The changing water cycle: Burabay National Nature Park, Northern Kazakhstan

Water resources in Central Asia are scarce, so complicated issues arise from this. Kazakhstan is a Central Asian landlocked country which has mostly closed drainage basins, characterized by endorheic lakes that do not drain to the oceans. These endorheic lakes are very sensitive to climate change and anthropogenic influences. Very few studies have been conducted on the hydrological cycle of the small endorheic lakes. This work reviews the endorheic lakes within Burabay National Nature Park (BNNP), Northern Kazakhstan. BNNP is a small ecozone consisting of terminal lakes watersheds covered by mixed forests and grasslands. These endorheic lakes have been drying out during the last one hundred years or so with the water level decrease accelerated in the past few decades. According to historical observations (1935-2014), on the one hand precipitation amounts did not significantly change, while on the other hand, air temperature steadily increased. The lake level decrease is most probably caused by a water budget deficit, with evaporation exceeding the precipitation inputs in the long-term. The direct anthropogenic impact (water abstraction) plays a minor role in deterioration of water levels, with most significant impacts through localized land use changes such as road and building construction in the catchments. The future of the park’s sensitive ecosystems in a changing climate is uncertain; therefore, BNNP requires modern ecohydrological monitoring methods and analysis tools to improve our understanding of its hydrological cycle variability, and to enable us to develop adequate adaptation and mitigation measures

Observation-Based Algorithm Development For Subsurface Hydrology In Northern Temperate Wetlands

This study investigates wetland subsurface hydrology, as well as biogeochemistry - which is strongly influenced by water and temperature dynamics - as these interactions are expected to be highly significant, yet remain poorly represented in current ecosystem and climate models. Northern wetlands have received widespread public attention due to steadily increasing summer mean global temperatures, extreme precipitation events and higher rates of natural greenhouse gas emissions, as well as the significant impacts on them due to human activities. The goal of my graduate research has been to improve quantification of the role of subsurface hydrology in northern wetlands by using a macroscale hydrological model, the Variable Infiltration Capacity (VIC) model. The existing VIC model was modified to better represent the effect of surface and subsurface water storage in managed wetlands. An improved water table depth calculation, based on a drained to equilibrium assumption, was incorporated into a new subsurface drainage algorithm. The spatial variability of water table depth across landscape positions has been represented using a topographic index approach. By incorporating a water table gradient into the VIC grid cell, subsurface-surface water exchange within the wetland can also be represented, dependent on land surface class. This algorithm was developed and evaluated using data at scales ranging from field to small watershed, which included a small wetland at the Agronomy Center for Research and Education (ACRE), the long-term drainage experiment at the Davis-Purdue Agricultural Center (DPAC), and a cooperators mint farm in Pulaski, Indiana. The improved model has been used at larger scales - from large watersheds to regional scale - to better understand the subsurface hydrology affected by drainage practices throughout the poorly-drained Midwest agricultural regions. Recent concern regarding high rates of soil organic matter decomposition due to artificial drainage enhancements motivated an integrated field and modeling experiment to quantify the influence of water management on cultivated organic soils in the Kankakee River basin, a flat outwash plain covered with relatively deep, poorly drained soil with high organic matter content. Methane and carbon dioxide emissions were simulated by using soil temperature, water table position and net primary production generated from the VIC model and evaluated using CO2 flux measurements, water table height and soil moisture measurements. The model simulations do support the high rates of subsidence previously reported for these high organic matter soils, but most of the subsidence took place soon after the introduction of agricultural drainage. Another case study evaluated the role of anthropogenic modifications to drainage conditions and wetland extent on streamflow in the upper Wabash River basin. An initial test case demonstrated that a depressional wetland perched on the Tipton Till Plain tends to recharge soil moisture in riparian areas by late summer, reducing the volume of baseflow downstream. When scaled up to the upper Wabash River basin , the study demonstrated that wetlands provided more temporal surface water storage and served to reduce peak flows. Subsurface drainage increased the high flow, mean flow, and Richard-Baker flashiness Index (RBI), and reduced the low flow and flow distribution. Stream network density analysis showed that simulations with lower drainage density (representing historic, natural conditions) had relatively lower high flow and smaller RBI. These results provide evidence that although drainage creates more pore space in the soil profile - reducing surface runoff - it also creates more flow paths, allowing water to travel to the watershed outlet more quickly

