scholarly journals ENVIRONMENTAL FRAGILITY OF THE IRAÍ RIVER BASIN – WATER SUPPLY SOURCE FOR CURITIBA, PARANÁ

FLORESTA ◽  
2021 ◽  
Vol 51 (4) ◽  
pp. 810
Author(s):  
Amanda Köche Marcon ◽  
Christel Lingnau ◽  
Franklin Galvão

This research aimed to compare two methods of determining the environmental fragility of a vital source in the region of Curitiba, Paraná, the Iraí river basin. The determination of the environmental fragility was carried out based on the integration of geological, pedological, geomorphological characteristics and land use, using the emergent fragility and Natural Vulnerability to Soil Loss methods. Most of the Iraí River basin was classified as weak to intermediate environmental fragility by both methods. The methods showed equal fragility ratings in 74% of the basin area. The greatest fragilities were found in areas with recent sedimentation, soils with high instability, slopes higher than 12% and land use areas with low protective potential. The emergent fragility method highlighted the effect of land use, accentuating the fragility of the most vulnerable classes. In contrast, the Natural Vulnerability to Soil Loss method attenuated this land-use effect, softening the vulnerability. The fragility maps indicated that different results might be obtained, especially on the threshold between fragility classes and polygons where land-use makes the environment more vulnerable. Thus, the method selection for determining environmental fragility depends on the relevance necessary for land-use. The emergent fragility method is advantageous for showing the fragility in areas mainly occupied by classes of land use of high vulnerability.

2021 ◽  
Author(s):  
Rohit Kumar ◽  
Benidhar Deshmukh ◽  
Kiran Sathunuri

<p>Land degradation is a global concern posing significant threat to sustainable development. One of its major aspects is soil erosion, which is recognised as one of the critical geomorphic processes controlling sediment budget and landscape evolution. Natural rate of soil erosion is exacerbated due to anthropogenic activities that may lead to soil infertility. Therefore, assessment of soil erosion at basin scale is needed to understand its spatial pattern so as to effectively plan for soil conservation. This study focuses on Parbati river basin, a major north flowing cratonic river and a tributary of river Chambal to identify erosion prone areas using RUSLE model. Soil erodibility (K), Rainfall erosivity (R), and Topographic (LS) factors were derived from National Bureau of Soil Survey and Land Use Planning, Nagpur (NBSS-LUP) soil maps, India Meteorological Department (IMD) datasets, and SRTM30m DEM, respectively in GIS environment. The crop management (C) and support practice (P) factors were calculated by assigning appropriate values to Land use /land cover (LULC) classes derived by random forest based supervised classification of Sentinel-2 level-1C satellite remote sensing data in Google Earth Engine platform. High and very high soil erosion were observed in NE and NW parts of the basin, respectively, which may be attributed to the presence of barren land, fallow areas and rugged topography. The result reveals that annual rate of soil loss for the Parbati river basin is ~319 tons/ha/yr (with the mean of 1.2 tons/ha/yr). Lowest rate of soil loss (i.e. ~36 tons/ha/yr with mean of 0.22 tons/ha/yr) has been observed in the open forest class whereas highest rate of soil loss (i.e. ~316 tons/ha/yr with mean of 32.08 tons/ha/yr) have been observed in gullied area class. The study indicates that gullied areas are contributing most to the high soil erosion rate in the basin. Further, the rate of soil loss in the gullied areas is much higher than the permissible value of 4.5–11 tons/ha/yr recognized for India. The study helps in understanding spatial pattern of soil loss in the study area and is therefore useful in identifying and prioritising erosion prone areas so as to plan for their conservation.</p>


Author(s):  
Andrius Litvinaitis ◽  
Lina Bagdžiūnaitė-Litvinaitienė ◽  
Laurynas Šaučiūnas

