scholarly journals Rapid Assessment of Hillslope Erosion Risk after the 2019–2020 Wildfires and Storm Events in Sydney Drinking Water Catchment

2020 ◽  
Vol 12 (22) ◽  
pp. 3805
Author(s):  
Xihua Yang ◽  
Mingxi Zhang ◽  
Lorena Oliveira ◽  
Quinn R. Ollivier ◽  
Shane Faulkner ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Erosion Rate ◽  
Google Earth ◽  
Geographical Information ◽  
Rainfall Erosivity ◽  
Landsat 8 ◽  
Storm Events ◽  
Erosion Risk ◽  
Water Catchment

The Australian Black Summer wildfires between September 2019 and January 2020 burnt many parts of eastern Australia including major forests within the Sydney drinking water catchment (SDWC) area, almost 16.000 km2. There was great concern on post-fire erosion and water quality hazards to Sydney’s drinking water supply, especially after the heavy rainfall events in February 2020. We developed a rapid and innovative approach to estimate post-fire hillslope erosion using weather radar, remote sensing, Google Earth Engine (GEE), Geographical Information Systems (GIS), and the Revised Universal Soil Loss Equation (RUSLE). The event-based rainfall erosivity was estimated from radar-derived rainfall accumulations for all storm events after the wildfires. Satellite data including Sentinel-2, Landsat-8, and Moderate Resolution Imaging Spectroradiometer (MODIS) were used to estimate the fractional vegetation covers and the RUSLE cover-management factor. The study reveals that the average post-fire erosion rate over SDWC in February 2020 was 4.9 Mg ha−1 month−1, about 30 times higher than the pre-fire erosion and 10 times higher than the average erosion rate at the same period because of the intense storm events and rainfall erosivity with a return period over 40 years. The high post-fire erosion risk areas (up to 23.8 Mg ha−1 month−1) were at sub-catchments near Warragamba Dam which forms Lake Burragorang and supplies drinking water to more than four million people in Sydney. These findings assist in the timely assessment of post-fire erosion and water quality risks and help develop cost-effective fire incident management and mitigation actions for such an area with both significant ecological and drinking water assets. The methodology developed from this study is potentially applicable elsewhere for similar studies as the input datasets (satellite and radar data) and computing platforms (GEE, GIS) are available and accessible worldwide.

Near real-time monitoring of post-fire erosion after storm events: a case study in Warrumbungle National Park, Australia

2018 ◽  
Vol 27 (6) ◽  
pp. 413 ◽  
Author(s):  
Xihua Yang ◽  
Qinggaozi Zhu ◽  
Mitch Tulau ◽  
Sally McInnes-Clarke ◽  
Liying Sun ◽  
...  
Keyword(s):  
Real Time ◽  
National Parks ◽  
Spatial Data ◽  
Soil Loss ◽  
National Park ◽  
Field Measurements ◽  
Geographical Information ◽  
Rainfall Erosivity ◽  
Storm Events ◽  
Erosion Risk

Wildfires in national parks can lead to severe damage to property and infrastructure, and adverse impacts on the environment. This is especially pronounced if wildfires are followed by intense storms, such as the fire in Warrumbungle National Park in New South Wales, Australia, in early 2013. The aims of this study were to develop and validate a methodology to predict erosion risk at near real-time after storm events, and to provide timely information for monitoring of the extent, magnitude and impact of hillslope erosion to assist park management. We integrated weather radar-based estimates of rainfall erosivity with the revised universal soil loss equation (RUSLE) and remote sensing to predict soil loss from individual storm events after the fire. Other RUSLE factors were estimated from high resolution digital elevation models (LS factor), satellite data (C factor) and recent digital soil maps (K factor). The accuracy was assessed against field measurements at twelve soil plots across the Park and regular field survey during the 5-year period after the fire (2013–17). Automated scripts in a geographical information system have been developed to process large quantity spatial data and produce time-series erosion risk maps which show spatial and temporal changes in hillslope erosion and groundcover across the Park at near real time.

scholarly journals Numerical Modeling for Gully Erosion in the North of Algeria based on Data of Remote Sensing and Geographic Information Systems