What is the future for Central Asian endorheic lakes? A water balance model for Shortandy Lake, Burabay National Nature Park, Kazakhstan

Lakes are recognised as having a high sensitivity to environmental change and human interventions. This is particularly the case with endorheic lakes due to the fact that their water volume is not controlled by outflow from a river outlet. Most of the endorheic lakes are formed in dry, i.e. in arid or/and semi-arid regions. Central Asia occupies one-third of the arid area of the world, where lakes are a valuable source of freshwater for irrigation and daily usage. This thesis investigates the reasons for the lake volume decline in Shortandy Lake; one of the endorheic lakes located in Burabay National Nature Park (BNNP) in Northern Kazakhstan. BNNP was established in order to preserve and restore the unique landscape of the region, which plays an important role in ecologic, scientific and recreational dimensions. The Park consists of a number of endorheic lakes, in which water volumes have been fluctuating during the last century. However, the reasons for the current trends in water volume reduction in the Burabay lakes system remain unexplored. This PhD project develops and validates a new water balance model for Shortandy Lake that is built from fundamental hydrological relationships. The water level and volume of the lake is estimated monthly using estimates of daily open water and grass evaporation, snowmelt and rainfall-induced runoff from observed climate variables available from the State Hydro-meteorological agency. Crucially, it also incorporates estimates of anthropogenic water abstraction. The water balance model is applied to assess future water volume changes under changing future climate scenarios. The analysis reveals new information on the potential impacts of regional climate fluctuation as well as allowing assessment of the impact of past and future water management strategies in the Shortandy Lake catchment

Earth Resources: a continuing bibliography with indexes

This bibliography lists 337 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 31, 1980 and September 30, 1980. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economic analysis

