Lake Shrinkage Research Articles

Shrinkage of Nepal’s Second Largest Lake (Phewa Tal) Due to Watershed Degradation and Increased Sediment Influx

Phewa Lake is an environmental and socio-economic asset to Nepal and the city of Pokhara. However, the lake area has decreased in recent decades due to sediment influx. The rate of this decline and the areal evolution of Phewa Lake due to artificial damming and sedimentation is disputed in the literature due to the lack of a historical time series. In this paper, we present an analysis of the lake’s evolution from 1926 to 2018 and model the 50-year trajectory of shrinkage. The area of Phewa Lake expanded from 2.44 ± 1.02 km2 in 1926 to a maximum of 4.61 ± 0.07 km2 in 1961. However, the lake area change was poorly constrained prior to a 1957–1958 map. The contemporary lake area was 4.02 ± 0.07 km2 in April 2018, and expands seasonally by ~0.18 km2 due to the summer monsoon. We found no evidence to support a lake area of 10 km2 in 1956–1957, despite frequent reporting of this value in the literature. Based on the rate of areal decline and sediment influx, we estimate the lake will lose 80% of its storage capacity in the next 110–347 years, which will affect recreational use, agricultural irrigation, fishing, and a one-megawatt hydroelectric power facility. Mitigation of lake shrinkage will require addressing landslide activity and sediment transport in the watershed, as well as urban expansion along the shores.

A trade-off method between environment restoration and human water consumption: A case study in Ebinur Lake

The shrinkage of inland lakes has become a major problem in arid region. Human activities are competing for water resources with sustainable lake ecosystem. Considering improving irrigation efficiency does not help on water saving at basin scale and reducing ET through mulching, zero tillage and deficit irrigation will lead to crop yield loss, this study proposed an alternative way that returning cropland to lake to achieve the balance between endorheic lake restoration and human water consumption. The approach consists of four procedures: (1) identifying the target annual inflow (Qtar) of endorheic lake; (2) calculating available consumable water (ACW) in the upstream based on Qtar; (3) setting ET deduction goals using water consumption balance approach; (4) estimating crop area to be deducted. This approach is implemented at Ebinur Lake of China under two restoration scenarios (lake area restored to 522 km2 and 800 km2). The results indicate that to restore the Ebinur Lake to 522 km2, the annual inflow should be increased to 602.6 × 106 m³, and human water consumption should be reduced by 320.3 × 106 m³. If the restoration goal of Ebinur Lake is set to 800 km2, an annual inflow of 876.6 × 106 m³ is required, and the human water consumption should be reduced by 594.2 × 106 m³. The over-expansion of cropland and artificial forest is found to be the main reasons for the shrinkage of Ebinur Lake. Finally, the feasible solutions for ecosystem restoration of Lake Ebinur are provided for both scenarios. The methodology adopted in this research can be applied to the restoration of other inland lakes in arid regions.

Analisis Perubahan Penggunaan Lahan Sekitar Danau Limboto Di Kabupaten Gorontalo

Limboto Lake in Gorontalo Province has been around since 1932 with an area of ± 7,000 Ha. In 1991 the area of the lake shrank to ± 3,644.5 Ha and in 2017 the area of the lake again declined to ± 2,693.9 Ha. The purpose of this research was to identify the type of change in lake land use into non-lake land and the process of changing land use around Limboto Lake. The method used is an overlay analysis of regional Landsat imagery maps around Lake Limboto using the Geographic Information System (GIS) and then described descriptively qualitatively to explain the types and processes of land use change around Limboto Lake from 1991 to 2017. Methods of data collection are secondary data studies related maps of Landsat area images around Limboto Lake in 1991, 2001, 2015, and 2017 and also field observations and interviews to clarify changes in land use that occurred around Limboto Lake from 1991 - 2017. The results of this research indicate that within 26 years (1991 - 2017), there has been a change in the use of lake land around Limboto Lake in the amount of ± 936.56 Ha to agricultural and plantation land, ± 14.29 Ha to become residential land, and ± 0.35 Ha to become a tourist area. The process of changing the physical land use around Limboto Lake, namely: (1) lake land is turned into swamps and then turned into agricultural land (wetlands and dry land) and plantations (coconut); (2) the lake area becomes swamps and then becomes agricultural land (wetlands and dry land) and then turns into residential land; (3) lake land changes into residential land; and (4) lake land directly turns into a tourist area. Keywords: Gorontalo Regency, Limboto Lake Depreciation, Land Use Changes