2017 ◽  
Vol 25 (1) ◽  
pp. 37-63
Author(s):  
mohammad abbas daoudi mohammad abbas daoudi
Keyword(s):  
Remote Sensing ◽  
Multivariate Analysis ◽  
Information Systems ◽  
Geographical Information Systems ◽  
Univariate Analysis ◽  
Probabilistic Approach ◽  
Geographical Information ◽  
Rainfall Erosivity ◽  
Erosion Risk ◽  
The North

The problems of soil erosion are largely widespread in the countries of the Mediterranean basin. The process of gullying is a complex phenomenon with disastrous consequences. It particularly affects northern Algeria, decreasing the potentialities of the water tanks, reducing cultivable lands availability and degrading infrastructures. Therefore, this work studies the analysis and the prediction of gullying erosion by using a probabilistic approach based on multisource data. The objective of this search is to answer to the three following questions: i) which factors support the process of gullying ? ii) how does a process of gullying develop? iii) which are the zones favourable to gullying ? Works are undertaken on the catchment area of the Isser River. We focused the applications on the upstream part of the basin. In this research, we study a North-South transect which corresponds to three under-basins slopes. The choice of these tests areas answers to four criteria defined in our method: the representativeness, the homogeneity, the availability of former data and, finally, the accessibility. After the completion of the multisource data, modelling and multivariate analysis for the prediction of gullying. The combination factor-process by the univariate analysis allows on the one hand, to highlight the variables controlling the process of gullying, and on the other hand, to analyse the variables on a hierarchical basis and to know their degree of influence. The multivariate analysis, by the logistic regression model (LRM), enabled us to select the significant variables and to locate the most favourable zones for the process of gullying. The validation of the models is evaluated using the curves of lift spin. The results suggest that the factors highlighted by the model to be most influential on gullying erosion are: the lithology, the slope, the morphopedology, the rainfall erosivity and the land cover. The synthesis of this approach is illustrated in the form of charts of gullying erosion risk maps in four classes of probability. The assessment of the study shows the fundamental interest of this approach using geographical information systems and remote sensing, in particular for the watersheds of the southern Mediterranean, with the possibility of extending this methodology to other regions.

scholarly journals Water quality assessment of the Triassic aquifer, SE Tunisia, for drinking water supply

2019 ◽  
Vol 98 ◽  
pp. 09002
Author(s):  
Meriem Ameur ◽  
Fadoua Hamzaoui-Azaza ◽  
Moncef Gueddari
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Chemical Composition ◽  
Water Samples ◽  
Geographical Information Systems ◽  
Water Quality Assessment ◽  
Geographical Information ◽  
Multivariate Statistical ◽  
Aquifer System

The Triassic aquifer is located in southereastern Tunisia, in the Medenine region, and being part of Jeffara's multilayer aquifer system. The aquifer is currently overexploited with an exploitation rate of 163%, which led to a generalized drop in the piezometric level in the order of 20 cm/year. This study applied conventional techniques such as hydrochemical compositions, multivariate statistical methods and Geographical Information Systems (GIS). To better identify the processes controlling the hydrogeochemical evolution of groundwater quality of Triassic aquifer and its suitability for drinking uses, 14 well water samples from the Triassic aquifer were analysed for physical character and chemical composition. In the groundwater, the respective order of cation and anion concentration was Na>Ca>Mg>K and SO4>Cl>HCO3. The chemical data of water samples from the study area presented by plotting on a Piper diagram reveals the predominance of two hydrochemical types: a Na-Ca-Mg-SO4 facies and a Na-Ca-Mg-Cl-SO4 facies. Analytical results demonstrate that the chemical composition of groundwater in Triassic aquifer is strongly influenced by residence time and flow path. Water quality deteriorates going from southwest to northeast across the region, coincident with the appearance a clay layer limiting the infiltration of rainwater. The majority of ions are above the maximum desirable limits recommended for drinking water by WHO guidelines and Tunisian Standards (NT.09.14). Based on the Water Quality Index (WQI), 36% of water samples of the Triassic aquifer are classified as "poor water" and they cannot be used for drinking purposes without prior treatment.

scholarly journals ESTIMATE THE ANNUAL SOIL LOSS IN KUMMATTIPATTI NADI WATERSHED USING RUSLE MODEL THROUGH GEOSPATIAL TECHNOLOGY

