Biological and Agricultural Engineering

Rainfall Wet and dry spells Multifractal analysis Wavelet analysis s u m m a r y A large set of monthly precipitation data from 43 stations throughout Texas was employed to investigate the spatial variability in the multiscaling properties of wet and dry spells. Special emphasis was given to dry spells which are related to meteorological droughts. Scaling properties deduced from the analysis of dry spells can be used in drought modeling and multiscale temporal variability of droughts. Using moment scaling exponents, scaling properties of wet and dry spells were examined for a median truncation level. No coherent regional differences were found from the spatial depiction of scaling parameters. Wet and dry spells showed different tendencies in simple scaling and multiscaling throughout the study area. Also, significant low frequency patterns of precipitation were found when the wavelet transform was used. Investigation of the relationship between scaling properties and significant cycles of precipitation data showed that annual cycles may contribute to the occurrence of simple scaling mechanism in wet and dry spell sequences. Such characterization of sequences of wet and dry spells is essential for addressing a multitude of hydrological problems, including estimation of flood and drought frequencies, construction of rainfall and runoff relationships, agricultural planning, to name but a few.

Rainfall Wet and dry spells Multifractal analysis Wavelet analysis s u m m a r y A large set of monthly precipitation data from 43 stations throughout Texas was employed to investigate the spatial variability in the multiscaling properties of wet and dry spells. Special emphasis was given to dry spells which are related to meteorological droughts. Scaling properties deduced from the analysis of dry spells can be used in drought modeling and multiscale temporal variability of droughts. Using moment scaling exponents, scaling properties of wet and dry spells were examined for a median truncation level. No coherent regional differences were found from the spatial depiction of scaling parameters. Wet and dry spells showed different tendencies in simple scaling and multiscaling throughout the study area. Also, significant low frequency patterns of precipitation were found when the wavelet transform was used. Investigation of the relationship between scaling properties and significant cycles of precipitation data showed that annual cycles may contribute to the occurrence of simple scaling mechanism in wet and dry spell sequences. Such characterization of sequences of wet and dry spells is essential for addressing a multitude of hydrological problems, including estimation of flood and drought frequencies, construction of rainfall and runoff relationships, agricultural planning, to name but a few.

Data regarding trace element concentrations and fluxes in suspended sediments and bedload are scarce. To fill this gap and meet the international need to include polluted rivers in future world estimation of trace element fluxes, this study aimed to determine the trace element fluxes in suspended sediment and bedload of an environmentally impacted river in Brazil. Water, suspended sediment, and bedload from both the upstream and the downstream cross sections were collected. To collect both the suspended sediment and water samples, we used the US DH-48. Bedload measurements were carried out using the US BLH 84 sampler. Concentrations of Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were determined by inductively coupled plasma (ICP-OES). As and Hg were determined by an atomic absorption spectrophotometer (AA-FIAS). The suspended sediments contributed more than 99 % of the trace element flux. By far Pb and to a less extent Zn at the downstream site represents major concerns. The yields of Pb and Zn in suspended sediments were 4.20 and 2.93 kg km 2 year −1 , respectively. These yields were higher than the values reported for Pb and Zn for Tuul River (highly impacted by mining activities), 1.60 and 1.30 kg km 2 year −1 , respectively, as well as the Pb yield (suspended+dissolved) to the sea of some Mediterranean rivers equal to 3.4 kg km 2 year −1 . Therefore, the highest flux and yield of Pb and Zn in Ipojuca River highlighted the importance to include medium and small rivers-often overlooked in global and regional studies-in the future estimation of world trace element fluxes in order to protect estuaries and coastal zones.

The time of concentration is an important parameter for predicting peak discharge at the basin outlet and for designing urban infrastructure facilities. In studying the hillslope response, employing hydraulic equations of flow, the shape of the hillslope geometry has often been assumed as rectangular and planar. However, natural hillslopes have complex topographies whose shapes are characterized by irregularly spaced contour lines. Recently, kinematic wave time of concentration has been derived for rectangular and curved parallel hillslopes. This paper extends this work to hillslopes of complex planform geometry, considering the degree of divergence or convergence of the hillslope. The extended formulation consists of only one equation that is valid for both divergent/convergent surfaces and for concave/ convex hillslope profile, and is compared with the formulations for plane convergent and plane divergent surfaces previously introduced. Results are compared with those already available in the literature, which were obtained by using the nonlinear storage model applied to the same complex hillslopes. individual papers. This paper is part of the Journal of Irrigation and Drainage Engineering, © ASCE, ISSN 0733-9437. © ASCE 04015059-1 J. Irrig. Drain Eng. J. Irrig. Drain Eng., 2016, 142(3): 04015059 Downloaded from ascelibrary.org by Texas A&M University on 04/22/16. Copyright ASCE. For personal use only; all rights reserved. © ASCE 04015059-2 J. Irrig. Drain Eng. J. Irrig. Drain Eng., 2016, 142(3): 04015059 Downloaded from ascelibrary.org by Texas A&M University on 04/22/16. Copyright ASCE. For personal use only; all rights reserved. © ASCE 04015059-10 J. Irrig. Drain Eng.

