• Title/Summary/Keyword: Water supply capacity

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Reassessment on the Four Major Rivers Restoration Project and the Weirs Management (4대강 살리기사업의 재평가와 보의 운용방안)

  • Lee, Jong Ho
    • Journal of Environmental Impact Assessment
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    • v.30 no.4
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    • pp.225-236
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    • 2021
  • The master plan for the Four Rivers Restoration Project (June 2009) was devised, the procedure of pre-environmental review (June 2009) and environmental impact assessment (Nov. 2009), and post-environmental impact survey were implemented, and 4 times audits also inspected. and finally the Ministry of Environment's Four Rivers Investigation and Evaluation Planning Committee proposed the dismantling or partial dismantling of the five weirs of the Geum River and Yeongsan River. But controversies and conflicts are still ongoing. Therefore, this study intend to reestablish the management plan for the four major rivers by reviewing and analyzing the process so far. The results are as follows. First, a cost-benefit analysis should be performed by comparing the water quality impact of weir operation and weir opening. Therefore, it is inevitably difficult to conduct cost-benefit analysis. Second, according to the results of cost-benefit analysis on the dismantling of the Geum River and the Yeongsan River, the dismantling of the weir and the regular sluice gate opening was decided. However, there is a problem in the validity of the decision to dismantle the weir because the cost-benefit analysis for maintaining the weir is not carried out. Third, looking at the change in water quality of 16 weirs before and after the Four Major Rivers Restoration Project, COD and Chl-a were generally deteriorated, and BOD, SS, T-N, and T-P improved. However, in the cost-benefit analysis related to water quality at the time of weir dismantling, only COD items were targeted. Therefore, the cost of BOD, SS, T-N, and T-P items improved after the project were not reflected in the cost-benefit analysis of dismantling weirs, so the water quality benefits were exaggerated. Fourth, in the case of Gongju weir and Juksan weir, most of them are movable weirs, so opening the weir alone can have the same effect as dismantling when the water quality deteriorates. Since the same effect can be expected, there is little need to dismantle the weirs. Fifth, in order to respond to frequent droughts and floods, it is desirable to secure the agricultural water supply capacity to the drought areas upstream of the four majorrivers by constructing a waterway connected to the weir. At present it is necessary to keep weirs rather than dismantling them.

A study on Development Process of Fish Aquaculture in Japan - Case by Seabream Aquaculture - (일본 어류 양식업의 발전과정과 산지교체에 관한 연구 : 참돔양식업을 사례로)

