Agricultural Water Supply Research Articles

The Systematization Project of the Technology to Make Agriculture Water Supply Facilities Durable and the Analysis of Deterioration of Concrete Canals

The Systematization Project of the Technology to Make Agriculture Water Supply Facilities Durable and the Analysis of Deterioration of Concrete Canals

농업용 관수로의 최적관경 선정을 위한 개선방안 연구

전통적으로 농업용수 공급시설은 개수로의 형태가 대부분이었으나 비효율적이고 운영 및 관리에 어려움이 있다는 단점이 지적되어 왔다. 최근 들어 이러한 단점을 보완하기 위해, 안정적인 용수공급과 시스템 관리가 용이한 관수로 시스템으로의 전환이 모색되고 있다. 경제성을 고려한 농업용 관수로 시스템의 설계를 위해서는 최적화 기법의 적용이 반드시 필요하다. 하지만, 기존의 최적화 기법들은 결정변수가 많은 대규모 시스템에 적용할 경우 계산효율이 떨어지고, 실무에 사용이 가능한 해를 제시하지 못하는 경우가 많았다. 본 연구에서는 기존의 최적화 기법이 가지는 이러한 문제점을 개선할 수 있는 방안을 개발하고 적용하였다. 적용 모형은 관망 수리해석 프로그램인 EPANET모형과 군탐색 최적화 기법인 유전자 알고리즘(Genetic Algorithm)을 연계하도록 구성되었다. 기존의 유전자 알고리즘이 초기해(Initial Population)로 무작위해(Random Solution)를 사용하는 것과 달리, 본 연구에서는 수리해석을 이용한 전처리과정을 통해 선정된 초기전략해(Strategic Initial Population)를 사용함으로써 최적화 알고리즘의 계산효율을 높이고 동시에 전역해(Global Optimum)에 근접한 최적설계가 가능하도록 하였다. 개발된 모형을 대규모 농업단지에 적용한 결과 기존의 최적화 기법에 비해 경제적, 수리학적으로 개선된 설계결과를 얻을 수 있었다. 본 논문에서는 초기전략해를 이용한 농업용 관수로 시스템의 최적화기법을 상세히 설명하고, 그 적용절차 및 결과를 제시하였다. Traditionally, open channel flow systems have been mainly utilized for agricultural irrigation water supply. To date, a pipe network system is gaining spotlight as an alternative in this field for reliable and efficient water supply. Optimization techniques are beneficial for least-cost design of large-scale irrigation systems. Previous optimization techniques, however, had drawback in terms of computational efficiency when applied to a large scale system with lots of decision variables, and often provided solutions not applicable to real network design. In this study, an improved approach for determining optimal diameter of agricultural pipe systems are proposed. The model consists of a heuristic search approach, Genetic Algorithm (GA), and a hydraulic simulator, EPANET. Instead of using random initial population for GA, a strategic initial population was constructed and provided from a pre-processing based on iterative hydraulic analyses. The proposed approach enabled the optimal design to be found and improved computational efficiency of GA. The developed model was applied to a large-scale irrigation network and optimal designs were obtained with lower economic cost yet better hydraulic performances. This paper describes the proposed approach utilizing the strategic initial population and the application procedures and results are discussed.

Disconnected runoff contributing areas: Evidence provided by ancient watershed management systems in arid north-eastern Marmarica (NW-Egypt)

