, the peak of optimum LAI, LAI in later filling stage, and the filled grain number/leaf were 6.03×10^6ha, 3.99×10^6ha, 119.2, 8.59, 5-6, and 0.64, respectively.
基金funded by the National Natural Science Foundation of China(Grant No.72174211)the Natural Science Foundation of Hunan Province(Grant No.2023JJ30693)。
文摘In the face of global warming and increasing impervious surfaces,quantifying the change of climate potential productivity(CPP)is of great significance for the food production planning.Targeting the Dongting Lake Basin,which is a key area for food production in China,this paper uses meteorological data,as well as Climate Change Initiative Land Cover,and Shuttle Radar Topography Mission digital elevation model to investigate the CPP and its changes from 2000 to 2020.The suitability of land for cultivation(SLC),and the land use/land cover change(LUCC)are also considered.The results showed that the CPP varied from 9,825 to 20,895 kg ha^(-1).Even though the newly added impervious surfaces indirectly resulted in the decrease of CPP by of 9.81×10~8 kg,overall,the CPP increased at an average rate of 83.7 kg ha^(-1)a^(-1).Global warming is the strongest driver behind CPP increase,and CPP has played an important role in the conversions between cultivated land and other land types.The structure of land types tends to be optimized against this challenge.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (Nos. KZCX2-YW-Q11-02, LYQY200807)the National Natural Science Foundation of China (No. 40876093)
文摘The Java-Sumatra upwelling is one of the most important upwelling systems in the Indian Ocean, with maximum upwelling intensity in July through August. To estimate the nitrate supplied by upwelling, we developed a three-dimensional hydrodynamic model to calculate the mean vertical speed and determine the depth of upwelling. We used in-situ vertical nitrate profiles to assess nitrate concentration in the upwelled waters, and calculated the nitrate supply as the product of nitrate concentration and vertical transport obtained from the numerical model. The calculated result represents potential new production generated in the upwelling region. We found that on the event time scale (monthly) of Java-Sumatra upwelling, water brought to the surface originated from locations 100-m deep, giving a nitrate supply of 93.77×10 3mol/s and potential new production of 1.02×10 14gC/a.
文摘The objective of this study is to identify and collect information on local agriculture products and identify local potential agriculture and livestock that can attract foreign investments. Used Stratified Random Sampling and data was collected from both primary and secondary data (both quantitative and qualitative data. The data analyzed used qualitative and quantitative analysis. The supply chain analysis was carried out to develop a description of the value chain to identify potential high-value market areas and current and potential products in the domestic and export markets. The results of the study revealed that most farmers in the research location grow different types of crops and livestock. In particular for Aileu and Ainaro where most of the areas are up-land, therefore, horticulture crops (mustard, cabbage, carrots, and tomato) and coffee are dominated in these areas. For Manufahi, some parts are lowland areas, where most crops grown are maize, cassava, and paddy rice. The study reveals that local potential agriculture products and livestock in the municipalities of Aileu, Ainaro, and Manufahi are vegetable, coffee, maize, and paddy rice, banana, shallot, tangerine, cabbage, carrot, cattle, mung-bean, and banana. To accelerate economic growth, in these municipalities, there is a need to modernize agricultural production, requiring markets for both inputs supply and for the sale of output products. Opportunities to increase the productivity of these products are feasible and this can be done through the use of high-variety seeds and better farm management, and the government and private sector can play an important role in improving productivity as this will have a further implication in improving food security.
基金Supported by Special Project of China Meteorological Administrationon Effects of Climate Change on Solar Energy in East ChinaSpecial fund of Meteorological Science and Technology Services inShandong Province in 2006~~
文摘To evaluate scientifically the change of photosynthetic and thermal potential productivity caused by climate variation,based on comparison with mean of previous 30 years(1971-2000),the change of total solar radiation,sunshine hours,photosynthetic active radiation,photosynthetic and thermal potential productivity since 2001 were analyzed through data of radiation,sunshine and temperature in Shandong Province from 1971 to 2007,and the change trend was also tested by Mann-Kendall non-parametric statistical met...
基金Special Funds for Basic Research and Operating Expenses of Central Nonprofit Research Institutes(2011JBFC04)Special Research Project of Public Service Sectors(agriculture)(200903048-03)Special Finance of Department of Agriculture(6125005)~~
文摘[Objective] The paper was scientifically evaluate the potential fishery productivity of Lihu using GIS technology.[Method] The evaluation of potential fishery productivity in Lihu was based on GIS and AHP according to the characteristics of fisheries resources in Lihu Lake.The evaluation system included 3 sub-models including water quality,biodiversity and hydrological condition,which totally had 10 indexes.Judgment matrix was constructed based the advices of professors of fisheries resources,and the indicator’s weight were calculated by the process of AHP.The ranking distributing map of potential fishery productivity in Lihu was obtained by the model of raster analysis,raster calculator,spatial overlay and classification models of ARC/INFO.[Result] Potential fishery productivity of Lihu was divided into 4 grades in term of higher,high,general and low,and which covered 2.643 3,3.844 8,1.121 4 and 0.400 5 hm2,respectively.[Conclusion] The study provided theoretical basis for ecological reconstruction of Lihu Lake.
