scholarly journals Mitigating Drought Conditions under Climate and Land Use Changes by Applying Hedging Rules for the Multi-Reservoir System

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3095
Author(s):  
Zejun Li ◽  
Bensheng Huang ◽  
Zhifeng Yang ◽  
Jing Qiu ◽  
Bikui Zhao ◽  
...  
Keyword(s):  
Land Use ◽  
Environmental Changes ◽  
Land Use Changes ◽  
Hydrologic Model ◽  
Future Climate ◽  
Severe Drought ◽  
Reservoir System ◽  
Operating Rules ◽  
Drought Conditions ◽  
Hedging Rules

Climate and land use changes have substantially affected hydrologic cycles and increased the risk of drought. Reservoirs are one of the important means to provide resilience against hydrologic variability and achieve sustainable water management. Therefore, adaptive reservoir operating rules are needed to mitigate their adverse effects. In this study, the Hanjiang River Basin in southeast China was selected as the study area. Future climate and land use projections were produced by the Delta method and CA-Markov model, respectively. Future climate forcings and land use patterns were then incorporated into a distributed hydrologic model to evaluate river flow regime shifts. Results revealed that climate and land use changes may lead to severe drought conditions in the future. Lower flows are shown to be more sensitive to environmental changes and a decline of monthly flows could reach up to nearly 30% in the dry season. To address the threat of increasing drought uncertainties in the water supply system, the aggregation-decomposition method incorporated with hedging rules was applied to guide the multi-reservoir operation. Parameters of optimal hedging rules were obtained by a multi-objective optimization algorithm. The performance of hedging rules was evaluated by comparison to standard operating policies and conventional operating rules with respect to reliability, resiliency, vulnerability, and sustainability indices. Results showed that the multi-reservoir system guided by hedging rules can be more adaptive to the environmental changes.

Application of WetSpa model for assessing land use impacts on floods in the Margecany–Hornad watershed, Slovakia

2006 ◽  
Vol 53 (10) ◽  
pp. 37-45 ◽  
Author(s):  
A. Bahremand ◽  
F. De Smedt ◽  
J. Corluy ◽  
Y.B. Liu ◽  
J. Poórová ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Hydrologic Model ◽  
Land Use Impacts ◽  
M Cell ◽  
Time To Peak ◽  
Wetspa Model ◽  
Spatially Distributed ◽  
The Impact ◽  
Good Agreement

The spatially distributed hydrologic model WetSpa combines elevation, soil and land use data within GIS, to predict flood hydrographs and spatial distribution of hydrologic characteristics in a watershed. The model is applied to the Margecany–Hornad river basin (1,131 km2) in Slovakia. Daily hydrometeorological data from 1991–2000, including precipitation data from nine stations, temperature data from four stations and evaporation data measured at one station are used as input to the model. Three base maps, i.e. DEM, land use and soil type are prepared in GIS form, using 100 × 100 m cell size. Results of the simulations show good agreement between calculated and measured hydrographs. The model predicts the daily/hourly hydrographs with 75–80% accuracy according to the Nash–Sutcliff criteria. For assessing the impact of land use changes on floods, the calibrated model is applied for a reforestation scenario, which considers a 50% increase of forest areas. The model results show that the reforestation scenario decreases the peak discharge by 12%. Investigation of peak discharges from the whole simulation period, shows that the scenario results are reduced by 18% on average, while for small discharges the reduction is even about 34%. The time to peak of the simulated hydrograph of the reforestation scenario is 20 hours longer than for the present land use.

Land Planning, Agro-forest Systems, and Implications for Ecosystem Services: Insights from Northern Italy

2021 ◽  
Author(s):  
Antonio Tomao ◽  
Barbara Ermini ◽  
Marcela Prokopov ◽  
Adriano Conte
Keyword(s):  
Land Use ◽  
Environmental Changes ◽  
Land Use Changes ◽  
Value Added ◽  
Temporal Analysis ◽  
Land Use Land Cover ◽  
Development Patterns ◽  
The North ◽  
Multi Temporal ◽  
Potential Impact

