灌溉排水系统工程

Water is one of the most important inputs for agriculture, human life, livestock, industries and all other living beings. But due to its spatial and temporal variation, its availability, accessibility and affordability poses a great challenge to water users and water managers/planners. The problem becomes more intense due to change in climate, which is being observed more severely now a days. Water can’t be treated as a separate personal entity, rather it is an integral part of the ecosystem and it needs attention of every stakeholder keeping in view an integrated approach. For sustainable development and management of water resources it should be viewed from physical, economic, social, environmental, technical, scientific, professional, institutional, administrative, political and legal angles. Proper strategy needs to be chalked out to combat climate change particularly extreme events like floods, droughts, cyclones, lack of water at critical crop growth stages or excess water in root zone of plant causing decaying of roots and plants. Climate change is not only a challenge for India, but it is challenge for whole world. Due to increasing awareness, all countries of the world are worried and working together to face climate change problem. To combat climate change, there is an urgent need of formulation and timely implementation of appropriate policies by Government to reduce risks of farmers, who not only suffer from complete loss of their crops and lose of food and water for their livestock, but also their livelihood options to satisfy their hunger. This paper discusses the concept of integrated water resources management in order to improve water use efficiency and sustainable use of water resources. Also there is discussion about climate change, its adverse impact and possible implementable strategies to minimize adverse impact on resources.

In hydrological cycle, precipitation initiates the flow and governs the system. The preciseness in the prediction of rainfall will reduce the uncertainty involved in estimating the associated hydrological variables such as runoff, infiltration, and stream flow. Many research works has been channelled towards improving the accuracy of these predictions. ANN is the most widely used neural networks in Integrated Water Resource Management. Most of these models, utilize the strength of data-driven modelling approach. The reliability of these predictions depends on the preciseness in selecting the correlated variables. If the available historical database fails to record the most correlated variable, then reliability on these data-driven approach predictions is questionable. In this paper, an attempt has been made to develop a methodological framework that utilizes the strength of a predictive data-mining analysis (decision tree). The developed decision tree based rainfall prediction model maps the climatic variables, namely; a) temperature, b) humidity, and c) wind speed over the observed rainfall database. The performance of the developed model is evaluated based on three performance indicators (Nash Sutcliffe efficiency, RMSE and MSE). The performance of the developed model is also compared with the well- known data-driven (Artificial Neural Network) based rainfall prediction model.

This study attempted to conduct ArcGIS based diagnostic analysis of Irrigation scheme with intention of introduction of wise use of limited natural resources in case of Upper Awash for irrigation purpose. Experimental site selection criteria were that Boset woreda was one of the most chronically food in-secure districts, availability of secondary data and organizational set up of the irrigation projects. As to the output, simple model to calculate weighted overlay analysis of irrigation suitability was conducted and mapped, and from the map 4454 ha area was identified to be in suitable range for irrigation. Rainfall data records of 10 years (2003-2012) and Awash River stream flow of 21 years (1975-1995) records were adjusted for missing data, checked for consistency by developing double mass curve using three adjacent stations, analyzed for 80% stream flow dependability and was found to be 23.78 m3/s after giving allowance of 30% to downstream water use right. Finally, crop pattern of the study area was organized in CROPWAT 8.0 model along with necessary data such as climate, soil, and crop, cropping pattern. Maximum irrigation requirement with irrigation intensity of 100% was found to 137.5 mm/month in May from which net scheme supply design was calculated to be 5.67 m3/s and assuming 80% application efficiency total scheme supply design was found to be 7.1 m3/s .

Appropriate irrigation practice is relevant for increased crop productivity and conservation of water resources. No or little concern has been given to the necessity and extension of existing irrigation technologies while the impacts of climate change are visible throughout Ethiopia. A field study was carried out for determining optimal irrigation scheduling for maize production at Teppi, South west Ethiopia for three successive years. The objectives of the study were to evaluate the effect of different irrigation regime (different soil moisture depletion levels) on yield and water use efficiency of hybrid maize (BH-140). The treatments were set based on the recommended soil moisture depletion levels for maize (MAD=0.55). Then five levels of soil moisture depletion were selected for evaluation of optimum irrigation scheduling namely SMD1 (60%), SMD2 (80%), SMD3 (100%), SMD4 (120%), and SMD5 (140% of the recommended value, 0.55). The result indicated that SMD4 has significantly (P<0.05) increased the grain yield and water use efficiency of maize crop on a clay loam textured soil. In addition the total crop water requirement was 535.60 mm. However, the reduced soil moisture depletion level below the recommended values (SMD1 and SMD2) has resulted lower both grain yield and crop water use efficiency. This study also revealed that the appropriate irrigation interval at each crop growth stage should be identified for ease of work to the users.

Deficit irrigation (DI) improves water productivity and irrigation management practices resulting in water saving by maintaining soil moisture content below optimum level throughout growth season. Field study was carried out on clay loam soil at Melkassa Agricultural Research Center, Ethiopia with the objectives to estimate water productivity of onion and evaluate the effect of water deficit on onion yield and quality using drip irrigation. The experiment contained five DI treatments of 90%, 80%, 70%, 60%, and 50% Crop water use (ETc) and the control (100% ETc) laid out in RCBD design with three replications. Irrigation water was applied at allowable soil moisture depletion (p=0.25) of the total available soil moisture throughout the crops growth stage. Statistical analysis revealed that plant height was not affected by the level of DI while, leaf number, bulb diameter, marketable bulb yield and total bulb yield had shown a highly significant (P<0.01) differences among DI treatments. The highest bulb diameter was observed from a control treatment that was significantly different to all other treatments. The highest total bulb yield of 15,690 kg/ha was observed from a control treatment which was not significantly different with treatment receiving 90% ETc. Highest water productivity of onion bulb yield was observed from treatment receiving 70% ETc and better onion bulb diameter was observed from treatment receiving 100% ETc to 70% ETc. The yield response factor ranged between 0.8 and 1.7. Thus, DI practices should be avoided for Ky values that are less than unity. Considering yield response factors (Ky) is limiting factor, 80% ETc application was a marginal and beyond that yield losses are intolerable. Thus, the practice of DI application up to 20% saved 45 to 108 mm depth of water from the gross onion irrigation water requirement.

