The soil water content of different land types in the typical desert-oasis transition zone of Hexi Corridor and Zhangye City, Gansu Province were taken as the research objects to clarify the dynamic changes of soil water content and its relationship with climatic factors, and to reveal the spatial heterogeneity, dynamic changes and the interaction between soil water content and climatic factors in this region, and to provide theoretical basis local ecological protection and desertification prevention and control.

Through field sampling, indoor experiments, data analysis and processing, the changes of soil water content in the and saline-alkali areas of the desert-oasis transition zone in 0-20, 20-40, 40-60, 60-80 cm soil layers were analyzed. The correlation between climatic factors and soil water content was analyzed by Pearson bivariate correlation analysis and the response degree of soil water content to climatic factors was analyzed by grey correlation method.

1) The soil water content in the desert area generally low, with relatively high water content in the 0-20 cm soil layer, which decreased with the increase of depth; the soil water content in the-alkali area was generally high, with the water content increasing first and then decreasing with the increase of depth, and the water content in the 40-60 cm soil layer was the highest. The coefficient of variation of soil water content in different soil layers was at a low level of variation, indicating that its change was stable. The soil water content in the desert and saline-alkali areas showed different change trends in different months, with the highest water content in the 40-60 cm soil layer in the desert area and the lowest in the 60-80 cm soil layer; the highest water content in the saline-alk area was in the 40-60 cm or 60-80 cm soil layer, and the lowest was in the 0-20 cm layer; 2) Soil water content was significantly positively correlated with precipitation and relative humidity, and negatively correlated with wind speed, evaporation and temperature to varying degrees.ipitation and relative humidity had a significant effect on soil water content in the desert area, and precipitation and evaporation had a prominent effect in the saline-alkali, and the grey correlation analysis further revealed the greater effect of relative humidity and precipitation on soil water content in different soil layers.

The soil water content the desert area was generally low, while that in the saline-alkali area was generally high. The soil water content of different land types showed different change trends in months, and there were differences among the soil layers, but the overall change was relatively stable. The distribution of soil water content was affected by seasonal precipitation, evaporation soil texture.

To establish a scientific and reasonable evaluation system of Xanthoceras sorbifolia resources in Hexi, Gansu Province, and to make comprehensive evaluation and screening of excellent varieties of Xanthoceras sorbifolia suitable for local application, to provide a theoretical basis for the development of Xanthoceras sorbifolia ecological industry in arid and semi-arid regions of Hexi Corridor.

Using the analytic hierarchy process (AHP) to build an analytical model to calculate the index weight, using the principle of grey relational grade analysis (GRA) to build “Ideal varieties” and reference series, and calculating the weighted grey relational grade, the 17 introduced new germplasm were evaluated and sorted from adaptability, ornamental and high yield, and finally completed comprehensive evaluation and screening.

On the basis of verifying the rationality of the analytic hierarchy process AHP-RRB- model, the weight values obtained were used to calculate the weighted correlation degree of each germplasm evaluation index, the results showed that the weighted correlation degree of SW-2, SH-2, NSJH, NSZH, LD was above 0.8 (including 0.8) and classified as Grade I germplasm NSF, LX, ZS-7, ZS-9, SW-1, SH-5, SH-5 were classified as Grade II germplasm according to the weighted grey correlation between 0.7 and 0.8(including 0.7). The weighted grey correlation degree of SKX, NH-1, ZS-4, LG-4, LG-8, ZS-1 was less than 0.7 and classified as Grade III germplasm.

The grade I germplasm has high ornamental value, high seed yield, large oil yield and strong adaptability, and its comprehensive scores are close to “Ideal variety” grade II plants have either high ornamental value, general oil potential and low yield, or high yield and good oil yield, but general ornamental value. In a word, their comprehensive characters are slightly worse than those of grade I plants, the germplasm with high ornamental value should be applied in urban landscaping, and the germplasm with high yield and oil yield should be widely planted in Xanthoceras sorbifolia industrial development base, it is suitable for high yield garden, grade III germplasm has poor comprehensive characters, and its ornamental value, yield and oil yield are all average, but this kind of planting is not suitable for local planting, or need to do further introduction and domestication and screening work.