The flow duration curve (FDC) of a riveris one of the important parameters for the hydrological investigation of hydroelectric plants. Computation of the hydroelectric plant capacity and power production requires the determination of relative and cumulative frequenciesof different river discharges. Ab-Terki is one of the sub-basins of Bazoft River, located in Chaharmahal and Bakhtiari province, Iran, next to Koohrang basin. It is located between eastern longitudes of 49ᵒ54' to 50ᵒ 5' and northern latitudes of 32ᵒ 19' to 32ᵒ 24'. Morphological conditions, sloping limestone structures, and characteristics of karstic cracks in the basin have led to the formation of large springs in the eastern and western foothills of Zardkooh Mountain. In order to determine the FDCs of Ab-Terki River,3-year daily discharge and 24-year mean monthly discharge of Gooshe-pol station were used. Then, the probabilities of discharges were analyzed using Hyfa and Rank Plot numerical codes and finally, the discharge of Ab-Terki River corresponding to 95% probability was determined.

Water user cooperative (WUC) is an organization for promoting optimum use and management of water, emphasizing the participation of all beneficiary groups.  The aim of this study is to determine the factors that deter WUC from being successful in accomplishing its objective in Jarghoyeh Region, Isfahan Province, Iran. These factors are enumerated through five indices: notification, participation, economic incentives, social incentives, and organization-farmer communication, using fuzzy regression model and symmetric and non-symmetric fuzzy triangular numbers. The values of indices estimatedin the study indicate that economic incentivesneither have been defined for the beneficiary groups norattemptshavebeen made in this regard in practice.  Influences of other indices on forming cooperatives are poorly evaluated.

To investigate and measurement of different variables effects such as type of fibers, weight percent (ratio of yarn dry weight and soil dry weight) and length of fibers on loading improvement of reinforcement weak sandy soil (with random distribution), was used artificial yarn such as polypropylene in CBR experiment. Conclusion of indicator in these experiments is increase of shear strength of sand mix with random distribution in 13.8 percent of humidity. But in further humidity, behavior of reinforcement becomes different. Lengthening of fibers till 12 millimeters, increases the loading strength by changing the percent of fibers; while more lengthening, leads up to reduce strength.

Keywords:
Silty-sandy soil, Soil stabilization, polypropylene fibers, CBR.

Determine the flow resistance parameters are important in hydraulic calculations of mountain area with steep slops. The purpose of this study is investigation the effect of slope, speed, depth and size of roughness on the manning roughness coefficient in this shallow stream region. This is an experimental study about manning roughness determined for mountain areas covered by particles in three different sizes and three gradients for different hydraulic conditions in a flume of 8.3m long, 0.8m width and 0.5m height under bed slope of 0.0005. At the end of flow changes against the Manning roughness coefficient are shown, which includes above hydraulic parameters and discussed.


Keywords:

Shallow waters; Manning coefficient; Mountain areas

Accurate data and timely information regarding the existing land-uses is needed to manage the natural landscapes effectively. The information related to land-use changes constitutes the basic element in management of natural resources. In fact, the awareness about patterns of land-use changes is conductive of ecosystem toward balance. Therefore, the need to detect, plan and predict such changes in an ecosystem is of great importance. In order to discover these changes, the application of multi-temporal remote sensing data (RS) and geographical information system (GIS) provides the possibility of valuable analysis. In this paper, two images, i.e. ETM+ 2002 and OLI 2015 were used for Zanjan city. To map the pattern of changes, at first the coordinates of two images were integrated, andafter the atmospheric corrections, the considered area was classified to four classes including residential areas, road network, vegetation and other regions using the maximum likelihood method. Then,Post classification and overlapping methods were used to detect changes. The results show that the urban expansion has increased during 13 years. The expansion of Zanjan City has been inclined more toward north and north –west affecting the barren lands, while the garden lands in the south has been less influenced by urban expansion. 

Keywords: Change detection, Land-use, Remote sensing, GIS, Landsat, Zanjan city