scholarly journals Are Brazilian Catchments Gaining or Losing Water? The  Effective Area of Tropical Catchments

Author(s):  
Dimaghi Schwamback ◽  
Gabriela Chiquito Gesualdo ◽  
Jullian Souza Sone ◽  
Alex Naoki Asato Kobayashi ◽  
Luis Eduardo Bertotto ◽  
...  

Similar to most countries, the Brazilian water resources management considers topographically delineated catchment as a territorial unit for policy implementation. Yet, previous studies have shown that catchments are not hydrologically isolated, and topographic limits often neglect the groundwater boundaries. Thus, studies on effective catchment area are promising for shedding light on inter-catchment groundwater flow. Here, we investigated the deviation between the topographic and effective areas across Brazil. We applied the Effective Catchment Area index (ECI) to 733 Brazilian catchments and identified the most influencing attributes on the ECI by using Principal Component and Random Forest Analyses (PCA and RFA, respectively). Further analysis of consistency was carried out by contrasting the ECI values against the expected range of the Budyko curve considering both topographic and effective catchment areas (classic and adjusted framework). Considering the studied catchments, 15% and 16% of their effective areas were respectively smaller than half (strong losing water condition) and larger than double (strong gaining water condition) of their corresponding topographic areas. The aridity index was the main driving factor and negatively correlated with ECI followed by mean slope, precipitation seasonality, and mean elevation. In general, the more arid biomes in Brazil — the Cerrado and Caatinga — are prone to have smaller effective areas while larger effective areas were mostly found in the Atlantic Forest biome, a humid tropical region with a higher mean elevation. We highlight the potential of adopting a pooling of catchments based on their interconnectivity to minimize management costs while maximizing synergies and lessening trade-offs of water transfer processes. Our results contribute to a better country-scale understanding of hydrological connectivity among catchments and highlight the need to consider the effective catchment area to overcome water-food-energy security challenges on multiple scales.

Author(s):  
Danique Ton ◽  
Sanmay Shelat ◽  
Sandra Nijënstein ◽  
Lotte Rijsman ◽  
Niels van Oort ◽  
...  

Governments worldwide are aiming to increase sustainable mode use to increase sustainability, livability, and accessibility. Integration of bicycle and transit can increase catchment areas of transit compared with walking and thus provide better competition to non-sustainable modes. To achieve this, effective measures have to be designed that require a better understanding of the factors influencing access mode and station choice. At the national/regional level this has been thoroughly studied, but there is a knowledge gap at the urban level. This study aims to investigate which factors influence the joint decision for tram access mode and tram station choice. The joint investigation can identify trade-offs between the access and transit journeys. Furthermore, the effect of each factor on the bicycle catchment area is investigated. Using data from tram travelers in The Hague, Netherlands, a joint simultaneous discrete choice model is estimated. Generally, walking is preferred to cycling. The findings of this study suggest that access distance is one of the main factors for explaining the choice, where walking distance is weighted 2.1 times cycling distance. Frequent cyclists are more likely also to cycle to the tram station, whereas frequent tram users are less inclined to cycle. Bicycle parking facilities increase the cycling catchment area by 234 m. The transit journey time has the largest impact on the catchment area of cyclists. Improvements to the system, such as fewer stops, higher frequency (like light rail transit), or both, therefore would result in a much longer accepted cycling distance.


1993 ◽  
Vol 28 (3-5) ◽  
pp. 101-110 ◽  
Author(s):  
W. v. d. Emde ◽  
H. Fleckseder ◽  
N. Matsché ◽  
F. Plahl-Wabnegg ◽  
G. Spatzierer ◽  
...  

Neusiedlersee (in German) / Fertö tó (in Hungarian) is a shallow lake at the Austro-Hungarian border. In the late 1970s, the question arose what to do in order to protect the lake against eutrophication. A preliminary report established the need for point-source control as well as gave first estimates for non-point source inputs. The proposed point-source control was quickly implemented, non-point sources were - among other topics - studied in detail in the period 1982 - 1986. The preliminary work had shown, based on integrated sampling and data from literature, that the aeolic input outweighed the one via water erosion (work was for totP only). In contrast to this, the 1982 - 1986 study showed that (a) water erosion by far dominates over aeolic inputs and (b) the size of nonpoint-source inputs was assessed for the largest catchment area in pronounced detail, whereas additional estimates were undertaken for smaller additional catchment areas. The methods as well as the results are presented in the following. The paper concludes with some remarks on the present management practice of nonpoint-source inputs.


2010 ◽  
Vol 10 (11) ◽  
pp. 2235-2240 ◽  
Author(s):  
D. G. Hadjimitsis

Abstract. The aim of this study is to quantify the actual urbanization activity near the catchment area in the urban area of interest located in the vicinity of the Agriokalamin River area of Kissonerga Village in Paphos District. Remotely sensed data such as aerial photos, Landsat-5/7 TM/ETM+ and Quickbird image data have been used to track the urbanization activity from 1963 to 2008. In-situ GPS measurements have been used to locate in-situ the boundaries of the catchment area. The results clearly illustrate that tremendous urban development has taken place ranging from 0.9 to 33% from 1963 to 2008, respectively. A flood risk assessment and hydraulic analysis were also performed.