Effects of Cropland Conversion and Climate Change on Agrosystem Carbon Balance of China’s Dryland: A Typical Watershed Study

Remarkable warm‒wet climate shifts and intensive cropland expansion strongly affected carbon (C) cycle and threaten agricultural sustainability in northwest China. In this study, we integrated a process-based ecosystem model and an empirical C bookkeeping model to investigate the coupled and isolated effects of arable land conversions and climate change (CLM) on regional C balance in a typical watershed of northwest China. Results revealed that the farmland area increased by 3367.31 km2 during 1979–2014. The combined effects of CLM with net cropland expansion enlarged the vegetation C (VEGC) and the soil organic C (SOC) stock by 2.83 and 11.83 Tg, respectively, and were strongest in 2008–2014. The conversions between desert grassland and cropland were the major driving forces for regional C balance. Cropland expansion shared equal effects on VEGC increase with CLM, but its effect on SOC increment was 53 times larger than CLM’s. VEGC was more responsive to CLM, whereas SOC gained more benefits from land management. The C sink from reclamation suffered from high water consumption and is facing great threats due to glaciers and mountain lake shrinking and groundwater overpumping. Water-saving irrigation techniques and environmentally friendly water use strategies are essential for local agricultural sustainability.

GEOMORPHOLOGIC CHANGES IN THE COASTLINE OF VISTONIS LIKE, THRACE, Ν GREECE.

The lake Vistonis is a shallow coastal lake about 20 km SE of the city of Xanhti; in Greek Thrace. It constitutes one of the most important hydrobiotope of Thrace. The lake has an area 45χ106 m 2 and a total volume of water 106*106 m . It accepts today around 330.000 m 3/yr sediments and a total volume of 360><106 m3/sec fresh water from the surrounding basin. Due to human intervention to drainage system of the basin i.e. entrenchment of the torrent channels and diversion of their courses (river Kosinhtos),etc, the solid load reaching the lake increased a lot during the last decades resulting in the increase sedimentation inside the lake. As a result the rate of the lake shrinkage increased. Besides that the lake suffer from eutrophication due to fertilizers brought with river waters. In this paper the changes in the lake's shoreline the last 170 year is discussed. As it is shown the lake's coastline exhibits prograduction (advance) at its north and east side and erosion and retreat at the south and west side. This is attributed to the distribution of the incoming sediment and to the prevailing, in the area, NE and SE winds.

Holocene thermokarst and pingo development in the Kolyma Lowland (NE Siberia)

AbstractGround ice and sedimentary records of a pingo exposure reveal insights into Holocene permafrost, landscape and climate dynamics. Early to mid‐Holocene thermokarst lake deposits contain rich floral and faunal paleoassemblages, which indicate lake shrinkage and decreasing summer temperatures (chironomid‐based TJuly) from 10.5 to 3.5 cal kyr BP with the warmest period between 10.5 and 8 cal kyr BP. Talik refreezing and pingo growth started about 3.5 cal kyr BP after disappearance of the lake. The isotopic composition of the pingo ice (δ18O − 17.1 ± 0.6‰, δD −144.5 ± 3.4‰, slope 5.85, deuterium excess −7.7± 1.5‰) point to the initial stage of closed‐system freezing captured in the record. A differing isotopic composition within the massive ice body was found (δ18O − 21.3 ± 1.4‰, δD −165 ± 11.5‰, slope 8.13, deuterium excess 4.9± 3.2‰), probably related to the infill of dilation cracks by surface water with quasi‐meteoric signature. Currently inactive syngenetic ice wedges formed in the thermokarst basin after lake drainage. The pingo preserves traces of permafrost response to climate variations in terms of ground‐ice degradation (thermokarst) during the early and mid‐Holocene, and aggradation (wedge‐ice and pingo‐ice growth) during the late Holocene.

