Land Use/Cover Change Impacts on Water Table Change over 25 Years in a Desert-Oasis Transition Zone of the Heihe River Basin, China

Abstract:The Heihe River is the second largest river in arid areas of China, and the irrigation water of oasis agriculture in its middle reaches accounts for almost 80% of the water resources in the whole watershed. Corn is the most important crop in the middle reaches of the Heihe River, and its water consumption is about 50% of the total agriculture water consumption of the middle reaches. Therefore, in order to effectively use the water resources in the watershed, it is crucial to improve the efficiency of corn irrigation. In this paper, using the Ganzhou District in the middle reaches of the Heihe River as the study region, we carried out a field survey to obtain characteristics of seed and field corn. Based on our results, we conducted parameter calibration using the CROPWAT model and calculated the irrigation water requirements (IWR) of these two corn types. The irrigation water requirements of seed and field corn in the growing seasons were 470.1 and 488.5 mm, respectively. However, we observed big differences in the water consumption sequences of these two corn types. Prior to mid-July, evapotranspiration and IWR of seed corn were 14.3% and 20.1% higher, respectively, than those of field corn. In September, IWR of the two corn types started to decrease, with a value of 82.3 mm for seed corn, which was 32.1% lower than the IWR of field corn (108.7 mm) during the same period. However, there were no significant differences in the irrigation time and single irrigation amount for seed and field corn in the study area. Since corn is widely cultivated in the Zhangye Region, there is a considerable water-saving potential in agriculture if the irrigation water consumption can be adjusted according to the IWR of the two corn types.

Section: Introductionmentioning

confidence: 99%

Different Irrigation Water Requirements of Seed Corn and Field Corn in the Heihe River Basin

Tan

Zheng

2017

“…Because of the increasing water resources and eco-environmental problems, the HRB has attracted many researchers' attention in China. In the HRB, there are several studies simulating hydrological processes [25][26][27][28][29][30]. However, there have been few studies conducted to estimate the climate change impact on water balance components in the mountainous watershed at different spatial scales.…”

Section: Introductionmentioning

confidence: 99%

Assessing Variation in Water Balance Components in Mountainous Inland River Basin Experiencing Climate Change

Yin

Feng

Zou

et al. 2016

Abstract:Quantification of the changes of water balance components is significant for water resource assessment and management. This paper employed the Soil and Water Assessment Tool (SWAT) model to estimate the water balance in a mountainous watershed in northwest China at different spatial scales over the past half century. The results showed that both Nash-Sutcliffe efficiency (NSE) and determination coefficient (R 2 ) were over 0.90 for the calibration and validation periods. The water balance components presented rising trends at the watershed scale, and the total runoff increased by 30.5% during 1964 to 2013 period. Rising surface runoff and rising groundwater flow contributed 42.7% and 57.3% of the total rising runoff, respectively. The runoff coefficient was sensitive to increasing precipitation and was not significant to the increase of temperature. The alpine meadow was the main landscape which occupied 51.1% of the watershed and contributed 55.5% of the total runoff. Grass land, forest land, bare land, and glacier covered 14.2%, 18.8%, 15.4%, and 0.5% of the watershed and contributed 8.5%, 16.9%, 15.9%, and 3.2% of the total runoff, respectively. The elevation zone from 3500 to 4500 m occupied 66.5% of the watershed area, and contributed the majority of the total runoff (70.7%). The runoff coefficients in the elevation zone from 1637 to 2800 m, 2800 to 3500 m, 3500 to 4000 m, 4000 to 4500 m, and 4500 to 5062 m were 0.20, 0.27, 0.32, 0.43, and 0.78, respectively, which tend to be larger along with the elevation increase. The quantities and change trends of the water balance components at the watershed scale were calculated by the results of the sub-watersheds. Furthermore, we characterized the spatial distribution of quantities and changes in trends of water balance components at the sub-watershed scale analysis. This study provides some references for water resource management and planning in inland river basins.

“…Previous literature on the relationship between land use change and water resources have been with reference to the groundwater depth and quality [39,44,45], water quality in terms of pollution [46], and water quantity due to overextraction [47]. These studies have used remotely sensed data at a large regional scale.…”

Section: Role Of Land Use Change As a Determinant In The Evaluation Amentioning

confidence: 99%

Evaluating the Functioning Mechanisms of ‘TANK Systems’ in Peri-Urban Areas of Chennai, India—Land Use Change as the Determinant

Harishankar

Vedamuthu

2019

Ensuring the sustenance of water resources that act as sources of water for cities threatened by urbanization and developmental pressures is a crucial problem in peri-urban areas. The objective of this research was to establish the role of change in agricultural land use as a determinant in the evaluation of the existing water management system and to ascertain whether the control by the government or community management can be effective in ensuring the sustenance of water resources in peri-urban areas. The cases selected for the study were the water management systems present in two villages located in the peri-urban areas of Chennai, India. This research adopted a case study strategy with mixed methods of analyses. The analysis traces trajectories of change in the land use of agricultural lands and the common lands related to water management through methods, trend analysis, analysis of spatial patterns of change and the changes in the components of the community management. Results from the analysis indicated that under the context of intensive change from agricultural to nonagricultural land uses, the interlinkages within the traditional community management model had broken up, making community control improbable. The current management model of the government was also found to be inadequate. Results indicated that government agencies with trained personnel engaged in periodic maintenance activities, constant monitoring against encroachment, and pollution, and through the formation of user associations under their control can ensure the sustenance of water resources.