2012 ◽  
Vol 4 (1) ◽  
Author(s):  
Márton Veress ◽  
István Németh ◽  
Roland Schläffer

AbstractThe effects of the intensive rainfall episodes in the years 2009 and 2010 in the Kőszeg Mountains were investigated. Channel profiles were constructed at various times during these periods, which were used to describe the channel changes. We measured the length of the incised and filled sections on multiple occasions. We could establish the degree and the direction of the changes using this data. The sediment veneer that developed in the area of Kőszeg town was mapped and its conditions of development were examined. The erosion and accumulation landforms developed during these years were classified and described. These forms are the following: rills, gullies, alluvial fans and sediment veneer. We distinguished and characterised those which had previously formed, but they were changed or increased (the channels). We established the conditions under which the sediment veneer can develop, furthermore those conditions which can increase the chance of the formation of this landform. These conditions are the following: the high density of roads in the catchment areas of valleys leading to settlements, the great thickness of superficial deposit, and the steep slope of the surface of the catchment area. We created theoretical classification of the morphological environment where the development of sediment veneer may happen and identified settlements with structures which promote or prevent the development of the sediment veneer. We determined the probability of the development of the sediment veneer at some settlements in Kőszeg, and suggestions have been given to decrease the chance of the development of this sediment veneer.


2007 ◽  
Vol 55 (4) ◽  
pp. 93-101 ◽  
Author(s):  
R.P.S. Schilperoort ◽  
H.A.J. Meijer ◽  
C.M.L. Flamink ◽  
F.H.L.R. Clemens

This paper presents considerations for the application of the natural water isotope method on catchment areas. For the estimation of the amount of infiltration and inflow in sewer systems the paper shows two applications in the Netherlands: one successful application on a relatively small catchment area with a simple geo-hydrological groundwater system and one unsuccessful application in an area that shows a large heterogeneity of δ18O values in groundwater. Also, the paper focuses on the validity of the assumption that the isotopic ratios of drinking water are equal to those of strict domestic wastewater. In the transition from drinking water to strict wastewater it is shown that changes in isotopic composition of the water due to evaporation in common household appliances and effects inside the human body are insignificant. However, the presence of high-efficiency condensing boilers in an area can significantly influence the δ18O value of strict wastewater, especially in winter months. This effect should be taken into account when applying the isotope method in such areas.


2017 ◽  
Vol 78 (1) ◽  
pp. 28-38
Author(s):  
Paweł Franczak

Abstract Mountain streams are subjected to the continuous reshaping of their river beds during floods, with the greatest changes occurring during extreme floods caused by sudden and heavy rainfall. River bed transformations during these flash floods are more severe in forested areas, where wooden logs carried by swollen streams are more likely to be deposited on the ground, which in turn leads to the greater accumulation of other transported material and debris. The study was conducted in the Rybny Potok catchment area (Babia Góra National Park). An extreme flash flood occurred on 15–16 May 2014 because of heavy rainfall, which, on 15 May amounted to 138 mm. The total amount of precipitation in the catchment area was 216.5 mm in three days. This resulted in sudden and full streams in spate, contributing to significant geomorphological transformations reaching all the way to the bottom of the river beds. During the flash flood, already established river beds and streams increased in size and many new river courses were formed.


1995 ◽  
Vol 19 (6) ◽  
pp. 340-342
Author(s):  
John M. Kellett

The shift of power from specialist services to the primary care teams has forced the former to examine the value of their hallowed traditions. In psychiatry, and geriatric medicine, the catchment area is a favoured restrictive practice, enabling demand to be regulated to suit the resources of each team. It is time to decide whether this is a practice to be defended and retained or whether, like many other restrictive practices, it is harmful to the consumer.


Author(s):  
O. R. Ilyasov ◽  
S. N. Koshelev ◽  
M. N. Kostomakhin ◽  
I. I. Gavrilin

During the operation of poultry farms a large amount of poultry manure is accumulated. Surface wastewater from landfills for storing poultry manure can become the main source of pollution of natural waters. Thus, one of the most important problems of environmental protection is the development of effective systems for protecting aquatic ecosystems from pollution by waste water generated at landfills for storing poultry manure. The purpose of research was the analysis of water protection systems for treatment of surface wastewater from the territory of poultry farms. The authors of the article consider the problem of protection of water bodies from contamination by surface wastewater from the catchment area of poultry farms. The example of surface wastewater from the catchment area of the poultry farm “Sverdlovskaya” has shown the negative impact on water ecosystems. Our own studies of snow contamination from the catchment area of the poultry farm have shown a high content of not only organic and biogenic substances, but also heavy metals. A biotechnology of wastewater treatment using natural ion-exchange materials, followed by bioregeneration of the latter by higher aquatic vegetation, has been developed. The use of an accumulative phytofilter is an effective method of protecting water ecosystems from contamination by surface wastewater from catchment areas of poultry farms, and the design ensures not only the environmental friendliness of the technology, but also naturally fits into the landscape of the area.


2014 ◽  
Vol 9 (4) ◽  
pp. 526-533
Author(s):  
S. A. Akinseye ◽  
J. T. Harmse

This study focuses on the different physical and chemical water quality parameters of two catchment areas centring on the extent of water pollution in the two basins. Data containing physical and chemical water quality parameters for the Crocodile (West) Catchment area (Gauteng) and the Berg Catchment area (Western Cape) at reconnaissance level of detail were collected from the Department of Water Affairs (DWA) over a period of 5 years, 2007–2011. The relevant data were screened and sorted using the SPSS Software Version 2.0. The data were subjected to ANOVA statistics to search for significant variations in the water quality parameters of concern across the study period in each of the catchment area. The physical and chemical analyses were carried out to determine whether the water quality falls within the total water quality range as prescribed by DWA and WHO for domestic use. Pearson correlation analyses were used to determine the relationship between physical and chemical water quality parameters and the rainfall data over the study period.


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