  • 송정헌
    • The Journal of Fisheries Business Administration
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    • v.34 no.2
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    • pp.75-90
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    • 2003
  • When we think of fundamental problems of the aquaculture industry, there are several strict conditions, and consequently the aquaculture industry is forced to change. Fish aquaculture has a structural supply surplus in production, aggravation of fishing grounds, stagnant low price due to recent recession, and drastic change of distribution circumstances. It is requested for us to initiate discussion on such issue as “how fish aquaculture establishes its status in the coastal fishery\ulcorner, will fish aquaculture grow in the future\ulcorner, and if so “how it will be restructured\ulcorner” The above issues can be observed in the mariculture of yellow tail, sea scallop and eel. But there have not been studied concerning seabream even though the production is over 30% of the total production of fish aquaculture in resent and it occupied an important status in the fish aquaculture. The objectives of this study is to forecast the future movement of sea bream aquaculture. The first goal of the study is to contribute to managerial and economic studies on the aquaculture industry. The second goal is to identify the factors influencing the competition between production areas and to identify the mechanisms involved. This study will examine the competitive power in individual producing area, its behavior, and its compulsory factors based on case study. Producing areas will be categorized according to following parameters : distance to market and availability of transportation, natural environment, the time of formation of producing areas (leaderㆍfollower), major production items, scale of business and producing areas, degree of organization in production and sales. As a factor in shaping the production area of sea bream aquaculture, natural conditions especially the water temperature is very important. Sea bream shows more active feeding and faster growth in areas located where the water temperature does not go below 13∼14$^{\circ}C$ during the winter. Also fish aquaculture is constrained by the transporting distance. Aquacultured yellowtail is a mass-produced and a mass-distributed item. It is sold a unit of cage and transported by ship. On the other hand, sea bream is sold in small amount in markets and transported by truck; so, the transportation cost is higher than yellow tail. Aquacultured sea bream has different product characteristics due to transport distance. We need to study live fish and fresh fish markets separately. Live fish was the original product form of aquacultured sea bream. Transportation of live fish has more constraints than the transportation of fresh fish. Death rate and distance are highly correlated. In addition, loading capacity of live fish is less than fresh fish. In the case of a 10 ton truck, live fish can only be loaded up to 1.5 tons. But, fresh fish which can be placed in a box can be loaded up to 5 to 6 tons. Because of this characteristics, live fish requires closer location to consumption area than fresh fish. In the consumption markets, the size of fresh fish is mainly 0.8 to 2kg.Live fish usually goes through auction, and quality is graded. Main purchaser comes from many small-sized restaurants, so a relatively small farmer and distributer can sell it. Aquacultured sea bream has been transacted as a fresh fish in GMS ,since 1993 when the price plummeted. Economies of scale works in case of fresh fish. The characteristics of fresh fish is as follows : As a large scale demander, General Merchandise Stores are the main purchasers of sea bream and the size of the fish is around 1.3kg. It mainly goes through negotiation. Aquacultured sea bream has been established as a representative food in General Merchandise Stores. GMS require stable and mass supply, consistent size, and low price. And Distribution of fresh fish is undertook by the large scale distributers, which can satisfy requirements of GMS. The market share in Tokyo Central Wholesale Market shows Mie Pref. is dominating in live fish. And Ehime Pref. is dominating in fresh fish. Ehime Pref. showed remarkable growth in 1990s. At present, the dealings of live fish is decreasing. However, the dealings of fresh fish is increasing in Tokyo Central Wholesale Market. The price of live fish is decreasing more than one of fresh fish. Even though Ehime Pref. has an ideal natural environment for sea bream aquaculture, its entry into sea bream aquaculture was late, because it was located at a further distance to consumers than the competing producing areas. However, Ehime Pref. became the number one producing areas through the sales of fresh fish in the 1990s. The production volume is almost 3 times the production volume of Mie Pref. which is the number two production area. More conversion from yellow tail aquaculture to sea bream aquaculture is taking place in Ehime Pref., because Kagosima Pref. has a better natural environment for yellow tail aquaculture. Transportation is worse than Mie Pref., but this region as a far-flung producing area makes up by increasing the business scale. Ehime Pref. increases the market share for fresh fish by creating demand from GMS. Ehime Pref. has developed market strategies such as a quick return at a small profit, a stable and mass supply and standardization in size. Ehime Pref. increases the market power by the capital of a large scale commission agent. Secondly Mie Pref. is close to markets and composed of small scale farmers. Mie Pref. switched to sea bream aquaculture early, because of the price decrease in aquacultured yellou tail and natural environmental problems. Mie Pref. had not changed until 1993 when the price of the sea bream plummeted. Because it had better natural environment and transportation. Mie Pref. has a suitable water temperature range required for sea bream aquaculture. However, the price of live sea bream continued to decline due to excessive production and economic recession. As a consequence, small scale farmers are faced with a market price below the average production cost in 1993. In such kind of situation, the small-sized and inefficient manager in Mie Pref. was obliged to withdraw from sea bream aquaculture. Kumamoto Pref. is located further from market sites and has an unsuitable nature environmental condition required for sea bream aquaculture. Although Kumamoto Pref. is trying to convert to the puffer fish aquaculture which requires different rearing techniques, aquaculture technique for puffer fish is not established yet.

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Arsenic Removal Using Iron-impregnated Ganular Activated Carbon (Fe-GAC) of Groundwater (철침착 입상활성탄(Fe-GAC)을 이용한 지하수 내 비소 제거기술)

