The effects of ENSO, climate change and human activities on the water level of Lake Toba, Indonesia: a critical literature review

AbstractThis research quantitatively and qualitatively analyzes the factors responsible for the water level variations in Lake Toba, North Sumatra Province, Indonesia. According to several studies carried out from 1993 to 2020, changes in the water level were associated with climate variability, climate change, and human activities. Furthermore, these studies stated that reduced rainfall during the rainy season due to the El Niño Southern Oscillation (ENSO) and the continuous increase in the maximum and average temperatures were some of the effects of climate change in the Lake Toba catchment area. Additionally, human interventions such as industrial activities, population growth, and damage to the surrounding environment of the Lake Toba watershed had significant impacts in terms of decreasing the water level. However, these studies were unable to determine the factor that had the most significant effect, although studies on other lakes worldwide have shown these factors are the main causes of fluctuations or decreases in water levels. A simulation study of Lake Toba's water balance showed the possibility of having a water surplus until the mid-twenty-first century. The input discharge was predicted to be greater than the output; therefore, Lake Toba could be optimized without affecting the future water level. However, the climate projections depicted a different situation, with scenarios predicting the possibility of extreme climate anomalies, demonstrating drier climatic conditions in the future. This review concludes that it is necessary to conduct an in-depth, comprehensive, and systematic study to identify the most dominant factor among the three that is causing the decrease in the Lake Toba water level and to describe the future projected water level.

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Climate corridors for strategic adaptation planning

International Journal of Climate Change Strategies and Management ◽

10.1108/ijccsm-12-2016-0183 ◽

2017 ◽

Vol 9 (6) ◽

pp. 811-828

Author(s):

Boris Orlowsky ◽

Pierluigi Calanca ◽

Irshad Ali ◽

Jawad Ali ◽

Agustin Elguera Hilares ◽

...

Keyword(s):

Climate Change ◽

Human Activities ◽

Low Cost ◽

Climatic Conditions ◽

Data Availability ◽

Adaptation Planning ◽

Climate Projections ◽

Development Projects ◽

Content Type ◽

Wide Range

Purpose Although the importance of climate change is generally acknowledged, its impacts are often not taken into account explicitly when planning development projects. This being due to limited resources, among others, this paper aims to propose a simple and low-cost approach to assess the viability of human activities under climate change. Design/methodology/approach Many human activities are feasible only within a narrow range of climatic conditions. Comparing such “climate corridors” with future climate projections provides an intuitive yet quantitative means for assessing needs for, and the viability of, adaptation activities under climate change. Findings The approach was tested within development projects in Pakistan, Peru and Tajikistan. The approach was shown to work well for forestry and agriculture, indicating positive/negative prospects for wheat in two districts in Pakistan, temperature constraints for maize in Peru and widening elevation ranges for walnut trees in Tajikistan. Practical implications Climate corridor analyses feed into the preparation of Local Adaptation Plans of Action in Pakistan. Originality/value The simplicity and robustness of climate corridor analysis allow for efficient analysis and communication of climate change impacts. It works when data availability is limited, but it can as well accommodate a wide range of complexities. It has proven to be an effective vehicle for mainstreaming climate change into adaptation planning.

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Prediction of Groundwater Level Variations in a Changing Climate: A Danish Case Study

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi10110792 ◽

2021 ◽

Vol 10 (11) ◽

pp. 792

Author(s):

Rebeca Quintero Gonzalez ◽

Jamal Jokar Arsanjani

Keyword(s):

