scholarly journals An integrated simulation method for flash-flood risk assessment: 2. Effects of changes in land-use under a historical perspective

2002 ◽  
Vol 6 (2) ◽  
pp. 285-294 ◽  
Author(s):  
R. Rosso ◽  
M.C. Rulli
Keyword(s):  
Risk Assessment ◽  
Land Use ◽  
Quantitative Methods ◽  
Historical Data ◽  
Land Use Changes ◽  
Flood Frequency ◽  
Distributed Model ◽  
Agricultural Practice ◽  
Simulation Approach ◽  
The Impact

Abstract. The influence of land use changes on flood occurrence and severity in the Bisagno River (Thyrrenian Liguria, N.W. Italy is investigated using a Monte Carlo simulation approach (Rulli and Rosso, 2002). High resolution land-use maps for the area were reconstructed and scenario simulations were made for a pre-industrial (1878), an intermediate (1930) and a current (1980) year. Land-use effects were explored to assess the consequences of distributed changes in land use due to agricultural practice and urbanisation. Hydraulic conveyance effects were considered, to assess the consequences of channel modifications associated with engineering works in the lower Bisagno River network. Flood frequency analyses of the annual flood series, retrieved from the simulations, were used to examine the effect of land-use change and river conveyance on flood regime. The impact of these effects proved to be negligible in the upper Bisagno River, moderate in the downstream river and severe in the small tributaries in the lower Bisagno valley that drain densely populated urban areas. The simulation approach is shown to be capable of incorporating historical data on landscape and river patterns into quantitative methods for risk assessment. Keywords: flood, simulation, distributed model, land-use changes, channel modifications, historical data

scholarly journals A non-stationary model for reconstruction of historical annual runoff on tropical catchments under increasing urbanization (Yaoundé, Cameroon)

2019 ◽  
Author(s):  
Camille Jourdan ◽  
Valérie Borrell-Estupina ◽  
David Sebag ◽  
Jean-Jacques Braun ◽  
Jean-Pierre Bedimo Bedimo ◽  
...  
Keyword(s):  
Land Use ◽  
Data Acquisition ◽  
Forest Cover ◽  
Land Use Changes ◽  
Annual Runoff ◽  
Distributed Model ◽  
Annual Rainfall ◽  
Runoff Coefficient ◽  
Experimental Modelling ◽  
The Impact

Abstract. Inter-tropical regions are nowadays faced to major land-use changes in data-sparse context leading to difficulties to assess hydrological signatures and their evolution. This work is part of the theme Panta Rhei of the IAHS, and aims to develop a combined approach of data acquisition and a new semi-distributed model taking into account land-use changes to reconstruct and predict annual runoff on an urban catchment. Applications were conducted on the Mefou catchment at Nsimalen (421 km2; Yaoundé, Cameroon) under rapid increase in urbanization since 1960. The data acquisition step combines an historical data processing and a short-term spatially-dense dedicated instrumentation (2017–2018), leading to 12 donor catchments, 6 from historical studies and 6 from the instrumentation presenting various topographic, soil and land-use characteristics. We developed an annual rainfall-runoff model based on mathematical relationships similar to the SCS model. The model needs the definition of a hydrological index I which is time variable and enables to take into account land-use changes and non-stationary relationships between rainfall and runoff. The index I is an empirical indicator defined as a combination of several components such as topography, soil, and land-use. The rules for the construction of I are obtained from data analysis on donor catchments. Then, the model was calibrated on donor catchments. Finally, two applications were conducted on eight target catchments composing the Mefou in order: (i) to study the spatial hydrological functioning and calculate the water balance during the short instrumentation period; (ii) to reconstruct the hydrograph at the Mefou and to simulate the impact of future scenarios of land-use and urbanization. Results show that that the Mfoundi catchment, integrating the three more urbanized sub-catchments, contributes near to 40 % of the Mefou despite covering only 23 % of the basin. The most urbanized sub-catchments present annual runoff coefficient about 0.86 against 0.24 for the most natural sub-catchments. The second result is the reconstruction of historical annual runoff from 1930–2017 with r2 = 0.68, RMSE = 99 mm and a mean absolute normalized error Ē = 14.5 % over the 29 observed years. The reconstruction of the annual runoff at Nsimalen confirms the moderate impact of urbanization on annual runoff before 1980. However, a decrease of about 50 % of the forest cover and an increase from 10 % to 35 % of the urban area between 1980 and 2017 are associated with an increase of 53 % of annual runoff coefficient for the Mefou at Nsimalen (0.44 against 0.29). Application for a fictive plausible scenario of urbanization in 2030 leads to an increase of more than 85 % of the annual runoff in comparison of the values observed in 1980. The coupled experimental-modelling approach proposed herein opens promising perspectives regarding the evaluation of the annual runoff in catchments under changes.