  • Yoon, Ji-Young;Ko, Kyung-Seok;Yu, Yong-Jae;Chon, Chul-Min;Kim, Gyoo-Bum
    • Economic and Environmental Geology
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    • v.43 no.6
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    • pp.589-601
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    • 2010
  • Recently it has been frequently reported arsenic contamination of geologic origin in groundwater. The iron-impregnated ranular activated carbon (Fe-GAC) was developed for effective removal of arsenic from groundwater n the study. Fe-GACs were prepared by impregnating iron compounds into a supporting medium (GAC) with 0.05 M iron nitrate solution. The materials were used in arsenic adsorption isotherm tests to know the effect of iron impregnation time, batch kinetic tests to understand the influence of pH, and column tests to evaluate for the preliminary operation of water treatment system. The results showed that the minimum twelve hours of impregnation time were required for making the Fe-GAC with sufficient iron content for arsenic removal, confirmed by a high arsenic adsorption capacity evaluated in the isotherm tests. Most of the impregnated iron compounds were iron hydroxynitrate $Fe_4(OH)_{11}NO_3{\cdot}2H_2O$ but a mall quantity of hematite was also identified in X-ray diffraction(XRD) analysis. The batch isotherms of Fe-GAC for arsenic adsorption were well explained by Langmuir than Freundlich model and the iron contents of Fe-GAC have positive linear correlations on logarithmic plots with Freundlich distribution coefficients ($K_F$ and Langmuir maximum adsorption capacities ($Q_m$. The results of kinetic experiments suggested hat Fe-GAC had he excellent arsenic adsorption capacities regardless of all pH conditions except for pH 11 and could be used a promising adsorbents for groundwater arsenic removal considering the general groundwater pH range of 6-8. The pseudo-second order model, based on the assumption that the ate-limiting step might be chemisorption, provided the best correlation of the kinetic experimental data and explained the arsenic adsorption system f Fe-GAC. The column test was conducted to valuate the feasibility of Fe-GAC use and the operation parameters in arsenic groundwater treatment system. The parameters obtained from the column test were the retardation actor of 482.4 and the distribution coefficient of 581.1 L/mg which were similar values of 511.5-592.5 L/mg acquired from Freundlich batch isotherm model. The results of this study suggested that Fe-GAC could be used as promising adsorbent of arsenic removal in a small groundwater supply system with water treatment facility.

Characteristics of Water Environment on Manun Reservoir (중산간 농업용 만운저수지의 수질환경특성)

  • Nam, Gui-Sook;Jang, Jeong-Ryeol;Lee, Gwang-Sik;Yoon, Keung-Sup;Lee, Sang-Joon
    • Korean Journal of Environmental Agriculture
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    • v.22 no.1
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    • pp.16-25
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    • 2003
  • Manun Reservoir, located in Andong district has the capacity of 2 million tons in irrigation water supply with the drainage area of $23.8\;km^2$. Manun Reservoir is over fifty year old, and shallow in depth. The ratio of drainage area (DA) to reservoir surface area (SA) as an effective physical parameter on water quality was 56.1 and was higher than those of other agricultural reservoirs. The ratio of reservoir storage (ST) to SA in Manun Reservoir was 4.79, and the mean depth was below 8m. Both ratios of DS/SA, total area (TA)/ST and ST/SA in Manun Reservoir were relatively higher than those in other agricultural reservoir and natural lakes in Korea. These physical parameters in Manun Reservoir, however, had a eutropic potential significance. Average of COD, IN, and TP in Manun Reservoir were 11.1 mg/L 1.426 mg/L, 0.093 mg/L, respectively. In the inflow stream of Manun Reservoir, the TN ($1.426{\sim}3.809\;mg/L$) was higher than those in reservoir. Only Lyngbya spp. was dominant in phytoplankton for this study period and Gymnodinium spp., Peridinium spp., and Cryptomonas spp. were dominant in zooplankton. According to the Carlson's trophic status index, Mnnun Reservoir was eutrophic in 1996, 1997, and 1999, and hypertrophic in 1998.

Experiment on Chloride Adsorption by Calcium Aluminate Phases in Cement (시멘트내 칼슘 알루미네이트 상에 의한 염소이온의 흡착반응 연구)

  • Yoon, In-Seok
    • Journal of the Korea Concrete Institute
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    • v.29 no.4
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    • pp.389-397
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    • 2017
  • Friedel's salt is an important product of chemical adsorption between cement hydrate and chloride ions because it contains chlorine in its structure. When cement reacts with water in the presence of chloride ions, the $C_3A$ phase, and $C_4AF$ phase react with chloride to produce Friedel's salt. If chloride ions penetrate into concrete from external environments, many calcium aluminate hydrates, including AFm, can bind chloride ions. It is very important, therefore, to investigate the chloride binding isotherm of $C_3A$ phase, $C_4AF$ phase, and AFm phase to gain a better understanding of chloride binding in cementitious materials. Meanwhile, the adsorption isotherm can provide us with the fundamental information for the understanding of adsorption process. The experimental results of the isotherm can supply not only the quantitative knowledge of the cement-Friedel's salt system, but also the mechanism of adsorption and the properties of their interactions. The purpose of this study is to explore the time dependant behaviors of chloride ions adsorption with $C_3A$, $C_4AF$ and AFm phases. The chloride adsorption isotherm was depicted with Langmuir isotherm and the adsorption capacity was low in terms of the stoichiometric point of view. However, the chloride adsorption of AFm phase was depicted with Freundlich isotherm and the value was very low. Since the amount of the adsorption was governed by temperature, the affecting parameters of isotherm were expressed as a function of temperature.

