Jing River Research Articles

An examination of the fluctuation and long-term persistence of drought regimes in the Jing River basin using the PDSI–SWAT model

An examination of the fluctuation and long-term persistence of drought regimes in the Jing River basin using the PDSI–SWAT model

Research on the risk of drought disasters in the middle reaches of the Yellow River coupled with ecosystem entity

ABSTRACT Drought is one of the most significant natural disasters. In this study, we utilized the middle reaches of the Yellow River as the subject of our investigation. We characterized the exposure of ecosystem disaster-bearers by NDVI and established a probabilistic framework for assessing the vulnerability of ecosystems under drought stress, coupling ecosystems and human society disaster-bearers. The SPI was selected to identify the attributes of drought by employing the travel theory, and the bivariate joint distribution of drought duration and intensity was constructed by utilizing the Copula function. The temporal and spatial changes in drought risk in the middle reaches of the Yellow River are investigated using the risk calculation formula defined by the IPCC. The results indicate that a few areas, including the Wei River, Wuding River, Fen River, and Yiluo River basins, are prone to drought events with low drought duration and low drought intensity. The drought risk exhibited an upward trend, gradually expanding outward from the mainstem area. The area of high drought risk in the two-variable AND relationship migrated upstream from the downstream of the Wuding River, the Beiluo River, the Jing River, the Wei River, and the Fen River.

Climate Change and Vegetation Greening Jointly Promote the Increase in Evapotranspiration in the Jing River Basin

Within the Earth’s terrestrial environment, evapotranspiration significantly contributes to the hydrological cycle, accounting for around 80% of the precipitation on landmasses to be reintroduced into the atmosphere. This mechanism profoundly affects the distribution and availability of surface water resources throughout the ecosystem. Gaining insight into the factors influencing local evapotranspiration fluctuations in response to varying climatic and vegetative scenarios is crucial for effective water management strategies and rehabilitating ecosystem resilience. To this end, our study focuses on the Jing River Basin in the Loess Plateau, utilizing multi-source remote sensing data and climatic information to investigate the spatiotemporal dynamics of evapotranspiration from 1984 to 2018 through the application of the Priestley–Taylor Jet Propulsion Laboratory (PT-JPL) model. Our research results indicate a general ascending tendency in evapotranspiration across the investigated region, demonstrating a notably discernible escalation at a pace of approximately 3.11 mm/year (p < 0.01), with an annual vegetation ET volume reaching 533.88 mm. Across different vegetation types in the Jing River Basin between 1984 and 2018, the mean yearly ET was observed to be highest in forests (572.88 mm), followed by croplands (564.74 mm), shrublands (536.43 mm), and grasslands (503.42 mm). The leaf area index (LAI) demonstrated the strongest partial correlation with ET (r = 0.35) and contributed the most significantly to the variation in ET within the Jing River Basin (0.41 mm/year). Additionally, LAI indirectly influences ET through its impact on vapor pressure deficit (VPD), precipitation (Pre), and temperature (Temp). Radiation is found to govern most ET changes across the region, while radiation and precipitation notably affected ET by modulating air temperature. In summary, these radiant energy changes directly affect the evaporation rate and total evapotranspiration of surface water. It provides important support for understanding how evapotranspiration in the Jing River Basin is adjusting to climate change and increased vegetation cover. These findings serve as a theoretical foundation for devising sustainable vegetation restoration strategies to optimize water resource utilization within the region.

Future spatial and temporal variation of blue and green water in the Jing River Basin of central China under changing climatic conditions

Future spatial and temporal variation of blue and green water in the Jing River Basin of central China under changing climatic conditions

Can the best management practices resist the combined effects of climate and land-use changes on non-point source pollution control?