The importance of lakes for bat conservation in Amazonian rainforests: an assessment using autonomous recorders

AbstractRecent studies predict a future decrease in precipitation across the tropics, particularly the Amazon, likely causing significant droughts that have negative consequences for Amazonian freshwater biomes, especially lakes. Furthermore, immediate consequences of global warming for terrestrial fauna associated with tropical lakes are poorly understood as the vast majority of studies come from temperate regions. Here, we assess the seasonal importance of lakes for the conservation of aerial insectivorous bats in the Central Amazon using passive bat recorders. We compared richness, general bat activity and foraging activity between lakes and adjacent forest. Of a total of 21 species/sonotypes recorded in both habitats, all were detected over lakes, and 18 were significantly more active over lakes than in forest. Only two species had significantly higher activity levels in the forest than at the lakes. Species richness and general bat activity over the lakes were higher in the dry than in the rainy season. Foraging activity was also greater over the lakes than within the forest in both seasons. Moreover, both variables were positively correlated with lake size, although the effect on activity was species‐specific. Climate change‐driven shrinking of lakes may have detrimental consequences for aerial insectivorous bats, especially for the most water‐dependent species. Compared to permanent water bodies of other regions, the value of tropical lakes for functionally important taxa, such as bats, has been understudied. Higher bat activity levels over lakes than in forest in both seasons and comprising the whole ensemble of aerial insectivorous bats of the study region, indicate that lakes embedded in Amazonian terra firme forests deserve special attention for future bat conservation.

CONTINUOUS CHANGE DETECTION OF URBAN LAKES IN WUHAN, CHINA USING MULTI-TEMPORAL REMOTE SENSING IMAGES

Abstract. Urban lakes are important natural, scenic and pattern attractions of the city, and they are potential development resources as well. However, lots of urban lakes in China have been shrunk significantly or disappeared due to rapid urbanization. In this study, four Landsat images were used to perform a case study for lake change detection in downtown Wuhan, China, which were acquired on 1991, 2002, 2011 and 2017, respectively. Modified NDWI (MNDWI) was adopted to extract water bodies of urban areas from all these images, and OTSU was used to optimize the threshold selection. Furthermore, the variation of lake shrinkage was analysed in detail according to SVM classification and post-classification comparison, and the coverage of urban lakes in central area of Wuhan has decreased by 47.37 km2 between 1991 and 2017. The experimental results revealed that there were significant changes in the surface area of urban lakes over the 27 years, and it also indicated that rapid urbanization has a strong impact on the losses of urban water resources.

Asia and Climate Change: How It Will Play Out From the Bosporus to Djakarta

Now that the measure of CO2 emissions has broken through 410 on the standard Keeling curve (Earth CO2 website), one may start drawing a scenario for climate change repercussions, here for the Asian continent. It pollutes most of all continents in terms of both greenhouse gases and many other pollutants. The threats to mankind comes in the form of sea level rise, fresh water shortage, less of potable water, shrinking of lakes and rivers, deoxygenation of oceans, less fish food and agriculture produce, energy shortages, omnipresent air conditioning, urban smog, water and sea pollution due to sewage and failures with landfills. Asia, hosting more than half of mankind, will suffer massively from global warming with millions of ecological refugees. The UN’s program, the COP21 by the UNFCCC, cannot stop Asia from reaching Hawking irreversibility, because it entails too weak global governance that is cheatable. The promise of complete decarbonisation is an illusion.

