Massive crop expansion threatens agriculture and water sustainability in Northwestern China

Northwestern China (NWC) is among the major global hotspots undergoing massive terrestrial water storage (TWS) depletion. Yet driver(s) underlying such region-wide depletion remain controversial, i.e., warming-induced glacier-melting versus anthropogenic activities. Reconciling this controversy is the core initial step to guide policy-making for combating the dual challenges in agriculture production and water scarcity in the vastly dry NWC towards sustainable development. Utilizing diverse observations, we found persistent cropland expansion by >1.2×104km2 since 2003, leading to 59.9% growth in irrigated area and 19.5% in agricultural water use, despite a steady irrigation efficiency enhancement. Correspondingly, a substantially faster evapotranspiration increase occurred in crop expansion areas, whereas precipitation exhibited no long-term trend. Counterfactual analyses suggest that the region-wide TWS depletion is unlikely to have occurred without crop expansion-driven evapotranspiration increase even in the presence of glacier-melting. These findings imply that sustainable water management is critically needed to ensure agriculture and water security in NWC.

Anthropogenic Climate Change Drives the Melting of Glaciers in the Himalaya

The Himalayan glaciers supply water to a large population in south Asia for various uses and ecosystem services. Therefore, regional monitoring of glacier melting and identifying the drivers thereof is important to understand and predict the future trends of cryospheric melting. Using multi-date satellite images from 2000-2020, we investigated the shrinkage, snout retreat, thickness changes, mass loss and velocity changes of 77 glaciers in the Drass basin, western Himalaya, India. The overall glacier cover has shrunk by 5.31±0.33 km2 during the period. Snout retreat varied between 30-430 m (mean 155±9.58 m). Debris-cover showed a significant influence on the glacier melting with the clean glaciers showing a higher loss of ~5% compared to the debris-covered glaciers (~2%). The glaciers on an average have shown thickness change and mass loss of -1.27±0.37 and -1.08±0.31 m w.e.a-1 respectively. Average glacier velocity has reduced from 21.35±3.3 m a-1 in 2000 to 16.68±1.9 m a-1 by 2020 due to the continuous melting and the consequent mass loss of the glaciers. Concentration of the greenhouse gases (GHGs), black carbon and other pollutants from vehicular traffic plying in the vicinity of the glaciers has significantly increased during the observation period. Increasing temperatures, result of the significant increase of the GHGs and pollutants in the atmosphere, drive the glacier melting in the study area. If the situation continues in the future, the glaciers may disappear altogether in the Himalaya leading to significant impact on the regional water supplies, hydrological processes, ecosystem services and transboundary sharing of waters.

Changes in glacial lakes in the Poiqu River basin in the central Himalayas

The Poiqu River basin is an area of concentration for glaciers and glacial lakes in the central Himalayas, where 147 glacial lakes were identified, based on perennial remote sensing images, with lake area ranging from 0.0002 to 5.5 km2 – a total of 19.89 km2. Since 2004, the retreat rate of glacier has reached as high as 5.0 km2 a−1, while the growth rate of glacial lake has reached 0.24 km2 a−1. We take five typical lakes as our case study and find that the retreat of glacier area reaches 31.2 %, while the glacial lake area has expanded by 166 %. Moreover, we reconstruct the topography of the lake basin to calculate the water capacity and propose a water balance equation (WBE) to explore the lake evolution. By applying the WBE to the five lakes, we calculate the water supplies of the last few years and compare this with the results of field surveys, which are in agreement, within an error of only 1.86 % on average. The WBE also reveals that the water supplies to the lake depend strongly on the altitude. Lakes at low altitudes are supplied by glacier melting, and lakes at high altitudes are supplied by snowmelts. The WBE is not only applicable for predicting future changes in glacial lakes under climate warming conditions but is also useful for assessing water resources from rivers in the central Himalayas.

FEATURES OF THE FORMATION OF EXTREME EXOGENIC PROCESSES IN THE ALIBEK VALLEY (WESTERN CAUCASUS)

In the mountains, special types of geosystems are formed, whose origins are attributable to exogenic processes - debris flows, avalanches, landslides, etc. Since 2009, a regular survey of key objects and centers of heterogeneous extreme process development has been carried out for their identification and monitoring in the Central Caucasus (the Cherek- Balkarsky basin). To obtain a more complete picture of their course in the Northern Caucasus as a whole, and to track that cycle, the authors considered it expedient, beginning in 2021, to monitor also the Western Caucasus, the area of Teberda and Dombai. The article analyzes the results of expeditionary observations, as well as meteorological indicators that affect the course of extreme exogenic processes, their derivatives for 2020 and for the first eight months of 2021, from the Teberda and Terskol meteorological observatories.On the left side of the Alibek River valley, the predominant processes are talus and, to a lesser extent, avalanches. That side has a southern exposure and is arid relative to the right, northern one. On the one hand, moisture is insufficient for the successful formation of debris flows; on the other hand, sparse vegetation in the upper parts of the slope and the lower upper border of the forest do not inhibit exogenous processes.Air temperatures in Teberda are 4-5°C lower than in Balkaria. This contributes to the reduction of glacier melting, inhibiting exogenic processes. Higher moisture and the lack of grazing contribute to the formation of rich and dense vegetation, with a similar effect. This factor neutralizes the more active than in the Central Caucasus, frost weathering and high saltitudes, contributing to a higher rate of mobility of both water and debris.