Process Simulation and Economic Feasibility of Upgraded Biooil Production Plant from Sawdust (톱밥으로부터 생산되는 개질 바이오오일 생산공장의 공정모사 및 경제성 분석)

  • Oh, Chang-Ho;Lim, Young-Il
    • Korean Chemical Engineering Research
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    • v.56 no.4
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    • pp.496-523
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    • 2018
  • The objective of this study is to evaluate the economic feasibility of two fast pyrolysis and biooil upgrading (FPBU) plants including feed drying, fast pyrolysis by fluidized-bed, biooil recovery, hydro-processing for biooil upgrading, electricity generation, and wastewater treatment. The two FPBU plants are Case 1 of an FPBU plant with steam methane reforming (SMR) for $H_2$ generation (FPBU-HG, 20% yield), and Case 2 of an FPBU with external $H_2$ supply (FPBUEH, 25% yield). The process flow diagrams (PFDs) for the two plants were constructed, and the mass and energy balances were calculated, using a commercial process simulator (ASPEN Plus). A four-level economic potential approach (4-level EP) was used for techno-economic analysis (TEA) under the assumption of sawdust 100 t//d containing 40% water, 30% equity, capital expenditure equal to the equity, $H_2$ price of $1050/ton, and hydrocarbon yield from dried sawdust equal to 20 and 25 % for Case 1 and 2, respectively. TCI (total capital investment), TPC (total production cost), ASR (annual sales revenue), and MFSP (minimum fuel selling price) of Case 1 were $22.2 million, $3.98 million/yr, $4.64 million/yr, and $1.56/l, respectively. Those of Case 2 were $16.1 million, $5.20 million/yr, $5.55 million/yr, and $1.18/l, respectively. Both ROI (return on investment) and PBP (payback period) of Case 1(FPBU-HG) and Case 2(FPBU-EH) were the almost same. If the plant capacity increases into 1,500 t/d for Case 1 and Case 2, ROI would be improved into 15%/yr.

Effect of EC Level of Nutrient Solution on the Yield and Quality of Cut Rose Based on Mixed Coir and Perlite (코이어와 펄라이트 혼합배지를 이용한 절화장미 수경재배 시급액농도가 수량 및 품질에 미치는 영향)

  • Choi, Gyeong-Lee;Cho, Myeong-Whan;Seo, Tae-Cheol;Roh, Mi-Young;Rhee, Han-Cheol
    • Journal of Bio-Environment Control
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    • v.18 no.4
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    • pp.348-353
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    • 2009
  • Organic materials reveal the remarkable absorption and high buffer capacity for nutrient. Hence, organic materials need some different nutrient management skill from inorganic one. The objective of this study was to evaluate the effect of EC level of nutrient solution on the yield and quality of cut rose grown in the mixed substrate of coir and perlite. 3 EC levels of nutrient solution was treated, which were 0.7, 1.0, 1.3 times of standard solution (Aichiken solution, Japan) for cut rose hydroponics. EC of the standard solution was changed by season following as 1.4 (Apr.~June), 1.0 (July~Aug.), 1.4 (Sep.~Oct.), and $1.6dS{\cdot}m^{-1}$ (Nov.~Mar.) subsequently. The supply of nutrient solution was controlled by the signal of water potential at -5kPa using frequency domain reflectometry (FDR) sensor. As the results, marketable yield was similar for all treatments until 3rd harvest, but was decreased in high EC level from 4th harvest to 7th harvest as final. 0.7 times of standard solution decreased the ratio of unmarketable rose having short stem below 70cm and increased the ratio of high quality rose having long stem above 91cm. The flower weight and stem diameter of cut rose was higher in the low EC treatment than the others.

An Expanded Use of Reactor Power Cutback System to Avoid Reactor Trips in the Event of an Inward Control Element Assembly Deviation (제어봉 인입편차시의 원자로 비상정지 방지를 위한 출력 급감발 계통의 확대 적용)