2020 ◽  
Vol 46 (2) ◽  
pp. 75-82
Author(s):  
Suraj Shaikh ◽  
Masilamani Palanisamy ◽  
Abdul Rahaman Sheik Mohideen
Keyword(s):  
Soil Erosion ◽  
Soil Loss ◽  
Tamil Nadu ◽  
Management Strategies ◽  
Geographical Information ◽  
Rainfall Erosivity ◽  
Agricultural Activity ◽  
Erosion Risk ◽  
Factor C ◽  
Conservation And Management

Soil erosion and soil loss is one of the common problems threatening the environment. This degrading phenomenon declines the soil fertility and significantly affects the agricultural activity. As a consequence, the productivity of soil is affected unquestionably. In this reason, there is a basic need to take up conservation and management measures which can be applied to check further soil erosion. Even though, soil erosion is a mass process spread cross the watershed, it is not economically viable to implement conservation techniques to the entire watershed. However, a method is a pre-requisite to identify the most vulnerable areas and quantify the soil erosion. In this study, Revised Universal Soil Loss Equation (RUSLE) has been accepted to estimate soil erosion in the Kummattipatti Nadi watershed part of the Coimbatore district of Tamil Nadu, India. This model has several parameters including runoff-rainfall erosivity factor (R), soil erodability Factor (K), topographic factor (LS), cropping management factor (C), and support practice factor (P). All these layers are prepared through geographical information system (GIS) by using various data sources and data preparation methods. The results of the study shows that the annual average soil loss within the watershed is about 6 t/ha/yr (metric ton per hectare per year). Higher soil erosion is observed in the land use classes of gullied wasteland, open scrub forest and degraded plantation. The soil erosion risk is extremely higher on the steep slopes and adjoining foothills. The proper conservation and management strategies has to be implement in this watershed for the development.

scholarly journals ESTIMATION OF ANNUAL AVERAGE SOIL LOSS, BASED ON RUSLE MODEL IN KALLAR WATERSHED, BHAVANI BASIN, TAMIL NADU, INDIA

2015 ◽  
Vol II-2/W2 ◽  
pp. 207-214 ◽  
Author(s):  
S. Abdul Rahaman ◽  
S. Aruchamy ◽  
R. Jegankumar ◽  
S. Abdul Ajeez
Keyword(s):  
Soil Erosion ◽  
Soil Loss ◽  
Tamil Nadu ◽  
Rainfall Erosivity ◽  
Storm Events ◽  
Rill Erosion ◽  
Slope Length ◽  
Conservation Practice ◽  
Erosion Risk ◽  
Wide Range

Soil erosion is a widespread environmental challenge faced in Kallar watershed nowadays. Erosion is defined as the movement of soil by water and wind, and it occurs in Kallar watershed under a wide range of land uses. Erosion by water can be dramatic during storm events, resulting in wash-outs and gullies. It can also be insidious, occurring as sheet and rill erosion during heavy rains. Most of the soil lost by water erosion is by the processes of sheet and rill erosion. Land degradation and subsequent soil erosion and sedimentation play a significant role in impairing water resources within sub watersheds, watersheds and basins. Using conventional methods to assess soil erosion risk is expensive and time consuming. A comprehensive methodology that integrates Remote sensing and Geographic Information Systems (GIS), coupled with the use of an empirical model (Revised Universal Soil Loss Equation- RUSLE) to assess risk, can identify and assess soil erosion potential and estimate the value of soil loss. GIS data layers including, rainfall erosivity (R), soil erodability (K), slope length and steepness (LS), cover management (C) and conservation practice (P) factors were computed to determine their effects on average annual soil loss in the study area. The final map of annual soil erosion shows a maximum soil loss of 398.58 t/ h<sup>-1</sup>/ y<sup>-1</sup>. Based on the result soil erosion was classified in to soil erosion severity map with five classes, very low, low, moderate, high and critical respectively. Further RUSLE factors has been broken into two categories, soil erosion susceptibility (A=RKLS), and soil erosion hazard (A=RKLSCP) have been computed. It is understood that functions of C and P are factors that can be controlled and thus can greatly reduce soil loss through management and conservational measures.

scholarly journals Flood Management Based on The Potential Urban Catchments Case Study Padang City

2021 ◽  
Vol 5 (1) ◽  
pp. 49-54
Author(s):  
Dwi Marsiska Driptufany ◽  
Quinoza Guvil ◽  
Desi Syafriani ◽  
Dwi Arini
Keyword(s):  
Land Use ◽  
Catchment Area ◽  
Water Infiltration ◽  
Geographical Information ◽  
Landsat 8 ◽  
Water Catchment Area ◽  
Catchment Areas ◽  
Wide Range ◽  
Urban Catchments ◽  
Water Catchment