Responses and adaptation strategies of terrestrial ecosystems to climate change

Terrestrial ecosystems are likely to be affected by climate change, as climate change-induced shift of water and heat stresses patterns will have significant impacts on species composition, habitat distribution, and ecosystem functions, and thereby weaken the terrestrial carbon (C) sink and threaten global food security and biofuel production. This thesis investigates the responses of terrestrial ecosystems to climate change and is structured in four main chapters.;The first chapter of the thesis is directed towards the impacts of snow variation on ecosystem phenology. Variations in seasonal snowfall regulate regional and global climatic systems and vegetation growth by changing energy budgets of the lower atmosphere and land surface. We investigated the effects of snow on the start of growing season (SGS) of temperate vegetation in China. Across the entire temperate region in China, the winter snow depth increased at a rate of 0.15 cm•yr-1 (p=0.07) during the period 1982-1998, and decreased at a rate of 0.36 cm•yr-1 (p=0.09) during the period 1998-2005. Correspondingly, the SGS advanced at a rate of 0.68 d•yr-1 (p\u3c0.01) during 1982 to 1998, and delayed at a rate of 2.13 d•yr-1 (p=0.07) during 1998 to 2005, against a warming trend throughout the entire study period of 1982-2005. Spring air temperature strongly regulated the SGS of both deciduous broad-leaf and coniferous forests; whilst the winter snow had a greater impact on the SGS of grassland and shrubs. Snow depth variation combined with air temperature contributed to the variability in the SGS of grassland and shrubs, as snow acted as an insulator and modulated the underground thermal conditions. Additionally, differences were seen between the impacts of winter snow depth and spring snow depth on the SGS; as snow depths increased, the effect associated went from delaying SGS to advancing SGS. The observed thresholds for these effects were snow depths of 6.8 cm (winter) and 4.0 cm (spring). The results of this study suggest that the response of the vegetation\u27s SGS to seasonal snow change may be attributed to the coupling effects of air temperature and snow depth associated with the soil thermal conditions.;The second chapter further addresses snow impacts on terrestrial ecosystem with focus on regional carbon exchange between atmosphere and biosphere. Winter snow has been suggested to regulate terrestrial carbon (C) cycling by modifying micro-climate, but the impacts of snow cover change on the annual C budget at the large scale are poorly understood. Our aim is to quantify the C balance under changing snow depth. Here, we used site-based eddy covariance flux data to investigate the relationship between snow cover depth and ecosystem respiration (Reco) during winter. We then used the Biome-BGC model to estimate the effect of reductions in winter snow cover on C balance of Northern forests in non-permafrost region. According to site observations, winter net ecosystem C exchange (NEE) ranged from 0.028-1.53 gC•m-2•day-1, accounting for 44 +/- 123% of the annual C budget. Model simulation showed that over the past 30 years, snow driven change in winter C fluxes reduced non-growing season CO2 emissions, enhancing the annual C sink of northern forests. Over the entire study area, simulated winter ecosystem respiration (Reco) significantly decreased by 0.33 gC•m-2•day -1•yr-1 in response to decreasing snow cover depth, which accounts for approximately 25% of the simulated annual C sink trend from 1982 to 2009. Soil temperature was primarily controlled by snow cover rather than by air temperature as snow served as an insulator to prevent chilling impacts. A shallow snow cover has less insulation potential, causing colder soil temperatures and potentially lower respiration rates. Both eddy covariance analysis and model-simulated results showed that both Reco and NEE were significantly and positively correlated with variation in soil temperature controlled by variation in snow depth. Overall, our results highlight that a decrease in winter snow cover restrains global warming through emitting less C to the atmosphere.;The third chapter focused on assessing drought\u27s impact on global terrestrial ecosystems. Drought can affect the structure, composition and function of terrestrial ecosystems, yet the drought impacts and post-drought recovery potential of different land cover types have not been extensively studied at a global scale. Here, we evaluated drought impacts on gross primary productivity (GPP), evapotranspiration (ET), and water use efficiency (WUE) of different global terrestrial ecosystems, as well as the drought-resilience of each ecosystem type during the period of 2000 to 2011. We found the rainfall and soil moisture during drought period were dramatically lower than these in non-drought period, while air temperatures were higher than normal during drought period with amplitudes varied by land cover types. The length of recovery days (LRD) presented an evident gradient of high (\u3e 60 days) in mid- latitude region and low (\u3c 60 days) in low (tropical area) and high (boreal area) latitude regions. As average GPP increased, the LRD showed a significantly decreasing trend among different land covers (R 2=0.53, p\u3c0.0001). Moreover, the most dramatic reduction of the drought-induced GPP was found in the mid-latitude region of north Hemisphere (48% reduction), followed by the low-latitude region of south Hemisphere (13% reduction). In contrast, a slightly enhanced GPP (10%) was showed in the tropical region under drought impact. Additionally, the highest drought-induced reduction of ET was found in the Mediterranean area, followed by Africa. The water use efficiency, however, showed a pattern of decreasing in the north Hemisphere and increasing in the south Hemisphere.;The last chapter compared the differences of performance in trading water for carbon in planted forest and natural forest, with specific focus on China. Planted forests have been widely established in China as an essential approach to improving the ecological environment and mitigating climate change. Large-scale forest planting programs, however, are rarely examined in the context of tradeoffs between carbon sequestration and water yield between planted and natural forests. We reconstructed evapotranspiration (ET) and gross primary production (GPP) data based on remote-sensing and ground observational data, and investigated the differences between natural and planted forests, in order to evaluate the suitability of tree-planting activity in different climate regions where the afforestation and reforestation programs have been extensively implemented during the past three decades in China. While the differences changed with latitude (and region), we found that, on average, planted forests consumed 5.79% (29.13mm) more water but sequestered 1.05% (-12.02 gC m-2 yr -1) less carbon than naturally generated forests, while the amplitudes of discrepancies varied with latitude. It is suggested that the most suitable lands in China for afforestation should be located in the moist south subtropical region (SSTP), followed by the mid-subtropical region (MSTP), to attain a high carbon sequestration potential while maintain a relatively low impact on regional water balance. The high hydrological impact zone, including the north subtropical region (NSTP), warm temperate region (WTEM), and temperate region (TEM) should be cautiously evaluated for future afforestation due to water yield reductions associated with plantations

What is the future for Central Asian endorheic lakes? A water balance model for Shortandy Lake, Burabay National Nature Park, Kazakhstan

