scholarly journals Spatial and temporal variability of nitrogen load from catchment and retention along a river network: a case study in the upper Xin'anjiang catchment of China

2015 ◽  
Vol 47 (4) ◽  
pp. 869-887 ◽  
Author(s):  
Ai Wang ◽  
Lihua Tang ◽  
Dawen Yang
Keyword(s):  
Temporal Variability ◽  
Temporal Distribution ◽  
River Network ◽  
Spatial And Temporal Variability ◽  
Point Source Pollution ◽  
Cropland Area ◽  
Scenarios Analysis ◽  
Retention Characteristics ◽  
Water Resources Protection

Understanding the spatial and temporal variability of nitrogen load and characteristics of retention along a river network is important for land management and water resources protection. This study employs a geomorphology-based non-point source pollution model (GBNP) to simulate the hillslope hydrological processes and transport of sediment and pollutants in the upper Xin'anjiang (XAJ) catchment. Based on the simulation, the spatial and temporal distribution of total nitrogen (TN) load from hillslopes and retention characteristics along the river network are analyzed. The results indicate that annual TN load ranges from 0.54 ton/km2 to 1.88 ton/km2 and is relatively higher during spring and summer. Average TN load positively correlates with irrigated cropland area (r =0.820) and negatively correlates with forest (r = −0.43). Seasonal TN retention ratios in the river network range from 0% to 81%, and streams of order 1 in the Horton–Strahler system have the highest retention ratio and are followed by orders 2, 3, and 4, which are mainly determined by the river hydraulic properties. Results of scenarios analysis demonstrate that TN retention ratios in the river network increase with TN load from hillslopes, but reach a maximum value rapidly, which indicates the limitation of the self-purification capacity of rivers.

scholarly journals FUZZY LOGIC IN THE SPATIAL AND TEMPORAL DISTRIBUTION IN THE QUALITY OF THE BEVERAGE IN CONILON COFFEE

2019 ◽  
Vol 14 (2) ◽  
pp. 163
Author(s):  
Abel Souza Da Fonseca ◽  
Julião Soares De Souza Lima ◽  
Samuel De Assis Silva ◽  
Maria Christina Junger Delôgo Dardengo ◽  
Alexandre Candido Xavier
Keyword(s):  
Spatial Dependence ◽  
Temporal Variability ◽  
Temporal Distribution ◽  
Spherical Model ◽  
Coffea Canephora ◽  
Descriptive Statistics ◽  
Fuzzy Classification ◽  
Spatial And Temporal Variability ◽  
Mouth Feel

<p>The objective in this study was to evaluate the spatial and temporal variability of the beverage quality by applying the fuzzy classification in the final global sensory analysis, for Coffea canephora Pierre ex A. Froehner, in two consecutive harvests. The studied variables were: fragrance (aroma), flavor, bitterness (sweetness), set, balance, cleaning, aftertaste, mouth feel, uniformity, salinity (acidity) and drink (global note). To the average overall scores of the drinks obtained on the cup-tasting at 80.0 points of a sampling, the mesh has applied the function of association of the fuzzy classification linear model to determine the degree of pertinence. The data were analyzed by the descriptive statistics and then by geostatistics to verify the existence and quantify the degree of spatial dependence of the variables. In the interval classified as “very good coffee” is found in the global average grade, in the two harvests. The methodology fuzzy applied in the global beverage note of the coffee conilon seminal made it possible to determine their spatial variability in the same distribution pattern in the two harvests, close ranges, and adjustments to the spherical model, which was confirmed by the spatial correlation of 61.6% among the fuzzy maps for the global score</p>

scholarly journals Spatial and temporal variations of winter discharge under climate change: Case study of rivers in European Russia

2015 ◽  
Vol 368 ◽  
pp. 245-250 ◽  
Author(s):  
E. A. Telegina
Keyword(s):  
Temporal Variability ◽  
Climate Changes ◽  
Temporal Variations ◽  
European Russia ◽  
Spatial And Temporal Variability ◽  
Water Runoff ◽  
Underground Waters ◽  
Winter Runoff ◽  
First Time

Abstract. An important problem in hydrology is the re-evaluation of the current resources of surface and underground waters in the context of ongoing climate changes. The main feature of the present-day changes in water regime in the major portion of European Russia (ER) is the substantial increase in low-water runoff, especially in winter. In this context, some features of the spatial–temporal variations of runoff values during the winter low-water period are considered. Calculations showed that the winter runoff increased at more than 95% of hydrological gauges. Changes in the minimum and average values of runoff during winter low-water period and other characteristics are evaluated against the background of climate changes in the recent decades. The spatial and temporal variability of winter runoff in European Russia is evaluated for the first time.

The role of storm movement in controlling flash flood response: an analysis of the 28 September 2012 extreme event in Murcia, southeastern Spain

2021 ◽  
Author(s):  
A. Amengual ◽  
M. Borga ◽  
G. Ravazzani ◽  
S. Crema
Keyword(s):  
Temporal Variability ◽  
Flash Flood ◽  
Spatial And Temporal Variability ◽  
Hydrological Response ◽  
Catchment Scale ◽  
Flash Flooding ◽  
Southeastern Spain ◽  
Flood Response

AbstractFlash flooding is strongly modulated by the spatial and temporal variability in heavy precipitation. Storm motion prompts a continuous change of rainfall space-time variability that interacts with the drainage river system, thus influencing the flood response. The impact of storm motion on hydrological response is assessed for the 28 September 2012 flash flood over the semi-arid and medium-sized Guadalentín catchment in Murcia, southeastern Spain. The influence of storm kinematics on flood response is examined through the concept of ‘catchment-scale storm velocity’. This variable quantifies the interaction between the storm system motion and the river drainage network, assessing its influence on the hydrograph peak. By comparing two hydrological simulations forced by rainfall scenarios of distinct spatial and temporal variability, the role of storm system movement on the flood response is effectively isolated. This case study is the first to: (i) show through the catchment-scale storm velocity how storm motion may strongly affect flood peak and timing; and (ii) assess the influence of storm kinematics on hydrological response at different basin scales. In the end, this extreme flash flooding provides a valuable case study of how the interaction between storm motion and drainage properties modulate hydrological response.

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