Impacts of Climate Change on Tibetan Lakes: Patterns and Processes

High-altitude inland-drainage lakes on the Tibetan Plateau (TP), the earth’s third pole, are very sensitive to climate change. Tibetan lakes are important natural resources with important religious, historical, and cultural significance. However, the spatial patterns and processes controlling the impacts of climate and associated changes on Tibetan lakes are largely unknown. This study used long time series and multi-temporal Landsat imagery to map the patterns of Tibetan lakes and glaciers in 1977, 1990, 2000, and 2014, and further to assess the spatiotemporal changes of lakes and glaciers in 17 TP watersheds between 1977 and 2014. Spatially variable changes in lake and glacier area as well as climatic factors were analyzed. We identified four modes of lake change in response to climate and associated changes. Lake expansion was predominantly attributed to increased precipitation and glacier melting, whereas lake shrinkage was a main consequence of a drier climate or permafrost degradation. These findings shed new light on the impacts of recent environmental changes on Tibetan lakes. They suggest that protecting these high-altitude lakes in the face of further environmental change will require spatially variable policies and management measures.

Water Spread Area Dynamic of Chilika Lake: A Geospatial Approach

Chilika lake is the largest lagoon in Asia on the east coast peninsular India covering about hundred thousand hectares of land, one among six Indian wetlands declared under the Ramsar convention in 1982. Lake shrinkage is another important ecological transformation. This may be due to several factors, both natural and human. The study area is Chilika Lake which is located at 19°27’58.081”N–19°53’24.438”N latitude and 85°6’5.301”E–85°40’36.149”E longitude on the east-coast of the state of Odisha, India. The objective is to prepare a database of the pre and post monsoon period water spread area of the lake from time series satellite imageries. The geospatial technique has emerged as the most important tool of a geographer to handle the spatio-temporal data. It is now widely used around the world to analyse physical as well as cultural geographical elements. The output will be utilized in several regional and micro level planning, monitoring and management for community development. Keywords: Ecosystem, spatio-temporal, sustainability, time series Cite this Article Jajnaseni Rout, Pattnaik AK, Sasmita Lenka et al . Water Spread Area Dynamic of Chilika Lake: A Geospatial Approach. Journal of Remote Sensing & GIS. 2017; 8(3): 17–21p.

Impact of Rapid Urbanization on Vulnerability of Land System from Complex Networks View: A Methodological Approach

Rapid urbanization is responsible for the increased vulnerability of land systems and the loss of many crucial ecosystem services. Land systems are typical complex systems comprised of different land use types which interact with each other and respond to external environment processes (such as urbanization), resulting in dynamics in land systems. This work develops a methodology approach by integrating complex networks and disruptive scenarios and applies it to a case study area (Wuhan City in China) to explore the effects of urbanization on land system structural vulnerability. The land system network topologies of Wuhan City during five time periods from 1990 to 2015 are extracted. Our results reveal that (1) the urban land expands at a higher speed than the urban population in Wuhan City; (2) the period of 2005–2010 has witnessed more land area conversions from ecological lands to urban land than other periods; (3) the land system is more vulnerable to intentional attacks on nodes with higher integrated node centrality and larger land area, such as paddy, dryland, and lake; and (4) the network efficiency of the land system would decline sharply if the area shrinkage of paddy, dryland, and lake is larger than 30%, 50%, and 20%, respectively. The results provide some insights into building a resilient urban land system, such as increasing the efficiency of existing urban land and controlling the shrinkage rate of important land use types. This study contributes to existing literature on complex networks by expanding its application in land systems, which highlight the potential of complex networks to capture the complexity, dynamics, heterogeneity, and emergent phenomena in land systems.