Climate and land-use changes have an overlying impact on non-point source (NPS) pollution in river basins. However, the control effect of Best Management Practices (BMPs) for NPS pollution is not yet clear under future scenarios. The Soil and Water Assessment Tool (SWAT) model was coupled with the entropy-weighted method, global climate patterns and land-use data to explore the dynamic variations in total nitrogen (TN) and total phosphorus (TP) loads in the Jing River Basin during the baseline (2000−2020) and future periods (2021–2065), evaluate the pollution reduction effectiveness of individual and combined BMPs, and propose practical BMP configurations. Results indicate that a future trend of urban land expansion, particularly in the economic scenario (LU_SSP585), leads to weakened environmental ecosystems, while the sustainable scenario (LU_SSP126) exhibits more balanced land development. The MIROC-ES2L model demonstrates higher Taylor skill scores, forecasted significant increases in precipitation, maximum, and minimum temperatures under the SSP585 scenario. Spatial heterogeneity in TN and TP loads is notable, showing an upward trajectory in the future. The interaction between land-use and climate change has complex effects on TN and TP loads, with land-use-induced TN changes being relatively small (4.6 %) and TP changes substantial (24.3 %). The spatial distribution, under overlying effects, leans towards the influence of climate change, emphasizing its dominant role in TN and TP load variations. Distinct differences exist in the reduction of NPS pollution loads among different BMPs, with combined BMPs demonstrating superior effectiveness. The environmental-cost effectiveness trends of BMPs remain consistent across various future scenarios. RG (Return agricultural land to grass), RG + TT (Terracing), and RG + FR10 (Fertilizer reduction: 10 %) + GW (Grassed waterway) + FS (Filter strip) + TT emerge as the most effective single, double, and multiple BMP combinations, respectively. The results offer valuable insights for preventing and mitigating future NPS pollution risks, optimizing land-use layouts, and enhancing watershed management decisions.

The study on spatial distribution of water ecological environment carrying capacity during extreme drought conditions

Due to global warming and the disturbance of the interannual variability of precipitation, the frequency of extreme drought events has increased. The impact of global climate change on water resources is becoming increasingly apparent, then it is particularly necessary to explore the carrying capacity of water ecological environment under extreme drought conditions, which can guarantee the ecological water security in river basins. This study takes the Guanzhong area of the Wei River Basin as an example, calculating the water environment carrying capacity of 40 areas in the Weihe Guanzhong area in different levels of years under extreme drought conditions by comprehensive evaluation model of carrying capacity and using geographic information system GIS to display the spatial distribution of water environment carrying capacity in 40 regions. According to the results of the spatial distribution of water environmental bearing capacity, four different schemes are designed to improve the bearing capacity. The first plan reduces the industrial water consumption and irrigation quota by 5%, the second plan increases the industrial water and sewage treatment rate on this basis. the third plan further improves the development and utilization rate of surface and groundwater, and the fourth plan, on the basis of the first three plans, supplies 600 million cubic meters of industrial and agricultural water to Guanzhong region. Through comparative analysis, without taking any measures, under the extreme drought conditions, the water environment carrying capacity of the 40 areas in Guanzhong is all in an unbearable state. Overall, plan 4 has the most significant improvement in the water environment-carrying capacity, especially the Dong zhuang Reservoir of the Jing River which has played a very important role in enhancing the water ecological environment carrying capacity of the downstream water of the Wei River.

Response of Runoff Change to Soil and Water Conservation Measures in the Jing River Catchment of China

Soil and water conservation measures (SWCMs) are vital in reducing runoff and ultimately affect water security and regional development. However, previous studies have mainly focused on the impact of a single SWCM, neglecting to distinguish between the effects of different SWCMs on runoff reduction. A Soil and Water Assessment Tool (SWAT) model was established in the Jing River catchment to identify the responses to runoff changes resulting from climate change and human activities. The model was used to quantitatively analyse the impact of different SWCMs on runoff reduction. The results indicated that human activities contributed significantly more to runoff reduction than climate change. The reduction benefits of different unit area changes for each SWCM on discharge, surface runoff and water yield at the outlet were ranked as follows: changing cultivated land to forest land > changing cultivated land to grassland > building terraces on a 5–15° slope > building terraces on a 5–25° slope > building terraces on a 15–25° slope. Regional authorities should comprehensively consider the effects of various SWCMs on water reduction, and optimise the layout of vegetation and terracing measures, to support the efficient utilization of water resources in the Jing River catchment.

Integrating satellite and reanalysis precipitation products for SWAT hydrological simulation in the Jing River Basin, China.