Negative environmental changes generally addressed as ‘syndromes’ are evaluated in the context of Soil Degradation (SD) and interpreted by using a ‘Land-Use/Land Cover Changes’ (LULCCs) framework in order to disentangle ‘past trajectories’, ‘present patterns’, and ‘future changes’. This approach allows to discuss the potential impact on SD processes and it represents an informed basis for identifying measurable outcomes of SD. This study focuses on the case of Emilia Romagna, a region located in the North of Italy with high-value added agricultural productions. A multi-temporal analysis of land-use changes between 1954 and 2008 has been proposed, discussing the evolution of associated SD syndromes in Emilia Romagna. The contributing information have been used as a baseline for Sustainable Land Management (SLM) strategies. This framework of analysis provides useful tools to investigate and to monitor the effects of SD in the Mediterranean basin where several regions underwent common development patterns yelding global pathological symptoms of environmental degradation.

Global Natural Hazard and Disaster Vulnerability Management

2018 ◽  
pp. 83-104
Author(s):  
Nkemdilim Maureen Ekpeni ◽  
Amidu Owolabi Ayeni
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Natural Resources ◽  
Natural Hazard ◽  
Environmental Changes ◽  
Land Use Changes ◽  
Physical Environments ◽  
Vulnerability Management ◽  
Research Findings ◽  
Two Sides

This chapter examines both concept of global hazard and disaster and its management in the lights of its vulnerability. It categorized the different types of hazards and disasters and their components. From the research findings, it is observed that hazards and disaster are two sides of a coin. They occur at the interface between human systems and natural events in our physical environments. This chapter highlights that the major environmental changes driving hazards and vulnerability to disasters are climate change, land-use changes, and degradation of natural resources. After presenting a typology of disasters and their magnitude globally, management of disaster has transited from just being a “response and relief”-centric approach to a mitigation and preparedness approach.

scholarly journals The influence of deforestation and anthropogenic activities on runoff generation

2017 ◽  
Vol 63 (No. 6) ◽  
pp. 245-253 ◽  
Author(s):  
Khaleghi Mohammad Reza
Keyword(s):  
Land Use ◽  
Forest Cover ◽  
Anthropogenic Activities ◽  
Land Use Changes ◽  
Hydrologic Model ◽  
Geographical Information ◽  
Runoff Generation ◽  
Mazandaran Province ◽  
Gis And Remote Sensing ◽  
Flood Peak

In recent decades, due to rapid human population increases and in its results, destructive effects of anthropogenic activities on natural resources have become a great challenge. Land use and vegetation are important factors in soil erosion and runoff generation. This study was performed to assess the effects of different amounts of forest cover on the control of runoff and soil loss in the Talar basin, which is located in Mazandaran province, using a runoffrainfall model, geographical information system (GIS) and remote sensing (RS) to determine the hydrologic effects of deforestation on the Talar watershed (north of Iran). A runoff-rainfall model has been presented using GIS (HECGeoHMS) and hydrologic model (HEC-HMS). Land use changes (deforestation) and anthropogenic activities (roads and impervious surfaces development) were evaluated using RS techniques and satellite images. We used the Soil Conservation Service and Curve Number methods for hydrograph simulation and runoff estimation, respectively. First, a model was performed and optimized. Afterward, the optimized model was evaluated by other six events of floods (model validation). According to the obtained results, the runoff generation potential has been increased in the Talar watershed due to deforestation during the last forty years. Land use changes cause an increase in runoff volume and flood peak discharge.

Changes in hydrological behaviour: case studies of the Unica and Rižana karst springs, Slovenia

2020 ◽  
Author(s):  
Natasa Ravbar ◽  
Gregor Kovačič ◽  
Metka Petrič
Keyword(s):  
Land Use ◽  
Large Scale ◽  
Environmental Changes ◽  
Hydrological Cycle ◽  
Land Use Changes ◽  
Precipitation Amount ◽  
Flood Pulse ◽  
Karst Springs ◽  
The Impact ◽  
Gauging Station