This study presents the importance of disconnectivity in dryland area runoff demonstrated by manmade water harvesting structures dated to Greco-Roman times. Located on the coastal strip of some 20km width along the Mediterranean coast of modern northwestern Egypt covering the north-eastern part of the region known in antiquity as Marmarica, the area receives winterly rainfalls of up to 140mm. Further south, precipitation decreases quickly and desert conditions become more pronounced. Bedrocks are predominantly calcareous, soils are loamy, stony, calcareous, and shallow, except in relief sinks with sedimentary deposits. The land rises from the coast up to 230ma.s.l. on the Marmarica Plateau in a sequence of zonal northsloping plains and scarps the northern parts of which are dissected and drained by wadis. Agriculturally suitable areas comprise some 9% of the coastal zone and adjacent tablelands. Overland flow controls the discharge dynamics and is the main source of wadi runoff and hence agricultural water supply. The land use pattern is scattered because cropping areas depend mainly on suitability of soils and the generation of runoff harvest, which are closely interrelated because of the arid water and sediment regime. The patchiness of runoff generation increases further south where aridity is higher and topography inhibits greater drainage patterns. The abundance of cisterns, many of them originally Greco-Roman, is strong evidence that tableland overland flows occur and are frequently disconnected from larger drainage systems.Abandoned ancient rainwater harvesting and watershed management systems are abundant all over the region and incorporate the hydrological experience of the former inhabitants, having been dated with OSL and pottery mainly from Greco-Roman times. While the region prospered some two millenia ago, the ancient water management schemes are generally abandoned today.One of the most outstanding features of the ancient systems was the systematic harvesting of tableland and valley slope overland flow above the wadi beds. Part of this strategy was to separate the remote parts of large natural watersheds from the local parts by shallow stone bunds on the tableland. The collected tableland overland flow irrigated terraced fields on the tableland (kurum). The remaining water harvesting areas, mainly valley slopes, were obviously sufficient to supply water for small tributary wadis, large side terraces and the floodplains of large wadis. The artificial disconnection of local runoff areas from remote parts of the northern watersheds is hydrologically well adapted to the runoff dynamics in the flat landscape of the northern Marmarica because it protected valleys from low frequency high magnitude runoff events which are generated mainly on the remote parts of large catchments but which are inefficient in terms of water harvesting. Terracing and water harvesting structures are frequently buried in well-sorted, fine-grained sediment.

Assessing and classifying plant-related ecological risk under water management scenarios in China's Yellow River Delta Wetlands

The Yellow River Delta is one of the most vigorous delta areas in the world. The wetlands in this delta are ecologically important due to their hydrologic attributes and their role as ecotones between terrestrial and aquatic ecosystems. In recent years, the Yellow River Delta Wetlands have gradually shrunk and degraded due to inadequate environmental flows. Water managers have attempted to balance the needs of the environment with the need to protect water supplies for agriculture and urban needs. Despite the need for environmental protection, a broad-scale, integrated way to characterize the degree of ecological stress in the wetlands has been lacking to date. To provide a framework for evaluating various potential water regimes, we developed a model that can be used to estimate the ecological risk for wetland plants, and used the model to determine the degree of ecological risk for different soil moisture conditions based on an ecological value at risk model that we developed and the fuzzy clustering method. The results revealed the spatial distribution of areas with high, medium, or low risks associated with water stress in the study area. These results can serve as a preliminary template to guide managers in their evaluation of water stress-related risk.

Residual effect of Polychlorinated biphenyls (PCBs) in sediment from CauBay River, Vietnam

Background An evaluation of residual effect of Polychlorinated biphenyls (PCBs) in sediment from CauBay River, Vietnam was carried out. This river has been playing an important role in water supply and drainage for agriculture at Kieu Ky commune, Hanoi, the capital of Vietnam. Aims The aims of the this research are to assess the PCBs residue in sediment and its effect to the quality of soil of Kieu Ky commune at the downstream of CauBay river. Methods Twenty representative sediment and soil samples were collected in October 2012. The concentrations of PCBs in the sediment samples were investigated by GC/MS. Results In industrial and urban sampling sites, PCBs concentrations in sediment samples ranged from 10.02 to 169.52 ng g-1 dry weight, while those in agricultural sampling sites ranged from 8.02 to 24.37 ng g-1 dry weight. All sediment samples in CauBay river are lower than ERM level (180 ng g-1) and ninety percent of samples are higher than ERL level (22.7 ng g-1). Compositions analyses show that the predominance of heavily chlorinated PCBs, PCB138 and PCB153, are still remained when they penetrated the sediment from CauBay river and soil from Kieu Ky commune. In soil sample from Kieu Ky commune, PCBs was detected from 9.08 to 110.62 ng g-1 dry weight. There is a strong positive relation between residue of PCBs from sediment of CauBay river and from soil of Kieu Ky commune (Pearson’ correlation coefficient is 0.87). Conclusions Wide occurrence and high residue of PCBs has been found in the study area. There is a strong positive relation between residue of PCBs from sediment of CauBay river and from soil of Kieu Ky commune. Compositions analyses show that the predominance of heavily chlorinated PCBs are still remained when they penetrated CauBay river. The long-time release of PCBs levels is observed.