On preparing of the first management plans of River Basin Districts have been found that diffuse agricultural pol-lution is one of the most important causing factor and the most significant impact on the quality of water bodies. Diffuse agricultural pollution can be from 45% to 80% of nitrate nitrogen pollution load of water bodies. Pollution is transported by water surface and subsurface runoff through sediments from agricultural territories. This article aims at evaluating of relation between the Quaternary sediments and Land use dissemination. The lithological factor (sandy, loamy, argillaceous) of the basin was calculated based on Quaternary map of Lithuania M 1:200000 and Lithuanian river map M 1:50000. The land-use factor of the basin was calculated based on Corine Land cover M 1:100000 using ArcGis software. In order to carry out more thorough analysis of the determination of relation between the Quaternary sediments and Land use dissemination in given territories, sections of 0–50 m, 50–200 m, 200–500 m, 500–800 m, 800–1000 m and >1000 m were established, calculating the distance in meters from the riverbank.


Hydrology ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 2 ◽  
Author(s):  
Kinati Chimdessa ◽  
Shoeb Quraishi ◽  
Asfaw Kebede ◽  
Tena Alamirew

In the Didessa river basin, which is found in Ethiopia, the human population number is increasing at an alarming rate. The conversion of forests, shrub and grasslands into cropland has increased in parallel with the population increase. The land use/land cover change (LULCC) that has been undertaken in the river basin combined with climate change may have affected the Didessa river flow and soil loss. Therefore, this study was designed to assess the impact of LULCC on the Didessa river flow and soil loss under historical and future climates. Land use/land cover (LULC) of the years 1986, 2001 and 2015 were independently combined with the historical climate to assess their individual impacts on river flow and soil loss. Further, the impact of future climates under Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5) scenarios on river flow and soil loss was assessed by combining the pathways with the 2015 LULC. A physically based Soil and Water Assessment Tool (SWAT2012) model in the ArcGIS 10.4.1 interface was used to realize the purpose. Results of the study revealed that LULCC that occurred between 1986 and 2015 resulted in increased average sediment yield by 20.9 t ha−1 yr−1. Climate change under RCP2.6, RCP4.5 and RCP8.5 combined with 2015 LULC increased annual average soil losses by 31.3, 50.9 and 83.5 t ha−1 yr−1 compared with the 2015 LULC under historical climate data. It was also found that 13.4%, 47.1% and 87.0% of the total area may experience high soil loss under RCP2.6, RCP4.5 and RCP8.5, respectively. Annual soil losses of five top-priority sub catchments range from 62.8 to 57.7 per hectare. Nash Stuncliffe Simulation efficiency (NSE) and R2 values during model calibration and validation indicated good agreement between observed and simulated values both for flow and sediment yield.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
D. L. D. Panditharathne ◽  
N. S. Abeysingha ◽  
K. G. S. Nirmanee ◽  
Ananda Mallawatantri

Soil erosion is one of the main forms of land degradation. Erosion contributes to loss of agricultural land productivity and ecological and esthetic values of natural environment, and it impairs the production of safe drinking water and hydroenergy production. Thus, assessment of soil erosion and identifying the lands more prone to erosion are vital for erosion management process. Revised Universal Soil Loss Equation (Rusle) model supported by a GIS system was used to assess the spatial variability of erosion occurring at Kalu Ganga river basin in Sri Lanka. Digital Elevation Model (30 × 30 m), twenty years’ rainfall data measured at 11 rain gauge stations across the basin, land use and soil maps, and published literature were used as inputs to the model. The average annual soil loss in Kalu Ganga river basin varied from 0 to 134 t ha−1 year−1 and mean annual soil loss was estimated at 0.63 t ha−1 year−1. Based on erosion estimates, the basin landscape was divided into four different erosion severity classes: very low, low, moderate, and high. About 1.68% of the areas (4714 ha) in the river basin were identified with moderate to high erosion severity (>5 t ha−1 year−1) class which urgently need measures to control soil erosion. Lands with moderate to high soil erosion classes were mostly found in Bulathsinghala, Kuruwita, and Rathnapura divisional secretarial divisions. Use of the erosion severity information coupled with basin wide individual RUSLE parameters can help to design the appropriate land use management practices and improved management based on the observations to minimize soil erosion in the basin.