  • Hwang, Hae-Ryong;Ahn, Dawk-Hwan
    • Nuclear Engineering and Technology
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    • v.25 no.2
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    • pp.276-284
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    • 1993
  • The ABB-CE System-80 reactor power cutback system(RPCS) is designed to enable continuous operation of the reactor without trip in the events of the loss of one of the two main feedwater pumps and loss of load, and thus improves plant availability in a cost effective manner. In this study expansion of RPCS has been investigated for continuous reactor operation without trip in the event of an inward control element assembly(CEA) deviation including a single rod drop. Under the expanded function of RPCS the control system will provide a rapid core power reduction on demand by releasing CEAs to drop into the core and reduce the turbine power, if necessary, to follow the reactor power variation. This design feature which is included as the new design features to be incorporated in the ABB-CE System-80+ meets the EPRI advanced light water reactor(ALWR) requirements. For this study core analysis models of System-80+ have been developed to simulate the nuclear steam supply system(NSSS) response as well as the RPCS initiation of rapid CEA insertion. The results of this study demonstrate that the reactor trip can be avoided in the event of inward CEA deviation including a single rod drop by the RPCS initiation and thus the plant availability and capacity factor would be increased.

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Growth Performance and Carcass Evaluation of Jeju Native Cattle and Its Crossbreds Fed for Long Fattening Period

  • Lee, W.S.;Oh, W.Y.;Lee, S.S.;Khan, M.A.;Ko, M.S.;Kim, H.S.;Ha, J.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.12
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    • pp.1909-1916
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    • 2007
  • This study compared the growth performance and carcass evaluation of Jeju native cattle (JNC) and its crossbreds (CBK = 25 JNC:50 Charolais:25 Brahman and BCBK = 62.5 JNC:25 Charolais:12.5 Brahman). Eight male calves of each JNC, CBK and BCBK were weaned at 4 month of age and were fed for 24 months of age. All animals grazed a pasture between 5 to 10 months of age then they were fed growing ration at the rate of 1.5% of their BW along with ad libitum supply of Italian ryegrass hay between 11 to 16 months of age and thereafter switched to ad libitum feeding of finishing ration and hay between 17 to 24 months of age. Mean body weight (BW) and BW gain were higher in CBK compared with BCBK and JNC at 4, 10, 16 and 24 months of age. Average daily BW gain during 4 to 10 months of age was the highest for CBK followed by BCBK and JNC. However, daily BW gain was higher in BCBK than in CBK and JNC during 11 and 16 months of age. During fattening period (17 to 24 months) average daily BW gain was higher in JNC than in CBK and BCBK. Slaughter weight, hot and cold carcass weight were higher in CBK compared with JNC and BCBK. Weight of bones, boneless meat, ribs, excluded rib meat, retailed cut meat, tender loin, sir loin, strip loin, sticking, top round, bottom round, fore leg, shank, and thin-flank were higher in CBK than in BCBK and JNC. Fat weight in these carcass cuts and kidney fat was similar in JNC and its crossbreds. Logissimus dorsi and its ratio were higher in CBK compared with BCBK and JNC. Percent moisture, crude protein, and ash contents of beef were similar in JNC and its crossbreds. Percent beef fat was higher in JNC and BCBK than in CBK. Cooking loss and water holding capacity of beef was similar in JNC and its crossbreds. Sheer force was lower in BCBK compared with JNC and CBK. Juiciness, tenderness and flavor of beef were higher in BCBK compared with JNC and CBK. In conclusion, CBK has shown higher growth rate and produced heavier carcasses with good degree of fatness compared with JNC and BCBK. However, fattening for longer period could increase the maintenance cost in CBK and BCBK because of their higher BW which they attained during growing period.

Soil Characteristics and its Influences on the Yields and Quality of Red Pepper in Yeongyang Area, Gyeongbug Province (경북 영양지역 고추 재배지 토양의 특성)

  • Choi, Jyung;Son, Il-Soo;Jung, Yeun-Tae;Lee, Dong-Hoon;Park, Man;Choi, Choong-Lyeal
    • Korean Journal of Soil Science and Fertilizer
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    • v.33 no.3
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    • pp.145-152
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    • 2000
  • The total acreage of 4,894ha of upland soils in Yeongyang area, the main crop cultivated were red-pepper. They were distributed mainly on local valleys and alluvial fans(54.9%), about 61.2% had 7~15% slopes, and about 73.2% had fine loamy family in soil texture. the soils were classified into Ochrepts(73.7%). Udalfs(16.9%), Fluvents(6.2%) and Psamments(3.2%) etc. The upland soils with 100~250m in altitude and "moderately well drained" had higher contents in inorganic nutrients. The red-pepper Produced in the high altitude(>400m) were lower in quality and yields, while the content of sugar and yields of pepper produced in fine loamy textured soils were higher than other soil textures. The yields of red-pepper produced in the "moderately well drained" soils which had better water supply capacity were higher than "well drained" soils.

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