Trade-Offs in Water Policy: System-Wide Implications of Changing Water Availability and Agricultural Productivity in the Mediterranean Economies by 2050

We evaluate the structural consequences of water availability scenarios in the Mediterranean, following a multidisciplinary approach and a sequential modelling methodology. This includes an assessment of future water availability and a general equilibrium macroeconomic analysis of changes in agricultural productivity. Lower productivity in agriculture, induced by reduced water availability, generates negative consequences in terms of real income and welfare. The magnitude of the loss depends on the amount of the productivity shock, but also on the share of agricultural activities in the economy and on the stringency of the environmental regulation. We find evidence of a dramatic cut in the supply of water for agriculture in the Middle East. We consider alternative scenarios, differing in terms of stringency of environmental regulation and assumptions about water efficiency. The largest welfare losses turn out to be in Morocco and Tunisia, in the “worst” scenario NM. Other very relevant impacts can be observed in Turkey, Italy and Rest of Middle East and North Africa (XMENA). There are also clear differences among the scenarios. First, applying a constraint on access to environmental water reserves only for Europe does make a big difference for non-European countries (Morocco, Tunisia and XMENA), implying that governments in the Middle-East could respond to increasing water scarcity by accepting, to some extent, lower environmental quality (deterioration of aquatic environments). Second, improvements in water efficiency, as envisaged in the simulation exercise, appear to curb the economic impact of water scarcity quite significantly. This is especially true for countries in the North, whereas efficiency does not compensate for a strict environmental policy in the South.

Econometric Forecasting of Irrigation Water Demand Conserves a Valuable Natural Resource

Natural causes (such as droughts), non-natural causes (such as competing uses), and government policies limit the supply of water for agriculture in general and irrigating crops in particular. Under such reduced water supply scenarios, existing physical models reduce irrigation proportionally among crops in the farmer's portfolio, disregarding temporal changes in economic and/or institutional conditions. Hence, changes in crop mix resulting from expectations about risks and returns are ignored. A method is developed that considers those changes and accounts for economic substitution and expansion effects. Forecasting studies based on this method with surface water in Georgia and Alabama demonstrate the relative strength of econometric modeling vis-à-vis physical methods. Results from a study using this method for ground water in Mississippi verify the robustness of those findings. Results from policy-induced simulation scenarios indicate water savings of 12% to 27% using the innovative method developed. Although better irrigation water demand forecasting in crop production was the key objective of this pilot project, conservation of a valuable natural resource (water) has turned out to be a key consequence.

Climate change impacts on maritime mountain snowpack in the Oregon Cascades

Abstract. This study investigates the effect of projected temperature increases on maritime mountain snowpack in the McKenzie River Basin (MRB; 3041 km2) in the Cascades Mountains of Oregon, USA. We simulated the spatial distribution of snow water equivalent (SWE) in the MRB for the period of 1989–2009 with SnowModel, a spatially-distributed, process-based model (Liston and Elder, 2006b). Simulations were evaluated using point-based measurements of SWE, precipitation, and temperature that showed Nash-Sutcliffe Efficiency coefficients of 0.83, 0.97, and 0.80, respectively. Spatial accuracy was shown to be 82% using snow cover extent from the Landsat Thematic Mapper. The validated model then evaluated the inter- and intra-year sensitivity of basin wide snowpack to projected temperature increases (2 °C) and variability in precipitation (±10%). Results show that a 2 °C increase in temperature would shift the average date of peak snowpack 12 days earlier and decrease basin-wide volumetric snow water storage by 56%. Snowpack between the elevations of 1000 and 2000 m is the most sensitive to increases in temperature. Upper elevations were also affected, but to a lesser degree. Temperature increases are the primary driver of diminished snowpack accumulation, however variability in precipitation produce discernible changes in the timing and volumetric storage of snowpack. The results of this study are regionally relevant as melt water from the MRB's snowpack provides critical water supply for agriculture, ecosystems, and municipalities throughout the region especially in summer when water demand is high. While this research focused on one watershed, it serves as a case study examining the effects of climate change on maritime snow, which comprises 10% of the Earth's seasonal snow cover.