scholarly journals Application of the Frier Distributed Model for Estimating the Impact of Land use Changes on the Water Balance in Selected Basins in Slovakia

2009 ◽  
Vol 57 (4) ◽  
pp. 213-225 ◽  
Author(s):  
Oliver Horvát ◽  
Kamila Hlavčová ◽  
Silvia Kohnová ◽  
Michal Danko
Keyword(s):  
Land Use ◽  
Water Balance ◽  
Land Use Changes ◽  
Hydrological Regime ◽  
Distributed Model ◽  
Model Parameters ◽  
Hydrologic Processes ◽  
Rainfall Runoff Model ◽  
Using Data ◽  
The Impact

Application of the Frier Distributed Model for Estimating the Impact of Land use Changes on the Water Balance in Selected Basins in SlovakiaIn this study, the FRIER rainfall-runoff model with distributed parameters was developed to assess changes in runoff and water balance due to changes in land use and climate. The water balance was calculated at 3 levels: on the surface and in unsaturated and saturated zones. Six basins from the central and eastern parts of Slovakia were selected on the basis of their similar size, but different topography, land use, soil texture and climate: the upper Hornád, the upper Hron, the Poprad, the Rimava, the Slaná and the Torysa River basins. Model parameters were estimated using data from the period from June 1998 to May 2000 in daily time steps. The differences and similarities of the hydrologic processes in individual basins were investigated during the calibration period. Several scenarios of changes in land use and two simple scenarios of changes in climate were developed to estimate the impact of these changes on water balance and runoff. The changes in the hydrological regime were compared and discussed.

scholarly journals A Model-Based Tool for Assessing the Impact of Land Use Change Scenarios on Flood Risk in Small-Scale River Systems—Part 1: Pre-Processing of Scenario Based Flood Characteristics for the Current State of Land Use

Hydrology ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 102
Author(s):  
Frauke Kachholz ◽  
Jens Tränckner
Keyword(s):  
Land Use ◽  
River Flow ◽  
Land Use Changes ◽  
Small Rivers ◽  
Small Scale ◽  
Model Parameters ◽  
Ungauged Catchments ◽  
Model Based ◽  
Current State ◽  
The Impact

Land use changes influence the water balance and often increase surface runoff. The resulting impacts on river flow, water level, and flood should be identified beforehand in the phase of spatial planning. In two consecutive papers, we develop a model-based decision support system for quantifying the hydrological and stream hydraulic impacts of land use changes. Part 1 presents the semi-automatic set-up of physically based hydrological and hydraulic models on the basis of geodata analysis for the current state. Appropriate hydrological model parameters for ungauged catchments are derived by a transfer from a calibrated model. In the regarded lowland river basins, parameters of surface and groundwater inflow turned out to be particularly important. While the calibration delivers very good to good model results for flow (Evol =2.4%, R = 0.84, NSE = 0.84), the model performance is good to satisfactory (Evol = −9.6%, R = 0.88, NSE = 0.59) in a different river system parametrized with the transfer procedure. After transferring the concept to a larger area with various small rivers, the current state is analyzed by running simulations based on statistical rainfall scenarios. Results include watercourse section-specific capacities and excess volumes in case of flooding. The developed approach can relatively quickly generate physically reliable and spatially high-resolution results. Part 2 builds on the data generated in part 1 and presents the subsequent approach to assess hydrologic/hydrodynamic impacts of potential land use changes.

scholarly journals Rural-Spatial Restructuring Promoted by Land-Use Transitions: A Case Study of Zhulin Town in Central China

Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 234
Author(s):  
Dong Han ◽  
Jiajun Qiao ◽  
Qiankun Zhu
Keyword(s):  
Land Use ◽  
Rural Development ◽  
Structural Changes ◽  
Land Use Changes ◽  
Central China ◽  
Rural Space ◽  
Spatial Restructuring ◽  
Local Actors ◽  
The Impact

