Alkali-activated cement (AAC) is a sustainable building material with low carbon emissions, but it has a growing demand for raw materials. In this study, the potential of low-purity modified calcium bentonite (CB) as a raw material for AAC was evaluated. The thermodynamic changes and pozzolanic properties of calcined CB were determined using X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TG-DTA), zeta potential, and a strength activity index (SAI) test. The compressive strength test, scanning electron microscopy–energy dispersive spectrometer (SEM-EDS), and Fourier-transform infrared (FTIR) spectroscopy were performed to examine the compatibility between CB and AAC. It was revealed that CB is a low-purity clay with low-pozzolanic activity. Calcination enhanced its pozzolanic activity, and the optimum temperature is 750 °C. The incorporation of modified CB improved the mechanical properties of AAC, and low-temperature modified CB had better compatibility with AAC than the high-temperature modified CB. Calcination at 150 °C had little effect on the structure of CB, and the water absorption of montmorillonite increased the ion concentration, increasing the rate and degree of hydration. Furthermore, low-temperature calcination had a dissolution–precipitation effect, resulting in leaf-like CaO·SiO₂·H₂O (C-S-H) gels, whereas the high-temperature calcination of CB was very reactive, resulting in flower-like C(N)-S-H gels.

Xinjiang is located in the arid region of northwestern China, and agriculture accounts for an absolute share of total water use. Resource-based, engineering, structural, and managed water shortages coexist. Therefore, it is of great significance to vigorously develop water conservation technology and improve the efficiency of water transmission and distribution in canal systems. This research aims at addressing the problems of difficult manual regulation and the overall optimization of the final canal system, low-water-resource utilization efficiency, and management efficiency. Taking the branch-double two-stage canal system of Dongfeng branch canal in Mangxiang, Jinghe irrigation district, as a case study, and the rotation irrigation group and irrigation duration as decision variables, canal distribution is modeled with the goal of minimizing seepage losses. The improved grey wolf algorithm combined with particle swarm optimization is used for the first time and compared with the traditional grey wolf algorithm, genetic particle swarm optimization fusion algorithm, and northern goshawk algorithm. The results show that (1) on the basis of meeting the water discharge capacity and water demand requirements of the canal system, the diversion time of the water distribution scheme obtained by using the improved grey wolf algorithm is shortened from 11 d to 8.91 d compared with the traditional empirical water distribution scheme. (2) The improved grey wolf algorithm converges to the optimal value within 10 generations compared to the remaining methods, and the total water leakage is reduced from 16.15 × 10⁴ m³ to 11.75 × 10⁴ m³. (3) The number of gate adjustments is reduced, and the canal gates are opened and closed at the same time within each rotational irrigation group. The grey wolf algorithm improved by its combination with particle swarm has stronger optimization ability and convergence, which can better meet the requirements of efficient water resource allocation in irrigation canal systems, as well as a high application value.

Accurate analysis of soil organic carbon (SOC) under different land uses in ecologically fragile arid zones is essential for effective regulatory measures and improvement of ecological quality. This study selected the ecologically fragile Tarim River source area as an example, aiming to quantitatively assess the SOC content, storage, carbon sequestration potential, and stratification ratio (SR) of different ecological land use types. Soil depths from 0–50 cm were determined and analyzed using the K₂Cr₂O₇-H₂SO₄ oxidation method, the equivalent soil mass method and mathematical statistics. Forest, shrubland, and grassland ecological land types were included. The results show the following: (1) Both SOC content and storage showed a decrease with increasing soil depth. The total SOC content and storage sequence from high to low were natural forest, grassland, and shrubland. (2) There are variations in the SOC sequestration potential among the different ecological land types and shrubland (40.64 Mg C ha⁻¹) > grassland (37.69 Mg C ha⁻¹). (3) The SRs of the SOC in the forest were significantly greater than those in the shrubland and grassland. The different ecological land types had significant impacts on SR2, SR3, and SR4. SR2 could serve as a reliable index for assessing the impact of management practices on soil quality. The study area has a high potential for soil carbon sequestration in the future under these ecological conservation and management measures.