In hydrological studies, satellite and reanalysis precipitation products are increasingly being used to supplement gauge observation data. This study designed the composite simulation index (COSI), considering two factors: F1 (data accuracy assessment) and F2 (hydrological simulation performance), to compare the performance of the latest satellite-based and reanalysis-based precipitation products (IMERG, ERA5, ERA5-Land), the prior precipitation products (TRMM, CMADS), and the multi-source weighted-ensemble precipitation (MSWEP). The Soil and Water Assessment Tool (SWAT) model was then applied to compare and analyze the hydrological simulation performance of four preferred products using three data fusion methods including simple model averaging, variance-based weighted averaging, and the latest quantile-based Bayesian model averaging (QBMA). The results can be summarized as follows: (1) Reanalysis products are superior to satellite-based products in terms of F1. However, the satellite-based precipitation products exhibit less BIAS and relatively higher F2, while the MSWEP has relatively high performance on both F1 and F2. (2) Among reanalysis-based precipitation products, CMADS has the best COSI value of 0.53. Although ERA5-Land shows good performance for individual parameters, the comprehensive assessment reveals that ERA5 outperforms ERA5-Land in terms of both F1 and F2. (3) IMERG and TRMM exhibit similar spatiotemporal patterns and similar F1, but IMERG is superior in F2. (4) QBMA outperformed traditional methods in F2, improving the NS coefficient of SWAT model from 0.74 to 0.85. These findings provide a useful reference for analyzing the strengths and limitations of satellite-based and reanalysis precipitation products, and also provide valuable ideas for the combined application of multi-source precipitation products in hydrological studies.

Archaeological Survey and Lithic Artifacts Analysis of Prehistoric Sites in the Upper Jing River Basin, China

ABSTRACT The Jing River Basin is one of the birthplaces of Chinese civilization, but there has been no systematic research on prehistoric archaeology in this region to date. Recently, researchers conducted archaeological surveys of four prehistoric sites in the upper reaches of the Jing River and collected a batch of lithic artifacts. This article employs a combined approach of typological analysis and technique analysis to study the lithic artifacts. Results show that the operational method involves core preparation and flaking by direct percussion. Compared to other prehistoric sites in China, it is evident that the discovered sites belong to the prehistoric culture of the upper Yellow River region. By combining the collected pottery, it can be more precisely determined that the four sites surveyed in this investigation represent the Qijia Culture of the Neolithic period. This is a unique prehistoric culture in the northwest of China.

A VIEW FROM THE COUNTRYSIDE: RADIOCARBON CHRONOLOGY FOR ZAOLINHETAN OF THE PRE-ZHOU CULTURE IN EARLY DYNASTIC CHINA

ABSTRACTThe conquest of the Shang Dynasty at Anyang around 1046 BCE by the Zhou is one of the major events for not only Chinese Bronze Age but also early interaction between the pastoralist groups from the Eurasian Steppes and agriculture ones in the Central Plains of China. It is well-known from historical texts that the pre-Zhou people lived in the ancient Bin region (豳), the exact location of which is unclear, but most likely in the Jing River valley. At some point the leader Gugong Danfu (古公亶父) moved from Bin to the capital Qi (Zhouyuan), which preceded the Zhou invasion of Anyang. We have produced a new high resolution radiocarbon chronology for Zaolinhetan, a small settlement in the pre-Zhou heartland. This shows not only an exceptionally long chronological span for the site, but also a different phasing compared to the traditional pottery typology, which raises new questions regarding the regional variation of pottery typologies. Intriguingly, the analysis also reveals a rapid abandonment of Zaolinhetan around 1100 BCE, at the same time many larger sites, such as Zhouyuan, which later became the capital of the Western Zhou dynasty, were significantly expanding. We argue that the drastic decline of Zaolinhetan as revealed by the substantial number of radiocarbon dates and probably also the movement of pre-Zhou political center from Bin to Qin, was part of bigger picture that involved a range of social and environmental factors.

A spatial optimal allocation method considering multi-attribute decision making and multiple BMPs random combination in sub-watersheds