Lakes are recognised as having a high sensitivity to environmental change and human interventions. This is particularly the case with endorheic lakes due to the fact that their water volume is not controlled by outflow from a river outlet. Most of the endorheic lakes are formed in dry, i.e. in arid or/and semi-arid regions. Central Asia occupies one-third of the arid area of the world, where lakes are a valuable source of freshwater for irrigation and daily usage. This thesis investigates the reasons for the lake volume decline in Shortandy Lake; one of the endorheic lakes located in Burabay National Nature Park (BNNP) in Northern Kazakhstan. BNNP was established in order to preserve and restore the unique landscape of the region, which plays an important role in ecologic, scientific and recreational dimensions. The Park consists of a number of endorheic lakes, in which water volumes have been fluctuating during the last century. However, the reasons for the current trends in water volume reduction in the Burabay lakes system remain unexplored. This PhD project develops and validates a new water balance model for Shortandy Lake that is built from fundamental hydrological relationships. The water level and volume of the lake is estimated monthly using estimates of daily open water and grass evaporation, snowmelt and rainfall-induced runoff from observed climate variables available from the State Hydro-meteorological agency. Crucially, it also incorporates estimates of anthropogenic water abstraction. The water balance model is applied to assess future water volume changes under changing future climate scenarios. The analysis reveals new information on the potential impacts of regional climate fluctuation as well as allowing assessment of the impact of past and future water management strategies in the Shortandy Lake catchment

Diagnosis and Improvement of Cryosphere Shortwave Radiation Biases in Global Climate Models.

Faithful representation of cryospheric change is critical for accurate climate modeling, but there are complicating issues in representing snow extent and reflectance in physically realistic ways. This thesis is a collection of diagnostics and improvements of cryospheric shortwave radiation in climate models. Firstly, we incorporate a diagnostic called the cryosphere radiative effect (CrRE), the instantaneous influence of surface snow and sea ice on the top-of-model solar energy budget, into two released versions of the Community Earth System Model. CrRE offers a more climatically relevant metric of the cryospheric state than snow and sea ice extent and is influenced by factors such as the seasonal cycle of insolation, cloud masking, and vegetation cover. We evaluate CrRE during the late 20th century and over the 21st century, specifically diagnosing the CrRE contributions from terrestrial and marine sources. Present-day boreal CrRE compares well with observationally derived estimates. Similar present-day CrRE in the two model versions results from compensating differences in cloud masking and sea ice extent. Radiative forcing in future warming scenarios reduces boreal and austral sea ice cover, and boreal snow cover, which each contribute roughly 1 W/m-2 to enhancing global absorbed shortwave radiation. Similar global cryospheric albedo feedbacks between 0.41-0.45 W/m2/K indicate the models exhibit similar temperature-normalized CrRE change. Secondly, we incorporated a modified canopy scheme into the Community Land Model with snow interception as a prognostic variable and snow unloading tuned to in-situ measurements. The canopy radiation scheme has been updated from a direct temperature dependence of optical parameters to a dependence on the prognostic snow storage. With these improvements, boreal forest zones show large, significant albedo error reductions relative to MODIS observations. 13% gridcell RMSE reduction during spring results from a more gradual seasonal transition in albedo, while 27% reduction in winter is from a lower albedo. Over all North Hemisphere land area, error was also reduced. Thirdly, we assess the impacts of the snow canopy vegetation treatment in coupled model warming scenarios. Little change in global albedo feedback or climate sensitivity were shown, but significant alterations resulted that varied both regionally and temporally.PhDApplied PhysicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113453/1/perketj_1.pd

Earth resources: A continuing bibliography with indexes (issue 52)

This bibliography lists 454 reports, articles, and other documents introduced into the NASA scientific and technical information system between October 1 and December 31, 1986. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economic analysis

Quantifying Errors in Large Scale Water Balance

Assessment and prediction of the effects of Arctic river flows on ocean circulation and climate are hindered by lack of knowledge about the terrestrial water balance. This study quantifies the components of the annual water budget (precipitation, streamflow, and evapotranspiration) and their uncertainty for a large Russian river basin. Over long periods, assuming negligible change in storage, inputs and outputs should balance. However, measurement limitations and errors lead to nonzero water balance closure (WBC). The variance of WBC, computed by summing the component variances, quantifies uncertainty in the water budget. The component terms and their uncertainty are calculated from independent observations and physically-based modeling. For the analysis period, the WBC is negative. The computed uncertainty is large, but not sufficient to conclude that WBC could be zero. Because current assessments do not completely account for the water budget, statements about the effects of climate change must be done cautiously