Climate Change ◽

Machine Learning ◽

Water Level ◽

Water Table ◽

Water Levels ◽

Series Data ◽

Future Climate Change ◽

Support Vector ◽

Climate Change Scenarios ◽

The Future

Shallow groundwater is a key resource for human activities and ecosystems, and is susceptible to alterations caused by climate change, causing negative socio-economic and environmental impacts, and increasing the need to predict the evolution of the water table. The main objective of this study is to gain insights about future water level changes based on different climate change scenarios using machine learning algorithms, while addressing the following research questions: (a) how will the water table be affected by climate change in the future based on different socio-economic pathways (SSPs)?: (b) do machine learning models perform well enough in predicting changes of the groundwater in Denmark? If so, which ML model outperforms for forecasting these changes? Three ML algorithms were used in R: artificial neural networks (ANN), support vector machine (SVM) and random forest (RF). The ML models were trained with time-series data of groundwater levels taken at wells in the Hovedstaden region, for the period 1990–2018. Several independent variables were used to train the models, including different soil parameters, topographical features and climatic variables for the time period and region selected. Results show that the RF model outperformed the other two, resulting in a higher R-squared and lower mean absolute error (MAE). The future prediction maps for the different scenarios show little variation in the water table. Nevertheless, predictions show that it will rise slightly, mostly in the order of 0–0.25 m, especially during winter. The proposed approach in this study can be used to visualize areas where the water levels are expected to change, as well as to gain insights about how big the changes will be. The approaches and models developed with this paper could be replicated and applied to other study areas, allowing for the possibility to extend this model to a national level, improving the prevention and adaptation plans in Denmark and providing a more global overview of future water level predictions to more efficiently handle future climate change scenarios.

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Impact of climate change on hydro-meteorological drought over the Be River Basin, Viet Nam

Journal of Water and Climate Change ◽

10.2166/wcc.2021.137 ◽

2021 ◽

Author(s):

Dao Nguyen Khoi ◽

Truong Thao Sam ◽

Pham Thi Loi ◽

Bui Viet Hung ◽

Van Thinh Nguyen

Keyword(s):

Climate Change ◽

River Basin ◽

General Circulation ◽

Southern Oscillation ◽

Meteorological Drought ◽

Climate Projections ◽

Research Station ◽

Climate Change Scenarios ◽

Study Region ◽

Meteorological Droughts

Abstract In this paper, the responses of hydro-meteorological drought to changing climate in the Be River Basin located in Southern Vietnam are investigated. Climate change scenarios for the study area were statistically downscaled using the Long Ashton Research Station Weather Generator tool, which incorporates climate projections from Coupled Model Intercomparison Project 5 (CMIP5) based on an ensemble of five general circulation models (Can-ESM2, CNRM-CM5, HadGEM2-AO, IPSL-CM5A-LR, and MPI-ESM-MR) under two Representative Concentration Pathway (RCP) scenarios (RCP4.5 and RCP8.5). The Soil and Water Assessment Tool model was employed to simulate streamflow for the baseline time period and three consecutive future 20 year periods of 2030s (2021–2040), 2050s (2041–2060), and 2070s (2061–2080). Based on the simulation results, the Standardized Precipitation Index and Standardized Discharge Index were estimated to evaluate the features of hydro-meteorological droughts. The hydrological drought has 1-month lag time from the meteorological drought and the hydro-meteorological droughts have negative correlations with the El Niño Southern Oscillation and Pacific Decadal Oscillation. Under the climate changing impacts, the trends of drought severity will decrease in the future; while the trends of drought frequency will increase in the near future period (2030s), but decrease in the following future periods (2050 and 2070s). The findings of this study can provide useful information to the policy and decisionmakers for a better future planning and management of water resources in the study region.

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Intensification of future low-flow events in relation to projected changes in large-scale climate drivers due to climate change

10.5194/egusphere-egu21-15366 ◽

2021 ◽

Author(s):

Pallavi Goswami ◽

Arpita Mondal ◽

Christoph Rüdiger ◽

Tim J. Peterson

Keyword(s):