Determining appropriate instream flows for anadromous fish passage on an intermittent mainstem river, coastal southern California, USA

ABSTRACTSetting instream flows to protect aquatic resources is required by California state law, but this task is not straightforward for an intermittent river that is naturally dry six or more months of every year. The Santa Maria River, 200 km northwest of the Los Angeles metropolitan area, lies within the northern range of the federally endangered southern California steelhead (Oncorhynchus mykiss) and is a logical candidate for instream flow protection: the watershed historically supported the anadromous life history of this species, but fish must navigate the lowermost 39 km of the commonly dry mainstem river to move between the ocean and freshwater habitats in the upper watershed. Mainstem flows are partly controlled by Twitchell Dam, constructed across one of the Santa Maria River's two main tributaries in 1962. The dam is operated to maximize groundwater recharge through the bed of the mainstem Santa Maria River, thus minimizing discharge to the Pacific Ocean and so reducing already limited steelhead passage opportunities. Conventional criteria for determining suitable instream flows for steelhead passage are ill‐suited to intermittent, Mediterranean‐type rivers because they ignore the dynamic channel morphology and critical importance of headwater flows in providing cues that once presaged passage‐adequate mainstem discharges but no longer do so. Hydrologic analysis of pre‐dam flows, coupled with established criteria for successful O. mykiss migration, provides an objective basis for evaluating alternative dam‐management scenarios for enhancing steelhead passage, although their implementation would redirect some water that for the past half‐century has exclusively supported irrigated agriculture and municipal water supplies. Copyright © 2013 John Wiley & Sons, Ltd.

Measures against climate change and its impacts on water resources in Greece

This paper examines the actions toward the reduction of greenhouse gas emissions to the atmosphere that Greece has implemented to comply with international conventions and the Kyoto Protocol. It also concerns the analysis and processing of climate variables and the assessment of the impact of climate change on water resources in Northern Greece and on some critical water management issues, such as reservoir storage and water supply for agriculture and domestic use. Initially, a monthly conceptual water balance model was applied to estimate runoff values in the entrance of the Polyfyto reservoir under the UKHI equilibrium scenario referring to the year 2100. It was found that the mean annual runoff, mean winter runoff and summer runoff values will be reduced. Increases of the risks associated with the annual quantities of water supply have been observed.

기후변화를 고려한 제주지역의 권역별 가뭄 평가 및 농업용수에의 영향 고찰

Recently, the occurrences of droughts have been increased because of global warming and climate change. Water resources that mostly rely on groundwater are particularly vulnerable to the impact of precipitation variation, one of the major elements of climate change, are very sensitive to changes in the seasonal distribution as well as the average annual change in the viewpoint of agricultural activity. In this study, the status of drought for the present and future on Jeju Island which entirely rely on groundwater using SPI and PDSI were analyzed considering regional distribution of crops in terms of land use and fluctuation of water demand. The results showed that the precipitation distribution in Jeju Island is changed in intensity as well as seasonal variation of extreme events and the amount increase of precipitation during the dry season in the spring and fall indicated that agricultural water demand and supply policies would be considered by regional characteristics, especially the western region with largest market garden crops. Regarding the simulated future drought, the drought would be mitigated in the SPI method because of considering total rainfall only excluding intensity variation, while more intensified in the PDSI because it considers the evapotranspiration as well as rainfall as time passed. Moreover, the drought in the northern and western regions is getting worse than in the southern region so that the establishment of regional customized policies for water supply in Jeju Island is needed.