Best management practices (BMPs) have been extensively employed in effective watershed management for non-point source pollution. The weights of objective functions and the restrictive conditions of combined BMPs are the vital requirements for BMPs allocation. Therefore, it is more beneficial to explore that a spatial optimal allocation method considering multi-attribute decision making and multiple BMPs random combination. Here is the novel framework based on Soil and Water Assessment Tool (SWAT) and the Non-dominated Sorting Genetic Algorithm II (NSGA-Ⅱ), which considers multiple objectives in deriving watershed-scale pollution control practices by considering BMPs cost and combined reduction rates of total nitrogen (TN) and total phosphorus (TP). The framework also integrates combined Entropy Weight method (EWM) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) to solve the weights of TN and TP, and considers the attributes of the sub-basin itself, which is more local suitability. Four categories of BMPs, tillage management, nutrient management, vegetative filter strips, and landscape management, were evaluated in the Jing River Basin (JRB) and resulted in reduction rates of 9.77%, 10.53%, 16.40%, and 14.27% averagely, respectively. BMP allocation schemes, derived from multi-objective optimization, are stratified into three financial scenarios. Low-cost scenario, costing up to 2 billion RMB, primarily targets the grain for green program in 28.81% of sub-basins. Medium-cost scenario, between 2 and 6 billion RMB, predominantly utilizes the grain for green in areas with a slope greater than 15°, accounting for 20.00% of sub-basins. High-cost scenario exceeds 6 billion RMB, mainly due to the implementation of multiple combination measures. The three configuration scenarios can provide decision-makers with a trade-off between measure costs and reduction efficiency. Overall, the innovative framework not only facilitates cost-effective implementation but provides a beneficial methodology for selecting cost-effective conservation practices in other regions.

Identification of critical source areas and delineation of management subzones of non-point source pollution in Jing River Basin

Identification of critical source areas and delineation of management subzones of non-point source pollution in Jing River Basin

Ecological flow research and optimal selection of the most ecologically relevant hydrologic indicators at the Jingjiang River's three outlets

Abstract Scientific ecological hydrological indicators provide constraints that contribute to the healthy operation and restoration of river ecosystems. Daily flow data from three Jing River outlets (SongZiKou (SZK), TaiPingKou (TPK), and OuChiKou (OCK)) spanning 1955–2019 were used. We employed innovative methods, such as IHA–RVA and annual distribution, to establish ecological flow thresholds. Surplus and deficit indicators were used to analyze annual and seasonal runoff dynamics. The PCA/RVA method identified relevant hydrological indicators and assessed hydrological changes influenced by the Three Gorges Reservoir (TGR). Key findings include suitable ecological flow thresholds for the flood season (SZK/TPK/OCK – 218.6/94.5, 51.7/96.0, and 60.9–4,494.5 m3/s, respectively). The TGR impacted the flow duration curve, causing deficits during the flood season (up to 0.99, OCK) and surpluses in non-flood seasons (up to 5.04, OCK). The study assessed the Jing River watershed's response to hydrological changes, notably due to the reservoir's water storage and flow interruption during the dry season, revealing declining low pulse count (SDG) and duration (MTS) and increasing high pulse duration (GJP). This research employs innovative methods and hydrological indicators, enhancing understanding of Jing River watershed ecological hydrology, and offering essential data for water resource management and ecosystem health.

CMADS and CFSR Data-Driven SWAT Modeling for Impacts of Climate and Land-Use Change on Runoff

Climate and land-use change significantly impact hydrological processes and water resources management. However, studies of runoff simulation accuracy and attribution analysis in large-scale basins based on multi-source data and different scenario projections are limited. This study employed the Soil and Water Assessment Tool (SWAT) model in conjunction with spatial interpolation techniques to evaluate the accuracy of Climate Forecast System Reanalysis (CFSR), China Meteorological Assimilation Driven Dataset (CMADS), and observation (OBS) in runoff simulations, and configured various scenarios using the Patch-generating Land-use Simulation (PLUS) model to analyze effects of climate and land-use changes on runoff in the Jing River Basin from 1999 to 2018. Results demonstrated the superior performance of the CMADS+SWAT model compared to than CFSR+SWAT model, as the latter underestimated peak runoff. Changes in precipitation had a stronger impact on runoff than temperature, with increased flow from farmland and strong interception effects from forestland. Integrated climate and land-use changes led to an average annual runoff reduction of 1.24 m3/s (I2), primarily attributed to climate change (1.12 m3/s, I3), with a small contribution from land-use change (0.12 m3/s, I4). CMADS exhibited robust applicability under diverse scenarios, effectively enhancing runoff simulation accuracy. The findings provide invaluable guidance for water resources management in semi-arid regions.

Study on hydrological response of runoff to land use change in the Jing River Basin, China.