Monitoring dynamics and driving forces of lake changes in different seasons in Xinjiang using multi-source remote sensing

ABSTRACTLakes are important for ensuring the development of the regional economy and ecological security. Based on MODIS and Landsat TM/OLI remote sensing images captured in 2005-2015 and a Combined Water Index (CWI), this paper extracted information on changes in the temporal and spatial characteristics and driving forces for lake areas in Xinjiang during past 11 years in different seasons (April, July and September). The results showed that over this time period, the area of the lakes exhibited an increasing trend. The largest surface area usually occurred in April, and the lowest value was measured in September. The lake shrinkage area in Xinjiang occurred mainly in Northern Xinjiang and the northeastern region of Southern Xinjiang, whereas the lake expansion area was concentrated in Eastern Xinjiang. Seasonal changes in Manas, Kanas, Barkol, Arkatag, Arik and Ebinur Lakes showed higher trends. Extracted the lake area based on the MODIS and TM/OLI image were analyzed, and both had a good corresponding relationship. The minimum R2 was 0.548, and maximum RMSE was 44.1km2. Therefore, it was feasible to use MODIS to extract lake area. These changes in lake area resulted from both natural factors and human activities, and coupled effects greatly accelerated local environmental changes.

Shifts in the community composition of methane-cycling microorganisms during lake shrinkage

Intensification of anthropogenic activities has resulted in shrinkage of lakes, which are important sources and sinks of the greenhouse gas methane. Given the increasing interest in the potential importance of CH4 flux, we employed Illumina Miseq pyrosequencing to examine the effect of lake shrinkage (in a lake that had decreased from 3.7km2 to 3.0km2 in area during the last 20years) on the community abundance, activity and structure of methane-cycling microorganisms under four types of soils during lake recession: Sediment (the sediment of the lake, at the maximum depth of 6m), Slope (soil at a lake water depth of 0.6m), Marsh (the seasonally flooded marsh and wetland formed after recession of the lake) and Meadow (the meadow formed after recession of the lake, about 200m from the lake). The results showed that lake shrinkage decreased the relative abundance and transcripts of soil methanogens and methanotrophs along the gradient from Sediment to Slope to Marsh. Meadow, having the longest drying time, had both higher soil nutrient concentrations (including dissolved organic carbon, total carbon and total nitrogen), and higher relative abundance of 16S rRNA genes and transcripts of methanogens and methanotrophs. Results of methanogen community structure analysis indicated ‘resistance’ to change under lake shrinkage, with all communities dominated by Methanosaetaceae except the Slope community, which was dominated by Methanoregulaceae, while the dominant methanotroph changed from Methylomicrobium (a Type I methanotroph) (in Sediment, Slope and Marsh) to Methylocaldum (Type I) and Methylosinus (Type II) (in Meadow) under lake shrinkage. Taken together, the microbial community data indicate that CH4 production and consumption potentially recedes under lake shrinkage, whereas the formation of Meadow may increase CH4 emission and oxidization potential.

Application of Landsat Imagery to Investigate Lake Area Variations and Relict Gull Habitat in Hongjian Lake, Ordos Plateau, China

Lakes in arid and semi-arid regions have an irreplaceable and important role in the local environment and wildlife habitat protection. Relict Gull (Larus relictus), which is listed as a “vulnerable” bird species in the IUCN Red List, uses only islands in lakes for habitat. The habitat with the largest colonies in Hongjian Lake (HL), which is located in Shaanxi Province in China, has been severely threatened by persistent lake shrinkage, yet the variations in the area of the lake and the islands are poorly understood due to a lack of in situ observations. In this study, using the Modified Normalized Difference Water Index, 336 Landsat remote sensing images from 1988–2015 were used to extract the monthly HL water area and lake island area, and the driving factors were investigated by correlation analysis. The results show that the lake area during 1988–2015 exhibited large fluctuations and an overall downward trend of −0.94 km2/year, and that the lake area ranged from 55.02 km2 in 1997 to 30.90 km2 in 2015. The cumulative anomaly analysis diagnosed the lake variations as two sub-periods with different characteristics and leading driving factors. The average and change trend were 52.88 and 0.21 km2/year during 1988–1998 and 38.85 and −1.04 km2/year during 1999–2015, respectively. During 1988–1998, the relatively high precipitation, low evapotranspiration, and low levels of human activity resulted in a weak increase in the area of HL. However, in 1999–2015, the more severe human activity as well as climate warming resulted in a fast decrease in the area of HL. The variations in lake island area were dependent on the area of HL, which ranged from 0.02 km2 to 0.22 km2. As the lake size declined, the islands successively outcropped in the form of the four island zones, and the two zones located in Northwest and South of HL were the most important habitats for Relict Gull. The formation of these island zones can provide enough space for Relict Gull breeding.