제주도 권역별 농업용수 수요량 산정에 대한 고찰

Over 96.2% of the agricultural water in Jeju Island is obtained from groundwater and there are quite distinct characteristics of agricultural water demand/supply spatially because of regional and seasonal differences in cropping system and rainfall amount. Land use for cultivating crops is expected to decrease 7.4% (4,215 ha) in 2020 compared to 2010, while market garden including various vegetable crop types having high water demand is increasing over the Island, especially western area having lower rainfall amount compared to southern area. On the other hand, land use for fruit including citrus and mandarin having low water demand is widely distributed over southern and northern part having higher rainfall amount. The agricultural water demand of in 2020 is estimated about 1.39 times compared to groundwater supply capacity of in 2010 with 42.4% of eastern, 103.1% of western, 61.9% of southern, and 77.0% of northern region. Moreover, net secured amount of agricultural groundwater would be expected to be much smaller due to regional disparity of water demand/supply, the lack of linkage system between the agricultural water supply facilities, and high percentage of private wells. Therefore, it is necessary to ensure the total net secured amount of agricultural groundwater to overcome the expected regional discrepancy of water demand and supply by establishing policy alternative of regional water supply plan over the Island, including linkage system between wells, water tank enlargement, private wells maintenance and public wells development, and continuous enlargement of rainwater utilization facilities.

Water resources and groundwater quality in North Peloponnesus (Greece)

Groundwater plays an important role for urban and agricultural water supply in northern part of Peloponnesus. Despite increasing environmental awareness in this area, groundwater is a resource that is being stressed. Groundwater provides about 80% the total quantity of water supply. Distribution of water resources is nonhomogeneous in this region. In general the eastern part is semiarid, whereas the western part is supplied with abundant water. Surface water potential in North Peloponnesus estimated to be 0.9- 1.2x109 m3 y-1. Overexploitation of groundwater and the extensive agriculture has created environmental problems in some aquifers (sea water intrusion, nitrate pollution). Seawater intrusion occurs in some coastal aquifers, where negative water balance has been established. High percentage of the examined samples exceeded the maximum admissible nitrate concentration of 50 mg l-1, set by EU for drinking water. Groundwater in urban areas has been contaminated to varying degrees. The water quality is classified into Ca-HCO3 type (fresh water) and Na-HCO3 or Na-Cl type (brackish waters) in the coastal part, due to seawater intrusion. Some recommendations are made in order to safeguard high water quality and to develop new ways of providing water source in the study area. Moreover, an integrated and comprehensive management scheme should be applied, aiming at sustainability of water resources and based on surface water and groundwater exploitation, simultaneously.

Groundwater hydrochemical characteristics and processes along flow paths in the North China Plain

The North China Plain is one of the biggest plains in China, where municipal, agricultural and industrial water supplies are highly dependent on groundwater resources. It is crucial to investigate water chemistry and hydrogeochemical processes related to hydrogeologic settings for sustainable utilization of groundwater resources. Two hydrochemical profiles proximately along the groundwater flow paths were selected for hydrogeochemical study. Major components and 2H and 18O isotopes were analyzed in groundwater samples from the profiles. The study area was divided into three zones, including strong runoff-alluvial/pluvial fans in the piedmont area (Zone I), slow runoff-alluvial/lacustrine plain in the central area (Zone II), and discharge-alluvial/marine plain in the coastal area (Zone III). Major components of groundwater samples showed obvious zonation patterns from Zone I to Zone III. Total dissolved solid (TDS) concentrations gradually increased, and the hydrochemical type changed from HCO3–SO4–Ca–Mg and HCO3–Cl–Ca–Mg types to HCO3–SO4–Na–Ca, SO4–Cl–Na–Ca and SO4–Cl–Na types from Zone I to Zone III. Abrupt increases in concentrations of Na+, Cl− and SO42- in deep groundwater were observed around the depression cones, which indicated that overexploitation resulted in water quality deterioration. Calcite and dolomite precipitation occurred in Zone I of deep groundwater systems and shallow groundwater systems. Cation exchange was believed to take place along the entire flow paths. Gypsum tended to dissolve in groundwater systems. The depletion in D and 18O isotopes in deep groundwater was related to the recharge from precipitation in paleo-climate conditions in glacial or interglacial periods, indicating that renewal groundwater was very limited. Efficient strategies must be taken to preserve the valued water resources for sustainable development.