The water catchment area also indirectly impacts on flood control for areas that are lower than it because rainwater does not fall to the lower areas but is absorbed as groundwater. Increased development of Padang City will be inversely proportional to the reduction in water catchment areas and become an area that is impermeable that makes rainwater stagnate on the surface and flood occurs. The development of remote sensing technology and geographic information systems has made it possible to study the spatial patterns of potential water catchment areas in a wide range, including mapping the potential of water catchment areas in Padang City. This study aims to analyze the condition of the availability of water catchment areas for controlling water management and flood disasters in Padang City based on data on spatial parameters such as rainfall data, slope, soil type maps, and land use obtained from Landsat 8 OLI imagery data. This study uses the scoring and overlay method with the Geographical Information System. The results show that the condition of the water catchment area in the western part of Padang City have been critical, reaching 18.29% of the total area of ​​Padang City, this is due to land use that has undergone a change of function. If the water infiltration condition worsens (critical), it gives more opportunities for flooding and inundation. Thus the areas with the potential for water absorption which are categorized as critical and very critical in the research location can be said to be areas that are potentially prone to flooding and inundation, because the ground surface is no longer able to absorb water. Monitoring the potential of water catchment areas is one form of flood mitigation efforts.

scholarly journals Lichen communities as a multiscale correlative indicator of elevational and land use-land cover gradients in the Himalayas

2021 ◽  
Author(s):  
Himanshu Rai ◽  
Roshni Khare ◽  
Deepak Upadhyay ◽  
Rajan Kumar Gupta ◽  
Avinash B. Ade ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Geographical Information Systems ◽  
Elevation Gradient ◽  
Google Earth ◽  
Geographical Information ◽  
Landsat 8 ◽  
Land Use Land Cover ◽  
Srtm Dem ◽  
Elevation Gradients

Abstract Elevation and land use/ land cover (LULC) plays an important role in the diversity of lichens in the Himalayas. The elevation gradients and LULC can be remotely assessed using remote sensing (RS) and geographical information systems (GIS). The current study was done in the Chopta-Tungnath landscape in the Kedarnath wildlife sanctuary, western Himalaya, India. Digital elevation modelling of the study area was done using shuttle radar topography mission data (SRTM-DEM) processed in Esri ArcGIS® ArcMAPTM 10.5, to assess the elevation gradient of the study area and selection of four lichen sampling sites. The LULC maps of the study area were prepared using Landsat 8 and Google Earth Pro 7.3.2.5776 imagery processed using LeicaTM ERDAS IMAGINE® 9.2. An elevation gradient of 2750 m to 3703m was recorded by SRTM-DEM. The LULC analysis resulted in five LULC classes of which the four sampling sites fall in the 3 LULC classes. The principal component analysis (PCA), used to analyse the lichen communities along the RS-GIS recognized LULC classes. The study found lichen communities to be a proxy to the LULC classes in the Himalayas with clear gradients of growth forms and habitat subsets along the increasing elevation gradient.

Soil erosion hazard map for river basin managers: An example for the water bodies of the Loire river basin (France)

2020 ◽  
Author(s):  
Clément Chabert ◽  
Francesca Degan ◽  
Sébastien Salvador-Blanes ◽  
Olivier Evrard ◽  
Rosalie Vandromme ◽  
...  
Keyword(s):  
Water Quality ◽  
Soil Erosion ◽  
River Basin ◽  
Water Bodies ◽  
Rainfall Erosivity ◽  
Erosion Risk ◽  
Erosion Hazard ◽  
Management Plans ◽  
The Impact ◽  
Loire River