Dynamic of Dalinor Lakes in the Inner Mongolian Plateau and Its Driving Factors during 1976–2015

Climate change and increasing human activities have induced lake expansion or shrinkage, posing a serious threat to the ecological security on the Inner Mongolian Plateau, China. However, the pattern of lake changes and how it responds to climate change and revegetation have rarely been reported. We investigated the pattern of lake-area changes in the Dalinor National Nature Reserve (DNR) using Landsat imagery during 1976–2015, and examined its relationship with changes in climate and vegetation factors. The total lake-area in the DNR has decreased by 11.6% from 1976 to 2015 with a rate of −0.55 km2 year−1. The largest Dalinor Lake reduced the most (by 32.7 km2) with a rate of −0.79 km2 year−1. The air temperature has increased significantly since 1976, with a rate of 0.03 °C year−1 (p < 0.05), while the precipitation slightly decreased during 1976–2015, with a rate of −0.86 mm year−1. The Normalized Difference Vegetation Index (NDVI) increased by 27.7% from 1976 to 2015, especially after 2001 when vegetation has been promoted greatly as a result of the successful ecological protection and restoration in the Dalinor basin. The decrease in lake-areas for the DNR exhibited a negative correlation with NDVI (r = −0.397, p < 0.05) during 1976–2015. It seems that decreasing precipitation drives the reduction in lake-area, while rising temperature and vegetation greenness accelerated this decreasing trend by increasing evapotranspiration. The continuous lake shrinkage increases the ecological risks to the habitat of birds, causing a challenge to the management in the DNR.

Spatiotemporal change patterns of urban lakes in China’s major cities between 1990 and 2015

ABSTRACTChina has experienced unprecedented urbanization in the past decades, resulting in dramatic changes in the physical, limnological, and hydrological characteristics of lakes in urban landscapes. However, the spatiotemporal dynamics in distribution and abundance of urban lakes in China remain poorly understood. Here, we characterized the spatiotemporal change patterns of urban lakes in China’s major cities between 1990 and 2015 using remote-sensing data and landscape metrics. The results showed that the urban lake landscape patterns have experienced drastic changes over the past 25 years. The total surface area of the urban lakes has decreased by 17,620.02 ha, a decrease of 24.22%, with a significant increase in the landscape fragmentation and a reduction in shape complexity. We defined three lake-shrinkage types and found that vanishment was the most common lake-shrinkage pattern, followed by edge-shrinkage and tunneling in terms of lake area. Moreover, we also found that urban sprawl was the dominant driver of the lake shrinkage, accounting for 67.89% of the total area loss, and the transition from lakes to cropland was also an important factor (19.86%). This study has potential for providing critical baseline information for government decision-making in lake resources management and urban landscape design.