Natural Resources as a Factor Socioeconomic Development: The Case Northeastern Montenegro

The paper discusses the natural resources of the northeastern of Montenegro as a factor of socio-economic development. Based on the properties of relief, we have selected three relatively homogeneous regions for economic development. Area sub region alluvial plains of rivers, river terraces, lake sediments Berane, Andrijevica and Polimlja Valley has the most favorable conditions for intensive agricultural production, summer tourism, construction and transport development. Diversity and complementarily of water resources is the main characteristic of the considered region, which is of particular importance for the future economic development. In the water resources, we looked at the possibilities of exploiting hydropower, water supply of population and industry, agriculture water supply. Thanks to the geological structure of the valley Berane there are significant reserves of brown coal and lignite (total reserves are 176.231.197 tons). Program development and production of coal in the valley Berane would cause intense regrouping and integration of industrial enterprises and caused the need for capacity expansion (Beran Village, Dolac). In the region, appear to ore metals: lead, zinc, copper, iron and pyrite. From non-metallic mineral resources, occupy their presence and reservoir construction materials: gravel, sand and decorative stone. Agricultural land is an important part of the natural wealth of the region. In the period 1964-2005 in the agricultural land there was a change in the way of exploitation to reduce the area under fields and gardens and pastures and increased the area under orchards and meadows.

粉垄耕作对黄淮海北部土壤水分及其利用效率的影响

Annual rotary tillage often can create a compacted plough pan in shallow soil layers,and result in the decrease of soil fertility and crop yield due to the reduction of water storage and nutrient supply. Meanwhile,the decreased water use efficiency has worsened the imbalance between supply and demand of agricultural water,especially in water shortage regions. In order to minimize such negative effects caused by annual rotary tillage,a new deep soil tillage method called deep vertically rotary tillage with use of vertically corkscrew aiguilles was implemented to test its role in improving soil water movement and water use efficiency in northern China' s Huang-huai-hai region. Eight treatments including deep vertically rotary tillage to 30 cm( treatmentⅠ),deep vertically rotary tillage to 50 cm( treatmentⅡ),deep vertically rotary tillage to 30 cm with plastic film mulching( treatment Ⅲ),deep vertically rotary tillage to 50 cm with plastic film mulching( treatment Ⅳ),deep vertically rotary tillage to 30 cm with no-cultivation( treatment Ⅴ) and deep vertically rotary tillage to 50 cm with no-cultivation( treatment Ⅵ) were conducted,while rotary tillage( treatment Ⅶ) and subsoiling( treatment Ⅷ) were used as experimental control. Based on the analysis of soil moisture contour mapping,soil water consumption and water use efficiency among different treatments,several main results were found.( 1) Compared with rotary tillage and subsoiling,cultivated soil layers by deep vertically rotary tillage became looser and deeper. Therefore,rain-water infiltration and soil water up-and-down transferring capacity under deep vertically rotary tillage were improved,which resulted in the reduction of total crop water consumption and promotion of water use efficiency. For instance,the total crop water consumption of treatmentⅠ—Ⅳ decreased by 12.2%—16.4% and 10.2%—14.5% with respect to that of rotary tillage and subsoiling,respectively. Furthermore,the water use efficiency at yield level of treatment Ⅰ—Ⅳ increased by 28. 3%— 50. 6% and 19.1%—39.7% compared to that of the two controlled treatments,respectively.( 2) Deep vertically rotary tillage was proved to be beneficial for rain-water infiltration and soil water up-and-down transferring capacity which increased with tillage depth. However,total water consumption amount increased and water use efficiency decreased with tillage depth to some extent. For instance,compared with treatmentⅠ,water consumption amount of treatmentⅡincreased by 5%,and leaf water use efficiency at the 59th and 111th day after sowing and water use efficiency at yield level decreased by 1.6%,1.0% and 2.1%,respectively.( 3) Surface water loss at lower field coverage in early growing stages of crops was inhibited by plastic film mulching after deep vertically rotary tillage. In such cases,total soil consumption was reduced, while soil water up-and-down transferring capacity and water use efficiency were enhanced. Moreover,higher water use efficiency could obtain if deeper new tillage layer was conducted. For instance,water use efficiency at yield level of treatment Ⅲ increased by 8.5% compared with treatmentⅠ,and that of treatment Ⅳ increased by 17.3% compared with treatment Ⅱ. In addition,compared with treatment Ⅲ,leaf water use efficiency at the 59th day and 111th day after sowing of treatment Ⅳ and water use efficiency at yield level increased by 8.3%,7.4% and 5.9% respectively. The results showed that deep vertically rotary tillage can provide a new and effective way to break up the compacted plough pan,solve the shallow tillage layer problem and increase water use efficiency.