<p>Environmental changes, such as alterations in precipitation and evapotranspiration regimes, changes in vegetation type, etc. are triggering direct impact on hydrological cycle through modified amounts and patterns of recharge conditions, as well as occurrence of more frequent and severe hydrometeorological events. Karst aquifers are particularly vulnerable to these effects due to highly dynamic hydrological processes. In this study, we were interested in studying the possibilities to observe changed hydrological behaviour of karst springs on a human timescale. Therefore, we focused on two examples in Slovenia, both regionally important for freshwater supply, agriculture and hydropower. The Unica spring mostly drains areas under moderate continental climate. Its catchment has been repeatedly and severely hit by natural disasters (e.g., ice break, bark beetle attack, windthrow) after 2014 causing large-scale forest disturbances. The catchment of Rižana spring, on the other hand, belongs to the moderate Submediterranean climate. There these types of disturbance did not occur in recent years (excluding some wildfires), but the catchment has been liable to substantial land use changes in the past six decades. For assessment of vegetation cover changes and large-scale disturbances in forests, historical digital orthophotos of the Surveying and Mapping Authority of the Republic of Slovenia since 1957 have been compared with the recent land use data provided by Ministry of Agriculture, Economy and Food and forest state database of Slovenian Forest Service. At the same time, hydrological data of the Unica (Hasberg gauging station) in the period 1962-2018 and Rižana springs (Kubed gauging station) in the period 1966-2018 and precipitation data from Postojna (period 1962-2018) and Podgrad (period 1966-2018) meteorological stations have been processed. Individual flood pulse events over the 57 years for Unica and 53 years for Rižana have been separated. For each flood pulse various information about precipitation amount and intensity, duration of discharge increase, its intensity and amplitude have been specified. We compared these findings with the calculated trends of meteorological and hydrological variables and also changes in land use. The impact of particular environmental change on discharge values of both springs has been evaluated, showing that both, climate and land-use changes, have considerable impact on hydrological regime of studied karst springs. In particular, altered duration of flood pulses increase, their amplitude and intensity have been observed, meaning that the most important issues of water availability that are crucial for water-dependant economic sectors are under threat.</p>

scholarly journals Traditional and Local Ecological Knowledge for Land Use Mapping

2015 ◽  
Vol 747 ◽  
pp. 306-309 ◽  
Author(s):  
Norizawati Mohd Ayob ◽  
Norhasimah Ismail ◽  
Tarmiji Masron
Keyword(s):  
Land Use ◽  
Cultural Values ◽  
Environmental Changes ◽  
Local Ecological Knowledge ◽  
Land Use Changes ◽  
Ecological Knowledge ◽  
Way Of Life ◽  
Global Environmental ◽  
History Of ◽  
Global Environmental Changes

Land use changes are a key driver in global environmental changes and had a significant impact on the climate at all scales. Various human activities that took place thousands of years ago have an impact on the earth's surface. Today, with the limited supply and high demand, land use crisis became a big issue for the most countries. Changes in land use are not actually only providing a history of the area, but it also describes the way of life of its local communities. In the interdisciplinary research for land use study, cultural values, knowledge and perceptions of knowledge has been recognized as a major factor in determining the adopted approach applied in land use management in that area. Therefore, this paper tries to evaluate the role and potential of the integration of TLEK and GIS in mapping the series of changes in land use.Keyword: Local knowledge, TLEK, land use mapping & conceptual framework

Differences in the responses of flow and nutrient load to isolated and coupled future climate and land use changes

2020 ◽  
Vol 256 ◽  
pp. 109918 ◽  
Author(s):  
Chuan Luo ◽  
Zhaofu Li ◽  
Hongyu Liu ◽  
Hengpeng Li ◽  
Rongrong Wan ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Future Climate ◽  
Nutrient Load

scholarly journals Si cycling in transition zones: a study of Si isotopes and biogenic silica accumulation in the Chesapeake Bay through the Holocene

2019 ◽  
Vol 146 (2) ◽  
pp. 145-170
Author(s):  
Carla K. M. Nantke ◽  
Patrick J. Frings ◽  
Johanna Stadmark ◽  
Markus Czymzik ◽  
Daniel J. Conley
Keyword(s):  
Land Use ◽  
Chesapeake Bay ◽  
Biogenic Silica ◽  
Environmental Changes ◽  
Land Use Changes ◽  
Sediment Cores ◽  
Global Scale ◽  
Silicon Isotope ◽  
Coastal Zones ◽  
Local Climate