Lake dynamics and its relationship to climate change on the Tibetan Plateau over the last four decades

The high sensitivity of the Tibetan Plateau (TP) to global warming is ascribed not only to its high altitude and low temperature but also to the change in the components of water cycling, such as glaciers’ retreat, permafrost degradation, and lakes’ shrinkage or expansion. Among the components, change in lakes attracts more attention as lakes are crucial for local water management and are easier to monitor. But, how water cycling components respond to global change remains unclear, although they are crucial in understanding the regional environmental change. Lakes, glaciers, and permafrost data derived from meteorological records and remote sensing images were used to detect the change of the water environment on the TP from 1971 to 2013. The climate on TP changed toward a warm-humid condition in the last four decades. Three-quarters of the lakes were significantly expanded over the TP, and the summed area of all the lakes increased by 6061 km2 from 1975 to 2010. Panel regression showed that annual average air temperature (T), annual precipitation (P), and reference crop evapotranspiration (ET o ) regulate the change in lake surface area (LSA) on the entire TP. The change in LSA is more related to the change in P than in the other two factors, even in the catchment where lakes are recharged by water from glacier melting and permafrost degradation, especially in extremely arid and arid climate zones. Elevation and size affected the sensitivity of lakes to climate change with lakes in a high-elevation area more sensitive to T and small lakes more sensitive to T, P, and ET o . Warming-induced glacier’s retreat led to the significant lake expansion, while permafrost degradation might be responsible for the lake shrinkage in the seasonally frozen ground area due to the related cryogenic waterproof layer downward. Our results about the responses of lakes to climate change in different catchments were in accordance with the findings of previous studies about several typical lakes, which implied that overall response of all the lakes to climate change could be obtained by examining several typical lakes in the catchment level.

A multi-proxy lacustrine record of last deglacial–early Holocene environmental variability in the lower Yangtze region from the Chaohu Lake Basin, eastern China

AbstractThe Rb, Sr, and Ti content, Rb/Sr ratio, grain size, magnetic susceptibility, and magnetic fabric in sediments of the BZK1 core were utilized to reconstruct the evolution of the climatic environment in the Chaohu Lake Basin between the last deglacial and the early Holocene. Multi-proxy analyses indicate that lacustrine sediments in Chaohu Lake clearly record the Bølling-Allerød interstadial, the Younger Dryas event and dry-cold climate events occurring between 10.7 cal ka BP and 10.5 cal ka BP. At approximately 15.6–14.8 cal ka BP, the waters became deeper and the climate turned cool. The climate subsequently shifted to a relatively humid period and the lake was largest from 14.8 to 12.8 cal ka BP. From 12.8 to 11.7 cal ka BP, the climate abruptly turned dry and cold and the lake shrank to its lowest level. During 11.7–10.7 cal ka BP, the climate became relatively humid but, from approximately 10.7 to 10.5 cal ka BP, suddenly reverted to a dry and cold state. These climatic change records suggest that lacustrine sediments from the Chaohu Lake Basin in the lower Yangtze region responded actively to global climate changes, comparable with the environmental records from stalagmites and other lacustrine sediments in the region.

The cause of rapid lake expansion in the Tibetan Plateau: climate wetting or warming?

Endorheic lake dynamics in the Tibetan Plateau (TP), as reflected in changes in water level and/or surface area, are sensitive indicator of regional hydrology that is closely related to both climate change and cryosphere hydrology. Since the late 1990s, most closed lakes in the interior TP expanded and deepened dramatically, in sharp contrast with lake shrinkage in the southern TP. Although some evidence shows that glacier melting and permafrost thawing within some lakes may influence lake level changes, they cannot explain the overall lake expansion, especially for lakes without glacier supply. More and more evidence from lake water balance modeling indicated that the overall lake expansion across the interior TP may be mainly attributed to a significant increase in precipitation and associated runoff. The positive lake water budget is also consistent with regional climate changes (e.g., increase in water vapor content and air convection in the interior TP), with relevant changes in large‐scale atmospheric circulation to be investigated. Further studies are needed to quantify the contribution of each component to lake water budgets and the associated climate change. WIREs Water 2017, 4:e1236. doi: 10.1002/wat2.1236This article is categorized under: Science of Water > Hydrological Processes Water and Life > Stresses and Pressures on Ecosystems Science of Water > Water and Environmental Change