2018 ◽  
Vol 15 (1) ◽  
pp. 1-6
Author(s):  
MAWARDIANA MAWARDIANA ◽  
HELMI HASAN BASRI ◽  
TARMIZI TARMIZI

Krueng Aceh River Basin area (Krueng Jreue Sub-watershed) is a critical watershed, including a priority basin I of 23,218.06 ha. The research was conducted in Krueng Aceh River Basin (DAS), Krueng Jreue Sub-district of Aceh Besar. The study was conducted from December 2015 to February 2016. The research used Descriptive method with field survey and analysis in labotarium. This study aims to analyze the water balance of land in Krueng Jreue Sub-watershed. The methods used in the calculation of the water balance are Thornthwaite & Mather (1957). The results showed that the average water availability in Krueng Jreue Sub-watersheds on the highest land use varieties was found in November and the lowest in July. The rainfall surplus occurred from October to April (7 months) and the deficit occurred from May to September (5 months). In various types of land use, ground water averages are quite available from October to May (8 months), while less available in June until September (4 months). The highest percentage of groundwater was found in the primary forest (47.20%), while the lowest was in the bush (36.36%)


Author(s):  
Hung Pham ◽  
Phu Le Vo ◽  
Trung Van Le

The Da Dang river basin, located in the Upper Part of Dong Nai River, plays a crucial role to protect water resources in the downstream parts. The purpose of this study is to assess and develop a soil erosion map in the Da Dang river basin by using the Revised Universal Soil Loss Equation (RUSLE) combined with remote sensing (RS) and Geographic Information System (GIS). The factors used in the RUSLE equation (R, K, LS, C, and P) were computed by using data obtained from local meteorological stations, topographic maps, soil surveys, and satellite images. The data on water quality (TSS) of 75 surface water samples was deployed at 15 monitoring sites in the river basin in the period of 2012 – 2016, provided by DONRE of Lam Dong. The results showed that 14.41% of the basin area is subjected to a high erosion rate with an extent of 10 tons/ha/year or more. Furthermore, the study also indicated that TSS concentration has a closely correlation with land use practices and the the spatial distribution of soil erosion. These findings are essential information and practical implications for local authorities in formulating provincial planning policy for land use and the management practices of soil and water protection in the Da Dang river basin, a sensitively mountainous area, in the context of climate change.


2021 ◽  
Vol 06 (06) ◽  
Author(s):  
Irma Inashvili ◽  

Based on the application of the Revised Universal Soil Loss Equation (RUSLE) and modern GIS technology (ArcGis 10.2.2.), the article presents a method for calculating the erosion potential of the relief (LS) of the Duruji river basin (north-eastern part of Georgia). The most erosion-hazardous areas have been identified, which is approximately 75.1% of the total area of ​​the Duruji river basin. It has been established that special attention should be paid to a detailed study of the identified erosional areas of the Duruji river basin, taking into account all the influencing factors on soil erosion for the successful design of erosion control measures.


2013 ◽  
Vol 93 (2) ◽  
pp. 41-54
Author(s):  
Predrag Manojlovic ◽  
Milan Srejic ◽  
Ivan Djokic ◽  
Sanja Mustafic ◽  
Tanja Dobrosavljevic

The Rasina River Basin is located on the territory of Central Serbia. The aim of this paper is to determine the amount and spatial distribution of water resources, that is, to establish the participation of altitudinal zones in the formation of the total runoff in the Rasina River Basin area upstream from the "Celije" reservoir. In terms of methodology, determination of water volume is based on four separated petrological-hydrological complexes. Average weighted specific runoff in a given territory is 9 l/s/km2. Metamorphites and magmatites are in the first place per participation in the total water runoff of 42.8 %. The second place belongs to sedimentary rocks that make 39.6 % of the total runoff . Unbound sediments participate in the total runoff value with 10.5 % and limestone with 7.1%.


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