Climate Change ◽

Large Scale ◽

Linear Models ◽

Southern Oscillation ◽

Value Theory ◽

Extreme Value ◽

Low Flow ◽

Generalised Linear Models ◽

Southeast Australia ◽

The Future

Large-scale climate processes such as the El Nino Southern Oscillation (ENSO), Indian Ocean Dipole (IOD) and Southern Annular Mode (SAM) influence the hydro-climatology of Southeast Australia (SEA). In the present study, we show that low-flow events in many catchments in SEA are significantly influenced by variability in these climate drivers. Extreme value distributions and Generalised Linear Models (GLMs) are used here to model low-flow characteristics such as intensity, duration and frequency with respect to these climate drivers. Further, we study how the future projections of ENSO, IOD and SAM are likely to evolve under climate change by examining the projected values of their representative indices and how they will impact low-flow events in the region. It is found that the future dry phases of these climate drivers are likely to be more dry than those in the historic period. This in turn is expected to lead to intensification of low-flow events in the future, resulting in lower availability of fresh water during occurrences of the dry phases of these climate drivers. Thus, climate change in the future is expected to significantly influence future low-flow events in the region thereby making it even more crucial for water managers to adequately manage and ensure water availability. Keywords: low-flows, ENSO, IOD, SAM, Extreme Value Theory, Generalised Linear Models, Southeast Australia, CMIP5, RCP8.5.

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Lake water level response to drought in a lake-rich region explained by lake and landscape characteristics

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2019-0270 ◽

2020 ◽

Vol 77 (11) ◽

pp. 1836-1845

Author(s):

K. Martin Perales ◽

Catherine L. Hein ◽

Noah R. Lottig ◽

M. Jake Vander Zanden

Keyword(s):

Climate Change ◽

Water Level ◽

Lake Water ◽

Water Levels ◽

Water Level Fluctuations ◽

Lake Area ◽

Lake Water Level ◽

Landscape Characteristics ◽

Lake Ecology ◽

Coarse Woody Habitat

Climate change is altering hydrologic regimes, with implications for lake water levels. While lakes within lake districts experience the same climate, lakes may exhibit differential climate vulnerability regarding water level response to drought. We took advantage of a recent drought (∼2005–2010) and estimated changes in lake area, water level, and shoreline position on 47 lakes in northern Wisconsin using high-resolution orthoimagery and hypsographic curves. We developed a model predicting water level response to drought to identify characteristics of the most vulnerable lakes in the region, which indicated that low-conductivity seepage lakes found high in the landscape, with little surrounding wetland and highly permeable soils, showed the greatest water level declines. To explore potential changes in the littoral zone, we estimated coarse woody habitat (CWH) loss during the drought and found that drainage lakes lost 0.8% CWH while seepage lakes were disproportionately impacted, with a mean loss of 40% CWH. Characterizing how lakes and lake districts respond to drought will further our understanding of how climate change may alter lake ecology via water level fluctuations.

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A Simplistic Approach for Assessing Hydroclimatic Vulnerability of Lakes and Reservoirs with Regulated Superficial Outflow

Hydrology ◽

10.3390/hydrology6030061 ◽

2019 ◽

Vol 6 (3) ◽

pp. 61 ◽

Cited By ~ 1

Author(s):

Kleoniki Demertzi ◽

Dimitris Papadimos ◽

Vassilis Aschonitis ◽

Dimitris Papamichail

Keyword(s):