基金financially supported by the Natural Science Foundation of China (No.41802192)the National Science and Technology Key Special Project of China (No.2016ZX05044-002 and No.2016ZX05043)+2 种基金the Shanxi Provincial Basic Research Program-Coal Bed Methane Joint Research Foundation (No.2012012001 and No.2015012014)Open Fund of State Key Laboratory of Water Resource Protection and Utilization in Coal Mining (No.SHJT-17-42.18)the Fundamental Research Funds for the Central Universities (No.CUGL170811)
文摘Coalbed methane(CBM) resources in No.15 coal seam of Taiyuan Formation account for 55% of the total CBM resources in southern Qinshui Basin(SQB), and have a great production potential. This study aims at investigating the CBM production in No.15 coal seam and its influence factors. Based on a series of laboratory experiments and latest exploration and development data from local coal mines and CBM companies, the spatial characteristics of gas production of No.15 coal seam were analyzed and then the influences of seven factors on the gas productivity of this coal seam were discussed, including coal thickness, burial depth, gas content, ratio of critical desorption pressure to original coal reservoir pressure(RCPOP), porosity, permeability, and hydrogeological condition. The influences of hydrological condition on CBM production were analyzed based on the discussions of four aspects: hydrogeochemistry, roof lithology and its distribution, hydrodynamic field of groundwater, and recharge rate of groundwater. Finally, a three-level analytic hierarchy process(AHP) evaluation model was proposed for predicting the CBM potentials of the No.15 coal seam in the SQB. The best prospective target area for CBM production of the No.15 coal seam is predicted to be in the districts of Panzhuang, Chengzhuang and south of Hudi.
基金Supported by the National Natural Science Fund Item (40675071)~~
文摘The key zones of returning farmland to forestland and grassland in Ningxia were studied. By using the "stepwise revised method",the climate productive potential,light and temperature productive potential in the zone in recent 50 years were counted. The light and temperature productive potential of corn in Ningxia irrigated area,the central arid zone and the southern mountain area presented the linear increase trend. But when considered the climate productive potentials of light,temperature and water,the numerical value was very low because of the scarce rainfall,and no agriculture without the irrigation. The light and temperature productive potential,climate productive potential of winter wheat in the central arid zone had no significant trend,but the variation range of climate productive potential was very big. The light and temperature productive potential of winter wheat in the southern mountain area had no significant variation trend,and the climate productive potential presented the weak decline trend. It illustrated that the productive of winter wheat was greatly restricted by the water content. By using the meteorological factor data which were simulated by RegCM3-WOFOST/LINGRA coupled model,the future climate productive potentials of winter wheat in the central south of Ningxia was counted. They both presented the weak increase trend. It illustrated that the climate in Ningxia was favorable to improve the yield of winter wheat after returning farmland to forestland.
文摘Forest Potential Productivity (FPP) of 8 counties in Tianshan was cal culated, and the potential timber output of these counties was analyzed with Mia mi Model and Thornthwaite Memorial Model. Research results showed that annual av erage output of present stand in Tianshan Forest Region was 3.7 m3/(hm2. a), whi ch reached only 49% of average FPP.
基金supported by the National High-Tech R&D Program of China(863 Program,2013AA100404)the National Natural Science Foundation of China(31301234 and 31271616)+1 种基金the National Research Foundation for the Doctoral Program of Higher Education of China(20120097110042)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China(PAPD)
文摘Despite the improvement in cultivar characters and management practices, large gaps between the attainable and potential yields still exist in winter wheat of China. Quantifying the crop potential yield is essential for estimating the food production capacity and improving agricultural policies to ensure food security. Gradually descending models and geographic infor- mation system (GIS) technology were employed to characterize the spatial variability of potential yields and yield gaps in winter wheat across the main production region of China. The results showed that during 2000-2010, the average potential yield limited by thermal resource (YGT) was 23.2 Mg ha-1, with larger value in the northern area relative to the southern area. The potential yield limited by the water supply (YGw) generally decreased from north to south, with an average value of 1.9 Mg ha-1 across the entire study region. The highest YGw in the north sub-region (NS) implied that the irrigation and drainage conditions in this sub-region must be improved. The averaged yield loss of winter wheat from nutrient deficiency (YGH) varied between 2.1 and 3.1 Mg ha-1 in the study area, which was greater than the yield loss caused by water limitation. The potential decrease in yield from photo-thermal-water-nutrient-limited production to actual yield (YGo) was over 6.0 Mg ha-1, ranging from 4.9 to 8.3 Mg ha^-1 across the entire study region, and it was more obvious in the southern area than in the northern area. These findings suggest that across the main winter wheat production region, the highest yield gap was induced by thermal resources, followed by other factors, such as the level of farming technology, social policy and economic feasibility. Furthermore, there are opportunities to narrow the yield gaps by making full use of climatic resources and developing a reasonable production plan for winter wheat crops. Thus, meeting the challenges of food security and sustainability in the coming decades is possible but will require considerable changes in water and nutrient management and socio-economic policies.