Abstract: Soil erosion on agricultural land is associated with deleterious off-site impacts including the siltation andthe pollution of the receiving water bodies. To better manage this situation, local/regional water agencies needspatially-distributed information to compare the sensitivity to erosion of the areas draining into these water bodiesand supplying the vast majority of sediment and associated pollutants leading to this water quality impairment.These soil erosion hazard maps are now often included in the latest versions of the basin management plans thatmust be designed to meet the water quality objectives of the EU Framework Directive. However, the resolution ofthese maps is often too coarse to meet the practical needs of these agencies. Accordingly, the current research usedthe latest input databases to improve the MESALES model outputs in one of the largest French River basins (Loire,117,000 km2), with the implementation of three main modifications. First, the seasonal variations of land coverwere incorporated into the model through a revised set of expert rules based on the agricultural census data. Second,the discrimination of the soil textures was improved within the infiltration and erodibility module of the model.Third, variations in rainfall erosivity across the study area were described taking into account the latest erosivitymap available at the European scale. Then, the model results obtained with the updated model version were comparedwith those generated by the previous version. Overall, the simulated soil erosion hazard changed for 35% ofthe pixels of the Loire River basin, with a significant increase of the lowest hazard classes during all seasons exceptsummer. When aggregating the results at the scale of water bodies, the simulated erosion hazard changed for 49%of these management units. Although 28% of these water bodies were associated with a lower hazard, 23% of theriver systems were attributed a higher erosion risk. The implications of these model/map revisions for the localdecision makers were discussed, taking the strategy of concentrating the management budget on those water bodiesassociated with the highest erosion risk as an example. In the future, this model could be used to compare the soilerosion hazard in contrasted regions of Europe and to simulate the impact of management plans designed todecrease this risk to support the decisions of water agencies

Greater Vancouver's drinking water treatment program

2001 ◽  
Vol 28 (S1) ◽  
pp. 36-48 ◽  
Author(s):  
A Mark D Ferguson ◽  
Douglas G Neden
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Treatment Program ◽  
Distribution System ◽  
Drinking Water Treatment ◽  
Geographical Information ◽  
Process Selection ◽  
Direct Filtration ◽  
Mountain Watersheds

The Greater Vancouver Regional District (GVRD) supplies water to 1.9 million people from three coastal mountain watersheds. Water quality concerns identified include waterborne disease risks associated with Giardia and Cryptosporidium, episodes of elevated turbidity, bacterial regrowth in the distribution system, and corrosive water. To address these concerns, the GVRD has initiated a $300 million capital program to upgrade its treatment capabilities that includes two 1200 ML·d–1 ozone and corrosion control facilities, a 1000 ML·d–1 filtration plant, and an ongoing program of rechlorination stations and distribution system improvements. This paper provides an overview of the GVRD's drinking water treatment program and related initiatives. These include the decision-making process related to using ozone without filtration, the process selection and selected project delivery method for the Seymour filtration plant, and, lastly, the ongoing secondary disinfection program which includes unidirectional flushing, reservoir exercising, environmental management, and remote data monitoring and data evaluation using a geographical information system application.Key words: water quality, protozoa, ozone, direct filtration, rechlorination, remote monitoring, GIS.

scholarly journals Integration of remote sensing, RUSLE and GIS to model potential soil loss and sediment yield (SY)

2013 ◽  
Vol 10 (4) ◽  
pp. 4567-4596 ◽  
Author(s):  
H. Kamaludin ◽  
T. Lihan ◽  
Z. Ali Rahman ◽  
M. A. Mustapha ◽  
W. M. R. Idris ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
River Water ◽  
Sediment Yield ◽  
Soil Loss ◽  
Satellite Images ◽  
River Mouth ◽  
Geographical Information ◽  
Rainfall Erosivity ◽  
Potential Soil Loss

Abstract. Land use activities within a basin serve as one of the contributing factors which cause deterioration of river water quality through its potential effect on erosion. Sediment yield in the form of suspended solid in the river water body which is transported to the coastal area occurs as a sign of lowering of the water quality. Hence, the aim of this study was to determine potential soil loss using the Revised Universal Soil Loss Equation (RUSLE) model and the sediment yield, in the Geographical Information Systems (GIS) environment within selected sub-catchments of Pahang River Basin. RUSLE was used to estimate potential soil losses and sediment yield by utilizing information on rainfall erosivity (R) using interpolation of rainfall data, soil erodibility (K) using field measurement and soil map, vegetation cover (C) using satellite images, topography (LS) using DEM and conservation practices (P) using satellite images. The results indicated that the rate of potential soil loss in these sub-catchments ranged from very low to extremely high. The area covered by very low to low potential soil loss was about 99%, whereas moderate to extremely high soil loss potential covered only about 1% of the study area. Sediment yield represented only 1% of the potential soil loss. The sediment yield (SY) value in Pahang River turned out to be higher closer to the river mouth because of the topographic character, climate, vegetation type and density, and land use within the drainage basin.

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