Land use change greatly affects the runoff characteristics of the basin, which in turn affects the distribution of surface water and groundwater in the region. Quantitative analyses of the hydrological response of watershed runoff to land use change are conducive to the formulation of sustainable water resource strategies. In this paper, the impact of land use change on runoff characteristics in the Jing River Basin was evaluated using the SWAT model, the land use pattern of the Jing River Basin in 2040 was predicted using CA-Markov model, and five land use change scenarios were set up in combination with the trend of land use transfer, and the response relationship between land use change and runoff hydrological characteristics in the basin was studied. The results show that the land use changes reduce runoff and change the hydrological cycle process of the basin. The hydrological response of different land use types varies significantly, but only has a less impact on annual runoff. Farmland has a promoting effect on production flow; woodland and grassland are not conducive to the formation of surface runoff and will increase underground runoff and evapotranspiration in the basin. The increase in vegetation coverage after returning farmland to woodlands and grasslands has reduced surface runoff, increased the recharge of groundwater, and played a positive role in ecological restoration in the river basin. The research results are of great significance for understanding the hydrological consequences of land use change and the rational planning of land use patterns in river basins.

Simulation of Hydrological Processes in the Jing River Basin Based on the WEP Model

Inappropriate vegetation reconstruction in the Loess Plateau region has led to a significant increase in regional evapotranspiration and water consumption, further aggravating the shortage of soil water resources in the Loess Plateau region. The Jing River basin is a typical area for vegetation reconstruction in the Loess Plateau region. A thorough understanding of changes in hydrological processes in the Jing River basin is of significant scientific importance for efficient utilization of soil water resources and sustainable vegetation restoration in the region. In this study, the physically based Water and Energy Transfer Processes (WEP) distributed hydrological model was used to simulate key hydrological processes in the Jing River Basin during different periods before and after the implementation of cropland conversion to forest and grassland from 1980 to 2019. The results showed that after the implementation of cropland conversion to forest and grassland from 2000 to 2019, the average runoff volume in the Jing River Basin decreased by 20.91%. The most significant decrease in average runoff occurred in the central and northern parts of the basin, with a maximum reduction of 48.6%. The decrease in runoff in flood season is more obvious. The peak discharge decreased by 24.91%, and the most significant decrease occurred in the northern and central parts of the basin, ranging from 10.3% to 50.2%. The spatial distribution pattern of average soil moisture in the 0–0.8 m soil layer showed more moisture in the south and less in the north, with the minimum value occurring in certain areas in the eastern part of the basin. Overall, the implementation of cropland conversion to forest and grassland led to a certain degree of decrease in soil moisture in the basin. After the implementation of cropland conversion to forest and grassland, reference evapotranspiration fluctuated only in specific areas of the basin with no significant overall change.

Natural revegetation has dominated annual runoff reduction since the Grain for Green Program began in the Jing River Basin, Northwest China

The Grain for Green Program (GFGP) has successfully increased the vegetation cover in northern China over the last two decades through large-scale natural and artificial revegetation approaches. Unfortunately, an obvious runoff reduction has been observed in many basins, especially on the semiarid Loess Plateau. Past studies generally attributed this runoff reduction to the artificial revegetation of the GFGP, i.e., the land cover type change from cropland to forest, since there was no significant annual precipitation decrease. Such cognition has led to widespread concern about the hydrological effects of the GFGP. In fact, in addition to artificial revegetation, natural revegetation relies on natural processes of vegetation succession without land cover type changes directed by humans. Therefore, it is necessary to separate and quantify the contributions of natural and artificial revegetation to runoff reduction to assess the GFGP and optimize revegetation in the future. In this study, the contributions of natural and artificial revegetation to annual runoff change after the implementation of the GFGP were quantified in fifteen subbasins of the Jing River Basin in the central Loess Plateau. The mean annual runoff of the Jing River Basin decreased by 11.8 mm after the GFGP, although the climate (precipitation and potential evapotranspiration) inversely increased the mean annual runoff by 6.6 mm. This is due to that the direct effect of climate change was much less than the ecohydrological effect of revegetation on runoff reduction, i.e., the revegetation caused the mean annual runoff reduction of 18.4 mm. Natural revegetation (50.5% of basin area) was the dominant reason for runoff reduction rather than artificial revegetation (9% of basin area). The natural revegetated area with vegetation quality improvement, i.e., an NDVI increase without land cover type change, contributed to a runoff reduction of 15.5 mm, accounting for 131.1% of the total runoff reduction after the GFGP, and the grassland of natural revegetation was the main vegetation type, with runoff reductions of 9.8 mm. However, artificial revegetation by area increase and quality improvement, i.e., NDVI increase, contributed to a runoff reduction of 8.4 mm, accounting for 49.6% of the total runoff reduction. These results demonstrated that the GFGP needs to be properly adjusted, i.e., natural revegetated areas should be opened in a timely manner and properly utilized, and improving vegetation quality improvement rather than increasing vegetation area would be a priority management measure in artificial revegetated areas.