基金Under the auspices of Knowledge Innovation Programs of Chinese Academy of Sciences (No KSCX1-YW-09-01)
文摘There are more people but less land in China,so food safety has always been a most important issue government concerned.With continuous population increase,economic development and environment protection,cropland occupation and supplement are unavoidable.It not only leads to the variation of cropland area,but also makes the light-temperature potential productivity per unit area different due to regional climate differentiation,therefore impacts the total potential productivity and food output eventually.So,it is necessary to analyze the climate differentiation between occupation and supplement cropland areas and to study its impact on total potential productivity,which is significant to reasonably develop natural resources and instruct agricultural arrangement.This study firstly discussed the variation and distribution of occupation and supplement croplands in China from 2000 to 2008,then analyzed the climate differentiation between occupation and supplement cropland areas and its effect on light-temperature potential productivity.The results demonstrate:1) From 2000 to 2008,the cropland variation presented occupation in the south and supplement in the north,but overall decreased.Supplement cropland was mainly from ecological reclamation(77.78%) and was mainly distributed in Northeast China and Northwest China with poor climatic and natural conditions.Occupation cropland was mainly used for construction(52.88%) and ecological restoration(44.78%) purposes,and was mainly distributed in the Huang-Huai-Hai Plain,and the middle and lower reaches of the Changjiang(Yangtze) River with better climatic and natural conditions.2) The climate conditions were quite different in supplement and occupation cropland areas.The annual precipitation,annual accumulated temperature and average annual temperature were lower in the supplement cropland area,and its average po-tential productivity per unit was only 62% of occupation cropland area,which was the main reason for the decrease of total potential productivity.3) Cropland occupation and supplement led to the variation of total potential productivity and its spatial distribution.The productivity decreased in the south and increased in the north,but had a net loss of 4.38315×107 t in the whole country.The increase of cropland area was at the cost of reclaiming natural forest and grassland resources,and destroying natural ecological environment,while the decrease of cropland area was mainly due to a lot of cropland occupied by urban-rural construction,which threatened the sustainable use of cropland resources.
文摘Value analysis of grain production influencing factors is a complex decision problem. This paper introduced a modified Analytic Hierarchy Process (AHP) accumulation factor, namely Solving Weight by AHP's Accumulation Factor Sequence Evaluating Data. We used the arithmetical average to replace the expert marking, so that the possible decision mistakes by the subjective judgments could be avoided. We computed the case with this method, which obtained attribute value of 17 influencing factors of the potential food production in Heilongjiang Province, and the result of which was reasonable
文摘Climate warming is expected to influence forest growth,composition and distribution.However,accurately estimating and predicting forest biomass,potential productivity or forest growth is still a challenge for forest managers dealing with land-use at the stand to regional levels.In the present study,we predicted the potential productivity(PP)of forest under current and future climate scenarios(RCP2.6,RCP4.5,RCP6.0 and RCP8.5)in Jilin province,northeastern China by using Paterson’s Climate Vegetation and Productivity(CVP)index model.The PP was validated by comparing it with the mean and maximum net primary production calculated from light energy utilization(GLM_PEM).Our results indicated that using the CVP index model is partially valid for predicting the potential forest productivity in northeastern China.PP exhibited obvious spatial heterogeneity varying from 4.6 to 8.9 m3 ha-1 year-1 with an increasing tendency from northwest to southeast driven by the precipitation across the region.The number of vegetation-active months,precipitation and insolation coefficient were identified as the primary factors affecting PP,but no significant relationship was found for warmest temperature or temperature fluctuation.Under future climate scenarios,PP across the Jilin Province is expected to increase from 1.38%(RCP2.6 in 2050)to 15.30%(RCP8.5 in 2070),especially in the eastern Songnen Plain(SE)for the RCP8.5 scenarios.