Two field experiments were conducted to study fruit yield and physiological responses of field grown tomato. The first experiment was conducted with container grown during rainy season by combining three factors namely, two levels of N (0 and 25 kg N ha-1), and two levels of P (0 and 23 kg P ha-1) fertilizers and with six locally available media mix ratios (MR). The experiment was laid down on CRBD in a factorial arrangement and replicated three times. The second experiment was conducted under drip irrigation during hot dry season with three levels of daily irrigation applications: full irrigation, 80% and 60% of daily ETc irrigations. Data on marketable, unmarketable and total fruit yield were recorded and some physiological responses: quantum yield, leaf chlorophyll content and fluorescence, and stomatal conductance were assessed from sample plant leaves using various sensors. The results of container grown experiment indicated that use of combinations of starter N and MR showed a significant effect (P<0.05) on the marketable fruit yield, similarly use of media mixtures had highly significant (P<0.01) influence on the unmarketable fruit yield and finally use of media mix ratio showed a highly significant effect (P<0.01) on the total fruit yield of container grown tomato. MR3 yielded the highest total fruit yield while MR6 gave the lowest total fruit yield. Application of starter N, P or media mix did not bring any combined effect (P<0.01) on the leaf chlorophyll content. However, application of starter N caused a highly significant (P<0.01) effect on leaf quantum yield. The results of drip irrigated experiment indicated that use of various irrigation depth brought a significant (P<0.01) effect on the marketable yield of tomato. The highest fruit yield was recorded in response to full irrigation, while the lowest marketable fruit yield was recorded from 60% of full irrigation. Irrigation depth significantly (P<0.01) affected the tomato leaf chlorophyll content. The highest irrigation level increased leaf chlorophyll content and lowest irrigation depth reduced leaf chlorophyll content. Irrigation depth brought significant (P<0.01) effect on the stomatal conductance as irrigation depth decreased, leaf stomatal conductance was highly reduced. Measuring quantum yield, leaf chlorophyll content, and fluorescence and stomatal conductance of tomato plant there is indicated direct relation with yield performance that would give instant improvement of management practices of the crop. Thus further research is required to fine tune and use of this physiological response with the crop yield.

This study focused on the contributions of social networking in accessing resource for irrigation farming among farming households in north central Nigeria. Systematic random sampling was used to select 194 respondents from Oke-oyi and shonga (Kwara State) and Ejiba (Kogi State). Data were obtained using structured questionnaire. The data were analyzed using descriptive statistics and Pearson Product Moment Correlations. The findings indicated that market information with the mean score of 2.75, was the most important contribution of social networking in accessing resource for irrigation farming while lack of input with mean score of 2.27 was the highest ranked constraint faced by the farmers using irrigation for crop production. The result of correlation analysis revealed that there was no significant relationship between the contributions of social networking in accessing resources for irrigation and the constraints faced by the farmers using irrigation for crop production. Based on this results, it is therefore recommended that there should be creation of awareness on various opportunities that are available for irrigation farmers participating in social networking.

Precise estimation of reference evapotranspiration (ETo) and crop evapotranspiration (ETc) on a daily basis is important to apply water through drip system for crops grown in the greenhouse. Crop coefficients and crop water requirement were determined for the Dutch roses cultivated in the greenhouse and open field for the sub-humid climatic conditions of Kharagpur, India. Reference evapotranspiration (ETo) was estimated using the method suggested by FAO-56. The crop ET was determined using soil water balance approach. The soil moisture data was collected using TDR moisture meter at three depths. The maximum daily values of Crop ET were 4.99 and 5.28 mm day-1 for greenhouse and open field conditions respectively. Maximum values of crop coefficient were found during conjunction period of mid-season and late season stage of the crop growth period. During different growth stages of rose, crop coefficient values were found in the range from 0.48 to 0.96 and 0.59 to 1.01 for greenhouse and open field conditions. The Dutch rose planted in 200 μ diffused poly film cladded greenhouse and given 100% water requirement through drip irrigation resulted in maximum number of flowers/m2 (212.3) annually. Total annual water requirement of rose plant was 999.51 mm and 1210.94 mm for greenhouse and open field condition respectively.

Estimation of evapotranspiration is necessary for efficient water management and crop planning. Fifteen different methods of ET0 estimation were employed to compute daily reference evapotranspiration for the period 2010 to 2014. In the absence of reliable open pan evaporimeter data, FAO-56 Penman Monteith method was considered as one of the reliable method of ET0 estimation. The results showed that mean weekly evapotranspiration values obtained from Penman-Monteith method were very closer to FAO-56 Penman-Monteith method and values from all the other methods except FAO- 24 Pan, Christiansen Pan and Hargreaves methods generally predicted higher values of mean weekly daily ET0 in comparison to FAO-56 Penman-Monteith method. The analysis shows that mean weekly daily ET0 estimates of combination methods resulted better ET0 estimates than radiation, and temperature and evaporation methods. Weekly ET0 values estimated by FAO-56 Penman-Monteith method were found to vary in the range of 1.3 mm/day to 6.7 mm/day. Average annual reference evapotranspiration was found as 1517.1 mm.