Rural-spatial restructuring involves the spatial mapping of the current rural development process. The transformation of land-use morphologies, directly or indirectly, affects the practice of rural restructuring. Analyzing this process in terms of the dominant morphology and recessive morphology is helpful for better grasping the overall picture of rural-spatial restructuring. Accordingly, this paper took Zhulin Town in Central China as a case study area. We propose a method for studying rural-spatial restructuring based on changes in the dominant and recessive morphologies of land use. This process was realized by analyzing the distribution and functional suitability of ecological-production-living (EPL) spaces based on land-use types, data on land-use changes obtained over a 30-year observation period, and in-depth research. We found that examining rural-spatial restructuring by matching the distribution of EPL spaces with their functional suitability can help to avoid the misjudgment of the restructuring mode caused by the consideration of the distribution and structural changes in quantity, facilitating greater understanding of the process of rural-spatial restructuring. Although the distribution and quantitative structure of Zhulin’s EPL spaces have changed to differing degrees, ecological- and agricultural-production spaces still predominate, and their functional suitability has gradually increased. The spatial distribution and functional suitability of Zhulin are generally well matched, with 62.5% of the matched types being high-quality growth, and the positive effect of Zhulin’s spatial restructuring over the past 30 years has been significant. We found that combining changes in EPL spatial area and quantity as well as changes in functional suitability is helpful in better understanding the impact of the national macro-policy shift regarding rural development. Sustaining the positive spatial restructuring of rural space requires the timely adjustment of local actors in accordance with the needs of macroeconomic and social development, and a good rural-governance model is essential.

scholarly journals Impact of Land Use Change on Water Conservation: A Case Study of Zhangjiakou in Yongding River

2020 ◽  
Vol 13 (1) ◽  
pp. 22
Author(s):  
Tianshi Pan ◽  
Lijun Zuo ◽  
Zengxiang Zhang ◽  
Xiaoli Zhao ◽  
Feifei Sun ◽  
...  
Keyword(s):  
Land Use ◽  
Sustainable Development ◽  
Water Conservation ◽  
Land Use Changes ◽  
Water Yield ◽  
Special Focus ◽  
Hydrological Process ◽  
Significant Difference ◽  
The Impact ◽  
Yongding River

The implementation of ecological projects can largely change regional land use patterns, in turn altering the local hydrological process. Articulating these changes and their effects on ecosystem services, such as water conservation, is critical to understanding the impacts of land use activities and in directing future land planning toward regional sustainable development. Taking Zhangjiakou City of the Yongding River as the study area—a region with implementation of various ecological projects—the impact of land use changes on various hydrological components and water conservation capacity from 2000 to 2015 was simulated based on a soil and water assessment tool model (SWAT). An empirical regression model based on partial least squares was established to explore the contribution of different land use changes on water conservation. With special focus on the forest having the most complex effects on the hydrological process, the impacts of forest type and age on the water conservation capacity are discussed on different scales. Results show that between 2000 and 2015, the area of forest, grassland and cultivated land decreased by 0.05%, 0.98% and 1.64%, respectively, which reduces the regional evapotranspiration (0.48%) and soil water content (0.72%). The increase in settlement area (42.23%) is the main reason for the increase in water yield (14.52%). Most land use covered by vegetation has strong water conservation capacity, and the water conservation capacity of the forest is particularly outstanding. Farmland and settlements tend to have a negative effect on water conservation. The water conservation capacity of forest at all scales decreased significantly with the growth of forest (p < 0.05), while the water conservation capacity of different tree species had no significant difference. For the study area, increasing the forest area will be an effective way to improve the water conservation function, planting evergreen conifers can rapidly improve the regional water conservation capacity, while planting deciduous conifers is of great benefit to long-term sustainable development.

scholarly journals Can land use changes alter carbon, nitrogen and major ion transport in subtropical brazilian streams?

2007 ◽  
Vol 64 (4) ◽  
pp. 317-324 ◽  
Author(s):  
Daniela Mariano Lopes da Silva ◽  
Jean Pierre Henry Balbaud Ometto ◽  
Gré de Araújo Lobo ◽  
Walter de Paula Lima ◽  
Marcos Augusto Scaranello ◽  
...  
Keyword(s):  
Land Use ◽  
Sugar Cane ◽  
Dissolved Inorganic Carbon ◽  
Comprehensive Evaluation ◽  
Land Use Changes ◽  
Agricultural Practices ◽  
Major Ion ◽  
Se Brazil ◽  
Tropical Watersheds ◽  
The Impact