Climate Change ◽

General Circulation ◽

Drainage Basin ◽

Management Strategies ◽

General Circulation Models ◽

Climatic Conditions ◽

Modified Model ◽

Natural Lakes ◽

The Future ◽

The Impact

This study proposes a simplistic model for assessing the hydroclimatic vulnerability of lakes/reservoirs (LRs) that preserve their steady-state conditions based on regulated superficial discharge (Qd) out of the LR drainage basin. The model is a modification of the Bracht-Flyr et al. method that was initially proposed for natural lakes in closed basins with no superficial discharge outside the basin (Qd = 0) and under water-limited environmental conditions {mean annual ratio of potential/reference evapotranspiration (ETo) versus rainfall (P) greater than 1}. In the proposed modified approach, an additional Qd function is included. The modified model is applied using as a case study the Oreastiada Lake, which is located inside the Kastoria basin in Greece. Six years of observed data of P, ETo, Qd, and lake topography were used to calibrate the modified model based on the current conditions. The calibrated model was also used to assess the future lake conditions based on the future climatic projections (mean conditions of 2061-2080) derived by 19 general circulation models (GCMs) for three cases of climate change (three cases of Representative Concentration Pathways: RCP2.6, RCP4.5 and RCP8.5). The modified method can be used as a diagnostic tool in water-limited environments for analyzing the superficial discharge changes of LRs under different climatic conditions and to support the design of new management strategies for mitigating the impact of climate change on (a) flooding conditions, (b) hydroelectric production, (c) irrigation/industrial/domestic use and (d) minimum ecological flows to downstream rivers.

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Selection of Bias Correction Methods to Assess the Impact of Climate Change on Flood Frequency Curves

Water ◽

10.3390/w11112266 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2266 ◽

Cited By ~ 4

Author(s):

Enrique Soriano ◽

Luis Mediero ◽

Carlos Garijo

Keyword(s):

Climate Change ◽

Bias Correction ◽

Climate Models ◽

Climate Model ◽

Control Period ◽

Flood Frequency ◽

Climate Projections ◽

The Future ◽

Flood Quantiles ◽

The Impact

Climate projections provided by EURO-CORDEX predict changes in annual maximum series of daily rainfall in the future in some areas of Spain because of climate change. Precipitation and temperature projections supplied by climate models do not usually fit exactly the statistical properties of the observed time series in the control period. Bias correction methods are used to reduce such errors. This paper seeks to find the most adequate bias correction techniques for temperature and precipitation projections that minimizes the errors between observations and climate model simulations in the control period. Errors in flood quantiles are considered to identify the best bias correction techniques, as flood quantiles are used for hydraulic infrastructure design and safety assessment. In addition, this study aims to understand how the expected changes in precipitation extremes and temperature will affect the catchment response in flood events in the future. Hydrological modelling is required to characterize rainfall-runoff processes adequately in a changing climate, in order to estimate flood changes expected in the future. Four catchments located in the central-western part of Spain have been selected as case studies. The HBV hydrological model has been calibrated in the four catchments by using the observed precipitation, temperature and streamflow data available on a daily scale. Rainfall has been identified as the most significant input to the model, in terms of its influence on flood response. The quantile mapping polynomial correction has been found to be the best bias correction method for precipitation. A general reduction in flood quantiles is expected in the future, smoothing the increases identified in precipitation quantiles by the reduction of soil moisture content in catchments, due to the expected increase in temperature and decrease in mean annual precipitations.

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Late Quaternary Water-Level Variations and Vegetation History at Crooked Pond, Southeastern Massachusetts

Quaternary Research ◽

10.1006/qres.2001.2273 ◽

2001 ◽

Vol 56 (3) ◽

pp. 401-410 ◽

Cited By ~ 77

Author(s):

Bryan Shuman ◽

Jennifer Bravo ◽

Jonathan Kaye ◽

Jason A. Lynch ◽

Paige Newby ◽

...

Keyword(s):