Investigation of water quality and aquatic ecological succession of a newly constructed river replenished by reclaimed water in Beijing

The potential to create new ecosystems in rivers is possible through the use of reclaimed water as a replenishment source, although the long-term effects of this method are unknown. In this study, the water quality and aquatic ecological evolution of a newly constructed river replenished by reclaimed water in Beijing (the Jing River) were investigated, and the conventional water quality, phytoplankton indicators, and submerged plant growth conditions from October 2018 to December 2020 were analyzed. Spearman's correlation and redundancy analysis between possible influential environmental factors and algal indicators were conducted. The results show that the major water quality indicators could meet the water quality standards for landscape water. There were seven phyla present, including 322 species of phytoplankton. The phytoplankton density increased, followed by a decreasing trend. Phytoplankton densities at each monitoring site reached 10 × 106 to 25 × 106 cells/L in 2019 before decreasing in 2020, then ranging from 8 × 106 to 20 × 106 cells/L. Phytoplankton growth was influenced by changing water quality and ecosystems. Consequently, the submerged plant coverage rate gradually increased from 2018 (0%) to 2020 (26.27%–37.06%), as did biodiversity. Through the implementation of ecological restoration measures in the Jing River, the reclaimed water environment evolved into a more natural water environment, which could provide some reference for similar areas to use reclaimed water as a water replenishment source.

Reconstructed Jing River streamflow from western China: A 399-year perspective for hydrological changes in the Loess Plateau

The Jing River is a secondary tributary of the Yellow River, which flows through the middle of the Loess Plateau in China. Severe water scarcity and soil erosion in the basin have threatened sustainable social and economic development. To assess and solve the region’s water resource problems, it is important to understand its historical hydrological climate change. Accordingly, we used five machine learning models and simple linear regression to reconstruct the January-June streamflow of the Jing River based on the tree ring width of Pinus tabulaeformis and Pinus armandii. By combining six models into an ensemble streamflow reconstruction, we obtained a more accurate reconstruction and streamflow variability information than with a single model. Over the past nearly four centuries, the Jing River has experienced seven high streamflow periods and ten low streamflow periods. The main atmospheric forcing factors driving the streamflow variability are the Pacific Decadal Oscillation and the El Niño-Southern Oscillation, which regulate the climate and hydrology of the region by affecting water vapor fluxes and the Asian monsoon. The different climate scenarios revealed the continued reduction in the future Jing River streamflow and a worsening water resource situation. This new streamflow reconstruction can serve as a valuable reference for analyzing regional hydrology and informing water resource management and policy formulations.

Faunal exploitation during the Proto-Zhou period in the Jing River Valley: Evidence from Sunjia and Xitou

This study examines faunal assemblages from the Proto-Zhou sites of Sunjia and Xitou, in the Jing River Valley (Central Shaanxi Province), to address questions concerning the exploitation of different animal resources in the context of the Shang-Zhou dynastic transition in the 11th century BCE. Although the assemblages from Sunjia and Xitou were small and sub-optimally preserved, this study demonstrates that the inclusion of such assemblages is essential to building upon our understanding of the human exploitation of animal resources. Our zooarchaeological analysis shows an increase in husbandry, with pig farming being complemented by extensive caprine and cattle herding. A diversified use of animal resources, and especially the larger number of bovids, could have been prompted by the need for a wider and more efficient exploitation of the immediate environment, in response to growing climatic deterioration, in addition to an increase in interactions with northern pastoral communities. Identified patterns of livestock biometry and relative taxonomic abundance show various degrees of agricultural engagement and a relatively complex livestock economy, suggesting the development of socio-economic complexity in the Jing River Valley in the late second millennium BCE.