Several studies in tropical watersheds have evaluated the impact of urbanization and agricultural practices on water quality. In Brazil, savannas (known regionally as Cerrados) represent 23% of the country's surface, representing an important share to the national primary growth product, especially due to intense agriculture. The purpose of this study is to present a comprehensive evaluation, on a yearly basis, of carbon, nitrogen and major ion fluxes in streams crossing areas under different land use (natural vegetation, sugar cane and eucalyptus) in a savanna region of SE Brazil. Eucalyptus and sugar cane alter the transport of the investigated elements in small watersheds. The highest concentration of all parameters (abiotic parameters, ions, dissolved organic carbon DOC - and dissolved inorganic carbon - DIC) were found in Sugar Cane Watersheds (SCW). The observed concentrations of major cations in Eucalyptus Watersheds (EW) (Mg, Ca, K, Na), as well as DIN and DOC, were found frequently to be intermediate values between those of Savanna Watersheds (SW) and SCW, suggesting a moderate impact of eucalyptus plantations on the streamwater. Same trends were found in relation to ion and nutrient fluxes, where the higher values corresponded to SCW. It is suggested that sugar cane plantations might be playing an important role in altering the chemistry of water bodies.

scholarly journals Strong increases in flood frequency and discharge of the River Meuse over the late Holocene: impacts of long-term anthropogenic land use change and climate variability

2008 ◽  
Vol 12 (1) ◽  
pp. 159-175 ◽  
Author(s):  
P. J. Ward ◽  
H. Renssen ◽  
J. C. J. H. Aerts ◽  
R. T. van Balen ◽  
J. Vandenberghe
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Climate Model ◽  
Land Use Changes ◽  
Winter Precipitation ◽  
Flood Frequency ◽  
High Flow ◽  
Recurrence Time ◽  
Strong Increase ◽  
Historical Sources

Abstract. In recent years the frequency of high-flow events on the Meuse (northwest Europe) has been relatively great, and flooding has become a major research theme. To date, research has focused on observed discharge records of the last century and simulations of the coming century. However, it is difficult to delineate changes caused by human activities (land use change and greenhouse gas emissions) and natural fluctuations on these timescales. To address this problem we coupled a climate model (ECBilt-CLIO-VECODE) and a hydrological model (STREAM) to simulate daily Meuse discharge in two time-slices: 4000–3000 BP (natural situation), and 1000–2000 AD (includes anthropogenic influence). For 4000–3000 BP the basin is assumed to be almost fully forested; for 1000–2000 AD we reconstructed land use based on historical sources. For 1000–2000 AD the simulated mean annual discharge (260.9 m3 s−1) is significantly higher than for 4000–3000 BP (244.8 m3 s−1), and the frequency of large high-flow events (discharge >3000 m3 s−1) is higher (recurrence time decreases from 77 to 65 years). On a millennial timescale almost all of this increase can be ascribed to land use changes (especially deforestation); the effects of climatic change are insignificant. For the 20th Century, the simulated mean discharge (270.0 m3 s−1) is higher than in any other century studied, and is ca. 2.5% higher than in the 19th Century (despite an increase in evapotranspiration). Furthermore, the recurrence time of large high-flow events is almost twice as short as under natural conditions (recurrence time decreases from 77 to 40 years). On this timescale climate change (strong increase in annual and winter precipitation) overwhelmed land use change as the dominant forcing mechanism.

scholarly journals Evaluating and Predicting the Effects of Land Use Changes on Hydrology in Wami River Basin, Tanzania

Hydrology ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 17 ◽  
Author(s):  
Sekela Twisa ◽  
Shija Kazumba ◽  
Mathew Kurian ◽  
Manfred F. Buchroithner
Keyword(s):  
Land Use ◽  
Water Resources ◽  
Assessment Tool ◽  
Swat Model ◽  
Land Use Changes ◽  
Management Strategies ◽  
River System ◽  
Least Squares Regression ◽  
Natural Forests ◽  
The Impact

Understanding the variation in the hydrological response of a basin associated with land use changes is essential for developing management strategies for water resources. The impact of hydrological changes caused by expected land use changes may be severe for the Wami river system, given its role as a crucial area for water, providing food and livelihoods. The objective of this study is to examine the influence of land use changes on various elements of the hydrological processes of the basin. Hybrid classification, which includes unsupervised and supervised classification techniques, is used to process the images (2000 and 2016), while CA–Markov chain analysis is used to forecast and simulate the 2032 land use state. In the current study, a combined approach—including a Soil and Water Assessment Tool (SWAT) model and Partial Least Squares Regression (PLSR)—is used to explore the influences of individual land use classes on fluctuations in the hydrological components. From the study, it is evident that land use has changed across the basin since 2000 (which is expected to continue in 2032), as well as that the hydrological effects caused by land use changes were observed. It has been found that the major land use changes that affected hydrology components in the basin were expansion of cultivation land, built-up area and grassland, and decline in natural forests and woodland during the study period. These findings provide baseline information for decision-makers and stakeholders concerning land and water resources for better planning and management decisions in the basin resources’ use.

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