AbstractSi fluxes from the continents to the ocean are a key element of the global Si cycle. Due to the ability of coastal ecosystems to process and retain Si, the ‘coastal filter’ has the potential to alter Si fluxes at a global scale. Coastal zones are diverse systems, sensitive to local environmental changes, where Si cycling is currently poorly understood. Here, we present the first palaeoenvironmental study of estuarine biogenic silica (BSi) fluxes and silicon isotope ratios in diatoms (δ30Sidiatom) using hand-picked diatom frustules in two sediment cores (CBdist and CBprox) from the Chesapeake Bay covering the last 12000 and 8000 years, respectively. Constrained by the well-understood Holocene evolution of the Chesapeake Bay, we interpret variations in Si cycling in the context of local climate, vegetation and land use changes. δ30Sidiatom varies between + 0.8 and + 1.7‰ in both sediment cores. A Si mass balance for the Chesapeake Bay suggests much higher rates of Si retention (~ 90%) within the system than seen in other coastal systems. BSi fluxes for both sediment cores co-vary with periods of sea level rise (between 9500 and 7500 a BP) and enhanced erosion due to deforestation (between 250 and 50 a BP). However, differences in δ30Sidiatom and BSi flux between the sites emphasize the importance of the seawater/freshwater mixing ratios and locally variable Si inputs from the catchment. Further, we interpret variations in δ30Sidiatom and the increase in BSi fluxes observed since European settlement (~ 250 a BP) to reflect a growing human influence on the Si cycle in the Chesapeake Bay. Thereby, land use change, especially deforestation, in the catchment is likely the major mechanism.

Influences of land use changes on the dynamics of water quantity and quality in the German lowland catchment of the Stör

2021 ◽  
Author(s):  
Chaogui Lei ◽  
Paul Wagner ◽  
Nicola Fohrer
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Arable Land ◽  
Hydrologic Model ◽  
Water Quantity ◽  
Water Yield ◽  
Near Surface ◽  
Daily Streamflow ◽  
Land Use Types ◽  
Water Quantity And Quality

<p>Understanding the impacts of land use changes (LUCC) on the dynamics of water quantity and quality is necessary to identify suitable mitigation measures that are needed for sustainable watershed management. Lowland catchments are characterized by a strong interaction of streamflow and near-surface groundwater that intensifies the risk of nutrient pollution. In this study, a hydrologic model (Soil and Water Assessment Tool, SWAT) and partial least squares regression (PLSR) were used to quantify the impacts of different land use types on the variations in actual evapotranspiration (ET), surface runoff (SQ), base flow (BF), and water yield (WYLD) as well as on sediment (SED), total phosphorus (TP), and total nitrogen (TN). To this end, the model was calibrated and validated with daily streamflow data (30 years) and daily sediment and nutrient data from measurement campaigns (3 years in total). Three model runs over thirty years were performed using the different land use maps of 1987, 2010, and 2019, respectively. Land use changes between those years were used to explain the modelled changes in water quantity and quality on the subbasin scale applying PLSR. SWAT achieved a good performance for streamflow (calibration: NSE=0.8, PBIAS=5.5%; validation: NSE=0.78, PBIAS=5.1%) and for TN (calibration: NSE=0.65, PBIAS= -11.3%; validation: NSE=0.87, PBIAS=2.7%) and an acceptable performance for sediment and TP (calibration: NSE=0.49-0.53, PBIAS=25.8% -29.7%; validation: 0.51-0.7, PBIAS= -23.9% - -8.7%) in Stör catchment. The variations in ET, SQ, BF, WYLD, SED, TP, and TN could be explained to an extent of 67%-88% by changes in the area, shape, dominance, and aggregation of individual land use types. They were largely correlated with the major LUCC in the study area i.e. a decrease of arable land, and a respective increase of pasture and settlement. The change in the percentage of arable land affected the dynamics of SED, TP, TN and BF, indicated by a Variable Influence on Projection (VIP) > 1.2 and largest absolute regression coefficients (RCs: 0.45-0.72 for SED, TP, TN; -0.84 for BF). The change in pasture area affected ET, SED, TP, and TN, as indicated by VIPs >1.  The change in settlement percentage had VIP up to 1.62 for SQ and was positively and significantly influenced it (RC: 1.28). PLSR helped to identify the key contributions from individual land use changes on water quantity and quality dynamics. These provide a quantitative basis for targeting most influential land use changes to mitigate impacts on water quality in the future.</p>

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