Ecological sluices were constructed along the Tarim River to supplement the ecosystem’s water supply. However, the impact of water regulation by these sluices on the surface water area (SWA) and its relationship with the vegetation response remain unclear. To increase the efficiency of ecological water use, it is crucial to study the response of SWA to water control by the ecological gates and its relationship with vegetation restoration. We utilized the Google Earth Engine (GEE) cloud platform, which integrates Landsat-5/7/8 satellite imagery and employs methods such as automated waterbody extraction via mixed index rule sets, field investigation data, Sen + MK trend analysis, mutation analysis, and correlation analysis. Through these techniques, the spatiotemporal variations in SWA in the middle reaches of the Tarim River (MROTR) from 1990–2022 were analyzed, along with the relationships between these variations and vegetation restoration. From 1990–2022, the SWA in the MROTR showed an increasing trend, with an average annual growth rate of 12.47 km² per year. After the implementation of ecological gates water regulations, the SWA significantly increased, with an average annual growth rate of 28.8 km² per year, while the ineffective overflow within 8 km of the riverbank notably decreased. The NDVI in the MROTR exhibited an upward trend, with a significant increase in vegetation on the northern bank after ecological sluice water regulation. This intervention also mitigated the downward trend of the medium and high vegetation coverage types. The SWA showed a highly significant negative correlation with low-coverage vegetation within a 5-km range of the river channel in the same year and a significant positive correlation with high-coverage vegetation within a 15-km range. The lag effect of SWA influenced the growth of medium- and high-coverage vegetation. These findings demonstrated that the large increase in SWA induced by ecological gate water regulation positively impacted vegetation restoration. This study provides a scientific basis for water resource regulation and vegetation restoration in arid regions globally.

Changes in climate and land type directly affect the transformation and utilization of regional water resources. To analyze the evolutionary characteristics and drivers of agricultural water consumption (AWC) in arid regions, the Baicheng County is selected as an example. Based on the meteorological and land use/cover data from 1990 to 2020, the Penman–Monteith model and sensitivity method were used for analysis. The results show that: (1) The water consumption of major crops during the growth period was increasing, which was caused by climate change and changes in agricultural planting structure. (2) The sensitivity of AWC to meteorological factors was as follows: mean temperature (1.56) > mean wind speed (0.6) > precipitation (−0.12) > sunshine duration (−0.06). Temperature and wind speed were the dominant factors contributing to increased water consumption in oasis agriculture. (3) The change in land type was more obvious, mainly in cultivated land and urban and rural residential land with obvious growth, while the area of water area, forestland, and grassland showed a decreasing trend. In the past 30 years, the increase in cultivated land has reached 24.32%. The increase in cultivated land area was an important reason for the increase in AWC.

Disentangling the responses of total soil organic carbon (SOC), organic carbon fractions and soil aggregate stability to various vegetation types is essential for better understanding the carbon cycling process in terrestrial ecosystems, maintaining soil quality and mitigating global warming. To study the effects of vegetation types on soil aggregates in a specific area, the desert riverbanks of arid regions were studied. We set up experiments using three typical vegetation types in the arid zone of the Tarim River Basin (TRB), including Forestland, Shrubland, and Grassland. The total SOC content in the bulk soil and different soil aggregates was determined by oxidation with K₂Cr₂O₇ and H₂SO₄, and three carbon fractions (F1, very labile; F2, inert; F3, oxidizable resistant) were classified according to the degree of oxidation using the modified Walkley-Black method. The total SOC and three carbon fractions in the soil were significantly greater in the Forestland than in the other vegetation types, and the effect was more pronounced in macro-aggregate (MA) than in the other aggregates. In the bulk soil and soil aggregates, the percentages of F1, F2 and F3 in the total SOC with mean values of 0.36%, 0.28% and 0.36%, respectively, at soil depths of 0–20 cm, indicated that stabilizing carbon is the major carbon fraction of the SOC. The stability of the SOC in the aggregates across each vegetation type was greater in the lower layer (10–20 cm) than in the topsoil layer (0–10 cm). The SOC stability and MA content were positively related to the SOC in the soil aggregates and its F2 and F3 fractions (p < 0.05). In summary, the Forestland significantly increased the SOC content and enhanced SOC stability. Conservation measures for poplar forests in vulnerable arid zones can sustainably accumulate SOC sequestration.