New England ◽

Water Level ◽

Vegetation History ◽

Late Quaternary ◽

Sediment Cores ◽

Climatic Conditions ◽

Water Levels ◽

Eastern Canada ◽

Southern New England ◽

Dramatic Rise

AbstractSediment cores collected along a transect in Crooked Pond, southeastern Massachusetts, provide evidence of water-level changes between 15,000 cal yr B.P. and present. The extent of fine-grained, detrital, organic accumulation in the basin, inferred from sediment and pollen stratigraphies, varied over time and indicates low water levels between 11,200 and 8000 cal yr B.P. and from ca. 5300 to 3200 cal yr B.P. This history is consistent with the paleohydrology records from nearby Makepeace Cedar Swamp and other sites from New England and eastern Canada and with temporal patterns of regional changes in effective soil moisture inferred from pollen data. The similarities among these records indicate that (1) regional conditions were drier than today when white pine (Pinus strobus) grew abundantly in southern New England (11,200 to 9500 cal yr B.P.); (2) higher moisture levels existed between 8000 and 5500 cal yr B.P., possibly caused by increased meridonal circulation as the influence of the Laurentide ice sheet waned; and (3) drier conditions possibly contributed to the regional decline in hemlock (Tsuga) abundances at 5300 cal yr B.P. Although sea-level rise may have been an influence, moist climatic conditions during the late Holocene were the primary reason for a dramatic rise in water-table elevations.

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A New Framework to Evaluate Urban Design Using Urban Microclimatic Modelling in Future Climatic Conditions

10.20944/preprints201802.0109.v1 ◽

2018 ◽

Author(s):

Dasaraden Mauree ◽

Silvia Coccolo ◽

Dasun Perera ◽

Vahid Nik ◽

Jean-Louis Scartezzini ◽

...

Keyword(s):

Climate Change ◽

Energy Consumption ◽

Urban Design ◽

Urban Areas ◽

Energy System ◽

Climatic Conditions ◽

Local Climate ◽

Heating And Cooling ◽

The Future ◽

The Impact

Building more energy efficient and sustainable urban areas that will both mitigate the effect of climate change and adapt for the future climate, requires the development new tools and methods that can help urban planners, architect and communities achieve this goal. In the current study, we designed a workflow that links different methodologies developed separately, to derive the energy consumption of a university school campus for the future. Three different scenarios for typical future years (2039, 2069, 2099) were run as well as a renovation scenario (Minergie-P). We analyse the impact of climate change on the heating and cooling demand of the buildings and determined the relevance of the accounting of the local climate in this particular context. The results from the simulations showed that in the future there will a constant decrease in the heating demand while for the cooling demand there will be a significant increase. It was further demonstrated that when the local climate was taken into account there was an even higher rise in the cooling demand but also that the proposed renovations were not sufficient to design resilient buildings. We then discuss the implication of this work on the simulation of building energy consumption at the neighbourhood scale and the impact of future local climate on energy system design. We finally give a few perspective regarding improved urban design and possible pathways for the future urban areas.

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Recent responses of grassland net primary productivity to climatic and anthropogenic factors in Kyrgyzstan

10.31219/osf.io/3q6h8 ◽

2020 ◽

Author(s):

Yanwen Wang

Keyword(s):

Climate Change ◽

Primary Productivity ◽

Human Activities ◽

Net Primary Productivity ◽

Anthropogenic Activities ◽

Dominant Factor ◽

Anthropogenic Factors ◽

Grassland Degradation ◽

Contributing Factors ◽

Spatial And Temporal Patterns

Net primary productivity (NPP) is an essential indicator of ecosystem function and sustainability and plays a vital role in the carbon cycle, especially in arid and semi-arid grassland ecosystems. Quantifying trends in NPP and identifying the contributing factors are important for understanding the relative impacts of climate change and human activities on grassland degradation. We quantified spatial and temporal patterns in potential NPP (NPPP) and actual NPP (NPPA) in Kyrgyzstan from 2000 to 2014 based on the Zhou Guangsheng model and MOD17A3 NPP data, respectively. By calculating the difference between NPPP and NPPA, we inferred human-induced NPP (NPPH) and thereby characterised changes in grassland NPP attributable to anthropogenic activities. We found that over the past two decades, both climatic variation and anthropogenic activities have significantly affected Kyrgyzstan’s grasslands. Grassland NPP decreased overall but patterns varied between provinces. Climate change, in particular changes in precipitation was the dominant factor driving grassland degradation in the north but human pressures also contributed. In the south however, human activities were associated with extensive areas of grassland recovery. The results provide important contextual understanding for supporting policy for grassland maintenance and restoration under climate change and intensifying human pressures.

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