Techno-Economic Analysis of Solar Photovoltaic Based Submersible Water Pumping System for Rural Areas of an Indian State Rajasthan

The utilization of solar energy to generate the off-grid electric power is a prominent technology which is utilized in photovoltaic based water pumping system for agriculture and community water supply in this stud. It helps to improve the agricultural productivity which improves the living standard of a farmer and also reduces the CO2 emissions by replacing fossil fuels. This technology replaces 100% fossil fuel system and save CO2 by 14977.57 kg/year. This paper presents fuel replacement and reduction of carbon dioxide on an annual basis and economic analysis of photovoltaic based water pumping system.

A Case Study on Small Scale Hydropower Generation Using Agricultural Water Supply Facilities in Gifu and Aichi Prefectures

A Case Study on Small Scale Hydropower Generation Using Agricultural Water Supply Facilities in Gifu and Aichi Prefectures

Yield and water consumption characteristics of wheat/maize intercropping with reduced tillage in an Oasis region

Higher irrigation quota for conventional farming causes substantial conflicts between water supply and demand in agriculture, and wind erosion near soil surface is one of the major causes of farmland degradation and desertification in arid areas. This research investigated the effect of the amounts of irrigation in combination with tillage practices on soil evaporation (E), water consumption (ET) characteristics, and grain yield performance and water use efficiency (WUE) for wheat (Triticum aestivum L.) intercropped with maize (Zea mays L.) in strip planting in an Oasis region. The field experiment, conducted at Wuwei station during 2008–2010, had two tillage systems (reduced tillage with wheat stubble retention vs. conventional tillage without stubble retention), and three (low, medium, and high) levels of irrigation, in a randomized complete block design. Averaged across three years, soil evaporation with medium and high levels of irrigation was 6.8% and 5.4% greater than that with low level of irrigation, respectively. Total water consumption of wheat/maize crops under the medium and high irrigation levels was 8.5% and 18.5% greater, respectively, than that under low irrigation. However, grain yields were similar under the medium and high levels of irrigation, so was WUE. The effect of tillage on the wheat/maize intercropping was inconsistent across years or among treatments: soil moisture at harvest was 3.0–7.6% greater in the fields with reduced tillage compared with those with conventional tillage in 2008 and 2009, but no difference was found in 2010; the E/ET ratio of reduced tillage was 9% lower than the ratio under conventional tillage in 2008, 3% higher in 2010, but no difference between the two tillage systems in 2009. Across three years, there was a general trend that the WUE of the wheat/maize intercropping system with reduced tillage was greater (by 4–11%) than that with conventional tillage. We conclude that a medium level of irrigation is sufficient to achieve crop yields and WUE equivalent to those under high level of irrigation, provided that a reduced tillage practice is applied to the wheat/maize intercropping in Oasis areas.

Equilibrium sorption studies for Fluoride content in drinking water of Bore wells of Warud Region on Ferronia Elefuntum Fruit Shell

Major water supply for agriculture and domestic purpose in Warud Region is from Upper Wardha and Shekhadari Dam Water. Even then, resident of most of the areas are mainly dependent on bore well water for domestic and Agriculture purpose especially in summer season. Hence large numbers of bore wells are existed. Fluoride content of selected bore-well water in an around of Warud was analyzed in the month of May, 2011. The study reveals that the fluoride concentration is within the permissible limits in few places as prescribed by BIS and WHO. But in some places it is more than prescribed by BIS and WHO. Hence it is essential to remove these excess fluorides by adsorption.