SPF ICE: A Novel Approach to Model the Amount And Effectiveness of Silica to Preserve Glaciers Using Reinforcement Learning

<p>Glaciers cover nearly 10 percent of the earth’s surface but are melting at an inexorable rate. According to the Pacific Standard magazine, the Arctic Sea ice has lost 80 percent of its volume since 1979. Antarctica’s ’Doomsday Glacier’ is melting faster and could raise global sea levels by two feet. As three-quarters of the earth’s fresh water is stored in glaciers, its melting depletes freshwater resources for millions of people. Glaciers also play a huge role in the climate crisis. Silica microspheres are promising materials to prevent glacier melting as it reflects most of the sun’s radiation. When spread in layers over the glacier, it can slow the rate of melt and aid in new ice formation. However, it is necessary to determine the ideal amount of silica to achieve the desired result with minimum environmental impact. This paper introduces a novel method SPF ICE to determine the optimal amount of silica based on glacier’s properties using reinforcement learning agents and a custom OpenAI Gym environment. The environment simulates a real-world model of a glacial setting using specific data, such as the glacier’s mass balance, temperature, and average accumulation and ablation. After testing the agents, the proposed solution reduced glacial melting by an average of 60.40% using the optimal amount of silica. The results indicate SPF ICE is a promising and cost-effective solution to curb glacier melting.<br></p>

SPF ICE: A Novel Approach to Predict the Optimal Amount of Silica to Preserve Glaciers Using Reinforcement Learning

<p>Glaciers cover nearly 10 percent of the earth’s surface but are melting at an inexorable rate. According to the Pacific Standard magazine, the Arctic Sea ice has lost 80 percent of its volume since 1979. Antarctica’s ’Doomsday Glacier’ is melting faster and could raise global sea levels by two feet. As three-quarters of the earth’s fresh water is stored in glaciers, its melting depletes freshwater resources for millions of people. Glaciers also play a huge role in the climate crisis. Silica microspheres are promising materials to prevent glacier melting as it reflects most of the sun’s radiation. When spread in layers over the glacier, it can slow the rate of melt and aid in new ice formation. However, it is necessary to determine the ideal amount of silica to achieve the desired result with minimum environmental impact. This paper introduces a novel method SPF ICE to determine the optimal amount of silica based on glacier’s properties using reinforcement learning agents and a custom OpenAI Gym environment. The environment simulates a real-world model of a glacial setting using specific data, such as the glacier’s mass balance, temperature, and average accumulation and ablation. After testing the agents, the proposed solution reduced glacial melting by an average of 60.40% using the optimal amount of silica. The results indicate SPF ICE is a promising and cost-effective solution to curb glacier melting.<br></p>

SPF ICE: A Novel Approach to Predict the Optimal Amount of Silica to Preserve Glaciers Using Reinforcement Learning

<div><div><div><p>Glaciers cover nearly 10 percent of the earth’s surface but are melting at an inexorable rate. According to the pacific standard magazine, the Arctic sea ice has lost 80 percent of its volume since 1979. Antarctica’s ’Doomsday Glacier’ is melting faster and could raise global sea levels by two feet. As three-quarters of the earth’s freshwater is stored in glaciers, its melting depletes freshwater resources for millions of people. Glaciers also play a huge role in the climate crisis. Preserving glaciers is an important and imminent solution to save our planet. Silica microspheres are promising materials to prevent glacier melting as it reflects most of the sun’s radiation. When spread in layers over the glacier, it can slow the rate of melt and aid in new ice formation. However, if not used precisely, silica can be ineffective and expensive. SPF ICE is a novel method implemented to effectively de- termine the optimal amount of silica based on glacier’s properties to prevent its depletion substantially using reinforcement learning agents and a custom OpenAI Gym environment. The environment simulates a real-world model of a glacial setting using specific data, such as the glacier’s mass balance, tem- perature, and average accumulation and ablation. After testing the agents during many episodes, my solution reduced glacial melting by an average of 60.40% using the optimal amount of Silica. Additionally, this solution is customizable for any type of glacier. SPF ICE is an efficient and low-cost solution to curb glacier melting to preserve planet earth.</p></div></div></div>